Rectal Cancer: Causes & Symptoms

Rectal cancer develops in the rectum, the final part of the large intestine. Its causes include genetic mutations, lifestyle factors, and medical conditions like inflammatory bowel disease. Symptoms of rectal cancer range from changes in bowel habits to rectal bleeding and unexplained weight loss. Early detection is key to effective rectal cancer treatment, which may involve surgery, chemotherapy, and radiation therapy. If you’re in Bangalore, consulting an oncologist in Bangalore can ensure personalised care and better outcomes.

Understanding Rectal Cancer

What is rectal cancer? It is a type of cancer that forms in the rectum, the last segment of the large intestine before the anus. Often grouped with colon cancer under the umbrella term colon and rectal cancer, it differs in location and treatment approach. Like many cancers, rectal cancer starts with abnormal cell growth, forming polyps that may become malignant over time. Rectal cancer staging helps determine its progression and guides treatment plans.

Symptoms of Rectal Cancer

Rectal cancer symptoms vary but often include:

• Changes in bowel habits: Persistent diarrhoea, constipation, or the feeling of incomplete evacuation.
• Rectal bleeding: Bright red blood in the stool or bleeding during bowel movements.
• Abdominal discomfort: Cramping or pain in the lower abdomen.
• Narrow stools: A change in stool shape or consistency can indicate a blockage.
• Unexplained weight loss: Losing weight without dietary or exercise changes.
• Fatigue: Ongoing tiredness may be linked to anaemia caused by bleeding.
• Mucus in stool: An unusual discharge may signal a problem in the rectum.

Early symptoms can be subtle, so regular screenings are essential, especially for those with risk factors.

What Causes Rectal Cancer?

Rectal cancer causes are linked to a combination of genetic, environmental, and lifestyle factors:

1. Genetic Mutations: Changes in DNA that lead to uncontrolled cell growth.
2. Family History: A higher risk if immediate relatives have had colorectal cancers.
3. Inflammatory Bowel Diseases: Conditions like Crohn’s disease or ulcerative colitis increase susceptibility.
4. Dietary Factors: Diets high in red and processed meats, low in fibre, or lacking fruits and vegetables.
5. Smoking and Alcohol: Long-term use of tobacco and excessive alcohol consumption elevate risk.
6. Obesity: Being overweight is a significant risk factor.
7. Age: Most cases occur in people over 50, though younger adults can also develop it.

Treatment Options for Rectal Cancer

Rectal cancer treatment varies depending on the stage and individual health conditions. Key treatments include:

Rectal Cancer Surgery

Local Excision:

For early-stage rectal cancer, a local excision involves removing the tumour and a small margin of surrounding healthy tissue. This minimally invasive procedure is often performed for tumours that haven’t spread beyond the rectum’s inner lining. It helps preserve rectal function and avoid major surgery.

Resection:

In more advanced cases, surgeons perform a resection, which involves removing the tumour along with part of the rectum and nearby lymph nodes to prevent cancer spread. Depending on the tumour’s location, a low anterior resection (LAR) or an abdominoperineal resection (APR) might be performed. This procedure is vital for ensuring that all cancerous cells are removed.

Colostomy:

In advanced or complex cases, a colostomy may be necessary. This involves creating an opening in the abdomen (stoma) to reroute waste into a colostomy bag. While this can be a life-altering change, it is often a critical step in managing advanced rectal cancer.

Chemotherapy

Chemotherapy uses drugs to destroy cancer cells, either by stopping their growth or preventing them from dividing. For rectal cancer, it is often used:

• Before surgery (neoadjuvant chemotherapy): To shrink tumours, making them easier to remove surgically.
• After surgery (adjuvant chemotherapy): To eliminate any remaining cancer cells and reduce recurrence risk.

It is particularly effective in advanced stages or when the cancer has spread to other organs.

Radiation Therapy

Radiation therapy targets cancer cells in the rectum using high-energy rays or particles. It’s commonly combined with chemotherapy for greater effectiveness.

• Pre-surgical (neoadjuvant): Shrinks tumours, allowing for less invasive surgery.
• Post-surgical (adjuvant): Destroys residual cancer cells in the area.

This treatment is especially useful for cases where the cancer is locally advanced but hasn’t spread to distant organs.

Targeted Therapy

Targeted therapy involves drugs that specifically attack cancer cells while sparing healthy ones, minimising side effects. Drugs like monoclonal antibodies block signals that cancer cells use to grow, or they prevent the formation of new blood vessels that nourish tumours. This personalised approach is most effective in cases where cancer has specific genetic markers.

Immunotherapy

Immunotherapy harnesses the body’s immune system to fight cancer. By either stimulating the immune system or introducing lab-engineered immune components, it enables the body to identify and destroy cancer cells more effectively.

• Checkpoint inhibitors: Block proteins that stop immune cells from attacking cancer cells.
• Indicated Use: Particularly effective in rectal cancers with genetic mutations like microsatellite instability (MSI).

When to See a Doctor?

If you notice symptoms like rectal bleeding, changes in bowel habits, or unexplained weight loss, consult a specialist. You can get an appointment with a trusted oncologist in Bangalore at your nearest SPARSH hospital for expert care and personalised treatment plans.

Conclusion

Rectal cancer is a serious condition, but early detection and treatment significantly improve outcomes. Regular screenings, a healthy diet, and lifestyle changes can lower your risk. If you experience persistent symptoms, don’t hesitate to seek professional help.

Frequently Asked Questions

What is Stage 1 rectal cancer?

Stage 1 cancer is confined to the inner lining of the rectum and has not spread to lymph nodes or distant organs. It is highly treatable with surgery.

What are the first signs of rectal cancer?

Early signs often include rectal bleeding, changes in bowel habits, and persistent abdominal discomfort.

How curable is rectal cancer?

With early diagnosis, rectal cancer is highly curable. Advanced stages may require comprehensive treatment but still have potential for remission.

What is Stage 4 rectal cancer?

Stage 4 indicates that cancer has spread to distant organs, like the liver or lungs. Treatment focuses on managing symptoms and extending life expectancy.