Background: Westernization of lifestyle and diet has resulted in an increase in overweight patients in Japan. Although the adverse effects of higher body mass index (BMI) on early surgical outcomes are known, the relationship between BMI and long-term outcome is unclear.
Materials and methods: Clinicopathological characteristics and 5-year survival rate of overweight (BMI >or= 25 kg/m2; H-BMI; n = 1126) and nonoverweight (BMI < 25 kg/m2; N-BMI; n = 6799) patients who underwent gastrectomy with curative intent at the Cancer Institute Hospital between 1970 and 2004 were compared.
Results: Patients in the H-BMI group tended to have earlier-stage disease. The 5-year survival rate was significantly better in the H-BMI than N-BMI group (81.5% vs 74.1%, respectively; P < .001). Postoperative mortality was 1% in both groups (P = .482), whereas postoperative morbidity was 22% and 19% in the H-BMI and N-BMI groups, respectively (P = .007). Multivariate analysis indicated overweight, age, gender, surgical procedure, histology, operation year, pT, and pN as independent prognostic factors. Subset analyses of pT and pN stages revealed overweight as an independent prognostic factor in patients with pT1 and pN0.
Conclusion: The 5-year survival rate following curative gastrectomy is better in overweight than nonoverweight Japanese patients, especially for early-stage gastric cancer. Further studies are needed to determine whether these results apply to other countries where morbidity and mortality for gastric cancer are higher than in Asian countries.