Re-biopsy in breast cancer recurrence: Is there really a clinical impact?

Abstract

e11549 Background: Several retrospective studies and 3 prospective studies have shown discordance in receptor status between primary tumor and metastasis leading to a treatment modification in about one out of 7 patients. However, some clinicians report unpublished data suggesting that these findings are not observed in all centers. We did prospectively a biopsy at suspicion of first relapse in our center and evaluated the impact of this biopsy on the management of our patients. Methods: Thirty four patients underwent a biopsy between October 2011 and January 2013. Hormonal receptor status was determined by the same IHC methodology for primary and metastatic tissue. Primary tumors were reanalyzed if necessary with our current IHC technique. A change in ER or PgR status was considered clinically significant if quantitative staining changed from <5 % to at least 10% of tumor cells expressing the hormonal receptor or if the opposite is observed. We tested HER2 status by IHC and/or FISH: HER2 3+ or 2+ and FISH positive cases were considered as HER2 positive. Results: Three of 34 patients were considered as screening failure. 1/31 (3.2 %) biopsies showed a benign disease, 2/31 (6.4 %) were non contributive and 5/31 (16 %) showed a metastasis of a second primary tumor. Two of these findings were totally unexpected according to clinical data. Changes in hormone receptor status were observed in 25 % but no change in HER2 status was observed. Time to recurrence was not significantly different between groups with or without modified hormonal status. No clinically significant complication was observed following the biopsies. Only patients presenting a second primary tumor had their management changed based on the new biopsy. Conclusions: We found discordance in hormone receptor status (25 %) but it did not change the treatment. Our study confirms the importance of re-biopsy in order to exclude benign disease or to find metastasis from an unknown and sometimes unexpected second primary tumor. Although our study does neither confirm changes in hormonal receptors resulting in the modification of the treatment strategy nor a change in HER2 status, our data suggest that a new biopsy at first relapse should be performed because unexpected second primaries can be discovered.