PGR and cancer: In the 340 female cats with invasive mammary carcinomas, the risk of cancer-related death was predicted by 3 independent prognostic factors by multivariate analysis (p < 0.0001; Table 5): the histological stage (HR = 2.72 for stage IIIB, HR = 1.76 for Stage IIIA compared to stage I), PR expression (HR = 0.34 for PR+ FMCs compared to PR–), and tumor-associated inflammation (HR = 1.33 when moderate to severe compared to absent to mild).