Identification and validation of a multigene predictor of recurrence in primary laryngeal cancer.
OBJECTIVE
Local recurrence is the major manifestation of treatment failure in patients with operable laryngeal carcinoma. Established clinicopathological factors cannot sufficiently predict patients that are likely to recur after treatment. Additional tools are therefore required to accurately identify patients at high risk for recurrence. This study attempts to identify and independently validate gene expression models, prognostic of disease-free survival (DFS) in operable laryngeal cancer.


METHODS
Using Affymetrix U133A Genechips, we profiled fresh-frozen tumor tissues from 66 patients with laryngeal cancer treated locally with surgery. We applied Cox regression proportional hazards modeling to identify multigene predictors of recurrence. Gene models were then validated in two independent cohorts of 54 and 187 patients (fresh-frozen and formalin-fixed tissue validation sets, respectively).


RESULTS
We focused on genes univariately associated with DFS (p<0.01) in the training set. Among several models comprising different numbers of genes, a 30-probe set model demonstrated optimal performance in both the training (log-rank, p<0.001) and 1(st) validation (p=0.010) sets. Specifically, in the 1(st) validation set, median DFS as predicted by the 30-probe set model, was 34 and 80 months for high- and low-risk patients, respectively. Hazard ratio (HR) for recurrence in the high-risk group was 3.87 (95% CI 1.28-11.73, Wald's p=0.017). Testing the expression of selected genes from the above model in the 2(nd) validation set, with qPCR, revealed significant associations of single markers, such as ACE2, FLOT1 and PRKD1, with patient DFS. High PRKD1 remained an unfavorable prognostic marker upon multivariate analysis (HR=2.00, 95% CI 1.28-3.14, p=0.002) along with positive nodal status.


CONCLUSIONS
We have established and validated gene models that can successfully stratify patients with laryngeal cancer, based on their risk for recurrence. It seems worthy to prospectively validate PRKD1 expression as a laryngeal cancer prognostic marker, for routine clinical applications.
Department of Medical Oncology, "Papageorgiou" Hospital, Aristotle University of Thessaloniki School of Medicine, Thessaloniki, Greece. elenafou@gmail.com
Elena
E
Fountzilas
Vassiliki
V
Kotoula
Nikolaos
N
Angouridakis
Ilias
I
Karasmanis
Ralph M
RM
Wirtz
Anastasia G
AG
Eleftheraki
Elke
E
Veltrup
Konstantinos
K
Markou
Angelos
A
Nikolaou
Dimitrios
D
Pectasides
George
G
Fountzilas
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000085962:Angiotensin-Converting Enzyme 2; D014408:Biomarkers, Tumor / Q000235:genetics*; D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007822:Laryngeal Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D007830:Larynx / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D008137:Longitudinal Studies; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality / Q000601:surgery; D007703:Peptidyl-Dipeptidase A / Q000235:genetics; D011379:Prognosis; D016016:Proportional Hazards Models; D011493:Protein Kinase C / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D014408:Biomarkers, Tumor; D008565:Membrane Proteins; C106354:flotillins; C089212:protein kinase D; D011493:Protein Kinase C; D007703:Peptidyl-Dipeptidase A; C000705307:ACE2 protein, human; D000085962:Angiotensin-Converting Enzyme 2