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