Background: Plain chest film is the most convenient and common tool used to evaluate the response of lung cancer to chemotherapy. Many authors tried to evaluate the use of plain chest films to predict chemotherapy response. This study investigated a new factor which could be used to predict the chemotherapy response of small cell lung cancer (SCLC).
Methods: Sixty-two patients with cytopathologically proven small cell lung cancer receiving at least two courses of chemotherapy were included in this study. Among these patients, thirty-nine patients received six courses of chemotherapy. The regimens of chemotherapy are Etoposide (100 mg/m2) and Cisplatin (25 mg/m2). We divided these patients into two groups according to whether a well-defined pulmonary lesion excluding hilar and mediastinal lymphoadenopathy, could be identified on plain chest X-ray (CXR). Group I consisted of 31 patients with identified lesions on the CXR; group II consisted of 31 patients with unidentifiable lung lesions. CXRs were taken each time before chemotherapy and were collected and compared to evaluate the chemotherapy response. The 39 patients receiving six course of chemotherapy, were further divided into group I (n = 19) and group II (n = 20) to evaluate the chemotherapy response.
Results: After two courses of chemotherapy, we found 23 patients [74.2% (23/31)] in group I had partial response(PR) as compared to 12 patients [38.7% (12/31)] in group II (P < 0.05). For the 39 patients receiving six courses of chemotherapy, we could find only five patients [16.1% (5/19)] in group I who had a complete response (CR) as compared to 17 patients [85% (17/20)] in group II (P < 0.001).
Conclusion: For patients with SCLC, a well-defined lung lesion on a CXR could be an important new factor to predict the chemotherapy response. It could predict less responsiveness to chemotherapy.