- Open Access
Accuracy of p53 and ki-67 in the graduation of phyllodes tumor, a model for practical application
Surgical and Experimental Pathology volume 3, Article number: 7 (2020)
The accurate graduation of a phyllodes tumor (PT) is critical for effective treatment as it allows correct surgical management, and avoids inadequate excision for malignant or borderline PT, or surgical overtreatment in benign PT. PTs of the breast are notoriously difficult to classify, and reliable differentiation of a benign PT from a borderline or malignant PT can be problematic, especially among relatively inexperienced pathologists. Although several authors acknowledge a strong relationship between the immunohistochemical expression of p53 and Ki-67 and the histopathological grade of PT—with potential impact on diagnostic accuracy—the literature lacks consensus about which cutoff defines a positive index test. The objective of this study is to establish a practical application score that increases the graduation accuracy of PT through the appropriate use of these auxiliary methods.
A retrospective study cohort of 146 pathology reviewed PTs surgically removed between January 2000 and December 2015. The Ki-67 test was considered positive if > 10% of neoplastic cells showed nuclear staining. The p53 test was considered positive if > 10% of neoplastic nuclear cells showed nuclear staining in a moderate or strong intensity.
Of the 146 PT cases reviewed, 110 were classified as benign, 16 as borderline, and 20 as malignant. The correlation between age and size with benign, borderline, and malignant subgroups was statistically significant (p < 0.001). Significance was observed in the expression of both Ki-67 and p53 in the comparison of benign, borderline, and malignant PT with p < 0.001 and a 95% confidence interval (CI). When correlating the presence of positivity in either of the two index tests with the diagnosis of borderline or malignant PT, we reached a sensitivity of 100% and a specificity of 91.8 (p < 0.001; 95% CI).
We propose a practical methodology to achieve an accurate grade of PT, based on clearly defined and easy to apply cutoffs of a simple immunohistochemical panel of Ki-67 and p53. A PT positive for either of the index tests should be graded as borderline or malignant, so pathologists can use this test to improve accuracy. We hope this new approach might provide the basis for the development of standardization in using p53 and Ki-67 for grading PT.
A phyllodes tumor (PT) is the least common lesion in the category of fibroepithelial tumors of the breast, which has fibroadenoma as its common exponent (Tan et al. 2016; Mishra et al. 2013). These are quite unusual lesions, which correspond to 0.3 to 0.5% of all female breast tumors, and are composed of variable proportions of epithelial cells (the non-neoplastic component of lesion), and stromal cells (the neoplastic component of the tumor) (Tan et al. 2016; Lakhani 2012).
In addition to the rarity, the anatomopathological diagnosis is complicated by the complex nature of microscopic morphology associated with the differential diagnosis with morphologically similar lesions, and by its biological behavior depending on the graduation (Lakhani 2012; Lawton et al. 2014). PT of the breast covers a broad spectrum of biological behavior ranging from benign to the frankly malignant (Lakhani 2012; Chang et al. 2018; Tan et al. 2005a). Pathological diagnosis is the gold standard in the definition of these entities with different biological behaviors (benign, borderline and malignant), has a high correlation with recurrence-free survival, and is used in counseling and clinical management (Chang et al. 2018; Chng et al. 2018; Rakha et al. 2017). Studies have provided evidence that only two types of PTs could be distinguished at genetic basis—benign and malignant/borderline (Pareja et al. 2017; Lae et al. 2007). Complete surgical resection is the established treatment for breast PT, since residual PT at the excision margins is a strong predictor of local recurrence; however there is a consensus that benign PTs benefit from more conservative treatment (Tan et al. 2016; Lakhani 2012; Tan et al. 2012; Yonemori et al. 2006; Tremblay-LeMay et al. 2017; Shaaban and Barthelmes 2017). The graduation of PT is based on a constellation of microscopic parameters, which include (i) the degree of cellular atypia of stromal cells; (ii) the degree of stromal cellularity; (iii) the evaluation of the mitotic index in 10 microscopic high-power fields (HPF); (iv) stromal overgrowth; and (v) the characteristics of surgical margins (Tan et al. 2016; Lakhani 2012; Tan and Tan 2018). Since each of the three main morphological parameters (stromal atypia, stromal cellularity and mitotic index evaluation) presents three levels of stratification, there are significant challenges in the search for accuracy and diagnostic reproducibility (Rakha et al. 2017; Khazai et al. 2015).
Beyond the dispute regarding the histopathology of PTs, investigators have studied the role of the biological markers and their relationship with clinical and pathological characteristics, with p53 and Ki-67 perhaps being the most widely evaluated (Yonemori et al. 2006; Tan et al. 2005b; Pornchai et al. 2018; Vilela et al. 2014; Kucuk et al. 2013; Yemelyanova et al. 2011; Noronha et al. 2011; Tse et al. 2002; Umekita and Yoshida 1999; Kim and Kim 1993).
