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Radical Prostatectomy: Is Complete Resection of the Seminal Vesicles Really Necessary?
0022-5347/96/1563-1081$03.00/0
THEJOIXYAI.
Vol. 156,1081-1083,September 1996 Printed in U.S.A.
O F UROI.O(N
Copyright 0 1996 by AMERICAN UROLOCICAL ASSOCIATION, INC.
RADICAL PROSTATECTOMY: IS COMPLETE RESECTION OF THE SEMINAL VESICLES REALLY NECESSARY? HOWARD J. KORMAN, ROGER B. WATSON, FRANCISCO CIVANTOS, NORMAN L. BLOCK MARK S. SOLOWAY From the Departments
of
AND
Urology and Pathology, University of Miami School of Medicine, Miami, Florida
ABSTRACT
Purpose: We determined the frequency of prostate cancer extension into the distal 1 cm. of seminal vesicles, and reconsidered whether complete excision of the seminal vesicles during radical prostatectomy is always necessary. Materials and Methods: After en bloc removal with the specimen in 7 1 consecutive radical prostatectomies, the distal 1cm. of each seminal vesicle was transected and separately analyzed for tumor involvement. Results: Mean patient age was 61.8 years (range 40 to 72). Preoperative prostate specific antigen (PSA)ranged from 0.8 to 37 ng./dl. (median 7.3), and 18 patients had a PSA of 10 or more. Clinical stages were T l b in 1 case T l c i n 37, T2a in 12, T2b in 10, T2c in 6 and T3a in 1. Preoperative Gleason sums ranged from 4 to 8 (median 6) with 21 patients (30%) having a sum of 7 or more. Of 7 1 patients 12 (17%) had seminal vesicle invasion (5 bilaterally). In no case did tumor extend into the distal 1cm. of the seminal vesicle. PSA at diagnosis ranged from 4.2 to 30 ng./dl., with 4 of 12 patients having a PSA of 10 or more. Preoperative clinical stages were T l c in 5 cases, T2a in 3, T2b in 2 and T2c in 2. Five of the 12 patients (42%) had positive surgical margins and 11(92%) had a postoperative Gleason sum of 7 or more. Conclusions: I n 7 1consecutive patients undergoing radical prostatectomy no tumor was found in the distal 1 cm. of the seminal vesicles, including 12 with seminal vesicle invasion. We continue to advocate complete excision of the seminal vesicles during radical prostatectomy. However, if dissection is difficult and a small fragment is left behind, the prognosis is unlikely to be altered. KEYWORDS:prostatic neoplasms, seminal vesicles, prostatectomy A of figure), and the distal 1 cm. of each seminal vesicle was transected and separately analyzed for tumor (part B of figure). Specimens were processed using a technique similar to that described by True.5 The specimen was weighed and measured, the entire surface was inked, and the gland was fixed in 4C buffered zinc formalin for 24 hours for each 3 cm. of dimension. The bladder neck and apical margins were amputated and perpendicularly sectioned relative to the margins. The rest of the prostate was serially sectioned at 2 to 3 mm. intervals in a frontal plane. Tissue slices were subdivided into quarters and labeled to allow for reconstruction as whole mount sections. Depending on the specimen, 26 to 40 blocks were produced, which were further processed using a previously reported technique, and stained with hematoxylin and eosin.6 The percentage of cut prostate surface involved with tumor was assessed in most cases. Seminal vesicle invasion was defined as invasion of the muscular wall of the seminal vesicle as described by Epstein et al.7 Soft tissue invasion around the seminal vesicle, which has been shown to have a different clinical course than actual invasion into the muscular wall of the seminal vesicles, was considered a separate entity.3.7 Pathological tissue was analyzed with attention to seminal vesicle involvement at the MATERIALS AND METHODS base and transected distal segments, extent and location of Standard radical retropubic prostatectomy was performed concurrent positive margins, extracapsular extension and on 71 consecutive patients at our institution between April Gleason sums. Patients with seminal vesicle involvement and October 1995.The specimens were removed en bloc (part were considered to have extracapsular extension by d e w tion. Preoperative clinical stages were assigned based on the TNM classification.8 Accepted for publication March 22, 1996.
