Peter Bryson

Identification of the IGF1/PI3K/NF κB/ERK gene signalling networks associated with chemotherapy resistance and treatment response in high-grade serous epithelial ovarian cancer

BackgroundResistance to platinum-based chemotherapy remains a major impediment in the treatment of serous epithelial ovarian cancer. The objective of this study was to use gene expression profiling to delineate major deregulated pathways and biomarkers associated with the development of intrinsic chemotherapy resistance upon exposure to standard first-line therapy for ovarian cancer.MethodsThe study cohort comprised 28 patients divided into two groups based on their varying sensitivity to first-line chemotherapy using progression free survival (PFS) as a surrogate of response. All 28 patients had advanced stage, high-grade serous ovarian cancer, and were treated with standard platinum-based chemotherapy. Twelve patient tumours demonstrating relative resistance to platinum chemotherapy corresponding to shorter PFS (< eight months) were compared to sixteen tumours from platinum-sensitive patients (PFS > eighteen months). Whole transcriptome profiling was performed using an Affymetrix high-resolution microarray platform to permit global comparisons of gene expression profiles between tumours from the resistant group and the sensitive group.ResultsMicroarray data analysis revealed a set of 204 discriminating genes possessing expression levels which could influence differential chemotherapy response between the two groups. Robust statistical testing was then performed which eliminated a dependence on the normalization algorithm employed, producing a restricted list of differentially regulated genes, and which found IGF1 to be the most strongly differentially expressed gene. Pathway analysis, based on the list of 204 genes, revealed enrichment in genes primarily involved in the IGF1/PI3K/NF κB/ERK gene signalling networks.ConclusionsThis study has identified pathway specific prognostic biomarkers possibly underlying a differential chemotherapy response in patients undergoing standard platinum-based treatment of serous epithelial ovarian cancer. In addition, our results provide a pathway context for further experimental validations, and the findings are a significant step towards future therapeutic interventions.

Initial Evaluation and Referral Guidelines for Management of Pelvic/Ovarian Masses

OBJECTIVES To optimize the management of adnexal masses and to assist primary care physicians and gynaecologists determine which patients presenting with an ovarian mass with a significant risk of malignancy should be considered for gynaecologic oncology referral and management. OPTIONS Laparoscopic evaluation, comprehensive surgical staging for early ovarian cancer, or tumour debulking for advanced stage ovarian cancer. OUTCOMES To optimize conservative versus operative management of women with possible ovarian malignancy and to optimize the involvement of gynaecologic oncologists in planning and delivery of treatment. EVIDENCE Published literature was retrieved through searches of PubMed or MEDLINE, CINAHL, and the Cochrane Library, using appropriate controlled vocabulary and key words. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. Grey (unpublished) literature was identified by searching the web sites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. RECOMMENDATIONS 1. Primary care physicians and gynaecologists should always consider the possibility of an underlying ovarian cancer in patients in any age group who present with an adnexal or ovarian mass. (II-2B) 2. Appropriate workup of a perimenopausal or postmenopausal woman presenting with an adnexal mass should include evaluation of symptoms and signs suggestive of malignancy, such as persistent pelvic/abdominal pain, urinary urgency/frequency, increased abdominal size/bloating, and difficulty eating. In addition, CA125 measurement should be considered. (II-2B) 3. Transvaginal or transabdominal ultrasound examination is recommended as part of the initial workup of a complex adnexal/ovarian mass. (II-2B) 4. Ultrasound reports should be standardized to include size and unilateral/bilateral location of the adnexal mass and its possible origin, thickness of septations, presence of excrescences and internal solid components, vascular flow distribution pattern, and presence or absence of ascites. This information is essential for calculating the risk of malignancy index II score to identify pelvic mass with high malignant potential. (IIIC) 5. Patients deemed to have a high risk of an underlying malignancy should be reviewed in consultation with a gynaecologic oncologist for assessment and optimal surgical management. (II-2B).

Canadian Consensus Guidelines on Human Papillomavirus

OBJECTIVE To serve as a guideline for health care providers on the use of continuous and extended combined hormonal contraception regimens, to prevent pregnancy, and to delay menses that affect health-related quality of life. OPTIONS All combined hormonal contraceptive methods available in Canada that may be used in a continuous or extended regimen are reviewed, and the implications are discussed. OUTCOMES Efficacy of cited regimens and assessment of their side effects, patient safety, medical usage and non-contraceptive benefits, cost-effectiveness, and availability in Canada. Indications for patient counselling are also provided. EVIDENCE Medline, PubMed, and Cochrane Database were searched for articles published in English between 1977 and May 2007. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. VALUES The quality of evidence is rated using the criteria described by the Canadian Task Force on Preventive Health Care (Table 1). BENEFITS, HARMS, AND COSTS The guideline is intended to help reduce unintended pregnancies and improve health-related quality of life in women who find their menses problematic. Increased awareness and empowerment of women, their partners, and health care professionals will improve their ability to make appropriate choices between continuous or extended and cyclic usage of these regimens. SPONSORS The development of this guideline has been supported by unrestricted grants from Bayer HealthCare Pharmaceuticals, Janssen Ortho, Organon Canada Ltd., Paladin Labs Inc., Pfizer Canada Inc., and Wyeth Pharmaceuticals.Objective: To promote guidelines for health care providers on the key aspects of HPV infection and the management of HPV-related disease in the new era of vaccine availability.

