Yuri Nakamura, 44, Dies of “Rectal Cancer”… Specialist Warns of “Colon Cancer,” Which Is on the Rise Among Younger Generations: Signs You Can’t Ignore

On September 1, actress Yuri Nakamura passed away at the age of 44 due to rectal cancer.

While expressions of grief over Nakamura’s untimely death continue to pour in, new news broke on September 30.TOSHI-LOW, the lead vocalist of the four-piece rock band “BRAHMAN,” announced that he had been diagnosed with “sigmoid colon cancer (colorectal cancer).” He is scheduled to undergo surgery in the near future with the aim of a complete cure and will then take time off to recover.

In July of this year, it was revealed that Hitoshi Matsumoto (63) of the comedy duo “Downtown” had also undergone surgery to remove a tumor from his colon, and he publicly confirmed that it was “cancer.”

Looking back over the past few years, there have been quite a few celebrities who have gone public with their colorectal cancer diagnoses. Actor Jun Hashizume (65), author Keigo Higashino (who passed away this past July), and Wasabi (37), the drummer for “Wagakki Band”—cases have been occurring one after another across various fields.

“Colon cancer again?”

Seeing these news stories one after another, perhaps some people have felt this way.

Of course, the mere fact that celebrities continue to go public with their diagnoses does not mean that colorectal cancer has recently surged.

However, in recent years, “early-onset colorectal cancer”—which develops in people under the age of 50—has been attracting global attention.

An international study conducted by the National Cancer Center and others reports that the incidence rate of colorectal cancer among people aged 20 to 49 is rising in multiple countries and regions, and in some cases, the mortality rate is also increasing.

Given the common perception that “colon cancer is a disease of the elderly,” why is it on the rise among younger generations? What symptoms should people watch out for?

We spoke with Dr. Naoki Miyata, Director of the Miyata Gastroenterology and Dermatology Clinic, a gastroenterologist, and a specialist in gastrointestinal endoscopy, who has examined the colons of more than 10,000 patients (quotes below are from Dr. Miyata).

“Simply eating more meat” does not explain the trend

“Colon cancer is a very common form of cancer among Japanese people. The risk of developing colon cancer increases with age. The high number of patients is due to Japan’s aging population. However, At the same time, early-onset colorectal cancer—which develops in people under 50—has been attracting global attention in recent years. We can no longer simply think of colorectal cancer as ‘a disease of the elderly.’”

Why has the number of colorectal cancer patients in Japan increased? A common explanation is the “Westernization of the diet.” This theory attributes the rise to a shift from a diet centered on rice and grains to one high in meat, dairy products, and fats. However, Dr. Miyata states that the increase in colorectal cancer cannot be explained by a single factor—namely, “eating more meat and fat.”

“While a link has been pointed out between the consumption of red meat and processed meat and the risk of colorectal cancer, this disease cannot be explained by that alone. Colorectal cancer is linked to various factors, such as alcohol consumption, smoking, obesity, and lack of exercise, as well as genetic factors. We should consider it a disease caused by a combination of multiple factors.”

We cannot single out a single food as the culprit by saying, “I got colorectal cancer because I ate this.” So, what is the reason for the rise in colorectal cancer among younger generations? In recent years, very interesting research findings have been reported regarding the “gut microbiome.”

Traces of “colibactin” found in about 70 percent of those under 40

Research is underway on “gut bacteria” as one of the clues to solving the mystery of early-onset colorectal cancer. Of particular interest is a substance called “colibactin,” produced by certain strains of E. coli.

“Colibactin damages cellular DNA. It is known that when DNA is damaged, traces of genetic mutations characteristic of colibactin remain.”

In an analysis of 200 Japanese colorectal cancer patients published in 2026 by the Institute of Medical Science at the University of Tokyo and others, traces of mutations associated with colibactin were confirmed in about half of the cases. What drew particular attention in this analysis was the group of “young patients.”It was reported that approximately 70 percent of patients who developed colorectal cancer before the age of 40 showed traces of colibactin-related mutations.

Whole-genome analyses of 981 colorectal cancer cases across 11 countries, including Japan, have also confirmed mutations associated with colibactin.These mutations were observed in about half of the Japanese cases, and it was reported that “colorectal cancer diagnosed before age 50” had 3.3 times more colibactin-related mutations than colorectal cancer diagnosed in patients aged 70 or older.

What is particularly interesting is that evidence suggests DNA damage caused by colibactin may not have occurred immediately before the cancer was detected, but rather began decades before onset—possibly as early as childhood.

