title: REOX: Evaluation of the Efficacy of Retreatment With an Oxaliplatin-containing Regimen in Metastatic Colorectal Cancer: A Retrospective Single-center Study.
abstract: Treatment of metastatic colorectal adenocarcinoma (mCRC) has evolved, and survival is over 30 months in contemporary trials. Nevertheless, there is a paucity of effective regimes after the first or second-line treatment. Thus, reexposure to previously used drugs has become a treatment strategy for some patients. We aimed to evaluate the efficacy of retreatment with an oxaliplatin-containing regimen in mCRC and correlate this with clinicopathologic features.
  
  
  
  We retrospectively analyzed 83 patients with mCRC who underwent reexposure to oxaliplatin (REOX). REOX was defined as a second trial of an oxaliplatin-containing regimen after a previous failure. Primary endpoint was time to treatment failure (TTF).
  
  
  
  The median age was 53.5 years, and the female/male ratio was 51.8%/48.2%. The site of the primary tumor was colon (67.5%) and rectal (32.5%). KRAS was mutated in 39.8%. Liver-limited metastasis was found in 19.3% of patients. The main regimen was 5-fluorouracil, levoleucovorin, and oxaliplatin (mFOLFOX6) (84.3%). Bevacizumab and cetuximab were used in 42.2% and 6% of patients, respectively. REOX was used in the third and fourth lines in 48.2% and 25.3% of patients, respectively. The median TTF after REOX was 6.04 months. Overall survival (OS) was 10.04 months. Disease control (complete response + partial response + stable disease) was observed in 56.6%, whereas 42.2% had progressive disease. Partial response + complete response to previous oxaliplatin was predictive of prolonged OS. Patients who attained disease control had better median OS compared with those with progressive disease (14.5 vs. 6.24 months; P < .0001).
  
  
  
  In the setting of heavily pretreated patients with mCRC, REOX was an effective treatment, with mTTF of 6.04 months in our cohort. Selection of patients with the longest time since previous oxaliplatin can translate in better outcome. Further studies should be conducted to confirm our data.
authors.affiliation: Department of Medical Oncology, AC Camargo Cancer Center, Sao Paulo, Brazil.
authors.forename: Talita
authors.initials: T
authors.lastname: Costa
authors.affiliation: Department of Medical Oncology, AC Camargo Cancer Center, Sao Paulo, Brazil.
authors.forename: Jose
authors.initials: J
authors.lastname: Nuñez
authors.affiliation: Department of Medical Oncology, AC Camargo Cancer Center, Sao Paulo, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Felismino
authors.affiliation: Department of Medical Oncology, AC Camargo Cancer Center, Sao Paulo, Brazil.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Boente
authors.affiliation: Department of Medical Oncology, AC Camargo Cancer Center, Sao Paulo, Brazil. Electronic address: celso.almello@gmail.com.
authors.forename: Celso
authors.initials: C
authors.lastname: Mello
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009944:Organoplatinum Compounds / Q000008:administration & dosage; D000077150:Oxaliplatin; D018579:Patient Selection; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D019233:Retreatment; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: C117307:KRAS protein, human; D009944:Organoplatinum Compounds; D000077150:Oxaliplatin; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Colorectal carcinoma; Oxaliplatin; Prognosis; Re-challenge; Treatment