title: Prognostic implications of PIK3CA amplification in curatively resected liposarcoma.
abstract: BACKGROUND
  We investigated the epidemiologic characteristics and prognostic significance of PIK3CA mutations/amplifications in curative resected liposarcoma.
  
  
  METHODS
  A total of 125 liposarcoma tissue samples were collected over a 12-year period. PIK3CA mutations and gene copy number amplifications were analyzed by pyrosequencing and fluorescence in situ hybridization (FISH).
  
  
  RESULTS
  Nine of the 105 liposarcomas (8.6%) had activating PIK3CA mutation. PIK3CA mutations were more frequent in myxoid/round cell and pleomorphic tumors compared with well-differentiated/dedifferentiated tumors (13.3% vs. 2.2%, P=0.043). In FISH PIK3CA analysis, copy number gain was detected in 14 of the 101 tumors (13.9%): 11 (10.9%) tumors had increased gene copy number (polysomy) and 3 (3.0%) exhibited gene amplification. In survival analysis, patients with PIK3CA copy number gain had a worse prognosis compared to patients without PIK3CA amplification (median disease-free survival [DFS] 22.2 vs. 107.6 months p=0.005). By multivariate analysis, PIK3CA copy number gain was an independent prognostic factor for worse DFS (P=0.027; hazard ratio, 2.400; 95% confidence interval 1.105 to 5.213). PIK3CA mutation was not associated with DFS and overall survival.
  
  
  CONCLUSIONS
  We demonstrated PIK3CA mutation and amplification in liposarcoma. PIK3CA copy number gain was an independent poor prognostic factor for DFS. Further studies are needed to evaluate the potential diagnostic and therapeutic role of PIK3CA mutations and amplifications in liposarcoma.
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Joo Hoon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Pathology, Dongguk University College of Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
authors.forename: Jae Seok
authors.initials: JS
authors.lastname: Lee
authors.affiliation: Department of Pathology, Dongguk University College of Medicine, Dongguk University Ilsan Hospital, Goyang, Korea.
authors.forename: Eo Jin
authors.initials: EJ
authors.lastname: Kim
authors.affiliation: Cancer Metastasis Research Center, Song Dang Institute for Cancer Research, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyu Hyun
authors.initials: KH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Ki Hyang
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Ilsan Paik Hospital, Inje University College of Medicine, Ilsan, Korea.
authors.forename: Seong Yoon
authors.initials: SY
authors.lastname: Yi
authors.affiliation: Department of Pathology, Ilsan Paik Hospital, Inje University College of Medicine, Ilsan, Korea.
authors.forename: Han Seong
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Orthopedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Yong Jin
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: Department of Orthopedic Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyoo-Ho
authors.initials: KH
authors.lastname: Shin
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Joong Bae
authors.initials: JB
authors.lastname: Ahn
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Hu
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kyung Sik
authors.initials: KS
authors.lastname: Kim
authors.affiliation: Department of Urology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Deuk
authors.initials: YD
authors.lastname: Choi
authors.affiliation: Department of Obstetrics and Gynecology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sunghoon
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jin-Suck
authors.initials: JS
authors.lastname: Suh
authors.affiliation: Department of Surgery, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Noh
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Sun Young
authors.initials: SY
authors.lastname: Rha
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Yonsei Cancer Center, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hyo Song
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D058534:Class I Phosphatidylinositol 3-Kinases / Q000235:genetics*; D056915:DNA Copy Number Variations; D005260:Female; D005784:Gene Amplification; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D053208:Kaplan-Meier Estimate; D008080:Liposarcoma / Q000175:diagnosis / Q000235:genetics* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011379:Prognosis; D055815:Young Adult
chemical_list: D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human
keywords: PIK3CA; amplification; liposarcoma; mutation