Colorectal cancer (CRC), which affects the colon and rectum, is emerging as an important public health concern worldwide. Although traditionally considered more common in Western countries, cases are increasingly being reported in developing nations, including India. Unfortunately, many patients are diagnosed at advanced stages because early symptoms are often ignored or misunderstood.

Timely awareness, lifestyle modification, and appropriate screening can help reduce disease burden. A major international study published recently in The Lancet has now provided important insights into what colonoscopy screening can — and cannot — achieve in preventing colorectal cancer.

What Was the Study About?

The study, known as the NordiCC trial, followed more than 84,000 men and women aged 55 to 64 years from several European countries over a period of 13 years. Participants were randomly divided into two groups: one group was invited for a one-time colonoscopy screening, while the other group did not undergo screening.

Colonoscopy is a medical procedure in which a flexible camera is used to examine the inner lining of the colon and rectum. It can help detect cancer early and also identify precancerous polyps that may later develop into cancer.

Researchers aimed to determine whether a single colonoscopy could reduce both the occurrence of colorectal cancer and deaths caused by the disease.

What Did Researchers Find?

The findings showed that colorectal cancer developed in 1.46% of individuals offered colonoscopy screening compared with 1.80% in the non-screening group. This represents a relative reduction of nearly 19% in colorectal cancer incidence. However, when researchers evaluated deaths caused specifically by colorectal cancer, the difference was smaller and statistically not significant. Colorectal cancer-related deaths occurred in 0.41% of the screening group compared with 0.47% in the non-screening group. In simple terms, the study suggests that colonoscopy can help prevent some colorectal cancers from developing, but its impact on reducing deaths may be more modest than previously believed.

Important Observations from the Study

Researchers observed that colonoscopy appeared more effective in preventing cancers occurring in the lower part of the colon and rectum than those arising in the upper sections of the colon. The study also found somewhat greater benefit among men compared with women, although experts cautioned that these subgroup observations require careful interpretation.

Another important point highlighted by investigators was that participants received only one screening colonoscopy during the study period. In real-world healthcare systems, repeated screening at recommended intervals may potentially influence long-term outcomes differently.

Why These Findings Matter

For many years, observational studies suggested that colonoscopy screening could reduce colorectal cancer deaths by nearly 50%. However, this large randomized controlled trial — considered among the strongest forms of medical evidence — did not demonstrate such a large mortality benefit.

Experts accompanying the publication emphasized that these findings should not discourage participation in screening programmes. Rather, they help provide a more realistic understanding of screening benefits and support evidence-based healthcare planning. The study also highlighted that the overall risk of dying from colorectal cancer in the studied population was already relatively low, which may partly explain why a significant mortality reduction was difficult to demonstrate.

Other Screening Approaches Are Also Available

Alongside colonoscopy, less invasive screening methods such as faecal immunochemical testing (FIT) are increasingly being used worldwide. FIT detects hidden blood in stool samples and can help identify individuals who may need further evaluation with colonoscopy.

Such approaches may improve participation rates because they are simpler, less invasive, and more affordable for large populations.

The future colorectal cancer prevention strategies will likely involve a combination of screening methods, public awareness, and advances in cancer treatment.

What People Should Know

Persistent changes in bowel habits, blood in stool, unexplained weight loss, abdominal discomfort, prolonged constipation, or unusual fatigue should not be ignored, particularly in middle-aged and older adults.

Maintaining a healthy lifestyle may also reduce colorectal cancer risk. Important preventive measures include:

●    Eating a diet rich in fruits, vegetables, and fibre

●    Limiting processed and red meat consumption

●    Avoiding tobacco use

●    No alcohol intake

●    Staying physically active

●    Maintaining a healthy body weight

Conclusion

The NordiCC study provides valuable long-term evidence about colorectal cancer screening. While colonoscopy remains an important tool for detecting and preventing some colorectal cancers, the study suggests that its benefits are more nuanced than earlier assumptions.

For regions like Jammu and Kashmir, where cancer awareness and early detection remain critically important, the message is clear: informed public awareness, healthy lifestyle choices, and timely medical consultation continue to play a major role in reducing the burden of colorectal cancer.

Dr. Umer Majeed Khaja is a cancer biologist and Research Scientist at Sher-i-Kashmir Institute of Medical Sciences, associated with top global cancer research organizations and actively engaged in cancer awareness initiatives in Jammu & Kashmir