Predictors of Nonadherence to NCCN Guideline Recommendations for the Management of Stage I Anal Canal Cancer.

ABSTRACT

Background: Definitive chemoradiotherapy (CRT) is recommended by the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Anal Carcinoma for all patients with stage I anal canal cancer. Because these patients were not well represented in clinical trials establishing CRT as standard therapy, it is unclear whether NCCN recommendations are being closely followed for stage I disease. This study identified factors that predict for NCCN Guideline-concordant versus NCCN Guideline-discordant care. Methods: Using the National Cancer Data Base, we identified patients diagnosed with anal canal carcinoma from 2004 to 2012 who received concurrent CRT (radiotherapy [RT] 45.0-59.4 Gy with multiagent chemotherapy), RT alone (45.0-59.4 Gy), or surgical procedure alone (local tumor destruction, tumor excision, or abdominoperineal resection). Demographic and clinicopathologic factors were analyzed using the chi-square test and logistic regression modeling. Results: A total of 1,082 patients with histologically confirmed stage I anal cancer were identified, among whom 665 (61.5%) received CRT, 52 (4.8%) received RT alone, and 365 (33.7%) received only a surgical procedure. Primary analyses were restricted to patients receiving CRT or excision alone, as these were most common. Multivariable analysis identified factors independently associated with reduced odds of CRT receipt low versus intermediate/high tumor grade (adjusted odds ratio [AOR], 0.21; 95% CI, 0.14-0.29; P<.001), tumor size <1 cm vs 1 to 2 cm (AOR, 0.24; 95% CI, 0.17-0.35; P<.001), age ≥70 versus 50 to 69 years (AOR, 0.36; 95% CI, 0.24-0.54; P<.001), male sex (AOR, 0.63; 95% CI, 0.45-0.90; P=.009), and treatment at an academic versus a non-academic facility (AOR, 0.58; 95% CI, 0.41-0.81; P=.002). Conclusions: Despite the NCCN recommendation of CRT for stage I anal cancer, at least one-third of patients appear to be receiving guideline-discordant management. Excision alone is more common for patients who are elderly, are male, have small or low-grade tumors, or were evaluated at academic facilities.