Early-onset gastric cancer, distinct from traditional disease, on the rise in US
Incidence of early-onset gastric cancer that is clinically and genetically distinct from late-onset disease has increased steadily in the United States, an “alarming phenomenon” that warrants further research, according to a study published in Surgery.
“There is an increasing trend of young patients diagnosed with gastric cancer, but without any of the traditional risk factors of gastric cancer. We wanted to find out why we are seeing this and what we might be able to do about it,” Travis E. Grotz, MD, surgical oncologist at Mayo Clinic in Rochester, Minnesota, told Healio.
Although the average age of stomach cancer diagnosis is 68 years, younger individuals have a higher risk for the disease than in the past, researchers noted in a press release.
Grotz and colleagues analyzed data from the SEER database, Behavioral Risk Factor Surveillance Survey and The Cancer Genome Atlas to identify clinical and genomic characteristics and risk factors of early-onset gastric cancer (n = 18,608) compared with late-onset gastric cancer (n = 56,617).
Results showed incidence of early-onset gastric cancer increased 1.5% annually between 1995 and 2013 (P < .05), whereas incidence of late-onset gastric cancer declined by 1.8% annually during the study period. The proportion of gastric cancers that were early-onset also increased significantly, from 18.4% in 1990 to more than 30% in each year since 2012 (P < .05).
When the researchers analyzed incidence using an age cutoff of 40 years, they observed an increase in early-onset disease from 1.7% in 1973 to 3.5% in 2015. With an age cutoff of 50 years, incidence decreased moderately from 7.6% in 1973 to 6% in 1982, then increased to 12.5% in 2015.
Those with early-onset gastric cancer appeared more likely to be male (66.9% vs. 61.1%) and nonwhite (31.6% vs. 23.2%), and have poorly differentiated histologic grade (55.2% vs. 46.9%), metastatic disease (49.5% vs. 40.9%), diffuse histology (25.7% vs. 15%) and signet-ring cells (19% vs. 10.4%; P < .01 for all).
Moreover, early-onset gastric cancer was more likely to be a genomically stable (22.5% vs. 8.1%) or an Epstein-Barr virus (7.7% vs. 5.1%) subtype. Conversely, late-onset gastric cancer appeared more likely to be a microsatellite instability subtype (18.6% vs. 5.6%).
“Molecular subtypes are going to be of increasing importance in the treatment of gastric cancer,” Grotz told Healio. “Unfortunately, we found young patients were less likely to have microsatellite instability tumors that may be responsive to immunotherapy, and were more likely to have a chemotherapy-resistant, genomically stable subtype. Further research is needed to determine the best perioperative treatment for these young patients.”
Common risk factors for gastric cancer, such as smoking and binge drinking, correlated less with early-onset gastric cancer than late-onset disease, according to the researchers.
“We plan next to use the Rochester Epidemiology Project — a unique population-based database of Southeast Minnesota and Northeast Wisconsin over the past 50 years — to determine what, if any, risk factors may contribute to early-onset gastric cancer,” Grotz told Healio. “We also plan to retrospectively evaluate recurrence patterns, pathologic response and survival according to the molecular subtype of gastric cancer to determine if choice of perioperative chemotherapy or chemoradiation should be determined by age or molecular subtype.” – by Jennifer Southall
For more information:
Travis E. Grotz, MD, can be reached at Mayo Clinic, 200 First St. SW, Rochester, MN 55905; email: email@example.com.
Disclosures: The authors report no relevant financial disclosures.