Levels of Prostate Specific Antigen that Predict Skeletal Spread in Prostate Cancer

Abstract

The ability of serum prostate specific antigen (PSA) and serum acid phosphatase (SAP) to identify skeletal spread was evaluated in untreated patients with prostatic cancer. Twenty patients with scintigraphic evidence of metastatic disease in bone (M1) at diagnosis were compared with 50 untreated patients in whom scans were repeatedly negative during long-term surveillance. Using the present laboratory upper limit of normal (ULN) of 3 iu/l, the sensitivity and specificity of SAP for M1 disease were 80 and 86% respectively. Stepwise discriminant analysis demonstrated that SAP was able to stage patients correctly (bone scan positive or negative) with 81% predictive accuracy at an optimum cut-off limit of 4.6 iu/l. By contrast, whilst PSA (Hybritech) was 100% sensitive for skeletal disease at 10 ng/ml--at the expense of poor (36%) specificity--analysis determined that an optimum cut-off limit of 58 ng/ml led to 79% predictive accuracy for disease in bone. It was concluded that PSA levels > 58 ng/ml are highly indicative of spread to the skeleton, even in the absence of radiological or scintigraphic evidence of metastases.

Elevated serum vascular endothelial growth factor in patients with hormone‐escaped prostate cancer

“…From November 1997 serum samples were collected from 78 men; 48 of these had a histopathological diagnosis of prostate cancer, of whom 32 had metastatic disease. This was confirmed by bone scan in 26, MRI in one, and attributed to five patients who did not have bone scans on the basis of clinical history and markedly elevated PSA level (mean 159 ng/mL, range 118–212) [26]. Sixteen patients had local disease, confirmed by negative imaging in 14 (11 by bone scan, two by MRI and one by CT).…”

Therapeutic Dilemmas in Prostate Cancer: Justification for Watchful Waiting

“…Since then a number of studies have disclosed the range of PSA within which it is relatively safe to reassure the patient on a surveillance programme [7]. Nonetheless, PSA may be a poor surrogate marker for tumour activity and although most watchful waiting protocols will involve patients with well differentiated neoplasms, tumour grade may deteriorate with time so due vigilance will always be required.…”