The Role of Extended Prostate Biopsy on Prostate Cancer Detection Rate : A Study Performed on the Bench

Introduction: The aim of this prospective study was to compare the advantage of performing prostate biopsy with a greater number of cores using the classic sextant procedure, with the aim of reducing false negative results. Materials and Methods: 100 prostates were acquired from consecutive radical prostatectomies performed by the same surgeon. Fourteen cores were obtained on the bench following surgery using an automatic pistol with an 18-gauge needle. Six of these cores were obtained according to the sextant technique, as described by Hodge et al.; with the addition of a further three lateral cores from each lobe and one from the bilateral transition zone. The whole gland and the fragments and the extended biopsies was undertaken and the results evaluated comparatively. The chi-square test was used for the comparative analysis of the cancer detection rate, according to the technique used. Results: When 6 cores were removed, the positive cancer rate was 75%, which was increased to 88% when 14 cores were cancer detection. Conclusion: rate of prostate cancer detection.


INTRODUCTION
Prostate cancer is the most common non-cumen will die of the disease (1).
A great challenge for the early diagnosis of prostate cancer is that in its initial phase, the tumor is asymptomatic and only detected by the alterations in the digital rectal examination, abnormal increase

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(PSA) or by means of transrectal ultrasound revealing hyperechoic and hypervascularized areas.When any of these alterations is found, it becomes necessary to perform a transrectal ultrasound-guided prostate biopsy.
the undertaking of routine sextant biopsy and demonstrated the superiority of the method compared to the digitally guided biopsy directed to nodules or suspected areas.This method has become the gold A study with a mathematical laboratory model showed that sextant biopsy could detect the men (4-7).Furthermore, the general sensitivity of the sextant biopsy was only 60% in patients with normal prostatic DRE (8).
the technique have been proposed, some of which suggested the acquisition of cores in a more lateral the literature as to the superiority of the techniques that involve the withdrawal of a larger number of cores for the diagnosis of adenocarcinoma of the reviewing the subject, we found only one prospective difference between the two procedures in the detection of prostate cancer.the diagnostic centers, demonstrating a general uncertainty as to the ideal number of cores to be obtained advantages from the removal of more than 6 cores, the comparison of sextant with extended biopsy was performed in groups of patients suspected of having of prostate cancer.To examine the true incidence of false negative results, it would be necessary to obtain the biopsy on patients known to be bearers of the disease (i.e., those with a previous positive biopsy).Further, the withdrawal of a large number of cores could lead to an increase in the diagnosis of tumors of no clinical importance and requiring no treatment.This question could only be answered if the entire prostate were examined histologically and completely, characteristics of the tumor.
This study compares the rates of prostate cancer detection by means of the withdrawal of 6 or 14 cores in order to determine the cancer detection rates of the two techniques.

MATERIALS AND METHODS
The study comprised of a prospective and controlled analysis of prostate glands obtained by radical prostatectomy of one hundred consecutive patients with clinically localized prostate cancer during of the hospital.
All the operations were performed by the same surgeon (MS), in accordance with the surgical technique previously described.
The inclusion criteria were the presence of adenocarcinoma of the prostate in clinical stages T1-Patients with a previous history of radiotherapy, hormone therapy or transurethral removal of the prostate were excluded.
All the surgical specimens were subjected to biopsy on the bench, immediately after their removal with an 18-gauge needle and an automatic pistol.Six cores were obtained from the peripheral zone, one from each sextant, according to Hodge et al. and were from the peripheral zone of the most lateral edge of the prostate and one core from the transitional zone and were labeled as extended biopsy.All the cores the surgical specimens, for pathological analysis.The histological reading of all the slides was carried out The biopsy cores and the surgical specimens hours.All the glands were submitted to histological study in accordance with the recommendations previously described (18).
Both the biopsy cores and the surgical specimens were investigated for the presence of adenocar-The chi-square test was used for the comparison of the frequency of the positive results in both the sextant and the extended biopsies, employing a  rejection of the null hypothesis.

RESULTS
The determined positive cancer rate was compared between the groups of the sextant and extended biopsies.Each of the specimens assessed was considered to be positive when at least one positive core was found in the sample.Table-1 shows the joint distribution of the 100 assessed specimens when six and 14 cores were analyzed.6 cores were removed the positive cancer rate was of 75%, compared to a rate of 88% when 14 cores were removed.Results of McNemar`s chi-squared test showed that there was a difference in the positive detection rate between these two techniques (p < 0.001).Thus, when 14 cores were removed there -