P53 is a tumor suppressor gene located on the short arm of chromosome 17p, and P53 mutations are among the most common identifiable genetic abnormalities in human cancer. The wild-type p53 gene product has a short half-life, and this unstable protein is thus rarely detectable by immunohistochemistry. In contrast, immunohistochemical positivity is believed to highlight the expression of mutant p53 protein, which is more stable with a longer half-life. Not all mutations result in immunopositivity, while positive staining may reflect events other than mutation, such as stabilization of wild-type p53 by cytoplasmic factors. Nevertheless, extensive immunohistochemical positivity for p53 increases the likelihood that there is an underlying mutation. It is commonly used as a surrogate method for tumor-suppressor gene mutation, since the sequencing of the P53 gene carried out by various authors has mostly discovered mutations (Feakins et al. 1999; Giacomazzi et al. 2013; Rivlin et al. 2011; Hanahan and Weinberg 2000; Munawer et al. 2012; Gatalica et al. 2001; Murnyak and Hortobagyi 2016).
Cellular proliferation is one of the fundamental biological processes, and its assessment provides useful predictive information with a growing body of evidence for the utility of Ki-67 for predicting prognosis in many different tumor entities (Vilela et al. 2014; Kucuk et al. 2013; Noronha et al. 2011; Umekita and Yoshida 1999; Munawer et al. 2012; Chan et al. 2004). Ki67 is expressed in proliferating cells during the mid-G1 phase, increasing in level through S and G2, and peaking in the M phase of the cell cycle. It is rapidly catabolized at the end of the M phase, and is undetectable in resting (G0 and early G1) cells (Tan et al. 2005c).
Although PT reports are quite controversial when correlating expression of p53 and Ki-67 with clinical variables, such as global survival and recurrence-free survival, most authors point to a strong relationship between the expression of these markers and the histopathological potential impact on graduation accuracy, even though this was not the original objective of the studies (Lae et al. 2007; Yonemori et al. 2006; Tan et al. 2005b; Vilela et al. 2014; Kucuk et al. 2013; Yemelyanova et al. 2011; Noronha et al. 2011; Tse et al. 2002; Umekita and Yoshida 1999; Kim and Kim 1993; Feakins et al. 1999; Rivlin et al. 2011; Munawer et al. 2012; Gatalica et al. 2001; Murnyak and Hortobagyi 2016; Chan et al. 2004; Tan et al. 2005c; Kim et al. 2018; Wang et al. 2017; Mastellaro et al. 2017; Piscuoglio et al. 2016; Vidal et al. 2015; Lin et al. 2014; Korcheva et al. 2011; Appel et al. 2008; Zlobec et al. 2006; Niezabitowski et al. 2001; Birch et al. 2001; Millar et al. 1999; Kocova et al. 1998; Kawai et al. 1994).
The objective of this study is to establish a positivity score for p53 and Ki-67 that allows the increase of graduation accuracy of PTs through the appropriate use of these ancillary methods. There is no consensus in the literature regarding (i) the percentage of ki67 that has discriminant power in relation to the degrees of PTs; and (ii) the intensity of staining and the percentage of expression of p53 that can be considered as a positive result.
A retrospective study cohort of 146 consecutive PTs surgically removed between January 2000 and December 2015. With the aim of reducing the biases usually related to retrospective studies in which the index test is not performed in order to be evaluated—resulting in non-standardized and not always blinded analysis in relation to the reference standard (Bossuyt et al. 2015)—all cases were reviewed based on current histopathological classification, and all immunohistochemical markers were performed at one time. Both were interpreted by the pathologist blinded to the diagnosis and the clinical status.
The archives of the Department of Pathology of Hospital de Clínicas de Porto Alegre, and more two pathology laboratories of the city, were searched for PT surgically removed between January 2000 and December 2015. The diagnostic slides and formalin-fixed, paraffin-embedded tissue blocks of 146 consecutive benign, borderline, and malignant PTs were retrieved. Cases with no sufficient material for all analysis were excluded. All samples were anonymized prior to pathological analysis, and ethical approval was received from the institution.
A blinded review of all 146 cases, including all tumor sections (according to the latest WHO criteria) (Lakhani 2012) was performed by a pathologist without knowledge of the anatomopathological report or any clinical data, and the results were compared with the original diagnosis. The reviewed diagnosis was assumed as the gold standard for analysis.
