Paul Bessette

Evaluation of BRCA1 and BRCA2 mutation prevalence, risk prediction models and a multistep testing approach in French-Canadian families with high risk of breast and ovarian cancer

Background and objective: In clinical settings with fixed resources allocated to predictive genetic testing for high-risk cancer predisposition genes, optimal strategies for mutation screening programmes are critically important. These depend on the mutation spectrum found in the population under consideration and the frequency of mutations detected as a function of the personal and family history of cancer, which are both affected by the presence of founder mutations and demographic characteristics of the underlying population. The results of multistep genetic testing for mutations in BRCA1 or BRCA2 in a large series of families with breast cancer in the French-Canadian population of Quebec, Canada are reported. Methods: A total of 256 high-risk families were ascertained from regional familial cancer clinics throughout the province of Quebec. Initially, families were tested for a panel of specific mutations known to occur in this population. Families in which no mutation was identified were then comprehensively tested. Three algorithms to predict the presence of mutations were evaluated, including the prevalence tables provided by Myriad Genetics Laboratories, the Manchester Scoring System and a logistic regression approach based on the data from this study. Results: 8 of the 15 distinct mutations found in 62 BRCA1/BRCA2-positive families had never been previously reported in this population, whereas 82% carried 1 of the 4 mutations currently observed in ⩾2 families. In the subset of 191 families in which at least 1 affected individual was tested, 29% carried a mutation. Of these 27 BRCA1-positive and 29 BRCA2-positive families, 48 (86%) were found to harbour a mutation detected by the initial test. Among the remaining 143 inconclusive families, all 8 families found to have a mutation after complete sequencing had Manchester Scores ⩾18. The logistic regression and Manchester Scores provided equal predictive power, and both were significantly better than the Myriad Genetics Laboratories prevalence tables (p<0.001). A threshold of Manchester Score ⩾18 provided an overall sensitivity of 86% and a specificity of 82%, with a positive predictive value of 66% in this population. Conclusion: In this population, a testing strategy with an initial test using a panel of reported recurrent mutations, followed by full sequencing in families with Manchester Scores ⩾18, represents an efficient test in terms of overall cost and sensitivity.

Mutation analysis and characterization of ATR sequence variants in breast cancer cases from high-risk French Canadian breast/ovarian cancer families

BackgroundAtaxia telangiectasia-mutated and Rad3-related (ATR) is a member of the PIK-related family which plays, along with ATM, a central role in cell-cycle regulation. ATR has been shown to phosphorylate several tumor suppressors like BRCA1, CHEK1 and TP53. ATR appears as a good candidate breast cancer susceptibility gene and the current study was designed to screen for ATR germline mutations potentially involved in breast cancer predisposition.MethodsATR direct sequencing was performed using a fluorescent method while widely available programs were used for linkage disequilibrium (LD), haplotype analyses, and tagging SNP (tSNP) identification. Expression analyses were carried out using real-time PCR.ResultsThe complete sequence of all exons and flanking intronic sequences were analyzed in DNA samples from 54 individuals affected with breast cancer from non-BRCA1/2 high-risk French Canadian breast/ovarian families. Although no germline mutation has been identified in the coding region, we identified 41 sequence variants, including 16 coding variants, 3 of which are not reported in public databases. SNP haplotypes were established and tSNPs were identified in 73 healthy unrelated French Canadians, providing a valuable tool for further association studies involving the ATR gene, using large cohorts. Our analyses led to the identification of two novel alternative splice transcripts. In contrast to the transcript generated by an alternative splicing site in the intron 41, the one resulting from a deletion of 121 nucleotides in exon 33 is widely expressed, at significant but relatively low levels, in both normal and tumoral cells including normal breast and ovarian tissue.ConclusionAlthough no deleterious mutations were identified in the ATR gene, the current study provides an haplotype analysis of the ATR gene polymorphisms, which allowed the identification of a set of SNPs that could be used as tSNPs for large-scale association studies. In addition, our study led to the characterization of a novel Δ33 splice form, which could generate a putative truncated protein lacking several functional domains. Additional studies in large cohorts and other populations will be needed to further evaluate if common and/or rare ATR sequence variants can be associated with a modest or intermediate breast cancer risk.

