Tumor and Plasma Met Levels in Non-Metastatic Prostate Cancer.
OBJECTIVE
To measure Met protein content in prostate biopsies guided by fused magnetic resonance and ultrasound imaging, and to measure soluble Met (sMet) protein concentration in plasma samples from patients presenting evidence of prostate cancer.


METHODS
345 patients had plasma samples drawn prior to image-guided biopsy of the prostate. Of these, 32% had benign biopsies. Of the 236 that were positive for prostate adenocarcinoma (PCa), 132 treated by total prostatectomy had Gleason scores of 6 (17%), 7, (55%), 8 (16%), or 9-10 (12%). 23% had evidence of local invasion. Plasma samples were also obtained from 80 healthy volunteers. Tissue Met and plasma sMet were measured by two-site immunoassay; values were compared among clinically defined groups using non-parametric statistical tests to determine significant differences or correlations.


RESULTS
PCa tumor Met correlated significantly with plasma sMet, but median values were similar among benign and malignant groups. Median plasma sMet values were also similar among those groups, although both medians were significantly above normal. Median Met content in primary PCa tumors and sMet concentrations were independent of Gleason score, final pathologic stage and age.


CONCLUSIONS
Plasma sMet is not predictive of PCa or its severity in patients with organ-confined or locally invasive disease. Quantitative analysis of Met protein content and activation state in PCa tumor biopsy samples was highly feasible and may have value in follow-up to genomic and/or transcriptomic-based screens that show evidence of oncogenically relevant MET gene features that occur at relatively low frequency in non-metastatic PCa.
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Deborah R
DR
Kaye
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Peter A
PA
Pinto
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Fabiola
F
Cecchi
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Joseph
J
Reilly
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Alice
A
Semerjian
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Daniel C
DC
Rabe
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Gopal
G
Gupta
Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Peter L
PL
Choyke
Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD, 20892, United States of America.
Donald P
http://orcid.org/0000-0002-5057-5334
DP
Bottaro
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D061705:Image-Guided Biopsy; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011467:Prostate / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis / Q000473:pathology*; D019859:Proto-Oncogene Proteins c-met / Q000032:analysis* / Q000097:blood*
C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met