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

Abstract

BackgroundIn 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).MethodsData 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 = 3/1/7/8). 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 45–60 Gy. A total of 16 of the 19 patients received chemotherapy.ResultsPatients were divided into two groups, one with a Ki-67 proliferation index ≥79.77% (group 1, 8 cases) and the other with a Ki-67 proliferation index <79.77% (group 2, 11 cases). Following radiation therapy, a complete response (CR) was observed in six cases from group 1 (75.0%) and three cases from group 2 (27.3%). The Ki-67 proliferation index was significantly correlated with the CR rate (P = 0.05), which was significantly higher in group 1 than in group 2 (P = 0.04). The median survival time was 516 days for all patients, and the survival rates did not differ significantly between groups 1 and 2.ConclusionsOur study is the first to evaluate the correlation between the Ki-67 proliferation index and SCLC tumour response to radiation therapy. Our findings suggest that a high Ki-67 proliferation index might represent a predictive factor for increased tumour radiosensitivity.

Cut‐point for Ki‐67 proliferation index as a prognostic marker for glioblastoma

“…To explain these findings, it was proposed that tumors with increased proliferation may be more prone to the cytotoxic effects of chemoradiotherapy, reminiscent of other highly proliferative tumor types such as lymphoma . Other studies have found a similar association with small cell lung cancer and breast cancer . The findings in this study certainly appear to support this hypothesis.…”

Long non‑coding RNA transcribed from pseudogene PPIAP43 is associated with radiation sensitivity of small cell lung cancer cells

“…A previous study demonstrated that an increased Ki-67 proliferation index may represent a predictive factor for increased tumor radio-sensitivity (36). The present study identified a potential radio-sensitivity indicator for SCLC cell lines following early radiation in vitro.…”

Correlation between radiomic features based on contrast‐enhanced computed tomography images and Ki‐67 proliferation index in lung cancer: A preliminary study

“…Previous studies have shown that a high Ki‐67 PI has a negative impact on disease‐free survival, relapse‐free survival, and overall survival in non‐small cell lung cancer . Moreover, the most recent World Health Organization (WHO) classification has adopted the Ki‐67 PI for the diagnosis of small cell lung cancer (SCLC) and a higher Ki‐67 PI may represent a predictive factor for increased tumor radiosensitivity in SCLC . Hence, Ki‐67 may be a valuable biomarker for predicting the prognosis of lung cancer patients.…”

“…3,4 Moreover, the most recent World Health Organization (WHO) classification has adopted the Ki-67 PI for the diagnosis of small cell lung cancer (SCLC) and a higher Ki-67 PI may represent a predictive factor for increased tumor radiosensitivity in SCLC. 5 Hence, Ki-67 may be a valuable biomarker for predicting the prognosis of lung cancer patients. The conventional method for detecting Ki-67 expression is immunohistochemistry, which is a test involving invasive biopsy or surgical samples.…”