Μοριακοί προγνωστικοί δείκτες στον καρκίνο ωοθηκών

Abstract

Purpose: Traditional clinopathologic factors do not accurately classify ovarian cancer patients in relation to outcome. Several molecular markers have been evaluated for their prognostic value in ovarian cancer patients using conventional immunohistochemistry. However, different methods of immunohistochemical assessment have yielded conflicting results. Here, we sought to determine the prognostic value of a series of biomarkers in ovarian cancer using a novel method of compartmentalized in- situ protein analysis (AQUA). Methods: A tissue array composed of 150 advanced stage ovarian cancers uniformly treated, with surgical debulking followed by platinum-paclitaxel combination chemotherapy, was constructed. For evaluation of protein expression, we used an immunofluorescence-based method of automated in-situ quantitative measurement of protein analysis (AQUA). The following proteins were studied: p53, p27, p21, p16, pRb, p73, cyclin D1, EGFR, pAkt, PTEN, β-catenin, DCC, kallikreins 6,7,8. Results: The mean follow-up time of the patients was 34.3 months. Patients with low FIGO stage were more likely to have low nuclear p27 expression (p=0.008). Low nuclear p27 expression was associated with improved 3-year overall survival (66% versus 20%, p=0.0047) and disease-free survival (27% versus 12%, p=0.022). In multivariable analysis, adjusting for well-characterized prognostic variables, low nuclear p27 expression level was the most significant prognostic factor for both disease-free and overall survival. High tumor EGFR expression was associated with poor outcome for overall survival (p=0.0001) and disease-free survival (p=0.0005) at 3 years. In multivariable analysis, adjusting for well-characterized prognostic variables, EGFR expression status was the most significant prognostic factor for disease-free and overall survival. Analysis of cIAP and pAkt showed that there was a significant relationship between tumors phospho-Akt_tum expression and cLAP_membraneous expression (p=0.035). Patients with high ciap membraneous expression had an overall survival rate of 31% compared with 73% for patients with low cIAP tumors (p=0.0020). Univariate Cox regression revealed a hazard ratio (HR) for high CIAP tumors of 3.0 (p=0.002). Patients with tumors bearing low nuclear DCC expression had a 3-year progression-free survival rate of 0% compared with those with high DCC bearing tumors (p=0.0067). In multivariable analysis, adjusting for well-characterized prognostic variables, low nuclear DCC expression level retained its prognostic significance for progression-free survival. Between DCC and β-catenin a significant relationship was found, where tumors with low DCC had low β-catenin and vice versa (p=0.003). High nuclear p53 levels were associated with improved overall survival (p=0.0132). Conclusions: Our results indicate that quantitative assessment of protein expression level by automated in situ quantitative analysis (AUA) can accurately classify ovarian cancer patients in terms of prognosis and identify molecular targets for therapy in ovarian cancer.

[…] Σκοπός της παρούσας διδακτορικής διατριβής ήταν η ανεύρεση μοριακών δεικτών που σχετίζονται με την πρόγνωση ασθενών με καρκίνο ωοθηκών προχωρημένου σταδίου. Για να αποφευχθούν τα σφάλματα που σχετίζονται με τη χρήση της συμβατικής ανοσοϊστοχημείας, χρησιμοποιήσαμε την νέα τεχνική AQUA σε ιστική μικροσυστοιχία αποτελούμενη από ωοθηκικούς όγκους. Η AQUA είναι ένα σύνολο αλγόριθμων που επιτρέπουν την ταχεία, αυτόματη, συνεχή και ποσοτική ανάλυση πρωτεϊνών σε ιστικές μικροσυστοιχίες. Η μέθοδος αυτή επίσης επιτρέπει τον διαχωρισμό των καρκινικών κυττάρων από τον περιβάλλοντα συνδετικό ιστό και τον εντοπισμό του «σήματος» ανά κυτταρικό υποτμήμα. Η τεχνική αυτή έχει επαληθευτεί με την μελέτη των υποδοχέων οιστρογόνων σε καρκίνο μαστού η οποία έδειξε ότι η AQUA υπερτερεί των αποτελεσμάτων που ελήφθησαν με τη συμβατική ανοσοϊστοχημική μέθοδο. […]