GPPO21: A single Institutional Prospective Study on ER, PR, Her 2 neu, Ki67 Expression and Discordance Pattern in Primary and Metastatic and Recurrent Carcinoma Breast and its Therapeutic Implication and Prognostic Outcome.
CONSULTANT SURGICAL ONCOLOGIST NIMS MEDICTY Thiruvananthapuram, Kerala, India
Introduction: Only few studies reported in literature, that has elucidated in detail, the implications of molecular typing in metastatic and recurrent breast cancer and almost nil or just a few. In this prospective study we have analysed in depth, the pattern of expression, discordances of molecular markers in various metastatic sites and recurrent cases and their response to chemotherapy/targeted agents and the prognostic outcome
Methods: Prospective open label study done at Government Rajaji Hospital, Madurai Medical College August 2015 to August 2021. All breast carcinoma patients with recurrence or oligo metastasis (defined as one organ with less than 5 metastases in our study) with known receptor status were eligible and 110 patients were enrolled in the study.
Results: ER (ER+ to ER -) discordance was seen in 19 (26.38%) cases. PR (PR+ to PR –Ve) discordance was seen in 14 (19.17%) cases. HER 2 NEU (HER 2 NEU +Ve to –Ve) discordance was seen in 3 (16.6%) cases. Ki67 discordance was seen in 54 (49.09%) cases. High ki67 as a proliferative marker has increased response to chemotherapy but earlier relapse and disease progression especially in Luminal B type. In further subset analysis, ER, PR, HER 2 NEU discordance is higher for lung metastasis (ER, PR 61.1%, p value .001, HER 2 NEU 5.5%), followed by liver metastasis (ER, PR 50%, p value .0023, 1 case turning ER -ve to +ve, HER 2 NEU 1(10%). In lung, discordance is more for metachronous metastasis. In liver discordance is 100% for synchronous metastasis. Synchronous metastasis with discordance in ER, PR is associated with rapid disease progression. High KI 67 subset of Luminal B like tumors progressed rapidly than triple negative and HER 2 NEU positive subset. Complete clinical response rate in contralateral axillary node metastasis group was 87.8%, followed by local only recurrence with high Ki 67 where chemotherapy had response rate of 81% and 2 years DFS of 93.12% after excision.
Conclusions: Certain subsets like contralateral axillary nodes, supraclavicular nodes which present as oligo metastatic disease with discordance and high Ki 67 respond well to chemotherapeutics and targeted agents improving the OS in these subset of patients. Molecular markers and their expression and discordance pattern determines the therapeutic outcome and prognosis of the disease. Early identification and targeting the discordance would go a long way in improving the outcome and DFS, OS of breast cancer patients.