Clinical Features And Prognosis Of Molecular Subtypes Of Breast Cancer

Objective：To analyze the clinical features and prognosis of molecularsubtypes of breast cancer，and try to find the evidence of individualizedtreatment for the patients.Methods: A total of356cases of breast cancer were analyzedretrospectively.The classification of breast cancer was according to theimmunohistochemical results of estrogen receptor(ER)，progesteronereceptor(PR) and human epidermal growth factor receptor-2(HER-2)status.Molecular classification definitions included luminal A subtype，luminal B subtype，HER-2over-expression subtype and triple negativebreast cancer.The clinicopathological features and recurrence，metastasis as well as survival of these four subtypes were analyzed.Results： Among the356cases，luminal A subtype accounted for56.5％(201/356)，luminal B subtype14.6％(52/356)，HER-2over-expressionsubtype11.0％(39/356)，and triple negative subtype17.9％(64/356).Thetumor size of triple negative subtype was significantly bigger thanluminal A subtype（P=0.005）.52.1％of triple negative breast carcinomaswere histologically grade3，higher than luminal A subtype（P=0.001）.Themedian follow-up time was23.5months，and local recurrence，distantmetastasis and fatality rate were4.7%，18.6%，7.5%，respectively.Therewas no significant difference in local recurrence between differentgroups（P>0.05）.The rate of distant metastasis in triple negative subtypewas significantly higher than that in luminal A subtype(32.0％vs16.5％,P＝0.009）.The occurrence rates of lung metastasis were significantlyhigher in triple negative subtype than in luminal A subtype and HER-2subtype（P<0.01）.The3-year overall survival rates (OS) for patients withluminal A，luminal B,HER-2and triple negative breast cancer were96.5%，90.0%，84.0%and86.0%，respectively.The5-year overall survival rates (OS) of the four subtypes were95.0%，81.0%，84.0%and64.0%，respectively.No significant difference was observed between differentgroups（P>0.05）. The3-year disease-free survival (DFS) rates forpatients with luminal A，luminal B，HER-2and triple negative breast cancerwere96.5%，94.0%，88.0%and87.0%，respectively.The5-year disease-freesurvival (DFS) rates of the four subtypes were91.0%，71.0%，81.0%and51.0%， respectively.The DFS time in triple negative subtype was shorterthan that in luminal A subtype（P=0.023）.Conclusions：Each subtype of breast cancer had somewhat its own specificclinical features，relapse and survival were also different respectively.Triple negative breast cancer usually had a tumor of larger size andhistologically grade3.Patients with triple negative subtype breastcancer were more likely to develop distant metastasis,and had high ratesof lung metastasis. Triple negative subtype had a poor prognosis.Whileluminal A was the most common subtype in Chinese breast cancerpatients,and had a good outcome. Molecular subtype of breast cancercould help realize features of molecular biology，guide clinical treatmentand predict prognosis.