Treatment of appendiceal adenocarcinoma in the United States: penetration and outcomes of current guidelines.

Current treatment guidelines for appendiceal adenocarcinoma specify that right hemicolectomy should be performed. This study evaluates appendiceal cancer outcomes in the United States and treatment guideline compliance. Data for patients diagnosed with appendiceal adenocarcinoma in the Surveillance, Epidemiology, and End Results database (1988 to 2003) were analyzed. The 2511 patients with appendiceal adenocarcinoma had an average age of 59.3 years, average tumor size of 4.05 cm, and 5-year survival rate of 57 per cent. The 5-year survival rate by stage was statistically different (P < 0.001): Stage 0, 95.7 per cent; Stage I, 88 per cent; Stage II, 75.2 per cent; Stage III, 37.1 per cent; and Stage IV, 25.6 per cent. Appendectomy was performed in 33.4 per cent, which does not follow the current guidelines. In this group, 5-year survival was significantly less for patients with Stage III and IV disease (48% vs. 38.2%, P = 0.03; 46% vs. 26.4%, P = 0.04, respectively). Patients with Stage I and II disease had similar 5-year survival for appendectomy and colectomy (90.2% vs. 90.1%, P = 0.7; 78.3% vs. 76%, P = 0.6, respectively). One-third of patients with adenocarcinoma did not undergo current surgical guideline therapy. However, it appears hemicolectomy only improved survival for patients with later-stage disease. The current data raise the question of whether Stage I and II appendiceal cancer can be adequately treated with simple appendectomy.