A representative paraffin block for each case was chosen for immunohistochemical analysis. Two slides of formalin-fixed, paraffin-embedded sections, 4 μm in thickness, were prepared and affixed to electrostatically charged slides. After deparaffinization and rehydration in xylene and graded alcohols, endogenous peroxidase was blocked with hydrogen peroxide. Antigen retrieval—as in all staining processes—was performed on the Ventana BenchMark automatic staining system (Ventana, Tucson, AZ). Mouse monoclonal antibodies directed against Ki-67 (clone 30–9, prediluted, Ventana) and human p53 (clone DO-7 prediluted, Ventana) were used. Antigen-antibody reactivity was detected using the multimer Ventana detection kit with 3,3′ diaminobenzidine tetrahydrochloride as chromogen. Positive controls were included in all slides.
The stained sections for Ki67 were considered to be positive only if unequivocal nuclear staining was present, no matter the intensity, according to the recommendations of the International Ki67 in Breast Cancer Group (Dowsett et al. 2011). The most active areas—hot spots—with the maximal number of nuclei staining were chosen to perform counting. The Ki-67 index was defined as the percentage of cells that showed a positive staining in 10 microscopic HPF using a 40× objective with an eyepiece of 10× (0.28mm2 area), as previously described (Kocova et al. 1998; Jacobs et al. 2005). Thereafter, a receiver operating characteristic (ROC) curve was used to determine the best cutoff point for the test.
The intensity of the immunohistochemical neoplastic stromal nuclear staining for p53 was scored as negative (0), weak staining (1+), moderate staining (2+), and strong staining (3+). The percentage was analyzed in 10 microscopic HPF. The proportion of nuclear positive cells was categorized as sporadic (positive cells < 10%); focal (positive cells > 11% and < 50%); and diffuse (positive cells ≥50%). The immunohistochemical scores of 2+ and 3+ with focal to diffuse distribution were considered to represent positive expression of p53, as described previously (Yonemori et al. 2006). Index texts analysis was performed—without knowledge of the diagnosis or clinical status—by two pathologists independently and, for discordant cases, a consensus diagnosis was achieved on a multi-head microscope.
Statistical analysis was carried out using the software SPSS for windows 21.0. Quantitative variables were described by mean and standard deviation or median and interquartile range. Categorical variables were described by absolute and relative frequencies. To compare means between degrees of tumor malignancy, the analysis of variance (ANOVA) plus the Tukey test were applied. In case of asymmetry, the Kruskal–Wallis test with the Dunn method was used. In comparing proportions, Pearson’s chi-squared test together with an adjusted residuals analysis was applied. To determine the best Ki-67 cutoff point for borderline or malignant PT, a receiver operating characteristic (ROC) curve was used. Diagnostic properties, such as sensitivity, specificity, positive and negative predictive values and accuracy, in addition to the kappa concordance coefficient, were calculated to aid in deciding the best combination of p53 and Ki-67 markers. A p-value below of 0.05 was considered a significant result.
The clinicopathologic characteristics are summarized in Table 1. The overall diagnostic agreement level was high, and all cases were considered to be originally correctly diagnosed as PT, and the agreement between grades was achieved in 92.5%. Briefly, the median age of patients with PT was 45 years (range: 16–74 years) and the association between age and benign, borderline, and malignant subgroups (see Table 2) was statistically significant (p < 0.001); as the patient’s age increases the degree of malignancy of the tumor increases. The median size of PT was 4.0 cm (range: 1–20 cm) and a positive association was established in the comparison of histological grades of PT with the tumor size (p = 0.005). Clinical outcome data was available in 68 cases (40 benign, 12 borderline and 16 malignant). All patients with benign PT were alive and disease-free at their last follow up visit. In borderline group we found 1 PT related death and 6 local recurrence. Death was associated with disease progression in 6 patients, and among 10 alive patients 5 had recurrence, in the malignant PT group.
Significance was observed in the expression of Ki-67 in the comparison of benign, borderline, and malignant PT with p < 0.001 being significantly lower in benign tumors when compared to borderline and malignant tumors, with no significant difference between them. The 10% cutoff point for Ki-67 best balanced sensitivity with specificity, with an area under the curve of 0.98 (95% confidence interval [CI]: 0.95–1), resulting in high specificity (96.4%), sensitivity (88.9%), and accuracy (94.5%) for borderline or malignant PTs with a very good concordance coefficient kappa of 0.85 (p < 0.001). For the analysis, if more than 10% of the total neoplastic cell nuclei stained, the case was considered positive. Of the benign tumors, 106 of 110 (96.4%) showed Ki-67 positivity ≤10% of the neoplastic cells, and all benign tumors showed Ki-67 expression lower than 20%. On the other hand, all 20 malignant PT showed Ki-67 positivity > 20% in the stromal neoplastic cells. In the borderline group, the Ki-67 was ≥20% in 12 cases, with the remaining 4 cases achieving a positivity range ≥ 10 and < 20%.
