The role of surgeon specialty in management and survival of malignant ovarian germ cell tumors: A population-based study.

OBJECTIVES: The aim of this study is to describe management and survival in adult patients with malignant ovarian germ cell tumors (MOGCT) undergoing surgery by general gynecologists (GG) versus gynecologic oncologists (GO). METHODS: This is a population-based retrospective cohort study, including patients (age ≥ 18 years old) with MOGCT identified in the provincial cancer registry of Ontario, (1996-2020). Baseline characteristics, surgical and chemotherapy treatment were compared between those with surgery by GG or GO. Cox proportional hazards (CPH) model was used to determine if surgeon specialty was associated with overall survival (OS). RESULTS: Overall, 363 patients were included. One-hundred and sixty (44%) underwent surgery by GO and 203 (56%) by GG. There were higher rates of stage II-IV in the GO group (27.5% vs 3.9%, p < 0.001, and higher proportion of chemotherapy (64.4% vs 37.4%, p < 0.0001). Five-year OS was 90% and 93% in the GO vs GG groups, respectively (p = 0.39). CPH model showed factors associated with increased risk of death were older age at diagnosis (HR 1.09, 95% CI 1.07-1.12) and chemotherapy (HR 3.12, 95% CI 1.44-6.75). Surgeon specialty was not independently associated with all-cause death (HR 1.04, 95% 0.51-2.15, p = 0.91). CONCLUSIONS: In this group of MOGCT, 5-year OS was not significantly different between patients having surgery by GO compared to GG. Nevertheless, survival rates were lower than expected in the GG group despite their low-risk features. Further exploration is warranted regarding the reasons for this and whether patients with suspected MOGCT may benefit from early assessment by GO for optimal management.

Grade and Estrogen Receptor Expression Identify a Subset of No Specific Molecular Profile Endometrial Carcinomas at a Very Low Risk of Disease-Specific Death.

Endometrial carcinoma (EC) can be divided into 4 prognostic molecular subtypes, and no specific molecular profile (NSMP) type is the most commonly occurring type (∼50%). Although described as having an intermediate to favorable prognosis, this subtype encompasses pathologically and molecularly diverse tumors. We aimed to identify factors associated with outcomes within the NSMP ECs that might be used to stratify prognosis and direct treatment. Clinicopathologic, immunohistochemical, and genetic features of a large series of NSMP EC were used to identify parameters that could identify the subset associated with a very favorable outcome (disease-specific death rate <5% at 5 years, termed low-risk NSMP). A total of 1110 NSMP ECs were profiled. In a univariate analysis, stage, grade, lymphovascular invasion, estrogen receptor (ER) and progesterone receptor (PR) expression, L1CAM overexpression, and mutations in PIK3CA were associated with disease-specific survival. Two critical features, grade and ER expression, identified a low-risk NSMP subset (grade 1-2, ER-positive [>1%], 84% of cases), which showed a 5-year disease-specific death rate of 1.6% across all stages and 1.4% within stage I. The remaining cases (high-risk NSMPs, grade 3, and/or ER-negative status) were responsible for most of the disease-specific deaths (disease-specific death rate at 5 years, 22.9%; hazard ratio compared with that of low-risk NSMPs: 16.3; 95% CI, 8.4-31.7). Within NSMP EC, the low-risk and high-risk categories were of prognostic significance independent of the stage on a multivariate analysis. Low-grade and ER-positive NSMP ECs are a homogeneous low-risk group associated with an exceptionally favorable prognosis in which de-escalation and/or endocrine therapy strategies can be applied. Grade 3 and/or ER-negative status identifies a high-risk NSMP subset, including rare high-grade histotypes (eg, clear cell, dedifferentiated, and mesonephric-like), responsible for most NSMP-related deaths. Subclassification of NSMPs allows for the category of low-risk EC molecular subtypes to be dramatically expanded because it now includes both POLEmut and the much more common low-risk NSMP EC.

Apixaban for extended postoperative thromboprophylaxis in gynecologic oncology patients undergoing laparotomy.

INTRODUCTION: Venous thromboembolic events represent the second most frequent cause of mortality in cancer patients. Recent literature shows that direct oral anticoagulants (DOAC) are at least as effective and safe as low molecular weight heparin for postoperative thromboprophylaxis. However, this practice has not been broadly adopted in gynecologic oncology. The aim of this study was to evaluate clinical effectiveness and safety of apixaban for extended thromboprophylaxis in comparison to enoxaparin after laparotomies for gynecologic oncology patients. METHODS: The Gynecologic Oncology Division at a large tertiary center transitioned from enoxaparin 40 mg daily to apixaban 2.5 mg BID for 28 days after laparotomies for gynecologic malignancies in November 2020. This real-world study compared patients post-transition (November 2020 to July 2021 (n = 112)) to a historical cohort (January to November 2020 (n = 144)), using the institutional National Surgical Quality Improvement Program (NSQIP) database. All Canadian gynecologic oncology centers were surveyed to assess postoperative DOAC utilization. RESULTS: Patient characteristics were similar between groups. No difference was found between total venous thromboembolism rates (4% vs. 3%, p = 0.49). No difference was found in postoperative readmission (5% vs. 6%, p = 0.50). Of the 7 readmissions in the enoxaparin group, one was due to bleeding requiring transfusion; there were no readmissions for bleeding in the apixaban group. No patient required a reoperation for bleeding. Thirteen percent of the 20 Canadian centers have transitioned to extended apixaban thromboprophylaxis. CONCLUSIONS: Apixaban for 28-day postoperative thromboprophylaxis was found to be an effective and safe alternative to enoxaparin after laparotomies in a real-world cohort of gynecologic oncology patients.

