[Show abstract][Hide abstract] ABSTRACT: We identified an MSH6 mutation (c.10C>T, p.Gln4*) causing Lynch syndrome (LS) in 11 French Canadian (FC) families from the Canadian province of Quebec. We aimed to investigate the molecular and clinical implications of this mutation among FC carriers and to assess its putative founder origin. We studied 11 probands and 27 family members. Additionally 6,433 newborns, 187 colorectal cancer (CRC) cases, 381 endometrial cancer (EC) cases and 179 additional controls, all of them from Quebec, were used. Found in ~1/400 newborns, the mutation is one of the most common LS mutations described. We have found that this mutation confers a greater risk for EC than for CRC, both in the 11 studied families and in the unselected cases: EC (OR=7.5, p < 0.0001) and CRC (OR=2.2, p = 0.46). Haplotype analyses showed that the mutation arose in a common ancestor, probably around 430–656 years ago, coinciding with the arrival of the first French settlers. Application of the results of this study could significantly improve the molecular testing and clinical management of LS families in Quebec.
[Show abstract][Hide abstract] ABSTRACT: IntroductionThe infiltration of FOXP3+ regulatory T-cells into invasive tumors has been reported to be associated with survival in a variety of cancers. The prognostic significance of FOXP3+ tumor infiltrating lymphocytes (TILs) in breast cancer, however, remains controversial.MethodsFOXP3+ TILs were assessed by immunohistochemistry on tissue microarrays constructed from a well-defined cohort of 3,992 breast cancer patients linked to detailed demographic, biomarker, treatment and outcome data. Survival analyses were performed using the Kaplan-Meier function and Cox proportional hazards regression models to evaluate the association of FOXP3+ TILs with breast cancer specific survival, stratified by intrinsic subtype and cytotoxic T-cell infiltration status (as defined by CD8 immunohistochemistry).ResultsThe presence of high numbers of FOXP3+ TILs was significantly associated with young age, high grade, estrogen receptor (ER) negativity, concurrent CD8+ cytotoxic T-cell infiltration, and human epidermal growth factor receptor-2 positive (HER2+)/ER¿ and core basal subtypes. On multivariate survival analysis, a high level of FOXP3+ TILs was significantly associated with poor survival in ER+ breast cancers that lacked CD8+ T-cell infiltrates (Hazard ratio (HR)¿=¿1.30, 95% confidence interval (CI)¿=¿1.02 to 1.66). However, in ER¿ breast cancers, FOXP3+ TILs were strongly associated with improved survival in the HER2+/ER¿ subgroup, particularly in those with co-existent CD8+ T-cell infiltrates (HR¿=¿0.48, 95% CI¿=¿0.23 to 0.98), for which the presence of high levels of FOXP3+ TILs was independent of standard clinical prognostic factors.ConclusionsFOXP3+ regulatory TILs are a poor prognostic indicator in ER+ breast cancer, but a favorable prognostic factor in the HER2+/ER¿ subtype. The prognostic value of FOXP3+ TILs in breast cancer differs depending on ER and HER2 expression status and CD8+ T-cell infiltration.
Breast cancer research: BCR 09/2014; 16(5):432. · 5.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Dicer is central to microRNA-mediated silencing and several other RNA interference phenomena that are profoundly embedded in cancer gene networks. Most recently, both germline and somatic mutations in DICER1 have been identified in diverse types of cancer. Although some of the mutations clearly reduce the dosage of this key enzyme, others dictate surprisingly specific changes in select classes of small RNAs. This Review reflects on the molecular properties of the Dicer enzymes in small RNA silencing pathways, and rationalizes the newly discovered mutations on the basis of the activities and functions of its determinants.
