Individuals with hereditary cancer syndromes are born with germline genetic variants that significantly increase their lifetime risk of developing multiple cancers. Cancer rates and overall mortality can be reduced with intensive surveillance to facilitate early cancer detection. However, participating in diagnostic imaging and endoscopy surveillance programs is often time-consuming, overwhelming, inconvenient, and anxiety-inducing. To improve this, multi-cancer early detection tests are being developed using cell-free DNA (cfDNA) sequencing analysis to detect cancers with more sensitivity than conventional screening methods. Our community (the CHARM consortium: Cell-free DNA in Hereditary And high-Risk Malignancies) has been exploring the use of cfDNA sequencing in hereditary cancer, and has launched the CHARM2 prospective randomized controlled trial, which is enrolling 1000 participants with Hereditary Breast and Ovarian Cancer, Lynch syndrome, Li-Fraumeni syndrome, Neurofibromatosis type 1 and Hereditary Diffuse Gastric Cancer to improve equitable access, early detection and surveillance for high-risk individuals. All participants will have screening as per conventional syndrome-specific surveillance recommendations. Half the participants (experimental cohort) will also have cfDNA analysis at least three times a year, with abnormal results triggering dedicated clinical imaging and diagnostic evaluation, and heightened surveillance. Vetted by our patient advisors, validated patient-reported outcome and experience measures assessing participant psychosocial outcomes, engagement, and test preferences will be administered to both arms. Our goal is to inform if and how cfDNA analysis could be implemented into routine clinical care and offer a path to equitable and more convenient cancer screening for all high-risk Canadians.

Background: Utilization of palliative care remains low among surgical patients. We aim to characterize general surgeons' perceptions of barriers to access palliative care in British Columbia (BC). Methods: Semi-structured interviews were carried out with a total of 11 surgeons in BC. Interviews were transcribed for thematic analysis via interpretive description. Dominant themes were identified and agreed upon between the authors. Results: Several barriers were identified, which include system and institution, communication and surgical workflow barriers. At the system and institutional level, there were difficulties accessing patient information and continuity of care. Themes in the communication included patient misconceptions about palliative care and communication challenges with consulting services. Surgical workflow barriers influenced the overall perceived role of surgeons when caring for patients with palliative care needs. Conclusion: Understanding surgeons' perspectives on barriers to palliative care is an important step in changing management. This can aid in the development of strategies that ease access to palliative care.

BACKGROUND:The rapid evolution of genetic technologies and utilization of genetic information for clinical decision-making has necessitated increased surgeon participation in genetic counselling, testing, and appropriate referral of patients for genetic services, without formal training in genetics. We performed a scoping review to describe surgeons' knowledge, perceptions, attitudes, and barriers pertaining to genetic literacy in the management of patients who had confirmed cancer or who were potentially genetically at risk. METHODS:We conducted a scoping review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses Extension for Scoping Reviews checklist. We performed a comprehensive literature search, and 2 reviewers independently screened studies for inclusion. These studies included surgeons involved in the care of patients with confirmed gastrointestinal, breast, and endocrine and neuroendocrine cancers, or patients who were potentially genetically at risk for these cancers. RESULTS:We analyzed 17 studies, all of which used survey or interview-based formats. Many surgeons engaged in genetic counselling, testing, and referral, but reported low confidence and comfort in doing so. Knowledge assessments showed lower confidence in identifying genetic inheritance patterns and hereditary cancer syndromes, but awareness was higher among surgeons with greater clinical volume or subspecialty training in oncology. Surgeons felt responsible for facilitating these services and explicitly requested educational support in genetics. Barriers to genetic literacy were identified and catalogued at patient, surgeon, and system levels. CONCLUSION:Surgeons frequently engage in genetics-related tasks despite a lack of formal genetics training, and often report low knowledge, comfort, and confidence in providing such services. We have identified several barriers to genetic literacy that can be used to develop interventions to enhance genetic literacy among surgeons.

