Prospective evaluation of current RAS mutation testing practices in newly diagnosed metastatic colorectal cancer: Middle East and North Africa Registry (MORE-RAS) Study

Autor: A. A. Alsharm, Linah Basir, Bouzid Kamel, Amr A. Elsaid, Hassen Mahfouf, Assia Ouamer, Mohammed Oukkal, Larbaoui Blaha, Adda Bounedjar, Abdelsalam Alnajjar, Fouad Abu-Taleb
Rok vydání: 2020
Předmět:
Zdroj: Journal of Clinical Oncology. 38:e16141-e16141
ISSN: 1527-7755
0732-183X
Popis: e16141 Background: RAS testing is essential for treatment selection in metastatic colorectal cancer (mCRC), as anti-EGFR treatment is indicated only in patients with wild-type (WT) RAS. MORE-RAS was a multicenter, multicountry, observational, ambispective (retrospective + prospective) study designed to evaluate RAS mutation status among patients with mCRC in the Middle East and North Africa (MENA) region. Results of the retrospective study over a prior 2-year period have been previously presented. Here, we report on the prospective evaluation of testing practices in newly diagnosed patients from the same centers. Methods: Five countries (Algeria, Egypt, KSA, Kuwait, Lebanon) enrolled patients between Dec 2014 and Feb 2019. Patients with a new diagnosis of histologically proven mCRC, at least 1 measurable lesion per RECIST criteria, and tissue availability for biomarker analysis were included; those with co-existing malignancies or life expectancy < 6 months were excluded. The primary endpoint was evaluation of the rate of RAS mutation in newly diagnosed patients. Follow-up was for 2 years. Results: 500 patients (mean age 54.6 years; 58% female) were included; 96.4% had Stage 4 disease. Primary tumor sites were sigmoidal colon: 33.4%; rectum: 29.6%; ascending colon: 18.4%; descending colon: 11.4%; transverse colon: 5.2%; and unknown: 1.4%. Most frequent sites of metastasis were liver: 43.4%, lung: 16.0%, and peritoneum: 10.1%. Overall, 407 pts (81.4%; 95% CI, 78%–85%) received prescription for RAS testing. RAS WT was found in 58.4% and mutant in 41.6%; the test was inconclusive in 1 pt. Non-prescription was attributed to test unavailability and medical or financial reasons. The distribution of mutations was KRAS: 85%, NRAS: 4.9%, and not available: 10.1%. Predictors of RAS testing prescription were older age, primary tumor localization in ascending colon, and high tumor grade. Knowledge of RAS status resulted in the addition of bevacizumab or anti-EGFR therapy in 20.4% and 21.2% of pts, respectively at Visit 1 (baseline). Conclusions: RAS testing is now routinely prescribed for newly diagnosed mCRC in the MENA region and can change therapy patterns. The RAS mutation rate in this region differs from that in Western countries.
Databáze: OpenAIRE