[Show abstract][Hide abstract] ABSTRACT: Women with a genetic predisposition to breast cancer may be at increased risk of cancer after exposure to ionizing radiation. It is unclear whether mammography screening increases the risk of breast cancer among BRCA1 and BRCA2 carriers. We identified 2,346 women with a BRCA1 (n = 1844) or BRCA2 (n = 502) mutation and no breast cancer, and we reviewed their history of mammography exposure. These women were followed for an average of 5.3 years and were observed for new breast cancer diagnoses. At study entry, 1808 women (77.1 %) reported ever having had a mammogram; of these, 204 women (11.2 %) reported having had a mammogram before age 30. We estimated the hazard ratios for the development of invasive breast cancer, conditional on the number of prior mammograms and on the age at first mammogram. Hazard ratios were estimated and stratified by gene (BRCA1 or BRCA2), relative to women with no exposure. We observed no significant association between prior mammography exposure and breast cancer risk for BRCA1 carriers (HR 0.79; 95 % CI 0.53-1.19; P = 0.26) or for BRCA2 carriers (HR 0.90; 95 % CI 0.35-2.34; P = 0.83). An early age at first mammogram (<30 years) did not increase breast cancer risk among BRCA1 carriers (HR 0.75; 95 % CI 0.41-1.37; P = 0.35) or among BRCA2 carriers (HR 0.69; 95 % CI 0.19-2.48; P = 0.57). Exposure to mammography in women with BRCA1 and BRCA2 mutations is not associated with an increased risk of breast cancer.
Breast Cancer Research and Treatment 08/2014; · 4.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Germ-line RB-1 mutations predispose to pineoblastoma (PinB), but other predisposing genetic factors are not well established. We recently identified a germ-line DICER1 mutation in a child with a PinB. This was accompanied by loss of heterozygosity (LOH) of the wild-type allele within the tumour. We set out to establish the prevalence of DICER1 mutations in an opportunistically ascertained series of PinBs. Twenty-one PinB cases were studied: Eighteen cases had not undergone previous testing for DICER1 mutations; three patients were known carriers of germ-line DICER1 mutations. The eighteen PinBs were sequenced by Sanger and/or Fluidigm-based next-generation sequencing to identify DICER1 mutations in blood gDNA and/or tumour gDNA. Testing for somatic DICER1 mutations was also conducted on one case with a known germ-line DICER1 mutation. From the eighteen PinBs, we identified four deleterious DICER1 mutations, three of which were germ line in origin, and one for which a germ line versus somatic origin could not be determined; in all four, the second allele was also inactivated leading to complete loss of DICER1 protein. No somatic DICER1 RNase IIIb mutations were identified. One PinB arising in a germ-line DICER1 mutation carrier was found to have LOH. This study suggests that germ-line DICER1 mutations make a clinically significant contribution to PinB, establishing DICER1 as an important susceptibility gene for PinB and demonstrates PinB to be a manifestation of a germ-line DICER1 mutation. The means by which the second allele is inactivated may differ from other DICER1-related tumours.
[Show abstract][Hide abstract] ABSTRACT: Women with Lynch syndrome (LS) are at increased risk for the development of epithelial ovarian cancer (OC). Analogous to previous studies on BRCA1/2 mutation carriers, there is evidence to suggest a histotype-specific association in LS-associated OCs (LS-OC). Whereas the diagnosis of high-grade serous carcinoma is an indication for BRCA1/2 germline testing, in contrast, there are no screening guidelines in place for triaging OC patients for LS testing based on histotype. We performed a centralized pathology review of tumor subtype on 20 germline mutation-confirmed LS-OCs, on the basis of morphologic assessment of hematoxylin and eosin-stained slides, with confirmation by immunohistochemistry when necessary. Results from mismatch-repair immunohistochemistry (MMR-IHC) and microsatellite instability (MSI) phenotype status were documented, and detailed pedigrees were analyzed to determine whether previously proposed clinical criteria would have selected these patients for genetic testing. Review of pathology revealed all LS-OCs to be either pure endometrioid carcinoma (14 cases), mixed carcinoma with an endometrioid component (4 cases), or clear cell carcinoma (2 cases). No high-grade or low-grade serous carcinomas or mucinous carcinomas of intestinal type were identified. Tumor-infiltrating lymphocytes were prominent (≥40 per 10 high-powered fields) in 2 cases only. With the exception of 1 case, all tumors tested for MMR-IHC or MSI had an MMR-deficient phenotype. Within this cohort, 50%, 55%, 65%, and 85% of patients would have been selected for genetic workup by Amsterdam II, revised Bethesda Guidelines, SGO 10% to 25%, and SGO 5% to 10% criteria, respectively, with <60% of index or sentinel cases detected by any of these schemas. To further support a subtype-driven screening strategy, MMR-IHC reflex testing was performed on all consecutive non-serous OCs diagnosed at 1 academic hospital over a 2-year period; MMR deficiency was identified in 10/48 (21%) cases, all with endometrioid or clear cell histology. We conclude that there is a strong association between endometrioid and clear cell ovarian carcinomas and hereditary predisposition due to MMR gene mutation. These findings have implications for the role of tumor subtype in screening patients with OC for further genetic testing and support reflex MMR-IHC and/or MSI testing for newly diagnosed cases of endometrioid or clear cell ovarian carcinoma.
