title: Analyses of multiple factors for determination of "selected patients" who should receive rechallenge treatment in metastatic colorectal cancer: a retrospective study from Turkey.
abstract: BACKGROUND
  Repeating a prior chemotherapy (rechallenge therapy) is an option for selected patients with metastatic colorectal cancer, but there is very little evidence in the literature for this approach. Thus, we reviewed our registry to evaluate prognostic factors and survival of patients who received irinotecan and oxaliplatin- based regimens as rechallenge third and fourth-line therapy.
  
  
  METHODS
  Patients who received irinotecan-based or oxaliplatin-base regimen as first-line had been rechallenged with third-line or fourth-line therapy. These patients were selected from the database of Turkish mCRC registry archives between October 2006 and June 2013 and evaluated retrospectively for factors effecting progression free survival (PFS) and overall survival (OS) by the Kaplan-Meir and Cox-regression methods.
  
  
  RESULTS
  Thirty-nine patients were enrolled. The median duration of follow-up was 36 months (14-68 months). Thirty-one patients (76%) died during follow-up. In terms of rechallenge treatments, 29 patients had received third-line and 10 patients had received fourth-line. Response rate (RR) was found to be 12.9%, with stable disease in 19 (48.7%) patients. The median PFS was 6 months (95%CI=4.64-7.35 months) and the median OS was 11 months (95%CI=8.31-13.7 months). The factors effecting survival (PFS and OS) were only being PFS after first-line chemotherapy≥12 months (p=0.007, 95% CI=1.75-35.22 and p=0.004, 95%CI=1.44-7.11), both in univariate and multivariate analyses.
  
  
  CONCLUSIONS
  This study indicates that rechallenge treatment could be a good option as a third or later line therapy in patients who had ≥12 months PFS on receiving first line therapy.
authors: Department of Medical Oncology, Erciyes University Faculty of Medicine, Kayseri, Turkey E-mail : dr-ozaslan@hotmail.com.
authors: Ersin
authors: E
authors: Ozaslan
authors: Ayse Ocak
authors: AO
authors: Duran
authors: Oktay
authors: O
authors: Bozkurt
authors: Mevlude
authors: M
authors: Inanc
authors: Mahmut
authors: M
authors: Ucar
authors: Veli
authors: V
authors: Berk
authors: Halit
authors: H
authors: Karaca
authors: Ferhan
authors: F
authors: Elmali
authors: Metin
authors: M
authors: Ozkan
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D000068258:Bevacizumab / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000032:analysis*; D002166:Camptothecin / Q000008:administration & dosage / Q000031:analogs & derivatives; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D000077146:Irinotecan; D002955:Leucovorin / Q000008:administration & dosage; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D018579:Patient Selection; D011379:Prognosis; D019233:Retreatment; D012189:Retrospective Studies; D015996:Survival Rate; D014421:Turkey
chemical_list: D014408:Biomarkers, Tumor; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D000068258:Bevacizumab; D000077146:Irinotecan; D002955:Leucovorin; D005472:Fluorouracil; D002166:Camptothecin