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Biomedical subjects

J J Bauer

Publications and source records attributed to J J Bauer.

At least 19 recordsLinked to original sources
PubMed1999

Prostate-specific antigen to predict outcome of external beam radiation for prostate cancer: Walter Reed Army Medical Center experience, 1988-1995.

OBJECTIVES: To assess the ability of pretreatment and post-treatment prostate-specific antigen (PSA) measurements, clinical tumor stage, tumor grade, Gleason sum, race, age, and radiation dose to predict the recurrence of prostate cancer following external beam radiation therapy (XRT) since the introduction of PSA as a tumor marker at one tertiary care center. METHODS: The recurrence of prostate cancer among 371 evaluable patients of 389 patients treated with XRT at Walter Reed Army Medical Center was analyzed using Kaplan-Meier survival methodology and Cox multivariable regression models. Serologic (PSA) recurrence was determined using three consecutive rises in PSA after a nadir value. Clinical recurrence was defined as local recurrence (palpable or positive biopsy) and/or distant (radiographically evident) recurrence. Mean and median follow-up is 40.2 and 39.4 months, respectively (range 3.0 to 89.5), and minimum follow-up is 18 months for patients who were alive at the time of analysis. No patient received adjuvant hormonal therapy. Potential prognostic factors evaluated are pretreatment PSA, PSA nadir, age, race, clinical tumor stage, tumor grade, Gleason sum, and radiation dose. RESULTS: Of the 371 evaluable patients, 125 had disease recurrence. The Kaplan-Meier 5-year disease-free survival (DFS) rates for significant pretreatment variables in univariate analyses are as follows: pretreatment PSA less than 4 (79%), 4.1 to 10 (67%), 10.1 to 20 (57%), 20.1 to 50 (27%), and more than 50 (0%); for clinical tumor Stage T1a-T1c (84%), T2a-T2c (51 %), and T3-T4 (29%); for tumor grade well (58%), moderate (58%), and poor (30%). Four-year DFS rates for Gleason sum are 2 to 4 (82%), 5 (72%), 6 (56%), and 7 to 10 (48%). In multivariable Cox regression analysis with backward elimination of nonsignificant variables, age, race, tumor grade, and radiation dose were eliminated, leaving pretreatment PSA, clinical tumor stage, and Gleason sum as significant prognostic factors. Analysis of a Cox model that included nadir PSA as a time-dependent variable showed it to be the strongest prognostic factor variable in the analysis. CONCLUSIONS: XRT remains a suitable treatment modality for patients with pretreatment PSA less than 20.0, clinical tumor Stages T1-T2, and Gleason sum 2 to 6 prostate cancer. Patients achieving a nadir value less than 0.5 have more durable treatment outcomes.

Aged↗
PubMed1999

Three-dimensional computer-simulated prostate models: lateral prostate biopsies increase the detection rate of prostate cancer.

OBJECTIVES: Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error. We developed a novel three-dimensional (3D) computer-assisted prostate biopsy simulator based on whole-mounted step-sectioned radical prostatectomy specimens to compare the diagnostic accuracy of various prostate needle biopsy protocols. METHODS: We obtained digital images of 201 step-sectioned whole-mounted radical prostatectomy specimens. 3D computer simulation software was developed to accurately depict the anatomy of the prostate and all individual tumor foci. Additional peripheral devices were incorporated into the system to perform interactive prostate biopsies. We obtained 18 biopsies of each prostate model to determine the detection rates of various biopsy protocols. RESULTS: The 10- and 12-pattern biopsy protocols had a 99.0% detection rate; the traditional sextant biopsy protocol rate was only 72.6%. The 5-region biopsy protocol had a 90.5% detection rate and the 14-pattern, which includes all the biopsies used in the patterns above, only added 1 additional positive case (99.5%). Transitional zone and seminal vesicle biopsies did not result in a significantly increased detection rate when added to the patterns above. Only one positive model was obtained when the transitional zone biopsies were added. The lateral sextant pattern had a detection rate of 95.5%, and the 4-pattern lateral biopsy protocol had a 93.5% detection rate. CONCLUSIONS: Our results suggest that all the biopsy protocols that use laterally placed biopsies based on the 5-region anatomic model are superior to the routinely used sextant prostate biopsy pattern. Lateral biopsies in the mid and apical zones of the gland are the most important.

