by Dr Shabnam Bashir
Colorectal cancer carries a significant behavioural component. Prevention is not only possible, but also often within reach.
Colorectal cancer originates in the colon or rectum, both components of the large intestine. It has become one of the most prevalent forms of cancer across the globe. Among men, it is the third most frequently diagnosed cancer, while in women it ranks second. Each year, approximately 1.5 million new cases are reported worldwide, accounting for nearly 11 per cent of all cancer diagnoses. In ten countries, it is the most commonly diagnosed malignancy in men.
In India, the annual number of new cases hovers around 75,000. A study conducted at the Sher-i-Kashmir Institute of Medical Sciences between 2014 and 2016 found that colorectal cancer was most prevalent among individuals aged between 56 and 65, making up 25 percent of the cases. Strikingly, around 20 per cent of those diagnosed were under the age of 35. At the time of diagnosis, half the cases were already at Stage III.
The global burden of this disease continues to rise. Projections suggest that by 2030, the number of new cases will surge by 60 per cent, surpassing 2.2 million annually, with deaths approaching 1.1 million each year. Survival rates remain tied to the stage at which the cancer is detected. For Stage I colon cancer, the five-year relative survival rate reaches up to 92 per cent. In contrast, for Stage IV, this figure drops drastically to 12 per cent. These statistics underscore the need for effective global screening programmes.
In certain regions, the disease poses unique challenges. Early onset cases are becoming more common. Many patients present at a late stage. The prognosis is often poor, shaped by unfavourable histopathological findings. There is limited awareness, a lack of standardised treatment protocols, and inadequate access to healthcare.
Despite these challenges, there is cause for cautious optimism. An estimated 90 per cent of colorectal cancers are preventable.
Colorectal cancer often presents subtly. A shift in bowel habits may be the earliest indication. Some experience a persistent sense of incomplete evacuation or notice blood in the stool. For others, the stools appear narrower than usual. Abdominal bloating, a sensation of fullness, or cramping pain may follow. These symptoms are frequently joined by unintended weight loss, iron deficiency anaemia, generalised fatigue, and physical weakness. In rare cases, particularly in rectosigmoid cancers, haemorrhoids may emerge as the first sign.
Colorectal cancer carries a significant behavioural component. Prevention is not only possible, it is often within reach. Certain dietary and lifestyle patterns appear to foster intestinal inflammation. These habits can alter the gut’s microbial population in a way that activates the immune system, facilitating the growth of polyps and their eventual transformation into malignancy.
Lifestyle changes hold the potential to halt this progression. Regular physical activity, a diet anchored in fruits and plant-based foods, and the maintenance of a healthy body weight are all associated with reduced risk. Early screening and genetic testing also form part of a preventive strategy. Calcium and vitamin D have demonstrated protective effects. Fibre, abundant in vegetables, fruits, and whole grains, speeds the passage of stool, thereby reducing the colon’s exposure to potential carcinogens. It may also confer additional benefits through its antioxidant properties.
Other foods with possible protective roles include garlic, magnesium, fish, and vitamin B6. Avoidance of tobacco and alcohol is strongly advised. Long-term use of non-steroidal anti-inflammatory drugs, particularly aspirin, has been shown to reduce both the incidence and aggressiveness of tumours, improving survival. However, these drugs carry a risk of gastrointestinal bleeding and are not recommended for the general population. The United States Preventive Services Task Force does, however, support low-dose aspirin for individuals over 50 with an elevated risk of cardiovascular disease or colorectal cancer.
Screening plays a vital role in reducing mortality, particularly in high-income countries. The condition is especially suitable for population-based screening due to several factors. Its high global incidence, the sharp rise in treatment costs as the disease advances, and the importance of early detection in preserving the rectum in lower cancers all point to the value of early intervention. Its relatively predictable progression from adenoma to carcinoma spanning at least five to ten years offers a window of opportunity. Adenomas and early-stage cancers are frequently amenable to removal via endoscopy. Such interventions can significantly reduce mortality.
A range of screening options exists. Colonoscopy remains the gold standard. CT colonography offers a non-invasive alternative. Biomarkers such as the guaiac faecal occult blood test (gFOBT) and the faecal immunochemical test (FIT) provide additional tools, with FIT offering greater sensitivity. Systematic reviews and meta-analyses have shown that biennial FIT screening can lower mortality by 12 per cent over fifteen years when compared with no screening at all. Multitarget stool DNA tests show higher sensitivity for detecting cancer and advanced adenomas, though they are less specific, and their accuracy diminishes with age.
All these screening modalities are currently available in Kashmir.
Diagnosis begins with a physical examination. A digital rectal examination remains a standard step, often followed by proctoscopy or flexible sigmoidoscopy. Colonoscopy, often combined with biopsies and therapeutic removal of polyps, remains the most definitive method. Other options include CT colonography, capsule endoscopy, and carcinoembryonic antigen testing for prognostication.
Surgical removal remains the cornerstone of treatment. Depending on tumour size and location, surgeons may remove part of the large intestine or, in some cases, the rectum itself. This can involve the creation of a stoma, an intestinal opening on the abdominal wall, for the passage of stool. These procedures may be temporary or permanent. Some surgeries preserve the sphincter; others require more extensive resection, occasionally including surrounding organs. These operations may be performed using open surgery, laparoscopy, or robotic-assisted techniques.
Other treatment modalities include chemotherapy, which uses drugs to kill cancer cells, and radiation therapy, which delivers targeted beams to destroy malignant tissue. Targeted therapy tailors treatment based on the specific properties of the tumour, while immunotherapy, particularly for patients with high microsatellite instability or mismatch repair deficiencies, offers a more personalised approach. In some cases, a “watch and wait” strategy is adopted, depending on tumour response and clinical judgement.
(The author is a senior consultant in breast and colorectal cancer surgery, trained at Tata Memorial Hospital, Mumbai, and in the United States. She is the first female surgeon from Kashmir to be trained in robotic surgery. Dr Bashir is the Founder and Director of the Centre for Breast and Colorectal Cancers and Non-Cancer Disorders (CBCCD), Kashmir. She serves on the Executive Committee of the Association of Colon and Rectal Surgeons of India and is a visiting faculty member at IIT Kanpur’s Gangwal Medtech School. Ideas are personal.)