Safety of fertility sparing management in invasive mucinous ovarian carcinoma.

BACKGROUND: The aim of the study was to evaluate the safety of fertility-sparing surgery in invasive mucinous ovarian carcinomas (MOC). METHODS: Retrospective review was performed of MOCs diagnosed between 1999 and 2019 at two tertiary cancer centers. Pathology was reviewed to rule out metastasis from gastrointestinal tract. The demographics and survival outcomes were compared between women who underwent fertility-sparing surgery and those who underwent radical surgery (at least hysterectomy, bilateral salpingo-oophorectomy +/- staging). Cox proportional hazard models were constructed to evaluate the effect of fertility sparing surgery on survival. RESULTS: Of 134 with stage I disease, 42 (31%) underwent fertility-sparing surgery with unilateral salpingo-oophorectomy. Compared to women who underwent radical surgery, these women were younger with low grade, early-stage disease. Two patients (5%) in the fertility-sparing cohort experienced a recurrence and 1 of these 2 patients died due to disease progression. There was no difference in either OS or RFS between those that underwent fertility-sparing surgery and radical surgery. In a multivariable analysis adjusting for age and use of adjuvant chemotherapy, fertility-sparing surgery was not significantly associated with OS (HR 0.18; 95% CI 0.01-2.78) or RFS (HR 0.19; 95% CI 0.03-1.45). There were 4 patients (9%) with documented full-term delivery with median interval to conception of 11 months. CONCLUSIONS: Fertility-sparing surgery in stage I MOC is not associated with worse outcomes compared to radical surgery and is reasonable to offer to those with early stage disease who wish to retain fertility.

Diagnostic accuracy of frozen section and patterns of nodal spread in high grade endometrial cancer: A secondary outcome of the SENTOR prospective cohort study.

OBJECTIVES: The study aimed to define the accuracy of intraoperative frozen section (FS) for the detection of metastases in sentinel lymph node biopsy (SLNB) and describe the pattern of lymph node (LN) spread and relation to molecular classifiers in patients with high-grade endometrial cancer (EC). METHODS: We performed a secondary outcome of clinicopathologic data from the Sentinel Lymph Node Biopsy versus Lymphadenectomy for Intermediate- and High-Grade Endometrial Cancer Staging (SENTOR) prospective cohort study evaluating SLNB in patients with clinical stage I high-grade EC (ClinicalTrials.gov ID: NCT01886066). The primary outcome was the sensitivity of FS of the sentinel lymph node (SLN) specimen, compared to a standardized ultrastaging protocol. Secondary outcomes included the pattern and characteristics of LN spread. RESULTS: There were 126 patients with high-grade EC with a median age of 66 years (range:44-86) and a median Body Mass Index (BMI) of 26.9 kg/m2 (range:17.6-49.3). FS was performed on surgical specimens from 212 hemipelves; SLNs were identified in 202 specimens (95.7%) and fatty tissue alone was identified in 10 specimens (4.7%). Of the 202 hemipelves in which SLNs were identified, 24 were positive for metastatic disease on final pathology. Initial FS correctly identified only 12, yielding a sensitivity of 50% (12/24, 95% CI 29.6-70.4) and a negative predictive value of 94% (178/190, 95% CI 89-96.5). A total of 24 patients (19%) had LN metastases: 16 (13%) had isolated pelvic metastases, 7 (6%) had both pelvic and para-aortic metastases and 1 (0.8%) had an isolated para-aortic metastasis. CONCLUSIONS: Intraoperative FS of SLNs in high-grade EC patients has poor sensitivity. Since isolated para-aortic metastases are rare, para-aortic lymphadenectomy may be omitted in patients in which SLNs were successfully mapped to the pelvis.

Surgical margin status in relation to surgical approach in the management of early-stage cervical Cancer: A Canadian cervical Cancer collaborative (4C) study.

