Chemotherapy and bevacizumab prescription in routine management of metastatic colorectal cancer in Uruguay: Is clinical practice following the evidence?

Abstract

e15559 Background: Colorectal cancer (CRC) is the second leading cancer cause of death in Uruguay, with about 1000 deaths/year. Almost 25% of CRC patients present with disseminated disease, whereas recurrence occurs in up to 50% of those initially diagnosed at earlier stages. The introduction of targeted agents such as bevacizumab has improved the prognosis in stage IV CRC patients remarkably, becoming the current standard choice of systemic therapy. Universal access to bevacizumab is guaranteed in Uruguay since November 2008, financed by a governmental funding source for high-cost drugs and procedures. Emerging evidence on the optimal use of chemotherapy and biologics in patients with metastatic colorectal cancer (mCRC) must guide clinical practice. Objective: This study aims to assess real-world data on bevacizumab prescription in mCRC in an Uruguayan population to better understand treatment practice. Methods: A retrospective descriptive cohort study on individuals with CRC diagnosed and treated between 2009 and 2020, who received palliative chemotherapy at the National Cancer Institute of Montevideo. It included patients with newly diagnosed mCRC and patients who progressed/relapsed from initially diagnosed earlier-stage disease. We assessed the use of bevacizumab in addition to first-line chemotherapy. Multivariable logistic regression analyses were performed to calculate the predictors for the additional prescription of bevacizumab. Survival estimates were calculated using the Kaplan-Meier method, and the proportions were compared using the log-rank test. Results: Of a cohort of 907 patients, 233 stage IV or progressive/recurrent CRC patients were considered for analysis (mean age 61 years, 60% male). Bevacizumab was added to palliative chemotherapy in 134 patients (57%), representing 54% of those initially diagnosed mCRC and 65% of those treated for progressive or recurrent disease. Adding bevacizumab to palliative chemotherapy was associated with an improved median overall survival from 15.6 to 19.9 months. Results show that the likelihood of additional bevacizumab prescription to chemotherapy was significant for patients < 70 years (p < .001) and those with a colonic tumor versus a rectal one (OR 0.57; 95% CI, 0.32- 0.99). No statistically significant differences were found between right-sided and left-sided tumors (OR 0.68; 95% CI 0.37-1.27 p = 0.228). Bevacizumab prescription was significantly higher for patients who had their primary tumor resected (p = 0.006). Conclusions: In this real-world setting observational study on patients with mCRC treated throughout a 10-year period in Uruguay, the OS reported in those receiving additional bevacizumab to chemotherapy is consistent with that observed in previous studies, indicating the reproducibility of the results of pivotal studies in the Latin American context.