Page 10 - Zheng Feng
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Chapter 1
COLORECTAL CANCER EPIDEMIOLOGY
Colorectal cancer (CRC) is a major public health problem. According to the data in GLOBOCAN
(2018), CRC is the second most common cancer in women and the third most common cancer
in men, and the second leading cause of cancer-related death in the world. Globally, more
than 1.8 million new cases were diagnosed and approximately 881,000 people died from CRC
[1]
in 2018 . Worldwide, the average age-standardized annual incidence per 100,000 of CRC in
[2]
th
both sexes is 19.7 (male: 23.6 and female: 16.3) . In 2018, the Netherlands was ranked 10
with an age-standardized incidence of 37.8 patients per 100,000 inhabitants .
[3]
The development of CRC is influenced by a number of demographic, behavioral, and
environmental factors. According to the World Cancer Research Fund (WCRF)/American
Institute for Cancer Research’s (AICR) 2018 third expert report, inflammatory bowel disease
and risk factors such as aging, smoking, overweight or obesity, high red meat or saturated fat
intake, low fruit and vegetable consumption and low physical activity have shown to increase
CRC incidence. Other dietary habits and lifestyle factors, including physical activity, sufficient
intake of whole grain, dietary fiber and dairy products, regular consumption of vitamin D,
calcium and multivitamin supplements, are protective factors that potentially decrease the
risk of CRC .
[4]
The incidence of CRC has been steadily rising. By 2030, it is estimated that the incidence and
mortality will increase by 60% to more than 2.2 million and 1.1 million respectively . These
[5]
figures illustrate the current and future economic burden on society through either direct
costs related to treatment and indirect costs due to cancer-related productivity loss .
[6]
COLORECTAL CANCER SCREENING
The vast majority of CRCs develop from precursor lesions called colorectal adenomas, which
are small noncancerous lesions in the inner layer of the colon and rectum. It usually takes
[7]
several years to even decades to complete the malignant transformation to carcinoma .
The survival rates of CRC are inversely correlated with the cancer stage at diagnosis, with
5-year survival rates of 90% for early-stage CRC (stage 0 and I according to the tumor-lymph
node-metastasis (TNM) classification) to 10% in patients with advanced-stage cancer (stage
IV) [8, 9] . Implementing CRC screening contributes to a decrease in incidence and mortality
rates [10] , emphasizing that regular screening and early removal of CRC and its precursor
lesions are effective strategies to manage the disease and increase survival [11, 12] .
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