How is Colon Cancer Diagnosed?


Your doctor will recommend exams and tests if you have symptoms or if a colon cancer screening test shows unusual signs.

  • Medical history and physical exam
  • Blood tests
  • Diagnostic colonoscopy. Your gastroenterologist will look at your colon and rectum with a colonoscope. An unusual tissue sample is taken for biopsy, and polyps are removed and examined. Nearly all colonoscopies in the United States are done under anesthesia.
  • Biopsy. A small piece of suspected tissue and polyps found during a colonoscopy are removed and examined for cancer cells at the laboratory. If cancer cells are found, further tests will be ordered to create an effective treatment plan.
  • Imaging tests. Your care team may recommend CT, X-rays, and MRI scans to closely examine tumors inside the colon to determine how far cancer has progressed and whether it has spread to other organs.

Cancer is shown in a section of the descending colon

Screening for colon cancer

Screenings are tests that detect cancer early before signs and symptoms develop. Doctors recommend that adults aged 45 and older get screened for colorectal cancer. Talk to your doctor about which screening test is right for you. Also talk to your doctor about when to begin screening if you’re under 45 with an increased risk of developing colorectal cancer.

  • Some colorectal screening tests can find and remove polyps in the colon or rectum to lower the risk of developing cancer. Colonoscopy is a standard outpatient procedure used to check for colorectal polyps and cancer. During your colonoscopy, your colorectal area will be examined. Any suspicious tissue will be examined for signs of cancer

If you are diagnosed with colon cancer, our team of experts at NewYork-Presbyterian will be available to meet with you to discuss your diagnosis. Your team will then recommend the best treatment options based upon the type, location, and cancer stage. Your age and physical health will also be taken into consideration.

How is Colon Cancer Treated?


Treatment for colon cancer usually involves surgery to remove any cancerous tumors. Your doctors will decide on your treatment plan based on your situation, tumor location, disease progression, and other factors. Chemotherapy and radiation therapy may also be recommended.


Surgery is the most common treatment for all stages of colon cancer. During surgery, your doctor will remove any cancerous tumors.

  • Local excision - If the tumor is small your doctor may remove it with a tool that is inserted into the colon through the rectum
  • Partial colectomy - If the tumor is larger, your doctor will remove it along with a small nearby section of healthy tissue and then sew the healthy parts of the colon together.
  • Colostomy - An opening is created (stoma) to collect body waste into a bag located outside the stoma. The colostomy may be needed only until the colon has healed, but may be permanent.
  • Surgery to remove cancer that has spread - If the cancer has spread, for example, to the liver, your doctor may recommend surgery to remove cancerous tumors, but this depends upon the size and number of lesions in the liver.

After the surgery, you may have chemotherapy to kill any remaining cancer cells.


Chemotherapy is a drug treatment to stop the growth of cancer cells and is given as an infusion through a vein (common) or pill form, and typically requires a combination of anticancer drugs. Chemotherapy often follows surgery to make sure cancer cells that remain in the body are destroyed. In the case of colon cancer, that occurs in stage three.

Radiation therapy

Radiation therapy is a cancer treatment that uses high-energy beams, X-rays, or other types of radiation to kill cancer cells or prevent them from growing. It may be used with chemotherapy before surgery to shrink a large tumor before surgery.

Targeted therapy

Targeted Therapy is a type of cancer treatment that is designed to recognize specific molecules (proteins) that control how cancer cells grow and divide. Most targeted therapies are either small-molecule drugs or monoclonal antibodies. Targeted drugs are usually combined with chemotherapy and are used to treat people with advanced colon cancer.


Immunotherapy is a treatment that uses your immune system to fight cancer. Immunotherapy is a type of biological therapy used to restore and boost your natural immune system can destroy cancer cells better.



A pain in the abdominal area, cramps, and bloating (fullness).

Blood in the stool appears dark brown or black, and there may be bright red blood bleeding from the rectum.

Colon cancer is quite common after breast, prostate, and lung cancers. The risk is 5% for women and 6% for men.

Colon cancer most often spreads to the liver, but it can also spread to the lungs, brain, peritoneum (the lining of the abdominal cavity), and lymph nodes.

The overall 5-year survival rate (the chance that you will live for at least five years) is 68%, but it depends on how far the cancer has spread. If there is no sign that the cancer has spread outside of the colon or rectum the 5-year survival rate is 91% but the rate decreases if the cancer has spread.

Get Care

Trust NewYork-Presbyterian for Colon Cancer Treatment

At NewYork-Presbyterian, our colorectal cancer specialists treat people with all stages of colon cancer. We offer full colon cancer care, from diagnosis through treatment, counseling for our oncology patients and their caregivers, and palliative care.

NewYork-Presbyterian holds multi-disciplinary clinics and tumor boards where specialists from different treatment modalities come together to customize your treatment needs. Contact us to schedule an appointment.