Disclosure of familial implications of pathogenic variants in breast-cancer genes to patients: Opportunity for prompting family communication

Background: Mutations in hereditary breast cancer genes play an important role in the risk for cancer, however, little is known of the type and frequency of mutations in Central American populations, including Guatemala. Methods: Two separate panels of known cancer susceptibility genes were used to sequence blood DNA from 664 unselected breast cancer cases from two large hospitals in Guatemala. Variants were annotated with ClinVar and VarSome. Data from a structured questionnaire was used to compare mutation carriers of medium and high penetrance genes. Results: A total of 73 out of 664 subjects (11%) had a variant classified as pathogenic in a gene with known high or medium penetrance for inherited breast cancer. The most frequently mutated genes were BRCA1 (37/664, 5.6%) followed by BRCA2 (15/664, 2.3%), PALB2 (5/664, 0.8%) and TP53 (5/664, 0.8%). Pathogenic variants were also detected in the moderate penetrance genes ATM, BARD1, CHEK2, and MSH6, and rare pathogenic variants detected in the low penetrance genes AXIN2, FH, MLH1, MSH2, MUTYH, NF1, and SDHB. The high ratio of BRCA1/BRCA2 mutations is due to the presence of two potential founder mutations, BRCA1 c.212+1G>A splice mutation (15 cases) and BRCA1 c.799delT (9 cases). Compared to all others, cases with pathogenic mutations had a significantly earlier age at diagnosis (45 vs 51 years, P<0.001), more likely to have had diagnosis before menopause, and a higher percentage had a relative with any cancer (51% vs 37%, P=0.038) or breast cancer (33% vs 15%, P<0.001). Mammography usage was less frequent in lower SES women indicating this group is less likely to be screened for breast cancer (p < 0.001). Conclusions: Guatemalan women have rates of hereditary breast cancer mutations similar to other populations, and these women are more likely to have early age at diagnosis and family history. This data supports the use of genetic testing in breast cancer patients and those at high risk as part of a strategy to reduce breast cancer mortality in Guatemala.

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Germline mutations in hereditary breast cancer genes are associated with early age at diagnosis and family history in Guatemalan breast cancer

10.21203/rs.3.rs-58163/v1 ◽

2020 ◽

Author(s):

Megan Ren ◽

Anali Orozco ◽

Kang Shao ◽

Anaseidy Albanez ◽

Jeremy Ortiz ◽

...

Keyword(s):

Breast Cancer ◽

Family History ◽

Hereditary Breast Cancer ◽

Breast Cancer Mortality ◽

Age At Diagnosis ◽

Early Age ◽

Cancer Genes ◽

Pathogenic Variants ◽

Cancer Susceptibility Genes ◽

Breast Cancer Genes

Abstract Background: Mutations in hereditary breast cancer genes play an important role in the risk for cancer, however, little is known of the type and frequency of mutations in Central American populations, including Guatemala.Methods: Two separate panels of known cancer susceptibility genes were used to sequence blood DNA from 664 unselected breast cancer cases from two large hospitals in Guatemala. Variants were annotated with ClinVar and VarSome. Data from a structured questionnaire was used to compare mutation carriers of medium and high penetrance genes.Results: A total of 73 out of 664 subjects (11%) had a variant classified as pathogenic in a gene with known high or medium penetrance for inherited breast cancer. The most frequently mutated genes were BRCA1 (37/664, 5.6%) followed by BRCA2 (15/664, 2.3%), PALB2 (5/664, 0.8%) and TP53 (5/664, 0.8%). Pathogenic variants were also detected in the moderate penetrance genes ATM, BARD1, CHEK2, and MSH6, and rare pathogenic variants detected in the low penetrance genes AXIN2, FH, MLH1, MSH2, MUTYH, NF1, and SDHB. The high ratio of BRCA1/BRCA2 mutations is due to the presence of two potential founder mutations, BRCA1 c.212 + 1G > A splice mutation (15 cases) and BRCA1 c.799delT (9 cases). Compared to all others, cases with pathogenic mutations had a significantly earlier age at diagnosis (45 vs 51 years, P < 0.001), more likely to have had diagnosis before menopause, and a higher percentage had a relative with any cancer (51% vs 37%, P = 0.038) or breast cancer (33% vs 15%, P < 0.001). Mammography usage was less frequent in lower SES women indicating this group is less likely to be screened for breast cancer (p < 0.001).Conclusions: Guatemalan women have rates of hereditary breast cancer mutations similar to other populations, and these women are more likely to have early age at diagnosis and family history. This data supports the use of genetic testing in breast cancer patients and those at high risk as part of a strategy to reduce breast cancer mortality in Guatemala.

