Blood in the Stool in Young People: Just Hemorrhoids? Persistent Symptoms Require Colorectal Cancer Screening

[Sportschosun, Jang Jong-ho] Starting in 2028, the eligible age for colorectal cancer screening will be lowered from 50 to 45, and the screening method will change from a fecal occult blood test to colonoscopy. These changes are included in the 5th Comprehensive Cancer Control Plan approved by the National Cancer Management Committee under the Ministry of Health and Welfare (MOHW) in February. The age reduction is driven by the rise in colorectal cancer among younger people.

According to the 2023 National Cancer Registration Statistics, colorectal cancer accounts for 11.3% of all cancer cases in South Korea, making it the third most common cancer. It occurs about 1.4 times more often in men than in women and is most common among men in their 50s. Fortunately, treatment outcomes rank among the best in the world. The five-year relative survival rate for colorectal cancer rose from 56.2% in 1993–1995 to 75.6% in 2019–2023. When the cancer is detected while confined to the colon or rectum, the rate reaches 94.9%. The concern is the age at which it develops.

According to cancer registration statistics from the Korean Statistical Information Service (KOSIS), the number of newly diagnosed colorectal cancer patients aged 20 to 39 rose from 864 in 2018 to 1,948 in 2023—an increase of more than 125% in five years. This is considerably higher than the increases among patients in their 40s and 50s, which were 42.9% and 9.8%, respectively, over the same period.

Park Go-woon, a professor of colorectal and anal surgery at Soonchunhyang University Bucheon Hospital, said, "Most colorectal cancer patients are still middle-aged or older, but I have clearly been seeing more patients in their 20s to 40s than before. In particular, younger patients are not eligible for screening, so they often visit the hospital only after symptoms develop. As a result, the cancer is frequently detected at a more advanced stage."

◇The Rise in Colorectal Cancer Among Young People Cannot Be Explained by Diet Alone

Colorectal cancer develops through a combination of genetic factors and lifestyle habits. Major risk factors include older age, a family history, genetic conditions such as Lynch syndrome and familial adenomatous polyposis (FAP), and inflammatory bowel disease. Obesity, lack of exercise, smoking, excessive alcohol consumption, and high intake of processed meat and red meat also increase the risk.

The causes of the increase in colorectal cancer among young people have not yet been clearly identified. Westernized diets, obesity and metabolic diseases, insufficient exercise, and increased consumption of processed foods have been cited as contributing factors, but they do not fully explain the scale of the increase. Researchers are also examining the possibility that multiple factors—including environmental exposures accumulated from childhood and changes in the gut microbiome—may influence the development of the disease.

◇Persistent Bloody Stool or Changes in Bowel Habits Require Testing

Colorectal cancer often causes no symptoms in its early stages. As it progresses, symptoms may include bloody stool, changes in bowel habits, changes in stool caliber, abdominal pain or bloating, weight loss, anemia, and fatigue. People with recurrent bloody stool or changes in bowel habits should not assume that the cause is hemorrhoids and should undergo testing.

Symptoms vary depending on where the cancer develops. Right-sided colon cancer may be detected through anemia and fatigue caused by chronic bleeding rather than visibly bloody stool. Bloody stool and changes in bowel habits are relatively common with left-sided colon cancer and rectal cancer.

◇Personalized Care for Colorectal Cancer, from Testing to Treatment

The most important tests for diagnosing colorectal cancer are colonoscopy and biopsy. Once colorectal cancer is confirmed through a biopsy, CT scans of the abdomen, pelvis, and chest are used to assess the stage. For rectal cancer, pelvic MRI is important for evaluating how deeply the tumor has invaded the rectal wall and whether nearby lymph nodes are involved. In advanced colorectal cancer, tests are also performed to identify tumor markers and the tumor’s molecular characteristics. This helps doctors tailor additional treatment after surgery, as well as chemotherapy, targeted therapy, or immunotherapy, to the tumor’s specific features.

Treatment is also changing. Doctors now determine the treatment approach through personalized care that considers not only the cancer’s location and stage but also the patient’s age and overall health, along with the tumor’s genetic, molecular, and biological characteristics.

Early colorectal cancer can be treated with endoscopic resection alone. Colon cancer is primarily treated with surgery, followed by postoperative chemotherapy depending on the stage. For rectal cancer, total neoadjuvant therapy (TNT), which involves intensive chemotherapy and radiation therapy before surgery, has recently become a major treatment strategy. In some patients whose tumors have completely disappeared after treatment, doctors may consider preserving the rectum and bowel function through nonoperative surveillance rather than proceeding immediately with surgery. However, this decision must be made carefully, taking the patient’s treatment response and risk of recurrence into account.

Even in metastatic colorectal cancer, surgery may aim for a cure depending on the extent of metastasis. Recently, targeted therapy or immunotherapy may also be used based on the tumor’s molecular characteristics.

Park said, "The more complex the situation—for example, in older patients, those with multiple underlying conditions, or those with locally advanced rectal cancer or metastatic colorectal cancer—the more important it is to consider the patient’s overall health and quality of life together with the tumor’s characteristics, rather than simply applying a standard treatment protocol."

She added, "To prevent colorectal cancer, an overall healthy lifestyle is far more important: getting enough fiber, reducing processed meat, and managing your weight and exercise. Screening is even more important. If you have a family history or a history of polyp removal, it is advisable to undergo regular screening earlier than the general recommended age."

Jang Jong-ho, bellho@sportschosun.com

This article has been translated by GripLabs Mingo AI.