Germline variants screening of MLH1, MSH2, MSH6 and PMS2 genes in 64 Algerian Lynch syndrome families: The first nationwide study.

Colorectal cancer is the second leading cause of cancer-related deaths in women and men in Algeria. Lynch syndrome (LS) is an autosomal dominant disease caused by heterozygous germline pathogenic variants in mismatch repair genes (MMR) and frequently predisposes to colorectal cancer. However, data about MMR germline pathogenic variants in Algerian patients are limited. This first nationwide study aims to describe clinicopathologic features and germline variants in MMR genes in Algerian families with suspected LS. Sixty-four (64) families with suspected LS were studied. Index cases with LS who fulfilled Amsterdam criteria were screened by PCR-direct sequencing for germline variants in MMR genes: MLH1 (exons 1, 9, 10, 13, 16), MSH2 (exons 5, 6, 7, 12), MSH6 (exons 4 and 8) and PMS2 (exons 6 and 10). We selected these specific risk exons genes since they have a higher probability of harboring pathogenic variants. In addition, two unrelated LS patients were screened by next-generation sequencing using a cancer panel of 30 hereditary cancer genes. Six germline pathogenic variants and one germline likely pathogenic variant were identified in 19 (29.68%) families (4 MLH1, 2 MSH2 and 1 MSH6). Of index cases and relatives who underwent genetic testing (n = 76), 30 (39.47%) had MMR pathogenic gene variants, one (0.13%) had MMR gene likely pathogenic variant and three had MMR variant of uncertain significance, respectively. Two novel germline pathogenic variants in MLH1 (2) and one germline likely pathogenic variant in MSH6 (1) never published in individuals with LS have been detected in the present study. The recurrent MLH1 germline pathogenic variant c.1546C>T has been found in nine LS families, six of them related with two large kindreds, from four North central provinces of Algeria. In addition, the common MSH2 germline pathogenic variant c.942+3A>T has been detected in five unrelated patients with a strong LS family history. The accumulative knowledge about clinicopathological and genetic characteristics of LS in Algerian patients will impact clinical management in the areas of both prevention and treatment.

Germline mutations of the adenomatous polyposis coli (APC) gene in Algerian familial adenomatous polyposis cohort: first report.

BACKGROUND: Familial adenomatous polyposis (known also as classical or severe FAP) is a rare autosomal dominant colorectal cancer predisposition syndrome, characterized by the presence of hundreds to thousands of adenomatous polyps in the colon and rectum from an early age. In the absence of prophylactic surgery, colorectal cancer (CRC) is the inevitable consequence of FAP. The vast majority of FAP is caused by germline mutations in the adenomatous polyposis coli (APC) tumor suppressor gene (5q21). To date, most of the germline mutations in classical FAP result in truncation of the APC protein and 60% are mainly located within exon 15. MATERIAL AND METHODS: In this first nationwide study, we investigated the clinical and genetic features of 52 unrelated Algerian FAP families. We screened by PCR-direct sequencing the entire exon 15 of APC gene in 50 families and two families have been analyzed by NGS using a cancer panel of 30 hereditary cancer genes. RESULTS: Among 52 FAP index cases, 36 had 100 or more than 100 polyps, 37 had strong family history of FAP, 5 developed desmoids tumors, 15 had extra colonic manifestations and 21 had colorectal cancer. We detected 13 distinct germline mutations in 17 FAP families. Interestingly, 4 novel APC germline pathogenic variants never described before have been identified in our study. CONCLUSIONS: The accumulating knowledge about the prevalence and nature of APC variants in Algerian population will contribute in the near future to the implementation of genetic testing and counseling for FAP patients.

Association of vitamin D deficiency and insulin resistance with breast cancer in premenopausal Algerian women: A cross-sectional study.

BACKGROUND: Low 25(OH)D levels are mainly related to breast cancer (BC) risk in postmenopausal women, while the impact of insulin resistance (IR) on BC prognosis is controversial. OBJECTIVE: Considering the high prevalence of BC in younger Algerian women, this cross-sectional study analyzed whether vitamin D status and IR are biomarkers for breast tumor status in premenopausal women. METHODS: In 96 women (mean age, 40.96±0.65years) newly diagnosed with BC, tumor status was determined immunohistochemically, classified by molecular subtype, then correlated with body-mass index, total plasma 25(OH)D, insulin and glucose levels and HOMA-IR, using Chi2, Student t, Spearman and ANOVA tests and multivariate logistic regression. RESULTS: A total of 66 of the 96 patients (68.75%) showed vitamin D deficiency (9.74ng/mL). Overweight and obese patients with HOMA-IR>2.5, positive for HER2 and with high Ki-67 index had the most severe vitamin D deficiency. There was a significant association between vitamin D deficiency, high Ki-67 index (OR, 14.55; 95% CI: 3.43-82.59; P=0.00078) and IR (OR, 4.99; 95% CI: 1.27-24.47; P=0.03), and between IR and HER2-positivity (OR, 3.23; 95% CI: 1.05-10.56; P=0.04). CONCLUSIONS: Vitamin D deficiency and IR are potential biomarkers for poorer prognosis in BC patients, independently of and/or synergically with high Ki-67 index and HER2-positivity in premenopausal overweight or obese women. The potential relationship of vitamin D receptor gene expression with breast cancer survival in Algerian patients will be investigated in a large cohort.

