Surgeon proficiency gain and survival after gastrectomy for gastric adenocarcinoma: A population-based cohort study.

Objective: Quality of surgery is essential for survival in gastric adenocarcinoma, but studies examining surgeons' proficiency gain of gastrectomies are scarce. This study aimed to reveal potential proficiency gain curves for surgeons operating patients with gastric cancer.

Methods: Population-based cohort study of patients who underwent gastrectomy for gastric adenocarcinoma in Sweden between 2006 and 2015 with follow-up throughout 2020. Data were retrieved from national registries and medical records. Risk prediction models were used to calculate outcome probabilities, and risk-adjusted cumulative sum curves were plotted to assess differences (change points) between observed and expected outcomes. The main outcome was long-term (>3-5 years) all-cause mortality after surgery. Secondary outcomes were all-cause mortality within 30 days, 31-90 days, 91 days to 1 year and>1-3 years of surgery, resection margin status, and lymph node yield.

Results: The study included 261 surgeons and 1636 patients. The>3- to 5-year mortality was improved after 20 cases, and decreased from 12.4% before to 8.6% after this change point (p = 0.027). Change points were suggested, but not statistically significant, after 22 cases for 30-day mortality, 28 cases for 31- to 90-day mortality, 9 cases for 91-day to 1-year mortality, and 10 cases for>1- to 3-year all-cause mortality. There were statistically significant improvements in tumour-free resection margins after 28 cases (p < 0.005) and greater lymph node yield after 13 cases (p < 0.001).

Conclusions: This study reveals proficiency gain curves regarding long-term survival, resection margin status, and lymph node yield in gastrectomy for gastric adenocarcinoma, and that at least 20 gastrectomies should be conducted with experienced support before doing these operations independently.