Pan-Canadian survey on the impact of the COVID-19 pandemic on cervical cancer screening and management (preprint)

Background: The COVID-19 pandemic has caused disruptions to cancer care by delaying diagnoses and treatment, presenting challenges and uncertainties for both patients and physicians. We conducted a nationwide online survey to investigate the effects of the pandemic and capture modifications, prompted by pandemic-related control measures, on cervical cancer screening-related activities from mid-March to mid-August 2020, across Canada. Methods: The survey consisted of 61 questions related to the continuum of care in cervical cancer screening and treatment: appointment scheduling, tests, colposcopy, follow-up, treatment of pre-cancerous lesions/cancer, and telemedicine. We piloted the survey with 21 Canadian experts in cervical cancer prevention and care. We partnered with the Society of Canadian Colposcopists, Society of Gynecologic Oncology of Canada, Canadian Association of Pathologists, and Society of Obstetricians and Gynecologists of Canada, which distributed the survey to their members via email. We reached out to family physicians and nurse practitioners via MDBriefCase. The survey was also posted on McGill Channels (Department of Family Medicine News and Events) and social media platforms. The data were analyzed descriptively. Results: Unique responses were collected from 510 participants (16 November 2020 - 28 February 2021), representing 418 fully- and 92 partially- completed surveys. Responses were from Ontario (41.0%), British Columbia (21.0%), and Alberta (12.8%), and mostly comprised family physicians/general practitioners (43.7%), and gynecologist/obstetrician professionals (21.6%). Cancelled screening appointments were mainly reported by family physicians/general practitioners (28.3%), followed by gynecologist/obstetrician professionals (19.8%), and primarily occurred in private clinics (30.5%). Decreases in the number of screening Pap tests and colposcopy procedures were consistently observed across Canadian provinces. About 90% reported that their practice/institution adopted telemedicine to communicate with patients. Conclusions: The area most severely impacted by the pandemic was appointment scheduling, with an important level of cancellations reported. Survey results may inform resumptions of various fronts in cervical cancer screening and management.

The impact of lag time to cancer diagnosis and treatment on clinical outcomes prior to the COVID-19 pandemic: a scoping review of systematic reviews and meta-analyses (preprint)

Background: The COVID-19 pandemic has disrupted cancer care, raising concerns regarding the impact of wait time, or lag time, on clinical outcomes. We aimed to contextualize pandemic-related lag times by mapping pre-pandemic evidence from systematic reviews and/or meta-analyses on the association between lag time to cancer diagnosis and treatment with mortality- and morbidity-related outcomes. Methods: We systematically searched MEDLINE, EMBASE, Web of Science, and Cochrane Library of Systematic Reviews for reviews published prior to the pandemic (1 January 2010-31 December 2019). We extracted data on methodological characteristics, lag time interval start and endpoints, qualitative findings from systematic reviews, and pooled risk estimates of mortality- (i.e., overall survival) and morbidity- (i.e., local regional control) related outcomes from meta-analyses. We categorized lag times according to milestones across the cancer care continuum and summarized outcomes by cancer site and lag time interval. Results: We identified 9,032 records through database searches, of which 29 were eligible. We classified 33 unique types of lag time intervals across 10 cancer sites, of which breast, colorectal, head and neck, and ovarian cancers were investigated most. Two systematic reviews investigating lag time to diagnosis reported contradictory findings regarding survival outcomes among pediatric patients with Ewing's sarcomas or central nervous system tumours. Comparable risk estimates of mortality were found for lag time intervals from surgery to adjuvant chemotherapy for breast, colorectal, and ovarian cancers. Risk estimates of pathologic complete response indicated an optimal time window of 7-8 weeks for neoadjuvant chemotherapy completion prior to surgery for rectal cancers. In comparing methods across meta-analyses on the same cancer sites, lag times, and outcomes, we identified critical variations in lag time research design. Conclusions: Our review highlighted measured associations between lag time and cancer-related outcomes and identified the need for a standardized methodological approach in areas such as lag time definitions and accounting for the waiting-time paradox. Prioritization of lag time research is integral for revised cancer care guidelines under pandemic contingency and assessing the pandemic's long-term effect on patients with cancer.

