ArticleCancer medicine2023
Evaluating the impact of COVID-19 on cancer declarations in Quebec, Canada.
Article in Cancer medicine, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers, 1 of them a synthesis that pooled it.
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Who cites it
15 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Impact of the Sars-Cov-2 outbreak on the initial clinical presentation of new solid cancer diagnoses: a systematic review and meta-analysis.BMC cancer · 2024Pooled it
- Impact of the COVID-19 Pandemic on Lung Cancer Screening and Diagnosis: A Systematic Review.Cancers · 2026Review
- Colorectal cancer incidence before and during the COVID-19 pandemic: a non-linear interrupted time-series analysis.Scientific reports · 2026Article
- Impact of the COVID-19 Pandemic on Gut Cancer Admissions and Management: A Comparative Study of Two Pandemic Years to a Similar Pre-Pandemic Period.Healthcare (Basel, Switzerland) · 2025Article
- Effects of the COVID-19 pandemic on surgical treatment for thoracic malignant tumor cases in Japan: a national clinical database analysis.Surgery today · 2025Article
- Exploring health related quality of life for women with breast cancer in Ireland and Québec, Canada throughout the COVID-19 pandemic.Scientific reports · 2025Article
- Changes in female cancer diagnostic billing rates over the COVID-19 period in the Ontario Health Insurance Plan.Therapeutic advances in medical oncology · 2025Article
- Effect of the COVID-19 Pandemic on the Management of Breast Cancer Patients.Journal of clinical medicine · 2024Article
- The impact of the COVID-19 pandemic on symptomatic breast cancer presentations in an Irish breast cancer unit: a retrospective cohort study.Irish journal of medical science · 2024Article
- Improving Care for Older Adults with Cancer in Canada: A Call to Action.Current oncology (Toronto, Ont.) · 2024Review
- Resource allocation during the coronavirus disease 2019 pandemic and the impact on patients with lung cancer: a systematic review.Interdisciplinary cardiovascular and thoracic surgery · 2023Article
- Addressing the ethical problem of underdiagnosis in the post-pandemic Canadian healthcare system.Healthcare management forum · 2023Article
- Impact of the COVID-19 pandemic on clinical presentation, treatments, and outcomes of new breast cancer patients: A retrospective multicenter cohort study.Cancer medicine · 2023Article
- Impact of the COVID-19 pandemic on cancer diagnoses, stage and survival in Alberta.CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 2023Article
- Evaluating the impact of COVID-19 on cancer declarations in Quebec, Canada.Cancer medicine · 2023Article
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6 authors.
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Abstract
backgroundCOVID-19 affected healthcare worldwide, limited access to healthcare, and delayed cancer screening and diagnosis. In this study, the effect of the first year of COVID-19 was determined on cancer diagnoses in the province of Quebec, Canada.
methodsData were collected from the 13 Quebec Cancer Registry health institutions. Newly diagnosed cancer declarations in the first year of the COVID-19 (April 2020-March 2021) were compared with the reference periods (averages of 3 previous years). The main focus was on four leading cancers: lung, prostate, colorectal, and breast cancers. Generalized regression models with a poisson approximation and interrupted time series (ITS) analysis were used. Underestimated cases were presented in terms of relative risk (RR) and 95% confidence intervals (CI). The changes in the stage-specific counts were also assessed in each of the four cancers. Results were illustrated separately for the first 4 months of the pandemic (first wave).
findingsThis study estimated an overall under-reporting of 15.3% (29,019 vs. 24,584) of declarations. This under-reporting was evident across all age groups above 35 years (p < 0.0001), four primary cancers (p < 0.0001), all stages of cancers (p < 0.0001), and both sexes (p < 0.0001). Based on the relative risks, stage-specific lung cancer counts were underestimated by 5%-34% in the first wave (0%-11% in the first year), prostate cancer by 16%-46% in the first wave (0%-25% in the first year), colorectal cancer 15%-45% in the first wave (0%-24% in the first year), and breast cancer 3%-45% in the first wave and (0%-28% in the first year). However, no stage-IV cancers were statically under-reported compared to the pre-pandemic era and not even in the first wave.
interpretationCancer diagnosis was underestimated due to the COVID-19 pandemic in the first year; this effect was more evident in the first phase of the pandemic in Quebec. Further research is required to determine the accurate burden of the disease in the long term.
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