Breast cancer is the most commonly occurring cancer in women and has become the most common cancer diagnosed worldwide [...].

# 01. Operative classification of ventral abdominal hernias: new and practical classification {#article-title-2} Ventral hernias of the abdomen are defined as a noninguinal, nonhiatal defect in the fascia of the abdominal wall. Unfortunately, there is not currently a universal classification system

OBJECTIVE:Examine the risks of fractures and osteoporosis after risk-reducing bilateral salpingo-oophorectomy (RRBSO) among women with BRCA1/2 mutations. METHODS:In this retrospective population-based study in British Columbia, Canada, between 1996 to 2017, we compared risks of osteoporosis and fractures among women with BRCA1/2 mutations who underwent RRBSO before the age of 50 (n=329) with two age-matched groups without known mutations: 1) women who underwent bilateral oophorectomy (BO) (n=3,290); 2) women with intact ovaries who had hysterectomy or salpingectomy (n=3,290). Secondary outcomes were: having dual-energy X-ray absorptiometry (DEXA) scan, and bisphosphonates use. RESULTS:The mean age at RRBSO was 42.4 years (range, 26-49) and the median follow-up for women with BRCA1/2 mutations was 6.9 years (range, 1.1-19.9). There was no increased hazard of fractures for women with BRCA1/2 mutations (adjusted hazard ratio [aHR]=0.80; 95% confidence interval [CI]=0.56-1.14 compared to women who had BO; aHR=1.02; 95% CI=0.65-1.61 compared to women with intact ovaries). Among women who had DEXA-scan, those with BRCA1/2 mutations had higher risk of osteoporosis (aHR=1.60; 95% CI=1.00-2.54 compared to women who had BO; aHR=2.49; 95% CI=1.44-4.28 compared to women with intact ovaries). Women with BRCA1/2 mutations were more likely to get DEXA-scan than either control groups, but only 46% of them were screened. Of the women with BRCA1/2 mutations diagnosed with osteoporosis, 36% received bisphosphonates. CONCLUSION:Women with BRCA1/2 mutations had higher risk of osteoporosis after RRBSO, but were not at increased risk of fractures during our follow-up. Low rates of DEXA-scan and bisphosphonates use indicate we can improve prevention of bone loss.

Breast cancer susceptibility gene (BRCA) mutation carriers have an increased risk of breast cancer. Mitigation of this risk can be achieved via surveillance or prophylactic mastectomy with or without breast reconstruction. Those that choose surgery expect to reduce their chance of developing cancer. The purpose of this study was to determine the incidence of patients developing breast cancer prior to surgery and to identify modifiable contributing factors within the patient journey. This is a historical cohort study of all BRCA mutation carriers identified through the British Columbia Cancer Hereditary Cancer Program between 2000 and 2012. Patients were divided into two groups: surveillance (S) and prophylactic mastectomy with immediate breast reconstruction (PM/IBR). The incidence of cancer, time to PM/IBR and patient journeys were analyzed. A total of 333 women were identified. The time to surgery from mutation disclosure was a median of 31 (5.3, 75.7) months. During this period, 6% of patients developed breast cancer compared with a 14% incidence of breast cancer in patients choosing surveillance. The majority of time to surgery was attributed to the period between mutation disclosure and the decision to proceed with surgery. Strategies to facilitate decision-making as well as wait list prioritization and dedicated operative time should be targeted to this population to decrease the number of women developing an interval cancer prior to surgery.

