An overview of prognostic factors in small cell lung cancer

Abstract

Several studies of small cell lung cancer (SCLC) treatments have been performed in the United Kingdom. In some, prognostic factor analyses were carried out but the results were not entirely consistent. The Lung Cancer Subcommittee of the United Kingdom Coordinating Committee on Cancer Research (UKCCCR) consequently initiated an overview of these studies with the aim of identifying the important prognostic factors using a large number of patients. Information on almost 4,000 patients was available, but it was necessary to perform analyses on smaller subsets because the variables recorded in individual studies were inconsistent. A number of variables contributed significantly to the prediction of likely survival over the 6 months after starting treatment, but performance status (PS), alkaline phosphatase (AlkP) and disease stage were shown to be the most important; aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) may also be useful. A prognostic index was devised for this initial period and validated using independent data. For patients who survived the first 6 months, the pre-treatment variables important for prognosis in the 6-24 month period were stage, PS and plasma sodium (Na). The Subcommittee recommends that performance status, disease stage, AlkP, Na, AST and LDH should be measured in all future SCLC studies to assist comparisons between studies and possibly the selection of patients for different treatment strategies. The additional recording of five other variables would allow a more definitive overview to be performed at some future date.