Clinical Corner - October 2023

The number of cancer survivors in the United States is expected to exceed 22 million by 2030, according to the American Cancer Society. A prior study showed 18.4% of adults diagnosed with an incident cancer between 2009 and 2013 had survived a prior malignancy.

Registry information is critical in highlighting the importance of this trend of second or third malignancies in cancer survivors. Subsequent malignancies in cancer survivors can be assessed by differences in age, sex, race and ethnicity using registry data.

A recent study determined that 1.73 million people in the United States had been diagnosed with a new cancer in 2019 with 19.4% of them surviving a prior cancer. These included 1.9% who survived a prior cancer of the same type, 8.6% who had survived a different form of cancer, and 8.9% who had survived an unknown type of prior cancer.

A diagnosis of a new incident cancer different from the prior malignancy appeared more common among older adults (14.1% for those aged 65 years or older vs. 1.6% for those aged 18 to 49 years). This also appeared more common among men than women (10.3% vs. 8.9%), and among non-Hispanic white individuals than non-Hispanic Black individuals (11% vs. 5.7%). 

Researchers also reported differences in prevalence by cancer type. Unfortunately, these individuals may have been excluded from clinical trials due to their prior cancer. Approximately two-thirds of NCI-supported trials from 2018 to 2020 excluded patients with prior or concurrent cancers.

As you review data for patient abstracts and determine the “sequence code” indicating a subsequent malignancy, consider the importance of this information in constructing trials for future cancer survivors.