Biopsy, Needle↗
PubMed1999

Twelve-year experience with expanded polytetrafluoroethylene in the repair of abdominal wall defects.

BACKGROUND: A prosthetic device must be used to repair ventral hernias in patients with insufficient tissue for a tension-free primary closure. Several prosthetic materials have been employed for this purpose, with varying results. We here review a long experience with the use of expanded polytetrafluoroethylene (ePTFE) patches in the open repair of large abdominal wall defects. METHODS: Demographic, operative, follow-up, and histologic data were recorded and analyzed for all patients in a surgical practice who were treated for large abdominal wall defects with open repair using ePTFE patches between November 1983 and March 1996. RESULTS: Ventral hernia repairs using an ePTFE patch were performed in 98 patients. In 48 (49%), the patient had already undergone at least one previous ventral hernia repair. Of the 98 operations, 78 were full-thickness repairs, 11 were Rives-Stoppa procedures, and 9 were onlay operations. Complications included 5 seromas, 3 fistulas related to removal of a previously implanted prosthesis, and 9 infections. In addition, 10 patients developed recurrent hernias not related to explantation of the patch because of infection or fistula. In 3 patients, infections were treated successfully without removal of the patch. There were no complications related to adhesions, erosion of the patch into the viscera, or bowel obstruction. Histologic studies of longterm ePTFE implants showed excellent fibrous tissue ingrowth and minimal foreign body response. CONCLUSIONS: Our long-term clinical experience indicates that prosthetic patches of ePTFE are safe and effective when used in the repair of large abdominal wall defects that cannot be closed primarily. Operative complications were within acceptable limits, as was the reherniation rate.

Adult↗
PubMed1998

Perineal seeding of prostate cancer as the only evidence of clinical recurrence 14 years after needle biopsy and radical prostatectomy: molecular correlation.

Perineal needle tract seeding of prostate cancer is an unusual complication of perineal prostate biopsy. We report a case with the longest known interval from biopsy to perineal recurrence--14 years. The prostate-specific antigen did not become detectable until 12 years after biopsy and no other metastases were apparent, suggesting that the patient's perineal disease was an isolated recurrence. Immunohistochemical staining of the perineal recurrence and the original biopsy and prostate for the p53 tumor suppressor gene and bcl-2 oncogene proteins revealed rare/absent p53 expression but marked increased bcl-2 expression. This unusual molecular pedigree may help to explain this rare clinical scenario.

Aged↗
PubMed1998

Hepatic subcapsular extension of pelvic lymphocele after radical retropubic prostatectomy.

Lymphoceles are a rare symptomatic complication after radical prostatectomy occurring in less than 5% of cases. We present a case of a symptomatic lymphocele that occurred after a radical retropubic prostatectomy and obturator lymphadenectomy. The lymphocele dissected along the retroperitoneum and extended into the hepatic subcapsular space and became secondarily infected with Candida albicans.

Candidiasis↗
PubMed1998

Laparoscopy for the acute abdomen in the postoperative urologic patient.

OBJECTIVES: Exploratory laparotomy offers the greatest diagnostic accuracy of intra-abdominal pathologic processes, but can be associated with significant morbidity. Laparoscopy provides diagnostic capabilities equivalent to that of open exploration, but with potentially less morbidity. We present 3 cases in which laparoscopy was used to diagnose and manage urologic patients with an acute abdomen in a postoperative period. METHODS: Three patients underwent laparoscopy between 1 and 14 days postoperatively for an acute abdomen (fever, elevated white blood cell count, and peritoneal signs). The initial procedures included a pubovaginal sling repair with fascia lata, endoscopic placement of a percutaneous gastrostomy tube, and a laparoscopic ureterolithotomy for a distal stone. RESULTS: In each of the 3 patients laparoscopy revealed misplacement or malfunction of a previously placed tube. In all cases, the patient was managed laparoscopically without the need for laparotomy. CONCLUSIONS: These cases demonstrate the feasibility of laparoscopy to provide diagnostic and therapeutic solutions to postoperative urologic patients presenting with an acute abdomen.