The American journal of surgical pathology. 07/2014;
[Show abstract][Hide abstract] ABSTRACT: Women with a mutation in BRCA1 or BRCA2 face a lifetime risk of breast cancer of approximately 80 %. Tamoxifen treatment of the first cancer has been associated with a reduction in the risk of a subsequent contralateral cancer. We studied 1,504 women with a known BRCA1 or BRCA2 mutation, 411 women with bilateral breast cancer (cases) and 1,093 women with unilateral breast cancer (controls) in a matched case-control study. Control women were of similar age and had a similar age of diagnosis of first breast cancer as the cases. For each woman who used tamoxifen, the starting and stopping dates were abstracted and the duration of tamoxifen use was calculated. Three hundred and thirty-one women had used tamoxifen (22 %); of these 84 (25 %) had completed four or more years of tamoxifen, the remainder stopped prematurely or were current users. For women with up to 1 year of tamoxifen use, the odds ratio for contralateral breast cancer was 0.37 (95 % CI 0.20-0.69; p = 0.001) compared to women with no tamoxifen use. Among women with 1-4 years of tamoxifen use the odds ratio was 0.53 (95 % CI 0.32-0.87; p = 0.01). Among women with four or more years of tamoxifen use the odds ratio was 0.83 (95 % CI 0.44-1.55; p = 0.55). Short-term use of tamoxifen for chemoprevention in BRCA1 and BRCA2 mutation carriers may be as effective as a conventional 5-year course of treatment.
Breast Cancer Research and Treatment 06/2014; · 4.47 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We demonstrate autosomal-recessive CARD9 deficiency in a patient with relapsing Candida albicans meningoencephalitis. The novel, hypomorphic mutation impaired GM-CSF but not Th17 responses. Adjunctive GM-CSF therapy resulted in clinical remission, suggesting that a CARD9/GM-CSF axis contributes to susceptibility to candidiasis.
[Show abstract][Hide abstract] ABSTRACT: The risk of breast cancer in carriers of BRCA1 and BRCA2 mutations is influenced by factors other than the genetic mutation itself. Modifying factors include a woman's reproductive history and family history of cancer. Risk factors are more likely to be present in women with breast cancer than in women without breast cancer, and therefore the risk of cancer in the two breasts should not be independent. It is not clear to what extent modifying factors influence the risk of a first primary or a contralateral breast cancer in BRCA carriers.
We conducted a matched case-control study of breast cancer among 3920 BRCA1 or BRCA2 mutation carriers. We asked whether a past history of breast cancer in the contralateral breast was a risk factor for breast cancer.
After adjustment for age, country of residence, and cancer treatment, a previous cancer of the right breast was found to be a significant risk factor for cancer of the left breast among BRCA1 or BRCA2 carriers (relative risk: 2.1; 95% confidence interval: 1.4 to 3.0; p < 0.0001).
In a woman with a BRCA1 or BRCA2 mutation who is diagnosed with breast cancer, the risk of cancer in the contralateral breast depends on the first diagnosis. That observation supports the hypothesis that there are important genetic or non-genetic modifiers of cancer risk in BRCA carriers. Discovering risk modifiers might lead to greater personalization of risk assessment and management recommendations for BRCA-positive patients.