Since its original description in 1905 by Young,' radical prostatectomy has classically included total en bloc removal of the seminal vesicles. Studies have shown seminal vesicle invasion in 20 to 26%of radical prostatectomy specimen^.^-^ However, the exact mechanism of tumor spread into the seminal vesicles was not elucidated until recently. In 1990 Villers et a1 reported that in 46 of 47 cases of seminal vesicle invasion the tumor spread directly from the mid base of the prostate along and between the ejaculatory ducts.2In only 1 case (an extensive poorly differentiated carcinoma) was the focus of seminal vesicle invasion not contiguous to the primary cancer.2 Ohori et a1 proposed 3 different mechanisms of spread: 1) extension along the ejaculatory duct complex, 2) extension through the capsule of the prostate and into the muscular coat of the seminal vesicles, and 3) isolated deposits of cancer within the seminal vesicles with no contiguous primary tumor.3 Dissection of the distal seminal vesicles, the segment furthest from the base of the prostate, is occasionally difficult. We determined the frequency of tumor in this portion of the seminal vesicles, and considered whether complete excision of the seminal vesicles is always necessary.
1081
1082
SEMINAL VESICLE RESECTION AND RADICAL PROSTATECTOMY
Radical rostatectomy specimens immediately &r no case di8 distal segment contain tumor.
surgical removal (A) and after transection of distal segment of seminal vesicles (B).In
RESULTS
A total of 71 specimens was evaluated. Mean patient age was 61.8 years (range 40 to 72). Prostate specific antigen (PSA) at diagnosis ranged from 0.8 to 37 ng./dl. (median 7.3, mean 10.0) using the Hybritech assay. Of the patients 18had a PSA of 10 ng./dl. or more. Clinical disease stages were T l b in 1case, T l c in 37, T2a in 12, T2b in 10, T2c in 6 and T3a in 1. Preoperative biopsy Gleason sums ranged from 4 to 8 (median 61, with 21 of 71 patients (30%)having a sum of 7 or more. Of the 71 patients 12 (17%) had seminal vesicle invasion (5 bilaterally). In no case did tumor extend into the distal 1cm. of the seminal vesicles. Preoperative PSA in patients with seminal vesicle invasion ranged from 4.2 to 30 ng./dl. (median 6.71, and 4 of the 12 had a PSA of 10 or more. Preoperative disease stages for these patients were Tlc in 5, T2a in 3, T2b in 2 and T2c in 2. Positive surgical margins occurred in 5 of 12 patients (42%) with seminal vesicle invasion and 3 of 5 (60%) with bilateral seminal vesicle involvement. The positive margins were apical and posterior in 1patient, apical only in 1, posterior only in 2 and in the bladder neck in 1. For patients without seminal vesicle invasion the positive margin rate was 27% (see table). Postoperative Gleason sums were 7 or more in 92% of patients with compared to only 44% without seminal vesicle invasion. Of patients with seminal vesicle invasion 88% had 20% or more (range 5 to 40, median 20) of the cut surface involved with tumor, compared t o 30% (range 1to 50, median 10, see table) of those without seminal vesicle invasion. Two of 5 patients with followup PSA had detectable levels. No patient in the entire study group had positive lymph nodes. Mean number of lymph nodes sampled was 7 (range 3 to 12). DISCUSSION
Radical prostatectomy has historically included complete removal of the seminal vesicles. Villers et a1 noted that tumors smaller than 12 cc had less than 16%involvement of the seminal vesicles (based on a n exponential scale devised to simplify data analysis).2 The length of the seminal vesicles Comparison of positive surgical margins, Gleason sums and percentage of tumor involvement based on seminal vesicle invasion No. Pts~TotalNo.
