Detection of Clinically Occult Prostate Cancer

Holmium laser prostatectomy

Holmium laser prostatectomy has evolved in the last decade to reproduce the short- and long-term results of both transurethral and open prostatectomy. This article discusses our surgical approach at the Methodist Hospital of Indiana as well as offers a review of the literature of holmium prostatectomy.

Correlations among prostatic biopsy results, transrectal ultrasound findings and PSA levels in diagnosing prostate adenocarcinoma

OBJECTIVE

The objective of this study was to evaluate transrectal ultrasound (TRUS) findings and prostate-specific antigen (PSA) levels in relation to prostatic biopsy results and to analyze their individual and combined performances in diagnosing prostate adenocarcinoma (PAC).

METHODS

Men (n=143) with PSA levels above 4 ng/ml underwent TRUS and randomized ultrasound-guided prostatic biopsy through the peripheral zone, including additional hypoechoic nodules biopsies, if they were noted on TRUS. Data related to TRUS, biopsy, and PSA level results were then correlated.

RESULTS

A significant correlation between TRUS images suspicious for PAC and a biopsy-confirmed diagnosis of PAC, or between the lack of such images and a negative biopsy result, was not found. However, a significant correlation was found between positive biopsy results and PSA levels greater or equal to 10 ng/ml. The sensitivity of transrectal ultrasound in making a diagnosis of PAC was 63%, whereas its specificity was 73%.

CONCLUSION

We conclude that while the separate performances of these examinations were not effective in diagnosing PAC, the integrated use of these methods was more adequate for making the diagnosis.

Histologic effects of holmium:YAG laser resection versus transurethral resection of the prostate

BACKGROUND AND PURPOSE

Holmium laser resection (HoLRP) is an effective surgical alternative to transurethral resection of the prostate (TURP). We investigated whether an adequate histologic diagnosis could be made from HoLRP tissue specimens.

PATIENTS AND METHODS

A series of 120 patients were randomized to TURP (N = 59) or HoLRP (N = 61). Each histologic specimen was reviewed by a single pathologist, who was blinded to the treatment. Weight of tissue, histologic diagnosis, and degree of thermal artifact were assessed. Thermal damage was graded as follows: 1 = no significant thermal injury; 2 = <25% of the tissue damaged (minimal); 3 = 25% to 80% of the tissue damaged (moderate); and 4 = >80% of the tissue damaged, with loss of prostatic architecture (extensive).

RESULTS

The mean weight of the TURP and HoLRP specimens was 15.6 g and 9.6 g, respectively. The mean grade of thermal artifact for the TURP group was 1.8 and for the HoLRP group 2.6. Of the HoLRP specimens, 56 (92%) were grade < or = 3. Of the entire series of 120 specimens, 5 contained malignant tissue, all of which were from the TURP group. Four of these specimens were adenocarcinoma of the prostate, whereas the other was a transitional-cell carcinoma. Of the four specimens that contained prostate cancer, two were stage pTla tumors.

CONCLUSIONS

Although identifiable prostatic architecture was maintained in the majority of histologic specimens from the HoLRP group, the tissue quality was inferior to that of TURP. There was significantly more vaporization and subsequent tissue loss with HoLRP, and the thermal damage to tissue was greater.

Immunohistochemical detection of a fatty acid synthase (OA-519) as a predictor of progression of prostate cancer

Prostate cancer is the most common newly diagnosed non-skin cancer and the second leading cause of cancer death in men. It is a unique neoplasm because of the large discrepancy between its clinical incidence and the much higher incidence of latent cancer. Predicting the prognosis of prostate cancer, especially the cancers detected incidentally or by screening, remains a clinically important problem. Immunoreactivity for Onco-antigen 519 (OA-519), a recently described fatty acid synthase (FAS), has been associated with poor prognosis in breast cancers. The authors have previously shown that its detection in prostate cancer correlated with high-grade, large volume, and advanced stage tumors. This study examines the association between OA-519 immunoreactivity in primary prostate cancer and disease progression. The authors used immunohistochemistry with an affinity-purified anti-OA-519 antibody and examined primary prostate cancers (stages A1 to D1) from 99 men with a mean follow-up of 4 years (range = 2 to 9.3). Survival analysis was used to evaluate differences in progression-free survival. OA-519 immunoreactivity was seen in 56 (57%) of the 99 primary prostate cancers examined. OA-519-positive cancers were more likely to progress than the OA-519-negative cancers (P < .04). Univariate survival analysis showed that OA-519 (FAS), histological grade (Gleason score), and clinical stage were significant predictors of disease progression. Multivariate analyses of all cases showed that only histological grade was significant. However, multivariate analysis of the 85 cancers with Gleason scores 2-7 (ie, low to intermediate grade) showed OA-519 (FAS) immunoreactivity to be the only statistically significant predictor of cancer progression (P < .02). Expression of the fatty acid synthase OA-519 by prostate cancers is potentially a clinically useful predictor of disease progression. It appears to be independent of histological grade (Gleason score), at least in cancers with low to intermediate grades. Further studies are needed to evaluate the role of fatty acid synthase in malignancy and the potential therapeutic implications of enzyme blockers.

p53 expression in incidental prostatic cancer

Incidental prostate cancer is an indolent disease typically characterized by a benign clinical course. This is not clearly established, however, as recent reports suggest that up to 27% of cases progress with long-term follow-up. The indolent history of this disease led initially to the hypothesis that mutations of the p53 gene would be an infrequent event in this patient population. Archival specimens from 24 patients with Stage A1 carcinomas were evaluated for abnormal p53 expression. In 23 patients the disease was diagnosed after transurethral resection for bladder outlet obstructive symptoms, and in one patient after a radical prostatectomy. Using a monoclonal antibody (PAb 240) and an immunohistochemical technique, a total of 36 microfoci of tumor were evaluated. Thirteen (36%) microfoci were positive with an intense nuclear staining pattern (2+), and eight (22%) microfoci had an intermediate staining pattern. Four areas of prostatic intraepithelial neoplasia also stained positively with a 2+ staining pattern. These results suggest that abnormal p53 expression is a feature of a significant number of incidental prostatic carcinomas and that this occurrence is an early event in the development of the malignant phenotype.