Comparative study of breast cancer shrinkage modes after neoadjuvant chemotherapy and corresponding morphological and molecular biological characteristics

Objective: To evaluate the breast cancer shrinkage modes after neoadjuvant chemotherapy and corresponding morphological and molecular biological characteristics. Methods: There were 22 patients with histologically confirmed breast cancer from January 2011 to December 2014 were collected. All patients were examined with dynamic enhancement magnetic resonance imaging before neoadjuvant chemotherapy and after four cycles neoadjuvant chemotherapy, underwent radical mastectomy within two weeks after neoadjuvant chemotherapy. The correlation breast cancer shrinkage mode with lesion subtypes and chemotherapy reaction classification and molecular biological characteristics were analyzed with independent sample t test and the Fisher's exact test, respectively. Results: Of 22 invasive ductal carcinoma, after neoadjuvant chemotherapy, 14 patients presented concentric shrinkage, 8 patients presented multi-concentric shrinkage. The cancer shrinkage proportion of the concentric group and multi-concentric group were 71.8%± 28.3% and 38.7% ± 24.8%, respectively. There was significant difference in shrinkage volume between concentric group and multi-concentric group (t = 2.757, P = 0.012). The tumors with concentric shrinkage on MRI showed more mass lesions (11/14, 78.6%) and the tumors with multi-concentric shrinkage showed more non-mass lesions (6/8, 75%) after neoadjuvant chemotherapy, which was significant between the 2 groups (P = 0.026). There were no significant differences in chemotherapy reaction classification, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor-2 (HER2), p53, Ki-67, and molecular types between breast cancer shrinkage modes (P > 0.05). Conclusions: The breast cancer shrinkage modes after neoadjuvant chemotherapy correlate with morphology characteristics of breast cancers before neoadjuvant chemotherapy. The tumors with concentric shrinkage on MRI present more mass lesions and the tumors with multi-concentric shrinkage present more non-mass lesions. (authors)