RESUMO
BACKGROUND: Both perioperative chemotherapy (PC) and adjuvant chemoradiotherapy (CRT) improve survival in resectable gastric cancer; however, these treatments have never been formally compared. Our objective was to evaluate treatment trends and compare survival outcomes for gastric cancer patients treated with surgery and either PC or CRT. METHODS: We performed a retrospective population-based cohort study between 2007 through 2013 using California Cancer Registry data. Patients diagnosed with stage IB-III gastric adenocarcinoma and treated with total or partial gastrectomy were eligible for this study. Based on the type of treatment received, patients were grouped into surgery-only, PC, or CRT. Primary and secondary outcomes were overall survival (OS) and gastric cancer-specific survival (GCCS) respectively. Mortality hazards ratios (HRs) for each of these outcomes were computed using propensity score weighted and covariate-adjusted Cox regression models, stratified by clinical node status. RESULTS: Of 2,146 patients who underwent surgical resection, 1,067 had surgery-only, while 771 and 308 received PC or CRT, respectively. Median OS was 25, 33, and 52 months for surgery-only, PC, and CRT, respectively; P<0.001. Overall, patients treated with PC had significantly poorer survival compared to CRT (HR =1.45; 95% CI: 1.22-1.73). PC was also associated with higher mortality in patients with signet ring histology (HR =1.66; 95% CI: 1.21-2.28) and clinical node negative cancer (HR =1.85; 95% CI: 1.32-2.60). Survival was not different between PC vs. CRT in clinical node positive patients (HR =1.29; 95% CI: 0.84-2.08). Of note, the percentage of patients receiving PC increased from 17.5% in 2007-2008, to 41.5% in 2013-2014; P<0.001. CONCLUSIONS: Despite the rapid adoption of PC, overall, CRT is associated with better survival than PC. Specifically, clinical node negative and signet ring histology patients had better survival when treated with CRT compared to PC. Based on these findings, we recommend against indiscriminate adoption of PC and consideration for CRT over PC in clinical node negative patients.
RESUMO
IMPORTANCE: Cancer center recognition, offered as accreditation by the American College of Surgeons Commission on Cancer or the National Cancer Institute, and quality measure reporting purport to improve the quality of cancer care. For surgically resectable gastric cancer, removal of 15 or more lymph nodes has been associated with improved outcomes and has been endorsed as a gastric cancer quality measure. OBJECTIVES: To determine whether cancer center classification is associated with compliance with the lymph node-count quality measure and the effect of compliance with the measure on overall survival. DESIGN, SETTING, AND PARTICIPANTS: A retrospective review of prospectively collected population-based data from the Surveillance, Epidemiology, and End Results Cancer Registry of Greater California and California Cancer Registry was conducted. Participants included patients who underwent surgery for stage I to III gastric adenocarcinoma between January 1, 2004, and December 31, 2010. MAIN OUTCOMES AND MEASURES: Compliance with removal of 15 or more lymph nodes and overall survival. RESULTS: Of 3321 gastric cancer cases, 42.3% had a minimum of 15 lymph nodes removed. Hospitals with cancer program recognition treated 69.9% of the cases. In hospitals without cancer program approval, 34.8% of the patients had 15 or more lymph nodes removed compared with 45.5% in the facilities with cancer program approval. Logistic regression analysis demonstrated that patients undergoing gastrectomy had significantly higher odds of having 15 or more lymph nodes removed if they were younger (trend P < .001), Asian/other race/ethnicity (adjusted odds ratio [AOR], 1.24; 95% CI, 1.03-1.50), or non-Hispanic black (AOR, 1.37; 95% CI, 1.03-1.82) compared with non-Hispanic white, received diagnosis at a progressively higher stage (trend P < .001), or received diagnosis in a more recent year (trend P < .001). Removal of 15 or more lymph nodes was associated with cancer program recognition (vs no recognition) (odds ratio, 1.48; 95% CI, 1.25-1.74). Cox proportional hazards regression showed that improved survival was predicted by removal of 15 or more lymph nodes (hazard ratio [HR], 0.70; 95% CI, 0.63-0.78) but not by cancer program recognition (HR, 1.03; 95% CI, 0.92-1.15). CONCLUSIONS AND RELEVANCE: Although adequate lymph node retrieval is more likely in hospitals with a recognized cancer program, survival outcome is associated with the lymph node count rather than with cancer program classification. Less than half of the cases reviewed in this study met the minimum lymph node-count guideline, indicating the need for process improvement for all hospitals.