The study also showed a greater expression of p53 in malignant and borderline tumors when compared to benign PTs, and the p53 expression was significantly associated with grade (p < 0.001). The expression of p53 was considered to be positive in 28 (19.2%) of all 146 PTs. Only 5 of 110 (4.5%) benign PTs expressed p53 positivity; meanwhile, p53 positivity was achieved in 15 of 20 (75%) malignant PTs. The specificity of the p53 positivity to diagnose a borderline or malignant PT was 95.5%; the sensitivity was 63.9% and accuracy was 87.7%, with a good concordance coefficient kappa of 0.64 (p < 0.001).
When considering either of the positive tests for the diagnosis of a borderline or malignant PT (see Fig. 1 and Table 3), we achieved a sensitivity of 100%, a specificity of 91.8%, a positive predictive value (80%), a negative predictive value (100%), and an accuracy of 93.8%, with a very good concordance coefficient kappa of 0.85 (p < 0.001). When considering both positive tests—p53 positivity and Ki67 positivity (> 10%)—a diagnosis of malignant or borderline TP can be made with 100% specificity. However, the sensitivity is low (52.8%), the positive predictive value is 100%, the negative predictive value is 86.6%, and the accuracy is 88.4%, with a good concordance kappa of 0.63 (p < 0.001).
According to the WHO classification (Lakhani 2012), our cases reported as benign (75.5%), borderline (11%), and malignant (13.7%), are in accordance with published ranges of PT in the relevant series of other authors (Tan et al. 2016; Chang et al. 2018; Tan et al. 2005a; Efared et al. 2018; Jia et al. 2017; Spitaleri et al. 2013). An interesting study published in 2018 by Chang et al. analyzes the impact of the new WHO classification by retrospectively assessing 305 fibroepithelial lesions in the 2007–2017 period, and observing an increased diagnosis of benign PT, with a relative reduction in fibroadenoma diagnoses. The authors assume that this fact stems from the more methodical application of the morphological criteria described in the new classification (Chang et al. 2018).
The mean lesion size observed in this analysis, as well as the median and range, is also comparable to those reported in the literature (Tan et al. 2016; Tan et al. 2005a; Efared et al. 2018; Spitaleri et al. 2013). Although in this study series demonstrates a significant increase in the size of the lesions in relation to the degrees—a fact also observed in previous studies—the size of the lesion alone does not authorize the therapeutic decisions, according to Neville et al.’s study (Neville et al. 2018). The mean, median, and range of age of patients observed in this analysis are similar to those reported previously, as well as the significant association between age and degrees of PT (Lakhani 2012; Tan et al. 2005a; Jia et al. 2017; Spitaleri et al. 2013).
The differences in the clinical and pathological characteristics of PT reported by other authors are probably due to the inherent limitation of smaller series, as well as methodological aspects related to the recruitment of cases, or biases related to retrospective studies (Noronha et al. 2011; Kim et al. 2018; Piscuoglio et al. 2016; Sin et al. 2016).
PTs are biphasic neoplasms, but the stromal element is regarded as the neoplastic component and, consequently, as the determinant of clinical behavior (Tan et al. 2016; Feakins et al. 1999). Nevertheless, many authors describe immunohistochemical patterns of epithelial positivity as being indicative of p53 positivity (Tan et al. 2005b; Kim and Kim 1993; Munawer et al. 2012). Moreover, the scores used to evaluate the presence of positivity for p53 are quite varied when quantifying expression and intensity of the reaction, and in some studies the positivity criterion is not even detailed (Mishra et al. 2013; Wang et al. 2017). The strong relation between immunohistochemical expression of p53 and malignant PT had already been observed by Kim and Kim in 1993, in the first report in the literature on this subject (Kim and Kim 1993). Since then, studies evaluating p53 expression in PT have been few in the literature, with most of them including only a limited number of cases. The largest published series on PT originated from a single institution, where Tan et al. analyzed the prognostic role of morphological parameters in 355 Asian women diagnosed with PT (Tan et al. 2005b), authors considered epithelial and stromal positivity, and any percentage of expression or intensity of reaction, as a positive result for p53, without determination of a cutoff for the index test. Although counting on a series of only 15 PTs (6 malignant, 9 benign) and 20 fibroadenomas, Millar et al. suggest that not only the positivity itself but also the expression pattern of p53 and the intensity of the reaction are of diagnostic value for PT (Millar et al. 1999). The same impression was shared by Niezabitowski et al. Two years later, when they stated that expression of the p53 in tumor cells also could be useful as a predictive indicator when the number of cells and the intensity of expression are