[Double cancer in small cell lung cancer patients treated with intensive chemotherapy with or without radiation...

Development of double cancer was evaluated in 311 small cell lung cancer patients who had received intensive chemotherapy with or without radiotherapy. Of those, 10 patients (3.2%) developed a second malignancy:stomach cancer in four, non-small cell lung cancer in three, acute myelogenous leukemia in two, and liver cancer in one. The cumulative risk for the development of double cancer was 1.0% at 1-year, 17.0% at 3-years, and 100% at 8.1 years. The relative risk for the development of double cancer calculated by person-year method utilizing age and sex adjusted cancer incidence in Japan was 2.96-fold (p less than 0.01). The risk of non-small cell lung cancer (6.65-fold) and acute myelogenous leukemia (54.9-fold) was particularly high. Of 21 patients who survived disease-free for more than 2 years, 8 patients died; four patients (50%) died of second malignancy, two died of infectious disease, and only two patients died from recurrent small cell lung cancer. These results indicate that a cautious follow-up program for the detection of double cancer is indicated in patients surviving small cell lung cancer.