A case and review of bowel perforation secondary to metastatic lung cancer.

Gastrointestinal tract perforation (GITP) secondary to metastatic lung cancer is extremely rare. We present a case of small bowel perforation secondary to metastatic lung cancer. The objective of this study was to review the current literature and further characterize the incidence, histology, and risk of GITP secondary to lung cancer metastasis. A Medline search was done to identify all the cases of GITP attributed to metastatic lung cancer reported in the literature. Data was collected and analyzed from a collection of cases in the medical literature since 1960. We identified 98 cases of perforated lung cancer metastasis to the small intestine. Four gastric perforations, three colonic perforations, and one appendiceal perforation were also identified but not analyzed. The mean age was 64.5 years. There was a male predominance of 89 per cent versus 11 per cent female. Perforations occurred most often in the jejunum (53%) followed by ileum (28%). Combined jejunum-ileum lesions accounted for 4 per cent of perforations. No duodenal perforations were reported, though a specific site was not determined in 13 per cent of cases. Small bowel perforations were most often caused by adenocarcinoma (23.7%), squamous cell carcinoma (22.7%), large cell carcinoma (20.6%), and small cell carcinoma (19.6%). The prevalence of small bowel perforation secondary to a given primary lung cancer histology varied by region. The mean survival was 66 days with 50 per cent of patients not surviving past 30 days. Despite a high incidence of lung cancer, small bowel perforation secondary to lung cancer metastasis remains relatively rare. Perforated metastases occur more often in men and are found more commonly in the jejunum. Small bowel perforations are caused most often by adenocarcinoma; however, squamous cell and large cell carcinoma metastases are more likely to result in perforation. Small bowel perforation in this setting has a significant impact on mortality, decreasing 1-year survival to less than 3 per cent.