Response to neoadjuvant therapy in breast cancer: tumour regression and lymph node status

Abstract

BACKGROUND: Neoadjuvant therapy (NAT) prior to mastectomy is used to treat locally advanced breast carcinoma. This study assessed the response of breast cancer patients to NAT. METHODS: In a prospective study on 17 patients with carcinoma of the breast (16 females; age range 34—71 years) subjected to NAT prior to mastectomy, reduction in tumour size and the residual microscopic tumour percentage graded as, 0% - complete regression, 1-19% - marked regression, 20-79% - moderate regression, 80-99% - minimal regression, 100% - no regression, was assessed. Number of lymph nodes harvested and the number containing metastases (positivity) was compared with a control group of breast cancer patients (age and stage matched) undergoing mastectomy without NAT from a unit with a different treatment policy. RESULTS: Tumour size before NAT (mean 4.1cms) compared with that after NAT (mean l.Scms) was statistically significant (p<0.05). Microscopic assessment of residual tumour percentage showed 4 (23.5%) with complete regression, 2 (11.9%) with marked regression, 4 (23.5%) with moderate regression, 6 (35%) with minimum regression and 1 (5.8) with no regression. Neither the mean lymph node harvest of 11 (range 6-20) nor the mean lymph node positivity of 1.7 (range 0-8) in the NAT group were significantly different from values obtained for the control group [mean lymph node harvest 9.7 (range 4-18); mean lymph node positivity 2 (range 0-8)] (p>0.05). CONCLUSIONS: NAT causes macroscopic and microscopic reduction in tumour size in breast cancer. However, there is no significant difference on the therapeutic effect on axillary lymph nodes between patients receiving NAT and those undergoing mastectomy alone.