As research evolves and we know more about rectal cancer, more methods for screening and diagnosis become available. If you need to be screened for rectal cancer, there are several ways and a diagnosis can be determined from a variety of those methods as well.
Rectal cancer screening can help find cancer at its earliest stage when the chances for successful treatment and optimal outcomes are greatest. Screening is recommended to start at age 45.
People at an increased risk for colorectal cancer should start screening earlier under a physician's direction; those at increased risk include those with a family history of colorectal cancer, those with a known hereditary colorectal cancer syndrome and those with inflammatory bowel disease. The timing of when to start screening will vary by the individual. Anyone with symptoms should also be evaluated and may need to have diagnostic testing to rule out a cause.
The OSUCCC – James is home to some of the foremost rectal cancer experts in the United States. This team is working together across disciplines to develop new screening and treatment options to further increase early detection and the rectal cancer survival rate.
Rectal cancer early detection
Early detection of rectal cancer is a critical step toward more positive outcomes. As mentioned, the OSUCCC – James recommends that you’re screened for rectal cancer starting at age 45. Those at a higher risk for developing rectal cancer (certain medical or hereditary conditions listed above) should be screened earlier or if symptoms develop as soon as possible.
Screening tests for rectal cancer
With early detection being an important part of diagnoses and long-term positive prognoses, you should also understand the different screening options for rectal cancer.
Virtual or physical colonoscopy
Colonoscopies can be done physically or virtually, both using modern technology. The physical colonoscopy screens for rectal cancer with a flexible tube with a small camera on it where a specially trained physician can identify any polyps or abnormalities in your colon or rectum. Polyps that have not yet become cancers can usually be removed at the same time. A flexible sigmoidoscope can be used to examine the rectum and distal colon and thus can screen specifically for rectal cancer.
A virtual colonoscopy is often called a CT colonoscopy. In this procedure, the cancer specialist takes X-ray images of the colon and rectum using a scanner that rotates around your body. A connected computer and software produce detailed images, often in 3D, to reveal polyps or signs of cancer.
Both a traditional (physical) colonoscopy and virtual colonoscopy require a day of preparation before the procedure can be performed. Your cancer specialist will provide all necessary information before the colonoscopy is scheduled. Not everyone is a candidate for a virtual colonoscopy, so your doctor will determine the right test for you.
Sigmoidoscopy
Using a thin, flexible tube (called a sigmoidoscope), your cancer specialist can examine the rectum and detect any abnormalities or signs of cancer. This device contains a camera on one end that looks for polyps or tumors, and a tool on the other end that can aid in removing polyps or tissue.
Fecal occult blood test
A fecal occult blood test for rectal cancer involves a stool sample for occult blood. Occult blood is blood that can only be seen when viewed under a microscope. This type of rectal screening is conducted by you at home, using a special card that contains instructions from your cancer physician or a lab.
Fecal immunochemical blood test
A fecal immunochemical blood test for rectal cancer is a newer development in screening. This test identifies blood in your stool using a chemical that reacts to a protein found in red blood cells and can be done without dietary restrictions (which are typically required with a fecal occult blood test).
Genetic testing
If your family or genetic history indicates you may be at a higher risk of developing rectal cancer, your physician may recommend a genetic test. This can include samples of your blood, cheek cells (collected in mouthwash) or a stool sample; your doctor will use the sample to look for changes in your genes that could indicate a risk of cancer.
How rectal cancer is diagnosed
Once your cancer specialist or physician has conducted screening for rectal cancer, they will use that information to determine next steps - including a potential diagnosis. Your doctor may recommend additional tests coupled with a complete physical examination.
Many tests used to screen for rectal cancer are also used in the diagnosis stage of the process.
Colonoscopy biopsy and results
Your colonoscopy, whether conducted virtually (CT) or in the traditional manner, can help your doctor determine if polyps or cancer are developing in the rectum. During a traditional colonoscopy, your doctor can take tissue samples (biopsy) and remove any potentially harmful polyps they may see. If polyps or cancer are detected during a CT colonoscopy, a traditional colonoscopy is required to take a tissue biopsy and/or remove it.
Once the biopsy is completed, this will allow the doctor to determine if you have rectal cancer. Rectal tissue is collected and then will be examined by an OSUCCC – James pathologist, who will identify if there are any signs of cancer.
Blood tests for cancer or anemia
If you have anemia, colorectal cancer could be a cause, and your physician may recommend a colonoscopy to further evaluate it.
What types of tests are used to determine the stage of my rectal cancer?
If you’re diagnosed with cancer, the next step for your doctor is to determine its stage. “Stage” or “staging” refers to how advanced your rectal cancer has become at the point of diagnosis.
The staging of your rectal cancer will also help when developing a plan to treat it.
Here’s how the experts at the OSUCCC – James use different technologies to stage your cancer and start planning for treatment.
Rectal cancer imaging exams
CT (computed tomography) scan
This X-ray imaging takes photos of the affected area from different angles and positions, allowing your doctor to determine if the cancer is contained within your rectum or has spread to other parts of the body. CT of the chest and abdomen are routinely done for rectal cancer staging.
Magnetic resonance imaging (MRI)
Commonly referred to as an MRI, this type of imaging provides your doctor with high-resolution, detailed images of the body. It typically gives your doctor more information regarding rectal cancer tumor size and any signs of progression. It evaluates how deep the rectal cancer has gone into the wall of the rectum, the relationship to other organs in the pelvis and evaluates the lymph nodes around the rectum to determine if it has spread.
Endorectal ultrasound
An endorectal ultrasound is a type of analysis for rectal cancer that uses sound rays (rather than X-ray imaging) to look for the potential spread of cancer.
X-ray imaging of the chest
Your rectal cancer specialist will use X-ray imaging of your chest to see if cancer has spread to the lungs.
Analysis of rectal cancer tumor markers
Done through blood testing, this test involves examination of substances made by tumor cells, tissues and organs in your body.
If you have received a rectal cancer diagnosis, or if you want a second opinion or just want to speak to a rectal cancer specialist, we are here to help you. Call 800-293-5066 to make an appointment.
Related Resources
Rectal Cancer Prevention and Risk Factors
Rectal Cancer Treatment
Rectal Cancer Treatment Team
Rectal Cancer Stages
Colorectal Cancer Rates on the Rise Among Younger Patients