Baseline treatment patterns of the first 277 patients in PROMETCO: A real-world, prospective, longitudinal cohort study on the continuum of care in metastatic colorectal cancer (mCRC).

Abstract

55 Background: Tumor shrinkage and disease control with preservation or improvement in quality of life are the primary treatment goals for patients with unresectable mCRC. When not possible, emphasis lies in slowing disease progression and prolonging survival. Advances in mCRC treatment have now improved survival to an average of 30 months in clinical trials. Here, we present initial baseline treatment patterns from the PROMETCO study (NCT03935763), the first international, prospective real-world study to investigate the continuum of care in the mCRC population, collecting data on all patients regardless of treatment. Methods: Enrolment in PROMETCO began in March 2019. On October 1, 2020, systemic treatment characteristics from 277 mCRC patients were analyzed. Adult patients with two disease progressions since the first diagnosis of metastatic disease who were willing to receive subsequent treatment were included. Treatments started prior to study inclusion were analyzed by line and by patients’ molecular status (RAS/BRAF and MSI). Results: In the overall population, first-line treatment data were available for 257 patients. Doublet/triplet chemotherapy (dt/t CT) + anti-VEGF/EGFR therapy was received by 70% (180) of patients, and 20% (51) received dt/t CT alone, in contrast to current guidelines. At second line (n = 209), 68% (142) of patients received dt/t CT + anti-VEGF/EGFR therapy. The proportion of dt/t CT given alone was consistent between first and second line. Median duration of treatment decreased with progressing line of treatment (mirrored in the molecular status subgroups). In the RAS/BRAF patient population, 14% (40) had unknown status at inclusion, 0.7% (2) were RAS/BRAF mutant (mut), and the BRAF mut subgroup had too few numbers from which to draw conclusions. The proportion of patients receiving dt/t CT alone was higher in the RAS mut (23%; 31/135) vs RAS/BRAF WT (12%; 9/76) groups. Dt/t CT + anti-VEGF was received by 64% (87/135) and 21% (16/76) of the RAS mut and RAS/BRAF WT patients, respectively. There were no unexpected results in treatments received between molecular groups at second line, nor in terms of the length of treatment. Fifty percent of the population had unknown MSI status, and MSI low/high groups had too few numbers from which to draw conclusions. The treatment distribution in MSS patients at first line (n = 124) and second line (n = 102) followed a similar trend to the overall population. Conclusions: Preliminary data from PROMETCO provide key insights as to the treatments received by real-world mCRC patients. Further analysis of patients in a larger cohort will be important to better understand discrepancies in treatment choice (ie adherence to guidelines), and country-based differences in testing/reimbursement, which may help elucidate the missing data seen in the molecular-status subgroups. Clinical trial information: NCT03935763.