title: Upregulated Polo-Like Kinase 1 Expression Correlates with Inferior Survival Outcomes in Rectal Cancer.
abstract: BACKGROUND
  Human polo-like kinase 1 (PLK1) expression has been associated with inferior outcomes in colorectal cancer. Our aims were to analyse PLK1 in rectal cancer, and its association with clinicopathological variables, overall survival as well as tumour regression to neoadjuvant treatment.
  
  
  METHODS
  PLK1 expression was quantified with immunohistochemistry in the centre and periphery (invasive front) of rectal cancers, as well as in the involved regional lymph nodes from 286 patients. Scores were based on staining intensity and percentage of positive cells, multiplied to give weighted scores from 1-12, dichotomised into low (0-5) or high (6-12).
  
  
  RESULTS
  PLK1 scores in the tumour periphery were significantly different to adjacent normal mucosa. Survival analysis revealed that low PLK1 score in the tumour periphery had a hazard ratio of death of 0.59 in multivariate analysis. Other predictors of survival included age, tumour depth, metastatic status, vascular and perineural invasion and adjuvant chemotherapy. There was no statistically significant correlation between PLK1 score and histological tumour regression in the neoadjuvant cohort.
  
  
  CONCLUSIONS
  Low PLK1 score was an independent predictor of superior overall survival, adjusting for multiple clinicopathological variables including treatment.
authors.affiliation: School of Medicine, University of Western Sydney, Liverpool, New South Wales 2170, Australia; Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia.
authors.forename: T G
authors.initials: TG
authors.lastname: Tut
authors.affiliation: Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; University of New South Wales, Kensington, New South Wales 2052, Australia; Department of Medical Oncology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia.
authors.forename: S H S
authors.initials: SH
authors.lastname: Lim
authors.affiliation: School of Medicine, University of Western Sydney, Liverpool, New South Wales 2170, Australia; Department of Anatomical Pathology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia.
authors.forename: I U
authors.initials: IU
authors.lastname: Dissanayake
authors.affiliation: Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; University of New South Wales, Kensington, New South Wales 2052, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Descallar
authors.affiliation: Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; Department of Medical Oncology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Chua
authors.affiliation: Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; Department of Medical Oncology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia.
authors.forename: W
authors.initials: W
authors.lastname: Ng
authors.affiliation: School of Medicine, University of Western Sydney, Liverpool, New South Wales 2170, Australia; Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; University of New South Wales, Kensington, New South Wales 2052, Australia; Department of Medical Oncology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia.
authors.forename: P
authors.initials: P
authors.lastname: de Souza
authors.affiliation: School of Medicine, University of Western Sydney, Liverpool, New South Wales 2170, Australia; Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; Department of Anatomical Pathology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia.
authors.forename: J-S
authors.initials: JS
authors.lastname: Shin
authors.affiliation: School of Medicine, University of Western Sydney, Liverpool, New South Wales 2170, Australia; Ingham Institute for Applied Medical Research, Liverpool, New South Wales 2170, Australia; University of New South Wales, Kensington, New South Wales 2052, Australia; Department of Anatomical Pathology, Liverpool Hospital, Liverpool, New South Wales 2170, Australia; Bosch Institute, University of Sydney, Camperdown, New South Wales 2006, Australia.
authors.forename: C S
authors.initials: CS
authors.lastname: Lee
mesh_terms: D000368:Aged; D018797:Cell Cycle Proteins / Q000378:metabolism*; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy / Q000379:methods; D009367:Neoplasm Staging; D017063:Outcome Assessment, Health Care / Q000379:methods* / Q000706:statistics & numerical data; D011379:Prognosis; D016016:Proportional Hazards Models; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D016019:Survival Analysis; D015854:Up-Regulation; D000097869:Polo-Like Kinase 1
chemical_list: D018797:Cell Cycle Proteins; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D000097869:Polo-Like Kinase 1