New screening guidelines can save lives: researchers find a major increase in colorectal cancers at an early stage in eligible 45 to 49 year olds.
Study: incidence of colorectal cancer in American adults after recommendations for previous screening. Image credit: Kateryna Kon / Shutterstock.com
Colorectal cancer (CRC) is one of the main killers in the United States. The registered screening age for CRC has recently been lowered to 45, followed by an increase in screening rates. This coincided with a higher CRC incidence. A recent study in Jama Examined if it results from successful screening or reflected a real increase in the incidence of the disease.
Introduction
There were, on average, 37 new CRC cases per 100,000 people each year, with an annual mortality of ~ 13 per 100,000, during the period 2018-2022.
While CRC screening in the United States began at 50, the American Cancer Society and the US Preventive Services Task Force (USPSTF) recommended that the screening threshold is reduced to 45 years in 2018 and 2021, respectively. Following these recommendations, data on survey and insurance complaints indicated an increase in CRC screening activity in adults between 45 and 49 years in 2018-2022, as well as an increase in the number of CRC diagnoses.
This study aimed to understand the reason for this increase in the incidence of the CRC. Investigators examined CRC cases in adults between 20 and 54 years from 2004 to 2022.
Study results
The files revealed 219,373 cases of CRC, with an average age of 47 years. From 2004, the incidence of the CRC increased regularly by 1.6% each year among the 20 to 39 year olds. In the group aged 40 to 44, the increase was 2.6%.
For adults between 45 and 49 years, the annual incidence increased by 1.1% until 2019, but increased quickly by 12% each year from 2019 to 2022. Among the 50 to 54 year olds, it increased by 2.0%.
Thus, all groups have shown a stable increase in incidence, except in the newly eligible group for screening. In this group, most of the new tumors detected were local stadium tumors, with an annual percentage variation of around 22%. The incidence of localized tumors increased by 25% in 2021 compared to 2019 and by 50% in 2022 compared to 2021. This contrasts with the stable rates observed from 2004 to 2019.
Stratification by location, colon cancer rates showed an annual percentage variation of ~ 18.8% in 2019 at 2022, against 25.1% for rectum cancer. Again, the two points came after a period of stable or decreasing incidence.
In all other age groups, cancer rates in the local stadium did not show this tip. In the group aged 20 to 39, the localized incidence of cancer remained stable, while in the other two groups, it experienced much lower increases (ranging from 2.5% to 3.1% per year).
Advanced cancer rates showed an increase of 1.7% to 2.9% per year during the period starting in 2004 in people less than 45, but the last ten years have experienced a clearer increase between 45 to 54 years.
It is important to note that the 2020 data has been excluded from trend analyzes due to disruptions related to pandemic in cancer diagnostics.
Conclusions
The study shows that after being stable for about 15 years, local CRC levels have increased sharply in adults between 45 and 49 years from 2019 to 2022. The most significant relative increase was 2021 to 2022, from 50%. On the other hand, advanced cancer diagnoses remained stable in the same age group.
The increase in CRC diagnoses in adults between 45 and 49 could reflect increased diagnostics in 2021 after missing opportunities due to the pandemic. Although this could be an explanation, the USPSTF did not recommend reducing the age of screening in 2021. In addition, the increase reflected only the disease at an early stage in the age group which was freshly raised under the screening umbrella and became more steep in 2022.
A more plausible explanation could be that it “Probably reflects the diagnosis of asymptomatic cancer widespread by the first time by the first screening due to the recommendations for adults to start screening at 45 years instead of 50 years. «
However, the study authors warn that only four years of post-reward data are currently available, and the impact of the pandemic can still confuse the results. The results indicate that an increase in CRC detection at an early stage is a promising result of adult screening for disease at a younger age.
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