Value of ultrasound-guided systematic sextant biopsies in prostate tumor mapping

OBJECTIVE: To determine the value of positive sextant biopsies in assessing the location of prostate tumors within radical prostatectomy specimens and to determine if prostate weight influences the results. METHODS: From 1988 to 1996, 166 radical prostatectomies were performed for localized prostate cancer diagnosed by means of ultrasound-guided sextant biopsies. The location of the biopsies was compared with that of tumor tissue within the radical prostatectomy specimen. RESULTS: Of the 996 biopsies, 331 (33%) were positive. The correspondence between the location of the biopsies and that of tumor tissue in the surgical specimen was found to have a sensitivity of 39.4%, a specificity of 81.5%, a positive predictive value of 83.3%, negative predictive value of 36.4% and an accuracy of 52%. For prostates weighing < and >/= 45 g, the sensitivity was 39.9 and 38.9%, the specificity was 88 and 77.2%, the positive predictive value was 90.8 and 76.1%, the negative predictive value was 34.9 and 39.8%, and the accuracy was 52 and 52%, respectively. CONCLUSION: Negative biopsies do not predict a lack of tumor tissue in the corresponding prostate site after radical prostatectomy, and had less value than positive biopsies for prognostic staging before radical prostatectomy. Results of sextant biopsies are more significant for prognosis before radical prostatectomy when positive. Prostate weight influences the interpretation of the results of sextant biopsies.     

Comparison of cancers detected at only a sextant or alternative location

OBJECTIVES

To evaluate the effect of the tumour‐positive biopsy site at extended biopsy on tumour volume and potential biological significance of prostate cancer.

PATIENTS AND METHODS

We retrospectively evaluated radical prostatectomy specimens from 247 consecutive men diagnosed with prostate cancer by extended biopsy. Men who had both a positive sextant and alternative site were excluded, resulting in 132 evaluable men. We assessed age, pretreatment prostate‐specific antigen (PSA) level, prostate volume, pathological stage, Gleason score, total tumour volume, and location (sextant or alternative site) of the positive biopsy. Patients were grouped by location of the positive biopsy, i.e. sextant site only or alternative site only, including anterior horn, midline region and transition zone.

RESULTS

A biopsy from a sextant‐only or an alternative site only was positive in 42% (56/132) and 58% (76/132) of men, respectively. There was no significant difference in PSA level, number of positive cores, pathological stage, Gleason score, total tumour volume or the incidence of low‐volume/low‐grade cancer (volume <0.5 mL and a Gleason score of ≤6) between the groups. In men with one positive core, there was no significant difference in total tumour volume (median 0.20 vs 0.36 mL, respectively) or in the incidence of low‐volume/low‐grade cancer (42% vs 40%, respectively) between the groups.

CONCLUSIONS

Total tumour volume and the incidence of low‐volume/low‐grade cancer detected at an alternative site only were comparable to those of cancers detected at a sextant site only. Alternative site biopsy did not increase the incidence of low‐volume/low‐grade cancers detected.     

Screening of prostate cancer with PSA and transperineal six sextant biopsy]

OBJECT: The objectives of this study are to examine how many cancer patients we can detect among the outpatients whose PSA values are above 4.0 ng/ml, and to compare the usefulness of transperineal six sextant biopsy (ss-biopsy) with that of transrectal one. METHODS: All the male outpatients (above 50 years old) were inspected Tandem-R PSA levels and digital rectal examination (DRE). Among them, 129 patients showed more than 4.0 ng/ml of PSA values and/or positive finding of DRE, and underwent subsequent transperineal ss-biopsy. RESULTS: Cancers were detected in 52 patients (40.3%) without major complications. Among 64 gray zone (PSA 4.1-10.0 ng/ml) patients, 17 (26.6%) were found to be cancer by ss-biopsy, meanwhile only 2 cancer patients (8.9%) were detected from 23 gray zone ones by traditional directed biopsy. Application of PSA density could not be found practicable to eliminate unnecessary biopsies in the gray zone group. CONCLUSION: Prostate cancer could be found nearly a fourth in the gray zone group of the outpatients. To enhance the detection rate, obtaining at least 6 core samples are recommended from either perineal or rectal root.     