Management of squamous cell cancer of the vulva.

Abstract Objectives To review and make recommendations regarding the management of early and advanced squamous cell cancer of the vulva. Options Radical vulvectomy and groin dissection or more conservative surgery in early squamous cell vulvar cancer; chemotherapy and radiation followed by consideration of surgery in advanced disease. Outcomes Risk of inguinal lymph node metastases, risk of tumour recurrence, patient morbidity, patient survival. Evidence Follows the quality of evidence assessment of the Canadian Task Force on the Periodic Health Examination (Table 1). Recommendations 1.Stage IA lesions (≤ 2cm diameter and≤1mm stromal invasion) can be managed by radical local tumour excision without inguinofemoral node dissection. (II-2B) 2.Stage IB unilateral lesion (≤ 2cm diameter, > 1mm stromal invasion and ≥ 1cm from the midline) is treated by radical wide local excision completed by an ipsilateral inguinofemoral node dissection; a central lesion (within 1cm from the midline) requires bilateral inguinofemoral node dissection. (II-2B) 3.Patients with either three or more micrometastases in the groin with node size>10mm, with extracapsular spread, or with bilateral microscopic groin metastases should receive postoperative bilateral groin and pelvic radiation. (II-2B) 4.Advanced cancer of the vulva should be treated with primary radiation and concomitant chemotherapy, followed by consideration of surgical resection. (II-2B)

Outcomes of a Decade of Routine Cervical Screening in a Canadian Adolescent Obstetrics Clinic

OBJECTIVE New recommendations from the Ontario Cervical Cancer Screening Program indicate that initiation of screening should be delayed to age 21. However, there is sparse evidence pertaining to pregnant adolescents. Our objective was to determine whether early cervical cancer screening in pregnant adolescents confers an advantage over delayed screening in the prevention of cervical carcinoma. METHODS We conducted a retrospective cohort study of cervical cancer screening in all pregnant adolescents receiving antenatal care through an obstetrics clinic for adolescents between 2000 and 2010. Clinic attendees had an antenatal and/or postpartum Pap smear, with follow-up according to standard recommendations. Results were recorded together with information on regression, persistence, or progression of abnormal cytology, colposcopy referrals, and cervical biopsies. There is a single regional colposcopy clinic. RESULTS At least one Pap smear result was documented in 365 of the 388 patients. Of these 365 smears, 88 had abnormal cytology, 76 (86.4%) of which were reported as atypical cells of undetermined significance/low-grade squamous intraepithelial lesion, 11 (12.5%) high-grade squamous intraepithelial lesion (HSIL), and one atypical glandular cells (1.1%). Follow-up cytology was available for 78 patients. No patient lost to follow-up had subsequent referrals for colposcopic assessment in the region. Overall, cytologic abnormalities regressed in 75 (96.1%), persisted in two (2.6%), and progressed in one patient (1.3%). Twenty-three patients (of 365) required a total of 68 colposcopy visits and 17 biopsies, but ultimately only three loop electrosurgical excision procedures (LEEPs) and one laser vaporization were performed. Only one LEEP in a 20-year-old demonstrated HSIL. CONCLUSION This population of pregnant adolescents had a high incidence of low-grade cervical abnormalities with a high rate of regression. Routinely screening these pregnant adolescents resulted in numerous repeat visits, repeat Pap smears, and colposcopy referrals, and led to patient anxiety and systemic costs. Not a single case of cervical cancer was prevented that would not otherwise have been identified by adherence to the new guidelines.

