title: Phase II, open-label trial of single-agent CCNU in dogs with previously untreated histiocytic sarcoma.
abstract: BACKGROUND
  Histiocytic sarcoma (HS) is an aggressive neoplasm in dogs, and in most instances, the disease is localized, but not amenable to surgical removal, or is disseminated. Affected patients usually die within 6 months. There have been no prospective studies to determine efficacy of single-agent chemotherapy in dogs with HS.
  
  
  OBJECTIVE
  Single-agent CCNU [1-(2-chloroethyl)3-cyclohexyl-1-nitrosourea; lomustine] has antitumor activity against HS in dogs.
  
  
  METHODS
  Twenty-one dogs with histologically confirmed, nonresectable localized or disseminated HS.
  
  
  METHODS
  Prospective, open-label phase II clinical trial in which dogs with previously untreated HS were uniformly treated with CCNU as a single oral dosage of 90 mg/m2 every 4 weeks. The primary outcome measure was reduction in tumor size.
  
  
  RESULTS
  Fourteen dogs with disseminated HS and 7 with localized HS were enrolled between 1999 and 2008. Overall response rate was 29% (95% confidence interval [CI], 14–50%) for a median of 96 days (95% CI, 55–137 days). Three dogs (1 disseminated, 2 localized) had complete responses lasting for 54–269 days and 3 dogs (2 disseminated, 1 localized) had partial responses lasting for 78–112 days.
  
  
  CONCLUSIONS
  CCNU, when used as a single agent, has activity against HS in dogs. Evaluation of CCNU postoperatively for dogs with resectable localized HS and as part of combination therapy for tumors that are nonresectable or disseminated should be considered.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA. kmr32@cornell.edu
authors.forename: K M
authors.initials: KM
authors.lastname: Rassnick
authors.forename: A S
authors.initials: AS
authors.lastname: Moore
authors.forename: D S
authors.initials: DS
authors.lastname: Russell
authors.forename: N C
authors.initials: NC
authors.lastname: Northrup
authors.forename: O
authors.initials: O
authors.lastname: Kristal
authors.forename: D B
authors.initials: DB
authors.lastname: Bailey
authors.forename: A B
authors.initials: AB
authors.lastname: Flory
authors.forename: M A
authors.initials: MA
authors.lastname: Kiselow
authors.forename: J L
authors.initials: JL
authors.lastname: Intile
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D005260:Female; D054747:Histiocytic Sarcoma / Q000188:drug therapy / Q000662:veterinary*; D008130:Lomustine / Q000008:administration & dosage / Q000627:therapeutic use*; D008297:Male
chemical_list: D000970:Antineoplastic Agents; D008130:Lomustine