Comparison of systematic sextant and lesion directed biopsies in prostate cancer detection

This study was designed to determine the value of performing separate lesion directed biopsies in addition to systematic random sextant biopsies for the detection, grading, and assessment of bilaterality of prostate cancer. A prospective study of 82 consecutive patients who had peripheral zone hypoechoic regions visualized on transrectal ultrasound was performed. All patients had either an abnormal prostate-specific antigen or an abnormal digital rectal examination and underwent random systematic and lesion directed biopsies. Cancer detection, laterality, and histologic grade of lesion directed biopsies were compared with those from systematic random biopsies. Prostate cancer was detected in 35 (40%) of 82 patients who had a hypoechoic lesion visualized. Three (9%) cancers would have been missed if only systematic biopsies had been performed, while nine (26%) cancers would have been missed if only lesion directed biopsies had been performed. In all but one patient, the Gleason score of the lesion directed biopsy was equal to or within one grade of the highest Gleason score determined from systematic biopsy. Systematic random biopsies detected cancer on the opposite side of a positive lesion directed biopsy in 48% of patients. In no case did a lesion directed biopsy add to the detection of bilateral disease. In conclusion, lesion directed biopsies increase the detection of prostate cancer when performed in addition to systematic random sextant biopsies. However, lesion directed biopsies alone would result in a substantial miss rate of prostate cancer. They do not add to the determination of bilateral disease, nor do they add to the pathologic grading of the detected cancer.     

Telomerase activity in prostate sextant needle cores from radical prostatectomy specimens

Human telomerase acts to maintain functioning telomeres, which are required for cellular immortality and very likely for cancer progression. Telomerase activity is present in about 85% of human cancers tested, but it has not been found in most human somatic cells and tissues. We used the Telomeric Repeat Amplification Protocol to perform telomerase activity assays on sextant needle core samples obtained from 35 freshly excised radical retropubic prostatectomy specimens. Similar assays were done on prostatic tissues obtained by means of other urologic procedures from 8 patients without prostate cancer. Telomerase activity was found in one or more specimens from 32 of 35 prostate cancer patients (91%), but was not detectable in all biopsy specimens from 7 of 8 cancer-free patients (88%). Further analysis showed that cancers more poorly differentiated, with higher Gleason scores, were always associated with a higher rate of telomerase detection and stronger telomerase activity. Moreover, comparison of telomerase activity in needle core samples with the volume of cancer in surrounding tissue as observed on corresponding histologic slides showed that stronger activity was positively correlated with a higher cancer volume. Prognostic indicators of prostate cancer and the expression of telomerase appear to be linked. The presence of telomerase activity in prostate tissue may aid in the detection of prostate cancer and produce additional prognostic information.     

Comparison of Gleason scores from sextant prostate biopsies and radical prostatectomy specimens.

OBJECTIVES: We compared the Gleason scores obtained from sextant prostate biopsy and radical prostatectomy (RP) specimens in patients with localized prostate cancer. PATIENTS AND METHODS: Sixty-one patients having a clinical diagnosis of localized prostate cancer underwent needle biopsy under transrectal ultrasonography (TRUS) and RP. Grading and staging were assigned based on Gleason scores and the TNM system, respectively. RESULTS: Mean patient age was 65.5 +/- 13.43 years and mean PSA level was 14.69 +/- 3.95. Mean Gleason score for prostate biopsy and RP specimen were 5.85 +/- 0.7 and 6.34 +/- 1.44, respectively. With respect to clinical stage, there were 20 patients in stage 1 and 41 patients in stage 2 prostate cancer. Comparing the Gleason scores, the biopsy score was lower in 26 (42.26%) and higher than RP specimens in 7 (11.84%) cases, and there was agreement between the biopsy and RP specimens in 28 (45.9%) patients. The difference between the two Gleason scores was +/- 1 for 18 patients (29.5%) and +/- 2 or more for 17 patients (27.86%). CONCLUSION: In our study, high Gleason score biopsies with elevated PSA level (>10 ng/ml) were risk factors for extraprostatic extension, and we demonstrated that Gleason scores were significantly correlated with seminal vesicle and lymph node invasion (p < 0.05). The Gleason scores of biopsy and RP specimens agreed with 45.9% of TRUS-guided sextant prostate biopsies, and this ratio was 91.1% in moderately differentiated tumors Copyright 2001 S. Karger AG, Basel     