Abdomen, Acute↗
PubMed1998

Significance of familial history of prostate cancer to traditional prognostic variables, genetic biomarkers, and recurrence after radical prostatectomy.

OBJECTIVES: Prostate cancer (PCa) has a familial predisposition imparting an increased risk of developing the disease in those with a family history. The pathologic characteristics are similar to sporadic cases; however, the disease-free survival rates of hereditary PCa have recently been disputed, with one major study suggesting that familial cases have higher recurrence rates. Our study seeks to support or refute this association and to evaluate the genetic biomarkers p53, bcl-2, Ki-67, and neovascularity between familial and sporadic disease. METHODS: We retrospectively reviewed data of 573 patients who underwent radical prostatectomy over an 11-year period. Of these, 474 patients had known family history data. Univariable statistical analysis using the Pearson chi-square test and Kaplan-Meier disease-free survival analysis was performed to identify any correlation between the tested variables and family history. Smaller subsets of this cohort that had available archival material for immunohistochemical staining and family history data were analyzed in a similar manner. RESULTS: The preoperative variables (prostate-specific antigen, prostatic acid phosphatase, clinical stage, highest biopsy Gleason sum, and glandular differentiation) and postoperative variables (stage, highest Gleason sum, and glandular differentiation) did not correlate with family history. Kaplan-Meier disease-free survival analysis revealed no differences between sporadic and familial cases. The analysis of p53, bcl-2, Ki-67, and angiogenesis revealed that only increasing p53 expression and positive family history of PCa approached significance (P = 0.057). CONCLUSIONS: Prognostic variables routinely used in PCa and selected genetic biomarker immunostaining abnormalities are not significantly different in men with and without a family history of PCa. Disease-free survival after radical prostatectomy is also unaffected by family history.

Aged↗
PubMed1998

Biostatistical modeling using traditional preoperative and pathological prognostic variables in the selection of men at high risk for disease recurrence after radical prostatectomy for prostate cancer.

PURPOSE: Biostatistical models predicting the risk of recurrence after radical prostatectomy for clinically localized prostate cancer are necessary. Identifying these high risk patients shortly after surgery, while tumor burden is minimal, makes them candidates for possible adjuvant therapy and/or investigational phase II clinical trials. This study builds on previously proposed models that predict the likelihood of early recurrence after radical prostatectomy. MATERIALS AND METHODS: In our analysis we evaluate age, race, prostatic acid phosphatase and nuclear grade with the established prognostic variables of pretreatment prostate specific antigen, postoperative Gleason sum and pathological stage. RESULTS: After multivariable Cox regression analysis using only statistically significant variables that predicted recurrence we developed an equation that calculates the relative risk of recurrence (Rr) as: Rr = exp[(0.51 x Race) + (0.12 x PSAST) + (0.25 x Postop Gleason sum) + (0.89 x Organ Conf.). These cases are then categorized into 3 distinct risk groups of relative risk of recurrence of low (< 10.0), intermediate (10.0 to 30.0) and high (> 30.0). Kaplan-Meier survival analysis of these 3 risk groups reveals that each category has significantly different risks of recurrence (p < 0.05). This model is validated with an independent cohort of radical prostatectomy patients treated at a different medical center by multiple primary surgeons. CONCLUSIONS: This model suggests that race, preoperative prostate specific antigen, postoperative Gleason sum and pathological stage are important independent prognosticators of recurrence after radical prostatectomy for clinically localized prostate cancer. Race should be considered in future models that attempt to predict the likelihood of recurrence after surgery.

Aged↗
PubMed1998

CD34 immunohistochemical assessment of angiogenesis as a prognostic marker for prostate cancer recurrence after radical prostatectomy.

