Evaluation of Tumor Elasticity and Clinicopathologic Factors Affecting Neoadjuvant Chemotherapy Response in Patients with Breast Cancer

ABSTRACT

Purpose@#This study aimed to determine the clinicopathologic factors, including tumor elasticity, affecting neoadjuvant chemotherapy response in breast cancer. @*Methods@#Among 95 patients who received neoadjuvant chemotherapy for clinical stage IIa-IIIc primary breast cancer, 75 underwent strain elastography assessments. The patients were divided into soft and hard tumor groups based on the Tsukuba elasticity scoring system. Pathologic factors, including tumor cellularity and stromal characteristics, were evaluated using core needle biopsy specimens collected before neoadjuvant chemotherapy. Pathologic complete response (pCR) was defined as the absence of invasive carcinoma in the breast and axillary lymph nodes. Residual cancer burden (RCB) was also calculated in 79 cases. @*Results@#Twenty-two patients achieved pCR (23.2%). The rates of estrogen receptor (ER) negativity (p=0.04), progesterone receptor (PR) negativity (p=0.03), and nuclear grade 3 (p=0.03) were higher in patients with pCR than those in patients without pCR. The rates of PR negativity (p=0.03), nuclear grade 3 (p=0.01), and high tumor-infiltrating lymphocyte (TIL) levels (p=0.04) were significantly higher in the favorable RCB group (RCB-0 and I) than those in the unfavorable RCB group (RCB-II and III). No significant difference in tumor elasticity was observed between the groups (p=0.30). Hormone receptor (HR) negativity was an independent predictor of favorable RCB in the multivariate analysis (p=0.04). @*Conclusion@#Tumor elasticity was not associated with pCR or RCB. HR negativity was an independent predictor of favorable RCB.