Colorectal Cancer
What is Colorectal Cancer?
Colorectal cancer (CRC) is cancer that starts in the colon or rectum. Most colorectal cancers start as a growth on the inner lining of the colon or rectum, called a polyp. If cancer forms in a polyp, it can grow into the wall of the colon or rectum over time. About 96% of colorectal cancers are adenocarcinomas, which affect the cells that make mucus to lubricate the inside of the colon and rectum (American Cancer Society, 2018).
Risk Factors
Many lifestyle-related factors have been linked to colorectal cancer, such as being overweight or obese, physical inactivity, certain types of diets (low-fiber, high-fat), smoking, and alcohol use. Other risk factors include age (over 45), personal history of colorectal polyps/cancer, personal history of inflammatory intestinal conditions, family history of colorectal cancer/adenomatous polyps, inherited genes/syndromes, racial and ethnic backgrounds, and type 2 diabetes. (American Cancer Society, 2018)
Incidence
According to the National Cancer Institute, colorectal cancer will account for approximately 8.3% of all new cancer cases in the United State in 2020. It is expected that 1,040 new colorectal cancer cases will come from West Virginia alone.
Screening
Should I get screened?
Screening can detect precancerous growths that can be removed, or detect cancer at an early stage when treatment is less extensive and more successful. The ACS recommends that people of average risk of colorectal cancer start regular screening at age 45. Average risk means you do not have a personal or family history of colorectal cancer or certain types of polyps, a personal history of inflammatory intestinal conditions, a confirmed or suspected hereditary colorectal cancer syndrome, or a personal history of radiation exposure to the abdomen or pelvic area. Average-risk individuals who are in good health with a life expectancy of more than 10 years should continue regular screening through the age of 75. If you are between ages 76 and 85, talk with your doctor about your preference, overall health, and prior screening history. Screening is not recommended after the age of 85.
What are my screening options?
There are two types of screenings: stool-based tests and visual (structural) exams. Stool-based tests are less invasive, but must be done more often, and are typically not recommended for high-risk individuals. Visual exams look at the structure of the colon and rectum for abnormal areas. This can be done with a scope inserted into the rectum, or special X-ray tests.
Signs and Symptoms
Colorectal cancer may not cause symptoms right away. Some signs to look for include:
– Change in bowel habits lasting more than a few days (diarrhea, constipation, narrowing of the stool)
– No feeling of bowel relief with bowel movement
– Rectal bleeding (bright red blood) or blood in the stool
– Anemia (low red blood cell counts)
– Persistent abdominal discomfort such as cramps, gas, or pain
– Weakness and fatigue
– Unintended weight loss
While these symptoms could be caused by other conditions, it is important to see your doctor right away so the cause can be found and appropriately treated.
Stool-Based
– Fecal immunochemical test (FIT)
– Guaiac-based fecal occult blood test (gFOBT)
– Stool DNA test (multitargeted/MT-sDNA)
Stages
The stage of the cancer determines how far it has spread, which can lead to knowing how serious it is and how it is best treated. Staging uses the TNM system, which depends on tumor size (T), the spread to nearby lymph nodes (N), and the spread to distant sites (M).
Stage 0
Also known as carcinoma in situ, or intramucosal carcinoma, the cancer has not grown beyond the inner layer (mucosa) of the colon or rectum.
Stage I
The cancer has grown through the muscularis mucosa into the submucosa (T1) or muscularis propria (T2). It has not spread to nearby lymph nodes or distant sites (N0, M0).
Stage II
- IIA – The cancer has grown into the outermost layers of the colon or rectum but has not gone through them (T3). It has not spread to nearby organs, lymph nodes, or distant sites (N0, M0).
- IIB – The cancer has grown through the wall of the colon or rectum but has not grown into nearby tissues or organs (T4a). It has not spread to nearby lymph nodes or to distant sites (N0, M0).
- IIC – The cancer has grown through the wall of the colon or rectum and has grown into/attached to nearby tissues or organs (T4b). It has not spread to nearby lymph nodes or distant sites (N0, M0).
