title: Insulin-like growth factor-1 genotypes and haplotypes influence the survival of prostate cancer patients with bone metastasis at initial diagnosis.
abstract: BACKGROUND
  The insulin-like growth factor-1 (IGF-1) plays an important role in growth of prostate cancer (PCa) cells and facilitating the development and progression of PCa. This study aimed to evaluate the association of polymorphisms in three linkage disequilibrium (LD) blocks of the IGF-1 on the survival of metastatic PCa patients.
  
  
  METHODS
  A total of 215 patients with bone metastases at initial presentation were included in this study. The cytosine-adenine (CA) repeat polymorphism and rs12423791 were selected as representative polymorphisms in the LD blocks 1 and 2, respectively. Haplotype in the LD block 3 was analyzed using two tag single nucleotide polymorphisms (SNPs), rs6220 and rs7136446. Cancer-specific survival rate was estimated from the Kaplan-Meier curve, and the survival data were compared using the log-rank test.
  
  
  RESULTS
  Cancer-specific survival was significantly associated with the CA repeat polymorphism, rs12423791, and rs6220 (P = 0.013, 0.014, and 0.014, respectively). Although rs7136446 had no significant association with survival, the haplotype in the LD block 3 was significantly associated with cancer-specific survival (P = 0.0003). When the sum of the risk genetic factors in each LD block (19-repeat allele, C allele of rs12423791, or C-T haplotype) was considered, patients with all the risk factors had significantly shorter cancer specific-survival than those with 0-2 risk factors (P = 0.0003).
  
  
  CONCLUSIONS
  Polymorphisms in the IGF-1, especially a haplotype in the LD block 3, are assumed to be genetic markers predicting the outcome of metastatic PCa.
authors.affiliation: Department of Urology, Akita University Graduate School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
authors.forename: Norihiko
authors.initials: N
authors.lastname: Tsuchiya
authors.forename: Shintaro
authors.initials: S
authors.lastname: Narita
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Inoue
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Saito
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Numakura
authors.forename: Mingguo
authors.initials: M
authors.lastname: Huang
authors.forename: Shingo
authors.initials: S
authors.lastname: Hatakeyama
authors.forename: Shigeru
authors.initials: S
authors.lastname: Satoh
authors.forename: Seiichi
authors.initials: S
authors.lastname: Saito
authors.forename: Chikara
authors.initials: C
authors.lastname: Ohyama
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Arai
authors.forename: Osamu
authors.initials: O
authors.lastname: Ogawa
authors.forename: Tomonori
authors.initials: T
authors.lastname: Habuchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001859:Bone Neoplasms / Q000556:secondary*; D006239:Haplotypes; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D020641:Polymorphism, Single Nucleotide; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D012189:Retrospective Studies
chemical_list: D007334:Insulin-Like Growth Factor I