Lung cancer patients with synchronous colon cancer.

Lung and colon cancers are two of the most common malignancies, which, in some cases, may develop synchronously. In the present study, the treatment and outcome of patients with synchronous lung and colon cancers were reviewed. During a 76-month study period, from April 2009 up to July 2016, 17 (0.54%) of 3,102 patients with lung cancer were diagnosed with colon cancer within 1 month. Heavy smoking and obesity were not specific factors in these patients. A total of 9 patients succumbed to lung cancer during the study period. Survival in asymptomatic patients was longer compared with that in symptomatic patients (median survival, 80 vs. 23.2 months, respectively; P=0.007). Although the incidence of synchronous occurrence of these two cancers may be low, particularly in patients diagnosed incidentally, such patients should be treated accordingly. Future genetic and epidemiological studies are required to elucidate the potential connection between lung and colon cancer.