Polyps are tissue growths, often in the colon. While many are benign, some can become cancerous or already contain cancer cells. Medical evaluation of identified polyps is important due to this potential.
Confirming the Malignancy
Once a polyp is removed, typically during a colonoscopy, it is sent to a pathology laboratory for examination. A pathologist studies the tissue under a microscope to determine if it contains cancerous cells and their nature.
Pathologists look for specific cellular changes, such as dysplasia, which is abnormal cell growth. Dysplasia ranges from low-grade to high-grade, with high-grade indicating more abnormal cells. If cancer cells are confined to the polyp’s top layers or colon lining, this is high-grade dysplasia, intramucosal carcinoma, or carcinoma in situ. This early cancer cannot yet spread to other body parts.
If cancer cells penetrate beyond the muscularis mucosae into the submucosa, it is invasive adenocarcinoma. The pathology report details tumor differentiation, describing how much cancer cells resemble normal cells. Poorly differentiated cancers tend to grow and spread more quickly. The presence of vascular, lymphatic, or lymphovascular invasion (cancer cells in blood or lymph vessels) indicates a higher risk of spread.
Determining the Cancer’s Extent
After a polyp is confirmed cancerous, further evaluation, known as staging, determines the cancer’s extent. This assesses if the cancer has spread beyond the original polyp and to which areas. Staging guides the appropriate treatment plan.
Healthcare providers use various diagnostic tests to determine spread. Imaging scans like CT, MRI, and PET scans produce detailed images of internal organs. These can reveal if cancer has spread to nearby lymph nodes or distant organs like the liver or lungs.
Blood tests also play a role. Tests for tumor markers like carcinoembryonic antigen (CEA) help monitor cancer’s response to treatment or detect recurrence. A complete blood count can check for anemia, which might indicate bleeding from colon cancer.
Treatment Approaches
Treatment for a cancerous polyp depends on pathology findings and cancer stage. If cancer is early and confined within the polyp, polypectomy (surgical removal during a colonoscopy) may be sufficient. For larger or hard-to-reach polyps, local excision or minimally invasive laparoscopic surgery may remove the polyp and surrounding tissue.
When cancer has grown deeper into the colon wall or spread to nearby lymph nodes, more extensive surgery is required. A partial colectomy removes the cancerous colon section, healthy tissue, and nearby lymph nodes. The remaining colon sections are then reconnected.
Beyond surgery, adjunctive therapies like chemotherapy and radiation therapy may be used. Chemotherapy uses medicines to kill cancer cells throughout the body. It is often given after surgery to eliminate remaining cells and reduce recurrence risk, or before surgery to shrink tumors.
Radiation therapy uses high-energy beams to destroy cancer cells. It is more common for rectal cancer but also applies to colon cancer. It can be administered before surgery to shrink tumors, or after surgery to target residual cancer cells. Radiation therapy can also alleviate symptoms like pain or bleeding. Chemotherapy and radiation therapy are often combined in chemoradiation, which enhances their effectiveness.
Life After Treatment and Ongoing Care
After initial treatment, ongoing care and surveillance are important to monitor for recurrence and ensure long-term health. A structured follow-up plan is necessary due to the risk of cancer returning. This plan involves regular medical history reviews, physical examinations, and blood tests, including tumor markers like CEA.
Regular surveillance colonoscopies are a cornerstone of post-treatment care. For patients with curative surgery, a colonoscopy is often recommended one year after the procedure. Subsequent colonoscopies are scheduled at intervals of three years, then five years, depending on initial cancer stage and new findings.
Imaging tests, such as CT scans of the chest, abdomen, and pelvis, are performed periodically to check for recurrence or spread, especially for stage II or III colon cancer.
Managing potential treatment side effects is another aspect of ongoing care. Patients may experience fatigue, bowel changes, nausea, or peripheral neuropathy, and healthcare teams provide strategies and medications to alleviate these. Adopting a healthy lifestyle, including diet, weight management, and exercise, supports overall well-being and recovery.