The incidence of pancreatic cancer—which historically has been higher in men than in women—has increased among both men and women during the past decade, with a significantly greater relative increase observed in women younger than age 55 years, and especially among those aged 15 to 34 years. These findings were reported as a research letter by Gaddam et al in JAMA.
The researchers obtained data from the Surveillance Epidemiology and End Results (SEER) database from 2000 to 2018. The investigators employed sex- and age-specific “time-trend” analysis.
Based on earlier, noncomparative SEER-based research, scientists already knew that the incidence of pancreatic cancer in White, older women and men and White non-Hispanic young women was increasing. However, limited data existed that showed recent trends in pancreatic cancer incidence.
Changes in Pancreatic Cancer Cases
The researchers discovered that, overall, the average annual percentage change of total pancreatic cancer cases increased by 0.78% in women and 0.90% in men, reflecting no statistically significant difference between the two groups. But, broken down by sex—half of the study patients were women—the average annual percentage change in women younger than age 55 was 1.93%, compared with 0.77% in men, representing a “significant difference,” said lead study author Srinivas Gaddam, MD, Assistant Professor of Medicine at Cedars-Sinai Medical Center.
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Additionally, the average annual percentage change among women aged 35 to 54 years increased by 1.56%, compared with 0.65% among men in the same age group. The rate of change in women aged 15 to 34 years was 7.68%, compared with 4.20% in men.
“These findings are important because this is the first time, using the most current data, that we are reporting that pancreatic cancer rates are increasing dramatically in women who are younger than 55,” Dr. Gaddam explained. “The findings are most dramatic in women [younger] than 35 years old.”
While significant, Dr. Gaddam emphasized that this study is only the first of potentially several future investigations. His team is interested, for example, in the possible causes for the increase in pancreatic cancer rates among younger women,which may include chemical contaminants women are exposed to, birth rates, and birth control hormones, among others.
Meanwhile, “Women with abdominal pain should not run to their primary care physicians and ask for a… scan,” Dr. Gaddam said. “The incidence of this cancer is still very low in young people. We’ve identified this risk because we want to know what’s causing the significant upward trend. Also, are we catching it early? Will it continue for decades to come? Our goal is to find the answers to those and other questions.”
Study limitations include a small proportion of patients with pancreatic cancer younger than age 55, and limited covariates and coding reliability in the SEER database, Dr. Gaddam said.
“Future studies should validate these findings in other large population-based cohorts,” he added. Dr. Gaddam’s research team currently is analyzing data derived from large national databases to evaluate trends.
The study authors concluded, “This study found that pancreatic cancer incidence increased among both sexes between 2000 and 2018. However, a greater relative increase was observed among women younger than age 55 years, especially among those aged 15 to 34 years. Even though the reason for this relative increasing trend among younger women is unclear, it may imply a sex-based disproportional exposure to known or unknown risk factors. The observed trend can offer clues to researchers to gain better insight into pathogenesis of pancreatic cancer.”
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
