Case control study of novel prognostic markers and disease outcome in pregnancy/lactation-associated breast carcinoma

A case control study of pregnancy/lactation associated breast carcinoma (PAC) was conducted on 24 test cases with two controls per case, matching age, tumor grade, tumor size and axillary lymph nodes status. During seven years of this study, 6% of all patients with breast cancer had PAC. In this study, 67% of the test cases showed positive axillary lymph nodes compared to 49% in our series of 315 cases of non-pregnancy/non-lactating women with breast carcinoma (p < 0.05). The expression of nine prognostic markers, i.e. ER, PR, p53, C-erbB-2, EGFR, Cathepsin-D, PCNA, DNA ploidy and S-phase fraction, were studied by immunohistochemistry and flow cytometry. Hormone receptor status showed a statistically significant difference between the two groups, i.e. 29% immunoreactivity in test cases compared to 58% in controls with a p value of 0.007. Among p53, C-erbB-2, EGFR and Cathepsin-D in the test group, only EGFR showed a significant correlation, i.e. 33% immunoreactivity in test cases and 19% immunoreactivity in controls (p < 0.05). Higher PCNA positivity was seen in the test group compared to controls, i.e. 35% in test patients and 28% in controls (p < 0.05). Metastasis to bone and liver was a common feature of test patients as compared to controls (p < 0.05). After a median follow-up of 72 months, there was no significant difference in the overall survival (OS) of test cases and controls as 54% deaths were recorded in test patients and 44% in controls at the end of this study (p > 0.05). In summary, in spite of some significant differences in the expression of few prognostic markers, i.e. ER/PR, EGFR, PCNA and metastatic potential, there was no significant difference in the OS of PAC vs. control group if compared stage for stage.