4 types of Colon Cancer: Symptoms, causes, and treatment

Colon cancer, also known as colorectal cancer, is one of the most frequent and aggressive cancers. According to the WHO, it accounts for about 10% of all cancers diagnosed, and deaths worldwide. Many colon cancers are curable if caught early; however, certain types are quite aggressive and have a higher mortality rate. Understanding these types and their development is of utmost importance regarding prevention, and the possibility of early detection.

Adenocarcinoma: This is the most common type of colon cancer, accounting for about 95%. These slowly arise from glandular epithelial cells lining the inner surface of the colon. The problem with this cancer is that it starts very slowly, often beginning as benign and thus being called adenomatous polyps. Over several years, genetic mutations accumulate, eventually transforming these polyps into malignant tumors.
Key stages:
The mutation commonly represents the initial step and sets off the development of polyps.
Stimulates the growth and proliferation of these polyps.
A tumor suppressor gene mutation that allows cells to become fully cancerous.

Other accelerating factors in the path from a single polyp to malignancy include low-fiber diet, smoking, and chronic inflammation. It is important to realize that adenocarcinomas are dangerous because early stages do not cause symptoms, and when detected, the cancer may have already invaded the colon, lymph nodes, or distant organs like the liver or lungs.

Colorectal mucinous adenocarcinoma is a unique clinicopathological subtype in colorectal cancer. Mucinous colorectal adenocarcinoma is found in 10%–20% of CRC patients and occurs more commonly in females and younger patients. This is characterized by excessive production of mucin gel-like substance that infiltrates the tissues over time. Tumours that are rich in mucin are often very invasive and difficult to detect on routine screening.

Mucinous adenocarcinomas frequently have a poorer prognosis compared to more typical adenocarcinomas. The tumors are more chemoresistant, and metastasis to lymph nodes or the peritoneal cavity occurs much earlier and diminishes survival.

It is an aggressive type of cancer that accounts for less than 1% of colon cancers. The name "signet ring", describes the appearance of cancer cells when viewed under a microscope, where the nucleus is pushed to the side by a large mucin droplet. Unlike adenocarcinomas, the small droplet further develops differently and forms discrete polyps; signet ring cell carcinoma grows diffusely, infiltrating the colon wall. Because the tumors do not always form a noticeable lump, early detection in this case is difficult, and it may remain hidden for decades until a routine colonoscopy is done.

It is a highly fatal cancer because of its aggressive nature and late diagnosis. It spreads very fast through lymph nodes and other organs, making conventional chemotherapy less effective.

Similar to the signet ring cell carcinoma, these neuroendocrine tumors of the colon are also infrequent but can be highly malignant, particularly with the high-grade NEC's. These cancers arise from neuroendocrine cells that secrete hormones and peptides and may present as slow-growing or highly aggressive form of tumors. Sometimes these tumors produce hormones that cause paraneoplastic syndromes and thereby creating more complications because neuroendocrine cancer usually does not present symptomatically until at a late stage, they are often diagnosed at a later stage, which decreases the likelihood of successful treatment.

Keep colon healthy with the right diet and no alcohol

A healthy colon can be maintained naturally through daily habits rather than cleanses. Eating plenty of fiber-rich foods, staying well hydrated, and including probiotics support smooth digestion. Regular exercise and limiting processed foods also help. Avoid unnecessary detox products, and prioritize routine screenings to keep your colon functioning well and prevent long-term problems.

Colon cancer symptoms can include persistent changes in bowel habits, blood in the stool, abdominal pain or cramping, unexplained weight loss, fatigue, and feeling that the bowel doesn’t empty completely. Stools may become narrow or dark. These signs can overlap with other conditions, so persistent symptoms should be evaluated by a healthcare professional.