Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are therapeutically as well as prognostically important. The discordance of ER, PR, and HER2 between primary and the recurrent breast cancer has been recognized in studies with few reporting change in therapy as well. However, many still use report of primary tumor to guide treatment in the recurrent setting and FNA is a routine to label a lesion metastasis without knowing the IHC before starting further treatment.
This was an observational study carried out from September 2015 to February 2017. All recurrent (locoregional or metastatic) breast cancer patients were analyzed. Biopsy was done from the recurrent site and IHC study was performed. The discordance of ER, PR and HER2 status between primary tumor and recurrent disease were analyzed. Mc Nemar test on SPSS version 23.0 was used to see the statistical significance.
A total of 78 patients were analyzed. Thirty five (45%) patients had only locoregional, 14 (18%) had only visceral and 29 (37%) had locoregional alongwith visceral metastasis at recurrence. The discordance rate for ER was 13.7% (n = 11; p=.227). Among these, 3 (3.7%) had ER changed from positive to negative whereas 8 (10%) had change from negative to positive. The discordance rate for PR was higher with 28.7% (n = 23; p=.017). Those who had receptor changed from positive to negative was 6 (7.5%) while 17 (21.2%) had change from negative to positive. The discordance of HER2 was seen in 21.2% (n = 17; p=.013) with 3 (3.7%) showing change from positive to negative and 14 (17.5%) from negative to positive. Overall, a higher number of patients had receptor negative in primary to receptor positive in the recurrent specimen than converting from positive to negative This led to a newer treatment option in 31% of patients.
Routine biopsy and analyses for ER, PR, and HER2 status in the recurrent setting should be done in all patients, which have important implications in the management as well as prognosis.
Clinical trial identification
Legal entity responsible for the study
Kidwai Cancer Institute, Bangalore.
Has not received any funding.
All authors have declared no conflicts of interest.