POS.surgical margins Gleason sum 7 or more More than 204 tumor involvement
(a)
Seminal Vesicle Invasion
No Seminal Vesicle Invasion
5/12 (42) 11/12 (92)
13/59 (27) 26/59 (44) 13/44 (30)
718 (88)
ranged from 2.5 to 4 cm. Thus, they postulated that if less than 16% of the seminal vesicle has tumor infiltration, it will almost always be confined to the proximal 1 cm. where it enters the base of the prostate. If more than this proximal 1 cm. is involved a tumor volume of more than 12 cc and a significant likelihood of extensive extracapsular disease with positive margins elsewhere can be predicted.2. We attempted to determine if removal of the entire seminal vesicle is necessary for complete tumor resection. Practically speaking, can we remove only part of the seminal vesicle just as we remove only part of the vasa deferentia? Towards this end, we separately analyzed the distal 1cm. of each seminal vesicle in 71 consecutive radical prostatectomy specimens. A total of 12 patients had seminal vesicle involvement but in no case was the distal 1cm. involved with tumor. Thus, none of our patients would have had tumor left behind had we partially removed the seminal vesicles. Alternatively, if tumor spreads to the seminal vesicles in a noncontiguous fashion, then partial transection could compromise the curative intent of the procedure. Ohori et a1 indicated that this event can occur occasionally.3 However, to our knowledge no study has separately analyzed the distal seminal vesicle tips to identify precisely where such noncontiguous lesions occur. A larger series may yield additional information. Leakage of prostatic secretions during radical prostatectomy has been suggested as a possible mechanism of local recurrence. Kassabian et a1 performed cytological evaluation of prostatic secretions from 76 stages T1 and T2 radical prostatectomy specimens.1° Malignant cells were found in 11 of 76 cases (14%), including 6 of 11(55%)with Gleason sums 8 to 10 but only 4 of 63 (6%)with Gleason sums 5 to 7 tumor. They postulated that malignant cells shed during radical prostatectomy could be responsible for some cases of local recurrence. Similarly, Abi Aad et a1 reported that 2 of 30 patients had malignant cells in the seminal and prostatic fluid secretions, and both had seminal vesicle invasion.11 Thus, leakage of seminal fluid into the wound with seminal vesicle transection could theoretically increase the risk of tumor recurrence. However, based on these studies, the risk of spillage of malignant cells would be only approximately 1 to 14%. CONCLUSIONS
We evaluated the degree of seminal vesicle invasion in 71 consecutive patients undergoing radical prostatectomy. In no case was the distal 1 cm. of the seminal vesicles involved, including all 12 with seminal vesicle invasion. We continue to recommend complete en bloc removal of the seminal vesicles at radical prostatectomy. However, if dissection is difficult
SEMINAL VESICLE RESECTION AND RADICAL PROSTATECTOMY and a small fragment of seminal vesicle is left behind, it is
unlikely that prognosis will be altered. REFERENCES
1. Young, H. H.: The early diagnosis and radical cure of carcinoma of the prostate: being a study of 40 cases and presentation of a radical operation which was carried out in four cases. Bull. Johns Hopkins Hosp., 1 6 315, 1905. 2. Villers, A. A.. McNeal. J . E., Redwine, E. A,, Freiha, F. S. and Stamey, T. A.: Pathogenesis and biological significance of seminal vesicle invasion in prostatic adenocarcinoma. J. Urol., 143 1183, 1990. 3. Ohori, M.,Scardino. P. T., Lapin, S. L., Seale-Hawkins, C., Link, J. and Wheeler, T. M.: The mechanisms and prognostic significnnce of seminal vesicle involvement by prostate cancer. Amer. J. Surg. Path., 17: 1252, 1993. 4. Mukamcl, E., deKernion. J. B., Hannah, J., Smith, R. B., Skinner, D. G . and Goodwin, W. E.: The incidence and significance of seminal vesicle invasion in patients with adenocarcinoma of the prostate. Cancer, 5 9 1535,1987. 5. True, L. I).: Surgical pathology examination of the prostate gland. Practice survey by American Society of Clinical Pathologists. Amer. J . Clin. Path., 102 572. 1994.
1083
6. Civantos, F., Marcial, M. A., Banks, E. R., Ho, C. EL, Speights, D. O., Drew, P. A., Murphy, W. M. and Soloway, M. S.: Pathology of androgen deprivation therapy in prostate carcinoma. Cancer, 75 1634,1995. 7. Epstein, J.I., Carmichael, M. and Walsh, P. C.: Adenocarcinoma of the prostate invadmg the seminal vesicle: definition and relation of tumor volume, grade and margins of resection to prognosis. J. Urol.,149 1040,1993. 8. Schriider, F. H., Hermanek, P., Denis, L., Fair, W. R., Gospodarowicz, M. K and Pavone-Macaluso, M.: The TNM classification of prostate cancer. Prostate, suppl., 4 129,1992. 9. McNeal, J. E., Vilers, A. A, Redwine, E. A., Freiha, F. S. and Stamey, T. A.: Capsular penetration in prostate cancer: sigmficance for natural history and treatment. Amer. J. Surg. Path., 14 240, 1990. 10. Kassabian, V. S., Bottles, K., Weaver, R., Williams, R. D., Paulson, D. F. and Scardino, P. T.: Possible mechanism for seeding of tumor during radical prostatectomy. J. Urol., 190: 1169,1993. 11. Abi Aad, A. S., No&l,H.. Lorge, F., Wese, F. X., Opsomer, R. J. and Van Cangh, P. J.: Do seminal or prostatic secretions play a role in local recurrence after radical prostatectomy for localized prostate cancer? Eur. Urol., 24: 471, 1993.
