Taiwan study finds early screening lowers colorectal cancer risk

Taipei, July 3 (CNA) A National Taiwan University Hospital (NTUH) study has provided the first real-world evidence that screening those in their 40s for colorectal cancer significantly lowers both incidence and mortality compared to starting at 50.

Taiwan has a high colorectal cancer incidence rate, with the rate among people aged 40-49 ranking among the top three globally, Chiu Han-mo (邱瀚模), the director of NTUH's Health Management Center, said at a news conference in Taipei.

Data from the Health Promotion Administration also showed that colorectal cancer was the second most common cancer in Taiwan in 2022, with 17,643 cases reported that year, behind lung cancer with 17,982 cases.

"A few years ago, many people said we should wait to see what Western countries would do [to address the high incidence rate] before making our own decisions," said Chiu, who also serves as a clinical professor at NTU College of Medicine.

"But we believe Taiwan faces unique challenges [due to its relatively high rate of colorectal cancer among 40-49 year olds] that must be addressed locally. This is why we sought an evidence-based foundation to advance [screening] policy," he added.

With that goal in mind, Chiu's team began analyzing 17 years of data from community-based screening programs tracking over 500,000 individuals in Keelung and Tainan.

Some of the individuals in the study started receiving fecal immunochemical test (FIT) screenings between the ages of 40 and 49 through local government funding, while others started at 50 under central government funding.

After spending the past two years studying and developing models based on those data, Chiu's team found that those who started FIT screening at 40-49 have 21-25 percent lower risk of developing colorectal cancer and a 34-39 percent reduction in related deaths compared to those started at 50.

The study also found that for every 1,548 individuals screened before age 50, one case of colorectal cancer could be prevented -- -- significantly more efficient than the 2,079 needed when screening begins at age 50.

Asked why screening can lower cancer incidence and mortality, Chiu said it helps detect precancerous lesions so they can be treated before developing into cancer, and also catches cancer early before it progresses to a late stage and leads to death.

Published on June 12 in JAMA Oncology, a peer-reviewed journal of the American Medical Association, the study is the world's first to provide real-world evidence of the benefits of early colorectal cancer screening.

It was accompanied by an editorial from three Harvard Medical School researchers highlighting the significance of the findings.

One of the Harvard researchers, Andrew Chan, said that in the United States, data on earlier screening -- such as beginning at age 40 -- and on the use of FIT have been "lacking," and Chiu's study is significant because it helps "address this important evidence gap."

This study can be used to "support FIT screening in lower-resource settings where colonoscopy screening was not an option and provide additional evidence for us to potentially lower our screening age even further," said Chan, who joined the press event via videoconference.

Since Jan. 1 this year, Taiwan has expanded eligibility for biennial government-subsidized FITs to include individuals aged 45-49, lowering the previous age range of 50-74.

Individuals aged 40-44 with a family history of colorectal cancer are now also eligible for the tests following the expansion.

Chiu welcomed the expansion and said the move is highly cost-effective, as people aged 45 to 49 are a vital part of the workforce, noting, "If we can reduce their risk of developing colorectal cancer, the impact on the country would be tremendous."