How common are new cancers in cancer survivors?

The number of cancer survivors in the United States is growing and is estimated to reach 26 million by 2040. Understanding how common a subsequent cancer is among patients with a history of cancer is important for understanding ongoing or new cancer risk in survivors.

For this study, 740,990 people diagnosed with new cancer from 2009 through 2013 participated. The study specifically measured prior cancer among people diagnosed with a new cancer. This was an observational study. Because researchers are not intervening for purposes of the study. they cannot control natural differences that could explain study findings.

Results shows that the frequency of prior cancer among patients diagnosed with new cancer ranged from 3.5 percent to 36.9 percent and most prior cancers were diagnosed in a different cancer site. The order of multiple cancers diagnosed in the same year could not be determined.

In conclusion, patients diagnosed with new cancer who have a history of cancer may be excluded from clinical trials and underrepresented in research. Understanding the impact of prior cancer is important to improve research, disease outcomes and patient experience.