The incidence of keratinocyte carcinoma decreased from 1998 to 2003, then increased through 2017, according to a study published online Oct. 4 in CMAJ, the journal of the Canadian Medical Association.

Evan Tang, from the University of Toronto, and colleagues examined the difference by sex in incidence and mortality rates of keratinocyte carcinoma among adults in Ontario between Jan. 1, 1998, and Dec. 31, 2017. Trends were examined using the average annual percentage change (AAPC).

The researchers found that from 1998 to 2003, there was a decrease in the incidence rate of keratinocyte carcinoma, followed by a 30 percent increase to 369 and 345 per 100,000 for men and women, respectively, in 2017 (AAPC, 1.9 percent from 2003 to 2017). The incidence rate was higher in women younger than 55 years and in men aged 55 years and older. Between 2008 and 2017, the incidence rate increased faster in women aged 45 to 54 years and aged 55 to 64 years (AAPCs, 1.2 versus 0.5 percent and 1.2 versus 0.1 percent, respectively). In the higher income quintiles, incidence was higher in men than women. The mortality rate of keratinocyte carcinoma was 1.8 times higher in men than women between 1998 and 2017 and increased 4.8-fold overall (AAPCs, 8.9 and 8.0 percent in men and women, respectively).

"The increasing incidence rates (particularly in younger females) and disproportionately rising mortality rates of keratinocyte carcinoma are concerning," the authors write. "Renewed public health efforts are warranted to promote preventive measures, patient education, and early diagnosis."

Abstract/Full Text