Biological and clinical relevance of proliferative activity in inflammatory breast cancer

The hormone receptor status and proliferative activity characteristics of inflammatory breast cancer (IBC) were studied in a series of 46 patients. ER and PgR were measured by the DCC method and proliferative activity was by the ³H-thymidine autoradiographic labeling index (³H-Tdr-LI). Tumors were ER and PgR positive in 42% and 38% of cases, respectively, whereas median ³H-Tdr-LI was 3.8%. With regard to clinical aspects, overall survival (OS) was not affected by either ER status (36 cases) or ³H-Tdr-LI value (33 cases). On the contrary, PgR⁺ status was able to individualize women with a significantly higher probability of OS (X² by long rank test, p = 0.03) after 35 months of follow-up. In the subgroup of 14 patients subjected to double biopsy performed before and after administration of primary polychemotherapy, the tumor proliferative activity variations were not related to clinical outcome.