Implementation of universal, pan-cancer germline genetic testing in patients with cancer in Jordan.

Abstract

10580 Background: Detection of pathogenic germline variants (PGVs) has a significant and growing impact on the management of patients with many types of cancer. Most research to date evaluated individuals of European background, which can result in skewed genetic testing criteria and variant interpretation. Additional data are needed from diverse populations. This study aimed to investigate a universal germline testing strategy and the pattern and frequency of PGVs among all newly diagnosed cancer patients at a single center in Jordan. Methods: In this prospective, observational study, consecutive patients newly diagnosed with cancer were classified as meeting or not meeting National Comprehensive Cancer Network (NCCN) germline genetic testing criteria. All patients underwent an 84-gene panel test, independent of age, stage or family history. Demographics and clinical history were collected and analyzed from information provided by the clinicians on the test requisition form. Descriptive statistics were employed, and statistical significance was determined by two-tailed Fisher’s exact test and unpaired t test. Results: In total, 1377 cancer patients of Arabic background were enrolled, of which 831 (60.3%) met NCCN criteria (Table). PGVs were identified in 210 (15.3%). Excluding the 29 patients who were carriers for autosomal recessive conditions, 192 PGVs were identified in 181 (13.1%) patients. PGVs were most commonly identified in APC (p.I1307K variant, 55, 28.6%), BRCA2 (35, 18.2%), BRCA1 (21, 10.9%), and TP53 (12, 6.3%). While patients who met NCCN testing criteria were more likely to have a PGV (p<0.0001), 44 (24.30%) patients with PGVs did not meet criteria. Among those with PGVs, 177 (97.8%) were potentially eligible for increased screening per NCCN/expert opinion guidelines, 69 (38.1%) targeted therapies, and 89 (49.2%) clinical trials; this included 41 (22.7%), 6 (3.3%), and 14 (7.7%) patients, respectively, that did not meet NCCN testing criteria. 1445 variants of uncertain significance (VUS) were identified in 833 (57.7%) patients, but no difference in VUS rate was observed between those meeting and not meeting criteria (p=0.7354). Conclusions: Overall PGV rate among cancer patients from one center in Jordan was similar to that reported in the literature. While the VUS rate was high, similar rates were observed in those meeting and not meeting criteria. Testing restricted to guidelines could have missed approximately a quarter of patients with PGVs, >95% of whom might qualify for increased screening, targeted therapies, and/or clinical trials. [Table: see text]