Zonal biopsy in the detection of prostate cancer in Japanese men

Prostate Biopsy Using Transrectal Ultrasonography; The Optimal Number of Cores Regarding Cancer Detection Rate and Complications

BACKGROUND

Transrectal ultrasound guided biopsy of the prostate is the most common modality used to diagnose prostate cancer.

OBJECTIVES

The aim of this study was to evaluate the optimal number of cores at prostate biopsy, which have the most diagnostic value with least adverse effects.

PATIENTS AND MATERIALS

Transrectal ultrasonography (TRUS) guided biopsy was performed in 180 patients suspicious for prostate cancer due to either abnormal rectal examination or elevated PSA. The patients were divided randomly into three groups of six-core, twelve-core and eighteen-core biopsies. The detection rate of prostate cancer in each group with the rate of post biopsy urinary infection and prostatitis were compared.

RESULTS

Prostate cancer was diagnosed in 8 (13.3%), 21 (35%) and 24 (40%) patients in six, twelve and eighteen core biopsy groups, respectively. Urinary tract infection and prostatitis occurred in 17 (28.3%), 23 (38.3%) and 35 (58.3%) patients in six, twelve and eighteen core biopsy groups, respectively. Considering the detection rate of prostate cancer, there was a significant difference between 6 and 12 core biopsy groups (P = 0.006) and 12-core biopsies detected more cases of prostate cancer, but there was no significant difference between 12 and 18 core biopsy groups (P = 0.572). Considering the infection rate, there was no significant difference between 6 and 12 core biopsy groups (P = 0.254), but there was a significant difference between 12 and 18 core biopsy groups (P = 0.028) and infectious complications occurred more frequently in 18-core biopsy group.

CONCLUSIONS

The best balance between detection rate of prostate cancer and infectious complications of biopsies achieved in twelve-core biopsy protocol. Twelve-core biopsy enhances the rate of prostate cancer detection with minimum adverse effects.

Is transition zone biopsy valuable in benign prostatic hyperplasia patients with serum prostate-specific antigen >10 ng/ml and prior negative peripheral zone biopsy?

OBJECTIVES

To evaluate the importance of transition zone (TZ) biopsy in benign prostatic hyperplasia (BPH) patients with serum prostate-specific antigen (PSA) >10 ng/ml and prior negative peripheral zone (PZ) biopsy and to estimate the sensitivity of TZ biopsy.

MATERIAL AND METHODS

A total of 273 BPH patients with PSA >10 ng/ml and prior negative PZ biopsy underwent an extended biopsy protocol. In patients with a TZ volume <25 cm(3), four TZ biopsies were taken (two cores per side from the apex and base). In patients with a TZ volume > or =25 cm(3) (n=183), six TZ biopsies were taken (three cores per side from the apex, middle and base). Overall, 215 patients were subjected to either transurethral resection of the prostate (n=162) or open enucleation of the adenoma (n=53).

RESULTS

The extended biopsy revealed prostate cancers in 21.2% of cases (58/273). The zonal distribution of the positive cores was as follow: PZ cancers only in 67.2% of cases (39/58), TZ cancers only in 13.8% (8/58) and PZ+TZ cancers in 19% (11/58). Overall, 73.6% (14/19) and 36.8% (7/19) of TZ cancers were detected at the apex and middle of the TZ, respectively, while no TZ cancers at all were detected at the base (p=0.00015). The incidence of carcinoma on definitive pathology was 5.6% (12/215). Consequently, TZ biopsy detected only 61.3% (19/31) of TZ cancers. The incidence of pure TZ cancers was 7.3%. On the chi(2) test, patient age, serum PSA, transrectal ultrasonography findings and PSA density did not correlate significantly with the detection rate of TZ cancer. Prostate volume (p=0.023), TZ volume (p=0.027) and PSA/TZ density (p=0.007) were predictive of TZ cancers.

CONCLUSIONS

Although TZ biopsy was the sole site of cancer in only 2.9% of cases (8/273), it improved the cancer detection rate by 14% in this selected group of patients. The majority (74%) of TZ cancers were detected at the apex site. TZ biopsy has a low sensitivity (61%).

Effects of sextant transrectal prostate biopsy plus additional far lateral cores in improving cancer detection rates in men with large prostate glands

PURPOSE

To determine whether additional, far lateral cores improve the diagnostic performance of transrectal sextant biopsy in men with large prostate glands.

METHODS

Men with prostate volumes of 50 mL or greater in transrectal ultrasonography who were suspected of prostatic adenocarcinoma were prospectively enrolled. Biopsy criteria were defined as 2.0 ng/mL or greater of serum total prostate-specific antigen and/or abnormal findings on digital rectal examination. Four cores of far lateral biopsies were added to the standard sextant technique.

RESULTS

Of 104 patients enrolled in the present study and undergoing biopsy, 14 (13.5%) were diagnosed as having prostate cancer and 27 (26.0%) were diagnosed as having prostatic intraepithelial neoplasia (PIN) or an atypical gland. There were no cases where cancer was only detected in the additional cores, whereas PIN/atypical gland was uniquely detected from the additional, far lateral sites in eight of the 27 patients who were diagnosed with this condition.

