Real-world treatment outcomes from nationwide ONCO-colon Turkey registry in RAS wi̇ld-type patients treated with biologics first-line metastatic colorectal cancer.
Authors: Kefeli Umut , Arslan Cagatay , Yildirim Mahmut Emre , Isikdogan Abdurrahman , Karadurmus Nuri , Karabulut Bulent , Cubukcu Erdem , Cicin Irfan , Yalçin Şuayib , Turk Haci M. , Bilir Cemil , Karaca Mustafa , Artac Mehmet , Sendur Mehmet Nahit , Alacacioglu Ahmet , Simsek Eda Tanrikulu , Dane Faysal , Bilici Ahmet , Cevik Duygu , Gumus Mahmut ,   Onco-Colon Turkey Registry Group
Published: June 2021

e15561 Background: Efficacy of anti-angiogenic and anti-EGFR agents has been demonstrated metastatic colorectal cancer (mCRC). Real-world evidence is especially important to detect the findings of patients outside of clinical trials. It complements together with clinical trials. However, there are a few studies that evaluated these treatments with biologics in the real-world setting. Recognizing the change that has occurred over the years will also shed light on future approaches. Therefore, we aimed to investigate the real-world data of patients with RAS-wild type mCRC. Methods: Medical records from 28 centers were collected for patients diagnosed with RAS wild-type mCRC between January 2016 and April 2019 and were included into the study. Histopathological, molecular and clinical characteristics of the patients were recorded. The treatment duration, response rate, progression-free survival and safety results were determined. Also, changes over the years were compared. Patients were compared according to the first-line biological treatments as anti-EGFR group (Group A and B) (panitumumab and cetuximab) and anti-VEGF group (group C). Results: Patients with KRAS mutant type were 43,6% and 6.1% patients were NRAS mutant type. A total of 1064 patients with documented RAS wild-type status were evaluated. 33%, 37% and 30% of all first line patients were treated with regimen including panitumumab, cetuximab and anti-VEGF, respectively. The median follow-up time was 24 (1-59) months. Median age was 61 (17-88) years. Thirty-five percent of the patients were female. Twenty percent of the patients had a right-sided colon tumor. Patients received median 6 cycles of treatment. Also, responded patients received median 6 cycles of treatment as maintenance treatment with biologics plus fluoropyrimidine. Overall response rate was 46,4%, 41,9% and 41,5% in A, B and C group respectively (p = 0,170). The median OS was 26, 27, and 23 months in A, B and C group respectively (p = 0.044). The median PFS of the patients in first-line setting that received panitumumab, cetuximab and bevacizumab were 11.6 (SE:0,6; 95% CI: 10.4-12.7), 11.0 (SE:0,5; 95% CI: 9.9-12.0), and 9.6 (SE:0,4; 95% CI: 8.8-10.4) months respectively (p = 0.012). In univariate analysis, female gender (p = 0.030), left sided tumors(p = 0.001), ECOG performance status (PS) 0-1 (p = 0.001), normal CEA level at initial diagnosis(p = 0.001) and treatment with anti-EGFR agents(p = 0.016) were found as favorable factors. PS 0-1 and normal CEA level at initial diagnosis were found as independent prognostic factors in multivariate analysis (p = 0.049, p = 0.031 respectively). Conclusions: This analysis of real-world data confirms the comparable efficacy of anti-EGFR agents in RAS-wild type mCRC. However, anti-EGFR treatment provides PFS and OS advantage when compared with anti-VEGF treatment in these patients.