Aims: The aim of this study is to investigate patients with unresectable Stage III non-small-cell lung cancer (NSCLC) receiving radiotherapy with induction and concurrent pemetrexed or docetaxel plus cisplatin (PP/DP) chemotherapy and to identify the subgroup most likely to benefit from induction chemotherapy (IC).
Subjects and methods: Patients with unresectable measurable Stage III NSCLC received two cycles of PP/DP IC followed by concurrent chemoradiotherapy at a dose of 60-66 Gy.
Statistical analysis used: Cox regression analysis was performed to evaluate the prognostic factors for survival; logistic regression analysis was used to evaluate the predictors for response to IC, and the receiver operating characteristic curves were used to evaluate the independent factors predicting response.
Results: Eighty patients were included; the median survival time (MST) was 22.1 months. Partial response (PR) to IC was an independent prognostic factor for overall survival. For patients in the PR and stable disease groups, the MST was 36.7 and 19.5 months, respectively. The independent predictors of PR to IC included classification as stage N3 cancer, baseline carcinoembryonic antigen (CEA) levels >10 ng/ml, and cytokeratin fragment 19 (CYFRA21-1) levels >6 ng/ml. With each additional independent predictor, the likelihood of having have PR to IC increased.
Conclusions: Radiotherapy with induction and concurrent PP/DP chemotherapy is feasible for patients with unresectable Stage III NSCLC. IC may improve the survival of IC responders, as predicted by elevated CEA and CYFRA21-1 levels and classification as stage N3 cancer. Additional randomized trials on IC may consider these predictors to tailor individualized treatments.
Keywords: Carcinoembryonic antigen; Stage III non-small-cell lung cancer; cytokeratin fragment 19; induction chemotherapy; partial response.