Fig. 3

A specific subset of CAF is associated with distant recurrence in luminal breast cancer. a Representative views of SMA, FAP, CD29, PDGFR-β, and FSP1 immunostaining in cases and controls (scale bar = 50 μm). b–f Boxplots showing histological scores (H scores) for CAF markers (SMA, FAP, CD29, PDGFR-β, and FSP1) according to recurrence status and molecular subtype (N = 104, 52 controls, 52 cases). H scores are given as a function of percentage of stained CAF multiplied by its respective staining intensity (ranging from 0 to 3). p values are from Wilcoxon tests. Boxplots color code is indicated below b–f. It indicates the BC subtype d by Prosigna™ test. Luminal A BC are in light blue (controls, N = 37) and light red (cases, N = 27). Luminal B BC are in dark blue (controls, N = 11) and dark red (cases, N = 19). HER2-enriched BC are in light green (controls, N = 2) and dark green (cases, N = 2). Basal-like BC are in yellow. BC without result by Prosigna™ test are in gray (2 controls and 3 cases). g Decision tree used to define CAF subset identity according to CAF maker intensities, based on 4 equal quartiles (Q1-Q4) and median (med) distribution of each CAF marker, as shown in [22]. h, i Bar plot showing the distribution of CAF subset enrichment in luminal early BC for all patients (h) and according to the recurrence status (i). For each BC analyzed, enrichment is defined by applying H scores of all markers on the decision tree described in g. Breast cancer enriched in CAF-S1 (red), CAF-S2 (orange), CAF-S3 (green), or CAF-S4 (blue) are shown as percentage (%) (N = 104, 52 controls, 52 cases). p value is from Fisher exact test. j Contingency table for the repartition of CAF subsets enrichment according to the recurrence status (N = 104, 52 controls, 52 cases). p values are from Fisher exact test. k Representative views of maps of CAF subsets at cellular scale using the decision tree algorithm (shown in g) and CAF marker histological scoring on serial BC sections (corresponding sections and staining shown Additional File 6: Fig. S4). CAF-S1 are in red, CAF-S2 in orange, CAF-S3 in green, and CAF-S4 in blue. Scale bar, 100 μm. l Left, Kaplan-Meier survival analysis for distant recurrence rate according to low- and high-FAP H scores. Patient subgroups defined by median. p value is from Log-Rank test. Right, same as in left with patients stratified in 3 categories according to FAP H scores: low-FAP if H score ≤ 47 (N = 52), intermediate-FAP if H score > 47 and ≤ 95 (N = 26), and high-FAP if H score > 95 (N = 26). p value is from Log-Rank test