THEJOIXYAI.
Vol. 156,1081-1083,September 1996 Printed in U.S.A.
O F UROI.O(N
Copyright 0 1996 by AMERICAN UROLOCICAL ASSOCIATION, INC.
RADICAL PROSTATECTOMY: IS COMPLETE RESECTION OF THE SEMINAL VESICLES REALLY NECESSARY? HOWARD J. KORMAN, ROGER B. WATSON, FRANCISCO CIVANTOS, NORMAN L. BLOCK MARK S. SOLOWAY From the Departments
of
AND
Urology and Pathology, University of Miami School of Medicine, Miami, Florida
ABSTRACT
Purpose: We determined the frequency of prostate cancer extension into the distal 1 cm. of seminal vesicles, and reconsidered whether complete excision of the seminal vesicles during radical prostatectomy is always necessary. Materials and Methods: After en bloc removal with the specimen in 7 1 consecutive radical prostatectomies, the distal 1cm. of each seminal vesicle was transected and separately analyzed for tumor involvement. Results: Mean patient age was 61.8 years (range 40 to 72). Preoperative prostate specific antigen (PSA)ranged from 0.8 to 37 ng./dl. (median 7.3), and 18 patients had a PSA of 10 or more. Clinical stages were T l b in 1 case T l c i n 37, T2a in 12, T2b in 10, T2c in 6 and T3a in 1. Preoperative Gleason sums ranged from 4 to 8 (median 6) with 21 patients (30%) having a sum of 7 or more. Of 7 1 patients 12 (17%) had seminal vesicle invasion (5 bilaterally). In no case did tumor extend into the distal 1cm. of the seminal vesicle. PSA at diagnosis ranged from 4.2 to 30 ng./dl., with 4 of 12 patients having a PSA of 10 or more. Preoperative clinical stages were T l c in 5 cases, T2a in 3, T2b in 2 and T2c in 2. Five of the 12 patients (42%) had positive surgical margins and 11(92%) had a postoperative Gleason sum of 7 or more. Conclusions: I n 7 1consecutive patients undergoing radical prostatectomy no tumor was found in the distal 1 cm. of the seminal vesicles, including 12 with seminal vesicle invasion. We continue to advocate complete excision of the seminal vesicles during radical prostatectomy. However, if dissection is difficult and a small fragment is left behind, the prognosis is unlikely to be altered. KEYWORDS:prostatic neoplasms, seminal vesicles, prostatectomy A of figure), and the distal 1 cm. of each seminal vesicle was transected and separately analyzed for tumor (part B of figure). Specimens were processed using a technique similar to that described by True.5 The specimen was weighed and measured, the entire surface was inked, and the gland was fixed in 4C buffered zinc formalin for 24 hours for each 3 cm. of dimension. The bladder neck and apical margins were amputated and perpendicularly sectioned relative to the margins. The rest of the prostate was serially sectioned at 2 to 3 mm. intervals in a frontal plane. Tissue slices were subdivided into quarters and labeled to allow for reconstruction as whole mount sections. Depending on the specimen, 26 to 40 blocks were produced, which were further processed using a previously reported technique, and stained with hematoxylin and eosin.6 The percentage of cut prostate surface involved with tumor was assessed in most cases. Seminal vesicle invasion was defined as invasion of the muscular wall of the seminal vesicle as described by Epstein et al.7 Soft tissue invasion around the seminal vesicle, which has been shown to have a different clinical course than actual invasion into the muscular wall of the seminal vesicles, was considered a separate entity.3.7 Pathological tissue was analyzed with attention to seminal vesicle involvement at the MATERIALS AND METHODS base and transected distal segments, extent and location of Standard radical retropubic prostatectomy was performed concurrent positive margins, extracapsular extension and on 71 consecutive patients at our institution between April Gleason sums. Patients with seminal vesicle involvement and October 1995.The specimens were removed en bloc (part were considered to have extracapsular extension by d e w tion. Preoperative clinical stages were assigned based on the TNM classification.8 Accepted for publication March 22, 1996.
