Radiotherapy and combined chemo-radiotherapy of rectal cancer.
During the last twenty years radiotherapy has been more frequently integrated with conventional demolitive surgery of rectal cancers because radical surgery, the treatment of choice of these tumors, has achieved a plateau of therapeutic results in the various stages of disease. The incidence of pelvic failures in stages B2 and C remains high, despite apparently complete resections. Disease-free interval, quality of life and survival are negatively affected. Radiotherapy at doses of about 50 Gy is able to destroy subclinical foci of disease after surgery (post-operative radiotherapy) or to reduce volume and infiltration of a locally extended tumor facilitating surgery (pre-operative radiotherapy). Moreover, radiotherapy proved to be effective in the treatment of pelvic recurrences. The great improvement of radiotherapeutic techniques in the last decade allows treatments at high doses to the target, minimizing the risk of side effects to contiguous normal tissues. A large number of clinical studies seems to demonstrate that the efficacy of radiotherapy is enhanced by combining chemotherapy both in the pre-operative approach and in the post-operative adjuvant treatment. To date, no definitive agreement about the optimal schedules of combined chemo-radiotherapy has been achieved. Many controlled studies are in progress investigating the most effective schedules with the minimal toxicity. The main indications of radiotherapy in the treatment of rectal cancer are here synthetically presented. Pros and cons of each approach are illustrated according to updated reports. For wider information on this topic of great interest and in progress the consultation of some reviews is suggested (1, 3, 23).
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Istituto Nazionale per lo Studio e la Cura dei Tumori, Milano.
D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D006801:Humans; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant; D013997:Time Factors; D016896:Treatment Outcome