Stuart Peacock

Real-World Safety of Niraparib for Maintenance Treatment of Ovarian Cancer in Canada

Niraparib was recently funded in Canada for the maintenance treatment of ovarian cancer following platinum-based chemotherapy. However, the drug’s safety profile in the real world remains uncertain. We conducted a cohort study to describe the patient population using niraparib and the proportion that experienced adverse events between June 2019 and December 2022 in four Canadian provinces (Ontario, Alberta, British Columbia [BC], and Quebec). We used administrative data and electronic medical records from Ontario Health, Alberta Health Services, and BC Cancer, and registry data from Exactis Innovation. We summarized baseline characteristics using descriptive statistics and reported safety outcomes using cumulative incidence. We identified 514 patients receiving niraparib. Mean age was 67 years and most were initiated on a daily dose of 100 or 200 mg/day. Grade 3/4 anemia, neutropenia, and thrombocytopenia occurred in 11–16% of the cohort. In Ontario, the three-month cumulative incidence of grade 3/4 thrombocytopenia was 11.6% (95% CI, 8.3–15.4%), neutropenia was 7.1% (95% CI, 4.6–10.4%), and anemia was 11.3% (95% CI, 8.0–15.2%). Cumulative incidences in the remaining provinces were similar. Initial daily dose and proportions of hematological adverse events were low in the real world and may be related to cautious prescribing and close monitoring by clinicians.

Cervical Cancer Screening Cascade: A Framework for Monitoring Uptake and Retention Along the Screening and Treatment Pathway

Background: Cervical cancer is a major global health concern, causing approximately 350,000 deaths annually. It is also preventable through effective prevention and early detection. To facilitate elimination, the World Health Organization (WHO) set targets for HPV vaccination, screening, and treatment. Achieving these goals requires frameworks to monitor screening program performance. As many regions transition to HPV primary screening, a standardized Cervical Cancer Screening Cascade can track performance, identify gaps in follow-up, and optimize resource allocation. Methods: This paper introduces a structured cascade developed to monitor uptake, retention, and outcomes in HPV-based screening programs. The Cascade was created through collaboration between public health experts, clinicians, and researchers at the University of British Columbia (UBC), the Women’s Health Research Institute, and BC Cancer. Results: The Cascade outlines four phases: screening, triage, detection, and treatment. Each phase includes two substages: “uptake” and “results,” with an additional substage in screening (“invitation”). “Screening” assesses invitation effectiveness and participation. “Triage” tracks follow-up after a positive screen. “Detection” evaluates attendance at diagnostic appointments, and “Treatment” measures the treatment rate for those with precancerous lesions. Conclusions: The Cascade can guide emerging and existing HPV screening programs within Canada and other similarly resourced settings and serve as a benchmark tool for programs to assess their progress towards cervical cancer elimination.

Assessing 10-Year Safety of a Single Negative HPV Test for Cervical Cancer Screening: Evidence from FOCAL-DECADE Cohort

Abstract Background: Long-term safety of a single negative human papillomavirus (HPV) test for cervical cancer screening is unclear. The HPV FOr cerviCAL Cancer Trial (FOCAL) was a randomized trial comparing HPV testing with cytology. The FOCAL-DECADE cohort tracked women who received one HPV test during FOCAL, and were HPV negative, for up to 10 years to identify cervical intraepithelial neoplasia grade 2 or worse (CIN2+) and grade 3 or worse (CIN3+) detected through a provincial screening program. Methods: FOCAL participants who received one HPV test, were negative, and had at least one post-FOCAL cervix screen were included (N = 5,537). We constructed cumulative incidence curves of CIN2+/CIN3+ detection, analyzed cumulative risk of detection at intervals post-HPV test, calculated average incidence rates for detection, and compared hazard across ages. Results: Ten years after one negative HPV test, the probability of CIN2+ detection was lower than 1%, with most lesions detected 7 years or later. Average incidence rates of CIN2+/CIN3+ lesions over follow-up were 0.50 [95% confidence interval (CI), 0.31–0.78] and 0.18 (95% CI, 0.07–0.36) per 1,000 person-years, respectively. Hazards were higher for younger ages (nonsignificant trend). Conclusions: Among women with a single negative HPV test, long-term risk of CIN2+ detection was low, particularly through 7 years of follow-up; thus, one negative HPV test appears to confer long-term protection from precancerous lesions. Even 10-year risk is sufficiently low to support extended testing intervals in average-risk populations. Impact: Our findings support the safety of screening policies using HPV testing alone at 5-year or longer intervals.

Cost‐effectiveness analysis of primary human papillomavirus testing in cervical cancer screening: Results from the HPV FOCAL Trial

AbstractThe Human Papillomavirus FOr CervicAL cancer (HPV FOCAL) trial is a large randomized controlled trial comparing the efficacy of primary HPV testing to cytology among women in the population‐based Cervix Screening Program in British Columbia, Canada. We conducted a cost‐effectiveness analysis based on the HPV FOCAL trial to estimate the incremental cost per detected high‐grade cervical intraepithelial neoplasia of grade 2 or worse lesions (CIN2+). A total of 19,009 women aged 25 to 65 were randomized to one of two study groups. Women in the intervention group received primary HPV testing with reflex liquid‐based cytology (LBC) upon a positive finding with a screening interval of 48 months. Women in the control group received primary LBC testing, and those negative returned at 24 months for LBC and again at 48 months for exit screening. Both groups received HPV and LBC co‐testing at the 48‐month exit. Incremental costs during the course of the trial were comparable between the intervention and control groups. The intervention group had lower overall costs and detected a larger number of CIN2+ lesions, resulting in a lower mean cost per CIN2+ detected ($7551) than the control group ($8325), a difference of ‐$773 [all costs in 2018 USD]. Cost per detected lesion was sensitive to the costs of sample collection, HPV testing, and LBC testing. The HPV FOCAL Trial results suggest that primary HPV testing every 4 years produces similar outcomes to LBC‐based testing every 2 years for cervical cancer screening at a lower cost.

