Fig. 4

Two cases of invasive ductal carcinoma of the breast. Images a and c show, respectively, two-photon-excited fluorescence microscopy (TPEF) and second harmonic generation (SHG) of a patient (P1) who presented disease progression (metastasis/recurrence). b and d show, respectively, TPEF and SHG of a patient (P2) whose disease did not progress. In graphs E and F, the black line corresponds to patient P1 and the red line to patient P2. Notice that in graph e collagen fibers are arranged between − 70° to − 20° (variation of 50°) for patient P1 and between − 50° to 60° (variation of 110°) for patient P2. In graph f it is shown that patient P1 had total amount of collagen fibers greater than patient P2. This is in line with previous evidence that intratumoral collagen with less angulation, that is, more organized, and that greater amounts of intratumoral collagen are associated with higher risk of disease progression