Screening for colorectal cancer saves lives
Colorectal cancer cases in East and Southeast Asian countries have significantly increased in recent decades, driven by rapid changes in socioeconomic and lifestyle habits, according to a 2023 epidemiology review published in Oncology Reviews.
Based on the most recent incidence data reported in GLOBOCAN 2020 from the International Agency for Research on Cancer (IARC), the Asian countries with the highest incidence of colorectal cancer include Japan, China, Singapore, and South Korea. In the Philippines, colorectal cancer is the third most common cancer and the fourth leading cause of cancerrelated deaths. Colorectal cancer is now in the top three most common cancers in many Asian countries, the review stated.
March is National Colorectal Cancer Awareness Month, while March 10-16 is Philippine Digestive Health Week (PDHW).
Systematic reviews of colorectal cancer in Asian confirm that excessive consumption of red meat, processed meat, preserved food, saturated/animal fat, cholesterol, high sugar food, spicy food, tubers, or refined carbohydrates are risk factors for colorectal cancer. Moreover, an increasing number of Asians have sedentary lifestyles and are obese, which are both risk factors for colorectal cancer.
To reduce colorectal cancer risk, the Philippine Society of Gastroenterology (PSG) recommends maintaining a healthy weight; engaging in regular physical activity; eating a diet rich in vegetables, fruits, and whole grains, and low in red and processed meat; and refraining from drinking alcohol and cigarette smoking.
Common symptoms of colorectal cancer include a change in bowel habits; blood in or on one’s stool; diarrhea, constipation, or feeling that the bowel does not empty all the way; abdominal pain, aches, or cramps that don’t go away; and unexplained weight loss. However, precancerous polyps and colorectal cancer do not always cause symptoms, especially in the early stages of the disease. This is why individuals need to get screened even if they do not have a family history, as most colorectal cancers occur in people with no family history of the disease, stressed the US Centers for Disease Control and Prevention (CDC).
With early detection, colorectal cancer is one of the most preventable and treatable cancers. The epidemiology review noted that colorectal cancer is an ideal disease for screening given its population-based estimates of prevalence, the presence of early precursor lesions, and the effectiveness of various fecal and structural visualization methods of the colon and rectum.
Screening helps prevent colorectal cancer by finding precancerous polyps (abnormal growths) so they can be removed before they turn into cancer. With early detection through screening, treatment can be very effective. Almost 88% of adults diagnosed with colorectal cancer at an early stage live for five years or more, compared to only 16% of those diagnosed with late-stage colorectal cancer, said the CDC.
According to the epidemiology review, the likelihood of finding colorectal cancer-related cancerous lesions triples in patients in Asia aged over 50 years. The PSG recommends regular screening through fecal immunochemical test (FIT) and colonoscopy starting age 50 for the prevention, early detection, and treatment of early-stage colorectal cancer.
FIT is a simple test that can be performed at home. Recommended yearly, it detects hidden blood in the stool, which can be an early sign of cancer. However, FIT cannot diagnose colorectal cancer. As such, individuals with positive FIT results should schedule a colonoscopy with a gastroenterologist. A colonoscopy is an exam in which a long, flexible tube (colonoscope) is inserted into the rectum. A tiny video camera at the tip of the tube allows the gastroenterologist to view the inside of the entire colon and rectum to check for changes or abnormalities.
Given the changing colorectal cancer trends in Asian populations, the epidemiology review recommends a shift in public health priorities. It recommended that colorectal screening in Asian countries be made a national health priority, and extensive studies be conducted to determine barriers to colorectal cancer screening.
The review called for public education campaigns on the importance of cancer prevention and the engagement of physicians with primary healthcare. It also recommended an in-depth evaluation of the public acceptance of a wide variety of screening modalities based on cultural factors, which can contribute to determining the risk stratification in colorectal cancer screening along with the availability of public health resources.
The epidemiology review noted that a key factor in early colorectal cancer detection and cancer control is the development of a cancer registry. The main objective of the cancer registry is to build a system to collect and organize data on all cancer cases from various cancer institutions such as cancer hospitals in order to build statistical models, such as polygenic models, to determine the progression of cancer within a population. Cancer registries help clinicians to make personalized follow-up treatments for patients and to serve as a surveillance system for at-risk individuals. Centralized database management integrated into a cancer registry can also provide a cancer epidemiological tool for researchers, the review stated.
TEODORO B. PADILLA is the executive director of Pharmaceutical and Healthcare Association of the Philippines (PHAP). PHAP represents the biopharmaceutical medicines and vaccines industry in the country. Its members are in the forefront of research and development efforts for COVID-19 and other diseases that affect Filipinos.