Head or Neck Most Commonly Affected Region by Keratinocyte Carcinomas in US Medicare Population

Navsaria LJ, Li Y, Tripathy S, Cox ML, Hinkston CL, Margolis DJ, Wehner MR. Anatomic Locations of Procedurally Treated Keratinocyte Carcinomas in the US Medicare Population. JAMA Dermatol. 2023 Jun 1;159(6):643-647. doi: 10.1001/jamadermatol.2023.0611. PMID: 37074701; PMCID: PMC10116380.

The head and/or neck was the most common anatomic location for keratinocyte carcinoma to occur (53.8%), followed by the upper limb (17.8%)

Clinical Pearls

• Using Medicare claims data, the authors investigated the relationship between keratinocyte carcinomas and anatomic location

• The head and/or neck was the most common anatomic location for keratinocyte carcinoma to occur (53.8%), followed by the upper limb (17.8%)

• A statistically significant increased odds of developing squamous cell carcinoma rather than basal cell carcinoma was found with increasing age and male sex

Discussion:

In this study, Navsaria et al sought to better understand the relationship between keratinocyte carcinoma location and patient demographics in the United States. Of note, the authors mentioned a scarcity of data in this area within the literature.

This cohort study used a deidentified, random sample of 100% Medicare claims data from the years of 2009-2018. It included 4,999,999 Medicare beneficiaries 65 years or older with at least one procedurally treated keratinocyte carcinoma. Logistic regression was used to determine the relationship between keratinocyte carcinoma subtype and anatomic location while adjusting for demographic variables.

Around 2.4 million procedurally treated keratinocyte carcinomas were included in this study with basal cell carcinoma, squamous cell carcinoma, and carcinomas not able to be subtypes composing 33%, 38.4%, and 28.6% of the sample respectively. The authors found that the head and/or neck was the most common anatomic location for keratinocyte carcinomas to occur (53.8%), followed by the upper limb (17.8%). The majority of basal cell carcinomas were found on the head and neck (63.8%) while a slightly less than half of squamous cell carcinomas were as well (44.3%). Keratinocyte carcinomas were found to occur more often in men than women (57% vs 43 %, p < 0.001). Following multivariate logistic regression, the authors found a statistically significant increased odds of a keratinocyte carcinoma being squamous cell carcinoma rather than basal cell carcinoma with increasing age (OR, 1.03 per 10-year increase, 95% CI, 1.03-1.03) and male sex (OR, 1.06; 95% CI, 1.05-1.06).

Overall, this study provides valuable insight into the anatomic location of keratinocyte carcinomas in the United States, however, is limited by its use of only procedurally treated cancers (possibly creating bias towards head and neck carcinomas).