Re-evaluation of the need for pelvic lymphadenectomy in low grade prostate cancer

Gleason score 7 adenocarcinoma of the prostate with lymph node metastases: analysis of 184 radical prostatectomy specimens

CONTEXT

Prostate cancer (PC) with lymph node metastases (LN(+)) is relatively rare, whereas it is relatively common in disease with a Gleason score (GS) 8 to 10 and virtually never seen in PC with GS 6 or less. It is most variable in GS 7 PC.

OBJECTIVE

To determine clinicopathologic features associated with GS 7 PC with LN(+) compared with a control group without lymph node metastases (LN(-)).

DESIGN

We analyzed 184 GS 7 radical prostatectomies with LN(+) and the same number of LN(-) Gleason-matched controls. The LN(+) cases were GS 3 + 4 = 7 (n = 64; 34.8%), GS 4 + 3 = 7 (n = 66; 35.9%), GS 3 + 4 = 7 with tertiary 5 (n = 10; 5.4%), and GS 4 + 3 = 7 with tertiary 5 (n = 44; 23.9%).

RESULTS

The LN(+) cases demonstrated higher average values in preoperative prostate-specific antigen (12.2 versus 8.1 ng/mL), percentage of positive biopsy cores (59.1% versus 42.9%), prostate weight (54.4 versus 49.4 g), number of LNs submitted (12.7 versus 9.4), incidence of nonfocal extraprostatic extension (82.6% versus 63.6%), tumor volume (28.9% versus 14.8%), frequency of lymphovascular invasion (78.3% versus 38.6%), intraductal spread of carcinoma (42.4% versus 20.7%), incidence of satellite tumor foci (16.4% versus 4.3%), incidence of pT3b disease (49.5% versus 14.7%), and lymphovascular invasion in the seminal vesicles (52% versus 30%). There were differences in GS 4 patterns and cytology between LN(+) and LN(-) cases, with the former having higher volumes of cribriform and poorly formed patterns, larger nuclei and nucleoli, and more-frequent macronucleoli. All P ≤ .05.

CONCLUSION

Gleason score 7 PC with LN(+) has features highlighting a more-aggressive phenotype. These features can be assessed as prognostic markers in GS 7 disease on biopsy (eg, GS 4 pattern, intraductal spread, cytology) or at radical prostatectomies (all variables), even in men without LN dissection or LN(-) disease.

Value of prostate-specific antigen in the staging of Taiwanese patients with newly diagnosed prostate cancer

Records of 71 patients diagnosed with prostate cancer were reviewed retrospectively regarding clinical stage, prostate-specific antigen (PSA), Gleason score, CT scan of pelvis, bone scan, and pelvic lymph node dissection. Fourteen patients had pelvic lymphadenopathy based on the CT scan. Of these, no patient had a PSA level <4 ng/mL, 1 patient had a PSA level between 4 and 10 ng/mL, and 3 had a PSA level between 10 and 20 ng/mL. Twelve of 13 patients with positive bone scan results had a PSA level >20 ng/mL, and 1 patient had a PSA level between 10 and 20 ng/mL. PSA can be cost-effective in selecting and identifying appropriate staging for patients with newly diagnosed prostate cancer. CT scans are not indicated in men with clinical localized prostate cancer when PSA levels are < or =10 ng/mL. Bone scan is not required for staging asymptomatic men with PSA levels of < or =20 ng/mL. Pelvic lymphadenectomy for localized prostate cancer may not be necessary if PSA levels is < or =20 ng/mL and Gleason score is < or =5.

Reliability of preoperative values to determine the need for lymphadenectomy in patients with prostate cancer and meticulous lymph node dissection

INTRODUCTION

The only definite way to determine lymph node metastasis, an unfavorable prognostic factor in prostate cancer is lymphadenectomy. Due to increased morbidity and the increasing trend towards minimally invasive surgery, ways to avoid or at least limit lymphadenectomy are being sought. We routinely performed a meticulous lymphadenectomy in all patients and the goal of this study was to evaluate which of the previously proposed criteria determining who needs a lymphadenectomy can be applied in our patients.

PATIENTS AND METHODS

Patients with clinically localized prostate cancer confirmed by fine needle aspiration cytology, without neoadjuvant hormone therapy, negative pelvic and abdominal CT scans and negative bone scan underwent a radical prostatectomy with simultaneous bilateral extended lymphadenectomy.