Abstract Background:Based on randomized controlled trials demonstrating no survival benefit of axillary dissection in elderly breast cancer patients, the SSO/Choosing Wisely campaign recommended against the routine use of sentinel lymph node biopsy (SLNB) in clinically node negative patients aged ≥70 with estrogen receptor (ER) positive breast cancer in 2016. SLNB is still performed in >80% of such patients and we have previously shown that at our institution, SLNB positivity influences adjuvant therapy decisions in this population. In this study, we sought to validate the association of SLNB positivity and adjuvant treatment in a larger population-based cohort, and to evaluate the impact of this finding on oncologic outcomes. Methods:The Breast Cancer Outcome Unit (BCOU) prospectively collects demographic, pathologic, treatment and outcomes data on all patients referred to BC Cancer with breast cancer in British Columbia, Canada. Female patients aged ≥70 with newly diagnosed estrogen receptor-positive invasive breast cancer who underwent SLNB from 2010-2016 were included. Patients with HER2-positive disease or those treated with neoadjuvant therapy were excluded. Multivariable analysis was used to assess the effect of SLNB positivity on adjuvant treatment. Overall survival (OS) and breast cancer specific survival (BCSS) were assessed using Kaplan-Meier analysis and Cox regression was used to assess contribution of SLNB positivity and adjuvant treatment. A nomogram was created to model the effect of nodal positivity and adjuvant treatment on BCSS. Results:We identified 2580 patients who met study criteria with a median age of 75 and a median tumor size of 15 mm. SLNB was positive in 23%. Sixty-seven percent of patients had breast conserving surgery (BCS) and 62% of patients had RT (BCS 79%, mastectomy 25%). As systemic therapy 5% of patients had chemotherapy (CT) and 78% of patients had hormone therapy (HT). Use of adjuvant therapies was associated with SLNB positivity: Systemic therapy (HR = 2.4, 95% CI: 1.84-3.14, p <0.0001), RT (HR = 4.94, 95% CI: 3.91-6.25, p <0.0001) and nodal RT (HR = 61.4, 95% CI: 26.6-141.7, p <0.0001). The 5-year OS was 86% and BCSS was 96% with a median follow-up of 4.33 years (95% CI 4.21-4.47 years). There was improved BCSS with receipt of HT (HR 0.51 95% CI 0.301-0.875, p=0.0142) and worse BCSS with grade 3 vs grade 1 disease (HR 4.09, 95% CI 2.06-8.10, p<0.0001). Age, tumor size, status of SLNB and use of RT were not significant prognostic variables. Patients with a positive SLNB who did not receive any adjuvant therapy had lower BCSS (HR 3.22 95% CI 1.235-8.418, p=0.0168) than those with a negative SLNB. However, amongst those who received any combination of CT, HT and RT, there was no significant difference in BCSS regardless of nodal status. A nomogram was developed incorporating tumor size, grade, SLNB status and adjuvant treatment. Using the nomogram, patients aged 75-79 with T1, grade 1-2 tumors, with or without positive SLNB and treated with or without adjuvant therapy had 5-year BCSS ≥95%. The nomogram also indicated that 5-year BCSS was similar for patients with positive and negative SLNB for all combinations of tumor features when patients received HT. Conclusions:In this modern, population-based cohort of patients over 70 with ER-positive breast cancer, 5-year BCSS was excellent at 96%. Although the use of adjuvant treatment was associated with a positive SLNB, BCSS was not changed based on nodal status when patients received HT. Our results support the Choosing Wisely recommendations; SLNB can be safely omitted in elderly patients willing to take HT, and we advocate that SLNB can be omitted in low-risk patients aged ≥75 even in the absence of planned HT. Citation Format: Elaine McKevitt, Rona Cheifetz, Kimberly DeVries, Alison Laws, Rebecca Warburton, Lovedeep Gondara, Caroline Lohrisch, Alan Nichol. Sentinel node biopsy should not be routine in older patients with ER positive breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD4-02.

