The population of cancer survivors in the United States is growing, and some of these survivors will develop a second cancer. To determine the prevalence of a prior cancer among people newly diagnosed with cancer, researchers in Dallas, Texas analyzed Surveillance, Epidemiology, and End Results (SEER) data. Cancers were categorized as first or only primary, second order or higher primary in the same cancer site, and second order or higher primary in a different cancer site.
Of 765,843 cancers diagnosed between 2009 and 2013, 141,021 (18.4%) represented a second order or higher primary cancer. The researchers found that 25.2% of people 65 years or older and 11% of younger adults newly diagnosed with cancer had a history of prior cancer. Prevalence of a prior cancer ranged from 3.5% to 36.9% according to incident cancer type and age, with most prior cancers diagnosed in a different cancer site.
The researchers concluded that there is a growing subgroup of people with cancer who have survived a prior cancer. Often, these patients are excluded from clinical trials and underrepresented in research, noted the researchers.
“Understanding the nature and impact of prior cancer is critical to improving clinical trial accrual and generalizability, disease outcomes, and patient experience,” wrote the authors.
Additional research must be done to identify treatment and survivorship needs.