Effect of chemotherapy on somatostatin receptor detection with octreotide scintigraphy in hormone-refractory prostate cancer patients.
BACKGROUND
Neuroendocrine cells have been found in all stages of prostate cancer. Neuroendocrine differentiation of prostate adenocarcinoma is a possible target for therapeutic strategies, such as administration of GH analogs (e.g., somatostatin), especially in patients with hormone-refractory prostate cancer (HRPC). The presence of receptors for these drugs in tumor cells and tissues is essential and is assessed with 111In-octreotide scintigraphy (Octreoscan). The relationship between these receptors and chemotherapy, the new standard therapy for HRPC, is unknown.


METHODS
111In-octreotide scintigraphy was performed on 20 patients affected by HRPC, all with metastatic disease. Chemotherapy with a single agent was also administered to all patients.


RESULTS
In 63% of the patients, all metastases were negative to Octreoscan. Several metastases were positive in 37% of patients only, compared to 94% previously described in a chemotherapy-naive population.


CONCLUSIONS
Chemotherapy seemed to reduce the cellular receptors for somatostatin analogs.
Mencobonii
M
M
Oncology Unit, Villa Scassi Hospital, 16149 Genoa, Italy. manlio.mencoboni@fastwebnet.it
Tredici
S
S
Rebella
L
L
Bergaglio
M
M
Galbusera
V
V
Manzara
A
A
Claudiani
F
F
Malcangi
B
B
Varaldo
M
M
D000368:Aged; D000369:Aged, 80 and over; D000972:Antineoplastic Agents, Phytogenic / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary; D000077143:Docetaxel; D006801:Humans; D007205:Indium Radioisotopes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015282:Octreotide / Q000031:analogs & derivatives* / Q000378:metabolism; D004369:Pentetic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D049268:Positron-Emission Tomography; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D019275:Radiopharmaceuticals / Q000378:metabolism; D017481:Receptors, Somatostatin / Q000378:metabolism*; D043823:Taxoids / Q000627:therapeutic use; D014747:Vinblastine / Q000031:analogs & derivatives / Q000627:therapeutic use; D000077235:Vinorelbine
D000972:Antineoplastic Agents, Phytogenic; D007205:Indium Radioisotopes; D019275:Radiopharmaceuticals; D017481:Receptors, Somatostatin; D043823:Taxoids; C071632:SDZ 215-811; D000077143:Docetaxel; D014747:Vinblastine; D004369:Pentetic Acid; D000077235:Vinorelbine; D015282:Octreotide