Colorectal cancer


What is colorectal cancer?

Colorectal cancer is the 2nd most common cancer in the United States. This is astonishing since colorectal cancer is a potentially preventable disease. The majority of colon and rectal cancers begin as a polyp. As the polyp grows, the cells change to develop into cancer. This is why colonoscopy is such an important tool in the prevention of colorectal cancer. Using colonoscopy, your physician can detect pre-malignant polyps and remove them in order to prevent cancer.

Who is at risk?

Although colorectal cancer can occur at any age, most individuals are over the age of 40, and the risk of cancer increases with age. Other risk factors include:

  • Family history of colorectal cancer or polyps
  • African American descent
  • Personal history of polyps
  • Personal history of cancers of other organs especially uterus, ovaries, or breast
  • Inflammatory bowel disease (IBD) including ulcerative colitis (UC) or Crohn’s disease (CD)

What are the symptoms of colorectal cancer?

Early cancers and polyps generally do not cause symptoms. This is why early screening and prevention is so important. When symptoms do develop, this is usually a sign of a larger cancer. The most common symptoms are rectal bleeding and changes in bowel habits such as constipation, diarrhea or a change in the caliber of stools (pencil thin stools). Abdominal pain, nausea, vomiting, and weight loss may indicate more advanced disease.

Can colorectal cancer be prevented?

Colonoscopy is the best tool for screening and prevention of colorectal cancer. Cancer can be prevented by detection and removal of small pre-cancerous polyps at the time of your colonoscopy. When you are found to have polyps, the chance of future cancer increases. Therefore it is recommended that you have repeat colonoscopies every 3 – 5 years instead of every 10 years. Although it is not definitely proven, there is some evidence that a high fiber, low fat diet can prevent colorectal cancer. Early detection is key! Do not put off your colonoscopy. If you notice any change in your bowel habits or rectal bleeding, make an appointment for a private consultation with Dr. Zaghiyan in her office in Los Angeles. See below to find out when you should be screened for colorectal cancer even if you have no symptoms.

When should you be screened for colorectal cancer?

All individuals who are average risk and not African American should have a screening colonoscopy beginning age 50, then every 10 years if no cancers or polyps are found.

African Americans have a higher risk of colorectal cancer. A screening colonoscopy is recommended beginning age 45 then every 10 years if no polyps or cancers are found.

Family history of colorectal cancer or polyps suggests a higher risk of colorectal cancer. Individuals with a family history of colorectal cancer should have a colonoscopy at age 40 or 10 years before the youngest affected relative.

Cancer in several close relatives may suggest your family carries a hereditary cancer syndrome. Individuals with colorectal cancer or various other cancers such as uterine or ovarian cancer in several close relatives, especially if cancers occurred at a young age should have genetic counseling and potentially genetic testing to exclude the possibility of inherited forms of colorectal cancer such as hereditary non-polyposis colorectal cancer (HNPCC) or familial adenomatous polyposis (FAP). It may be recommended that colon cancer screening begin in the teens’ or 20’s for families who are at risk for one of these inherited cancer syndromes.

Polyps detected at the time of colonoscopy may put you at risk for developing new polyps or cancer. Individuals who have a polyp detected should have repeat colonoscopies every 3 to 5 years.

Inflammatory bowel disease (IBD) such as ulcerative colitis (UC) or Crohn’s disease (CD) may put you at higher risk of developing colorectal cancer. Individuals with a diagnosis of UC or CD with severe inflammation of the colon or rectum should have a colonoscopy with biopsies 8 years after initial diagnosis then every 2 years.

Women with a personal history of breast, ovarian or uterine cancer may have a higher risk of colon cancer. These women should have a colonoscopy starting age 40 and every 5 years.


How is colon cancer treated?

The treatments for colon cancer and rectal cancer are somewhat different. After you are diagnosed with colon cancer, your physicians may order several tests including blood (CEA level) and imaging tests (typically CT scan or PET scan of your abdomen and pelvis). If your cancer appears to be early stage, then surgery is the next step. This involves removal of the involved segment of colon along with the mesentery containing the lymph nodes and reconnection of the bowel. In most cases, this can be accomplished by minimally invasive surgery such as laparoscopy or robotic-assisted surgery. In some patients, depending on your general overall condition, traditional open surgery may be necessary. The pathologist will then evaluate the tumor to determine the stage. This process can take 1 week or longer. In most patients with stage I or II cancer (no lymph node involvement), treatment ends with surgery (i.e. no chemotherapy). In some cases, several other findings on the pathology specimen may prompt your physicians to recommend chemotherapy even if your lymph nodes are negative. For cancers that are involving lymph nodes or spread to other organs, chemotherapy is generally recommended before surgery, after surgery, or as the sole treatment depending on your particular condition. Dr. Zaghiyan will discuss these options with you during your office consultation.

How is rectal cancer treated?

Treatment of rectal cancer is largely dependent on how deep the tumor has penetrated into the rectal wall and it’s relationship to the anal sphincters. After you have been diagnosed with rectal cancer, your doctors may order several test including a CEA blood level, CT scan or PET scan of your chest, abdomen and pelvis to assess for metastasis of the tumor. During your office examination, Dr. Zaghiyan may perform a digital rectal exam and proctoscopy to assess your sphincter muscles and determine the distance of the tumor from your anus. In addition, a rectal ultrasound or pelvic MRI may be recommended to determine the depth of penetration of the tumor and any lymph node involvement. These tests together will help guide the next steps in treatment.

In general, cancers that have invaded through the muscle of the rectum (T3) or with lymph node involvement are treated with a combination of chemotherapy and radiation followed by surgery. These individuals are referred to a medical oncologist and radiation oncologist (who specializes in administering pelvic radiation) for neoadjuvant chemoradiation (chemotherapy and radiation given before surgery). Surgery is then performed 6-8 weeks after completion of chemoradiation. The time interval between radiation and surgery allows the tumor to continue to shrink and respond to the effects of the radiation.

Surgery involves removal of the rectum and the mesentery containing all the draining lymph nodes and reconnection of the colon to your low rectum or anus (Low anterior resection). The performance of a total mesorectal excision (TME) where the entire envelope of lymph node bearing tissue is removed together with the rectum is an important part of this procedure and significantly affects prognosis after surgery. A temporary ileostomy to divert the fecal stream may be necessary to allow the connection point to heal. Further chemotherapy may be necessary after surgery. Once you have completed chemotherapy or after 2 months if no further chemotherapy is planned, the ileostomy may be reversed. In patients with early stage rectal cancer (T1 or T2 and no evidence of lymph node spread on ultrasound or MRI) surgery (low anterior resection) is generally the primary treatment. Final decision on chemotherapy or radiation is once again made after the pathologist has staged the tumor. For cancers of the low rectum, sphincter sparing surgery may be an option if there is no involvement of the anal sphincter muscles. In certain cases, such as when the anal sphincter muscles are involved by the tumor, removal of the entire anus and rectum with a permanent colostomy may be necessary to give you the best chance at cure.

Regardless of your condition, Dr. Zaghiyan will walk you through the preoperative process, surgery, and postoperative recovery with care and compassion. Make an appointment for a private consultation with Dr. Zaghiyan in her office in Los Angeles for a thorough evaluation and treatment recommendations for your specific condition.