title: Relationship of postoperative thrombocytosis and survival of patients with colorectal cancer.
abstract: BACKGROUND
  Thrombocytosis accompanying solid tumors and predicting the prognosis of malignant tumors has been the subject of intensive research lately. Reports so far have evaluated the role of preoperative platelet count. In our present study we looked at the effect of tumor removal on platelet count and the predictive power of postoperative thrombocytosis on the survival of patients with colorectal cancer (CRC).
  
  
  METHODS
  We retrospectively evaluated the clinical and histopathological data of 336 patients operated due to CRC between 2001 and 2011. Thrombocytosis was defined as a platelet count exceeding 400 × 10(3)/μL. Preoperative platelet count was compared with the value measured 1 month postoperatively.
  
  
  RESULTS
  The platelet count significantly decreased after the removal of the primary tumor (paired Wilcoxon test p < 0.001). In univariate analysis preoperative thrombocytosis was a significant marker of overall survival (OS) with HR 2.2, p < 0.001 while the postoperative thrombocytosis was nearly significant with HR = 1.59, p = 0.087. In multivariate setting, when corrected for location, stage, tumor size and controlling for gender and age (> 65 years vs. ≤ 65 years), both pre- and postoperative thrombocytosis were significant independent prognostic markers with HR 1.80, p = 0.20 and HR = 1.98, p = 0.018, respectively.
  
  
  CONCLUSIONS
  Although the pathomechanism of thrombocytosis related to solid tumors is not known the decrease of platelet count after the removal of the primary tumor raises the possibility that the tumor may play an active role in the development of thrombocytosis. Furthermore, the observation of postoperative thrombocytosis with significant worse outcome underlines the predictive power of elevated platelet count.
authors.affiliation: Tumorgenetika Human Biospecimen Collection and Research Company, 1147 Budapest, Kerékgyártó utca 36-38, Hungary; Department of Otorhinolaryngology and Head and Neck Surgery, Flór Ferenc Hospital, 2143 Kistarcsa, Semmelweis tér 1, Hungary. Electronic address: josavaleria@gmail.com.
authors.forename: Valeria
authors.initials: V
authors.lastname: Josa
authors.affiliation: Department of Systems Biology, Technical University of Denmark, Kemitorvet, Building 208, 2800 Kgs. Lyngby, Denmark. Electronic address: marcin@cbs.dtu.dk.
authors.forename: Marcin
authors.initials: M
authors.lastname: Krzystanek
authors.affiliation: Department of Systems Biology, Technical University of Denmark, Kemitorvet, Building 208, 2800 Kgs. Lyngby, Denmark. Electronic address: eklund@cbs.dtu.dk.
authors.forename: Aron Charles
authors.initials: AC
authors.lastname: Eklund
authors.affiliation: Department of Pathology, Uzsoki Hospital, 1145 Budapest, Uzsoki utca 29-41, Hungary.
authors.forename: Ferenc
authors.initials: F
authors.lastname: Salamon
authors.affiliation: 1st Department of Surgery, Semmelweis University, 1082 Budapest, Üllői út 78, Hungary.
authors.forename: Attila
authors.initials: A
authors.lastname: Zarand
authors.affiliation: Department of Systems Biology, Technical University of Denmark, Kemitorvet, Building 208, 2800 Kgs. Lyngby, Denmark; Informatics Program, Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA; Molecular Oncology Research Group, MTA-SE/HAS-SU, Budapest, Hungary. Electronic address: Zoltan.Szallasi@childrens.harvard.edu.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Szallasi
authors.affiliation: Tumorgenetika Human Biospecimen Collection and Research Company, 1147 Budapest, Kerékgyártó utca 36-38, Hungary; 1st Department of Surgery, Semmelweis University, 1082 Budapest, Üllői út 78, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Baranyai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000150:complications / Q000401:mortality* / Q000601:surgery; D005260:Female; D006801:Humans; D006814:Hungary; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011183:Postoperative Complications / Q000209:etiology* / Q000401:mortality; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D013922:Thrombocytosis / Q000209:etiology* / Q000401:mortality
keywords: Colorectal cancer; Postoperative; Predictive marker; Survival; Thrombocytosis