considered (Niezabitowski et al. 2001). Similarly, when analyzing 143 cases of PT (87 benign, 37 borderline, and 19 malignant), Tse et al. stated that the strong and diffuse pattern of p53 presents high specificity (99%) but low sensitivity (47%) for the diagnosis of malignant PT (Tse et al. 2002). However, this pattern was only observed in one (3%) borderline PT in this series, which limits its practical use since these tumors have biological behavior and consequent surgical management similar to malignant ones. When compared to our findings, the specificity (95.5%) and sensitivity (63.9%) values are similar. However, in our series this association was observed in the group that includes malignant and borderline PTs, which makes the finding more significant with implications for the practice and intended use of the index test. We believe that the difference is due to the nature of the score used to establish the positivity of the index test. When studying 63 PTs (50 benign and 13 malignant), Chan et al. found similar results (Chan et al. 2004). An interesting aspect of their study was—in the absence of generalized accepted standard percentage to define high expression—with different authors applying different cutoff levels from 5 to 34% (Kim and Kim 1993; Feakins et al. 1999; Gatalica et al. 2001; Niezabitowski et al. 2001; Millar et al. 1999; Kocova et al. 1998), Chan proposed a new score (0–10%, 11–30%, 31–50%, and 51–100%). However, their study did not take into account the intensity of the reaction in the evaluation, nor did it define what should be considered a positive result for the index test based on the analysis of the scores (Chan et al. 2004). One of the few studies that correlated p53 expression with systemic recurrence and survival in PT, adopted the intensity of the immunohistochemical staining and the proportion of positive cells, which were categorized as sporadic, focal, and diffuse (Yonemori et al. 2006). This score has been used in our study and is described in detail above.
Although there is a growing body of evidence for the utility of Ki-67 for predicting clinical prognosis in many different tumor entities, reports failed to demonstrate an association in PT cases (Kocova et al. 1998). The likely reasons are the same for p53: associated with a small series and short follow-up. Umekita and Yoshida were the first to correlate Ki-67 with the histological grade of malignancy in PT, using a grading histopathological system similar to the current WHO classification. Applying a 10% cutoff for positivity, but considering stromal and epithelial cells for analysis, they correlated Ki-67 with a histological grade of malignancy (Umekita and Yoshida 1999). When analyzing 52 benign PTs, 24 borderline PTs, and 42 malignant PTs, Niezabitowski et al. found a correlation between the expression of Ki-67 and prognostic factors among patients with malignant PT, and with histological grading (Niezabitowski et al. 2001). However, the cutoff used in the analyses—defined as 11.2% and derived from a previous study on cutaneous melanomas—is difficult to apply in practice. The same cutoff was used later and also showed a correlation with prognostic factors (Yonemori et al. 2006). Although almost all authors have been correlating Ki-67 expression with morphologic grading, increasing from benign, borderline, to malignant PTs, labelling indices have been reported to range from 1.3 to 50%. Also, there is no generally accepted standard percentage that defines a positive result, with different authors applying different cutoff levels from 5 to 20% (Yonemori et al. 2006; Umekita and Yoshida 1999; Chan et al. 2004; Niezabitowski et al. 2001; Jara-Lazaro et al. 2010). Furthermore, many reports have not used any cutoff to define a positive index test (Yonemori et al. 2006; Tan and Tan 2018; Umekita and Yoshida 1999; Chan et al. 2004; Niezabitowski et al. 2001; Jara-Lazaro et al. 2010).
Our study has some limitations. We performed all analyses on surgical specimens, so we cannot extend the application of our findings to core biopsy samples. A similar study design focused on biopsy specimens could clear this restriction. Alternatively, a tissue microarray (TMA) could be constructed with random samples and then the results correlated. The TMA technique can be effectively applied in PTs to study immunohistochemical markers, according to Tan et al. and Munawer et al. (Tan et al. 2005b; Munawer et al. 2012).
Our experiment provides a practical methodology to achieve a highly accurate grading of PT, benign versus borderline/malignant, compared to gold standard, based on clearly defined and easy to apply cutoffs of a simple immunohistochemical panel of Ki-67 and p53. When considering either of the positive tests for the diagnosis of a borderline or malignant PT, we achieved a sensitivity of 100% with a specificity of 91.8%. In conclusion, a PT positive for either of index tests should be graded as borderline or malignant. We hope this new approach might provide a basis for the development of standardization in the use of p53 and Ki-67 for grading PTs.
