Most colorectal cancers occur in people in their 60s and 70s, though colorectal cancer in young adults is on the rise. Colorectal cancer is now the top cause of cancer death in people under 50.

Researchers are looking into the reasons for this trend. Lifestyle factors (obesity and lack of exercise) may play a role.

You are more likely to develop colorectal cancer if you are overweight or obese and don’t exercise. Drinking alcohol, smoking or eating a diet high in red meats or processed meats can also increase your risk.

Your risk of colorectal cancer increases if you or a close relative has had colorectal polyps. You’re also more likely to develop colorectal cancer if you have inflammatory bowel disease (Crohn’s disease or ulcerative colitis) that goes untreated.

Some diseases passed down in families (inherited syndromes) may make colorectal cancer more likely. Talk to your physician to learn more about your risk.  

We may analyze a sample of your stool to check for blood or changes to DNA. At-home stool test kits are available. Talk to your physician about your risk level and whether at-home testing is right for you.

A sigmoidoscopy is similar to a colonoscopy, but it’s slightly less invasive. The test uses an endoscope to examine only the lower part of your colon. You don’t need sedation for a sigmoidoscopy.

This test uses CT scans to create detailed images of your colon and rectum. Since it's noninvasive and doesn’t use an endoscope, we may recommend it for those who can’t have sedation for a traditional colonoscopy.

A colonoscopy is the most common screening and diagnostic test for colorectal polyps and cancer. Your specialist uses an endoscope (flexible tube with a light and video camera on one end) to examine your entire colon and rectum. You're typically asleep (sedated) during a colonoscopy.

We use the latest blood tests to detect substances in your blood that could indicate cancer (biomarkers). A carcinoembryonic antigen assay checks for high levels of certain proteins in your blood. We also do tests to check your blood for circulating DNA fragments released by tumors.

A transrectal ultrasound is a quick test to examine the rectum, take tissue samples for biopsy and stage rectum cancer. Staging means finding out how much cancer is in your body, and where it is. We insert a small probe (device about the size of a finger) into your rectum. Sound waves from the probe produce detailed images of your rectum on a computer screen.

We may do an MRI or PET scan of other areas of your body to find out if cancer has spread from your colon to your liver, lungs, brain or lymph nodes (clusters of cells that are part of your body’s immune system).

This test is the only way to confirm a colorectal cancer diagnosis. During a colonoscopy or sigmoidoscopy, we take a small tissue sample from your tumor or polyp. A pathologist examines the sample under a microscope to check for signs of cancer.

Surgery is the most common treatment for colorectal cancers. Our skilled specialists typically remove polyps or cancer using procedures called resections.

We can almost always remove early-stage cancers and polyps with endoscopic or laparoscopic/robotic techniques. These procedures are minimally invasive (no large incisions in your abdomen), so you recover faster and with less pain.

Whenever possible, we try to avoid a permanent ostomy if we need to remove part or all of your rectum or colon. If you do need a temporary ostomy, our surgeons have extensive experience in ostomy reversal after you’ve healed from your initial surgery.

We implant a stent (hollow, mesh tube) in your colon to open areas of your bowel blocked by tumors. A stent can delay the need for immediate emergency colorectal surgery and allow you to have a planned operation laparoscopically/ robotically without need for an ostomy.

We may use radiofrequency ablation to treat small tumors that have spread to your liver from your colon or rectum. During this minimally invasive procedure, we use a needle to deliver an electric current directly to the tumor. Heat from the current kills cancer cells.

When possible, we remove tumors and diseased tissue while leaving anal sphincter muscles intact. These muscles help you have bowel movements. UC Davis Comprehensive Cancer Center is among only a few programs in Northern California to offer sphincter-sparing colorectal surgery.

We have the ability to use multiple transanal techniques, including transanal endoscopic microsurgery (TEM), transanal minimally invasive surgery (TAMIS) and robotic TAMIS to remove rectal tumors through your anus. This minimally invasive technique is an alternative to major abdominal surgery that can be used to treat some tumors.

Radiation therapy uses high-energy radiation to destroy tumors. We may use radiation therapy before surgery to shrink tumors (neoadjuvant therapy), making them easier to remove. Used after surgery, radiation can destroy any remaining cancer cells (adjuvant therapy).

Radiation therapy is especially common for rectum cancer treatment because this cancer is more likely to return in the same location. Our radiation oncologists often recommend chemoradiation (a combination of radiation and chemotherapy) before surgery to reduce the risk of reoccurrence. It can also reduce the need for a permanent colostomy.

Chemotherapy uses drugs to destroy cancer cells. You may receive chemotherapy before or after surgery for colorectal cancer. If you aren’t a candidate for surgery due to your age, health or stage of cancer, chemotherapy is an alternative treatment.

We may recommend transarterial chemoembolization (a type of chemotherapy) if colorectal cancer has spread to your liver. In this procedure, we insert a catheter into the main artery supplying blood to your liver to deliver strong doses of chemotherapeutic drugs directly to liver tumors. The drugs also work to partially block the artery, so tumors do not receive the blood they need to grow.

Targeted therapy works on specific proteins and genes in different types of tumors. These drugs target the parts of cancer cells that allow them to grow and divide. We may recommend targeted therapy for colorectal cancer in combination with other treatments.