Gastric cancer is a severe malignancy associated with a poor prognosis that most commonly occurs in patients over the age of 70. Although gastric cancer is the third most common cancer in the United States, rates of this malignancy have been in decline in recent years due to increased understanding of risk factors and efforts to identify patients with precancerous disease. Despite this, a study published recently in Surgery found that gastric cancer is now occurring more commonly in younger adults. The study compared rates of gastric cancer in patients aged 20 to 59 to those aged ³60 as recorded in the Surveillance, Epidemiology and End Results (SEER) registry from 1973 to 2015 to determine clinical and genetic factors associated with early-onset gastric cancer.
Of the 75,225 cases of gastric cancer evaluated across the entire study period, 25% occurred in the younger population and 75% occurred in the traditional over-60 population. However, rates of gastric cancer in the 20 to 59-year population have increased by 1.5% a year from 1995 to 2013, and early-onset gastric cancer now accounts for more than 30% of new cases of gastric cancer in the United States. Gastric cancer occurring in younger patients is more likely to have a higher grade (55.2% vs 46.9%), signet-ring cells (19.0% vs 10.4%), diffuse histology (25.7% vs 15.0%), and be metastatic (49.5% vs 40.9%). Late-onset gastric cancer was more likely to be associated with microsatellite instabilities compared to early-onset cancer (18.6% vs 5.6%), while early-onset cancer was associated with Epstein-Barr virus. Standard risk factors associated with gastric cancer in the traditional population, including smoking and binge drinking, were no associated with increased rates of gastric cancer in the young adult population.
The investigators concluded that the incidence of early-onset gastric cancer is increasing in the United States and represents a clinically and genetically distinct subset of cancer compared to gastric cancer occurring in traditional populations. Future studies should focus on identifying risk factors for early-onset gastric cancer
Read more about this study on Medscape Medical News.