Abstract A53: Biomarkers of chemotherapy resistance in serous epithelial ovarian cancer identified by integrative genomic and transcriptomic analysis

Resistance to platinum-based chemotherapy remains a major impediment in the treatment of serous epithelial ovarian cancer. The objective of this study was to use gene expression and copy number profiling to delineate major deregulated pathways and biomarker networks associated with the development of intrinsic chemotherapy resistance with exposure to standard first-line therapy for ovarian cancer. The study cohort comprised 28 high grade serous ovarian cancer patients divided into two groups based on their varying sensitivity to first-line chemotherapy using progression free survival (PFS) as a surrogate of response. Twelve patient tumors demonstrating relative resistance to platinum based chemotherapy corresponding to shorter PFS (less than 6 months) were compared to 16 tumors from platinum-sensitive patients (PFS more than 18months). Molecular profiling was performed using Affymetrix high-resolution microarray platforms to permit global comparisons of gene expression levels and copy number profiles between tumors from the resistant group with the sensitive group. Microarray data analysis using statistical methods revealed a set of 204 discriminating genes of which expression levels may be influencing differential chemotherapy response between the two groups. Pathway analysis of the differentiating genes showed IGF1 network to be significantly altered between the two groups in addition to PI3K, NFkB, distinguishing the chemotherapy resistant with the sensitive group. Copy number analysis showed differences in the chromosomal regions, 4q31.22, 5q13.2, 9p24.3, 2p23.2, 16q21, 6q14.1, 7p22.3, 12p13 and Xq. Integrative copy number and gene expression profiling will delineate the drivers of chemotherapy resistance in patients undergoing standard platinum-based treatment of ovarian cancer. Future studies to validate these markers are necessary to apply this knowledge to biomarker-based clinical trials. Citation Format: Madhuri Koti, Robert J. Gooding, Paulo Nuin, Alexandria Haslehurst, Colleen Crane, Johanne Weberpals, Timothy Chids, Peter Bryson, Moyez Dharsee, Kenneth R. Evans, Harriet E. Feilotter, Paul C. Park, Jeremy A. Squire. Biomarkers of chemotherapy resistance in serous epithelial ovarian cancer identified by integrative genomic and transcriptomic analysis. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr A53.

Abstract 810: Integrative genomic and transcriptomic analysis in idenfitication of biomarkers of chemoresistance in serous epithelial ovarian cancer.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Resistance to platinum-based chemotherapy remains a major impediment in the treatment of serous epithelial ovarian cancer. The objective of this study was to use gene expression and copy number profiling to delineate major deregulated pathways and biomarker networks associated with the development of intrinsic chemotherapy resistance with exposure to standard first-line therapy for ovarian cancer. The study cohort comprised 28 high grade serous ovarian cancer patients divided into two groups based on their varying sensitivity to first-line chemotherapy using progression free survival (PFS) as a surrogate of response. Twelve patient tumors demonstrating relative resistance to platinum based chemotherapy corresponding to shorter PFS (less than 6 months) were compared to 16 tumors from platinum-sensitive patients (PFS more than 18months). Molecular profiling was performed using Affymetrix high-resolution microarray platforms to permit global comparisons of gene expression levels and copy number profiles between tumors from the resistant group with the sensitive group. Microarray data analysis revealed a set of 227 discriminating genes of which expression levels may be influencing differential chemotherapy response between the two groups. Pathway analysis of these genes showed the,PI3K,NFkB and IGF1 networks as some of the significant networks distinguishing the chemotherapy resistant with the sensitive group. Copy number analysis performed using Nexus copy number version 6.1 revealed differences in the chromosomal regions, 4q31.22, 5q13.2, 9p24.3, 2p23.2, 16q21, 6q14.1, 7p22.3, 12p13 and Xq. Integrative copy number and gene expression profiling will delineate the drivers of chemotherapy resistance in patients undergoing standard platinum-based treatment of ovarian cancer. Future studies to validate these markers are necessary to apply this knowledge to biomarker-based clinical trials. Citation Format: Madhuri Koti, Robert J. Gooding, Paulo Nuin, Alexandria Haslehurst, Colleen Crane, Johanne Weberpals, Timothy Childs, Peter Bryson, Moyez Dharsee, Kenneth Evans, Harriet E. Feilotter, Paul C. Park, Jeremy A. Squire. Integrative genomic and transcriptomic analysis in idenfitication of biomarkers of chemoresistance in serous epithelial ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 810. doi:10.1158/1538-7445.AM2013-810

Abstract 3004: Biomarker identification through integrative bioinformatics analysis of serous epithelial ovarian cancer tumor samples

