Insulin-like growth factor (IGF) 1 and 2 help to predict disease outcome in GIST patients.
BACKGROUND
The expression of the insulin-like growth factor (IGF) system has never been studied in gastrointestinal stromal tumors (GISTs).


METHODS
We studied the immunohistochemical expression of IGF1 receptor (IGFR-I), IGF1 and IGF2 in 94 samples of GISTs. IGF1 and IGF2 expression was scored in three classes: negative (N), moderate (M) and strong (S), according to staining intensity and extent.


RESULTS
IGFR-I was overexpressed in all cases. IGF1 and IGF2 expression was absent in 25 and 48 cases, moderate in 29 and 16 cases and strong in 40 and 30 cases, respectively. Strong IGF1 expression significantly correlated with higher mitotic index (P = 0.0001), larger (P = 0.01), higher risk (P = 0.0002), metastatic (P = 0.0001) and relapsed (P = 0.04) GISTs. Strong IGF2 expression correlated with higher mitotic index (P = 0.05) and higher risk GISTs (P = 0.001). The Kaplan-Meier analysis (N versus M versus S) showed a significant worsening of the disease-free survival (DFS) with the increase of IGF1 (P = 0.02) and IGF2 (P = 0.02) expression. In the subgroup of patients with operated high-risk GISTs, there was a better trend in DFS for patients affected by GISTs with negative IGF1 and IGF2.


CONCLUSIONS
The expression of IGF1 and IGF2 seems to predict relapse in GIST patients.
Braconi
C
C
Centro Regionale di Genetica Oncologica-Oncologia Medica, Università Politecnica delle Marche. Electronic address: chiarabraconi@tiscali.it.
Bracci
R
R
Centro Regionale di Genetica Oncologica-Oncologia Medica, Università Politecnica delle Marche; Clinica di Oncologia Medica, Ospedali Riuniti Ancona.
Bearzi
I
I
Anatomia ed Istologia Patologica.
Bianchi
F
F
Centro Regionale di Genetica Oncologica-Oncologia Medica, Università Politecnica delle Marche.
Sabato
S
S
Anatomia ed Istologia Patologica.
Mandolesi
A
A
Anatomia ed Istologia Patologica.
Belvederesi
L
L
Centro Regionale di Genetica Oncologica-Oncologia Medica, Università Politecnica delle Marche.
Cascinu
S
S
Clinica di Oncologia Medica, Ospedali Riuniti Ancona.
Valeri
N
N
Scuola di Specializzazione in Oncologia, Università Politecnica delle Marche, Ancona, Italy.
Cellerino
R
R
Centro Regionale di Genetica Oncologica-Oncologia Medica, Università Politecnica delle Marche.
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005455:Fluorescent Antibody Technique; D046152:Gastrointestinal Stromal Tumors / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D007334:Insulin-Like Growth Factor I / Q000235:genetics / Q000378:metabolism*; D007335:Insulin-Like Growth Factor II / Q000235:genetics / Q000378:metabolism*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D012008:Recurrence; D047368:Tumor Burden
D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D019009:Proto-Oncogene Proteins c-kit; D017526:Receptor, IGF Type 1