Following surgical removal of colon cancer, the cancer is referred to as Stage II if the final pathology report shows that the cancer has penetrated the wall of the colon into the abdominal cavity, but does not invade any of the local lymph nodes and cannot be detected in other locations in the body.
Stage II adenocarcinoma of the colon is a common and frequently curable cancer. Depending on features of the cancer, 60-75% of patients are cured without evidence of cancer recurrence following treatment with surgery alone. Stage II cancer can be further divided into three stages: IIA, IIB, and IIC. In Stage IIA, the tumor has grown through the outermost layers of the colon into tissues surrounding the colon. In Stages IIB and IIC, the involvement of other tissues and organs is more extensive. Stage II colon cancer does not, however, involve the lymph nodes or distant parts of the body.
Despite undergoing complete surgical removal of the cancer, 25-40% of patients with Stage II colon carcinoma experience recurrence of their cancer. Typically, cancer recurs because there are small amounts of cancer that had spread outside the colon and were not removed by surgery. These cancer cells cannot be detected with any of the currently available tests. Undetectable areas of cancer outside the colon are referred to as micrometastases. The presence of micrometastases causes the relapses that follow surgical treatment. An effective treatment is needed to eliminate micrometastases and improve cure rates of Stage II cancer. Efforts are currently underway to find such a therapy.
The following is a general overview of treatment for Stage II colon cancer. Treatment may consist of surgery, radiation, chemotherapy and/or targeted therapy (drugs which act by a different mechanism than chemotherapy to target tumor cells). Multi-modality treatment, which is treatment using two or more techniques, is increasingly recognized as an important approach for increasing a patient’s chance of cure or prolonging survival. In some cases, participation in a clinical trial utilizing new, innovative therapies may provide the most promising treatment. Circumstances unique to each patient’s situation may influence how these general treatment principles are applied and whether the patient decides to receive treatment. The potential benefits of multi-modality care, participation in a clinical trial, or standard treatment must be carefully balanced with the potential risks. The information on this website is intended to help educate patients about their treatment options and to facilitate a mutual or shared decision-making process with their treating cancer physician.
Conventional surgery for colon cancer requires surgeons to create a large opening in the abdomen in order to reach the cancer. This procedure involves the removal of the cancer, along with some of the normal bowel and lymph nodes that were surrounding the cancer. After this removal, the two cut ends of the colon are sewn together. In some instances, a temporary colostomy is created and the two ends of the colon are reconnected at a later time. A colostomy is an opening where the large intestine is attached to the abdominal wall and allows passage of stool into a replaceable bag outside of the patient’s body. In some instances, when the cancer cannot be completely removed, the two ends are not re-sewn together and the patient has a permanent colostomy.
The delivery of cancer treatment following local treatment with surgery is referred to as “adjuvant” therapy and may include chemotherapy, radiation therapy, and/or targeted therapy. Adjuvant chemotherapy improves outcomes among patients with Stage III colon cancer, but the benefits among patients with Stage II colon cancer are less clear. A review of previously published clinical trials reported that adjuvant chemotherapy may improve disease-free survival, but does not appear to improve overall survival, among patients with Stage II colon cancer.1 Routine use of adjuvant chemotherapy is not recommended for patients with Stage II colon cancer, but it may be considered for some patients, particularly those whose cancers have high-risk features.2 Risk of cancer recurrence can be estimated based on the specific characteristics of the cancer, as well as by genomic tests such as Oncotype DX.3
A newer test that may help guide treatment decisions for patients with Stage II colon cancer is the Oncotype DX colon cancer test. This test—which is similar to a test that is commonly used for patients with early-stage breast cancer—is performed after surgery but before final decisions are made about adjuvant (post-surgery) therapy. The test estimates the risk of cancer recurrence by evaluating the activity of certain genes in a sample of tumor tissue. Risk of recurrence can vary greatly among patients with Stage II colon cancer, and use of the Oncotype DX test in combination with other markers of risk may help to individualize treatment decisions.