PURPOSE: We assess the neovascularity of clinically localized prostate cancer by immunohistochemistry using the monoclonal antibody CD34 in an attempt to identify associations between angiogenesis and disease progression following radical prostatectomy. MATERIALS AND METHODS: Microvascularity was evaluated using the CD34 monoclonal antibody in archival paraffin embedded radical prostatectomy specimens from 149 patients followed from 3 to 10 years (mean 6.6). Vessels were quantified by counting a minimum of 2 selected microscopic fields (200x, 0.754 mm.2) from each tumor, area of prostatic intraepithelial neoplasia and prostatic hyperplasia, and given a numerical value representing the microvessel density count. RESULTS: Mean microvessel density count did not vary significantly with age or race. There was a significant association between the count and nuclear grade, Gleason sum and pathological stage. Cox survival analysis shows that microvessel density is significantly related to time to recurrence when considered as a continuous variable (p=0.03) as well as dichotomous variable (p=0.007) (microvessel density count less than 90 and 90 or greater). The 5-year recurrence-free survival was significantly higher for patients with a count less than 90 (71%) than for those with a count 90 or greater (51%) (p=0.006). The 5-year recurrence-free survival was also significantly different when microvessel density was used as a continuous variable (p=0.02). Controlling for stage, Gleason sum, race and nuclear grade, microvessel density remained significant in predicting recurrence (p=0.03) but when pretreatment prostate specific antigen was included in the model the count was no longer significant. The microvessel density count in the tumor area significantly increased with increasing Gleason sum and nuclear grade but it did not increase significantly in the adjacent benign prostate or areas of prostatic intraepithelial neoplasia in the same specimen. CONCLUSIONS: Microvascularity or neovascularity as measured by the CD34 antigen may be a prognostic marker of recurrence for prostate cancer patients after radical prostatectomy but more study in prostate specific antigen era patients with sufficient followup is needed.

Age Factors↗
PubMed1998

Statistical modeling using preoperative prognostic variables in predicting extracapsular extension and progression after radical prostatectomy for prostate cancer.

OBJECTIVE: To predict the risk of extracapsular extension and postoperative recurrence before radical prostatectomy (RP) for prostate cancer. METHODS: We performed multivariate Cox regression analysis on preoperative variables in 260 clinically localized prostate cancer patients who underwent RP. With these data, we constructed a relative risk of recurrence (Rr) equation and an equation to predict the probability of extracapsular extension (PECE) before RP. RESULTS: Rr is calculated as exp[(0.47 x race + 0.14 x PSAST) + (0.13 x worst biopsy Gleason sum) + (1.03 x stage T1c) + (1.55 x stage T2b,c)], where PSAST indicates a sigmoidal transformation of prostate-specific antigen. PECE is calculated as 1/[1 + exp(-Z)], where Z = -2.47 + 0.15 (PSAST) + 0.31 (worst biopsy Gleason sum) + 0.18 (race) + 0.16 (stage T1c) + 0.38 (stage T2b,c). CONCLUSION: These two equations can be used preoperatively to predict the probability of extracapsular disease and the risk of prostate-specific antigen recurrence in patients undergoing RP.

Aged↗
PubMed1997

Biostatistical modeling using traditional variables and genetic biomarkers for predicting the risk of prostate carcinoma recurrence after radical prostatectomy.

BACKGROUND: Approximately 50-60% of patients treated with radical prostatectomy for clinically localized prostate carcinoma are found to have microscopic disease that is not organ-confined, and a significant portion of these patients will relapse. Multiple studies have attempted to identify these high risk patients by evaluating many potential prognostic variables. These studies, however, have not included the more recent molecular biomarkers found to be independent predictors of disease recurrence. METHODS: One hundred thirty-two patients who underwent radical prostatectomy at one center between 1986 and 1993 were subjected to a multivariable Cox regression analysis to determine the preoperative and postoperative variables that remain significant predictors for the likelihood of serologic recurrence. The preoperative variables included in the model were age, race, and prostate specific antigen(PSA); the postoperative variables were Gleason sum, nuclear grade, pathologic stage (capsular status), p53 tumor suppressor gene expression, bcl-2 protooncogene expression, and proliferative biomarker Ki-67 expression. Biomarkers were also evaluated separately. RESULTS: A model was developed using only variables that remained significant predictors for the likelihood of recurrence. The following equation calculated the relative risk of recurrence: Rw = exp [(0.70 x Race) + (0.79 x PSA[4.1-10]) + (1.34 x PSA[>10]) + ( 0.91 x Organ confinement) + (0.65 x p53[1,2+]) + (1.45 x p53[3,4+]) + (0.70 x bcl-2)]. This equation categorized men into 3 distinct risk groups (low: Rr < 5.0; intermediate: Rr = 5.0-15.0; high risk: Rr > 15.0). CONCLUSIONS: This equation allows patients at high risk for PSA recurrence to be identified shortly after radical surgery. These patients at high risk for serologic recurrence and eventual progression may be considered for currently accepted adjuvant therapy or enrollment in clinical trials for the newer investigational therapies for locally advanced prostate carcinoma.

