Study Assesses Childhood Cancer Survivors’ Risk for KCs

TOPLINE:

The cumulative incidence of keratinocyte carcinomas (KCs) among childhood cancer survivors (CCS) over 20 years after diagnosis was 1.5% overall and among those exposed to radiation therapy was 2.6%.

METHODOLOGY:

• Researchers evaluated the incidence of KCs over 20 years in 25,658 participants (80.5% White) in the CCSS cohort who were diagnosed with cancer before the age of 21 years between 1970 and 1999 in North America and survived at least 5 years.
• Information on patient demographics, treatment exposure, and the occurrence of KCs was collected through self-reported questionnaires and verified using medical records and pathology reports.
• Radiation therapy exposure and cumulative chemotherapy doses were also calculated.

TAKEAWAY:

• A total of 1446 individuals (52.9% women and 95.3% White) developed 5363 KCs (93.5% were basal cell carcinomas, and 6.7% were squamous cell carcinomas) at a mean age of 37 years (range, 7.3-67.4 years). The mean latency from the primary cancer diagnosis was 25.7 years (range, 5.2-46.6 years).
• The 20-year cumulative incidence of KCs was 1.5% for all survivors and 2.6% for those exposed to radiation therapy. The incidence decreased from 2% among those diagnosed in the 1970s to 1% among those diagnosed in the 1990s (P < .001) but did not plateau in any of the decades.
• The predominant risk for KC was radiation therapy (relative risk [RR], 4.54; P < .001), which was associated with a higher incidence of KCs. (88.4% of survivors with KCs had received radiotherapy.)
• Both allogeneic (RR, 3.4; P < .001) and autologous (RR, 2.3; P = .009) hematopoietic cell transplants were associated with increased KC rates.

IN PRACTICE:

“While the burden of KC in survivors remains much higher than in the general population, it is encouraging that the cumulative incidence has decreased in more recent treatment eras,” the authors wrote. The study, which, they added, “provides the largest longitudinal profile of KC in CCS to date and highlights the need for healthcare provider awareness of skin cancer risk in survivors and ongoing screening vigilance.”

SOURCE:

The study was led by Christina Boull, MD, University of Minnesota, Minneapolis, and was published online on August 23, 2024, in the Journal of the American Academy of Dermatology.

LIMITATIONS: 

Participants did not report their skin phototype, a more specific marker of susceptibility to ultraviolet injury. Complete genetic information was not available, which limited the assessment of syndromes like basal cell nevus syndrome and xeroderma pigmentosum. Analysis of radiation therapy exposure included maximal radiation exposure but did not account for the volume or surface area of irradiated tissue.

DISCLOSURES:

The study was supported by the National Cancer Institute and the American Lebanese Syrian Associated Charities. Boull disclosed consulting for SpringWorks Therapeutics. Two other authors reported receiving royalties, grants, and advisory fees outside this work.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.