RESULTS

Between 1989 and 1999, 463 patients were included in this study. The median age was 64 (range 44-76) years and the median PSA was 11.0 (range 0.42-172) ng/ml. A median of 21 nodes were removed per patient. One hundred and nine (24%) had lymph node metastasis: 17% of patients with a PSA value < or =20 ng/ml and 12% with a PSA value < or = 10 ng/ml. None of the patients with a preoperative grading of 1 and a PSA value < or =10 ng/ml and 10% of the "low-risk patients" with a PSA value < or = 10 ng/ml and a preoperative grading <3 had lymph node metastases. Seven percent with a PSA value < or = 10 ng/ml and a prostatectomy Gleason score under 7 were found to be node positive.

CONCLUSIONS

A significant number of patients would have been understaged and left with diseased nodes when applying preoperative PSA value < or = 10 ng/ml and grading <3/Gleason <7 as criteria for omitting lymphadenectomy. Therefore we consider meticulous lymphadenectomy a must for correct staging in all patients undergoing radical prostatectomy for prostate cancer, with the exception of patients with a grading of 1 and a PSA < or = 10 ng/ml.

Clinical staging of prostate cancer: reproducibility and clarification of issues

The American Joint Committee on Cancer (AJCC) staging system for prostate cancer adopted in 1992 is based on tumor-node-metastasis (TNM) designations. It has been widely accepted for use in local and advanced disease. The purpose of this study was to assess reproducibility of staging among observers and to help clarify staging issues. Twelve prostate cancer cases were sent to 20 physicians with special expertise in prostate cancer including eight urologists, eight radiation oncologists, and four medical oncologists. Physicians were asked to assign a stage based on the 1992 AJCC clinical staging. The most frequently reported stage assigned to each case was taken to be the consensus. Agreement was the percentage of physicians who reported that particular stage. Seventy-five percent of the physicians responded. The overall agreement for assignment of T stage was 63.9%. Differences were found by specialty for inclusion of available information in designating a T stage. The overall agreement for N stage was 73.8%. The most common designation was Nx regardless of availability of a computed tomography scan. The overall agreement for M stage was 76.6%. Without a bone scan the most common designation was Mx regardless of Gleason grade or prostate-specific antigen (PSA). A frequent comment was that PSA was more indicative of disease extent than current clinical staging. The reproducibility of the 1992 clinical AJCC staging is poor even among experts in the field. This problem arises primarily from disagreement regarding which studies are included in assigning a stage. Some of these difficulties are addressed in the 1997 revision. However, the clinical staging does not address the true biological significance of disease in many instances.

Impact of different variables on the outcome of patients with clinically confined prostate carcinoma: prediction of pathologic stage and biochemical failure using an artificial neural network

BACKGROUND

The advent of advanced computing techniques has provided the opportunity to analyze clinical data using artificial intelligence techniques. This study was designed to determine whether a neural network could be developed using preoperative prognostic indicators to predict the pathologic stage and time of biochemical failure for patients who undergo radical prostatectomy.

METHODS

The preoperative information included TNM stage, prostate size, prostate specific antigen (PSA) level, biopsy results (Gleason score and percentage of positive biopsy), as well as patient age. All 309 patients underwent radical prostatectomy at the University of Colorado Health Sciences Center. The data from all patients were used to train a multilayer perceptron artificial neural network. The failure rate was defined as a rise in the PSA level > 0.2 ng/mL. The biochemical failure rate in the data base used was 14.2%. Univariate and multivariate analyses were performed to validate the results.

RESULTS

The neural network statistics for the validation set showed a sensitivity and specificity of 79% and 81%, respectively, for the prediction of pathologic stage with an overall accuracy of 80% compared with an overall accuracy of 67% using the multivariate regression analysis. The sensitivity and specificity for the prediction of failure were 67% and 85%, respectively, demonstrating a high confidence in predicting failure. The overall accuracy rates for the artificial neural network and the multivariate analysis were similar.

CONCLUSIONS

Neural networks can offer a convenient vehicle for clinicians to assess the preoperative risk of disease progression for patients who are about to undergo radical prostatectomy. Continued investigation of this approach with larger data sets seems warranted.