BRCA1 and BRCA2 Germline Mutation Analysis in Hereditary Breast/Ovarian Cancer Families from the Aures Region (Eastern Algeria): First Report.

Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. In this study, we aimed to investigate the mutation spectrum of BRCA1 and BRCA2 genes in hereditary breast/ovarian cancer (HBOC) families from the Aures region (eastern Algeria). High risk breast/ovarian cancer families were selected from overall 1162 consecutive patients collected from cancer registry of anticancer center of Batna. Breast cancers were diagnosed between 2011 and 2015. Recurrent mutations on BRCA1 and BRCA2 previously found in Algerian patients were screened using PCR-direct sequencing in 113 HBOC families. In addition, for the first time in Algeria, HBOC patients were analyzed by NGS using a cancer panel of 30 hereditary cancer genes or BRCA1/2 genetic test. Six distinct deleterious mutations in BRCA1 and BRCA2 and a new VUS in PALB2 were detected in ten patients. Two distinct BRCA2 pathogenic variants c.1813dupA and c.8485C > T detected in two young female triple negative breast cancer (TNBC) patients, respectively, with a family history of male breast cancer, are reported here for the first time in Algerian population. Interestingly, we also detected a BRCA exon 15 deletion in two unrelated young female TNBC patients with strong family history of breast/ovarian cancer. Our study showed differences in the distribution of the mutation spectrum of BRCA genes between the Aures region and the north central region of Algeria. Our results will contribute in the implementation of genetic counseling and testing for patients and families at risk of hereditary breast and ovarian cancer.

Correction to: BRCA1 and BRCA2 Germline Mutation Analysis in Hereditary Breast/Ovarian Cancer Families from the Aures Region (Eastern Algeria): First Report.

The original version of this article unfortunately contained an error in the abstract section and Figure 2h image.

Clinico-epidemiological profile and redox imbalance of lung cancer patients in Algeria.

Hypothesis: How are the epidemiologic repartition and the physiopathology of lung cancer (LC) in Algeria? Objective: Our study aimed to establish the clinico-epidemiological profile and evaluate redox imbalance in Algerian patients with LC. Methods and results: Our study concerned 94 Algerian patients with LC treated at two hospitals of Algiers, the capital of Algeria. The clinico-epidemiological profile was established. Moreover, the redox imbalance was evaluated by dosing oxidative stress (OS) parameters in tumor tissues and blood. We noted that the average age was 62.06 years, and 79 among the 94 patients were male, 94.59% of which were smokers. The most common histological type was adenocarcinoma (45.45% of cases), followed by squamous cell carcinoma (37.88%) small-cell carcinoma (4.86%) and other histological types (6.67%), while the most frequent clinical stage was IV (66.95 %). 23 of the 94 patients were exposed to particular risk factors such as masonry products, metal mechanics, coal smoke and so forth. In other respects, the OS parameters: NO (Nitrogen monoxide), AOPP (Advanced Oxidation Protein Products) and MDA (Malondialdehyde) were higher in tumor tissues compared to peritumoral stroma (control), unlike the catalase activity. Otherwise, AOPP and MDA were significantly higher in patients' blood than in healthy control blood, in contrast to the catalase activity. Discussion: The LC has a heterogeneous repartition regarding the sex, age, histological types, the smoking status and professional exposition to risk factors in the Algerian population. Moreover, the oxidative stress impacts the physiopathology of LC.

Clinicopathological and Molecular Study of Triple-Negative Breast Cancer in Algerian Patients.

Triple-negative breast cancer (TNBC) is associated with aggressive tumor behavior, poor prognosis and BRCA1 mutations. There are limited data regarding TNBC among Algerian women. In this study, we sought to determine clinical and tumor characteristics associated with TNBC. We also screened for the prevalence of BRCA1 mutations in unselected cohort of TNBC patients. Clinical and tumor characteristics data of 877 breast cancer patients diagnosed between 2011 and 2015, were collected from cancer registry of public hospital of Rouiba. Patients were divided in two groups: those with TNBC and those with other breast cancer subtypes. Differences between the two groups with regard to clinical and tumor characteristics were compared using Fisher's exact test. BRCA1 mutations analysis was performed in unselected cohort of 103 women with TNBC, including all exons where a mutation was previously found in Algerian population (exons 2, 3, 5, 11). The median age at diagnosis for TNBC and non-TNBC patients was 47.4 years and 49.4 years, respectively. The proportion of TNBC was 19.95%. Our data showed significant differences in menopausal status, TNM stage, histological type, tumor histological grade, Ki67 expression and family history of breast cancer between TNBC and non-TNBC patients. Four distinct deleterious mutations in BRCA1 gene were detected in eight young TNBC patients. TNBC is associated with young age, poor histopathological characteristics and family history of breast cancer. BRCA1 mutations have been detected in young TNBC patients. TNBC phenotype should be added as criterion to screen for BRCA1 mutations in Algerian women.