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Ovarian cancer is the leading cause of death from gynecological malignancies and the fifth major cancer in women in the world. Once diagnosed, ovarian cancer is usually treated by cytoreductive surgery followed by platinum and taxane-based chemotherapeutic drugs. However, resistance to chemotherapy is a major impediment in management of serous epithelial ovarian cancer (SEOC). We hypothesize that a multifaceted view of the alterations taking place at multiple cellular levels using molecular profiling technologies will offer insight into the mechanisms which play key roles in drug resistant ovarian carcinomas. Also, the application of appropriate bioinformatic and statistical data processing and analysis is of utmost importance in identification of key drug resistance pathways. Current study is performed on 25 high-grade serous epithelial ovarian tumor tissue samples from patients that demonstrated favorable, or unfavorable response to chemotherapy treatment. Four different microarray platforms were used for molecular profiling of the full sample cohort at different molecular levels, namely: Single Nucleotide Polymorphisms (SNP), mRNA expression, miRNA expression and promotor tiling arrays (methylation)., Integrative and systematic analyses using up-to-date statistical approaches, such as empirical Bayes, AUC, SAM, permuted t-test and lassoed PCA, among others, have been employed on these large datasets obtained through the various high-throughput platforms. Preliminary mRNA expression analysis identified an enrichment of upregulated genes involved in cellular growth and proliferation, cellular development as well as differential gene expression changes in the TGFB1, TNF, PI3K, IFNG networks, between the chemotherapy responsive and unresponsive groups. The major molecular and cellular functions associated were cell-to-cell signaling, molecular transport and cellular movement. Differences were also seen in the, CTNNB1, LH and FSH networks as analysed by Ingenuity Pathway Analysis. Additionally, genes involved in activation of NFκB pathway showed differential expression in the two groups. Furthermore, our ongoing development of a streamlined database in which the multiple data types obtained from our statistical analyses are stored, will allow for localized or genome wide querying across the multiple levels of biological data. These approaches and software will potentially elucidate the synergistic roles that the various biological levels play in the deregulation of pathways involved in primary chemoresistance. Our research findings will lead to the determination of putative candidates for diagnostic and prognostic biomarkers that can be targeted for development of treatment regimens for the treatment of SEOC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3004. doi:1538-7445.AM2012-3004

Abstract 3645: Integrative molecular profiling in serous epithelial ovarian cancer for identification of biomarkers of chemoresistance

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Ovarian cancer is the fifth leading cause of death due to gynecological cancers in women in the western world. Development of primary resistance to carboplatin and paclitaxel poses a major challenge in the management of serous epithelial ovarian cancer. To identify the molecular mechanisms underlying the development of instrinsic resistance upon exposure to standard first-line therapy for ovarian cancer, we used microarrays to profile the 1) copy number alteration and SNP, 2) mRNA, 3) miRNA and 4) methylation signatures in a cohort comprising 11 chemoresistant and 14 chemosensitive tumour samples. Copy number analysis showed significant copy number alterations in the chemoresistant group (gains on chromosomal regions, 4q, 6q, 8p, 8q, 19q, 7q and 22q; losses on 8p and 10q) compared to the sensitive group. Gene expression data analysis using R/bioconductor revealed a set of 248 discriminating genes in the two cohorts. Pathway analysis of these genes using Ingenuity Pathway Analysis revealed enrichment in genes primarily involved in epithelial to mesenchymal transition and PI3 Kinase pathway. Additionally, genes related to the pro-inflammatory cytokine pathways, as well as drug transport demonstrated significant differential expression between the two groups. Ongoing concurrent comparative analyses of miRNA profiles within this cohort have also identified several differentially expressed transcripts including mir-34b, mir-155, mir-214, mir-200c and mir-143. Some of these miRNAs have been earlier reported to be associated with tumour progression. Further integrated analysis will elucidate the synergistic roles that the genetic and epigenetic alterations in the deregulation of these and other pathways involved in primary chemoresistance. Our research findings will yield diagnostic and prognostic biomarkers that will lead to development of specific treatment regimens for the improved control of serous epithelial ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3645. doi:1538-7445.AM2012-3645

Abstract 3155: Identification of biomarkers of chemoresistance in serous epithelial ovarian cancer by integrative molecular profiling

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Development of primary resistance to carboplatin and paclitaxel pose a major challenge in the management of ovarian cancer. To identify the molecular mechanisms underlying this process, we used microarrays to profile the 1) copy number alteration and SNP, 2) mRNA, 3) miRNA and 4) methylation signatures in 11 chemoresistant and 13 sensitive tumour samples, as defined by the RECIST criteria. The profiles are analyzed by Bayes statistics, based on R/Bioconductor packages, and the relevant pathways determined using the Ingenuity Pathway Analysis. The data from each array platforms are integrated using bioinformatic analytical and visual tools developed in house to not only decipher the most critical biological pathways, but also to identify the molecular mechanisms driving the pathways. Analysis to date identified the metabolic network involving HNRNPC, JAK1, Erbb2, ARF1, among others, which converge to deregulate the PI3K pathway. Interestingly, this is consistent with PTEN loss which is frequently observed in serous low grade tumours. The complexity of this pathway is reflected by its implication in multiple biological functions including growth promoting pathways, proliferation, differentiation, anti-apoptosis, tumorigenesis and angiogenesis. The integrated analysis will dissect and elucidate the roles that the CNA, SNP, methylation and miRNA play in the deregulation of this and other pathways involved in primary chemoresistance. Our research findings will yield diagnostic and prognostic biomarkers that will lead to development of specific treatment regimens for the improved control of serous epithelial ovarian cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3155. doi:10.1158/1538-7445.AM2011-3155