Correlation between the Ki-67 proliferation index and response to radiation therapy in small cell lung cancer

Abstract Background In the breast cancer, the decision whether to administer adjuvant therapy is increasingly influenced by the Ki-67 proliferation index. In the present retrospective study, we investigated if this index could predict the therapeutic response to radiation therapy in small cell lung cancer (SCLC). Methods Data from 19 SCLC patients who received thoracic radiation therapy were included. Clinical staging was assessed using the TNM classification system (UICC, 2009; cstage IIA/IIB/IIIA/IIIB\u2009=\u20093/1/7/8). Ki-67 was detected using immunostained tumour sections and the Ki-67 proliferation index was determined using e-Count software. Radiation therapy was administered at total doses of 45\u201360\ua0Gy. A total of 16 of the 19 patients received chemotherapy. Results Patients were divided into two groups, one with a Ki-67 proliferation index \u226579.77% (group 1, 8 cases) and the other with a Ki-67 proliferation index