Adjuvant radiation therapy for colorectal cancer

Abstract

Background. Despite apparently complete resection of cancers of the rectum or colon, many patients have recurrences in the area from which their primary cancer was excised and in more distant organs. Radiation therapy has been used either alone or in combination with chemotherapy as an adjuvant to surgery to reduce the risk of recurrence. Methods. The literature describing the results of adjuvant radiation treatment for colorectal cancer was reviewed. Results. In randomized studies in patients with moderately advanced rectal cancers (T2‐4 NO, MO or N1‐3, MO) adjuvant radiation therapy has often reduced the risk of pelvic recurrence, but has had little effect on survival rates or the risk of extrapelvic metastases. Recent reports show that combined radiation and chemotherapy can improve both disease‐free survival and survival rates. Such treatment has caused only moderate toxicity in most studies. Nonrandomized studies in patients in whom small superficial rectal cancers are treated by local excision suggest that adjuvant radiation therapy reduces the risk of pelvic recurrence after this limited surgery and allows anorectal function to be preserved. Strategies similar to those developed for the treatment of rectal cancer are being studied in patients with colon cancer. Conclusions. In moderately advanced rectal cancers, the combination of chemotherapy and radiation is more effective than radiation alone in reducing local recurrence and increasing survival rates. Additional trials are needed to improve results and to refine drug and radiation schedules. Radiation alone may be sufficient as an adjuvant treatment when combined with local excision of small rectal cancers. The role of radiation in the adjuvant treatment of colon cancer is investigational. There is a need to more accurately delineate the patients with colorectal cancer most likely to benefit from adjuvant therapy.

Prevention of intra‐abdominal adhesions by using Seprafilm® in rats undergoing bowel resection and radiation therapy

“…It is well known that local failure is an important consideration for colorectal carcinomas [8,9,21]. The role of adjuvant preoperative or post‐operative irradiation in cancer of the rectum has been well established.…”

“…Surgery alone is an inadequate treatment for many patients with colon cancer as well as rectal cancer [8–10]. Although radiation therapy (RT) is frequently used as an adjuvant therapy to surgery for rectal cancer, there is no consensus about the use of RT after curative resection of colon cancer.…”

Administration of Lactobacillus plantarum 299v reduces side‐effects of external radiation on colon anastomotic healing in an experimental model

“…Tumour recurrence and regrowth of residual cancer cells following surgical excision of rectal carcinoma is almost inevitably fatal [3]. To reduce local and regional recurrences, neoadjuvant radiotherapy, with or without chemotherapy, is now advocated for the treatment of many patients with rectal carcinoma [24]. By giving primary adjuvant radiotherapy the incidence of local recurrences can be reduced by up to 50%.…”

Bisherige entwicklungen und aktueller stand der adjuvanten chemo- und radiotherapie beim kolon- und rektumkarzinom

“…Ge-genw~trtig liegen keine Daten vor, welche eine routinemfigige adjuvante Bestrahlung dieses Kollektivs rechtfertigen warden [12][13][14]. Allenfalls erscheint eine auf retroperitoneal fixierten Abschnitte gerichtete Radiatio potentiell sinnvoll.…”

“…25-50% aller am Rektumkarzinom versterbenden Patienten zeigen lediglich isolierten pelvinen Tumorbefall [12,13]. Lokalrezidive treten hfiufiger als beim Kolonkarzinom auf.…”