Dataset Information

Survival trends of patients with non-metastatic gastric adenocarcinoma in the US and European countries: the impact of decreasing resection rates.

ABSTRACT:

Background

We previously observed decreasing resection rates of non-metastatic gastric adenocarcinoma (GaC) in the US and some European countries. If and to what extent these trends affect the trends in overall survival (OS) of patients with non-metastatic GaC at the population level remain unclear. This large international population-based cohort study aimed to assess the impact of the previously observed decreasing resection rates on multivariable-adjusted trends in the long-term OS of patients with non-metastatic GaC.

Methods

Individual-level data of patients with non-metastatic GaC were obtained from the national cancer registries of the Netherlands, Belgium, Sweden, Norway, and Slovenia, and the US Surveillance, Epidemiology, and End Results database. We analyzed data for each country separately. Associations between year of diagnosis and OS were assessed using Cox proportional hazards regression model with adjustment for multiple prognostic variables, with and without including resection and chemotherapy as potential explanatory variables.

Results

A total of 66,398 non-metastatic GaC patients diagnosed in 2003-2016 were analyzed, with an accumulated follow-up of 172,357 person-years. Without adjustment for resection, OS was improved only slightly in the US [hazard ratio (HR)_{per year} = 0.99; HR_≥ _vs. _<2010 = 0.96], and no improvement was observed in the investigated European countries, with OS even worsening in Sweden (HR_{per year} = 1.03; HR_≥ _vs. _<2010 = 1.17). After adjusting for resection, the increasing OS trend became stronger in the US (HR_{per year} = 0.98; HR_≥ _vs. _<2010 = 0.88), and the temporal trend became insignificant in Sweden. In Slovenia (HR_{per year} = 0.99; HR_≥ _vs. _<2010 = 0.92) and Norway (HR_{per year} = 0.97; HR_≥ _vs. _<2010 = 0.86), improved OS over time emerged after resection adjustment. Improved OS in patients undergoing resection was observed in the US, the Netherlands, and Norway. Adjustment for chemotherapy did not alter the observed associations. Stratified analyses by tumor location showed mostly similar results with the findings in all patients with non-metastatic GaCs regarding the associations between year of diagnosis and survival.

Conclusions

OS of patients with non-metastatic GaC mostly did not improve in selected European countries and was even worsened in Sweden, while it was slightly increased in the US in the early 21^st century. Progress in OS of patients with non-metastatic GaC seems to have been impeded to a large extent by decreasing rates of resection.

SUBMITTER: Huang L

PROVIDER: S-EPMC9257984 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:BackgroundResection is the cornerstone of curative treatment for many nonmetastatic gastric cancers (GCs), but the population treatment patterns remains largely unknown. This large international population-based study aimed at investigating the treatment patterns and trends for nonmetastatic GC in Europe and the United States and at exploring factors associated with resection.MethodsData of patients with microscopically confirmed primary invasive GC without distant metastasis from the national cancer registries of the Netherlands, Belgium, Sweden, Norway, Slovenia, and Estonia and the US Surveillance, Epidemiology, and End Results (SEER)-18 Program were retrieved. Age-standardized treatment rates were computed and trends were evaluated using linear regression. Associations of resection with patient and tumor characteristics were analyzed using multivariable-adjusted log-binomial regression. Analysis was performed in each country respectively without pooling.ResultsTogether 65 707 nonmetastatic GC patients diagnosed in 2003-2016 were analyzed. Age-standardized resection rates significantly decreased over years in all countries (by 4-24%). In 2013-2014, rates varied greatly from 54 to 75%. Patients with increasing ages, cardia cancers, or cancers invading adjacent structure were significantly less frequently resected. Resection was further associated with sex, performance status, comorbidities, tumor histology, tumor size, hospital type, and hospital volume. Association patterns and strengths varied across countries. After multivariable adjustment, resection rates remained decreasing (prevalence ratio = 0.97-0.995 per year), with decreasing trends consistently seen in various subgroups.ConclusionsNonmetastatic GCs were less frequently resected in Europe and the United States in the early 21st century. Resection rates varied greatly across countries and appeared not to be optimal. Various factors associated with resection were revealed. Our findings can help to identify differences and possibly modifiable places in clinical practice and provide important novel references for designing effective population-based GC management strategies. In Europe and the United States, nonmetastatic gastric cancers were less frequently resected in the early 21st century. Resection rates varied greatly across countries and appeared not optimal. Various factors associated with resection were revealed. Our findings identify differences and possibly modifiable places in clinical practice and provide important novel references for designing effective population-based management strategies.