Current Oncology 04/2014; 21(2):64-8. · 1.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We explored the experiences of Ashkenazi Jewish and French Canadian women and meanings attributed to their hereditary breast and ovarian cancer (HBOC) risk. We purposively sampled 40 BRCA1 or BRCA2 (BRCA) mutation carriers and conducted theoretically driven semistructured interviews. According to content analysis, participants from these two ethnocultural groups held divergent meanings associated with being a BRCA carrier and different views pertaining to the illness experience and risk awareness. All participants identified a genetic basis; however, the French Canadian women also expressed other causes. The French Canadian women reported not knowing other carriers in their social environment, whereas the Ashkenazi Jewish women emphasized a strong sense of community contributing to their ethnic risk awareness. Based on these findings, we suggest that French Canadian women could benefit from greater awareness of the HBOC genetic risk and that health care providers should consider ethnically related and individual-based experiences and meanings during counseling.
Qualitative Health Research 04/2014; · 2.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Small cell carcinoma of the ovary, hypercalcemic type (SCCOHT) is the most common undifferentiated ovarian malignancy in women under 40 years of age. We sequenced the exomes of six individuals from three families with SCCOHT. After discovering segregating deleterious germline mutations in SMARCA4 in all three families, we tested DNA from a fourth affected family, which also carried a segregating SMARCA4 germline mutation. All the familial tumors sequenced harbored either a somatic mutation or loss of the wild-type allele. Immunohistochemical analysis of these cases and additional familial and non-familial cases showed loss of SMARCA4 (BRG1) protein in 38 of 40 tumors overall. Sequencing of cases with available DNA identified at least one germline or somatic deleterious SMARCA4 mutation in 30 of 32 cases. Additionally, the SCCOHT cell line BIN-67 had biallelic deleterious mutations in SMARCA4. Our findings identify alterations in SMARCA4 as the major cause of SCCOHT, which could lead to improvements in genetic counseling and new treatment approaches.
[Show abstract][Hide abstract] ABSTRACT: Carriers of germ-line DICER1 mutations are predisposed to a rare cancer syndrome, the DICER1 Syndrome. Thyroid abnormalities are a common finding in DICER1 syndrome with multinodular goitre (MNG) frequently present in many families in which a germ-line DICER1 mutation is segregating. Differentiated thyroid carcinoma (DTC) is infrequently seen in such pedigrees. In addition to germ-line DICER1 mutations, specific somatic mutations have been identified in the DICER1 RNase IIIb catalytic domain in several tumour types.
We aimed to determine whether such characteristic somatic DICER1 mutations are present in DTCs that arise within germ-line-DICER1 mutation carriers.
The study involved an opportunistic collection of three cases of DTC arising in individuals suspected to have DICER1 syndrome.
Hospital-based ascertainment and testing.
We identified somatic DICER1 mutations in three DTCs arising in unrelated germ-line DICER1 mutation carriers, all of whom had been diagnosed in infancy with pleuropulmonary blastoma (PPB), were treated with chemotherapy, exposed frequently to diagnostic radiation and subsequently developed DTC. The somatic mutations occurred within the DICER1 RNase IIIb domain, affecting highly conserved amino acid residues central to the catalytic activity of the domain.
This report of somatic DICER1 mutations in DTC strengthens the association between DTC and the DICER1 syndrome. The possible association between germ-line DICER1 mutations, PPB treatment and the risk of subsequent DTC must be considered by clinicians when treating PPB. Exploring the association between DICER1 mutations and differentiated thyroid carcinoma.
The Journal of Clinical Endocrinology and Metabolism 03/2014; · 6.31 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous GWAS studies have reported significant associations between various common SNPs and prostate cancer risk using cases unselected for family history. How these variants influence risk in familial prostate cancer is not well studied. Here, we analyzed 25 previously reported SNPs across 14 loci from prior prostate cancer GWAS. The International Consortium for Prostate Cancer Genetics (ICPCG) previously validated some of these using a family-based association method (FBAT). However, this approach suffered reduced power due to the conditional statistics implemented in FBAT. Here, we use a case–control design with an empirical analysis strategy to analyze the ICPCG resource for association between these 25 SNPs and familial prostate cancer risk. Fourteen sites contributed 12,506 samples (9,560 prostate cancer cases, 3,368 with aggressive disease, and 2,946 controls from 2,283 pedigrees). We performed association analysis with Genie software which accounts for relationships. We analyzed all familial prostate cancer cases and the subset of aggressive cases. For the familial prostate cancer phenotype, 20 of the 25 SNPs were at least nominally associated with prostate cancer and 16 remained significant after multiple testing correction (p ≤ 1E
−3) occurring on chromosomal bands 6q25, 7p15, 8q24, 10q11, 11q13, 17q12, 17q24, and Xp11. For aggressive disease, 16 of the SNPs had at least nominal evidence and 8 were statistically significant including 2p15. The results indicate that the majority of common, low-risk alleles identified in GWAS studies for all prostate cancer also contribute risk for familial prostate cancer, and that some may contribute risk to aggressive disease.
