Diagnosing Rectal Cancer
Rectal cancer is a type of cancer that originates in the rectum, which is the final part of the large intestine. It is a form of colorectal cancer. Specialists who may be involved in diagnosing rectal cancer include:
- Gastroenterologists: These doctors specialize in diagnosing and treating diseases of the digestive system, including rectal cancer.
- Oncologists: Oncologists are doctors who specialize in treating cancer. They may be involved in confirming the diagnosis and developing a treatment plan.
- Surgeons: Surgeons play a crucial role in treating rectal cancer through surgical interventions. They may be involved in diagnosing the extent of the disease during surgical procedures.
To diagnose rectal cancer, doctors may use several examinations, screening tests, and procedures. These include:
- Personal and family medical history: Doctors will ask about your personal and family medical history to understand any potential risk factors for rectal cancer.
- Physical exam: A physical exam allows the doctor to assess your overall health and check for any signs or symptoms of rectal cancer. During the physical exam, the doctor may also perform a digital rectal exam (DRE) by inserting a gloved finger into the rectum to feel for any lumps or abnormalities.
- Colonoscopy: A colonoscopy is a procedure in which a doctor uses a thin tube with a light and camera at the end to examine the inside of your rectum and colon. This procedure helps visualize any abnormal growths, such as polyps or tumors, and allows the doctor to take tissue samples (biopsy) for further examination.
- Biopsy: During a colonoscopy, the doctor can collect tissue samples from any suspicious areas in the rectum. These samples are then examined under a microscope to determine if they are cancerous.
- Tumor marker tests: Other tests, such as immunohistochemistry and carcinoembryonic antigen (CEA) assay, can look for specific antigens or chemicals in body tissues or blood that may indicate the presence of rectal cancer.
These examinations, screening tests, and procedures help confirm a diagnosis of rectal cancer by identifying abnormal growths in the rectum and determining if they are cancerous. The biopsy provides definitive evidence of cancer cells in the tissue samples.
To determine the type, severity, or stage of rectal cancer, additional examinations, tests, or procedures may be done. These include imaging tests, which help visualize the extent of cancer and identify any spread to other parts of the body. Imaging tests include:
- Endorectal ultrasound: This test uses a probe inserted into the rectum to produce images (sonograms) of the rectum and surrounding area.
- CT scan or PET scan: These scans provide detailed images that help assess the extent of cancer in the rectum, colon, and other organs.
- MRI: Magnetic resonance imaging can help determine the stage of rectal cancer by providing detailed images of the tumor and nearby structures.
These additional examinations and tests help identify factors or indicators related to the type (e.g., adenocarcinoma), severity (e.g., tumor size), or stage (e.g., whether it has spread to lymph nodes or other organs) of rectal cancer. This information is crucial for developing an appropriate treatment plan tailored to each individual's situation.