Metachronous cancer.

Metachronous cancer (multiple primary tumors developing at intervals) will appear more commonly as cancer patients live longer lives. In this report, we use data from the Rhode Island Cancer Registry to look at commonly occurring metachronous cancers, their frequency over time, and the implications for cancer survivorship. Sequence two (refers to the chronologically second primary tumor diagnosed for a given patient) and higher primary malignant neoplasms were identified in cancer case reports made to the Rhode Island Cancer Registry, 1987-2009, and used to construct annual, age-adjusted, sequence-specific incidence rates for all cancers combined, and age-adjusted, site-specific incidence rates for common second and higher-order primary malignant neoplasms over the entire observational period. During the period of observation, the proportion of all cancers diagnosed as sequence two and higher primary tumors among males increased steadily from 11.5 to 20.3 percent, while the proportion of all cancers diagnosed as sequence two and higher primary tumors among females increased from 12.8 to 20.7 percent. A mere four cancer types--lung (and bronchus), colon (and rectum), breast, and prostate--account for over half of all sequence two and higher cancer diagnoses (54.3 percent). The average interval between first cancers and second cancers is 6.5 years for men and 4.8 years for women. Such is the "career" of a cancer survivor today that he or she has about a one in four chance of developing a second cancer. This statistic suggests the need for strong and lasting social support networks. Furthermore, the average interval between first and second cancers is substantial, and suggests opportunities for interventions (prevention and screening) that might reduce the burden of sequence two and higher cancers.