Aged↗
PubMed1997

Restorative proctocolectomy in patients older than fifty years.

PURPOSE: This study was undertaken to compare functional results, complications, preoperative durations of disease, and rates of dysplasia and neoplasia between older and younger chronic ulcerative colitis patients undergoing restorative proctocolectomy (RPC) with mucosectomy. METHODS: A total of 392 patients with a preoperative diagnosis of chronic ulcerative colitis underwent elective RPC with mucosection and handsewn ileoanal anastomosis. Pathologic reports were reviewed, with specific reference to findings of dysplasia or cancer. Functional results concerning the number of bowel movements per 24 hour period and the incidence of fecal soilage were obtained by direct or telephone patient interview. FINDINGS: Group I consisted of 326 patients aged 5 to 49 (mean, 30.9) years and 160 women. Group II comprised 66 patients aged 50 to 74 (mean, 56.9) years and 29 women. Duration of disease was significantly longer in the older group (6.2 vs. 15.6 years; P < 0.001). The older group had significantly higher rates of dysplasia (29/326 vs. 19/66; P < 0.0001) and malignancy (14/326 vs. 9/66; P = 0.003). Rates of complication, hospital days following RPC, and total hospital days for all causes were comparable between groups. Perfect day-time continence was observed in 81.6 percent of Group I and 80 percent of Group II patients (213/261 vs. 40/50; P = 0.79). Perfect continence during sleep was observed in 65.1 percent of Group I and 62 percent of Group II patients (170/261 vs. 31/50; P = 0.67). Mean number of bowel movements per 24 hour period for Group I was 6.3 +/- 0.2 and for Group II was 7.4 +/- 0.5. Mean difference, one movement per 24 hours, was not significant (95 percent confidence interval, -0.02 to 2.1; t = 1.95, P = 0.055). CONCLUSIONS: We conclude that patients older than 50 years are suitable candidates for RPC with mucosectomy. Functional results and complication rates are similar to those observed among younger patients. Patients older than 50 years have a significantly higher rate of concurrent dysplasia and malignant degeneration than younger patients, most probably because of a longer duration of disease. RPC with mucosal excision potentially lowers this risk by elimination of all colorectal mucosa.

Age Factors↗
PubMed1997

Incidence of stool guaiac conversion following extracorporeal shock wave lithotripsy.

OBJECTIVES: To study, in a prospective fashion, acute traumatic effects on the gastrointestinal tract of patients treated by extracorporeal shock wave lithotripsy (ESWL). METHODS: Stool samples from each of 54 patients were tested before and after ESWL for conversion to hemoccult positive. A minimum of one negative pre-ESWL stool guaiac test was required for inclusion into the study. A minimum of two stool guaiac tests were done after ESWL to verify negativity. Patients who converted to a positive hemoccult test after ESWL were then evaluated by colonoscopy for the source of bleeding. RESULTS: Fifty patients completed the study. A single patient (2.0%) converted to a positive post-ESWL hemoccult test and was evaluated with colonoscopy. This patient was found to have two benign adenomatous polyps in the sigmoid and descending colon after treatment for a left renal pelvis calculus. An additional patient with a slightly positive post-ESWL conversion refused further evaluation. The overall post-ESWL conversion rate to guaiac positive, therefore, was less than 4% (2 of 51 patients). CONCLUSIONS: There is no evidence of significant trauma or detectable bleeding in the normal gastrointestinal tract caused by ESWL as measured by postprocedure stool guaiac testing. Guaiac testing of the stool after ESWL may unmask pre-existing gastrointestinal disease. Therefore a positive guaiac test after ESWL warrants further evaluation. This study reaffirms that ESWL is a safe, minimally invasive technique for the treatment of urolithiasis, without significant adverse side effects on the gastrointestinal tract.

