Clinical and immunological characteristics of patients with serologic progression of prostate cancer achieving long-term disease control with granulocyte-macrophage colony-stimulating factor.
OBJECTIVE
We describe the clinical and immunological characteristics of patients with biochemically relapsed prostate cancer who achieved long-term disease control with GM-CSF (Leukine).


METHODS
A total of 30 patients with prostate cancer and nonmetastatic recurrent disease, as manifested by increasing PSA between 0.4 and 6.0 ng/ml after prior definitive therapy, were enrolled in a phase II trial. Patients received 250 microg/m2 GM-CSF daily subcutaneously on days 1 through 14 of a 28-day cycle until PSA or objective progression. The patient and disease characteristics of patients who remained without evidence of disease progression beyond 4 years were examined. Additionally, flow cytometry was performed in peripheral blood to characterize monocyte and dendritic cells.


RESULTS
Seven of 29 evaluable patients (24%) remained free of disease progression at a median of 5.1 years (range 4.5 to 5.6 or greater) from the start of GM-CSF therapy. Patients on long-term GM-CSF tended to have lower initial T stage, Gleason score and pretreatment PSA. An increase in the number of circulating monocytes and dendritic cells was observed after 14 days of GM-CSF treatment. These values returned to baseline during the 14-day off period.


CONCLUSIONS
GM-CSF modulates PSA in androgen dependent, biochemically relapsed cases. A substantial proportion of patients achieve long-term disease control. The clinical characteristics described may help select patients for future clinical trials with GM-CSF or other immunomodulators. Additional investigation is required to define the immunological mechanism of GM-CSF in prostate cancer.
Rini
Brian I
BI
University of California-San Francisco Comprehensive Cancer Center, San Francisco, California, USA. rinib2@ccf.org
Fong
Lawrence
L
Weinberg
Vivian
V
Kavanaugh
Brian
B
Small
Eric J
EJ
D000368:Aged; D018450:Disease Progression; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000276:immunology* / Q000517:prevention & control*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000276:immunology* / Q000517:prevention & control*; D011994:Recombinant Proteins; D013997:Time Factors
D011994:Recombinant Proteins; C081222:sargramostim; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D017430:Prostate-Specific Antigen