Study Examines the Impact of Pre-Diagnostic Colonoscopy on Colorectal Cancer Mortality
Understanding Colorectal Cancer Development
The emergence of colorectal cancer is a gradual process that unfolds over time, allowing for the possibility of early screening and detection of pre-cancerous polyps before they advance to cancer. Effective screening methods can identify these early-stage conditions, highlighting the significance of regular colorectal cancer screenings.
Proven Benefits of Colorectal Cancer Screening
Numerous studies have documented that colorectal cancer screening contributes to a decrease in both the incidence and mortality rates of this disease. However, despite these advancements, colorectal cancer remains the second leading cause of cancer-related deaths in the United States, underscoring the necessity for enhanced efforts to mitigate its associated morbidity and mortality.
The Role of Pre-Diagnostic Colonoscopy
A colonoscopy is a diagnostic procedure that inspects the entire large intestine using a flexible tube equipped with a camera. A pre-diagnostic colonoscopy is conducted to identify pre-cancerous polyps or colon cancer in asymptomatic patients, whereas a diagnostic colonoscopy is performed in response to gastrointestinal symptoms like abdominal pain or rectal bleeding. Given the slow progression of colorectal cancer, pre-diagnostic screenings are crucial for early detection.
Recent Research on Colonoscopy and Survival Rates
Researchers from the University of South Australia investigated the relationship between pre-diagnostic colonoscopy and patient survival rates using data from South Australia. Their findings were published in BMC Cancer and included a cohort of 12,906 patients diagnosed with colorectal cancer from 2003 to 2013. Among these patients, 37% had undergone a pre-diagnostic colonoscopy, with an average interval of 1.5 years between the initial procedure and cancer diagnosis. The analysis revealed that 29% of these patients succumbed to colorectal cancer.
Link Between Pre-Diagnostic Colonoscopy and Reduced Mortality
The study’s results indicated that one pre-diagnostic colonoscopy was linked to a 17% reduction in colorectal cancer mortality. Furthermore, patients who underwent two pre-diagnostic screenings experienced a 27% decrease in cancer deaths, while those with three or more procedures saw a 45% reduction in mortality. This data clearly demonstrates that increasing the number of pre-diagnostic colonoscopies correlates with a significant drop in the risk of dying from colorectal cancer.
Enhanced Survival Rates Through Screening
The research highlighted that patients who had pre-diagnostic colonoscopy exhibited higher survival rates compared to those who received the procedure after cancer symptoms emerged. The U.S. Preventive Services Task Force recommends screening every two years for individuals aged 50 and older. Effective screening strategies, including fecal occult blood tests, colonoscopy, and CT colonography, are essential for the early diagnosis of colorectal cancer and for reducing its associated morbidity and mortality.
Encouraging Increased Participation in Screening
A significant number of individuals do not engage in recommended colorectal cancer screenings, thereby missing opportunities for early detection and timely treatment that could potentially cure the disease. The authors emphasize that multiple pre-diagnostic colonoscopy procedures, especially when the initial procedure occurs more than a year before diagnosis, are associated with improved survival rates following a colorectal cancer diagnosis.
Conclusion
These findings reinforce the importance of colorectal cancer screening, particularly when conducted at least one year prior to the onset of symptoms. There is a pressing need to enhance awareness of the benefits and effectiveness of colorectal cancer screening among healthcare providers and the general population to further decrease mortality rates associated with this condition.
Written by Preeti Paul, M.Sc.
Reference: Ming Li et al., Pre-diagnostic colonoscopies mortality-results from linked population-based data in South Australia. BMC Cancer 19, Article number: 856 (2019)
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