OBJECTIVE: Surgical margin status in women undergoing surgery for early-stage cervical cancer is an important prognostic factor. We sought to determine whether close (<3 mm) and positive surgical margins are associated with surgical approach and survival. METHODS: This is a national retrospective cohort study of cervical cancer patients treated with radical hysterectomy. Patients with stage IA1/LVSI-Ib2(FIGO 2018) with lesions up to 4 cm at 11 Canadian institutions from 2007 to 2019 were included. Surgical approach included robotic/laparoscopic (LRH), abdominal (ARH) or combined laparoscopic-assisted vaginal/vaginal (LVRH) radical hysterectomy. Recurrence free survival(RFS) and overall survival (OS) were estimated using Kaplan-Meier analysis. Chi-square and log-rank tests were used to compare groups. RESULTS: 956 patients met inclusion criteria. Surgical margins were as follows: negative (87.0%), positive (0.4%) or close <3 mm (6.8%), missing (5.8%). Most patients had squamous histology (46.9%); 34.6% had adenocarcinomas and 11.3% adenosquamous. Most were stage IB (75.1%) and 24.9% were IA. Mode of surgery included: LRH(51.8%), ARH (39.2%), LVRH (8.9%). Predictive factors for close/positive margins included stage, tumour diameter, vaginal involvement and parametrial extension. Surgical approach was not associated with margin status (p = 0.27). Close/positive margins were associated with a higher risk of death on univariate analysis (HR = non calculable for positive and HR = 1.83 for close margins, p = 0.017), but not significant for OS when adjusted for stage, histology, surgical approach and adjuvant treatment. There were 7 recurrences in patients with close margins (10.3%, p = 0.25). 71.5% with positive/close margins received adjuvant treatment. In addition, MIS was associated with a higher risk of death (OR = 2.39, p = 0.029). CONCLUSION: Surgical approach was not associated to close or positive margins. Close surgical margins were associated with a higher risk of death. MIS was associated with worse survival, suggesting that margin status may not be the driver of worse survival in these cases.

Molecular subtype stratified outcomes according to adjuvant therapy in endometrial cancer.

OBJECTIVES: Recent data support the predictive implications of molecular subtype assignment in endometrial cancer (EC). Our objective was to retrospectively assess clinical outcomes according to adjuvant treatment received within EC molecular subtypes. METHODS: Clinical outcomes (disease-specific and progression-free survival DSS/PFS) of EC patients from a single institution and population-based cohorts that had undergone molecular classification were assessed with respect to adjuvant therapy received and 2016 ESMO risk group. RESULTS: 2472 ECs were assessed; 184 (7.4%) POLEmut, 638 (25.8%) MMRd, 1223 (49.5%) NSMP and 427 (17.3%) p53abn. N = 774 (34.6%) of the cohort were ESMO 2016 high risk and 109 (4.8%) were advanced or metastatic. In patients with MMRd EC, assessed across and within stage, there was no observed benefit in DSS or PFS with the addition of chemotherapy +/- radiation compared to radiation alone in ESMO high risk (p = 0.694) or ESMO high, advanced, metastatic risk groups combined (p = 0.852). In patients with p53abn EC, adjuvant chemotherapy given with radiation was associated with significantly longer DSS compared to radiation alone in ESMO high risk (p = 0.007) and ESMO high, advanced and metastatic risk groups combined (p = 0.015), even when restricted to stage I disease (p < 0.001) and when compared in serous vs. non-serous histotypes (p = 0.009). CONCLUSIONS: Adjuvant chemotherapy is associated with more favorable outcomes for patients with p53abn EC, including stage I disease and non-serous histotypes, but does not appear to add benefit within MMRd ECs for any stage of disease, consistent with PORTEC-3 molecular subanalysis. Prospective trials, assessing treatment efficacy within molecular subtype are needed, however these 'real-world' data should be considered when discussing adjuvant treatment with patients.

Evaluating the use of machine learning in endometrial cancer: a systematic review.

OBJECTIVE: To review the literature on machine learning in endometrial cancer, report the most commonly used algorithms, and compare performance with traditional prediction models. METHODS: This is a systematic review of the literature from January 1985 to March 2021 on the use of machine learning in endometrial cancer. An extensive search of electronic databases was conducted. Four independent reviewers screened studies initially by title then full text. Quality was assessed using the MINORS (Methodological Index for Non-Randomized Studies) criteria. P values were derived using the Pearson's Χ2 test in JMP 15.0. RESULTS: Among 4295 articles screened, 30 studies on machine learning in endometrial cancer were included. The most frequent applications were in patient datasets (33.3%, n=10), pre-operative diagnostics (30%, n=9), genomics (23.3%, n=7), and serum biomarkers (13.3%, n=4). The most commonly used models were neural networks (n=10, 33.3%) and support vector machine (n=6, 20%).The number of publications on machine learning in endometrial cancer increased from 1 in 2010 to 29 in 2021.Eight studies compared machine learning with traditional statistics. Among patient dataset studies, two machine learning models (20%) performed similarly to logistic regression (accuracy: 0.85 vs 0.82, p=0.16). Machine learning algorithms performed similarly to detect endometrial cancer based on MRI (accuracy: 0.87 vs 0.82, p=0.24) while outperforming traditional methods in predicting extra-uterine disease in one serum biomarker study (accuracy: 0.81 vs 0.61). For survival outcomes, one study compared machine learning with Kaplan-Meier and reported no difference in concordance index (83.8% vs 83.1%). CONCLUSION: Although machine learning is an innovative and emerging technology, performance is similar to that of traditional regression models in endometrial cancer. More studies are needed to assess its role in endometrial cancer. PROSPERO REGISTRATION NUMBER: CRD42021269565.

