Colon cancer in your 20s and 30s? Oncologist explains why even youngsters are not immune to this type of cancer

Colon cancer cases in India: Recent Indian studies suggest that one-third of colorectal cancer patients are under 40, a stark contrast to Western countries where the disease typically peaks after 50 (Image: Pexels)

Bowel cancer, many believed, was something you worried about only after 50, perhaps even later. But  today, young adults, many under 40, are turning up with advanced colorectal cancer, and doctors say the trend is no longer anecdotal. It is real, measurable and deeply unsettling.

"Over the last two decades, we’ve seen a clear shift," Dr Avanish Saklani, Director, Surgical Oncology, Fortis Hospital Mulund, Mumbai, tells Moneycontrol. “Colorectal cancer is no longer confined to older patients. We are now treating people in their 20s and 30s, sometimes even younger, often with this aggressive disease,” he adds.

Recent Indian studies suggest that one-third of colorectal cancer patients are under 40, a stark contrast to Western countries where the disease typically peaks after 50. “In some hospitals, the average age at diagnosis hovers in the late 40s, with a significant proportion far younger,” warns Dr Saklani.

Also read | 6 symptoms of colon cancer: Watch out for sudden weight, fatigue, blood in stool

Part of the danger lies in disbelief, by both patients and doctors. “When a 25-year-old complains of rectal bleeding, it’s often brushed off as piles or a fissure. That delay can be catastrophic,” Dr Saklani explains.

Social discomfort also plays a role. Rectal examinations are avoided, referrals delayed, colonoscopies postponed. By the time a diagnosis is made, many young patients already have advanced tumours, some with aggressive subtypes like signet-ring cell carcinoma.

Causes of colon cancer

Doctors don’t believe genetics alone is to blame. “In fact, inherited syndromes account for only a small fraction of cases.” says Dr Saklani and shares factors that are driving early-onset bowel cancer in India.

Diets low in fibreand high in processed, refined foods

Sedentary lifestyles, obesity and metabolic changes

Environmental exposures, including pesticides and microplastics

Altered gut bacteria linked to diet, antibiotics and pollution

Delayed diagnosis due to stigma and healthcare gaps

Also read | Gastroenterologist explains symptoms of colon cancer, suggests ways to detect it early

“This is a perfect storm of modern living,” says Dr. Saklani. “Young bodies are being exposed to risks they weren’t a generation ago.”

Doctors recommend opportunistic screening, colonoscopies after 50, and earlier testing for anyone with unexplained anaemia, persistent bleeding, weight loss or bowel changes. “Rectal bleeding is never normal. Age is not protection,” Dr Saklani stresses. Early detection saves lives, and with modern minimally invasive and robotic surgeries, outcomes are improving. But awareness is still the strongest weapon.

FAQs on Colon Cancer

Recent trends show that young adults under 40 are increasingly diagnosed with advanced colorectal cancer, unlike past cases where it was more common in people over 50.

Early-onset colon cancer in India is driven by diets low in fibre, high in processed foods, sedentary lifestyles, obesity, environmental exposures, altered gut bacteria, and delayed diagnosis due to stigma.

Any rectal bleeding in young adults should be taken seriously and not dismissed as piles or a fissure, as it may lead to delayed diagnosis of colorectal cancer.

Doctors recommend colonoscopies after 50 and earlier testing for anyone with unexplained anaemia, persistent bleeding, weight loss, or bowel changes to ensure early detection.

Genetics account for only a small fraction of colon cancer cases. Lifestyle, diet, environmental exposures, and healthcare gaps are significant contributors to the increasing incidence among younger populations.