Objective. Examine the risk of cardiovascular disease (CVD) following risk reducing bilateral salpingo-oophorectomy (RRBSO) among women with BRCA mutations. Methods. In this retrospective population-based study in British Columbia, Canada, between 1996 and 2017, we compared the risk of CVD among women with known BRCA mutations who underwent RRBSO before the age of 50 (n = 360) with two groups of age-matched women without known BRCA mutations: 1) women who underwent bilateral oophorectomy (BO) for benign conditions (n = 3600); and, 2) women with intact ovaries who had hysterectomy or salpingectomy (n = 3600). Our primary outcome was CVD (a composite (any of) myo-cardial infarction, heart failure, and/or cerebrovascular disease). Secondary outcomes included a diagnostic code for predisposing conditions (hypertension, dyslipidemia, and/or diabetes mellitus), and use of cardioprotective medications (statins and/or beta-blockers). Results. We report no significant increased risk for CVD between women with BRCA mutations and women who underwent BO (aHR = 1.08, 95%CI: 0.72-1.62), but women with BRCA mutations were less likely to be diagnosed with predisposing conditions (aHR = 0.69, 95%CI: 0.55-0.85). Compared to women without BRCA mutations with intact ovaries who underwent hysterectomy or salpingectomy, women with BRCA mutations had significantly in-creased risk for CVD (aHR = 1.82, 95%CI: 1.18-2.79) and were less likely to be diagnosed with predisposing con-ditions (aHR = 0.78, 95%CI: 0.62-0.97) and to fill cardioprotective medications (aHR = 0.88, 95%CI: 0.64-1.22). Conclusion. Our results suggest an opportunity for improved prevention of CVD in women with BRCA muta-tions after prophylactic oophorectomy. Despite the observed lower prevalence of predisposing conditions for CVD and lesser use of cardioprotective medications, this population did not have a lower rate of CVD. (c) 2021 Elsevier Inc. All rights reserved.

Introduction: A breast cancer synoptic operative report was developed using a modified Delphi process Methods: Data from the British Columbia Cancer Breast Cancer Outcomes Unit (BCOU) was used to analyze the association between the completion of a synoptic operative report and reporting of operative details and The American Society of Breast Surgeons quality indicators. Results: 3662 patients had surgery for breast cancer by 185 surgeons. 2281 reports were narrative and 1007 synoptic. Requested surgical details were more commonly reported with synoptic reports for both posterior (96 vs 58%, p < 0.0001) and anterior margins (96 vs 5%, p < 0.0001). This was true for high and low volume surgeons. Quality Indicators were higher in those cases with an associated synoptic report for high and low volume surgeons. Conclusion: Communication of operative details is improved with synoptic reporting. Investment in platforms to facilitate synoptic reporting could improve patient care through improved multidisciplinary communication. (C) 2020 Elsevier Inc. All rights reserved.

Background: The majority of breast cancers are thought to occur sporadically, with approximately 5% thought to be due to inherited susceptibility to cancer. The most commonly mutated genes predisposing women to breast cancer are BRCA1 and BRCA2. The Hereditary High-Risk Clinic at BC Cancer organizes breast screening and provides assessment and management recommendations for women with hereditary breast cancer risk. A study was done to ascertain the effectiveness of the clinic and identify areas of need. Methods: A retrospective chart review was conducted using BC Cancer data for all patients seen at the High-Risk Clinic from 1997 to 31 July 2015. Study subjects included women with confirmed gene mutations that predispose them to increased risk for breast cancer and women who were untested but had a first-degree relative with a confirmed mutation. Patient data were anonymized prior to analysis. Results: The study population included 654 women first seen in the clinic at a mean age of 42 years. Of these, 151 patients had previous diagnoses for cancer, including 142 breast cancers. During management of these women at the clinic, a total of 80 new breast tumors were identified and 77 of these were found to be malignant. Diagnosis occurred at a mean age of 48 years. The majority of new cancers were identified by either MRI or mammographic screening. During the study period, 38% of patients underwent prophylactic mastectomy and over 80% of patients older than 40 completed bilateral salpingo-oophorectomy. The mean age of patients undergoing bilateral mastectomy was 45 (22 to 79) years, while the mean age of patients undergoing bilateral salpingo-oophorectomy was 47 (26 to 77) years. Discussion: Women with genetic risk for breast cancer require enhanced screening that includes annual MRI and mammography. The High-Risk Clinic is providing hereditary high risk women in BC with diagnostic and prophylactic services, and achieving rates of risk-reducing surgery comparable to those in the literature. However, 53% of women attending the clinic were older than 40 at their first visit and so may have missed the full benefit of risk reduction that might be achieved with earlier referral. In future, the centralization of care in the High-Risk Clinic and ongoing data collection should provide an opportunity to evaluate new imaging modalities, long-term outcomes of risk-reducing surgery, and new risk-reducing strategies.