Impact of lymphadenectomy and intra-operative tumor rupture on survival in early-stage mucinous ovarian cancers.

OBJECTIVE: Mucinous ovarian carcinoma is a rare subtype of epithelial ovarian cancer with scarce literature guiding its management. We aimed to investigate the optimal surgical management of clinical stage I mucinous ovarian carcinoma by examining the prognostic significance of lymphadenectomy and intra-operative rupture on patient survival. METHODS: We conducted a retrospective cohort study of all pathology-reviewed invasive mucinous ovarian carcinomas diagnosed between 1999 and 2019 at two tertiary care cancer centers. Baseline demographics, surgical management details, and outcomes were collected. Five-year overall survival, recurrence-free survival, and the association of lymphadenectomy and intra-operative rupture on survival were examined. RESULTS: Of 170 women with mucinous ovarian carcinoma, 149 (88%) had clinical stage I disease. Forty-eight (32%; n=149) patients had a pelvic and/or para-aortic lymphadenectomy, but only 1 patient with grade 2 disease was upstaged due to positive pelvic lymph nodes. Intra-operative tumor rupture was documented in 52 cases (35%). On multivariable analysis, after adjusting for age, final stage, and use of adjuvant chemotherapy, there was no significant association between intra-operative rupture with overall survival (HR 2.2 (0.6-8.0); p=0.3) or recurrence-free survival (HR 1.3 (0.5-3.3); p=0.6), or lymphadenectomy with overall survival (HR 0.9 (0.3-2.8); p=0.9) or recurrence-free survival (HR 1.2 (0.5-3.0); p=0.7). Advanced stage was the only factor that was significantly associated with survival. CONCLUSIONS: In clinical stage I mucinous ovarian carcinoma, systematic lymphadenectomy has low utility, as very few patients are upstaged and recurrence typically occurs in the peritoneum. Furthermore, intra-operative rupture does not appear to independently confer a worse survival, and therefore these women may not benefit from adjuvant treatment based on rupture alone.

Role of HPV in the Prediction of Persistence/Recurrence After Treatment for Cervical Precancer.

OBJECTIVES: (1) To determine the role of human papillomavirus (HPV) testing after excisional treatment of cervical precancer. (2) To determine clinical factors associated with persistence of cervical precancer post-treatment. METHODS: A retrospective chart review was conducted including patients who had a loop electrosurgical excision procedure (LEEP) for cervical precancer (cervical intraepithelial neoplasia 3/adenocarcinoma in situ/high-grade squamous intraepithelial lesions [HSIL]). All patients treated between 2016 and 2018 at a tertiary centre colposcopy unit were included. Persistence/recurrence of disease was defined as high-grade cytology or histology identified during the time of follow-up. Univariate and multivariate regression models were performed to identify factors associated with persistence/recurrence and HPV positivity at exit testing. RESULTS: A total of 284 patients were included. The median follow-up time was 19 months. Of the LEEP specimens, 90.8% (n = 258) demonstrated HSIL and 3.9% (n = 11) had adenocarcinoma in situ. 28.5% (n = 81) of the LEEP specimens had positive margins. In follow-up, 72.9% had negative cytology, 17.6% had atypical squamous cells of undetermined significance/low-grade SIL, 1.8% had atypical squamous cells, HSIL cannot be excluded/low-grade SIL-H, and 6.7% had HSIL. At the final follow-up, 27.8% (n = 79) were HPV+. Overall rate of persistence/recurrence was 11.3% (n = 32); median time to persistence/recurrence was 6.5 months. Multivariate regression models demonstrated that follow-up HPV positivity (OR = 22.0) and positive margins (OR = 3.7) were significantly associated with persistence/recurrence. Similarly, in univariate regression models, positive margins were significant (OR = 2.2) for predicting HPV positivity in exit testing. CONCLUSIONS: Persistence/recurrence of precancer can occur due to incomplete treatment of lesions by local excision and by the persistence of HPV infection. Surveillance strategies for women treated for cervical precancer require a risk-based approach and should rely on HPV testing.

Patient-reported outcomes associated with reflex BRCA1/2 tumor and subsequent germline panel genetic testing for high-grade serous ovarian cancer.

