The Manchester Scoring System for predicting BRCA1/2 mutations underperforms in Arabic Omani breast cancer patients

Risk assessment models that are applied to assess the lifetime risk of cancer and pathogenic variant risk are more commonly used in Western populations. Using these models, without validation, for non-Western populations has been questioned. This study aimed to evaluate the use and consistency of the Manchester Scoring System as a risk assessment model for the Omani population. A retrospective, file-based analysis was performed on breast cancer patients seen in a genomics department over a two-year period. Personal cancer history and family history were used to analyze the Manchester scores of 409 breast and/or cancer patients. The results show that, overall, the Manchester scores were low. If this risk assessment model had been used to determine eligibility for a priori service and genetic testing decisions, 12 BRCA pathogenic cases would have been missed. At this time, the Manchester Scoring System does not seem to be the best risk assessment model for use in the Omani population, unless the eligibility threshold of ≥6 is used, which could provide a better sensitivity for the Omani population. We propose using concepts of the Manchester Scoring model to create a scoring system that is more suitable for the Omani and Arabic population.

A comprehensive reference for BRCA1/2 genes pathogenic variants in Iran: published, unpublished and novel

BRCA1 and BRCA2 are two prominent genes that account for about 20-40% of inherited breast cancer. Mutations in these genes are often associated with clustering of especially early-onset cancers in the family. The spectrum of BRCA variants showed a significant difference between geographic regions and ethnicities. The frequency and spectrum of BRCA mutations in Iran, a country in southwest Asia, have not yet been thoroughly studied. Here, for the first time, all published and not published BRCA pathogenic variants are presented. Among 1040 high risk families (1258 cases) which were detected, 116 families were found to carry pathogenic variants in either BRCA1 or BRCA2. Altogether 89 distinct types of pathogenic variants have been detected in Iran, including 41 in BRCA1 and 48 in BRCA2. 16 out of 89 mutations had not been previously reported in Iran and are presented for the first time in this article, among which 4 mutations are novel worldwide. 20% of families had one of the seven most commonly observed mutations, including c.81-1G > C, c.66_67delAG, c.4609C>T, c.1568delT, c.1961delA, in BRCA1 and: c.3751_3752insA, c.8585dupT in BRCA2. Combining the data from published articles and our study which has not been published before, a comprehensive table is created as a reference for entire BRCA pathogenic variants and their frequencies in Iran.

The NCCN Criterion "Young Age at Onset" Alone is Not an Indicator of Hereditary Breast Cancer in Iranian Population

Because the contribution of genetic factors to the burden of breast cancer is not well investigated in Iran, we aimed to examine the prevalence of mutations in breast cancer susceptibility genes, BRCA1/2 and PALB2, and to investigate the predictive potential of hereditary breast cancer risk criteria for genetic testing in Iranian population. Next-generation sequencing was conducted on a population consisting of 299 and 125 patients with breast cancer, with and without hereditary cancer risk criteria for genetic testing, respectively. The pathogenic mutation frequency rate was 10.7% in patients with hereditary cancer criteria versus 1.6% in no criteria group (P = 0.0017). None of the 107 tested patients with only young age at onset (<40) criterion had a pathogenic mutation. Patients who had only a single heritable risk criterion [OR, 6.15; 95% confidence interval (CI), 1.26-58.59; P = 0.009] and patients with multiple heritable risk criteria (OR, 22.5; 95% CI, 5.19-201.31; P < 0.0001) had higher probabilities of carrying a mutation compared with no criteria group. Our results showed that young age at onset alone is not an indicator of hereditary breast cancer at least in the Iranian population. This is while women with multiple hereditary breast cancer risk criteria were enriched for BRCA1/2 mutations. Given such high risk of identification of a disease-causing mutation, multiple hereditary criteria should be regarded as a strong predictor for a hereditary breast cancer syndrome. These findings are important concerning the optimization of genetic counseling and furthermore establishing criteria for BRCA1/2 testing of the Iranian population.