Survival among patients cured from gastric adenocarcinoma compared to the background population.

Background: It is unknown if gastric adenocarcinoma survivors have longer, shorter, or similar survival compared to the background population. This knowledge could contribute to evidence-based monitoring strategies, healthcare recommendations, and information for patients and families.

Methods: This population-based cohort study included all patients who underwent gastrectomy for gastric adenocarcinoma between 2006-2015 in Sweden and survived ≥ 5 years after surgery. They were followed up until death, postoperative year 10, or end of study period (31 December, 2020). Division of the observed by the expected survival yielded relative survival rates with 95% confidence intervals (CIs) using the life table method. The expected survival was derived from the entire Swedish population of the corresponding age, sex, and calendar year. Data came from medical records and nationwide registers.

Results: The survival among all 767 gastric adenocarcinoma survivors was shorter than the expected. The reduction in relative survival increased for each follow-up year, from 97.3% (95% CI 95.4-99.1%) year 6 to 86.6% (95% CI 82.3-90.9%) year 10. The decline in relative survival was more pronounced among patients who had gastrectomy in earlier calendar years (82.9% [95% CI 77.4-88.4%] year 10 for years 2011-2015), shorter education (85.2% [95% CI 77.4-93.0%] year 10 for education ≤ 9 years), more comorbidities (78.0% [95% CI 63.9-92.0%] year 10 for Charlson comorbidity score ≥ 2), and no neoadjuvant therapy (83.2% [95% CI 77.4-89.0%] year 10).

Conclusion: Gastric adenocarcinoma survivors seem to have poorer survival than the corresponding background population, particularly in certain subgroups.