Predicting unilateral prostate cancer on routine diagnostic biopsy: sextant vs extended

Study Type – Diagnosis (exploratory cohort)
Level of Evidence 2b

OBJECTIVE

To compare the diagnostic properties of routine office‐based sextant and extended biopsies for unilateral prostate cancer, as validated by final pathology, because focal therapy of prostate cancer is gaining acceptance as a viable treatment option and thus patient selection is of paramount consideration.

PATIENTS AND METHODS

We retrospectively analysed records of patients who had a radical prostatectomy (RP) for biopsy confirmed prostate cancer at our institution between 1990 and 2007. Records with incomplete data were excluded. Diagnostic properties for sextant and extended biopsies were calculated and compared for diagnostic accuracy, sensitivity, specificity, positive and negative predictive values (PPV, NPV) and false‐positive and ‐negative rates.

RESULTS

We identified 882 records (729 sextant, 153 extended biopsies) matching our criteria. Overall, unilateral prostate cancer was confirmed in 151 (16%) of pathological RP specimens. The sensitivity improved from 84.1% to 88.0% on sextant and extended biopsy, respectively. Similarly, the PPV increased from 21.9% to 27.2%, specificity from 37.1% to 53.9% (P < 0.05), and NPV from 91.8% to 95.8% (P < 0.05). These changes are reflected in the decrease in false‐positive rates (from 62.9% to 46.1%) and false‐negative rates (from 15.9% to 12.0%). The overall diagnostic accuracy increased from 49% on sextant to 59% on extended biopsy (P < 0.05).

CONCLUSIONS

Taking more prostate biopsy cores improves the diagnostic properties for identifying unilateral prostate cancer. However, a 12‐core biopsy is not an ideal diagnostic test to select patients for focal therapy, and should be interpreted in conjunction with imaging and clinical variables. Additional research should investigate the diagnostic gain associated with a further increase in the number of biopsy cores.     

One 10-core prostate biopsy is superior to two sets of sextant prostate biopsies

OBJECTIVES: To compare the efficiency of different transrectal ultrasonography (TRUS)-guided prostate biopsy techniques for detecting prostate cancer. MATERIALS AND METHODS: In all, 81 prostates from radical prostatectomy were used and two consecutive sets of sextant biopsies and one 10-core biopsy taken in each specimen. The 10-core biopsy consisted of a sextant biopsy and four cores from the far lateral areas of the prostate. To simulate a transrectal biopsy procedure, all biopsies were taken under TRUS guidance. RESULTS: In the first set of sextant biopsies 44 prostate cancers (54%) were detected and in the second set 51 (63%). Combining both sets of sextant biopsies 57 (70%) of the carcinomas were detected. One set of 10-core biopsies detected 66 (82%) of all prostate cancers. Overall, with the 10-core biopsies 16% more prostate tumours were diagnosed than with two consecutive sets of sextant biopsies. To find the same number of prostate cancers as with the 10-core technique, 14% of patients undergoing sextant biopsy would require a second set and 11% at least a third set of biopsies. CONCLUSIONS: The 10-core prostate biopsy technique is superior to the commonly used sextant technique and could spare patients unnecessary repeated biopsy. Even after including a second set of sextant biopsies, the total detection rate with these 12 biopsies was inferior to the 10-core technique.     

A comparative analysis of sextant and an extended 11-core multisite directed biopsy strategy