Distribution of molecular breast cancer subtypes among Algerian women and correlation with clinical and tumor characteristics: a population-based study.

BACKGROUND: Breast cancer is currently the leading cause of cancer morbidity and mortality among Algerian women. Molecular classification of breast cancer is an important factor for prognosis and clinical outcome. There are limited data regarding molecular breast cancer subtypes among Algerian women. The objective of the present study was to analyze the proportion and distribution of molecular subtypes and to determine their associations with some clinical and tumor characteristics: age at diagnosis, menopausal status, histological type and histological grade. MATERIALS AND METHODS: The study population included 3014 female breast cancers. We analyzed breast cancers from cancer registries of academic medical oncology service of public hospital of Rouiba, anticancer center of Blida, and anticancer center of Batna. Breast cancers were diagnosed between 2008 and 2013. Molecular subtype classification was done based on immunohistochemical surrogates for ER (Estrogen receptor), PR (Progesterone receptor) and HER2 (human epidermal growth factor receptor-2) status obtained from medical records for 3014 breast cancer patients. Breast cancer subtypes definitions were as follow: Luminal A (ER+ and/or PR+, HER2-), Luminal B (ER+ and/or PR+, HER2+), TNBC (ER-, PR - , HER2-), HER2+ (ER-, PR-, HER2+). Molecular subtypes were correlated with the clinicopathological characteristics of the tumors. RESULTS: The mean age at diagnosis cancer was 48.5 years. Proportions of the luminal A, TNBC, luminal B and HER2+ breast cancer subtypes were 50.59%, 20.80%, 19.67% and 8.92%, respectively. We noted a significant difference in the distribution of age at diagnosis among the four cancer subtypes (P= 0.004). Luminal A, Luminal B, TNBC and HER2+ subtypes were significantly different by premenopausal and postmenopausal status (P= 0.01). Invasive Ductal Carcinoma was the most common histological type in all breast cancer subtypes. Tumors with histological grade 2 and 3 were more common in patients for the four breast cancer subtypes. CONCLUSIONS: For the first time, we report the distribution of molecular breast cancer subtypes and their associations with some clinicopathological characteristics in a large cohort of Algerian women. In our current study, the median age of diagnosis for all breast cancer subtypes was younger than the average age in Europe and America. Luminal A was the most common sub- type in our patients followed by TNBC. The proportion of luminal A subtype was lesser than reported in white women with breast cancer in Europe and America. The proportion of TNBC subtype in Algerian women was higher compared with Caucasian women of European ancestry. This study will contribute in developing optimal clinical trial protocols and personalized management strategies for Algerian breast cancer patients.

BRCA1 and BRCA2 unclassified variants and missense polymorphisms in Algerian breast/ovarian cancer families.