[Show abstract][Hide abstract] ABSTRACT: Previous GWAS studies have reported significant associations between various common SNPs and prostate cancer risk using cases unselected for family history. How these variants influence risk in familial prostate cancer is not well studied. Here, we analyzed 25 previously reported SNPs across 14 loci from prior prostate cancer GWAS. The International Consortium for Prostate Cancer Genetics (ICPCG) previously validated some of these using a family-based association method (FBAT). However, this approach suffered reduced power due to the conditional statistics implemented in FBAT. Here, we use a case-control design with an empirical analysis strategy to analyze the ICPCG resource for association between these 25 SNPs and familial prostate cancer risk. Fourteen sites contributed 12,506 samples (9,560 prostate cancer cases, 3,368 with aggressive disease, and 2,946 controls from 2,283 pedigrees). We performed association analysis with Genie software which accounts for relationships. We analyzed all familial p
[Show abstract][Hide abstract] ABSTRACT: Whole exome sequencing (WES) is revolutionizing medical diagnostics and taxonomy. In less than five years since its first use, WES has revealed unexpected molecular drivers of numerous cancers. Here, we describe our use of WES to uncover the true nature of an enigmatic pathological entity, small-cell carcinoma of the ovary, hypercalcaemic type (SCCOHT), that has resisted definitive characterization since it was first described in 1979. We conducted WES using three families with SCCOHT and identified deleterious mutations in the chromatin-remodelling gene SMARCA4 (encoding BRG1) in all cases. Follow-up of these findings, using both Sanger sequencing and WES of formalin-fixed paraffin-embedded tumours, showed that virtually all SCCOHT we studied lack functional SMARCA4/BRG1. Notably, this gene, and the related SMARCB1 gene, is mutated in most if not all atypical teratoid/rhabdoid tumours and malignant rhabdoid tumours. Other groups have similar findings. We review the relationship between these three neoplasms, discuss how they were distinguished from morphologically similar neoplasms, consider their similarities and show how WES has revealed that SCCOHTs are in fact rhabdoid tumours. We propose that SCCOHT be renamed “malignant rhabdoid tumour of the ovary” (MRTO) to reflect these observations.
The Journal of Pathology 03/2014; · 7.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purposes of this study were to estimate the reduction in risk of ovarian, fallopian tube, or peritoneal cancer in women with a BRCA1 or BRCA2 mutation after oophorectomy, by age of oophorectomy; to estimate the impact of prophylactic oophorectomy on all-cause mortality; and to estimate 5-year survival associated with clinically detected ovarian, occult, and peritoneal cancers diagnosed in the cohort.
Women with a BRCA1 or BRCA2 mutation were identified from an international registry; 5,783 women completed a baseline questionnaire and ≥ one follow-up questionnaires. Women were observed until either diagnosis of ovarian, fallopian tube, or peritoneal cancer, death, or date of most recent follow-up. Hazard ratios (HRs) for cancer incidence and all-cause mortality associated with oophorectomy were evaluated using time-dependent survival analyses.
After an average follow-up period of 5.6 years, 186 women developed either ovarian (n = 132), fallopian (n = 22), or peritoneal (n = 32) cancer, of whom 68 have died. HR for ovarian, fallopian, or peritoneal cancer associated with bilateral oophorectomy was 0.20 (95% CI, 0.13 to 0.30; P < .001). Among women who had no history of cancer at baseline, HR for all-cause mortality to age 70 years associated with an oophorectomy was 0.23 (95% CI, 0.13 to 0.39; P < .001).
Preventive oophorectomy was associated with an 80% reduction in the risk of ovarian, fallopian tube, or peritoneal cancer in BRCA1 or BRCA2 carriers and a 77% reduction in all-cause mortality.
Journal of Clinical Oncology 02/2014; · 18.04 Impact Factor