Reflex genetic testing of tumor tissue is being completed to direct cancer treatment; however, the patient impact of this genetic testing model is unknown. This survey study evaluates psychological outcomes following tumor and germline genetic testing in individuals with a new diagnosis of high-grade serous ovarian cancer (HGSOC). Individuals were recruited from two hospitals in Toronto, Canada. Participants completed surveys 1 week after receiving tumor results and 1 week after receiving germline results (which included genetic counseling). Outcomes included cancer-related distress (Impact of Events Scale: IES), genetic testing-related distress (Multidimensional Impact of Cancer Risk Assessment: MICRA), and patient satisfaction. Paired t-tests were used to evaluate differences in outcomes following each genetic test result; Cohen's d was used to evaluate effect size. Subgroup analyses were undertaken according to age at diagnosis (<60 years vs. ≥60 years) and test results (any positive vs. both negative). McNemar's test assessed differences in satisfaction. Fifty-two individuals were included in the analyses. Mean IES scores were similar following disclosure of tumor and germline results (27.39 vs. 26.14; p = 0.481; d = 0.101). Compared to following tumor result disclosure, MICRA scores were significantly lower following receipt of germline results with genetic counseling (27.23 vs. 22.69; p = 0.007; d = 0.435). Decreases in MICRA scores from tumor to germline result disclosure were greater for those diagnosed <60 years or those who received only negative test results. Most individuals were satisfied/highly satisfied following tumor (85.7%) and germline (89.8%) results disclosure (p = 0.774). Reflex tumor, and subsequent germline, genetic testing is a new model of care for cancer patients. In our cohort, genetic testing-related distress decreased significantly following receipt of germline results with genetic counseling, especially for individuals diagnosed under 60 years and those receiving only negative results. Most individuals were satisfied with this model of care.

Variability in endometrial carcinoma pathology practice: opportunities for improvement with molecular classification.

We assessed the landscape of diagnostic pathology practice and how molecular classification could potentially impact management of patients with endometrial cancer by collecting patient samples, clinicopathologic data, and patient outcomes from EC patients diagnosed in 2016 at 10 Canadian tertiary cancer centers and 19 community hospitals. ProMisE molecular subtype (POLEmut, MMRd, p53abn, No Specific Molecular Profile (NSMP)) was assigned retrospectively. 1357 patients were fully evaluable including 85 POLEmut (6.3%), 380 MMRd (28.0%), 643 NSMP (47.4%), and 249 p53abn ECs (18.3%). Immunohistochemistry (IHC) for MMR proteins was undertaken at the time of primary diagnosis in 2016 in only 42% of the cohort (570/1357; range 3.5-95.4%/center). p53 IHC had only been performed in 21.1% of the cohort (286/1357; range 10.1-41.9%/center). Thus, based on the retrospective molecular subtype assignment, 54.7% (208/380) of MMRd EC had not been tested with MMR IHC (or MSI) and 48.2% (120/249) of p53abn ECs were not tested with p53 IHC in 2016. Molecular subtype diversity within histotypes was profound; most serous carcinomas were p53abn (91.4%), but only 129/249 (51.8%) p53abn EC were serous. Low-grade (Gr1-2) endometrioid carcinomas were mostly NSMP (589/954, 61.7%) but included all molecular subtypes, including p53abn (19/954, 2.0%). Molecular subtype was significantly associated with clinical outcomes (p < 0.001) even in patients with stage I disease (OS p = 0.006, DSS p < 0.001, PFS p < 0.001). Assessment of national pathologic practice in 2016 shows highly variable use of MMR and p53 IHC and demonstrates significant opportunities to improve and standardize biomarker reporting. Inconsistent, non-reflexive IHC resulted in missed opportunities for Hereditary Cancer Program referral and Lynch Syndrome diagnosis, and missed potential therapeutic implications (e.g., chemotherapy in p53abn EC, immune blockade for MMRd EC). Routine integration of molecular subtyping into practice can improve the consistency of EC pathology assessment and classification.

Pre-operative wait times in high-grade non-endometrioid endometrial cancer: Do surgical delays impact patient survival?

OBJECTIVE: Practice guidelines advocating for regionalization of endometrial cancer surgery to gynecologic oncologists practicing in designated gynecologic oncology centres were published in Ontario in June 2013. Our objectives were to determine whether this policy affected surgical wait times, and whether longer wait time to surgery is a predictor of survival in high grade endometrial cancer patients. METHODS: This was a population-based retrospective cohort study, which included patients diagnosed with high-grade non-endometrioid endometrial cancer who had a hysterectomy between 2003 and 2017. Multivariable Cox proportional hazards regression with a spline function was used to model the relationship between surgical wait time and overall survival (OS). RESULTS: We identified 3518 patients who underwent hysterectomy for high-grade non-endometrioid endometrial cancer. Patients who had surgery with a gynecologic oncologist had a median surgical wait time from diagnosis to hysterectomy of 53 days compared to 57 days pre-regionalization (p = 0.0007), and from first gynecologic oncology consultation to hysterectomy of 29 days compared to 32 days pre-regionalization (p = 0.0006). Survival was inferior for patients who had surgery within 14 days of diagnosis (HR death 2.7 for 1-7 days, 95% CI 1.61-4.51, and HR death 1.96 for 8-14 days, 95% CI 1.50-2.57), reflective of disease severity. Decreased survival occurred with surgical wait times of more than 45 days from the patient's first gynecologic oncology appointment (HR death 1.19 for 46-60 days, 95% CI 1.04-1.36, and HR death 1.42 for 61-75 days, 95% CI 1.11-1.83). CONCLUSIONS: Regionalization of surgery for high-grade endometrial cancer has not had an impact on surgical wait times. Patients who have surgery more than 45 days after surgical consultation have reduced survival.

