Discordance of estrogen and progesterone receptors after neoadjuvant chemotherapy in locally advanced breast cancer.

Aims and objective: This study aimed to compare hormone receptor (HR) status before and after neoadjuvant chemotherapy that is discordance in locally advanced breast cancer patients, which are amenable for surgery. The secondary objective was to study the correlation between tumor response and HR expression.

Materials and methods: The duration of the study was from August 2018 to December 2020. A total of 23 patients were selected as per certain inclusion criteria. American Society of Clinical Oncologys methodology was used to analyze estrogen receptor (ER) and progesterone receptor (PR) status of histopathology specimen. For study purposes, patients were classified into four groups after core biopsy of breast lump and after definitive surgery (post-NACT (neoadjuvant chemotherapy)) - Group A (ER+, PR+), Group B (ER+, PR-), Group C (ER-, PR+), and Group D (ER-, PR-).

Results: ER discordance was found to be (2/23) 8.69% (P value 0.76). PR discordance was (4/23) 17.39%. PR discordance was found to be higher than ER discordance. Changes in staining patterns in ERs were seen in 14 patients (93.33%). Changes in staining percentage in PRs were seen in eight patients (80%). It was found that both receptor-positive and negative diseases had an equal proportion of stable disease.

Conclusion: From the study, it is noted that performing ER PR study twice (before and after chemotherapy) is necessary as discordance is noted and this may impact the further treatment strategy.