Since its original description in 1905 by Young,' radical prostatectomy has classically included total en bloc removal of the seminal vesicles. Studies have shown seminal vesicle invasion in 20 to 26%of radical prostatectomy specimen^.^-^ However, the exact mechanism of tumor spread into the seminal vesicles was not elucidated until recently. In 1990 Villers et a1 reported that in 46 of 47 cases of seminal vesicle invasion the tumor spread directly from the mid base of the prostate along and between the ejaculatory ducts.2In only 1 case (an extensive poorly differentiated carcinoma) was the focus of seminal vesicle invasion not contiguous to the primary cancer.2 Ohori et a1 proposed 3 different mechanisms of spread: 1) extension along the ejaculatory duct complex, 2) extension through the capsule of the prostate and into the muscular coat of the seminal vesicles, and 3) isolated deposits of cancer within the seminal vesicles with no contiguous primary tumor.3 Dissection of the distal seminal vesicles, the segment furthest from the base of the prostate, is occasionally difficult. We determined the frequency of tumor in this portion of the seminal vesicles, and considered whether complete excision of the seminal vesicles is always necessary.
1081
1082
SEMINAL VESICLE RESECTION AND RADICAL PROSTATECTOMY
Radical rostatectomy specimens immediately &r no case di8 distal segment contain tumor.
surgical removal (A) and after transection of distal segment of seminal vesicles (B).In
RESULTS
A total of 71 specimens was evaluated. Mean patient age was 61.8 years (range 40 to 72). Prostate specific antigen (PSA) at diagnosis ranged from 0.8 to 37 ng./dl. (median 7.3, mean 10.0) using the Hybritech assay. Of the patients 18had a PSA of 10 ng./dl. or more. Clinical disease stages were T l b in 1case, T l c in 37, T2a in 12, T2b in 10, T2c in 6 and T3a in 1. Preoperative biopsy Gleason sums ranged from 4 to 8 (median 61, with 21 of 71 patients (30%)having a sum of 7 or more. Of the 71 patients 12 (17%) had seminal vesicle invasion (5 bilaterally). In no case did tumor extend into the distal 1cm. of the seminal vesicles. Preoperative PSA in patients with seminal vesicle invasion ranged from 4.2 to 30 ng./dl. (median 6.71, and 4 of the 12 had a PSA of 10 or more. Preoperative disease stages for these patients were Tlc in 5, T2a in 3, T2b in 2 and T2c in 2. Positive surgical margins occurred in 5 of 12 patients (42%) with seminal vesicle invasion and 3 of 5 (60%) with bilateral seminal vesicle involvement. The positive margins were apical and posterior in 1patient, apical only in 1, posterior only in 2 and in the bladder neck in 1. For patients without seminal vesicle invasion the positive margin rate was 27% (see table). Postoperative Gleason sums were 7 or more in 92% of patients with compared to only 44% without seminal vesicle invasion. Of patients with seminal vesicle invasion 88% had 20% or more (range 5 to 40, median 20) of the cut surface involved with tumor, compared t o 30% (range 1to 50, median 10, see table) of those without seminal vesicle invasion. Two of 5 patients with followup PSA had detectable levels. No patient in the entire study group had positive lymph nodes. Mean number of lymph nodes sampled was 7 (range 3 to 12). DISCUSSION
Radical prostatectomy has historically included complete removal of the seminal vesicles. Villers et a1 noted that tumors smaller than 12 cc had less than 16%involvement of the seminal vesicles (based on a n exponential scale devised to simplify data analysis).2 The length of the seminal vesicles Comparison of positive surgical margins, Gleason sums and percentage of tumor involvement based on seminal vesicle invasion No. Pts~TotalNo.
