Frequency of axillary nodal complete pathological response of breast cancer patients in neoadjuvant chemotherapy setting: A cross-sectional study.

Objectives: Pathological complete response (pCR) occurs in about 20-30% of patients undergoing systemic neoadjuvant therapy. This leads to the idea of sparing the patient the morbidity associated with axillary surgery. "Wait and watch" policy for cancers which achieve complete pathological response on neoadjuvant systemic therapy is a well-established practice in various cancers like the esophagus, rectum and larynx. This has led to organ preservation protocols being practiced worldwide for these cancers without affecting the overall survival of the patient. We believe patients undergoing a complete pathological response in the breast may be spared axillary surgery. Axillary surgery leads to morbidity and extra financial burden with no added advantage in survival.

Material and methods: A total of 326 patients with breast cancer who had received neoadjuvant systemic chemotherapy from 2015 to 2020 were included in our retrospective study. Final histopathology of the breast and axillary surgery was noted to report the frequency of complete pathological response. The frequency of positive nodal disease with respect to stage, grade and type of cancer was measured.

Results: Among 326 patients, our study showed that 53% of patients with complete pathological response in breast also had complete response in the axilla compared to 43% with incomplete pathological response. No significant difference was found for age, menopausal status, initial tumor size when patients with complete pathological response were compared to non or partial responders. The rate of complete pathological response was higher in patients with clinically node negative patients after NACT, hormone negative, HER2 positive and triple negative population.

Conclusion: Our results indicated that 53% of the patients who developed complete pathological response in the breast underwent needless axillary procedure. Axillary surgery can be staged after the breast surgery if residual tumor is present on the histopathological specimen. In case of pCR, omission of axillary surgery can be considered. However, a larger population, multi-centric studies are needed for treatment guidelines.