Stage III
- IIIA – One of two scenarios: Scenario 1 is the cancer has grown through the mucosa into the submucosa (T1) and may have grown into the muscularis propria (T2). It has spread to 1-3 nearby lymph nodes (or fat near the lymph nodes) (N1 or N1c). It has not spread to distant sites (M0). Scenario 2 is the cancer has grown into the submucosa (T1). It has spread to 4-6 nearby lymph nodes (N2a). It has not spread to distant sites (M0).
- IIIB – One of three scenarios: Scenario 1 is the cancer has grown into the outermost layers of the colon or rectum (T3) or through the visceral peritoneum (T4a) but has not reached nearby organs. It has spread to 1-3 nearby lymph nodes (or fat near the lymph nodes) (N1a, N1b, or N1c). It has not spread to distant sites (M0). Scenario 2 is the cancer has grown into the muscularis propria (T2) or the outermost layers of the colon or rectum (T3) and has spread to 4-6 nearby lymph nodes (N2a). It has not spread to distant sites. Scenario 3 is the cancer has grown through the mucosa into the submucosa (T1) or the muscularis propria (T2). It has spread to 7 or more nearby lymph nodes (N2b). It has not spread to distant sites (M0).
- IIIC – One of three scenarios: Scenario 1 is the cancer has grown through the wall of the colon or rectum (including the visceral peritoneum) but has not reached nearby organs (T4a). It has spread to 4-6 nearby lymph nodes (N2a). It has not spread to distant sites (M0). Scenario 2 is the cancer has grown into the outermost layers of the colon or rectum (T3) or through the visceral peritoneum (T4a) but has not reached nearby organs. It has spread to 7 or more nearby lymph nodes (N2b). It has not spread to distant sites (M0). Scenario 3 is the cancer has grown through the wall of the colon or rectum and has grown into/attached to nearby tissues or organs (T4b). It has spread to at least 1 nearby lymph node (or fat near the lymph nodes) (N1 or N2). It has not spread to distant sites (M0).
Stage IV
- IVA – The cancer may have grown through the wall of the colon or rectum (any T). It may have spread to nearby lymph nodes (any N). It has spread to 1 distant organ or distant set of lymph nodes but has not spread to distant parts of the peritoneum (M1a).
- IVB – The cancer may have grown through the wall of the colon or rectum (any T). It may have spread to nearby lymph nodes (any N). It has spread to more than 1 distant organ or distant set of lymph nodes but has not spread to distant parts of the peritoneum (M1b).
- IVC – The cancer may have grown through wall of the colon or rectum (any T). It may have spread to nearby lymph nodes (any N). It has spread to distant parts of the peritoneum and may have spread to distant organs or lymph nodes (M1c).
How Our Team Treats Colorectal Cancer
Once a biopsy reveals cancer cells and a PET scan confirms a tumor, your physician may prescribe radiation therapy. Radiation therapy may be used as your primary treatment or in conjunction with surgery or chemotherapy. At the Radiation Oncology Services at Charleston Area Medical Center (CAMC), we offer multiple forms of external beam radiation therapy (EBRT). EBRT is used to treat colorectal cancer non-invasively by delivering thousands of precise, high-energy radiation “beamlets” to the cancer cells. It is a safe and effective treatment for colorectal cancer, damaging cancer cells and making them unable to multiply, while minimizing damage to surrounding healthy tissue. Side effects are usually minimal, with most patients returning to normal daily activities after each treatment. Several factors determine candidacy for radiation therapy treatment including the stage of the cancer, potential side effects, age, and overall health.
Two of the most common forms of EBRT used at CAMC for colorectal cancer are three-dimensional conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT). Both forms use the TrueBeam linear accelerator machine, which moves and rotates around the patient to deliver radiation beamlets from many different angles. The form of radiation treatment used will be determined on an individual basis by the physician. 3D-CRT is typically used if the cancer covers a wider area, while IMRT is used for more precise doses or if the tumor is close to critical structures. For more information, contact us to schedule a consultation with one of our qualified radiation oncologists.
Key Advantages of Radiation Therapy for Colorectal Cancer
- Few to minimal side effects
- Non-invasive and requires no sedation
- Outpatient procedure lasting a total of 15-20 minutes daily
- Minimal recovery time
- Most patients return to normal activities following treatment sessions
Speak with one of our dedicated Team Members about how we can help today.