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Analysis of variance
High power fields
Receiver operating characteristic
Appel ML, Edelweiss MI, Fleck J, Rivero LF, Rivoire WA, Monego HI et al (2008) P53 and BCL-2 as prognostic markers in endometrial carcinoma. Pathol Oncol Res 14(1):23–30
Birch JM, Alston RD, McNally RJ, Evans DG, Kelsey AM, Harris M et al (2001) Relative frequency and morphology of cancers in carriers of germline TP53 mutations. Oncogene. 20(34):4621–4628
Bossuyt PM, Reitsma JB, Bruns DE, Gatsonis CA, Glasziou PP, Irwig L et al (2015) STARD 2015: an updated list of essential items for reporting diagnostic accuracy studies. Radiology. 277(3):826–832
Chan YJ, Chen BF, Chang CL, Yang TL, Fan CC (2004) Expression of p53 protein and Ki-67 antigen in phyllodes tumor of the breast. J Chin Med Assoc 67(1):3–8
Chang J, Denham L, Dong EK, Malek K, Lum SS (2018) Trends in the DiagnosisB1 of Phyllodes Tumors and Fibroadenomas Before and After Release of WHO Classification Standards. Ann Surg Oncol. 2018;25(10):3088–95.
Chng TW, Gudi M, Lim SH, Li H, Tan PH (2018) Validation of the Singapore nomogram for outcome prediction in breast phyllodes tumours in a large patient cohort. J Clin Pathol 71(2):125–128
Dowsett M, Nielsen TO, A'Hern R, Bartlett J, Coombes RC, Cuzick J et al (2011) Assessment of Ki67 in breast cancer: recommendations from the international Ki67 in breast Cancer working group. J Natl Cancer Inst 103(22):1656–1664
Efared B, Ebang GA, Tahiri L, Sidibe IS, Erregad F, Hammas N et al (2018) Phyllodes tumors of the breast: clinicopathological analysis of 106 cases from a single institution. Breast Dis 37(3):139–145
Feakins RM, Mulcahy HE, Nickols CD, Wells CA (1999) p53 expression in phyllodes tumours is associated with histological features of malignancy but does not predict outcome. Histopathology. 35(2):162–169
Gatalica Z, Finkelstein S, Lucio E, Tawfik O, Palazzo J, Hightower B et al (2001) p53 protein expression and gene mutation in phyllodes tumors of the breast. Pathol Res Pract 197(3):183–187
Giacomazzi J, Koehler-Santos P, Palmero EI, Graudenz MS, Rivero LF, Lima E et al (2013) A TP53 founder mutation, p.R337H, is associated with phyllodes breast tumors in Brazil. Virchows Arch 463(1):17–22
Hanahan D, Weinberg RA (2000) The hallmarks of cancer. Cell. 100(1):57–70
Jacobs TW, Chen YY, Guinee DG Jr, Holden JA, Cha I, Bauermeister DE et al (2005) Fibroepithelial lesions with cellular stroma on breast core needle biopsy: are there predictors of outcome on surgical excision? Am J Clin Pathol 124(3):342–354
Jara-Lazaro AR, Akhilesh M, Thike AA, Lui PC, Tse GM, Tan PH (2010) Predictors of phyllodes tumours on core biopsy specimens of fibroepithelial neoplasms. Histopathology. 57(2):220–232
Jia C, Mei F, Liu JY, Zhao HM, Lei YT, Su J et al (2017) Histologic classification and prognosis factors in phyllodes tumors of breast. Zhonghua Bing Li Xue Za Zhi 46(1):14–19
Kawai A, Noguchi M, Beppu Y, Yokoyama R, Mukai K, Hirohashi S et al (1994) Nuclear immunoreaction of p53 protein in soft tissue sarcomas. A possible prognostic factor. Cancer. 73(10):2499–2505
Khazai L, Middleton LP, Goktepe N, Liu BT, Sahin AA (2015) Breast pathology second review identifies clinically significant discrepancies in over 10% of patients. J Surg Oncol 111(2):192–197
Kim CJ, Kim WH (1993) Patterns of p53 expression in phyllodes tumors of the breast--an immunohistochemical study. J Korean Med Sci 8(5):325–328
Kim JY, Yu JH, Nam SJ, Kim SW, Lee SK, Park WY et al (2018) Genetic and clinical characteristics of Phyllodes tumors of the breast. Transl Oncol 11(1):18–23
Kocova L, Skalova A, Fakan F, Rousarova M (1998) Phyllodes tumour of the breast: immunohistochemical study of 37 tumours using MIB1 antibody. Pathol Res Pract 194(2):97–104
Korcheva VB, Levine J, Beadling C, Warrick A, Countryman G, Olson NR et al (2011) Immunohistochemical and molecular markers in breast phyllodes tumors. Appl Immunohistochem Mol Morphol 19(2):119–125
