title: Pelvic exenteration for locally advanced rectal carcinoma: factors predicting improved survival.
abstract: BACKGROUND
  The purpose of this retrospective review was to determine whether a number of clinicopathologic factors (age, gender, type of exenteration, tumor extent, adjuvant therapy, tumor DNA ploidy, and S-phase fraction) that could be determined before operation were useful in predicting survival in patients undergoing pelvic exenteration for rectal cancer.
  
  
  METHODS
  Between 1983 and 1992, 40 patients (15 male and 25 female) at our institution underwent pelvic exenteration for rectal adenocarcinoma in which tumor-free pathologic margins were obtained. Twenty-nine patients presented with primary tumors; 11 had recurrent disease. A total exenteration was performed in 20 patients, posterior exenteration in 18 patients, and an anterior exenteration in 2 patients.
  
  
  RESULTS
  By multivariate (Cox proportional hazards regression) analysis, age, preoperative chemoradiation therapy, and an S phase of 10% or greater were found to be significant predictors of survival. Age older than 55 years was associated with a relative risk for cancer-related death (RR) of 0.13 (p = 0.02), and chemoradiation had an RR of 0.05 (p = 0.01), indicating their beneficial effect. An S-phase fraction of 10% or greater had an RR of 16.97 (p = 0.03), indicating a poor survival. The clinicopathologic factors listed above were used to derive a prognostic index (PI). A PI of less than 1.37 was associated with a 5-year survival rate of 65% (low risk), whereas patients with a PI of 1.37 or greater had a 5-year survival rate of 20% (high risk) (p = 0.005).
  
  
  CONCLUSIONS
  These results indicate that adjuvant chemoradiation may significantly improve survival in patients who require pelvic exenteration for resection of locally advanced rectal carcinoma. An S-phase fraction of 10% or greater is also predictive of a poor outcome. Use of these factors allowed the generation of a PI that identifies high- and low-risk patients. Consideration of the ability to deliver chemoradiation and the determinates of the tumor S-phase fraction in patients requiring pelvic exenteration for rectal cancer may be helpful in predicting outcome and planning therapy.
authors.affiliation: Department of Surgical Oncology, University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Meterissian
authors.forename: J M
authors.initials: JM
authors.lastname: Skibber
authors.forename: G G
authors.initials: GG
authors.lastname: Giacco
authors.forename: A K
authors.initials: AK
authors.lastname: el-Naggar
authors.forename: K R
authors.initials: KR
authors.lastname: Hess
authors.forename: T A
authors.initials: TA
authors.lastname: Rich
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010385:Pelvic Exenteration; D011003:Ploidies; D011237:Predictive Value of Tests; D011379:Prognosis; D012004:Rectal Neoplasms / Q000235:genetics / Q000401:mortality / Q000473:pathology / Q000601:surgery* / Q000628:therapy; D012189:Retrospective Studies; D015996:Survival Rate