COMMENTS
Transrectal ultrasound-guided biopsy is the procedure of choice for the diagnosis of prostate cancer when the disease is suspected due to alterations in the PSA levels and/or alterations perceived has recently been a tendency to obtain more than 8 cores, despite a lack of standardized literature on the subject.Regardless of recent studies demonstrating that extended biopsy fails less often in the diagnosis of prostate adenocarcinoma compared to the classic sextant biopsy proposed by Hodge et al., a large number of clinics still prefer the sextant technique.Although no data on this subject has been reported, we observed that the majority of clinics continue to our study, we were able to demonstrate that 6 cores  more.
biopsy was negative, were further analyzed, it was Although no tumors were found in any of the cores, specimens showed non-localized disease.
The fact that the present study was undertaken on 100 prostates acquired from consecutive radical prostatectomies not only eliminates any possible bias in the selection of cases, but also allowed us to compare the results of the two different methods applied to the same specimens.This differentiates this study from previous reports, all of which compared biopsy, undertaken "in vivo", and therefore, on different patients.Another advantage in using surgical specimens on the bench is that the procedure permits the acquisition of cores of better quality from more precise locations, as well as being undertaken by the same investigator, which is in contrast to the published studies in which the biopsy may be taken by different doctors, introducing a possible bias.Another strength of this study is that all the operations were carried out by the same surgeon, as well as all the pathological evaluation was performed by the same uropathologist, thus avoiding the inter-observer differences that are well-known in the literature.
Because it is intuitive, it is easy to accept that an increase in the number of cores obtained in a prostate biopsy will result in an improvement in the detection rate for prostate cancer.However, there is only indirect evidence and that expectation has not example, the same author suggests opposite results.study these authors showed that there was no statisti-compared ( 14).Studies undertaken on Japanese men showed a much smaller improvement of 7.7% to sies by transperineal approach were compared, no nodule or lesion suspected by transrectal ultrasound existed, except in situations in which there was an increase in the level of PSA with no alteration in may affect the results of the biopsy is the volume of the increase in the number of cores as a function of ule but increased PSA levels, the cancer detection rate doubled when using biopsies of 10 to 14 cores relation involving the need to increase the number of biopsy cores in accordance with the volume of the prostate has also been found in a Turkish study, in which the authors suggest that the sextant biopsy was not reliable even in small prostates.The study cc should have 10 cores removed, and that in smaller same author had previously demonstrated, though without relating the number of cores to prostate volume, that when 10 cores were obtained the cancer used compared with a 6-core biopsy.who underwent radical prostatectomy, it was oburologists in the attempt to validate a nomogram to age and prostate volume of the patient, submitted nomogram.The results were then compared with those of a control group of 1,051 patients who had previously had octant biopsy and re-biopsy when the former was negative.The disease was found in used on patients of more than 70 years of age, who excluding that group of patients, the techniques that used at least 8 core samples was preferred, with the number of samples increasing in accordance with the increased weight of the gland and as the age of the patient diminished.
More recently, the possibility of using the so-called saturation biopsies, which involve the withdrawal of more than 18 cores, has been analyzed.selected men and the procedure was performed by two surgeons.The results were compared with a group of 87 patients who had previously undergone was found in the detection of the disease between these two groups.The authors concluded that a 10the literature, by which the present authors arrived at the conclusion that an investigation into prostate reported in the literature, the authors suggest that the continued use of the sextant biopsy.Even with to compare the extended with the saturation biopsy on the bench, which involves the acquisition of more than 18 cores, in an attempt to discover whether there is any advantage in this latter method in the detection of adenocarcinoma of the prostate.

EDITORIAL COMMENT
sextant transrectal biopsy may underestimate the true tumor burden within the prostate after a whole mount specimen is available.Today as technology continues to evolve, it is imperative that clinicians have the most accurate and comprehensive information available upon which to base their recommendations.We know from large retrospective series of radical prostatectomies that traditional sextant biopsy may underestimate the true tumor extent by as much as 46.6% when the whole mount specimen is examined (1).The authors are to be commended on this prospective analysis of 100 consecutive radical prostatectomy specimens performed by the same surgeon and pathology reviewed by the same pathologist.Previous investigators have demonstrated an increased yield of malignant diagnoses in vivo using extended systematic sextant biopsy To my knowledge this study is unique, based on the fact that the needle core biopsies were obtained from the RP specimen on the bench.obtained from each lobe and bilateral transition zone.These results further support the current trend of There is a subset of patients that will have negative biopsies even with the additional lateral and transitional cores, yet the PSA level may continue to rise.This particular scenario presents a diagnostic dilemma to the clinician and anxiety for the patient.transperineal prostate biopsy (STPB).Similar to a prostate brachytherapy procedure, the prostate is positioned on the implant grid.Specimens are obtained according to x, y, and z coordinates from eight equal ence in detection rates with the apex having a higher incidence of malignancy than the base of the prostate gland (p = 0.000).Furthermore, the anterior apex As our knowledge of biopsy techniques become more sophisticated, it will be possible to map malignant versus benign regions of the prostate; whether or not targeted focal therapy results from this remains to be determined.

Figure 3 -
Figure 3 -Percentage of positive detection following assessment of either 6 or 14 cores isolated from 100 prostate specimens.
the sextant biopsy: a prospective randomized controlled clinical study on cancer detection rates and protocol according to the prostate gland volume for 40.tal ultrasonography guided prostate biopsy protocol of cores based on patient age and total prostate volume.improvecancer detection as an initial prostate biopsy methods in the investigation of prostate cancer: a sys-: srougi@terra.com.br

Table 1 -
Distribution of the 100 surgical specimens assessed by biopsy.