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Germline pathogenic variants of 11 breast cancer genes in 7,051 Japanese patients and 11,241 controls

Nature Communications ◽

10.1038/s41467-018-06581-8 ◽

2018 ◽

Vol 9 (1) ◽

Cited By ~ 38

Author(s):

Yukihide Momozawa ◽

Yusuke Iwasaki ◽

Michael T. Parsons ◽

Yoichiro Kamatani ◽

Atsushi Takahashi ◽

...

Keyword(s):

Breast Cancer ◽

Japanese Patients ◽

Cancer Genes ◽

Pathogenic Variants ◽

Breast Cancer Genes

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Statistical Genetic Methods for Localizing Multiple Breast Cancer Genes.

10.21236/ada301699 ◽

1995 ◽

Author(s):

Jurg Ott

Keyword(s):

Breast Cancer ◽

Cancer Genes ◽

Breast Cancer Genes

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Statistical Genetics Methods for Localizing Multiple Breast Cancer Genes.

10.21236/ada337861 ◽

1997 ◽

Author(s):

Jurg Ott

Keyword(s):

Breast Cancer ◽

Statistical Genetics ◽

Cancer Genes ◽

Breast Cancer Genes

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High likelihood of actionable pathogenic variant detection in breast cancer genes in women with very early onset breast cancer

Journal of Medical Genetics ◽

10.1136/jmedgenet-2020-107347 ◽

2021 ◽

pp. jmedgenet-2020-107347

Author(s):

D Gareth Evans ◽

Elke Maria van Veen ◽

Helen J Byers ◽

Sarah J Evans ◽

George J Burghel ◽

...

Keyword(s):

Breast Cancer ◽

Early Onset ◽

Ductal Carcinoma ◽

Cancer Genes ◽

Early Onset Breast Cancer ◽

Younger Women ◽

Pathogenic Variants ◽

Younger Age ◽

Predisposition Genes

BackgroundWhile the likelihood of identifying constitutional breast cancer-associated BRCA1, BRCA2 and TP53 pathogenic variants (PVs) increases with earlier diagnosis age, little is known about the correlation with age at diagnosis in other predisposition genes. Here, we assessed the contribution of known breast cancer-associated genes to very early onset disease.MethodsSequencing of BRCA1, BRCA2, TP53 and CHEK2 c.1100delC was undertaken in women with breast cancer diagnosed ≤30 years. Those testing negative were screened for PVs in a minimum of eight additional breast cancer-associated genes. Rates of PVs were compared with cases ≤30 years from the Prospective study of Outcomes in Sporadic vs Hereditary breast cancer (POSH) study.ResultsTesting 379 women with breast cancer aged ≤30 years identified 75 PVs (19.7%) in BRCA1, 35 (9.2%) in BRCA2, 22 (5.8%) in TP53 and 2 (0.5%) CHEK2 c.1100delC. Extended screening of 184 PV negative women only identified eight additional actionable PVs. BRCA1/2 PVs were more common in women aged 26–30 years than in younger women (p=0.0083) although the younger age group had rates more similar to those in the POSH cohort. Out of 26 women with ductal carcinoma in situ (DCIS) alone, most were high-grade and 11/26 (42.3%) had a PV (TP53=6, BRCA2=2, BRCA1=2, PALB2=1). This PV yield is similar to the 61 (48.8%) BRCA1/2 PVs identified in 125 women with triple-negative breast cancer. The POSH cohort specifically excluded pure DCIS which may explain lower TP53 PV rates in this group (1.7%).ConclusionThe rates of BRCA1, BRCA2 and TP53 PVs are high in very early onset breast cancer, with limited benefit from testing of additional breast cancer-associated genes.

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