The influence of the pituitary tumor transforming gene-1 (PTTG-1) on survival of patients with small cell lung cancer and non-small cell lung cancer.
BACKGROUND
PTTG-1 (pituitary tumor transforming gene) is a novel oncogene that is overexpressed in tumors, such as pituitary adenoma, breast and gastrointestinal cancers as well as in leukemia. In this study, we examined the role of PTTG-1 expression in lung cancer with regard to histological subtype, the correlation of PTTG-1 to clinical parameters and relation on patients' survival.


METHODS
Expression of PTTG-1 was examined immunohistochemically on formalin-fixed, paraffin-embedded tissue sections of 136 patients with small cell lung cancer (SCLC) and 91 patients with non-small cell lung cancer (NSCLC), retrospectively. The intensity of PTTG-1 expression as well as the proportion of PTTG-1 positive cells within a tumor was used for univariate and multivariate analysis.


RESULTS
PTTG-1 expression was observed in 64% of SCLC tumors and in 97.8% of NSCLC tumors. In patients with SCLC, negative or low PTTG-1 expression was associated with a shorter mean survival time compared with patients with strong PTTG-1 expression (265 +/- 18 days vs. 379 +/- 66 days; p = 0.0291). Using the Cox regression model for multivariate analysis, PTTG-1 expression was a significant predictor for survival next to performance status, tumor stage, LDH and hemoglobin. In contrast, in patients with NSCLC an inverse correlation between survival and PTTG-1 expression was seen. Strong PTTG-1 expression was associated with a shorter mean survival of 306 +/- 58 days compared with 463 +/- 55 days for those patients with no or low PTTG-1 intensities (p = 0.0386). Further, PTTG-1 expression was associated with a more aggressive NSCLC phenotype with an advanced pathological stage, extensive lymph node metastases, distant metastases and increased LDH level. Multivariate analysis using Cox regression confirmed the prognostic relevance of PTTG-1 expression next to performance status and tumor stage in patients with NSCLC.


CONCLUSIONS
Lung cancers belong to the group of tumors expressing PTTG-1. Dependent on the histological subtype of lung cancer, PTTG-1 expression was associated with a better outcome in patients with SCLC and a rather unfavourable outcome for patients with NSCLCs. These results may reflect the varying role of PTTG-1 in the pathophysiology of the different histological subtypes of lung cancer.
Rehfeld
Nina
N
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Geddert
Helene
H
Institut für Pathologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Atamna
Abedelsalam
A
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Rohrbeck
Astrid
A
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Garcia
Guillermo
G
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Kliszewski
Slawek
S
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Neukirchen
Judith
J
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Bruns
Ingmar
I
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Steidl
Ulrich
U
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Fenk
Roland
R
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Gabbert
Helmut E
HE
Institut für Pathologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Kronenwett
Ralf
R
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Haas
Rainer
R
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.
Rohr
Ulrich-Peter
UP
Klinik für Hämatologie, Onkologie und klinische Immunologie, Heinrich-Heine-Universität Düsseldorf, Moorenstraße 5, D-40225 Düsseldorf, Germany.