The accuracy of intraoperative frozen section examination of sentinel lymph nodes in squamous cell cancer of the vulva.

OBJECTIVE: To assess the diagnostic accuracy of intraoperative pathologic examination of sentinel lymph nodes (SLNs) and patient outcomes in vulva cancer. METHODS: This retrospective study included patients with unifocal, <4 cm, invasive vulvar squamous cell carcinoma and clinically negative groin nodes treated with SLN biopsy from January 2008-March 2020. Intraoperative SLN frozen section and final pathology were compared. If the SLN was negative, inguinal femoral lymphadenectomy (IFLD) was omitted. Recurrence location and groin recurrence free survival (RFS) were assessed. RESULTS: The SLN cohort included 173 patients, with 258 groins. On frozen section, there were 36/258 positive and 222 negative groins. On final pathology, there were 39/258 positive: 31 macrometastases, 6 micrometastases, 2 isolated tumor cells (ITCs) and 219 negative groins. The sensitivity, specificity, PPV and NPV for intraoperative detection of metastatic disease, was 89.7% and 99.5%, 97.2% and 98.2%, respectively. There was 1 false positive and 4 false negative frozen section results where final pathology revealed 2 ITCs, 1 micrometastasis and 1 macrometastasis. Based on intraoperative results, thirty patients (17.3%) underwent immediate IFLD. Median follow up was 38.0 (1-137.8) months. The 3-year groin RFS was 91.6% (95% CI 86.2-97.4%) for negative SLNs and 64.6% (95% CI 46.5-89.7%) for positive SLNs on frozen section. Similarly, the 3-year groin RFS was 91.7% (95% CI 86.3-97.4%) for negative, 58.4% (95% CI 38.5-87.7%) for macrometastases and 100% for micrometastases/ITCs on final pathology. CONCLUSIONS: Intraoperative assessment of SLNs is accurate to determine need for IFLD and does not compromise patient outcomes in vulvar cancer.

Comparison of outcomes between abdominal, minimally invasive and combined vaginal-laparoscopic hysterectomy in patients with stage IAI/IA2 cervical cancer: 4C (Canadian Cervical Cancer Collaborative) study.

OBJECTIVE: Although minimally invasive hysterectomy (MIS-H) has been associated with worse survival compared to abdominal hysterectomy (AH) for cervical cancer, only 8% of patients in the LACC trial had microinvasive disease (Stage IA1/IA2). We sought to determine differences in outcome among patients undergoing MIS-H, AH or combined vaginal-laparoscopic hysterectomy (CVLH) for microinvasive cervical cancer. METHODS: A retrospective cohort study of all patients undergoing hysterectomy (radical and non radical) for FIGO 2018, microinvasive cervical cancer across 10 Canadian centers between 2007 and 2019 was performed. Recurrence free survival (RFS) was estimated using Kaplan Meier Survival analysis. Chi-square and log-rank tests were used to compare outcomes. RESULTS: 423 patients with microinvasive cervical cancer were included; 259 (61.2%) Stage IA1 (22/8.5% with LVSI) and 164(38.8%) IA2. The median age was 44 years (range 24-81). The most frequent histology was squamous (59.4%). Surgical approach was: 50.1% MIS-H (robotic or laparoscopic), 35.0% AH and 14.9% CVLH. Overall, 70.9% underwent radical hysterectomy and 76.5% had pelvic lymph node assessment. There were 16 recurrences (MIS-H:4, AH:9, CVLH: 3). No significant difference in 5-year RFS was found (96.7% MIS-H, 93.7% AH, 90.0% CVLH, p = 0.34). In a sub-analysis of patients with IA1 LVSI+/IA2(n = 186), survival results were similar. Further, there was no significant difference in peri-operative complications (p = 0.19). Patients undergoing MIS-H had a shorter median length of stay(0 days vs 3 (AH) vs. 1.5 (CVLH), p < 0.001), but had more ER visits (16.0% vs 3.6% (AH), 3.5% (CVLH), p = 0.036). CONCLUSION: In this cohort, including only patients with microinvasive cervical cancer, no difference in recurrence was found by surgical approach. This may be due to the low rate of recurrence making differences hard to detect or due to a true lack of difference. Hence, this patient population may benefit from MIS without compromising oncologic outcomes.