Toxicity and quality of life after adjuvant chemoradiotherapy versus radiotherapy alone for women with high-risk endometrial cancer (PORTEC-3): an open-label, multicentre, randomised, phase 3 trial

BACKGROUND About 15% of patients with endometrial cancer have high-risk features and are at increased risk of distant metastases and endometrial cancer-related death. We designed the PORTEC-3 trial to investigate the benefit of adjuvant chemoradiotherapy compared with radiotherapy alone for women with high-risk endometrial cancer. METHODS PORTEC-3 was a multicentre, open-label, randomised, international trial. Women with high-risk endometrial cancer were randomly allocated (1:1) to radiotherapy alone (48·6 Gy) in 1·8 Gy fractions five times a week or chemoradiotherapy (two cycles concurrent cisplatin 50 mg/m(2) and four adjuvant cycles of carboplatin area under the curve [AUC] 5 and paclitaxel 175 mg/m(2)) using a biased coin minimisation procedure with stratification for participating centre, lymphadenectomy, stage of cancer, and histological type. The primary endpoints of the PORTEC-3 trial were overall survival and failure-free survival analysed in the intention-to-treat population. This analysis focuses on 2-year toxicity and health-related quality of life as secondary endpoints; analysis was done according to treatment received. Health-related quality of life was assessed with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) the cervix cancer module and chemotherapy and neuropathy subscales of the ovarian cancer module at baseline, after radiotherapy and at 6, 12, 24, 36, and 60 months after randomisation. Adverse events were graded with Common Terminology Criteria for Adverse Events version 3.0. The study was closed on Dec 20, 2013, after achieving complete accrual, and follow-up remains ongoing for the primary outcomes analysis. This trial is registered with ISRCTN.com, number ISRCTN14387080, and with ClinicalTrials.gov, number NCT00411138. FINDINGS Between Sept 15, 2006, and Dec 20, 2013, 686 women were randomly allocated in the PORTEC-3 trial. Of these, 660 met eligibility criteria, and 570 (86%) were evaluable for health-related quality of life. Median follow-up was 42·3 months (IQR 25·8-55·1). At completion of radiotherapy and at 6 months, EORTC QLQ-C30 functioning scales were significantly lower (worse functioning) and health-related quality of life symptom scores higher (worse symptoms) for the chemoradiotherapy group compared with radiotherapy alone, improving with time. At 12 and 24 months, global health or quality of life was similar between groups, whereas physical functioning scores remained slightly lower in patients who received chemoradiotherapy compared with patients who received radiotherapy alone. At 24 months, 48 (25%) of 194 patients in the chemoradiotherapy group reported severe tingling or numbness compared with 11 (6%) of 170 patients in the radiotherapy alone group (p<0·0001). Grade 2 or worse adverse events were found during treatment in 309 (94%) of 327 patients in the chemoradiotherapy group versus 145 (44%) of 326 patients in the radiotherapy alone group, and grade 3 or worse events were found in 198 (61%) of 327 patients in the chemoradiotherapy group versus 42 (13%) of 326 patients in the radiotherapy alone group (p<0·0001), with most of the grade 3 adverse events being haematological (45%). At 12 and 24 months, no significant differences in grade 3 or worse adverse events were found between groups; only grade 2 or higher sensory neuropathy adverse events persisted at 24 months (25 [10%] of 240 patients in the chemoradiotherapy group vs one [<1%] of 247 patients in the radiotherapy alone group; p<0·0001). INTERPRETATION Despite the increased physician and patient-reported toxicities, this schedule of adjuvant chemotherapy given during and after radiotherapy in patients with high-risk endometrial cancer is feasible, with rapid recovery after treatment, but with persistence of patient-reported sensory neurological symptoms in 25% of patients. We await the analysis of primary endpoints before final conclusions are made. FUNDING Dutch Cancer Society, Cancer Research UK, National Health and Medical Research Council, Project Grant, Cancer Australia Grant, Italian Medicines Agency, and Canadian Cancer Society Research Institute.

Maternal circulating interferon‐γ and interleukin‐6 as biomarkers of Th1/Th2 immune status throughout pregnancy

Aim:  T cells may be classified as T helper type 1 (Th1) cells, which synthesize cytokines inducing cellular immunity, or T helper type 2 (Th2), which synthesize cytokines inducing humoral immunity. According to the Th1/Th2 paradigm, it has been postulated that successful pregnancy induces an immune Th2 bias, but it is not yet clear how Th1 and Th2 systems vary simultaneously throughout the pregnancy.

Cervical ripening using vaginal misoprostol before hysteroscopy: a double-blind randomized trial.

