Comparison of gastric cancer survival between Caucasian and Asian patients treated in the United States: results from the Surveillance Epidemiology and End Results (SEER) database.

BACKGROUND

The prognosis for gastric cancer is better for Asian than for Caucasian patients. The primary driver of this difference is unknown. This study determined whether the survival advantage of Asian ethnicity continued to hold after control was used for other well-known prognostic factors.

METHODS

In this study, 12,773 patients who underwent gastrectomy for treatment of adenocarcinoma of the stomach were identified from the Surveillance, Epidemiology, and End Results cancer registry. Patients with cardia tumor were excluded from the study. The independent prognostic effect of ethnicity was evaluated by adjusting for other known factors.

RESULTS

The Asian patients tended to have a diagnosis at an earlier age (66.8 vs. 68.5 years), more lymph nodes examined (16 vs. 13), and more positive lymph nodes (5.1 vs. 4.8). Survival was better for the Asian patients than for the Caucasian patients, with a 12 % 5-year survival difference. Among the patients with IB, IIA, and IIB disease, the Asian patients had 37, 72, and 13 months longer median survival time than the corresponding Caucasian patients. The multivariate Cox model showed persistence of this result after adjustment for imbalances of age, gender, tumor grade, and number of examined and positive lymph nodes. The largest risk reduction was observed for the stage IA patients (31 %) and the smallest for the stage IIIC patients (9 %).

CONCLUSION

After excluding proximal gastric cancers, controlling for the imbalance of known prognostic factors, and decreasing in the influence of D2 lymphadenectomy, stage migration, and chemo/radiation therapy by including only patients treated in the United States, this study found that the survival advantage of Asian ethnicity continued to be present.