Colorectal cancer in a 41-year-old London woman: symptoms initially dismissed

For several months, persistent digestive symptoms in this 41-year-old woman were treated as minor complaints.

Her experience highlights a point that is not always widely understood: colorectal cancer does not affect only older people. In younger adults, warning signs can be dismissed, particularly when they resemble common digestive problems. For this London woman, a decisive investigation was only carried out after she continued to press for it.

Bleeding initially put down to haemorrhoids

Her story began in September 2021. The patient, then 41, noticed rectal bleeding. During a telephone appointment with her GP, haemorrhoids were suggested as the likely cause. At the time, this appeared credible, as this very common condition can indeed cause blood to appear after a bowel movement.

Her symptoms did not go away. Over the following months, she also experienced a family bereavement, delaying further attempts to seek medical care. Then, after an episode of Covid-19, her digestive issues continued. Doctors subsequently considered food poisoning as a possible explanation.

Because the symptoms had lasted so long, she eventually requested a faecal immunochemical test. This test detects blood in stool that cannot be seen with the naked eye. It came back positive, and events then moved quickly: a colonoscopy was arranged in April 2022.

The colonoscopy revealed a six-centimetre tumour in the rectum. It was diagnosed as stage 3 colorectal cancer.

By this point, the disease had spread to lymph nodes close to the tumour, but no distant metastases had been found. This difference has major implications for both treatment planning and patient follow-up.

A lengthy course of care involving successive treatments

Stage 3 colorectal cancer generally requires combined treatment. In this London woman's case, the medical team first opted for five weeks of chemoradiotherapy. This combination is intended to shrink the tumour through targeted radiation and anti-cancer medicines.

Following this initial phase, the margins required for surgery did not appear sufficient. The patient therefore underwent a further twelve weeks of chemotherapy. Surgeons then removed the entire tumour during an operation lasting six hours.

A temporary stoma was created during the procedure. This is an opening in the abdomen that diverts stool into a bag. It can give the operated area time to heal before normal bowel function is restored.

• Five weeks of chemoradiotherapy began her treatment pathway.
• Twelve weeks of chemotherapy took place before surgery.
• A six-hour operation enabled the tumour to be completely removed.
• A further twelve-week course followed surgery.
• Her bowel function was restored in August 2023.

After treatment, the woman changed careers. She now works in London supporting people undergoing rehabilitation after cancer.

Why colorectal cancers in under-50s are causing concern

Her case forms part of a trend being closely monitored by specialists. In the United States, data published in 2026 by the American Cancer Society show a marked increase in diagnoses among younger adults. Rectal and sigmoid cancers are especially affected.

According to these estimates, 45% of colorectal cancer diagnoses now involve people under 65, compared with 27% in 1995. Among under-50s, incidence is rising by around 3% each year in the United States.

In younger patients, diagnosis often happens late: symptoms that may appear ordinary can sometimes delay access to specialist investigations.

The precise reasons for this increase have not been fully established. Researchers are examining, among other factors, obesity, physical inactivity, dietary habits, certain chronic inflammatory conditions and changes in the gut microbiome. It remains difficult to determine how much each factor contributes.

Warning signs that should not be dismissed

Rectal bleeding does not automatically mean cancer. Haemorrhoids, an anal fissure or inflammatory bowel disease may also be responsible. However, a symptom that persists, keeps returning or occurs alongside other changes warrants a thorough medical assessment.

Signs that should prompt someone to seek medical advice include:

• repeated blood in stool or on toilet paper;
• a lasting change in bowel habits, including unusual diarrhoea or constipation;
• regular abdominal pain or a feeling that the bowel has not fully emptied;
• unusual tiredness linked to possible anaemia;
• unexplained weight loss;
• a family history of colorectal cancer or polyps.

Faecal testing and colonoscopy serve different purposes

The faecal immunochemical test is a straightforward tool. It is carried out at home using a stool sample and looks for traces of blood that are not visible. A positive result does not mean cancer is present. However, it does mean that the cause needs to be investigated, usually with a colonoscopy.

A colonoscopy allows a gastroenterologist to directly examine the lining of the colon and rectum. It can also be used to remove polyps, small growths which may develop into a malignant tumour over time. A polyp often takes ten to fifteen years to become cancerous, leaving an opportunity for action when screening takes place early enough.

In France, organised colorectal cancer screening is offered to women and men aged 50 to 74 who have no particular symptoms and no high family risk. The test is offered every two years. A younger person experiencing bleeding, lasting fatigue or persistent changes in bowel habits should not wait until they reach screening age: they should seek medical advice.

Stage 3 colorectal cancer: locally advanced disease

A cancer stage describes how far the disease has spread at the time of diagnosis. In stage 3 colorectal cancer, tumour cells have reached nearby lymph nodes without invading distant organs such as the liver or lungs. Treatment often combines surgery, chemotherapy and sometimes radiotherapy, especially when the tumour is located in the rectum.

Prognosis is influenced by many factors: the tumour's exact location, the number of affected lymph nodes, response to treatment, the person's general health and the consistency of follow-up. When the disease remains localised, the prospects for long-term control are considerably better. This is why taking symptoms seriously at an early stage is so important.