STUDY OBJECTIVE The aim of this study was to evaluate the use of vaginal misoprostol to decrease both the force required to dilate the cervix and the pain experienced during a hysteroscopy. DESIGN Randomized clinical trial (RCT) (Canadian Task Force classification I). SETTING University hospital gynecology clinic. PATIENTS A total of 101 patients needing a diagnostic hysteroscopy. Fifty patients were randomized to the misoprostol group and 51 to the placebo group. Patient characteristics were similar in the 2 groups. INTERVENTIONS Self-administration of 400 microg of vaginal misoprostol or vaginal placebo 12 to 24 hours before a hysteroscopy. MEASUREMENTS AND MAIN RESULTS The force needed to dilate the cervix was assessed by a tonometer, and pain was measured by a visual analog scale. The force to dilate the cervix to 6mm was significantly less in the misoprostol group (5.0 vs 7.5N, p=.02). Pain-related measurements after dilatation of the cervix to 6mm were significantly reduced in the misoprostol group (42.1 vs 57.2, p=.004). The main side effect reported with the use of the drug was pelvic cramping. CONCLUSION The use of 400 microg of vaginal misoprostol 12 to 24 hours before hysteroscopy reduces the pain and the force needed to dilate the cervix, with only mild side effects.

Germline mutations in the breast cancer susceptibility gene PTEN are rare in high-risk non-BRCA1/2 French Canadian breast cancer families

Cowden syndrome is a disease associated with an increase in breast cancer susceptibility. Alleles in PTEN and other breast cancer susceptibility genes would be responsible for ∼25% of the familial component of breast cancer risk, BRCA1 and BRCA2 being the two major genes responsible for this inherited risk. In order to evaluate the proportion of high-risk French Canadian non-BRCA1/BRCA2 breast/ovarian cancer families potentially harboring a PTEN germline mutation, the whole coding and flanking intronic sequences were analyzed in a series of 98 breast cancer cases. Although no germline mutation has been identified in the coding region, our study led to the identification of four intronic variants. Further investigations were performed to analyze the effect of these variants, alone and/or in combination, on splicing and PTEN protein levels. Despite suggestive evidence emerging from in silico analyses, the presence of these intronic variants do not seem to alter RNA splicing or PTEN protein levels. In addition, as loss of PTEN or part of it has been reported, Western blot analysis has also been performed. No major deletion could be identified in our cohort. Therefore, assuming a Poisson distribution for the frequency of deleterious mutation in our cohort, if the frequency of such deleterious mutation was 2%, we would have had a 90% or greater chance of observing at least one such mutation. These results suggest that PTEN germline mutations are rare and are unlikely to account for a significant proportion of familial breast cancer cases in the French Canadian population.

Genetic variants and haplotype analyses of the ZBRK1/ZNF350 gene in high-risk non BRCA1/2 French Canadian breast and ovarian cancer families.

Our current understanding of breast cancer susceptibility involves mutations in the 2 major genes BRCA1 and BRCA2, found in about 25% of high‐risk families, as well as few other low penetrance genes such as ATM and CHEK2. Approximately two‐thirds of the multiple cases families remain to be explained by mutations in still unknown genes. In a candidate gene approach to identify new genes potentially involved in breast cancer susceptibility, we analyzed genomic variants in the ZBRK1 gene, a co‐repressor implicated in BRCA1‐mediated repression of GADD45. Direct sequencing of ZBRK1 entire coding region in affected breast cancer individuals from 97 high‐risk French Canadian breast/ovarian cancer families and 94 healthy controls led to the identification of 18 genomic variants. Haplotype analyses, using PHASE, COCAPHASE and HaploStats programs, put in evidence 3 specific haplotypes which could potentially modulate breast cancer risk, and among which 2 that are associated with a potential protective effect (p = 0.01135 and p = 0.00268), while another haplotype is over‐represented in the case group (p = 0.00143). Further analyses of these haplotypes indicated that a strong component of the observed difference between both groups emerge from the first 5 variants (out of 12 used for haplotype determination). The present study also permitted to determine a set of tagging SNPs that could be useful for subsequent analyses in large scale association studies. Additional studies in large cohorts and other populations will however be needed to further evaluate if common and/or rare ZBRK1 sequence variants and haplotypes could be associated with a modest/intermediate breast cancer risk.

Carboplatin and pegylated liposomal doxorubicin versus carboplatin and paclitaxel in very platinum-sensitive ovarian cancer patients: results from a subset analysis of the CALYPSO phase III trial.