The process leading to diagnosis of breast cancer has changed over the past 20 years with improvements in diagnostic imaging and a shift from surgical biopsy to image-guided core needle biopsy. History-taking and physical examination, diagnostic breast imaging, and biopsy are essential when evaluating breast concerns, as is the use of the Breast Imaging Reporting and Data System (BI-RADS) when describing findings. Assessment of the concordance between physical examination findings, imaging, and biopsy pathology is also essential to diagnosis, and minimizes surgical intervention. The roles of the primary care physician, radiologist, and surgeon have changed as well over the past 20 years, meaning that the optimal management of patients with breast concerns is now multi-disciplinary. Referring physicians have different roles in navigating patients through the diagnostic system in different communities.

# 01: Iron deficiency in bariatric surgery patients — a single-centre experience over 5 years {#article-title-2} As the prevalence and severity of obesity have increased in Canada, so too has the demand for bariatric surgery. The objective of this study was to determine the incidence of

3590 Background: In 2009, pts with M1 colorectal cancer were divided into two subsets for the American Joint Committee on Cancer (AJCC) 7th edition. Pts with metastases (mets) confined to one organ or site at initial diagnosis became stage M1a while multiple sites or peritoneal mets became M1b. The objectives of the study are to evaluate the impact of site of mets and M1a/b staging among pts with M1 colorectal cancer. Methods: All pts referred to the BC Cancer Agency from 1999-2007 with newly diagnosed M1 colon or rectal cancer were included. Demographic, treatment, and outcome data were prospectively collected. The prognostic impact of individual sites of mets was assessed by hazard ratio estimates from univariate Cox models. Multivariable Cox proportional-hazards models were used to determine variables associated with overall survival in the entire cohort and in those undergoing resection of their primary tumor. Results: 2,049 pts with M1 disease were included. Median age was 66 years; 71% had colonic origin; 70% had their primary tumor resected; and 69% received chemotherapy. In univariate analysis, solitary mets were associated with improved survival. In multivariable analysis, M1a/b status still had significant prognostic effect. The effect remained significant in the subgroup analysis of pts with resected primary tumors when histology, T and N stage were included. Conclusions: Pts with solitary mets, including peritoneum, have superior overall survival as compared to those with multiple sites of mets. AJCC 7th edition staging that includes M1a/b provides significant prognostic information and should be considered in clinical practice and trials of pts with M1 disease who otherwise have few prognostic factors. [Table: see text]

BACKGROUND: We examined practice referral patterns for primary retroperitoneal sarcoma (PRS) in British Columbia (BC) and associations between the timing of referral to tertiary care and patient outcomes. METHODS: Using ICD-10 coding, the Cancer Agency Information System was used to identify patients with PRS from 2000 to 2009 who had been referred to tertiary care and had undergone a surgical resection. RESULTS: Eighty-two patients were included. Those referred before surgery were significantly more likely to receive a complete resection (P = .0002) and adjuvant radiation (P = .0000) compared with patients referred after surgery. Referral before surgery was associated with a significantly increased overall (P = .0619) and recurrence-free (P = .0400) survival; however, in the multivariate model this was not significant. CONCLUSIONS: Referral before surgery is associated with higher rates of complete resection and the use of adjuvant radiation; furthermore, it is associated with prolonged survival in the univariate but not in the multivariate model. (c) 2012 Elsevier Inc. All rights reserved.