Quantification of impact of COVID-19 pandemic on cancer screening programmes – a case study from Argentina, Bangladesh, Colombia, Morocco, Sri Lanka, and Thailand

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    This study provides important estimates from international cancer screening data repository about the impact of the COVID-pandemic related disruptions on cancer screening programs in selected low- and middle-income countries. The evidence supporting the study is solid and relies on national-level screening program attendee volumes and assessments of screen positives during 2019 (pre-pandemic) and 2020 (during the pandemic). The study provides real-world data estimates of proportions/volumes of missed screenings due to pandemic control measures (lockdowns and closures) and may contribute to future modelling efforts for measuring the impact on late/advanced stage detection and excess case burden and mortality.

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Abstract

It is quite well documented that the COVID-19 pandemic disrupted cancer screening services in all countries, irrespective of their resources and healthcare settings. While quantitative estimates on reduction in volume of screening tests or diagnostic evaluation are readily available from the high-income countries, very little data are available from the low- and middle-income countries (LMICs). From the CanScreen5 global cancer screening data repository we identified six LMICs through purposive sampling based on the availability of cancer screening data at least for the years 2019 and 2020. These countries represented those in high human development index (HDI) categories (Argentina, Colombia, Sri Lanka, and Thailand) and medium HDI categories (Bangladesh and Morocco). No data were available from low HDI countries to perform similar analysis. The reduction in the volume of tests in 2020 compared to the previous year ranged from 14.1% in Bangladesh to 72.9% in Argentina (regional programme) for cervical screening, from 14.2% in Bangladesh to 49.4% in Morocco for breast cancer screening and 30.7% in Thailand for colorectal cancer screening. Number of colposcopies was reduced in 2020 compared to previous year by 88.9% in Argentina, 38.2% in Colombia, 27.4% in Bangladesh, and 52.2% in Morocco. The reduction in detection rates of CIN 2 or worse lesions ranged from 20.7% in Morocco to 45.4% in Argentina. Reduction of breast cancer detection by 19.1% was reported from Morocco. No association of the impact of pandemic could be seen with HDI categories. Quantifying the impact of service disruptions in screening and diagnostic tests will allow the programmes to strategize how to ramp up services to clear the backlogs in screening and more crucially in further evaluation of screen positives. The data can be used to estimate the impact on stage distribution and avoidable mortality from these common cancers.

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  1. eLife assessment

    This study provides important estimates from international cancer screening data repository about the impact of the COVID-pandemic related disruptions on cancer screening programs in selected low- and middle-income countries. The evidence supporting the study is solid and relies on national-level screening program attendee volumes and assessments of screen positives during 2019 (pre-pandemic) and 2020 (during the pandemic). The study provides real-world data estimates of proportions/volumes of missed screenings due to pandemic control measures (lockdowns and closures) and may contribute to future modelling efforts for measuring the impact on late/advanced stage detection and excess case burden and mortality.

  2. Reviewer #1 (Public Review):

    The impact of the COVID-19 pandemic on cancer screening, diagnosis, referrals, and management has been well documented in high-resourced countries; but such quantitative estimates are rarely available from low- and middle-income countries (LMIC). The authors chose two very high human development index (HDI) category LMICs (Argentina and Thailand), two high HDI category LMICs (Colombia and Sri Lanka), and two medium HDI category LMICs (Bangladesh and Morocco), and looked at available data for cervical, breast, and colorectal cancer screening. The authors demonstrate that the reduction in the test volumes during the pandemic (2020) versus the previous year (2019) was quite comparable to that observed in high-income countries. Additionally, some countries demonstrated resilient catch-up of programmatic performance within a short period of time after the disruptions.

    Major strengths include the use of national-level data estimates from key focal points for the CancScreen-5 project, an international data repository of cancer screening programmatic data, the use of appropriately comparable monthly estimates in the pre-pandemic vs. pandemic year, and representation of illustrative case studies from six countries across the medium-to-very high HDI status among LMICs.

    Weaknesses include inherent limitations of such real-world outcome/registry data, lack of data across the screening continuum, inability to explore granular-level country-specific factors affecting disruptions as well as catch-up of screening, and high variability of performance of screening tests (especially those with subjective interpretation such as VIA for cervical cancer or clinical breast exam) across the comparison periods such that screen positivity rates may have been affected in unpredictable ways.

    The authors have achieved their aims since this descriptive epidemiology analysis provides key estimates from LMICs that have not been explored/evaluated in the literature.

    This work will be useful for future studies conducted by health modellers on measuring the impact on late/advanced stage detection and excess case burden and mortality.

  3. Reviewer #2 (Public Review):

    The Covid-19 pandemic has had major adverse impacts on cancer screening globally. Despite this, most prior reports have not included observations from LMICs. This paper aims to address this important gap.

    Because comparable data were not available across the countries reported here, comparisons would not be appropriate, so the authors chose a case study design, which was a prudent decision and a strength of the work.

    The authors make use of data from IARC's CanScreen5 reporting system, which is completely appropriate. In addition, this aspect serves to demonstrate the usefulness of the CanScreen5 system, as it can be used to support this type of study. National data were not available in all countries.

    The main findings in the paper describe the early impact of the Covid-19 pandemic on cancer screening participation for the screening programs reported on in the 6 countries that were selected.

    I would anticipate that, having demonstrated that this type of case study focusing on cancer screening in LMICs is feasible, this would encourage others to conduct further studies among LMICs, which would be welcomed by the field.

  4. Reviewer #3 (Public Review):

    International researchers from the International Agency for Research on Cancer and cancer screening program experts from six countries in Latina America (Argentina, Colombia), Asia (Sri Lanka, Bangladesh, Thailand), and Northern Africa (Morocco), provide detailed information on the impact of the COVID Pandemic on cancer screening and diagnostic services.

    The authors examine countries that have had screening programs and a surveillance system/registry to see how the volume of screening, diagnostic procedures, and detection of precancers or cancers are impacted. The data are presented as case studies with an explanation of the program, the technologies, and then the impact. They describe no matter how low or high income the country, there was a considerable impact on the volume of screening.

    Usually, the impact of the pandemic on cancer screening has been limited to Europe or North America and is usually not quantified. This information will be helpful for these countries to examine the impact on stage distribution and eventually mortality impact through modeling studies. The authors also comment on some interesting hypotheses such that the impact on recovery based on if one is detecting precancers (e.g. colon cancer/cervical cancer) vs. invasive cancers (breast cancer). Strategies that require less frequent screening,self-collection, where screening and treatment can be combined in fewer visits, or where some visits can occur via telehealth are valuable strategies or lessons learned that will allow for quicker recovery time after a pandemic.

    The authors acknowledge the limitations and strengths of these case-based studies well.

    It is beautiful storytelling with both qualitative and quantitative data.