title: The effect of carbohydrate restriction on prostate cancer tumor growth in a castrate mouse xenograft model.
abstract: BACKGROUND
  No- and low-carbohydrate diets delay tumor growth compared to western diet (WD) in prostate cancer (PCa) xenograft studies. The effect of these diets in concert with androgen deprivation is unknown.
  
  
  METHODS
  A total of 160 male SCID mice were injected with 1× 10(5) LAPC-4 human PCa cells. Of these, 150 mice were castrated and randomized to an ad libitum WD or fed via a paired-feeding protocol with a no-carbohydrate ketogenic diet (NCKD), 10% carbohydrate diet, or 20% carbohydrate diet. The remaining 10 mice were not castrated and were fed an ad libitum WD. The mice were sacrificed once volumes reached 1,000 mm3 and survival tested using the log-rank test. Serum from the median surviving 8 mice/group was assayed for insulin, IGF-1, and IGFBP-3.
  
  
  RESULTS
  Body weights were roughly equal among groups. The 10 non-castrated mice experienced accelerated tumor growth. Among castrated mice, WD had the most rapid tumor growth; 20% carbohydrate diet the slowest (P = 0.046). Survival was not significantly different among the various carbohydrate restricted groups (P = 0.51). When pooled, there was a non-significant trend (P = 0.11) in improved survival among the carbohydrate restricted diets versus WD. No significant difference in serum insulin, IGF-1, and IGFBP-3 levels was noted among all groups at pre-randomization or at sacrifice.
  
  
  CONCLUSIONS
  A 20% carbohydrate diet slowed tumor growth versus a WD. Though the benefit of carbohydrate restriction was somewhat less than in prior studies in non-castrate mice, these data still suggest diets achievable in humans may play a role in PCa management.
authors.affiliation: Division of Urologic Surgery, Duke Prostate Center, Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710, USA.
authors.forename: Jorge
authors.initials: J
authors.lastname: Caso
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Masko
authors.forename: Jean A Thomas
authors.initials: JA
authors.lastname: Ii
authors.forename: Susan H
authors.initials: SH
authors.lastname: Poulton
authors.forename: Mark
authors.initials: M
authors.lastname: Dewhirst
authors.forename: Salvatore V
authors.initials: SV
authors.lastname: Pizzo
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
mesh_terms: D000728:Androgens / Q000172:deficiency; D000821:Animal Feed; D000818:Animals; D045744:Cell Line, Tumor; D050528:Diet, Carbohydrate-Restricted; D055423:Diet, Ketogenic; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D002149:Energy Intake / Q000502:physiology; D006801:Humans; D007328:Insulin / Q000097:blood; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D008297:Male; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D009919:Orchiectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000178:diet therapy* / Q000401:mortality / Q000473:pathology; D011897:Random Allocation; D023041:Xenograft Model Antitumor Assays
chemical_list: D000728:Androgens; D004040:Dietary Carbohydrates; D007328:Insulin; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I