The Other Women’s Cancer

Although many women believe colorectal cancer to be a disease that affects men only, each year it takes the lives of just as many women as men. In fact, colorectal cancer takes the lives of more women each year than does ovarian, uterine, or cervical cancer.1 The good news is, with utilization of recommended screening options (see Table 1),2 colorectal cancer can be prevented altogether; and for those who are diagnosed with this disease, there are more treatment options available than ever before.

Who Is at Risk of Colorectal Cancer?Both men and women are at risk of developing colorectal cancer. In most cases colorectal cancer occurs in people age 50 or older, but younger individuals can also get this disease. In addition, there is some evidence to suggest that people of African-American or Ashkenazi Jewish descent are at increased risk of developing colorectal cancer.

Medical risk factors for colorectal cancer include:

Personal or family history of colorectal polyps or cancerPersonal history of inflammatory bowel diseasePersonal or family history of an inherited genetic cancer syndrome, such as familial adenomatous polyposis (FAP) or hereditary nonpolyposis colon cancer (HNPCC)Women who do not have any of these risk factors are considered at average risk for colorectal cancer and should begin screening at age 50. Women who do have one or more of these risk factors are considered at increased risk of the disease. Although these medical factors cannot be changed, women at increased risk can protect themselves by discussing their risk factors with their physician and undergoing earlier and more frequent screening as appropriate.

Lifestyle risk factors for colorectal cancer include obesity, physical inactivity, smoking, heavy alcohol consumption, a diet high in red or processed meats, and a diet inadequate in fruits and vegetables. Fortunately, these are risk factors that can be changed. Women who have any of these lifestyle risk factors can consult their physician or nutritionist about adjusting their lifestyle to reduce their colorectal cancer risk and optimize their overall health and well-being.3
The second step to reducing the risk of developing colorectal cancer and detecting any cancer early is to be vigilant about undergoing the recommended screening for this disease.

Who Should Be Screened and When?Colorectal cancer screening allows for both the prevention and the early detection of cancer. Early detection in turn allows for early treatment, when a cure is most likely. Indeed the five-year survival rate is 90 percent when this disease is detected in its early, localized stage.1 In addition, colorectal cancer is preventable when potentially precancerous colorectal polyps are detected and removed before they have the chance to develop into cancer.

It is hoped that with an increased awareness of the lifesaving benefit of colorectal cancer screening, more women will undergo this testing and colorectal cancer incidence and mortality rates will continue to decline.

For women and men at average risk for colorectal cancer, the American Cancer Society recommends one of the seven screening options, beginning at age 50 (see Table 1).2 In people who are at increased risk for colorectal cancer, screening may need to begin at a younger age and be performed at more-frequent intervals.

What Are the Symptoms?Early colorectal cancer causes no symptoms, which is why screening ideally begins when an individual feels well—before any symptoms of disease develop. As the cancer grows, however, symptoms may develop; these include rectal bleeding or blood in the stool, a change in bowel habits, abdominal pain, and unexplained fatigue.

In some cases people who experience the symptoms of colorectal cancer ignore them because they are scared or embarrassed. It’s important to understand that, first, these symptoms do not necessarily indicate colorectal cancer; they could be caused by another, less serious condition. Second, if the symptoms are due to colorectal cancer, this disease is treatable. And, third, no one should die of embarrassment. Anyone who experiences the symptoms of colorectal cancer should see a physician for prompt evaluation and diagnosis—the earlier the diagnosis, the greater the chance for cure.

What Are the Treatment Options?If a diagnosis of colorectal cancer is made, staging of the disease is the next step in the treatment plan. The term staging refers to the local and distant extent of the disease and provides a framework for outlining treatment options and discussions regarding prognosis. An important step in this process is a review of the biopsy specimen by a pathologist. This should be done prior to making any decisions regarding the need for further studies or surgery. This is especially important for cancerous polyps, which may sometimes be fully removed with surgery. Other parts of the staging process include a physical examination by the physician; imaging studies, such as a CT scan, PET scan, or endoscopic ultrasound; and laboratory blood tests, including tumor markers.