Variation in practice in endometrial cancer and potential for improved care and equity through molecular classification.

OBJECTIVES: We measured the variation in practice across all aspects of endometrial cancer (EC) management and assessed the potential impact of implementation of molecular classification. METHODS: Centers from across Canada provided representative tumor samples and clinical data, including preoperative workup, operative management, hereditary cancer program (HCP) referrals, adjuvant therapy, surveillance and outcomes, for all EC patients diagnosed in 2016. Tumors were classified into the four ProMisE molecular subtypes. RESULTS: A total of 1336 fully evaluable EC patients were identified from 10 tertiary cancer centers (TC; n = 1022) and 19 community centers (CC; n = 314). Variation of surgical practice across TCs was profound (14-100%) for lymphadenectomy (LND) (mean 57% Gr1/2, 82% Gr3) and omental sampling (20% Gr1/2, 79% Gr3). Preoperative CT scans were inconsistently obtained (mean 32% Gr1/2, 51% Gr3) and use of adjuvant chemo or chemoRT in high risk EC ranged from 0-55% and 64-100%, respectively. Molecular subtyping was performed retrospectively and identified 6% POLEmut, 28% MMRd, 48% NSMP and 18% p53abn ECs, and was significantly associated with survival. Within patients retrospectively diagnosed with MMRd EC only 22% had been referred to HCP. Of patients with p53abn EC, LND and omental sampling was not performed in 21% and 23% respectively, and 41% received no chemotherapy. Comparison of management in 2016 with current 2020 ESGO/ESTRO/ESP guidelines identified at least 26 and 95 patients that would have been directed to less or more adjuvant therapy, respectively (10% of cohort). CONCLUSION: Molecular classification has the potential to mitigate the profound variation in practice demonstrated in current EC care, enabling reproducible risk assessment, guiding treatment and reducing health care disparities.

Predicting recurrence and recurrence-free survival in high-grade endometrial cancer using machine learning.

OBJECTIVE: To develop machine-learning models to predict recurrence and time-to-recurrence in high-grade endometrial cancer (HGEC) following surgery and tailored adjuvant treatment. METHODS: Data were retrospectively collected across eight Canadian centers including 1237 patients. Four models were trained to predict recurrence: random forests, boosted trees, and two neural networks. Receiver operating characteristic curves were used to select the best model based on the highest area under the curve (AUC). For time to recurrence, we compared random forests and Least Absolute Shrinkage and Selection Operator (LASSO) model to Cox proportional hazards. RESULTS: The random forest was the best model to predict recurrence in HGEC; the AUCs were 85.2%, 74.1%, and 71.8% in the training, validation, and test sets, respectively. The top five predictors were: stage, uterus height, specimen weight, adjuvant chemotherapy, and preoperative histology. Performance increased to 77% and 80% when stratified by Stage III and IV, respectively. For time to recurrence, there was no difference between the LASSO and Cox proportional hazards models (c-index 71%). The random forest had a c-index of 60.5%. CONCLUSIONS: A bootstrap random forest model may be a more accurate technique to predict recurrence in HGEC using multiple clinicopathologic factors. For time to recurrence, machine-learning methods performed similarly to the Cox proportional hazards model.

Dual mechanical and pharmacological thromboprophylaxis decreases risk of pulmonary embolus after laparotomy for gynecologic malignancies.

OBJECTIVES: Patients with gynecologic malignancies have high rates of post-operative venous thromboembolism. Currently, there is no consensus for peri-operative thromboprophylaxis specific to gynecologic oncology. We aimed to compare rates of symptomatic pulmonary embolus within 30 days post-operatively, and to identify risk factors for pulmonary embolus. METHODS: The Division of Gynecologic Oncology at Sunnybrook Health Sciences Centre implemented dual thromboprophylaxis for laparotomies in December 2017. We conducted a prospective study of laparotomies for gynecologic malignancies from December 2017 to October 2018, with comparison to historical cohort from January 2016 to November 2017 using the institutional National Surgical Quality Improvement Program database (NSQIP). Pre-intervention, patients received low molecular weight heparin during admission and extended 28-day prophylaxis was continued at the surgeon's discretion. Post-intervention, all patients received both mechanical thromboprophylaxis with sequential compression devices during admission and 28-day prophylaxis with low molecular weight heparin. RESULTS: There were 371 and 163 laparotomies pre- and post-intervention, respectively. Patient characteristics (age, body mass index, diabetes, smoking, tumor stage), rate of malignant cases, operative blood loss and duration, and length of stay were similar between groups. After implementation, pulmonary emboli rates decreased from 5.1% to 0% (p=0.001). There were more cytoreductive procedures pre-intervention (p≤0.0001) but surgical complexity scores were similar (p=0.82). Univariate analysis revealed that surgery pre-intervention (OR 4.25, 95% CI 1.04 to 17.43, p=0.04), length of stay ≥5 days (OR 11.94, 95% CI 2.65 to 53.92, p=0.002), and operative blood loss ≥500 mL (OR 2.85, 95% CI 1.05 to 7.8, p=0.04) increased risk of pulmonary embolus. On multivariable analysis, surgery pre-intervention remained associated with more pulmonary emboli (OR 4.16, 95% CI 1.03 to 16.79, p=0.045), when adjusting for operative blood loss. CONCLUSION: Dual thromboprophylaxis after laparotomy significantly reduced rates of pulmonary embolus in this high-risk patient population.

