Treatment

Colorectal Cancer Nomogram This prediction tool calculates the probability of being disease-free from colon cancer five to ten years after surgery more

Surgery is a common treatment for many stages of colorectal cancer. In cases where the cancer is found fairly early, surgical removal of the tumor can lead to a cure. Many colorectal cancer patients naturally are concerned about preserving normal bowel, urinary, and sexual function after treatment, and at Memorial Sloan-Kettering, we are continually developing and refining new techniques to evaluate such function in people who have had major restorative colorectal surgery.

• Surgery for Colon Cancer

  Occasionally, the cancer may be limited to a portion of a polyp. Many such patients are cured by polyp removal alone, usually during a colonoscopy.

  In other patients with cancer of the colon, surgery is more extensive and involves removal of the segment of the colon that contains the tumor as well as nearby lymph nodes to which the cancer might have spread. This procedure, called a hemi-colectomy, may require removal of several inches of the bowel. In most such cases, the bowel is reconstructed by sewing or stapling together the two ends of the remaining bowel. Fortunately, the body tolerates such surgery quite well, and bowel function usually returns to normal in just a few months. There is usually no need for a permanent colostomy bag to collect wastes, though sometimes surgeons create a temporary colostomy to allow the colon to heal before it is allowed to resume its normal functions.

• Minimally Invasive (Laparoscopic) Surgery for Colorectal Cancer

  Advances in technology and fiber optics allow surgeons to perform complex procedures through small incisions. Miniature video cameras and long thin instruments are utilized. Memorial Sloan-Kettering currently performs a significant portion of colorectal surgeries laparoscopically. Most patients who desire and are candidates for minimally invasive surgery can undergo a laparoscopic procedure.

  Laparoscopy offers advantages over conventional open abdominal surgery because of the smaller incisions employed: an open (conventional) surgery incision could be 20 to 25 centimeters (8 to 10 inches), while a laparoscopic incision is usually only 3 to 4 centimeters (1.5 to 2 inches). As a result, patients undergo less trauma, recover quicker, and can return to their usual activities sooner following a minimally invasive procedure.

  Several studies have shown that patient outcome (in terms of overall survival and risk of recurrence) was similar between those who had laparoscopic colon cancer surgery and those whose surgery was performed through a conventional open approach. Other studies assessing patient outcome following laparoscopic surgery for colorectal cancer are ongoing.

• Surgery for Rectal Cancer

  Surgery for rectal cancer is often more complex. Small cancers in the rectum that have not grown through the wall of the bowel are often treated with local removal of the growth (similar to a lumpectomy for breast cancer, in that as little as possible of the surrounding healthy tissue is removed), with or without radiation therapy. Surgeons are currently evaluating the use of laparoscopy to remove rectal cancers and are helping to lead national clinical trials to assess this approach.

  Local excision -- removal of superficial cancers and a small amount of nearby tissue from the wall of the rectum -- can be performed through the anus using special equipment and fiberoptic lighting. Tumors that require more extensive local excision can be performed through a small incision in the back, just above the anus.

  Some cancers that have grown through the wall of the rectum or involve the lymph nodes may require more extensive surgery. Memorial Sloan-Kettering surgeons have pioneered a technique called "sharp mesorectal excision" for such patients. This approach allows the delicate removal of all cancerous tissue in and around the rectum, but carefully avoids severing the nerves that are involved in sexual and urinary function, and also enables most patients to avoid a permanent colostomy. Such nerve-preserving surgery is the standard of care at Memorial Sloan-Kettering.

  In some patients, such as men with large prostate glands, such techniques may not be feasible, and "coloanal reconstruction" is needed. This approach allows the surgeon to remove the rectum, but eliminates the need for a permanent colostomy because the surgeon can sew the upper colon directly to the anus with the use of specialized equipment. Memorial Sloan-Kettering surgeons found that in some such cases, the upper colon was too small to provide an adequate rectal reservoir, so they developed a way to construct an internal colon pouch (the J-Pouch). During this procedure, surgeons loop two sections of the lower colon upon itself and open up the wall between them to create a larger reservoir for storing wastes, essentially replacing the rectum.