Evaluation of a decision-support system for preoperative staging of prostate cancer

The usefulness and effectiveness of a decision-support system for preoperative staging of prostate cancers (PCES) were evaluated. The study population consisted of 43 consecutive patients with the preoperative diagnosis of prostate cancer who underwent surgical operation. Results obtained using the PCES were compared with staging by four urology attending physicians and five urology residents. The effect of PCES consultation on the physicians' staging of prostate cancer was also evaluated. To confirm the usefulness of the clinical findings of prostate-specific antigen, prostate-specific antigen density, prostate volume, and abnormal Gleason score in the PCES, their receiver operating characteristic (ROC) curves for diagnosis of advanced prostate cancer were plotted. The values of the areas under the curves were 0.772, 0.800, 0.531, and 0.752. The stage of prostate cancer was correctly determined by the PCES for 38 of the 43 patients, yielding 88.4% preoperative diagnostic accuracy. The PCES was significantly more accurate than two of the attending physicians and all residents. PCES consultation improved the residents' staging accuracy to approximately that of the attending physicians. The effect of PCES consultation on the residents' staging was significantly (p < 0.001) greater than the effect on the physicians' staging. The PCES may be useful in the preoperative staging of prostate cancers, especially during residency. The system's accuracy in determining the stage of advanced prostate cancer may make it possible to avoid unneccesary surgical operations.

Population-based study of pelvic lymph node positivity in clinically localized prostate cancer: a study comparing African Americans and whites

OBJECTIVES

To evaluate the correlation between race and lymph node metastasis for prostate cancer by analyzing which preoperative parameters may predict lymph node status in both races.

METHODS

We analyzed a group of patients (552 American white men [AWM] and 423 African-American men [AAM]) who underwent radical prostatectomy plus modified pelvic lymphadenectomy between January 1991 and June 1997. Patients who received neoadjuvant radiation or hormone therapy were excluded. Univariate and multivariate analyses were performed to determine the influence of race on lymph node positivity, as well as to correlate the preoperative parameters (serum prostate-specific antigen [PSA], biopsy Gleason score, and clinical stage) with lymph node metastasis for each race separately.

RESULTS

The AAM presented with significantly higher preoperative Gleason scores and PSA levels than AWM. However, comparing lymph node status by race, the difference of positivity (41 AWM [7.4% and 22 AAM [5.2%]) was not statistically significant (P = 0.16). The percentage of positive nodes was similar in both races for each subset of PSA, Gleason score, and clinical stage. Despite the statistical significance of the three preoperative parameters in univariate analysis, in multivariate analysis only PSA and Gleason score were independent predictors of positive lymph nodes.

CONCLUSIONS

There is no influence of race on lymph node metastasis, despite AAM presenting with higher preoperative Gleason scores and PSA levels. In multivariate analysis, preoperative Gleason score and PSA were independent factors for positive nodes regardless of race.

Evaluation of staging lymphadenectomy in prostate cancer

OBJECTIVES

To prospectively evaluate a clinical algorithm that predicts nodal status in patients with prostate cancer and to assess the impact on the outcome.

METHODS

Between September 1988 and December 1994, 192 patients with organ-confined prostate cancer and considered surgical candidates for radical perineal prostatectomy (RPP) were stratified using the algorithm: prostate-specific antigen (PSA) 20 ng/mL or less, Gleason score 7 or lower, and clinical Stage T2a or lower. Patients failing any of these criteria were placed in the high-risk group and underwent a pelvic lymphadenectomy. Patients who satisfied all the criteria were placed in the low-risk group and underwent RPP without evaluation of the pelvic lymph nodes. Another contemporaneous cohort of patients (n = 65) underwent pelvic lymphadenectomy and radical retropubic prostatectomy (RRP) without use of the algorithm and were used as a control group. Patients were monitored for at least 24 months.

RESULTS

In the RPP group, 177 patients were considered low risk according to the algorithm and were not offered staging lymphadenectomy before surgery, whereas 15 patients were categorized as high risk for metastasis and underwent staging lymphadenectomy. In the RRP and lymphadenectomy group, 41 patients were considered at low risk and 24 at high risk of disease spread according to the algorithm. In the RPP group, low-risk patients (no lymphadenectomy) had a PSA recurrence rate (27%) similar to that of low-risk patients in the RRP group with negative lymph nodes (29%), P = 0.8. Similarly, high-risk patients with negative lymph nodes in both groups had a similar recurrence rate (53% for RPP and 50% for RRP). Univariate logistic regression analysis showed that PSA was the most significant predictor for disease recurrence (P = 0.0004) followed by preoperative Gleason scores (P = 0.02) and clinical stages (P = 0.03). Multivariate stepwise analysis demonstrated that Gleason score and clinical stage did not add to the prediction of recurrence over PSA alone.

