[Clinical characteristics and prognosis of different subtypes of breast cancer]

To investigate the clinical characteristics and prognosis of patients with different subtypes of breast cancer: basaloid, HER-2 and luminal types, and try to find the evidence of individualized treatment for the patients.

1280 histologically and immunohistochemically proven patients with resectable breast cancer were treated, and the clinical data including characteristics, relapse and survival of the patients with different subtypes of breast cancer were analyzed retrospectively.

Of the 1280 breast cancer patients, basaloid, HER-2 and luminal types accounted for 20.9%, 23.2% and 55.9%, respectively. Basaloid type was more likely to be found in younger patients frequently with a family history of breast cancer. HER-2 type usually had a tumor of larger size with more advanced stage disease and more metastatic lymph nodes. Luminal type was likely to occur in aged patients with an earlier stage disease. The recurrence rates in basaloid, HER-2 and luminal types were 25.0%, 27.9% and 11.7%, respectively. Patients with basaloid or HER-2 type were found to have a significantly higher recurrence rate than the patients with luminal type breast cancer (P < 0.001), but no significant difference was observed between the basaloid and HER-2 types. However, patients with basaloid type breast cancer were more likely to develop lung metastasis than HER-2 type (13.4% vs. 7.1%, P = 0.017). Up to December 2006, the 5-year disease-free survival (DFS) rates for patients with basaloid, HER-2 and luminal types were 72.2%, 68.2% and 86.2% (P < 0.001), respectively. The overall 5-yr survival (OS) rates of the three groups were 88.6%, 83.8% and 95.8% (P < 0.001) , respectively. Of the patients with luminal type breast cancer, HER2-negative patients had a higher DFS (86.2% vs 57.0%, P < 0.001) and OS (95.8% vs 87.7%, P = 0.0001) compared with those with HER2-positive. The results of Multivariate Cox Regression showed that tumor size and lymph node state were the most important factors influencing the prognosis.

Each subtype of breast cancer has somewhat its own specific clinical features in terms of recurrence pattern and prognosis, therefore, individualized treatment regimen may be required.