PURPOSE: The 3 tumor locations unsampled by conventional sextant biopsies that have been identified on composite 3-dimensional reconstruction of 180 radical prostatectomy specimens are the anterior transition zone, midline peripheral zone and inferior portions of the anterior horn in the peripheral zone. We evaluated an 11-core multisite directed biopsy scheme incorporating these alternate areas and conventional sextant biopsies in 362 patients from 2 institutions. MATERIALS AND METHODS: Patients without a prior diagnosis of cancer underwent ultrasound guided 11-core biopsies which included conventional sextant and 3 alternate sites. All specimens were separated for specific location identification. Biopsy was performed in 183 patients at MD Anderson Cancer Center (group 1) and in 179 at Toronto General Hospital (group 2). All group 2 and 54% of group 1 patients (98 of 183) had a prior biopsy negative for cancer. RESULTS: Median prostate specific antigen was higher in group 2 than in group 1 patients (11.5 versus 9.5 ng./ml., p = 0.016). Overall a 33% increase (36 of 110 patients) in cancer detection was observed when biopsy technique included the alternate areas (p = 0.0021). The anterior horn was the most frequently positive biopsy site followed by the transition zone and midline sites. The 11-core technique had significantly better cancer detection rates when digital rectal examination and transrectal ultrasound were normal, and in men with serum prostate specific antigen between 4.1 and 10 ng./ml. CONCLUSIONS: Biopsies of the alternate sites suggested by our simulation studies are feasible and reproducible. This new strategy significantly enhanced (p = 0.0075) prostate cancer detection compared to conventional sextant biopsies in men undergoing a repeat procedure.     

Sextant prostate biopsies predict side and sextant site of extracapsular extension of prostate cancer

PURPOSE: We examined the ability of sextant prostate biopsies in combination with other preoperative data to predict side and sextant site of prostate cancer extracapsular extension in a large cohort of patients. MATERIALS AND METHODS: We examined 223 contemporary cases of prostate cancer managed by radical prostatectomy. Using logistic regression analysis, we determined whether patient age, Gleason score, clinical stage, prostate specific antigen, number of positive sextants, biopsy location or percent of biopsy cores positive for cancer in a sextant site, side and overall gland was predictive of location of pathological extracapsular extension into periprostatic tissue. RESULTS: Of 41 of the 223 (18%) patients with nonorgan confined disease extracapsular extension was localized to 45 sextant sites in 36 (apex 8, mid 22, base 15) while only side of extension was known in 5. In a multivariate analysis the best predictors of the risk of extracapsular extension on a side were average percent biopsy cores positive for cancer overall 15 or greater (odds ratio 8.4, p <0.0001) and average from 3 ipsilateral biopsies 15 or greater (odds ratio 7.4, p <0.0001). When used in combination these 2 factors yielded a model with a positive predictive value of 37% and a negative predictive value of 95%. Sextant specific percent biopsy cores positive for cancer was predictive of risk of extracapsular extension in a sextant (odds ratio 2.5, p = 0.020). CONCLUSIONS: Our data demonstrate that average overall and per side percent biopsy cores positive for cancer is a significant predictor of risk of extracapsular extension on a side. Sextant specific percent biopsy cores positive for cancer is predictive of sextant site of extension. The high negative predictive value of the side specific model identifies patients who are good candidates for nerve sparing surgery.     

Optimal combinations of systematic sextant and laterally directed biopsies for the detection of prostate cancer

PURPOSE: The standard sextant protocol for obtaining transrectal ultrasound guided biopsy of the prostate has been shown to underestimate the presence of prostate cancer. Studies have demonstrated an increased cancer detection rate with additional laterally directed biopsies. We compared the sensitivity of individual biopsy cores and evaluated combinations of these cores to identify an optimal biopsy strategy. MATERIALS AND METHODS: A total of 396 consecutive patients underwent biopsy of the lateral peripheral zone in addition to standard sextant biopsy. The cancer detection rate for each biopsy core was calculated. The sensitivity of different combinations of biopsy cores was compared with those of standard sextant biopsies and with a 12 core biopsy protocol that combined the standard sextant biopsy with a complete set of laterally directed cores. RESULTS: Cancer was detected in 160 of 396 (40.3%) patients. Of the possible combinations of biopsy cores a strategy that included laterally directed cores at the base, mid gland and apex of the prostate with mid lobar base and apical cores detected 98.5% of cancers. The detection rate of this 10 core biopsy regimen was significantly better than that of the standard sextant protocol (p < or =0.001), and was equivalent to that of the 12 core regional biopsy (p > or =0.302). CONCLUSIONS: The standard sextant protocol failed to detect a large proportion of cancers located laterally in the peripheral zone. A 10 core biopsy regimen that combined laterally directed cores at the base, mid gland and apex of the prostate with mid lobar biopsy cores at the base and apex maximizes the sensitivity of transrectal ultrasound guided systematic biopsy.     