Digestive System↗
PubMed1997

Immediate radical prostatectomy for incidentally found prostate cancer after open prostatectomy for benign prostatic hyperplasia.

We describe the case report and detailed operative findings of a 57-year-old man who underwent radical retropubic prostatectomy (RRP) for incidental prostate cancer 2 weeks after open prostatectomy for benign prostatic hyperplasia (BPH). We advocate an open cystotomy at the time of RRP to identify the ureters and assure that the bladder neck margin is free of prostatic tissue. We offer this therapy as a safe curative treatment modality in the early postoperative period after prior prostate surgery.

Adenoma↗
PubMed1996

Protein expression of p53, bcl-2, and KI-67 (MIB-1) as prognostic biomarkers in patients with surgically treated, clinically localized prostate cancer.

BACKGROUND: Protein expression in the primary tumor of the tumor suppressor gene p53 and the proto-oncogene bcl-2 have been shown to be prognostic biomarkers of cancer recurrence after radical prostatectomy in patients with clinically localized prostate cancer. Cancer cell proliferation as measured by immunohistochemical markers such as the MIB-1 antibody for Ki-67 has recently been suggested to be of prognostic value in prostate cancer. The goal of this study was to determine the clinical use of p53, Ki-67 (MIB-1), and bcl-2 immunohistochemical protein expression in the primary tumor as combined predictors of disease progression after radical prostatectomy (RP). METHODS: Protein expressions of p53, Ki-67, and bcl-2 were evaluated in archival paraffin-embedded RP specimens from 162 patients monitored from 1 to 10 years (mean, 4.5 years) and correlated to stage, grade, race, and serologic (prostate-specific antigen) recurrence after operation. RESULTS: Expression was detected in 112 (69.1%), 44 (27.2%), and 62 (38.3%) of 162 patients for p53 (1+ or greater), bcl-2 (1+ or greater), and Ki-67 (2+ or greater), respectively. Biomarker expressions were not correlated to age and race; however, all increased with increasing stage and grade. The degree of expression by percentage of malignant cells staining correlated to recurrence for p53 and Ki-67 but not for bcl-2. All three markers were correlated to raw and Kaplan-Meier recurrence by means of univariate analysis with recurrence estimates at 6 years of 60.7% versus 24.2%, 84.2% versus 38.6%, and 72.4% versus 30.6% comparing positive versus negative expression of p53, bcl-2, and Ki-67, respectively. p53 and bcl-2 remained as independent prognostic markers by Cox multivariate regression analysis. Although Ki-67 did not remain an independent marker, it added prognostic use in certain subsets of patients. CONCLUSIONS: p53, bcl-2, and Ki-67 (MIB-1) appear to be important biomarkers to predict recurrence in patients with clinically localized prostate cancer after RP, and all three biomarkers deserve further study.

Aged↗
PubMed1996

Laparoscopic-assisted intestinal resection for Crohn's disease. Which patients are good candidates?

This study was undertaken to determine preoperative criteria indicating which patients with Crohn's disease are most amenable to minimally invasive intestinal resection. Laparoscopic-assisted intestinal resection was attempted in 25 patients with Crohn's disease. Preoperative assessment of all patients included physical examination and contrast radiography. Laparoscopic intestinal resection was successfully completed in 19 patients. Four patients in whom both palpable mass and fistulous disease were present required conversion to open surgery. One patient found during surgery to have a fistula required conversion, as did one patient who had undergone previous ileocolic resection. In patients treated laparoscopically, oral alimentation, discontinuation of parenteral narcotics, and hospital discharge were possible at an average of 3.4, 4.2, and 6.5 days postsurgery, respectively. Patients operated upon using open techniques stayed in the hospital an average of 8.5 days. Laparoscopic-assisted intestinal resection is beneficial to selected patients with Crohn's disease. The presence of both a fixed mass and fistula on preoperative evaluation is predictive of conversion to open laparotomy and should be considered a relative contraindication. Patients with either a fixed mass or a fistula alone are more amenable to laparoscopic-assisted intestinal resection, while patients with primary uncomplicated Crohn's disease appear to be ideally suited to minimally invasive surgery.

Crohn Disease↗