Rectal cancer treatment

There is currently no definitive role for adjuvant radiation in colon cancer. However, patients who receive surgery for rectal cancer receive radiation therapy to reduce local tumor recurrence. Adjuvant radiation plus chemotherapy is considered standard treatment for patients with stage II or III rectal cancer after the surgical procedure is complete.17 Preoperative radiation may be used to reduce the initial size of rectal cancers in order to make the surgical procedure easier. 

Although often treated similarly to colon cancer, there are some important differences in the treatment of rectal cancer compared with colon cancer, especially in the adjuvant setting and the role of radiation. Rectal cancer involves tumors found in distal 15 cm of the large bowel and, as such, is very distinct from colon cancer in that it may recur both locally and dis-tally. The higher incidence of local failure and poorer overall... 

The Mayo Clinic/North Central Cancer Treatment Group (NCCTG) randomized patients with resected rectal cancer and tumor penetration through the rectal wall or with metastatically involved lymph nodes were assigned to postoperative radiation alone (45—... 

Based on the successful experience in colon carcinoma, the most recent Intergroup trial (INT-0114) explored the role of biomodulation of 5-FU in rectal cancer. This four-arm trial randomized patients to pelvic irradiation and 6 mo of bolus 5-FU vs bolus 5-FU and levamisole, leucovorin, or both (30). There was no significant difference in disease-free survival and overall survival (78-80%) among the four treatment arms in a prelimi-... 

Arenas RB, Fichera A, Mhoon D, Michelassi F. Total mesenteric excision in the surgical treatment of rectal cancer a prospective study. Arch Surg 1998 133(6) 608-612. 

Minsky BD. Primary treatment of rectal cancer present and future. Crit Rev Oncol Hematol 1999 32 19-30. 

In combination with a standard chemotherapeutic regimen (5-fluouracil-based), bevacizumab is used for the treatment of patients with malignant colon or rectal cancer, where it is indicated for the first- or second-line treatment. Bevacizumab in combination with bolus IFL is administered at a dose of 5mg/kg and lOmg/kg in combination with FOLFOX4. Bevacizumab is administered as an intravenous infusion. Its average half-life is approximately 20 days (ranging from 11 to 50 days) and the steady state is reached in 100 days. 

Lavery 1C, Lopez-Kostner F, Pelley RJ, Fine RM. Treatment of colon and rectal cancer. Surg Clin North Am 2000 80(2) 535-69. 

Adjuvant XRT plus chemotherapy is considered standard treatment for patients with stage E/in rectal cancer. Tumors arising in the rectum are technically more difficult to resect with wide... 

Douglass HO, Moertel CG, Mayer RJ, et al. Survival after postoperative combination treatment of rectal cancer. N Engl J Med 1986 315 1294-1295. 

The results are suggestive of the beneficial role of PDT in colorectal tumors. The application is most suitable for the treatment of smaller tumors or for sterilization of areas containing microscopic residual tumor in resection margins. For bulkier tumors, the use of PDT would need to be in conjunction with surgery or thermal laser irradiation. There is evidence that PDT is suitable for palliative treatment of advanced rectal cancers although there is only a limited experience with this and additional work is required. 

Along this same vein, Matsuhashi et al. described a rapidly growing invasive rectal cancer in 1 of 15 patients treated with sulindac for sporadic adenomatous colorectal polyps 16 months after sulindac treatment. They found that the adenomatous polyp had responded only partially to sulindac, and the rectal cancer developed following sulindac therapy and it showed immunostaining for COX-2. They concluded that while short-term sulindac therapy appears to cause some adenomatous colon polyps to regress, nevertheless it may not reliably prevent CRC in certain patients. 

Ariel IM, Padula G (1982) Treatment of asymptomatic metastatic cancer to the liver from primary colon and rectal cancer by the intraarterial administration of chemotherapy and radioactive isotopes. J Surg Oncol 20 151-156... 

For treatment of rectal cancer, minimally invasive surgery, such as transanal excision, transanal endoscopic microsurgery, total mesorectal excision, or abdominoperineal resection, are available depending on the location, size, and stage of the tumor (Pricolo... 

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