The staging of colorectal cancer is based on the depth of invasion of the cancerous tumor through the colon or rectal wall, and an integral component is the determination of whether cancer cells have spread to nearby lymph nodes or to distant organs. Stages I and II colorectal cancers are considered localized early-stage tumors that do not have lymph node involvement. Stage III colorectal cancer is locally advanced and has involvement of regional lymph nodes. Stage IV colorectal cancer indicates disease that has metastasized, or spread outside the colon to distant organs.4 Staging is critical in determining prognosis in colorectal cancer, as earlier-stage disease indicates longer survival and a better chance for cure.

Surgery

Surgery is the only curative treatment for localized colorectal cancer. Surgery is often required for diagnosis and staging of the disease or for bleeding or obstruction associated with the tumor. Surgery entails removal of the cancerous tumor, as well as an adequate amount of normal tissue surrounding the tumor, and removal of regional lymph nodes.

ChemotherapyWhen a disease recurrence develops after a potentially curative surgical

procedure, it is believed to come from microscopic tumor cells that are present and undetectable at the time of surgery. The goal of adjuvant (postoperative) chemotherapy is to eradicate these microscopic tumor cells to decrease the likelihood of recurrence and to increase the cure rate. Data from multiple clinical trials over the past 50 years support the routine use of adjuvant systemic chemotherapy after surgical resection of colon cancer with lymph node involvement. Adjuvant chemotherapy is associated with an approximately 30 percent reduction in the risk of disease recurrence and a 22 to 32 percent reduction in mortality.5 The average length of adjuvant chemotherapy treatment is six months. The routine use of adjuvant chemotherapy for Stage II colon cancer is controversial and is considered only for patients with tumors with features that may increase the rate of recurrence.

Radiation Therapy

Radiation therapy has emerged as a significant part of adjuvant treatment for rectal cancer, whereas adjuvant treatment of colon cancer that is removed by surgery includes chemotherapy alone. This is due to a higher rate of local recurrence in the pelvis in patients with rectal cancer. A series of clinical trials in the 1980s and 1990s determined that there is a survival advantage when postoperative radiation therapy is combined with chemotherapy following resection of Stage II and III rectal cancers.5,6,7,8,9,10
Chemotherapy and Targeted Therapies
Systemic chemotherapy and targeted antibody therapies represent newer treatment options for Stage IV colorectal cancer (disease that has spread to other sites in the body, also called metastatic disease). Approximately 30 to 40 percent of patients with colon or rectal cancer have metastatic disease at the time of diagnosis. Combining chemotherapy with targeted antibody therapy has been shown to improve survival in people with metastatic disease.11,12,13 The past decade in cancer therapy has led to the development of novel targeted therapies that enable people to live longer with metastatic disease. There is increased understanding of the biologic processes important for survival and growth of colorectal cancer cells, including the role of angiogenesis, which is the process by which a tumor makes blood vessels to support its own growth.13

Another important growth pathway in metastatic colorectal cancer is the epidermal growth factor receptor (EGFR) pathway. EGFR transmits signals through a set of proteins inside the cancer cell that instruct the cancer cell to reproduce and metastasize. Data suggest that blocking EGFR stops this growth signal. Antibodies have been developed that block the EGFR pathway (EGFR-blockers). These antibodies are used in combination with chemotherapy to slow the growth of tumors. In 2008 significant information about the use of EGFR-blockers was presented and published. This relates to another important gene inside the cancer cell called K-ras, which also controls cancer cell growth. Some tumors have mutations in the K-ras gene; this mutation leaves the K-ras protein always turned “on,” so signaling within the cancer cell continues regardless of whether the EGFR is blocked with an antibody. Mutations in the K-rasgene occur in approximately 40 percent of metastatic colorectal cancer patients. This finding is important because it affects what therapies can be used to fight the cancer.14,15