Brief family history questionnaire to screen for Lynch syndrome in women with newly diagnosed non-serous, non-mucinous ovarian cancers.

OBJECTIVES: While ovarian cancer is the third most common Lynch syndrome-associated cancer in women, there is no established screening strategy to identify Lynch syndrome in this population. The objective of this study was to assess whether the 4-item brief Family History Questionnaire can be used as a screening tool to identify women with ovarian cancer at risk of Lynch syndrome. METHODS: In this prospective cohort study, participants with newly diagnosed non-serous, non-mucinous ovarian cancer completed the brief Family History Questionnaire, extended Family History Questionnaire, and had tumors assessed with immunohistochemistry for mismatch repair proteins, MLH1 methylation, and microsatellite instability testing. All underwent universal germline testing for Lynch syndrome. Performance characteristics were compared between the brief Family History Questionnaire, extended Family History Questionnaire, immunohistochemistry±MLH1 methylation, and microsatellite instability testing. RESULTS: Of 215 participants, 169 (79%) were evaluable with both the brief Family History Questionnaire and germline mutation status; 12 of these 169 were confirmed to have Lynch syndrome (7%). 10 of 12 patients (83%) with Lynch syndrome were correctly identified by the brief Family History Questionnaire, compared with 6 of 11 (55%) by the extended Family History Questionnaire, 11 of 13 (85%) by immunohistochemistry±MLH1 methylation, and 9 of 11 (82%) by microsatellite instability testing. The sensitivity, specificity, positive predictive values, and negative predictive values of the brief Family History Questionnaire were 83%, 65%, 15%, and 98%, respectively. A combined approach with immunohistochemistry and the brief Family History Questionnaire correctly identified all 12 patients with Lynch syndrome. The brief Family History Questionnaire was more sensitive than the extended Family History Questionnaire and took <10 min for each patient to complete. CONCLUSIONS: The brief Family History Questionnaire alone or combined with immunohistochemistry may serve as an adequate screening strategy, especially in centers without access to universal tumor testing.

Reflex BRCA1 and BRCA2 tumour genetic testing for high-grade serous ovarian cancer: streamlined for clinicians but what do patients think?

BACKGROUND: Reflex (automatic) BRCA1 and BRCA2 (BRCA1/2) genetic testing of tumour tissue is being completed for all newly diagnosed high-grade serous ovarian cancer (HGSOC) in the province of Ontario, Canada. The objective of this study was to measure the psychological impact of tumour genetic testing among individuals with a new diagnosis of HGSOC. METHODS: Participants had a new diagnosis of HGSOC and received reflex BRCA1/2 tumour genetic testing as a component of their care. Eligible individuals were recruited from two oncology centres in Toronto, Canada. One week after disclosure of tumour genetic test results, consenting participants were asked to complete a questionnaire that measured cancer-related distress, dispositional optimism, knowledge of hereditary breast/ovarian cancer, recall of tumour genetic test results, satisfaction, and the psychological impact of receiving tumour genetic test results. The Multidimensional Impact of Cancer Risk Assessment (MICRA) questionnaire was used to measure the psychological impact of tumour genetic testing. RESULTS: 76 individuals completed the study survey; 13 said they did not receive their tumour test results. Of the remaining 63 participants, the average MICRA score was 26.8 (SD = 16.3). Higher total MICRA scores were seen among those with children (p = 0.02), who received treatment with primary surgery (p = 0.02), and had higher reported cancer-related distress (p < 0.001). Higher dispositional optimism (p < 0.001) and increasing age (p = 0.03) were associated with lower total MICRA scores. Most (83.5%) participants reported being satisfied/highly satisfied with having tumour testing completed; however, 40.8% could not accurately recall their tumor test results. CONCLUSIONS: This study is the first to assess psychological outcomes following reflex BRCA1/2 tumour genetic testing in women newly diagnosed with HGSOC. Increased dispositional optimism provided a protective effect, while increased cancer-related distress increased the psychological impact of tumour genetic testing. Educational resources are needed to help increase patient understanding and recall of tumour results, particularly when tumour genetic testing includes analysis of genes that may have implications for hereditary cancer risk. Additional research is required to better understand the patient experience of reflex tumour genetic testing.