A recent study indicates that initiating fecal immunochemical test (FIT) screening for colorectal cancer (CRC) in individuals aged 40 to 49 yields a 39% decrease in CRC-related deaths and a 21% reduction in the occurrence of the disease, compared to commencing screening at age 50.

The cohort study, conducted within a community setting in Taiwan, has been published in JAMA Oncology.

The study’s authors stated, “These results emphasize the effectiveness of FIT in this younger demographic and reinforce suggestions to lower the initial screening age. Notably the sustained advantages of early screening were consistently seen throughout various study designs and statistical modifications for self-selection bias.”

CRC is increasingly prevalent among younger individuals, with recent statistics revealing notable increases in diagnoses among children, adolescents, and young adults. Since the early 2010s, the incidence of CRC in those under 50 has risen by approximately 3% annually. A recent study also indicated a 500% surge in cases among children aged 10 to 14 over the past two decades. While the total numbers remain relatively small, the rapid increase, diagnoses at later stages, and the absence of apparent risk factors highlight the pressing need to reassess screening approaches for younger age groups.

In this study, researchers examined data from 263,125 adults in Taiwan, aged 40 to 49, who were eligible for biennial FIT screening as part of a national program. Participants were divided into four sub-cohorts based on whether they started FIT screening early (ages 40 to 49) and whether they continued screening after age 50. The study monitored CRC incidence and mortality until 2019, comparing outcomes between early screeners and those who began screening at age 50.

The findings revealed that initiating FIT screening between ages 40 and 49 was linked to a significant decrease in CRC incidence and mortality compared to starting at age 50. Among participants who received early and continued screening (n = 39,315), the CRC incidence rate was 26.1 cases per 100,000 person-years (95% CI, 22.3-29.9), compared to 42.6 cases per 100,000 person-years (95% CI, 40.5-44.7) in the group that began screening at age 50 (n = 223,810). Mortality rates were also lower in the early screening group, with 3.2 deaths per 100,000 person-years (95% CI, 1.9-4.6) vs 7.4 (95% CI, 6.5-8.2).

Moreover,propensity score-matched analyses demonstrated a 21% reduction in CRC incidence (adjusted relative risk [aRR] 0.79; 95% CI, 0.67-0.94) and a 39% reduction in mortality (aRR, 0.61; 95% CI, 0.38-0.98) for early screeners. These results remained consistent in the extended nonadherence adjustment model, with a 25% reduction in incidence (aRR, 0.75; 95% CI, 0.72-0.77) and a 34% reduction in mortality (aRR, 0.66; 95% CI, 0.62-0.71).

“These results provide strong empirical support for lowering the CRC screening age, with substantial public health implications.”

the researchers noted some limitations, including that age- and sex-specific FIT cutoff values were not established when early-age screening was implemented, potentially affecting screening accuracy. Additionally,cultural,genetic,dietary,and health system differences may limit the generalizability of the findings to other populations.

Despite these limitations, the researchers believe their findings align with growing evidence supporting earlier screening and highlight the need for further international research to inform global guidelines.

“this study found that initiating FIT screening at age 40 to 49 years was associated with further reduction in CRC mortality and incidence compared with starting screening at age 50 years,” the researchers concluded.