Willingness to Self-Collect a Sample for HPV-Based Cervical Cancer Screening in a Well-Screened Cohort: HPV FOCAL Survey Results

Self-collection may provide an opportunity for innovation within population-based human papillomavirus (HPV) cervical cancer screening programs by providing an alternative form of engagement for all individuals. The primary objective was to determine willingness to self-collect a vaginal sample for primary HPV screening and factors that impact willingness in individuals who participated in the Human Papillomavirus For Cervical Cancer (HPV FOCAL) screening trial, a large randomized controlled cervical screening trial. A cross-sectional online survey was distributed between 2017 and 2018 to 13,176 eligible participants exiting the FOCAL trial. Bivariate and multivariable logistic regression assessed factors that influence willingness to self-collect on 4945 respondents. Overall, 52.1% of respondents indicated willingness to self-collect an HPV sample. In multivariable analysis, the odds of willingness to self-collect were significantly higher in participants who agreed that screening with an HPV test instead of a Pap test was acceptable to them (odds ratio (OR): 1.45 (95% confidence interval (CI): 1.15, 1.82), those who indicated that collecting their own HPV sample was acceptable to them (p < 0.001), and those with higher educational ascertainment (OR: 1.31, 95% CI: 1.12, 1.54). The findings offer insight into the intentions to self-collect in those already engaged in screening, and can inform cervical cancer screening programs interested in offering alternative approaches to HPV-based screening.

Human papillomavirus‐based screening at extended intervals missed fewer cervical precancers than cytology in the HPV For Cervical Cancer (HPV FOCAL) trial

AbstractWhile cervix screening using cytology is recommended at 2‐ to 3‐year intervals, given the increased sensitivity of human papillomavirus (HPV)‐based screening to detect precancer, HPV‐based screening is recommended every 4‐ to 5‐years. As organized cervix screening programs transition from cytology to HPV‐based screening with extended intervals, there is some concern that cancers will be missed between screens. Participants in HPV FOr CervicAL Cancer (HPV FOCAL) trial received cytology (Cytology Arm) at 24‐month intervals or HPV‐based screening (HPV Arm) at 48‐month intervals; both arms received co‐testing (cytology and HPV testing) at exit. We investigated the results of the co‐test to identify participants with cervical intraepithelial neoplasia grade 2 or higher (CIN2+) who would not have had their precancer detected if they had only their arm's respective primary screen. In the Cytology Arm, 25/62 (40.3%) identified CIN2+s were missed by primary screen (ie, normal cytology/positive HPV test) and all 25 had normal cytology at the prior 24‐month screen. In the HPV arm, three CIN2+s (3/49, 6.1%) were missed by primary screen (ie, negative HPV test/abnormal cytology). One of these three misses had low‐grade cytology findings and would also not have been referred to colposcopy outside of the trial. Multiple rounds of cytology did not detect some precancerous lesions detected with one round of HPV‐based screening. In our population, cytology missed more CIN2+, even at shorter screening intervals, than HPV‐based screening. This assuages concerns about missed detection postimplementation of an extended interval HPV‐based screening program. We recommend that policymakers consider a shift from cytology to HPV‐based cervix screening.

Evidence of Decreased Long-term Risk of Cervical Precancer after Negative Primary HPV Screens Compared with Negative Cytology Screens in a Longitudinal Cohort Study

Abstract Background: The growing use of primary human papillomavirus (HPV) cervical cancer screening requires determining appropriate screening intervals to avoid overtreatment of transient disease. This study examined the long-term risk of cervical precancer after HPV screening to inform screening interval recommendations. Methods: This longitudinal cohort study (British Columbia, Canada, 2008 to 2022) recruited women and individuals with a cervix who received 1 to 2 negative HPV screens (HPV1 cohort, N = 5,546; HPV2 cohort, N = 6,624) during a randomized trial and women and individuals with a cervix with 1 to 2 normal cytology results (BCS1 cohort, N = 782,297; BCS2 cohort, N = 673,778) extracted from the provincial screening registry. All participants were followed through the registry for 14 years. Long-term risk of cervical precancer or worse [cervical intraepithelial neoplasia grade 2 or worse (CIN2+)] was compared between HPV and cytology cohorts. Results: Cumulative risks of CIN2+ were 3.2/1,000 [95% confidence interval (CI), 1.6–4.7] in HPV1 and 2.7/1,000 (95% CI, 1.2–4.2) in HPV2 after 8 years. This was comparable with the risk in the cytology cohorts after 3 years [BCS1: 3.3/1,000 (95% CI, 3.1–3.4); BCS2: 2.5/1,000 (95% CI, 2.4–2.6)]. The cumulative risk of CIN2+ after 10 years was low in the HPV cohorts [HPV1: 4.7/1,000 (95% CI, 2.6–6.7); HPV2: 3.9 (95% CI, 1.1–6.6)]. Conclusions: Risk of CIN2+ 8 years after a negative screen in the HPV cohorts was comparable with risk after 3 years in the cytology cohorts (the benchmark for acceptable risk). Impact: These findings suggest that primary HPV screening intervals could be extended beyond the current 5-year recommendation, potentially reducing barriers to screening.