Diagnosis and localization of prostate carcinoma by fine-needle aspiration cytology and correlation with histologic whole-organ sections after radical prostatectomy

Prostate cancer: prediction of biochemical failure after external-beam radiation therapy--Kattan nomogram and endorectal MR imaging estimation of tumor volume

PURPOSE

To determine whether magnetic resonance (MR) imaging and MR spectroscopic imaging findings can improve predictions made with the Kattan nomogram for radiation therapy.

MATERIALS AND METHODS

The institutional review board approved this retrospective HIPAA-compliant study. Ninety-nine men who underwent endorectal MR and MR spectroscopy before external-beam radiation therapy for prostate cancer (January 1998 to June 2007) were included. Linear predictors were calculated with input variables from the study sample and the Kattan original coefficients. The linear predictor is a single weighted value that combines information of all predictor variables in a model, where the weight of each value is its association with the outcome. Two radiologists independently reviewed all MR images to determine extent of disease; a third independent reader resolved discrepancies. Biochemical failure was defined as a serum prostate-specific antigen level of 2 ng/mL (2 μg/L) or more above nadir. Cox proportional hazard models were used to determine the probabilities of treatment failure (biochemical failure) in 5 years. One model included only the Kattan nomogram data; the other also incorporated imaging findings. The discrimination performance of all models was determined with receiver operating characteristics (ROC) curve analyses. These analyses were followed by an assessment of net risk reclassification.

RESULTS

The areas under the ROC curve for the Kattan nomogram and the model incorporating MR imaging findings were 61.1% (95% confidence interval: 58.1%, 64.0%) and 78.0% (95% confidence interval: 75.7%, 80.4%), respectively. Comparison of performance showed that the model with imaging findings performed significantly better than did the model with clinical variables alone (P < .001). Overall, the addition of imaging findings led to an improvement in risk classification of about 28%, ranging from approximately a minimum of 16% to a maximum of 39%, depending on the risk change considered important.

CONCLUSION

MR imaging data improve the prediction of biochemical failure with the Kattan nomogram after external-beam radiation therapy for prostate cancer. The number needed to image to improve the prediction of biochemical failure in one patient ranged from three to six.

The alpha 6 beta 1 and alpha 6 beta 4 integrins in human prostate cancer progression

Prostatic secretions are formed by glands composed of basal and luminal cells and surrounded by a basal lamina. The normal basal cells express several integrins (extracellular matrix receptors) including alpha 2, 3, 4, 5, 6, v, beta 1 and beta 4. These integrin units are polarized at the base of the cells adjacent to the basal lamina. The integrin alpha 6 beta 4 is associated with hemidesmosomal-like structures. The natural history of prostate cancer involves the presence of prostatic intraepithelial neoplasia (PIN) lesions (considered precursor lesions), carcinoma in situ and invasive carcinoma. Hemidesmosomal proteins and the alpha 3 beta 1 and alpha 6 beta 1 integrins (laminin receptors) are retained in the early PIN lesions. Expression of the integrins alpha 2, alpha 4, alpha 5, alpha v and beta 4 is lost in carcinoma. The alpha 3 beta 1 and alpha 6 beta 1 integrins remain associated with invasive carcinoma, the latter being predominant. Integrin expression in carcinoma is diffuse in the plasma membrane and not restricted to the basal aspects of the cell. The alpha 6 beta 1 integrin is fully functional as judged by an ability to adhere to laminin and contains the wild type alpha 6A cytoplasmic signaling domain. The alpha 6 beta 1 integrin is a leading candidate for conferring the invasive phenotype in prostatic carcinoma. Tumor cells with high expression of alpha 6 integrin are more invasive when tested in a SCID mouse model system. Following intraperitoneal injection, the human tumor cells invade the mouse diaphragm and move through the muscle on the surface of the laminin coated muscle cells. Our current working hypothesis is that the production of alpha 6 beta 1 and laminin in human tumor cells contributes to the invasive phenotype. Invasion could occur on the surfaces of laminin coated structures such as the nerves, blood vessels or muscle and account for the known patterns of human prostate tumor progression. Blockage of the expression or function of alpha 6 beta 1 or laminin or preventing the loss of beta 4 would be essential steps in confining the carcinoma to the prostate gland where conventional treatment has already proven effective.

Usefulness of aspiration cytology in prostate cancer detection

Aspiration cytology and core needle biopsy were performed in 79 patients who were suspected of having prostate cancer. Aspiration cytology and TURP were done in 77 cases not suspected of the disease. In the former group, they were both positive in 13 cases, aspiration cytology was negative and core needle biopsy positive in 4, and the reverse in 3 cases in whom cancer was confirmed by repeat core biopsy. All of the latter group were judged by aspiration cytology as being benign. Three cancers were detected by TURP. Aspiration cytology is a recommendable method in subjects with suspected prostate cancer.

