Anecdotal reports of more extensive staging at cancer diagnosis cannot be confirmed using Antwerp Network Hospital data

May 2022 Covid-19 Dominique Vrouwenvelder

The COVID-19 pandemic had a huge impact on the Belgian healthcare system in March and April 2020. All non-urgent procedures and examinations were postponed and screening programs were suspended. It was anticipated that this would lead to a delay in cancer diagnoses.

As of March 14, 2020, a ministerial decree postponed all non-urgent consultations, procedures and examinations. Urgent and necessary care could continue, such as dialysis and chemotherapy. Screening programs were paused during March, April and May.

Many patients postponed a visit to the general practitioner because of Covid measures, but also because of fear of the virus. Some feared that this would delay the diagnosis of cancer, and in August 2020 the first reports of more advanced cancer diagnoses surfaced in the popular media.

Study details

This article by Sacha Mignon et al. examines the impact of the Covid-19 epidemic on the proportion of diagnoses of metastatic disease in the most frequent cancers, being invasive breast, colorectal, lung and prostate cancer. Only distant metastases were considered metastatic disease.

This study examined whether the stage at diagnosis of the most common cancers between March 1st, 2020 and August 31, 2020 was different compared to the same period in 2018 and 2019 at the Antwerp Network Hospital (‘Ziekenhuis Netwerk Antwerpen’, ZNA), based on the cancer registry of the hospital.

Results

From March to August 2018, 2019 and 2020, 471, 454 and 405 patients were diagnosed with the studied cancers, respectively. The number and metastatic status of breast cancer, colorectal cancer, lung cancer, and prostate cancer can be found in Table 1.

Tumour type201820192020p-value
Breast961171040,34
– non-metastatic9010887
– metastatic5710
– unknown metastatic status127
Colorectal10578780,48
– non metastatic816251
– metastatic201619
– unknown metastatic status408
Lung1411261200,26
– non-metastatic626549
– metastatic756170
– unknown metastatic status401
Prostate1291331030.13
– non-metastatic11410884
– metastatic122413
– unknown metastatic status316
Table 1: diagnosis of invasive cancers in the observation period March to August for 2018, 2019 and 2020. Adapted from TvGG.

In 2020, there was a reduction in the total number of diagnoses of breast, lung and prostate cancer compared to 2019. This reduction was most pronounced in prostate cancer with a relative reduction of 23% compared to 2019. The relative reduction in the number of breast and lung cancer diagnoses was less pronounced: 11% and 5%, respectively.

The authors found no association between the time of diagnosis and the extensiveness of the disease. Although the different diagnoses occurred at similar proportions – and thus there were no more diagnoses of metastatic disease than before – the total number of diagnoses of invasive disease for breast, prostate, and lung cancer did decrease compared to the same period in 2019. The reduction was most pronounced for prostate cancer with a relative reduction of 23%.

Implications

It is feared that the reduction in cancer diagnoses will result in an increase in the number of diagnoses once the epidemic is over. The health effects of delayed diagnosis are likely to correlate strongly with the aggressiveness of the cancer type. For this reason, the greater reduction in prostate cancer diagnoses, generally a less aggressive tumor, could have less significant consequences than the more limited reduction in breast and lung cancer diagnoses.

Conclusion

Anecdotal reports of more extensive staging at diagnosis cannot be confirmed with the ZNA cancer registry within the six-month observation period after lockdown. To date, the restriction measures for Covid-19 do not seem to have a major impact on the proportion of diagnoses of metastatic cancer in the time period studied in ZNA. Further research should show whether the decrease in the numerical number of registrations will translate into more late diagnoses in the long run.

Reference

Mignon S, Vervoort C, Van de Velde S, et al. De impact van de Covid-19-epidemie op het aandeel diagnoses van metastatische ziekte van de meest frequente kankers. TvGG. 2021, volume 4.

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