CONCLUSIONS

Staging lymphadenectomy can be omitted in low-risk patients without deleterious effects on the outcome as measured by PSA recurrence.

Systematic sextant biopsies improve preoperative prediction of pelvic lymph node metastases in patients with clinically localized prostatic carcinoma

PURPOSE

An algorithm including the results of systematic sextant biopsies was statistically developed and evaluated to predict the probability of pelvic lymph node metastases in patients with clinically localized carcinoma of the prostate.

MATERIALS AND METHODS

Clinical stage, serum prostate specific antigen concentration, Gleason score, number of positive biopsies, number of biopsies containing any Gleason grade 4 or 5 cancer and number of biopsies predominated by Gleason grade 4 or 5 cancer were recorded in 345 patients undergoing pelvic lymph node dissection and correlated with the incidence of lymph node metastases. Multivariate logistic regression, and classification and regression trees analyses were performed.

RESULTS

In univariate analysis all variables had a statistically significant influence on lymph node status. Logistic regression showed that the amount and distribution of undifferentiated Gleason grade 4 and 5 cancer in the biopsies were the best predictors of lymphatic spread followed by serum prostate specific antigen. Classification and regression trees analysis classified 79.9% of patients who had 3 or fewer biopsies with Gleason grade 4 or 5 cancer and no biopsies predominated by undifferentiated cancer as a low risk group. In this group positive lymph nodes occurred in only 2.2% (95% confidence interval 0.8 to 4.7%).

CONCLUSIONS

Including the results of systematic sextant biopsies substantially enhances the predictive accuracy of algorithms that define the probability of lymph node metastases in prostatic cancer. Patients thus defined as having no lymphatic spread could potentially be spared pelvic lymph node dissection before definitive local treatment.

The Rational Choice in the Diagnosis and Therapy of Prostatic Cancer

The authors analyse which is the best approach in diagnosing and staging prostatic cancer. They tackle the problem of screening by analysing current methods, concluding that PSA measurement is the best. It is impossible not to consider a combination of prognostic factors (Gleason score, PSA, clinical staging) when choosing pre-operative staging methods.

Use of prostate-specific antigen, Gleason score, and digital rectal examination in staging patients with newly diagnosed prostate cancer

CT Scan, MR Imaging Scan, and Pedal Lymphangiography. Patients with a PSA greater than 25 ng/mL, a Gleason score greater than 6, and a positive DRE should undergo CT scan with FNA of lymph nodes at least 6 mm in size. Otherwise, CT scan, MR imaging scan, and pelvic lymphangiogram are not indicated. This should eliminate use of these staging studies in over 90% of patients with newly diagnosed adenocarcinoma of the prostate. Pelvic Lymph-Node Dissection. Pelvic lymph-node dissection can be safely eliminated in patients who meet the following predictive criteria: 1. PSA not more than 5 ng/mL or 2. Gleason score not more than 5 or 3. A combination of the following: PSA not more than 25 ng/mL, Gleason score not more than 7, and negative DRE. Following these criteria should eliminate the need for pelvic lymphadenectomy in 60% of patients with newly diagnosed prostate cancer.

The role of transrectal ultrasound-guided biopsy-based staging, preoperative serum prostate-specific antigen, and biopsy Gleason score in prediction of final pathologic diagnosis in prostate cancer

OBJECTIVES

To evaluate the role of ultra sound-guided systematic and lesion-directed biopsies, biopsy gleason score, preoperative serum prostate-specific antigen (PSA) as three objective and reproducible variables to provide a reliable combination in preoperative identification of risk of extraprostatic extension in patients with clinically localized prostate cancer.

METHODS

The case records of 813 patients who underwent radical prostatectomy for clinically localized prostate cancer were analyzed. All had multiple systematic biopsies, two to three from each lobe, in addition to lesion-directed biopsies. Additionally, biopsies were done on seminal vesicles (SVs), if abnormal. Based on biopsy results, patients were classified as having stage B1 (T2a-T2b) or B2 (T2c) disease, depending on whether biopsies from one or both lobes were positive and stage C (T3) if there was evidence of SV involvement by biopsy of biopsies from areas of extracapsular extension as seen on transrectal ultrasound (TRUS) were positive. Logistic regression analyses with log likelihood chi-square test was used to define the correlation between individual as well as combination of preoperative variables and pathologic stage.

