Rectal Cancer

Research

Mayo Clinic is an international leader in rectal cancer research. Mayo Clinic physicians have led the study and use of minimally invasive (laparoscopic) surgery for colon and rectal cancers, performing more than 1,000 such surgeries since 1991. Mayo Clinic physicians also have one of the world's largest experiences in the use of intraoperative radiation (IORT) as treatment for patients with locally advanced primary or locally recurrent colon and rectal cancer. In addition, Mayo physicians contributed significantly to advances in chemotherapy, expanded roles for surgery, pharmacogenetic testing and stool testing. Mayo Clinic was involved in clinical trials that resulted in the approval of the drug oxaliplatin for the treatment of advanced colon and rectal cancer. Mayo Clinic doctors are at the forefront of evaluating the effectiveness of computerized tomographic (CT) colonography, the so-called virtual colonoscopy, which offers patients a quicker, more comfortable exam. Ongoing research projects being conducted by Mayo Clinic physicians and researchers include the following topics: techniques for removing large polyps in the rectum; the risk of lymph node metastasis in early carcinoma of the rectum; staging rectal carcinoma; and oophorectomy in colon and rectal cancer.

Mayo physicians are constantly researching new ways to treat cancer. Treatment recommendations could include some new developments:

New Chemotherapy Drugs

Chemotherapy remains the main treatment for rectal cancer that has spread to other parts of the body. Researchers continue to seek new drugs to improve outcomes. Physicians at Mayo Clinic provide access to some promising medications through clinical trials.

Laparoscopic Surgery

A surgeon makes several tiny incisions and inserts small instruments with attached cameras. These instruments display the rectum on a video monitor and allow the surgeon to remove small cancers. Researchers at Mayo Clinic are studying whether laparoscopic surgery reduces discomfort and recovery time.

An Expanded Role for Surgery

Recent studies show that an increasing number of people who have rectal cancer may be candidates for surgery. For example, people who have cancer that has spread to the liver or to the lungs may still be candidates for surgery. Surgery may be combined with other treatments such as chemotherapy. Researchers at Mayo Clinic are performing clinical trials that examine a new role for surgery.

Pharmacogenetic Testing

Mayo Clinic geneticists conduct research to predict who will gain the most benefits from certain chemotherapy agents for the treatment of widespread cancer. Geneticists also conduct research to predict who will have the most notable side effects. The answers to these questions are important for cancer patients and health-care providers as they make decisions about treatment of rectal cancer. Mayo Clinic geneticists, oncologists and other researchers want to determine whether DNA gives clues about drugs that can reduce side effects and improve results for people with cancer.

Stool Testing

Researchers at Mayo Clinic are studying a technique that may be more sensitive for detecting colon and rectal tumors than fecal occult blood testing. Based on the idea that tumors shed cells into the stool, the new test uses highly sensitive DNA techniques. Researchers hope that the new technique will promote earlier detection and treatment of rectal cancer.

Intraoperative Radiation

Many times, cancer in the rectum can be surgically removed if the areas around the tumor (margins) are cancer-free. When a cancer occurs close to other vital organs, however, a few cancer cells may be left behind. In such cases, physicians at Mayo Clinic may use intraoperative radiation, high doses of electron radiation given in the operating room. This radiation is intended to kill off remaining cancer cells while normal structures are surgically displaced. Patients with locally advanced primary or locally recurrent rectal cancers will also receive a course of external beam radiation combined with chemotherapy before or after maximal surgical removal of the cancer and IORT.

Publications

Research by Mayo Clinic doctors has been published widely. Some recent publications include:

Kozelsky TF, Meyers GE, Sloan JA, Shanahan TG, Dick SJ, Moore RL, Engeler GP, Frank AR, McKone TK, Urias RE, Pilepich MV, Novotony PJ, Martenson JA. Phase III double-blind study of glutamine versus placebo for the prevention of acute diarrhea in patients receiving pelvic radiation therapy. J Clin Oncol 2003 May 1; 21(9):1669-74. [Abstract]

Lavertu S, Schild SE, Gunderson LL, Haddock MG, Martenson JA. Endocavitary radiation therapy for rectal adenocarcinoma - 10-year results. American Journal of Clinical Oncology-Cancer Clinical Trials 2003 Oct; 26(5):508-12. [Abstract]

Gunderson LL, Sargent DJ, Tepper JE, O'Connell MJ, Allmer C, Smalley SR, Martenson JA, Haller DG, Mayer RJ, Rich TA, Ajani JA, MacDonald JS, Goldberg RM. Impact of T and N substage on survival and disease relapse in adjuvant rectal cancer: A pooled analysis. Int J Radiat Oncol Biol Phys 2002 Oct 1; 54(2):386-96. [Abstract]

Miller RC, Sargent DJ, Martenson JA, MacDonald JS, Haller D, Mayer RJ, Gunderson LL, Rich TA, Cha SS, O'Connell MJ. Acute diarrhea during adjuvant therapy for rectal cancer: A detailed analysis from a randomized intergroup trial. Int J Radiat Oncol Biol Phys 2002 Oct 1; 54(2):409-13. [Abstract]

Tepper JE, O'Connell M, Niedzwiecki D, Hollis DR, Benson AB, Cummings B, Gunderson LL, Macdonald JS, Martenson JA, Mayer RJ. Adjuvant therapy in rectal cancer: Analysis of stage, sex, and local control - Final report of intergroup 0114. J Clin Oncol 2002 Apr 1; 20(7):1744-50. [Abstract]