Impact of the COVID-19 pandemic in colorectal cancer diagnosis and presentation

Impact of the COVID-19 pandemic on cancer screenings in Portugal

OBJECTIVES

This study aimed to evaluate the impact of the COVID-19 pandemic on cancer screening in Portugal, and its consequences on cancer morbidity and mortality.

METHODS

The pre-pandemic and pandemic periods were compared using publicly available data on performance and health outcomes indicators of the Portuguese NHS, namely the numbers and proportions of eligible individuals who underwent cancer screening (breast, cervical or colorectal). Pre-pandemic data were modelled to project hypothetical scenarios without a pandemic using an exponential smoothing algorithm, and then compared with data collected during the COVID-19 pandemic. A Markov model was developed to estimate years of life lost (YLL) due the reduction in the number of cancer screenings during the pandemic. The MS Excel and the PRISM symbolic model checker software were used.

RESULTS

There was a decrease in the number of breast (13 %), cervical (15 %) and colorectal (9-11 %) cancers screenings during the first two years of the pandemic. The model projections are 506, 41, and 148 additional deaths, losses of 11, 6, and 4 months of life per patient, and 12.8 thousand, 576, and 4 thousand YLL by the population due to breast, cervical, and colorectal cancer, respectively, over a 25-year time horizon in Portugal.

CONCLUSIONS

The disruption in cancer screening may contribute to increase cancer morbidity and mortality, with significant YLL. The long-term implications of the impaired cancer screening should be assessed, and proactive measures put in place to mitigate the increase in cancer morbidity, and mortality associated with the COVID-19 pandemic.

Decrease in the number of new cancer diagnoses during the first year of the COVID-19 pandemic - cohort study of 3.5 million individuals in western Poland

Introduction

The COVID-19 pandemic has considerably affected healthcare systems worldwide and is expected to influence cancer incidence, mortality, stage at diagnosis, and survival. This study aimed to assess COVID-19-related changes in cancer incidence observed in 2020 in the Greater Poland region.

Materials and methods

Data from the Greater Poland Cancer Registry on cancer patients diagnosed between 2010 and 2020 were analysed. To quantify the change in the number of incident cancer cases during the COVID-19 pandemic, we calculated the standardized incidence ratio (SIR) and the incidence rate difference (IRD) to assume the pandemic-attributable gap in cancer incidence.

Results

In 2020, in Greater Poland, the expected number of new cancer cases was 18 154 (9 226 among males and 8 927 among females), while the observed number was 14 770 (7 336 among males and 7 434 among females). The registered number of cancer cases decreased in 2020 by 20% (SIR 0·80, 95% CI 0·78 to 0·81) and 17% (SIR 0·83, 95% CI 0·81 to 0·85) in males and females, respectively. Among men, the most significant difference was reported for myeloma (SIR 0·59, 95% CI 0·45 to 0·77), among women for bone cancer (SIR 0·47, 95% CI 0·20 to 0·93). In females the observed incidence was higher than expected for cancer of an unspecified site (SIR 1·19, 95% CI 1·01 to 1·38). In our study, the decrease in new cancer cases was greater in males than in females.

Discussion

The observed incidence was affected in most cancer sites, with the most significant deviation from the expected number in the case of myeloma. An increase in the observed incidence was reported only in women diagnosed with cancer of an unspecified site, which might reflect shortages in access to oncological diagnostics.