CONCLUSIONS

Although the number of patients diagnosed as having PIN/atypical gland might increase with the addition of far lateral cores, this additional sampling does not improve cancer detection rates in men with large prostate glands.

Anterior distribution of Stage T1c nonpalpable tumors in radical prostatectomy specimens

OBJECTIVES

To determine the anatomic patterns of tumor distribution in radical prostatectomy specimens from nonpalpable prostate cancer.

METHODS

Tumor maps directly traced from histologic slides of 62 radical prostatectomy specimens were superimposed by a computer-assisted imaging technique to create an idealized prostate gland at three levels: apex, mid-prostate, and base. To investigate specific patterns of tumor distribution, the sites of tumor in each quadrant were compared according to risk group stratification. The tumor extent was compared with the patterns of positivity in routine sextant biopsies.

RESULTS

Among all patients, the tumor frequency was 85.5% in the mid-gland, 82.3% in the apex, and 48.4% in the base. Analysis by quadrant showed that tumors were significantly denser in the apex to mid-prostate. The primary extent of these tumors appeared to lie predominantly in the anterior half of the gland. Biopsy yields at the apex and mid-prostate appeared low compared with the frequency of cancers at these levels. No patterns specific to the different risk groups were found, but no tumors within the anterior base were found in the low-risk group.

CONCLUSIONS

The primary extent of nonpalpable tumors appeared to lie predominantly in the anterior half of the gland at the apex to mid-prostate levels. Additional biopsy cores taken from more anterior regions of the gland may enhance the detection of nonpalpable cancers further.

Prospective evaluation of prostate cancer detection by prostate-specific antigen-related parameters

BACKGROUND

The diagnostic value of prostate-specific antigen (PSA) for differentiating prostate cancer from benign prostatic conditions is limited by its lack of specificity. Several PSA-related parameters have been suggested as enhancing the discriminatory power of total PSA values, but their clinical utility should be considered preliminary until established in a prospectively evaluated cohort.

METHODS

In a prospective cohort study, results of ultrasound-guided biopsy and/or transurethral resection of the prostate gland were assessed in 706 consecutive Japanese men. The clinical usefulness of total PSA, free PSA, percentage of free PSA, PSA density (PSAD), PSA density for transition zone (PSADT) and gland volume for predicting prostate cancer was investigated using receiver operating characteristic (ROC) curve analysis in 16 different patient subgroups.

RESULTS

Overall, 150 of the 706 patients (21.2%) had prostate carcinoma. The ROC curve analysis showed that PSAD and PSADT were more powerful predictors of prostate cancer than total PSA in most of the 16 patient subgroups tested. The improvement in performance was modest, however. No substantial difference was noted between PSAD and PSADT. Total gland volume did not significantly affect the performance of these parameters. The use of a PSAD threshold value of 0.11-10.15 ng/mL per cm3 (or a PSADT value of 0.23-0.27 ng/mL per cm3) would have avoided 24-48% (or, for PSADT, 34-40%) of unnecessary biopsies at the cost of missing 5-10% of detectable cancers in a patient subgroup with intermediate total PSA levels. The performance of free PSA and percentage of free PSA was worse than that of any other test in this study. This may be due to inappropriate handling of sera prior to measurement.

CONCLUSIONS

The discriminatory potential of total PSA for predicting prostate cancer was modestly improved by the use of PSAD and PSADT. No substantial advantage of PSADT over PSAD could be demonstrated. Stringent and standardized storage conditions should always be maintained when applying free PSA-related parameters.

Results of transrectal ultrasound-guided biopsies and clinical significance of Japanese prostate cancer

BACKGROUND

We review the outcomes of ultrasound-guided biopsy in consecutive patients and assess clinical significance of Japanese prostate cancer.

METHODS

Examination was made of 1469 patients subsequent to transrectal ultrasound-guided biopsy of the prostate gland. For 84 patients, two or more sets of ultrasound-guided biopsies were conducted following the initial negative results during this period. Two hundred and thirty-two patients with benign histology at the initial biopsy underwent transurethral resection of the prostate (TURP). The clinical significance of the cancers was assessed based on patient age and calculated tumor volume at diagnosis, assumed cancer volume doubling time and life-expectancy in the Japanese male population.

RESULTS

Overall, 327 of the 1469 patients (22.3%) had prostate carcinoma. Positive biopsy rates in patients with PSA 2.0 ng/ml or lower, 2.1-4.0 ng/ml, 4.1-10.0 ng/ml and 10.1 ng/ml or greater were 4.6%, 8.6%, 15.8% and 59.5%, respectively. Of the 232 patients who underwent TURP, 15 (6.5%) had cancer. Of the 84 patients subjected to the multiple sets of biopsies, 19 (22.6%) cancers were detected. Of the 203 cancers without distant metastasis at initial biopsy, 13.3%, 25.1%, 32.5% and 40.4% of tumors for 2-, 3-, 4- and 6-year tumor doubling times gave no indication of clinical significance. Nearly half these patients (43-52%) had clinical stage T1c disease. The estimated proportion of clinically insignificant tumors in repeat biopsy was virtually the same as first set biopsies.

CONCLUSIONS

Low PSA was not necessarily an indication of indolent cancer and repeat biopsy did not often demonstrate clinically unimportant cancers. Many patients with stage T1c disease may eventually prove to require no treatment.