POS.surgical margins Gleason sum 7 or more More than 204 tumor involvement
(a)
Seminal Vesicle Invasion
No Seminal Vesicle Invasion
5/12 (42) 11/12 (92)
13/59 (27) 26/59 (44) 13/44 (30)
718 (88)
ranged from 2.5 to 4 cm. Thus, they postulated that if less than 16% of the seminal vesicle has tumor infiltration, it will almost always be confined to the proximal 1 cm. where it enters the base of the prostate. If more than this proximal 1 cm. is involved a tumor volume of more than 12 cc and a significant likelihood of extensive extracapsular disease with positive margins elsewhere can be predicted.2. We attempted to determine if removal of the entire seminal vesicle is necessary for complete tumor resection. Practically speaking, can we remove only part of the seminal vesicle just as we remove only part of the vasa deferentia? Towards this end, we separately analyzed the distal 1cm. of each seminal vesicle in 71 consecutive radical prostatectomy specimens. A total of 12 patients had seminal vesicle involvement but in no case was the distal 1cm. involved with tumor. Thus, none of our patients would have had tumor left behind had we partially removed the seminal vesicles. Alternatively, if tumor spreads to the seminal vesicles in a noncontiguous fashion, then partial transection could compromise the curative intent of the procedure. Ohori et a1 indicated that this event can occur occasionally.3 However, to our knowledge no study has separately analyzed the distal seminal vesicle tips to identify precisely where such noncontiguous lesions occur. A larger series may yield additional information. Leakage of prostatic secretions during radical prostatectomy has been suggested as a possible mechanism of local recurrence. Kassabian et a1 performed cytological evaluation of prostatic secretions from 76 stages T1 and T2 radical prostatectomy specimens.1° Malignant cells were found in 11 of 76 cases (14%), including 6 of 11(55%)with Gleason sums 8 to 10 but only 4 of 63 (6%)with Gleason sums 5 to 7 tumor. They postulated that malignant cells shed during radical prostatectomy could be responsible for some cases of local recurrence. Similarly, Abi Aad et a1 reported that 2 of 30 patients had malignant cells in the seminal and prostatic fluid secretions, and both had seminal vesicle invasion.11 Thus, leakage of seminal fluid into the wound with seminal vesicle transection could theoretically increase the risk of tumor recurrence. However, based on these studies, the risk of spillage of malignant cells would be only approximately 1 to 14%. CONCLUSIONS
We evaluated the degree of seminal vesicle invasion in 71 consecutive patients undergoing radical prostatectomy. In no case was the distal 1 cm. of the seminal vesicles involved, including all 12 with seminal vesicle invasion. We continue to recommend complete en bloc removal of the seminal vesicles at radical prostatectomy. However, if dissection is difficult
SEMINAL VESICLE RESECTION AND RADICAL PROSTATECTOMY and a small fragment of seminal vesicle is left behind, it is
unlikely that prognosis will be altered. REFERENCES
1. Young, H. H.: The early diagnosis and radical cure of carcinoma of the prostate: being a study of 40 cases and presentation of a radical operation which was carried out in four cases. Bull. Johns Hopkins Hosp., 1 6 315, 1905. 2. Villers, A. A.. McNeal. J . E., Redwine, E. A,, Freiha, F. S. and Stamey, T. A.: Pathogenesis and biological significance of seminal vesicle invasion in prostatic adenocarcinoma. J. Urol., 143 1183, 1990. 3. Ohori, M.,Scardino. P. T., Lapin, S. L., Seale-Hawkins, C., Link, J. and Wheeler, T. M.: The mechanisms and prognostic significnnce of seminal vesicle involvement by prostate cancer. Amer. J. Surg. Path., 17: 1252, 1993. 4. Mukamcl, E., deKernion. J. B., Hannah, J., Smith, R. B., Skinner, D. G . and Goodwin, W. E.: The incidence and significance of seminal vesicle invasion in patients with adenocarcinoma of the prostate. Cancer, 5 9 1535,1987. 5. True, L. I).: Surgical pathology examination of the prostate gland. Practice survey by American Society of Clinical Pathologists. Amer. J . Clin. Path., 102 572. 1994.
1083
6. Civantos, F., Marcial, M. A., Banks, E. R., Ho, C. EL, Speights, D. O., Drew, P. A., Murphy, W. M. and Soloway, M. S.: Pathology of androgen deprivation therapy in prostate carcinoma. Cancer, 75 1634,1995. 7. Epstein, J.I., Carmichael, M. and Walsh, P. C.: Adenocarcinoma of the prostate invadmg the seminal vesicle: definition and relation of tumor volume, grade and margins of resection to prognosis. J. Urol.,149 1040,1993. 8. Schriider, F. H., Hermanek, P., Denis, L., Fair, W. R., Gospodarowicz, M. K and Pavone-Macaluso, M.: The TNM classification of prostate cancer. Prostate, suppl., 4 129,1992. 9. McNeal, J. E., Vilers, A. A, Redwine, E. A., Freiha, F. S. and Stamey, T. A.: Capsular penetration in prostate cancer: sigmficance for natural history and treatment. Amer. J. Surg. Path., 14 240, 1990. 10. Kassabian, V. S., Bottles, K., Weaver, R., Williams, R. D., Paulson, D. F. and Scardino, P. T.: Possible mechanism for seeding of tumor during radical prostatectomy. J. Urol., 190: 1169,1993. 11. Abi Aad, A. S., No&l,H.. Lorge, F., Wese, F. X., Opsomer, R. J. and Van Cangh, P. J.: Do seminal or prostatic secretions play a role in local recurrence after radical prostatectomy for localized prostate cancer? Eur. Urol., 24: 471, 1993.