title: Postoperative radiochemotherapy in rectal cancer comparison of two combination schemes: alternating versus concomitant.
abstract: OBJECTIVE
  To compare the results on disease control and toxicity of two different schedules of adjuvant combined treatment in advanced rectal cancer.
  
  
  METHODS
  From January 1995 to September 1998, 127 patients with stage B2-C rectal cancer were treated with postoperative chemotherapy and radiotherapy with two different schemes: three cycles of 5-fluorouracil and leucovorin followed by pelvic radiotherapy and three weeks after radiation therapy was completed, another three cycles of chemotherapy were administered (alternating arm), or two cycles of 5-fluorouracil and leucovorin followed by concurrent radiochemotherapy and three weeks after ending another two cycles of 5-fluorouracil and leucovorin were administered (concomitant arm).
  
  
  RESULTS
  Grade 3 acute toxicity was more frequent in the concomitant schedule group (33% vs 13%, P = 0.014). In the alternating schedule group, the acute adverse effects were observed after an average radiation dose of 28.4 Gy and in the concomitant schedule group after an average dose of 22.7 Gy (P = 0.012). In the arm of concomitant treatment, 37.8% of patients had to interrupt the irradiation for severe toxicity compared to 10.4% in the arm of alternating treatment (P = 0.001). There was no difference in the rate of late toxicity. The actuarial overall survival rates at 3 and 5 years were, respectively, 68.8% and 56.6% in the alternating arm and 75.5% and 61.8% in the concomitant arm (P = 0.4599). There were no differences between the two arms in the 5-year actuarial rates of overall recurrence (47% vs 51.3%, P = 0.722), local recurrence (34.6% vs 35.7%, P = 0.935) or distant recurrence (32.7% vs 31.8%, P = 0.983).
  
  
  CONCLUSIONS
  For patients with B2-C rectal cancer, postoperative treatment with an alternating scheme of chemoradiotherapy is as effective as a concomitant scheme in control of the disease. The concomitant scheme had a higher incidence, earlier appearance and higher severity of intestinal acute toxicity than the alternating scheme, with a lower completion rate of chemoradiotherapy but without any influence on late toxicity incidence.
authors.affiliation: Department of Radiation Oncology, Hospital Clinic Universitario Lozano Blesa, Zaragoza, Spain. jvalenciaj@hotmail.com
authors.forename: Javier
authors.initials: J
authors.lastname: Valencia
authors.forename: Ricardo
authors.initials: R
authors.lastname: Escó
authors.forename: Sofía
authors.initials: S
authors.lastname: Polo
authors.forename: Natividad
authors.initials: N
authors.lastname: Bascón
authors.forename: Pilar
authors.initials: P
authors.lastname: Escudero
authors.forename: Vicente
authors.initials: V
authors.lastname: Alonso
mesh_terms: D000328:Adult; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000008:administration & dosage; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000009:adverse effects*; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D006801:Humans; D002955:Leucovorin / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects*; D012004:Rectal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000964:Antimetabolites, Antineoplastic; D002955:Leucovorin; D005472:Fluorouracil