Early-Onset Gastric Cancer Suggested to be Genetically and Clinically Distinct

Early-onset gastric cancer is genetically and clinically distinct from traditional gastric cancer, according to a study published in the journal Surgery.¹

With the incidence of early-onset gastric cancer steadily increasing in the US since 1995, comprising >30% of new gastric cancer cases today, researchers indicated that additional investigations are crucial to better understand this startling finding and to facilitate optimal treatment and surveillance strategies.

“I think this is an alarming trend, as stomach cancer is a devastating disease,” senior author Travis Grotz, MD, surgical oncologist at the Mayo Clinic, said in a press release.² “There is little awareness in the US of the signs and symptoms of stomach cancer, and many younger patients may be diagnosed late – when treatment is less effective.” 

In this cohort of 75,225 cases studied from 1972 to 2015 using several cancer databases, researchers found that the incidence of late-onset stomach cancer decreased by 1.8% annually over the course of the study period, while early-onset gastric cancer decreased annually by 1.9% from 1973 to 1995 and then increased by 1.5% through 2013.

Early-onset gastric cancer was correlated with higher grade (55.2% vs 46.9%), signet-ring cells (19.0% vs 10.4%), diffuse histology (25.7% vs 15.0%), and metastatic disease (49.5% vs 40.9%, all P < 0.01). Additionally, early-onset gastric cancer was more likely to be Epstein-Barr virus (7.7% vs 5.1%) or genomically stable (22.5% vs 8.1%) subtype, whereas late-onset gastric cancer was more likely to be microsatellite instability subtype (18.6% vs 5.6%; all P < 0.01). Risk factors for gastric cancer were associated less with early-onset gastric cancer compared with late-onset gastric cancer. 

The average age of someone diagnosed with stomach cancer today is 68, according to the American Cancer Society, however individuals in their 30s, 40s, and 50s are more at risk now than they used to be.³“Typically, we see stomach cancer being diagnosed in patients in their 70s, but increasingly we are seeing 30- to 50-year-old patients being diagnosed,” Grotz said. 

The increased rate of the early-onset disease is not due to earlier detection or screening, according to the researchers. Moreover, traditionally associated risk factors for developing gastric cancer among older adults, such as smoking and binge drinking, were not correlated with early-onset patients.

“Hopefully studies like this will raise awareness and increase physician suspicion of stomach cancer, particularly in younger patients,” Grotz said. Younger patients who feel full before finishing a meal, or have reflux, abdominal pain, unintentional weight loss, and difficulty eating should see their healthcare provider, he added. 

The American Cancer Society estimates that in the US, 27,600 new cases of stomach cancer (16,980 in men and 10,620 in women) will diagnosed in 2020. 

The research team next hopes to better identify risk factors for early-onset gastric cancer.

References:

1. Bergquist JR, Leiting JL, Habermann EB, et al. Early-onset gastric cancer is a distinct disease with worrisome trends and oncogenic features. Surgery. doi:10.1016/j.surg.2019.04.036.

2. Many younger patients with stomach cancer have a distinct disease, Mayo research discovers [news release]. Rochester, Minnesota. Published December 24, 2019. newswise.com/articles/many-younger-patients-with-stomach-cancer-have-a-distinct-disease-mayo-research-discovers?sc=mwhr&xy=10024642. Accessed January 17, 2020.

3. American Cancer Society. Key Statistics About Stomach Cancer. American Cancer Society website. Published January 8, 2020. cancer.org/cancer/stomach-cancer/about/key-statistics.html. Accessed January 17, 2020.