• Transanal Endoscopic Microsurgery

  Memorial Sloan-Kettering is the most experienced institution in the Tri-State area offering transanal endoscopic microsurgery (TEM) -- surgery performed via a scope inserted into the anus which allows for removal of early-stage rectal cancers less invasively. This approach is especially suitable for patients who are too ill or elderly or prefer not to undergo a standard abdominal operation.

  The 4-centimeter scope contains a camera that magnifies the surgical field sixfold to enhance the surgeon's view. Following inflation of the rectum with carbon dioxide (a standard approach used to facilitate minimally invasive surgery), the surgeon can insert long surgical instruments via the scope to perform a precise procedure 10 inches up into the rectum. Following removal of the tumor, the surgeon can then stitch the area closed through the same scope.

  The entire procedure typically takes just two hours; patients can usually go home the next day and recover fully within a week. Because nerves controlling bladder and sexual function are spared during this procedure, patients usually retain sexual and urinary function.

• Surgery to Remove Metastases

  Surgery may also be performed to remove metastases -- cancerous tissue in other organs to which the colorectal cancer has spread. Liver metastases -- the spread of cancer cells to the liver -- are common in patients with advanced colorectal cancer. About 15 percent of patients have liver metastases when they are first diagnosed with advanced cancer, and 50 to 75 percent of patients with advanced disease go on to develop liver metastases. Some of these patients are treated by surgically removing part of the liver. Others undergo cryosurgery, in which the tumors are frozen but not removed. Surgery may also be done to remove metastases in the lungs.

Specially trained doctors called interventional radiologists perform image-guided, minimally invasive procedures to treat metastases from colon cancer, including those in the liver and lung.

Up to half of patients with colorectal cancer develop liver metastases during the course of their disease. Although surgery is the treatment of choice, most patients are not able to undergo surgery -- making alternative treatments, such as radiofrequency (RF) ablation, an alternative option. This technique kills tumor cells via a special needle that delivers localized heat. This therapy can kill the tumor without removing it and without affecting parts of the body outside of the liver.

The effectiveness of RF ablation for liver metastases has been confirmed in several recent studies. For selected patients with relatively few small colon cancer metastases in the liver, overall survival rates after ablation of metastases are comparable to those achieved after surgery.

The ablation approach can also be used to destroy lung metastases without having to remove them surgically. This new treatment is increasingly being used in patients with colon cancer metastases to the lung who cannot undergo surgery. Early results of a few clinical trials show that for selected patients with a few small tumors, ablation can be an effective and safe treatment to control disease locally.

Many patients will be free of all cancer following surgery. However, in some patients, microscopic tumor cells that were not detectable before or during surgery will eventually grow. As a result, many patients, such as those whose cancer has spread to the lymph nodes, now receive chemotherapy (for colon cancer) or chemotherapy and radiation therapy (for rectal cancer) in addition to surgery. Such adjuvant therapy given in addition to surgery increases the chance of a complete cure by destroying microscopic accumulations of cancer cells before they have an opportunity to grow larger.

• Therapy Prior to Surgery

  Specialists at Memorial Sloan-Kettering evaluate patients with rectal cancer to determine if they would benefit from receiving chemoradiation therapy prior to surgery, known as preoperative combined modality therapy. This is the standard recommendation for patients with locally advanced rectal cancer and some patients who have low-lying tumors in whom we hope to achieve sphincter-sparing surgery. By giving the therapy before surgery, doctors can shrink the tumor, allowing for reconstruction of the bowel and usually avoiding the need for a permanent colostomy. This technique has resulted in an overall cure rate of more than 70 percent for patients with rectal cancer and a local recurrence rate of less than 10 percent.

• Therapy After Surgery

  At Memorial Sloan-Kettering, we commonly deliver adjuvant therapy after surgery. In advanced metastatic cancer, radiation therapy may also be used to relieve symptoms such as intestinal blockage, bleeding, or pain.

  Our investigators also led studies leading to the approval of the drugs oxaliplatin and cetuximab. Oxaliplatin is now commonly used, along with 5-fluorouracil and leucovorin (a regimen called FOLFOX), to treat stage III colorectal cancer that has been surgically removed, as well as for stage IV (metastatic) colorectal cancer. The drug has been shown to slow cancer growth, reduce the risk of recurrence, and (in some patients) improve survival. Cetuximab is a drug used alone or in combination with irinotecan to slow disease progression in patients with metastatic colorectal cancer.

