Patterns of Care for Radiotherapy in the Neoadjuvant and Adjuvant Treatment of Gastric Cancer: A Twelve-Year Nationwide Cohort Study in Korea

PURPOSE: Although Korea has the highest incidence of gastric cancer worldwide and D2-lymphadenectomies are routinely performed, radiotherapy (RT) practice patterns have not been well studied. Therefore, we examined RT usage trends for neoadjuvant/adjuvant patients and identified factors associated with RT. We also examined survival benefits and net medical cost advantages of adding RT. MATERIALS AND METHODS: Patients diagnosed with gastric cancer who underwent gastrectomy from 2002-2013 were identified using National Health Insurance Service-National Sample Cohort. RESULTS: Annually, 30.9 cases per 100,000 population in crude rate underwent gastrectomy in 230 hospitals and 49.8% received neoadjuvant/adjuvant therapy in 182 hospitals. For neoadjuvant/adjuvant patients, postoperative chemo-RT was administered in 4% of cases in 26 hospitals. No significant trends regarding treatment type were observed over time. Having undergone RT was inversely associated with being ≥ 60 years old and having a low income. Having undergone RT was positively related to having a Charlson comorbidity index ≥ 4, hospital location and hospital volume (≥ 2,000 beds). Significant portions of patients treated with RT in this nation (52%) were concentrated in one large-volume hospital. Use of RT linked to increased cost of primary treatment, yet not to reduced overall medical expense. RT did not influence both on overall and disease-specific survivals after adjusting for potential confounders (p > 0.05). CONCLUSION: RT was uncommonly utilized as adjuvant or neoadjuvant treatment by physicians in Korea. Despite intrinsic drawback in this data, we did not find either survival benefit or net medical cost advantage by adding RT in adjuvant treatment.