Adherence to clinical practice guidelines for adjuvant chemotherapy for colorectal cancer in Uruguay: A population-based study.

53 Background: Despite surgery, the 5-year risk of systemic recurrence of colorectal cancer (CRC) in the absence of any further therapy is approximately 50 % for those with lymph node involvement and 20 ─ 30 % if the lymph nodes are negative. Adjuvant chemotherapy contributes to improved disease-free and overall survival for node-positive (stage III) or high-risk node negative (stage IIB) colon cancer. Similar benefits are observed for adjuvant chemoradiotherapy in rectal cancer. Previous research shows varied rates of adherence to published adjuvant chemotherapy Clinical Practice Guidelines (CPGs) for CRC, although population-based data is scarce. Purpose: The aim of this analysis was to assess adherence rates to adjuvant chemotherapy prescription within 16 weeks of surgery according to local and international CPGs for CRC patients treated with curative intent between 2008 and 2019 at the Uruguayan National Cancer Institute. Data regarding factors associated with chemotherapy receipt beyond 16 weeks from surgery and chemotherapy non receipt was also retrieved and analysed. Methods: We retrospectively reviewed medical and pathology reports of 833 patients diagnosed with CRC at our institution. Patients with stages IIB or III CRC who underwent curative-intent surgery were identified and included in the present analysis. A 16-week benchmark timeline for treatment initiation from date of surgery was considered. Fisher’s exact test was used to determine factors independently associated with receipt of chemotherapy and meeting the 16-week benchmark (p 0.05). Results: A total of 400 patients were identified of which 72% had peritoneal colorectal tumors and 28% had sub-peritoneal rectal tumors. Approximately 70% of the latter group received neoadjuvant chemo-radiotherapy. Considering the total cohort, 61% received adjuvant chemotherapy. Factors predicting chemotherapy receipt in the peritoneal colorectal group were age ≤ 70 and stage III disease. In the sub-peritoneal rectal group no significant effect was found. The 16-week benchmark was met in 72% (175) of those receiving chemotherapy and 70.6% (167) completed 6 months of systemic adjuvant treatment. A total of 156 patients (39%) did not receive adjuvant chemotherapy. The factors predicting chemotherapy non receipt were age > 70 and stage IIB in the peritoneal colorectal group. Conclusions: This analysis of adherence to CPGs identified several factors associated with chemotherapy non receipt and chemotherapy receipt outside of timeline benchmarks from date of curative-intent surgery in Montevideo, Uruguay. The two main factors significantly associated with chemotherapy non receipt were advanced age and lower disease stage. To our knowledge, our data is the first to elucidate these specific factors in the Uruguayan CRC patient population.