Diagnosis of multiple primary lung cancer: a systematic review.

A substantial percentage (8%) of all newly diagnosed cancer cases are in patients with previous tumours, with a similar trend in lung cancer. Cases of multiple primary lung cancer (MPLC) are increasing worldwide, due to improved diagnostic and surveillance mechanisms and the ageing population. Diagnosis of MPLC is complicated by difficulties in distinguishing it from lung cancer metastasis. Clinicopathological assessment, diagnosis and management have evolved, but remain severely limited by the lack of robust and dependable molecular markers for the differential diagnosis of metastasis and MPLC. This systematic review evaluates diagnostic criteria for MPLC, and the subsequent management and success rates. The incorporation of molecular biology techniques into the diagnostic process for MPLC is also discussed.