Kucuk U, Bayol U, Pala EE, Cumurcu S (2013) Importance of P53, Ki-67 expression in the differential diagnosis of benign/malignant phyllodes tumors of the breast. Indian J Pathol Microbiol 56(2):129–134
Lae M, Vincent-Salomon A, Savignoni A, Huon I, Freneaux P, Sigal-Zafrani B et al (2007) Phyllodes tumors of the breast segregate in two groups according to genetic criteria. Mod Pathol 20(4):435–444
Lakhani SR (2012) WHO classification of tumours of the breast. World Health Organization classification of tumours. In: International Agency for Research on Cancer, 4th edn, p 1
Lawton TJ, Acs G, Argani P, Farshid G, Gilcrease M, Goldstein N et al (2014) Interobserver variability by pathologists in the distinction between cellular fibroadenomas and phyllodes tumors. Int J Surg Pathol 22(8):695–698
Lin CK, Tsai WC, Lin YC, Yu JC (2014) Biomarkers distinguishing mammary fibroepithelial neoplasms: a tissue microarray study. Appl Immunohistochem Mol Morphol 22(6):433–441
Mastellaro MJ, Seidinger AL, Kang G, Abrahao R, Miranda ECM, Pounds SB et al (2017) Contribution of the TP53 R337H mutation to the cancer burden in southern Brazil: insights from the study of 55 families of children with adrenocortical tumors. Cancer. 123(16):3150–3158
Millar EK, Beretov J, Marr P, Sarris M, Clarke RA, Kearsley JH et al (1999) Malignant phyllodes tumours of the breast display increased stromal p53 protein expression. Histopathology. 34(6):491–496
Mishra SP, Tiwary SK, Mishra M, Khanna AK (2013) Phyllodes tumor of breast: a review article. ISRN Surg 2013:361469
Munawer NH, Md Zin R, Md Ali SA, Muhammad R, Ali J, Das S (2012) ER, p53 and MIB-1 are significantly associated with malignant phyllodes tumor. Biom J 35(6):486–492
Murnyak B, Hortobagyi T (2016) Immunohistochemical correlates of TP53 somatic mutations in cancer. Oncotarget. 7(40):64910–64920
Neville G, Neill CO, Murphy R, Corrigan M, Redmond PH, Feeley L, et al. Is excision biopsy of fibroadenomas based solely on size criteria warranted? Breast J. 2018
Niezabitowski A, Lackowska B, Rys J, Kruczak A, Kowalska T, Mitus J et al (2001) Prognostic evaluation of proliferative activity and DNA content in the phyllodes tumor of the breast: immunohistochemical and flow cytometric study of 118 cases. Breast Cancer Res Treat 65(1):77–85
Noronha Y, Raza A, Hutchins B, Chase D, Garberoglio C, Chu P et al (2011) CD34, CD117, and Ki-67 expression in phyllodes tumor of the breast: an immunohistochemical study of 33 cases. Int J Surg Pathol 19(2):152–158
Pareja F, Geyer FC, Kumar R, Selenica P, Piscuoglio S, Ng CKY et al (2017) Phyllodes tumors with and without fibroadenoma-like areas display distinct genomic features and may evolve through distinct pathways. NPJ Breast Cancer 3:40
Piscuoglio S, Ng CK, Murray M, Burke KA, Edelweiss M, Geyer FC et al (2016) Massively parallel sequencing of phyllodes tumours of the breast reveals actionable mutations, and TERT promoter hotspot mutations and TERT gene amplification as likely drivers of progression. J Pathol 238(4):508–518
Pornchai S, Chirappapha P, Pipatsakulroj W, Lertsithichai P, Vassanasiri W, Sitathanee C et al (2018) Malignant transformation of phyllodes tumor: a case report and review of literature. Clin Case Rep 6(4):678–685
Rakha EA, Ahmed MA, Aleskandarany MA, Hodi Z, Lee AH, Pinder SE et al (2017) Diagnostic concordance of breast pathologists: lessons from the National Health Service Breast Screening Programme Pathology External Quality Assurance Scheme. Histopathology. 70(4):632–642
Rivlin N, Brosh R, Oren M, Rotter V (2011) Mutations in the p53 tumor suppressor gene: important milestones at the various steps of tumorigenesis. Genes Cancer 2(4):466–474
Shaaban M, Barthelmes L (2017) Benign phyllodes tumours of the breast: (over) treatment of margins - a literature review. Eur J Surg Oncol 43(7):1186–1190
Sin EI, Wong CY, Yong WS, Ong KW, Madhukumar P, Tan VK et al (2016) Breast carcinoma and phyllodes tumour: a case series. J Clin Pathol 69(4):364–369
