Identifying and screening patients at risk of second cancers

The average age of the U.S. population is increasing, and cancer incidence increases with age. Both improved early detection of first malignancies and effective primary oncologic therapy have led to prolonged survival, and the risk of secondary malignancies has consequently increased. A few anatomic sites are at increased risk for second malignancies within the same organ: breast, colon and rectum, lung, head and neck (or upper aerodigestive malignancies), prostate, and the uterine cervix. Some of the cancers also incur a risk for a second malignancy at another anatomic site. In addition, there are well-described clinical genetic syndromes that, as unique clinical entities, predispose to second malignant tumors.

In this review, we focus on issues related to the risk of second malignancies among patients with primary breast, colon, lung and head and neck, prostate, and cervical cancers that comprise the most common sites of primary malignancy among patients in the United States. We review recent data related to both established and new screening strategies at these sites.

There is some evidence that screening will improve outcomes among patients who may develop second malignancies, although the data are limited. The optimal screening modalities and strategies to reduce mortality from second malignancies remain to be defined for most tumor sites.