Treatment of the Elderly
A large percentage of patients with colon cancer are 65 years or older. Sometimes elderly patients and/or their physicians may believe that believe that treatment will be more toxic for elderly patients than it is for their younger counterparts. Due to this perceived intolerability of therapy, elderly patients often do not receive optimal treatment.4 Many older patients are able to tolerate standard treatment, however, and receipt of standard treatment improves cancer outcomes. Elderly patients with colon cancer eligible for adjuvant therapy should speak with their physician regarding their individual risks and benefits of adjuvant therapy.
Strategies to Improve Treatment
The development of more effective cancer treatments requires that new and innovative therapies be evaluated with cancer patients. Clinical trials are studies that evaluate the effectiveness of new drugs or treatment strategies. Future progress in the treatment of Stage II colon cancer will result from the continued evaluation of new treatments in clinical trials. Participation in a clinical trial may offer patients access to better treatments and advance the existing knowledge about treatment of this cancer. Patients who are interested in participating in a clinical trial should discuss the risks and benefits of clinical trials with their physician. Areas of active exploration to improve the treatment of Stage II colon cancer include the following:
New Adjuvant Chemotherapy Regimens: Several new chemotherapy drugs show promising activity for the treatment of advanced or recurrent rectal cancer. Development of new multi-drug chemotherapy treatment regimens that incorporate new or additional anti-cancer therapies for use as neoadjuvant and/or adjuvant treatment is an active area of clinical research.
Laparoscopic surgery: Laparoscopic surgery is used for many types of surgery with the short-term advantages of less pain, fewer wound complications, quicker post-operative recovery, and shorter hospital stays. Instead of making one long incision in the abdomen, the surgeon makes several smaller incisions. Special long instruments are inserted through these incisions to remove part of the rectum and lymph nodes. One of the instruments has a small video camera on the end, which allows the surgeon to see inside the abdomen. Once the diseased part of the rectum has been freed, one of the incisions is made larger to allow for its removal.
Laparoscopic-assisted surgery appears to be about as likely to be curative as the standard approach for earlier-stage cancers.5 However, there is still limited information from randomized trials about the approach. In addition, laparoscopic surgery requires special expertise and patients need to be treated by a skilled surgeon who has done a lot of these operations.
Targeted Therapies: Targeted therapies are anticancer drugs that interfere with specific pathways involved in cancer cell growth or survival. Some targeted therapies block growth signals from reaching cancer cells; others reduce the blood supply to cancer cells; and still others stimulate the immune system to recognize and attack the cancer cell. Depending on the specific “target”, targeted therapies may slow cancer cell growth or increase cancer cell death. Targeted therapies may be used in combination with other cancer treatments such as conventional chemotherapy. Targeted therapies that have shown a benefit for selected patients with advanced colon cancer include Avastin® (bevacizumab), Erbitux® (cetuximab), and Vectibix® (panitumumab).
Managing Side Effects: Techniques designed to prevent or control the side effects of cancer and its treatments are called supportive care. Side effects not only cause patients discomfort, but also may prevent the delivery of therapy at its planned dose and schedule. In order to achieve optimal outcomes from treatment and improve quality of life, it is imperative that treatment is delivered as planned and that side effects resulting from cancer and its treatment are appropriately managed. For more information, go to Managing Side Effects.
1 Figuerdo A, Coombes ME, Mukherjee S. Adjuvant therapy for completely resected stage II colon cancer. Cochrane Database of Systematic Reviews. 2008;(3):CD005390.
2 Benson AB, Schrag D, Somerfield MR. American Society of Clinical Oncology recommendations on adjuvant chemotherapy for stage II colon cancer. Journal of Clinical Oncology. 2004;15:3408-19.
3 Gray RG, Quirke P, Handley K et al. Validation study of a quantitative multigene reverse transcriptase-polymerase chain reaction assay for assessment of recurrence risk in patients with stage II colon cancer. Journal of Clinical Oncology. Early online publication November 7, 2011
4 Kahn KL, Adams JL, Weeks JC, et al. Adjuvant chemotherapy use and adverse events among older patients with stage III colon cancer. Journal of the American Medical Association .2010;303:1037-1045.
5 Jayne DG, Thorpe HC, Copeland J et al. Five-year follow-up of the Medical Research Council CLASICC trial of laparoscopically assisted versus open surgery for colorectal cancer. British Journal of Surgery. 2010;97:1638-45.