OBJECTIVES: Prostate cancer is the second most frequent neoplasia among men. Its staging is of greatest importance both to define treatment, as to prognostic evaluation. Bone scintigraphy is one of the most used methods for the investigation of bone metastasis in patients with this kind of malignity. The aim of this work is to make a correlation between PSA values and Gleason score results, at the time diagnosis is firmed, with the possible presence of bone metastasis as investigated by scintigraphic methods.
MATERIAL AND METHODS: 195 (hundred and ninety five) prostate cancer patients, having an average age of 69 yr. old (52 - 87) were retrospectively studied. They had been submitted to scintigraphic exams for staging of the disease in the period of september 2003 to june 2004. Forty two of those patients (21%) had PSA<10; thirty eight (19%) had PSA.between 10.1 - 20; seventy seven patients (39%) had it between 20.1 and 50. Thirty eight patients (19%) had their PSA over 50. Gleason score results showed that thirteen patients (7%), had a 5 score; fifty one (26%) a score of 6; seventy one (36%), a 7 score; thirty four (17%) a score of 8; and twenty (10%), had a Gleason score of 9. As to the scan results hundred fifty two (78%) had them normal; in ten of them (5%) they were indeterminate and thirty three of those patients (17%) had abnormal scans.
RESULTS: From those forty two patients with a PSA level <10, none presented an abnormal scan result, while among those thirty eight patients with a PSA level between 10.1 - 20, abnormal scans rate 13%. In all those patients having a PSA>20, 21% had an abnormal bone scan. When considering Gleason results it is observed that when the score is ≥ 5 no bone metastasis were found on scintigraphy, while in those cases with a Gleason score ≤ 7, metastasis rate can be over 30%.
CONCLUSION: It can be noticed from this study, that 36% of the studied patients had a Gleason 7 score and PSA level >20. was found in 58.98% of them. Coincidently with international literature findings, patients having well-differentiated tumors and low PSA levels (PSA <10) were found to have low positivity rate for bone metastasis. Since patients in our geographic region present with a Gleason score 7 and high PSA levels (PSA >20), bone scan continues to be an important procedure for disease staging in those patients, since the probability of bone metastasis occurring in that populational group is elevated.