Predicted long-term impact of COVID-19 pandemic-related care delays on cancer incidence and mortality in Canada (preprint)

ObjectivesThe COVID-19 pandemic has affected cancer care worldwide. This study aimed to estimate the long-term impacts of the pandemic on cancer incidence and mortality in Canada using a mathematical model. MethodsWe developed a stochastic microsimulation model to estimate the cancer care disruptions and its long-term impact on cancer incidence and mortality in Canada. The model reproduces cancer incidence, survival, and epidemiology in Canada, by using cancer incidence, stage at diagnosis and survival data from the Canadian Cancer Registries. We modeled reported declines in cancer diagnoses and treatments recorded in provincial administrative datasets from March 2020-June 2021. We assumed that diagnostic and treatment delays lead to an increased rate of death. Based on the literature, we assumed each 4-week delay in diagnosis and treatment would lead to a 6% to 50% higher rate of cancer death. Results are the median predictions of 10 stochastic simulations. FindingsThe model predicts that cancer care disruptions during the COVID-19 pandemic could lead to 21,247 (2{middle dot}0%) more cancer deaths in Canada in 2020-2030, assuming treatment capacity is recovered to 2019 pre-pandemic levels in 2021. This represents 355,172 life years lost expected due to pandemic-related diagnostic and treatment delays. The highest absolute expected excess cancer mortality was predicted in breast, lung, and colorectal cancers, and in the provinces of Ontario, Quebec, and British Columbia. Diagnostic and treatment capacity in 2021 onwards highly influenced the number of predicted cancer deaths over the next decade. InterpretationCancer care disruptions during the Covid-19 pandemic could lead to significant life loss; however, most of these could be mitigated by increasing diagnostic and treatment capacity in the post-pandemic era to address the service backlog. FundingCanadian Institutes of Health Research Research in contextO_ST_ABSEvidence before this studyC_ST_ABSWe performed a review of modeling studies predicting the impact of pandemic-induced disruptions to cancer care on cancer survival outcomes. We searched MEDLINE on 2 July 2021 for records published from 1 January 2020 with no language restrictions. Our search consisted of index keywords [Cancer AND COVID-19 AND [(delay AND diagnosis) OR (delay AND screening) OR (delay AND treatment)] AND outcomes AND modelling study]. We identified 14 studies that model the long-term effect of disruptions to cancer screening programs, diagnostic intervals, and to treatment intervals for common cancers. Most studies (9/14) assessed the impact of cancer screening disruptions but did not assume any treatment disruptions. Disruptions to cancer screening services in high income health systems were estimated to lead to small increases in cancer incidence and mortality, even with immediate resumption of screening to services after disruption periods. Fewer studies examined the impact of diagnostic referral and treatment disruptions; these are similarly predicted to lead to increases in cancer incidence and mortality, with varying impacts depending on cancer site. Due to difficulties in obtaining real-time healthcare data, previous studies have relied on assumptions regarding the duration of health care disruptions (1-, 3-, 6-, 12-, to 24-months) rather than on empirical data. All studies restricted their analysis to the impact on a single or a few cancer sites. Added value of this studyOur stochastic microsimulation model is the first to assess the population-level impact of diagnostic and treatment disruptions on overall cancer mortality across all sites. Using Canadian cancer statistics and expert validation of treatment modalities, we constructed a model that reproduced pre-pandemic cancer mortality data. An important added value of this analysis compared to previous studies was that we were able to integrate empirical data on cancer-related procedures during the pandemic era to model disruptions to cancer care. Implications of all the available evidenceWe estimate there could be a 2{middle dot}0% increase over expected cancer mortality between 2020-2030 in Canada due to pandemic-related disruptions to diagnostic and treatment intervals. Our results identified that a 10-20% increase in cancer care service capacity over pre-pandemic levels could prevent a considerable amount of the predicted excess cancer-related deaths by reducing diagnostic and treatment backlogs. By stratifying our reported outcomes by sex, age, province, and cancer site, we provide a long-term perspective that can inform post-pandemic public health policy or aid in prioritization of patients in the event of a resurgence of COVID-19. While our model is specific to Canada, it could be applied to countries that have experienced comparable COVID-19-related healthcare disruptions.