Spitaleri G, Toesca A, Botteri E, Bottiglieri L, Rotmensz N, Boselli S et al (2013) Breast phyllodes tumor: a review of literature and a single center retrospective series analysis. Crit Rev Oncol Hematol 88(2):427–436
Tan BY, Acs G, Apple SK, Badve S, Bleiweiss IJ, Brogi E et al (2016) Phyllodes tumours of the breast: a consensus review. Histopathology. 68(1):5–21
Tan BY, Tan PH (2018) A diagnostic approach to Fibroepithelial breast lesions. Surg Pathol Clin 11(1):17–42
Tan PH, Bay BH, Yip G, Selvarajan S, Tan P, Wu J et al (2005c) Immunohistochemical detection of Ki67 in breast cancer correlates with transcriptional regulation of genes related to apoptosis and cell death. Mod Pathol 18(3):374–381
Tan PH, Jayabaskar T, Chuah KL, Lee HY, Tan Y, Hilmy M et al (2005a) Phyllodes tumors of the breast: the role of pathologic parameters. Am J Clin Pathol 123(4):529–540
Tan PH, Jayabaskar T, Yip G, Tan Y, Hilmy M, Selvarajan S et al (2005b) p53 and c-kit (CD117) protein expression as prognostic indicators in breast phyllodes tumors: a tissue microarray study. Mod Pathol 18(12):1527–1534
Tan PH, Thike AA, Tan WJ, Thu MM, Busmanis I, Li H et al (2012) Predicting clinical behaviour of breast phyllodes tumours: a nomogram based on histological criteria and surgical margins. J Clin Pathol 65(1):69–76
Tremblay-LeMay R, Hogue JC, Provencher L, Poirier B, Poirier E, Laberge S et al (2017) How wide should margins be for Phyllodes tumors of the breast? Breast J 23(3):315–322
Tse GM, Putti TC, Kung FY, Scolyer RA, Law BK, Lau TS et al (2002) Increased p53 protein expression in malignant mammary phyllodes tumors. Mod Pathol 15(7):734–740
Umekita Y, Yoshida H (1999) Immunohistochemical study of MIB1 expression in phyllodes tumor and fibroadenoma. Pathol Int 49(9):807–810
Vidal M, Peg V, Galvan P, Tres A, Cortes J, Ramon Y, Cajal S et al (2015) Gene expression-based classifications of fibroadenomas and phyllodes tumours of the breast. Mol Oncol 9(6):1081–1090
Vilela MH, de Almeida FM, de Paula GM, Ribeiro NB, Cirqueira MB, Silva AL et al (2014) Utility of Ki-67, CD10, CD34, p53, CD117, and mast cell content in the differential diagnosis of cellular fibroadenomas and in the classification of phyllodes tumors of the breast. Int J Surg Pathol 22(6):485–491
Wang Y, Zhu J, Gou J, Xiong J, Yang X (2017) Phyllodes tumors of the breast in 2 sisters: case report and review of literature. Medicine (Baltimore) 96(46):e8552
Yemelyanova A, Vang R, Kshirsagar M, Lu D, Marks MA, Shih Ie M et al (2011) Immunohistochemical staining patterns of p53 can serve as a surrogate marker for TP53 mutations in ovarian carcinoma: an immunohistochemical and nucleotide sequencing analysis. Mod Pathol 24(9):1248–1253
Yonemori K, Hasegawa T, Shimizu C, Shibata T, Matsumoto K, Kouno T et al (2006) Correlation of p53 and MIB-1 expression with both the systemic recurrence and survival in cases of phyllodes tumors of the breast. Pathol Res Pract 202(10):705–712
Zlobec I, Steele R, Michel RP, Compton CC, Lugli A, Jass JR (2006) Scoring of p53, VEGF, Bcl-2 and APAF-1 immunohistochemistry and interobserver reliability in colorectal cancer. Mod Pathol 19(9):1236–1242
We gratefully acknowledge the staff members of Patology laboratory for their help and cooperation.
FIPE from Hospital de Clínicas de Porto Alegre for financial support for carrying out the immunohistochemical tests.
Ethics approval and consent to participate
Ethics committee of Hospital de Clínicas de Porto Alegre approved the study. CAAE: 50732315.5.0000.5327.
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The authors declare that they have no competing interests.
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Rivero, L.F., Graudenz, M.S., Aschton-Prolla, P. et al. Accuracy of p53 and ki-67 in the graduation of phyllodes tumor, a model for practical application. Surg Exp Pathol 3, 7 (2020). https://doi.org/10.1186/s42047-020-0058-3