“We cannot immediately conclude that ‘colibactin is the cause of early-onset colorectal cancer,’ nor is it premature to interpret this as meaning that ‘improving gut health can prevent colorectal cancer.’ At this stage, the research is still ongoing, and this is a field that will be further elucidated in the future.The causes of early-onset colorectal cancer are not yet fully understood. However, there is no doubt that this is a very important study in considering the relationship between gut bacteria and colorectal cancer.”

Research is now beginning to explore not only the lifestyle and genetic factors that have long been recognized but also the possibility that DNA damage caused by gut bacteria accumulates from a very early stage in life. Along with identifying the causes, another critical issue is how to detect colorectal cancer in younger people as early as possible.

Bleeding from cancer in the “right colon” is unusual

When people in their 20s and 30s experience bloody stools, few would suspect colon cancer right away.

“The younger you are, the more likely you are to assume, ‘I probably don’t have colon cancer.’ Even if you have blood in your stool, you might think, ‘It’s probably just hemorrhoids,’ or if your stomach feels upset, you might think, ‘It’s probably just stress.’ However, colorectal cancer is not a disease that young people are immune to. It’s important not to ignore symptoms simply because of your age.”

While colorectal cancer may have few noticeable symptoms in its early stages, symptoms can appear depending on the location of the lesion and the extent of the disease. One symptom to watch out for is “blood in the stool.”

“When people hear ‘blood in the stool,’ I think many immediately think of hemorrhoids. While bleeding from hemorrhoids isn’t uncommon, I want you to avoid self-diagnosing by thinking, ‘I have hemorrhoids, so this blood must be from them too.’ Distinguishing this bleeding from that caused by colon cancer or polyps can’t always be done without a proper examination.”

Just because it’s colorectal cancer doesn’t necessarily mean there will be visible blood in the stool. In particular, with cancers that develop in the “right side of the colon,” even without visible blood in the stool, small amounts of bleeding may persist chronically, and iron-deficiency anemia may be the first sign leading to diagnosis.

“Please pay attention not only to bloody stools but also to changes such as persistent constipation or diarrhea, a persistent narrowing of the stool, or a feeling that you haven’t fully emptied your bowels. If you’re diagnosed with iron-deficiency anemia of unknown cause, it’s important to check for bleeding from the digestive tract.”

Symptoms you might dismiss as “just hemorrhoids” or “just constipation” could actually be your body’s SOS signal. The key to colon cancer is early detection and prompt, appropriate treatment. If detected early, depending on the nature of the lesion, some cases can be treated by removal via colonoscopy.

This is precisely why colorectal cancer screening—even before symptoms appear—is so important. In Japan, colorectal cancer screening using fecal occult blood tests is available for people aged 40 and older.

“The fecal occult blood test is a proven and effective screening method that has been shown to reduce colorectal cancer mortality rates. However, it cannot detect all cases of colorectal cancer in a single test. If your fecal occult blood test comes back positive, please do not ignore it by thinking, ‘It’s just hemorrhoids’ or ‘It’s probably just a fluke.’If you test positive, be sure to undergo a follow-up examination, such as a colonoscopy.”

It is important to understand that “colorectal cancer screening” and “medical consultation for those with symptoms” are two distinct things.

“Screening is generally intended for people without symptoms. Just because you’re under 40 doesn’t mean you have to wait until you reach the recommended screening age if you’re experiencing symptoms such as blood in your stool. Also, if you have a blood relative—such as a parent, sibling, or child—who has had colorectal cancer, especially if they were diagnosed at a young age, please be sure to inform your doctor of this family history.”

Instead of thinking, “I’m not 40 yet, so colon cancer screening can wait,” you should seek medical attention if you have symptoms, regardless of your age. It’s important to keep this distinction in mind.

So, what can we do to protect ourselves from colorectal cancer?

“You cannot prevent colorectal cancer with specific foods or supplements alone. First, avoid smoking and limit alcohol consumption. Maintain a healthy weight and stay active. And strive for a well-balanced diet. Basic lifestyle habits are crucial.

On top of that, once you reach the recommended screening age, get regular colorectal cancer screenings. And regardless of your age, if you notice any concerning symptoms or signs—such as blood in your stool, changes in bowel habits, or unexplained iron-deficiency anemia—don’t ignore them; see a doctor right away.”

While much remains unknown about colorectal cancer in young people, research on colibactin has suggested that changes leading to the “onset” of cancer may occur decades before the cancer is actually detected. As research progresses, it may not only help unravel the mystery of why colorectal cancer is increasing among younger generations but also lead to future preventive measures and early detection.

For now, the most important thing is not to assume, “I’m young, so I’ll be fine.” Not overlooking signs from your body—such as blood in the stool or changes in bowel habits that differ from what you’re used to—and seeking the necessary tests is the first step toward early detection.