AIM To perform a subset analysis of patients with very platinum-sensitive recurrent ovarian cancer (ROC) enrolled in the phase III CALYPSO trial. PATIENTS AND METHODS The international non-inferiority trial enrolled women with ROC that relapsed >6 months following first- or second-line platinum- and paclitaxel-based therapies. Patients were randomised to CD [carboplatin-pegylated liposomal doxorubicin (PLD)] or CP (carboplatin-paclitaxel) and stratified by treatment-free interval (TFI). In this analysis, patients with a TFI>24 months were analysed separately for progression free survival (PFS), the primary endpoint of CALYPSO, overall survival (OS) and safety. RESULTS A total of 259 very platinum-sensitive patients were included (n=131, CD; n=128, CP). Median PFS was 12.0 months for the CD arm and 12.3 months for CP [HR=1.05 (95% CI, 0.79-1.40); P=0.73 for superiority] and median OS was 40.2 months for CD and 43.9 for CP [HR=1.18 (95% CI 0.85-1.63); P=0.33 for superiority]. Overall response rates were 42% and 38%, respectively (P=0.46). Toxicities were more common with CP versus CD, including grade 3/4 neutropenia (40.8% versus 27.5%; P=0.025), nausea (4.8% versus 3.1%; P=0.47), allergic reaction (8% versus 3.1%; P=0.082) sensory neuropathy (4.8% versus 2.3%; P=0.27) and grade 2 alopecia (88% versus 9.2%; P<0.001). Grade 3/4 thrombocytopenia (12.2% versus 3.2%; P=0.007) and mucositis (2.3% versus 0%; P=0.089) were more common with CD. Grade 3/4 hand-foot syndrome occurred rarely with CD (3 patients versus 0 in CP arm; P=0.089). CONCLUSION CP and CD were equally effective treatment regimens for patients with very platinum-sensitive ROC. The favourable risk-benefit profile suggests carboplatin-PLD as treatment of choice for these patients.

Endometrioid ovarian cancer and endometriotic cells exhibit the same alteration in the expression of interleukin‐1 receptor II: To a link between endometriosis and endometrioid ovarian cancer

Aim:  Endometrioid carcinoma of the ovary is the third most common type of epithelial ovarian cancer. Endometrioid tumors as well as endometriotic implants are characterized by the presence of epithelial cells, stromal cells, or a combination of booth, that resemble the endometrial cells, suggesting a possible endometrial origin of these tumors. Th1 cytokines including interleukin (IL)‐1 have been reported to be involved in both endometriosis and ovarian carcinogenesis. We assessed the expression of receptors of IL‐1 (IL‐1RI and IL‐1RII, the signal transducer and the specific inhibitor of IL‐1, respectively) in cells of the most common subtypes of ovarian cancer compared to endometrial cells.

Expression of interleukin-1 (IL-1) ligands system in the most common endometriosis-associated ovarian cancer subtypes

ObjectivesEndometrioid carcinoma of the ovary is one of the most types of epithelial ovarian cancer associated to endometrioisis. Endometrioid tumors as well as endometriotic implants are characterized by the presence of epithelial cells, stromal cells, or a combination of booth, that resemble the endometrial cells, suggesting a possible endometrial origin of these tumors. Pro-inflammatory cytokines, including interleukin-1 (IL-1) have been reported to be involved in both endometriosis and ovarian carcinogenesis. The major objective of this study was to determine the level expression of IL-1 ligands system (IL-1α, IL-1β and IL-1RA) in the most common subtypes of ovarian cancer cells compared to endometrial cells.MethodsWe used primary endometrial cells, endometrial cell line RL-952 and different subtypes of epithelial ovarian cancer cell lines including TOV-112D (endometrioid), TOV-21G (clear cell) and OV-90 (serous). Immunofluorescence and real-time PCR analysis were used respectively for detecting IL-1 ligands at the levels of cell-associated protein and mRNA. Soluble IL-1 ligands were analyzed by ELISA.ResultsWe demonstrated that IL-1 ligands were expressed by all endometriosis-associated ovarian cancer subtypes and endometrial cells. In contrast to other cancer ovarian cells, endometrioid cells exhibit a specific decrease of cell-associated IL-1RA expression and its soluble secretion.ConclusionEndometrioid ovarian cancer exhibits an alteration in the expression of IL-1RA, a key protector against tumorogenic effects of IL-1. This alteration evokes the same alteration observed in endometriotic cells in previous studies. This suggests a possible link between the endometrium, the tissue ectopic endometriosis and endometrioid ovarian cancer.