Gastric Cancer Incidence Increasing in Younger Population in Latin America

The incidence of gastric cancer in younger people increased substantially over a 12-year period in Latin America, according to a new study. The increase was seen primarily in young women, who often presented with more advanced disease.

“Gastric cancer has been considered a disease of the older population worldwide,” wrote study authors led by Germán Calderillo-Ruiz, MD, of the National Cancer Institute in Tlalpan, Mexico. He presented results of the new retrospective, observational study at the European Society for Medical Oncology (ESMO) World Congress on Gastrointestinal Cancer 2019, held July 3-6 in Barcelona, Spain.

The study included a total of 2,022 patients with gastric adenocarcinoma, treated between 2004 and 2016 at INCAN Mexico. Of that total, 290 patients (14%) were 40 years of age or under; of those younger patients, 54% were women. The mean age of both women and men among the younger patients was 34.6 years. The study found a 120% increase over the 12-year study period of patients aged 40 years or younger.

Most of the primary tumors in this younger cohort were gastric (93%), followed by the esophagogastric junction (7%). Most patients presented with stage IV disease (76%), followed by 16% with locally advanced disease and 8% with stage I–III gastric cancer.

Compared with men, women presented with higher rates of poor prognostic factors. A total of 68% of women had diffuse-type histology compared with 32% of men (P = 0.127); more women had ring-seal cells (76% vs 69%; P = 0.049), poorly differentiated gastric cancer (89% vs 84%; P = 0.014), and were more likely to present with stage IV disease (59% vs 41%; P = 0.011).

The median overall survival (OS) for the women in the study was 7 months, compared with 8 months for men, for a hazard ratio of 1.29 (95% CI, 1.05–1.65; P = 0.030). The median OS was longer for patients with esophagogastric junction tumors than with gastric tumors.

A multivariate analysis found that gender was an independent predictor of overall survival, with an HR of 1.29 (95% CI, 1.01–1.65; P = 0.038). Primary tumor site and clinical stage at presentation were also independent predictors of survival, while histology was not significantly associated.

“The lack of financial resources may impact on women’s behaviour of delaying pursuit of medical care when gastric symptoms appear,” Calderillo-Ruiz said. “We hope this research will encourage clinicians and patients to be more aware of the risk of gastric cancer in younger people and, in particular, to encourage women with gastric symptoms to seek medical help sooner.”

Rodrigo Dienstmann, MD, of Vall d’Hebron Institute of Oncology in Barcelona, who commented on the study for ESMO, noted the combination of genetic and environmental factors that go into the development of gastric cancer.

“We cannot change the genetic factors, but we can act on the unhealthy diet, obesity, and untreated Helicobacter pylori infection which increase the risk of gastric cancer,” he said. “Helicobacter infection can cause chronic inflammation and lesions that are precursors to gastric cancer but, once diagnosed, can be cured with a combination of antibiotics and drugs to reduce stomach acid.”

He stressed that younger people who regularly experience heartburn or other gastric symptoms should consult a physician, while clinicians should be aware that gastric cancer is not uncommon among younger individuals.