Biopathologic profile of breast cancer core biopsy: is it always a valid method?

For breast cancer management biopathologic profile and particularly the expression of estrogen receptor (ER) and progesterone receptor (PR) is considered essential. In advanced cases, core biopsy results are the only data available. To evaluate reliability of data, results of ER, PR, MIB1, p53 and c-erbB2 on core biopsy were compared with those on surgical specimens. Results showed a statistically significant concordance for ER and PR in pT1 but not in pT2 tumors, possibly due to breast cancer heterogeneity. MIB1 results were worse with no significant concordance even for pT1 group. There was statistically significant concordance in pT1 and pT2 groups for p53 and c-erbB 2, probably due to the high number of negative cases for these markers. We recommend more core biopsies for larger tumors since core biopsy has a high probability for giving unreliable data in these cases. In conclusion, this study showed that core biopsy has a high probability for not very reliable data in bigger tumors where the results obtained might be the only data available. A higher number of core biopsy is recommended in those cases.