Preoperative histological and cytological diagnosis and DNA ploidy assessment of localized prostatic cancer. A comparison between findings in biopsies and total prostatectomy specimens

The preoperative biopsy specimens of 49 men who underwent radical prostatectomy were compared with serially step-sectioned operative specimens, in order to evaluate diagnostic accuracy as regards the presence of cancer, its grade and its DNA ploidy. Both the FNAB and TRUS-GCB undergraded the cancer by one WHO grade in about 35-40% of cases. In cases where both biopsy types were available, the degree of undergrading was the same. Determination of DNA ploidy by the single-cell technique from FNAB had a sensitivity for detecting non-diploid DNA patterns of 59% whereas flow cytometric measurement of core biopsies had a sensitivity of 44.4% as regards non-diploid DNA, when compared with operative specimens. A comparison of ploidy in core biopsies versus ploidy in fine-needle aspirates revealed that more non-diploid DNA patterns were diagnosed in the fine-needle aspirates. These aneuploid patterns were not all confirmed by flow cytometric evaluation of the operative specimens, in which, however, more aneuploid patterns were diagnosed compared with the single-cell technique from FNAB. We conclude that the standard technique with 1-3 fine-needle aspirates or 1-3 TRUS-GCB has a pronounced tendency by both biopsy methods to underestimate the tumour grade. DNA ploidy analysis by FNAB and the single-cell cytometric method reveals aneuploid cell lines not found in the flow cytometric evaluation. In order to determine whether this reflects a methodological problem or a true discrimination between the ability of the two methods to find non-diploid cell lines further studies are needed. However, for a more correct preoperative assessment of tumour grade and DNA ploidy, more extensive sampling is required.

Transrectal ultrasound screening for prostatic adenocarcinoma with histopathological correlation. Factors affecting specificity

BACKGROUND

Ultrasound (US) is increasingly used for the detection of prostatic cancer, yet its specificity is low when used alone. A study was undertaken to examine the factors affecting the specificity of prostatic US.

METHODS

Thirty-five intact prostates obtained at autopsy were studied in vitro by US, and the findings were correlated with those in histologic sections.

RESULTS

US abnormalities were noted in 24 cases, but prostatic adenocarcinoma was diagnosed by US in only 5 of 12 proven cases. It appears that the US diagnosis of tumor is determined more by location than by size. Anterior and central tumors often are missed by US. Benign prostatic hyperplasia, which affects the transition zone, contributed to a false-positive or false-negative diagnosis of tumor in 10 of 35 cases. Other findings associated with abnormal US include abscesses, infarcts, and seminal vesicles embedded in the prostate.

CONCLUSION

The specificity of prostatic US is low; it should not be used as an isolated test in screening the prostate for tumors.

Radical retropubic prostatectomy for localised prostatic carcinoma: a clinical and pathological study of 201 cases

To examine the role of radical retropubic prostatectomy in clinically localised prostatic cancer we reviewed a series of 201 patients all of whom had undergone bilateral pelvic lymphadenectomy. Frozen section showed metastatic pelvic lymph nodes in 13 cases and 6 cases were too locally advanced for operation; prostatectomy was done for the remaining 182. The pathological staging was based on examination of sections of the whole organ. In 109 (60%) the carcinoma was confined to the prostate gland or to the specimen, in 46 (25%) there was carcinomatous growth in the surgical margin, and in 27 (15%) there was invasion of the seminal vesicles. The Gleason score was significantly higher in cases with involvement of the surgical margin or seminal vesicles. There was one operative death (of pulmonary embolism), and the postoperative cardiovascular morbidity was 7%. The incidence of wound infection was 6%, and there were two rectal injuries and three symptomatic lymphoceles. A total of 135/170 evaluable patients (79%) were completely continent postoperatively, and only two developed severe incontinence. Erectile potency was preserved in 24 of 126 (19%). We conclude that radical retropubic prostatectomy is safe and that the complication rate is acceptable. The completeness of the tumour excision seems to be associated with the pathological grade of the tumour.

The roles of fine needle aspiration and needle core biopsies in the diagnosis of primary prostatic cancer

For more than 50 years, needle core and aspiration biopsy techniques have been used to detect carcinoma of the prostate. Each has had vigorous proponents and many technical innovations have been made to improve the techniques. This report summarizes the developmental history of the techniques, examines their individual merits, reviews studies comparing the methods, and discusses the complications associated with each. Presently, in patients with abnormal rectal examinations, small-gauge transrectal core biopsy and transrectal aspiration biopsy offer similar detection and false-negative rates with very low frequencies of complications.