[The influence of molecular classification of breast cancer on the safety of breast-conserving surgery].

Objective: To analyze the relationship between the breast cancer molecular classification and the prognosis of patients underwent breast-conserving therapy and to discuss the safety of the breast conserving surgery from the choice of operation in terms of breast cancer molecular classification. Methods: Clinical data of 618 patients with breast-conserving therapy in Tianjin Medical University Cancer Institute and Hospital from August 2005 to August 2010 were analyzed retrospectively. According to the molecular classification when breast cancer was diagnosed, patients were subdivided into five groups, including Luminal A, Luminal B1, Luminal B2, HER-2-positive and Triple-negative. Clinicopathological characteristics and prognosis were compared among five groups and the influencing factors of local recurrence, distant metastasis and overall survival were analyzed. Results: Among 618 patients, there were 148 cases Luminal A, 231 cases Luminal B1, 63 cases Luminal B2, 40 cases HER-2-positive and 136 cases Triple-negative. The age, family history, TNM stage, calcification, histological grade, pathological type and response to endocrine therapy of these 5 molecular types of breast cancer patients were significantly different (all P <0.05). The 5-year local regional recurrence-free survival rates of Luminal A, Luminal B1, Luminal B2, HER-2-positive and Triple-negative were 99.3%, 98.7%, 98.4%, 94.9% and 95.9%, respectively, without significant differences ( P =0.104). The 5-year distant metastasis-free survival rates of these 5 types were 97.3%, 95.7%, 93.7%, 87.5% and 91.4%, respectively, with significant differences ( P =0.013). Moreover, the 5-year overall survival rates of these 5 types were 98.6%, 97.8%, 98.4%, 92.5% and 95.6%, respectively, without significant differences ( P =0.153). Multifactor analysis showed that radiotherapy ( HR =0.036, P =0.049) and the number of lymph node metastases ( HR =10.72, P =0.004) were independent factors of local recurrence of breast cancer patients underwent breast-conserving therapy. The age ( HR =0.369, P =0.046), status of surgical margin ( HR =5.486, P =0.007), number of lymph node metastases ( HR =2.882, P =0.023) and molecular typing ( HR =5.191, P =0.008) were independent factors of distant metastasis of above breast cancer patients. None of the factors were found to be independent factors of the overall survival of these breast cancer patients. Conclusions: Breast conserving therapy does not increase the risks of local recurrence and death of HER-2-positive and Triple-negative breast cancer patients. Therefore, breast conserving therapy can be accepted by patients with HER-2-positive and Triple-negative breast cancer.