BACKGROUND: BRCA1 and BRCA2 germline mutations predispose heterozygous carriers to hereditary breast/ovarian cancer. However, unclassified variants (UVs) (variants with unknown clinical significance) and missense polymorphisms in BRCA1 and BRCA2 genes pose a problem in genetic counseling, as their impact on risk of breast and ovarian cancer is still unclear. The objective of our study was to identify UVs and missense polymorphisms in Algerian breast/ovarian cancer patients and relatives tested previously for BRCA1 and BRCA2 genes germline mutations analysis. METHODS: We analyzed 101 DNA samples from 79 breast/ovarian cancer families. The approach used is based on BRCA1 and BRCA2 sequence variants screening by SSCP or High-Resolution Melting (HRM) curve analysis followed by direct sequencing. In silico analyses have been performed using different bioinformatics programs to individualize genetics variations that can disrupt the BRCA1 and BRCA2 genes function. RESULTS: Among 80 UVs and polymorphisms detected in BRCA1/2 genes (33 BRCA1 and 47 BRCA2), 31 were new UVs (10 BRCA1 and 21 BRCA2), 7 were rare UVs (4 BRCA1 and 3 BRCA2) and 42 were polymorphic variants (19 BRCA1 and 23 BRCA2). Moreover, 8 new missense UVs identified in this study: two BRCA1 (c.4066C>A/p.Gln1356Lys, c.4901G>T/p.Arg1634Met) located respectively in exons 11 and 16, and six BRCA2 (c.1099G>A/p.Asp367Asn, c.2636C>A/p.Ser879Tyr, c.3868T>A/p.Cys1290Ser, c.5428G>T/p.Val1810Phe, c.6346C>G/p.His2116Asp and c.9256G>A/p.Gly3086Arg) located respectively in exons 10, 11 and 24, show a damaging PSIC score yielded by PolyPhen2 program and could be pathogenic. In addition, 5 new BRCA} missense UVs out of six that were found to be damaging by PolyPhen2 program, also were deleterious according to SIFT program. The rare BRCA1 UV c.5332G>A/p.Asp1778Asn was found here for the first time in co-occurrence in trans with the deleterious BRCA1 mutation c.798_799delTT/p.Ser267LysfsX19 in young breast cancer patient. Moreover, 10 new identified intronic variants with unknown clinical significance (3 BRCA1 and 7 BRCA2) in the present study, could be considered as benign, because GeneSplicer, SpliceSiteFinder and MaxEntScan prediction programs show no splice site alteration for these variants. Several missense polymorphisms of BRCA1 c.2612C>T/p.Pro871Leu, c.3548A>G/p.Lys1183Arg, c.4837A>G/p.Ser1613Gly and BRCA2 c.865A>C/p.Asn289His, c.1114A>C/p.Asn372His, c.2971A>G/p.Asn991Asp, c.7150C>A/p.Gly2384Lys have been identified with high frequency in patients who were tested negative for BRCA1 and BRCA2 mutations. These missense polymorphisms could have a role as susceptibility breast cancer markers in Algerian breast/ovarian cancer families where pathological BRCA1 and BRCA2 mutations were not present. CONCLUSIONS: For the first time, UVs and missense polymorphisms in BRCA1 and BRCA2 genes have been identified in Algerian breast/ovarian cancer families. Evaluation of breast/ovarian cancer risk induced by the eight new missense UVs and common polymorphisms detected in our present work is on going in a larger study.

BRCA1 and BRCA2 germline mutation spectrum in hereditary breast/ovarian cancer families from Maghrebian countries.

OBJECTIVE: To summarize the knowledge about BRCA1 and BRCA2 germline mutation spectrum in Maghrebian countries. METHODS: We performed a systematic review of the literature to determine the impact of BRCA1 and BRCA2 mutations on hereditary breast/ovarian cancer in the Maghrebian population from Algeria, Morocco and Tunisia. We searched all available data published in Pubmed, Scopus, Cancerlit® databases and other scientific literatures sources. RESULTS: Pathogenic mutations in BRCA1 gene were detected by DNA sequencing in 17.43% (34/195) of analyzed breast/ovarian cancer families from Algeria, Morocco and Tunisia. One common mutation c.798_799delTT was identified in the BRCA1 gene with a frequency of 5.12%. Pathogenic BRCA2 mutations were identified in 11 out 146 families (7.53%). A new common BRCA2 pathogenic mutation c.7235_7236insG was detected in Algerian and Moroccan families. CONCLUSIONS: The Maghrebian population from Algeria, Morocco and Tunisia has just been started to be extensively studied; consequently knowledge of the prevalence and spectrum of BRCA1 and BRCA2 mutations in these populations is getting dense. The implications of these new findings in regard to genetic testing and counseling are substantial for patients and families at risk.

BRCA1 and BRCA2 germline mutations screening in Algerian breast/ovarian cancer families.

BACKGROUND: Breast cancer is the leading cause of cancer death in women in Algeria. The contribution of BRCA1 and BRCA2 mutations to hereditary breast/ovarian cancer in Algerian population is largely unknown. Here, we describe analysis of BRCA1 and BRCA2 genes in 86 individuals from 70 families from an Algerian cohort with a personal and family history suggestive of genetic predisposition to breast cancer. METHODS: The approach used is based on BRCA1 and BRCA2 mutations screening by High-Resolution Melting (HRM) curve analysis followed by direct sequencing. All samples for which no pathogenic mutation was found were analyzed by MLPA for large deletions or duplications. RESULTS: Three distinct pathogenic mutations c.83_84delTG, c.181T>G, c.798_799delTT and two large rearrangements involving deletion of exon 2 and exon 8 respectively, were detected in BRCA1 gene. Moreover 17 unclassified variants and polymorphisms were detected in BRCA1 gene (6 described for the first time). Two pathogenic mutations, c.1310_1313delAAGA and c.5722_5723delCT and 40 unclassified variants and polymorphisms (14 never described before) were identified in BRCA2 gene. CONCLUSIONS: For the first time, we used HRM and MLPA to identify BRCA1 and BRCA2 mutations in Algerian patients with a personal and family history suggestive of genetic predisposition to breast cancer. The implications of these new findings in regard to genetic testing and counseling are substantial for the Algerian population.