From the Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland
Author's disclosure of potential conflicts of interest is found at the end of this article.
Address reprint requests to Lois B. Travis, MD, ScD, 1275 E. First Avenue, #159, New York, NY 10065; e-mail: travis1122{at}optonline.net
Overview: Significant improvements in cancer detection, supportive care, and therapeutic advances in the past few decades have resulted in increasing numbers of cancer survivors. In 2004, in the United States alone, there were an estimated 10.7 million cancer survivors, with an overall 5-year relative survival rate of almost 66%. Given the major strides in survival rates for increasing numbers of patients, identification and characterization of the late sequelae of cancer and its treatment have become critical. The diagnosis of a new cancer represents one of the most serious events experienced by cancer survivors. The number of patients who develop second or higher-order cancers is increasing, with these diagnoses comprising approximately 16% (or 1 in 6) of incident cancers reported to the National Cancer Institute's Surveillance, Epidemiology, and End Results program in 2004. Solid tumors are an important cause of mortality among a number of groups of long-term survivors, in particular, patients with Hodgkin's lymphoma. However, multiple primary cancers may reflect not only the late effects of therapy but also the influence of additional factors, including nutrition and hormones, infections and immunosuppression, genetic predisposition, other host factors, environmental determinants, and the operation of joint effects, including gene–environment and gene–gene interactions. In this article, we highlight selected results from a systematic review of second primary cancers (among more than 2 million cancer survivors) reported from population-based cancer registries to the National Cancer Institute's Surveillance, Epidemiology, and End Results program between 1973 and 2000.
