Comorbidity in elderly NSCLC patients.

We read with interest the report by JanssenHeijnen and associates on the effect of comorbidity on the treatment and prognosis of elderly patients with non-small cell lung cancer (NSCLC). The authors concluded that the number of comorbid conditions had no significant influence on the treatment chosen for patients with non-localised disease. We share the authors’ opinion that ‘‘comorbidity had no independent prognostic effect’’. In their report, the authors used the Charlson comorbidity index and analysed the number of comorbid conditions. However, they did not examine the scoring system of the index. We would like to know why the authors did not use the scoring of the index, and whether the conclusion would be changed if the scoring system was used. In the original article by Charlson et al and other related studies, ‘‘angina pectoris’’ was not evaluated as one of the cardiovascular comorbid diseases. However, JanssenHeijnen et al included ‘‘angina pectoris’’ as a comorbid disease although they did not describe it precisely. We consider this inclusion is reasonable, and we would appreciate hearing from the authors whether ‘‘angina pectoris’’ would be evaluated as one of the cardiovascular comorbid diseases in future studies to evaluate the effect on mortality, and what score it should be assigned.