Six additional systematic lateral cores enhance sextant biopsy prediction of pathological features at radical prostatectomy

PURPOSE: We evaluated the contribution of 6 additional systematically obtained, laterally directed biopsy cores to traditional sextant biopsy for the prediction of final pathological findings in the radical prostatectomy specimen. MATERIALS AND METHODS: We studied 178 consecutive patients with no history of prostate biopsy in whom prostate cancer was diagnosed during an initial systematic 12 core biopsy and who subsequently underwent radical prostatectomy. Of the systematic 12 cores we compared the subset of the 6 traditional sextant cores (S6C), the set of 6 laterally directed cores (L6C) and the complete 12 core set, which included the 6 traditional sextant and the 6 laterally directed cores. Biopsy Gleason score, number of positive cores, total cancer length and percent of tumor in the biopsy sets were examined for their ability to predict extracapsular extension, total tumor volume and pathological Gleason score. RESULTS: On univariable analyses the biopsy parameters of the complete 12 core set correlated more strongly with extracapsular extension and total tumor volume than the biopsy parameters of S6C or L6C. On multivariable analyses S6C and L6C were independent predictors of pathological features at prostatectomy. CONCLUSIONS: The addition of 6 systematically obtained, laterally directed cores to traditional sextant biopsy improved the ability to predict pathological features at prostatectomy by a statistically and prognostically significant margin. Preoperative nomograms that use data from a full complement of 12 systematic cores, specifying sextant and laterally directed biopsy cores, should demonstrate improved performance in predicting prostatectomy pathology.     

Extensive repeat transrectal ultrasound guided prostate biopsy in patients with previous benign sextant biopsies

PURPOSE: Standard sextant prostate biopsy may underestimate cancer in men in whom clinical findings are suspicious for localized prostate cancer. We describe our experience with extensive transrectal ultrasound guided prostate biopsy in men in whom previous sextant biopsy was negative. MATERIALS AND METHODS: Between November 1997 and March 1999, 57 men 47 to 72 years old (mean age 61.4) underwent extensive transrectal ultrasound guided biopsy of the prostate using intravenous sedation at our institution. An average of 22.5 cores (range 15 to 31) were obtained depending on prostate size. Biopsies were obtained from each of 6 sagittal regions, including samples from the far lateral and mid transitional zones. Each patient had undergone at least 1 previous benign transrectal ultrasound guided sextant biopsy (mean 2.1, range 1 to 4). Indications for repeat biopsy were persistently elevated prostate specific antigen (PSA) in 89% of the cases, increased PSA velocity in 63%, suspicious free-to-total PSA in 39% and a previous suspicious biopsy finding in 32%. Clinical factors (PSA, PSA velocity, free-to-total PSA and previous suspicious biopsy) were analyzed for the ability to predict positive biopsy, and tumor parameters were assessed pathologically in patients undergoing radical prostatectomy. RESULTS: Adenocarcinoma was identified in 17 of the 57 men (30%). Biopsy revealed a Gleason score of 6 to 8 (mean 6.4). In 7 of the 17 patients (41%) in whom cancer was identified only 1 biopsy core was positive. Of the 15 patients in whom previous sextant biopsy had demonstrated high grade prostatic intraepithelial neoplasia or atypical small acinar proliferation extensive biopsy revealed cancer in 7 (47%). Although serum PSA was higher and free-to-total PSA was lower in those with cancer, the only statistically significant predictor of positive biopsy was PSA velocity (p <0.001). Prostate cancer was noted in 64% of the men with PSA velocity 1 ng./ml. or greater. Of the 13 patients undergoing radical prostatectomy pathologically significant disease was identified in all but 1 (92%). Complications of extensive biopsy included urinary retention in 6 patients and limited rectal bleeding in 1. CONCLUSIONS: Extensive prostate biopsy identifies significant prostate cancer in many men in whom previous sextant biopsy was benign. This procedure should be considered when findings are suspicious for adenocarcinoma despite previously negative sextant biopsy.