RESULTS

On final pathologic examination, 473 (58%) patients had organ-confined disease, 188 (23%) had extracapsular extension (ECE), with or without positive surgical margins, and 72 (9%) had SV involvement. Eighty (10%) patients had pelvic lymph node metastases. Biopsy-based staging was superior to clinical staging in predicting final pathologic diagnosis. Logistic regression analyses revealed that the combination of biopsy-based stage, preoperative serum PSA, and biopsy Gleason score provided the best prediction of final pathologic stage. Probability plots constructed with these data can provide significant information on risk of extraprostatic extension in individual patients.

CONCLUSIONS

This study demonstrates that TRUS-guided systematic biopsy in combination with preoperative serum PSA and biopsy Gleason score may provide a cost-effective approach for management decisions and prognostication in patients with prostate cancer.

Should we reconsider the indications for ileo-obturator node dissection with localized prostate cancer?

OBJECTIVE

To evaluate the need for ileo-obturator node dissection in patients with localized prostate cancer who are undergoing radical retropubic prostatectomy.

PATIENTS AND METHODS

Over a 5-year-period, 95 patients underwent bilateral pelvic lymphadenectomy. Ninety were performed in association with planned radical prostatectomy and five were staging procedures in clinical stage T3 patients prior to radiotherapy or hormonal therapy. The patients with localized prostate cancer were stage T1a (one patient), T1b (21), T2a (30), and T2b (38). Pre-operative biopsies in the patients with localized cancer were well differentiated in 44 patients, moderately well differentiated in 45 and poorly differentiated in one. In the patients with T3 tumours, pre-operative biopsies were well differentiated in one, moderately well differentiated in two and poorly differentiated in two. Prostate-specific antigen (PSA) levels ranged from 0.4 to 110.1 ng/mL (Hybritech assay).

RESULTS

Two patients had positive lymph node dissections on fixed section. These two patients had well-differentiated T1b disease with a PSA level of 72.4 ng/mL and poorly differentiated T3 disease with a PSA level of 58.5 ng/mL. There was significant upstaging (P < 0.001) and upgrading (P < 0.001) on pathological examination. None of the 71 patients with a PSA < or = 10 ng/mL had positive lymph nodes compared with 8.3% of the 24 patients with a PSA > 10 ng/mL (P = 0.0618). Lymph node metastases were present in 1% of patients with well or moderately well-differentiated prostate cancer on pre-operative biopsy versus 33% with poorly differentiated disease (P = 0.0625). These P values strongly suggest an association, achieving significance only at the 10% level which might be the more appropriate level given the relative lack of power of the study due to the small number of patients with positive lymph nodes.

CONCLUSION

These results suggest that routine ileo-obturator node dissection in patients with well or moderately well-differentiated, localized prostate cancer and a PSA level < 10 ng/mL may be unnecessary, especially as a separate procedure.

Utility of preoperative serum prostate-specific antigen concentration and biopsy Gleason score in predicting risk of pelvic lymph node metastases in prostate cancer

OBJECTIVES

To determine the accuracy of the preoperative serum concentration of prostate-specific antigen (PSA) plus the Gleason pathology score of biopsy specimens in predicting the presence of disease in the pelvic lymph nodes in patients with prostate cancer.

METHODS

The medical records of all patients treated for prostate cancer at eight medical centers from January 1988 to June 1993 were reviewed. There were 932 patients with newly diagnosed prostate cancer for whom all relevant data were available who had undergone pelvic lymphadenectomy with (n = 912) or without (n = 20) radical prostatectomy. The rate of false-negative predictions of metastases based on combined preoperative biopsy Gleason score and serum PSA concentration was analyzed. A multivariate logistic regression analysis was performed to assess the value of preoperative serum PSA and biopsy Gleason scores individually and in combination in predicting pelvic lymph node metastases.

RESULTS

The false-negative rate of metastases was 0% for preoperative PSA concentrations < or = 6 ng/mL and biopsy Gleason scores < or = 5 (n = 142) and 1.0% for PSA concentrations < or = 10 ng/mL and Gleason scores < or = 6 (n = 388). The 95% upper confidence limit for the rate of false negativity at this PSA cut-off level was 2.0%. A combination of preoperative serum PSA levels and biopsy Gleason scores provided the best prediction for the false-negative rates.

CONCLUSIONS

For patients with newly diagnosed prostate cancer who have biopsy Gleason scores < or = 6 and preoperative PSA concentrations < or = 10 ng/mL (42% of our series), a staging pelvic lymphadenectomy appears to be unnecessary. The substantial cost associated with both cross-sectional imaging and staging lymphadenectomy may therefore be avoidable in this group of patients.