  Chemotherapy drugs used to treat colorectal cancer include 5-fluorouracil, leucovorin, irinotecan, and capecitabine, and more recently, cetuximab, bevacizumab, oxaliplatin, and panitumumab. Memorial Sloan-Kettering researchers helped establish the effectiveness of irinotecan, a drug now approved for the initial treatment of metastatic colorectal cancer when given with 5-fluorouracil and leucovorin, and for patients with metastatic colorectal cancer that has persisted or returned despite prior chemotherapy.

  Our investigators also led studies leading to the approval of the drugs oxaliplatin and cetuximab. Oxaliplatin is now commonly used, along with 5-fluorouracil and leucovorin (a regimen called FOLFOX), to treat stage III colorectal cancer that has been surgically removed, as well as for stage IV (metastatic) colorectal cancer. The drug has been shown to slow cancer growth, reduce the risk of recurrence, and (in some patients) improve survival. Cetuximab is a drug used alone or in combination with irinotecan to slow disease progression in patients with metastatic colorectal cancer. Bevacizumab and panitumumab are two other targeted therapies used to slow disease progression in patients with metastatic colorectal cancer.

Our doctors are involved in ongoing efforts to decrease the damage to healthy tissues that may occur during radiation therapy for rectal and anal cancers. Targeted approaches focus on tumor tissue while reducing the chance of uncomfortable side effects such as diarrhea and gas. These techniques can also reduce radiation exposure to the pelvic bones, potentially decreasing the risk of osteoporosis.

For example, selected patients whose rectal cancer has recurred in the pelvis after surgery and radiation therapy may undergo intraoperative radiation therapy (IORT). The surgeon removes the tumor, and while still in the operating room, the patient receives a high dose of iridium radiation to the area where the surgeon believes cancer cells could still be lurking. Because the radiation therapy is done during the surgical procedure and can be delivered to a precisely defined area, it is possible to use a higher-than-usual -- and therefore more effective -- dose of radiation and to spare nearby healthy tissues.

Intensity-modulated radiation therapy (IMRT) is a type of 3-D radiation therapy that targets tumors with greater precision than conventional radiation therapy. Using highly sophisticated computer software and 3-D images from CT scans, the radiation oncologist can develop an individualized treatment plan that delivers high doses of radiation to cancerous tissue while sparing surrounding organs and reducing the risk of injury to healthy tissues. At Memorial Sloan-Kettering, we use IMRT in patients with anal cancer, patients with low-lying rectal cancers, and those with rectal cancer that has recurred after surgery. Patients with anal and rectal cancers may also receive chemotherapy drugs that sensitize the tumor to the effects of radiation.

Patients with recurrent rectal cancer who have had prior radiation therapy to the pelvis may be treated with image-guided radiation therapy, which can be done in as few as three treatments. This novel, highly targeted form of treatment can be used to locate the tumor target before the radiation dose is given while the patient is in the treatment position, using implanted clips or bone landmarks for guidance.

Memorial Sloan-Kettering is assessing new drug combinations for patients with colorectal cancer, ways to enhance quality of life after rectal cancer treatment, and the use of imaging procedures such as PET scanning to improve treatment planning.

Research protocols are available for eligible patients through the clinical trial process. For up-to-date details about current clinical trials at Memorial Sloan-Kettering, please visit our clinical trials database.

• Intrahepatic Pump for Advanced Colorectal Cancer

  Patients whose disease has spread to the liver benefit from a comprehensive program that includes physicians from colorectal surgery, liver surgery, and medical oncology, who work together to maximize long-term survival. Those whose disease cannot be treated with surgery may receive chemotherapy through an innovative liver pump that delivers drugs directly to the liver, rather than to the entire body. Memorial Sloan-Kettering's colorectal and liver physicians have pioneered these novel treatment approaches.

In 2006, a multi-institutional study led by Memorial Sloan-Kettering investigators reported that patients whose colorectal cancer had spread to the liver and who received such "intrahepatic" chemotherapy lived longer than those receiving systemic (intravenously administered) chemotherapy, and had better response rates and a longer time to disease progression in the liver.¹

[1] Kemeny NE et al. Hepatic arterial infusion versus systemic therapy for hepatic metastases from colorectal cancer: a randomized trial of efficacy, quality of life, and molecular markers (CALGB 9481). J Clin Oncol. 2006;24(9):1395-1403.