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Biomedical subjects

H B Carter

Publications and source records attributed to H B Carter.

At least 55 records · Page 3Linked to original sources
PubMed1996

Multicenter comparison of the diagnostic performance of free prostate-specific antigen.

OBJECTIVES: This study examined the multicenter clinical performance of noncomplexed (free) prostate-specific antigen (PSA) in men presenting with total PSA values between 2.5 to 20 ng/mL. METHODS: Prebiopsy serum samples were obtained from 1,081 consecutively accrued, histologically diagnosed men between the ages of 40 and 75 years with total PSA values falling between 2.5 and 20 ng/mL. Total PSA was determined by either the Tosoh AIA-1200 or Hybritech method. Free PSA values were determined using the Dianon PSA II immunoradiometric method. Free PSA was expressed as a percentage of total PSA. Immunochemistry was performed at each accrual site. RESULTS: Among men diagnosed with prostate cancer (CaP), only 4% (21/520) had proportions of free to total PSA values > 25%. Conversely, among men with benign prostatic disease, only 2% (13/561) had proportions of free to total PSA values < 7%. These results confirm those of previous research. Differences among sites were found in age and prostate volume. CONCLUSIONS: These data confirm that free PSA values < 7% are highly suspicious for CaP whereas free PSA values > 25% suggest absence of malignancy. The data also suggest that age and/or prostate volume influences the serum level of free PSA but does not affect the diagnostic cutoff points of 7% and 25%. Future analysis is needed to confirm that younger men with small prostates are at higher risk for CaP.

Adult↗
PubMed1996

The role of free/total prostate-specific antigen ratio in the prediction of final pathologic stage for men with clinically localized prostate cancer.

OBJECTIVES: The combined use of total prostate-specific antigen (PSA), clinical stage, and Gleason score accurately predicts final pathologic stage for men with clinically localized prostate cancer. Recently, the free/ total PSA ratio has been proposed as an adjunct for early detection of prostate cancer. We examined the association between free/total PSA and pathologic stage. METHODS: In a prospective study, 301 consecutive men with clinically localized prostate cancer (average age 58.8 years, range 45-72) underwent a staging pelvic lymphadenectomy and radical prostatectomy. Total PSA and free PSA were measured from preoperative sera. Pathologic stage was determined as organ-confined (OC, n = 169), capsular penetration (CP+, n = 108), seminal vesicle involvement (SV+, n = 13) and lymph node involvement (LN+, n = 11). RESULTS: Overall, 292/301 (97%) of the free/total PSA values were < 25%, and thus suspicious for prostate cancer. Combination of total PSA, Gleason score, and clinical stage predicted well OC (P = 0.00001) and LN+ (P = 0.023); whereas, replacing total PSA with free/total PSA ratio did not improve the prediction of OC (P = 0.0007) nor LN+ (P = 0.03). CONCLUSIONS: The free/total PSA ratio cutoff point of 25% had high sensitivity for prostate cancer among a group of men with clinically localized disease. The free/total PSA ratio did not significantly improve the prediction of pathologic stage provided by total PSA when used alone or in combination with Gleason score and clinical stage. These preliminary data demonstrate that free/total PSA levels provide no additional information for pathologic stage prediction when combined with Gleason score and clinical stage in men with clinically localized prostate cancer.

Aged↗
PubMed1996

The use of prostate-specific antigen and free/total prostate-specific antigen in the diagnosis of localized prostate cancer.

Although there is controversy regarding the benefit of early detection of prostate cancer, it has been demonstrated that early detection can be best achieved through the use of a combination of digital rectal examination and prostate-specific antigen (PSA). This article outlines the clinical use of PSA for early detection of prostate cancer and focuses primarily on the value of molecular forms of PSA (free PSA, complexed PSA, and total PSA) in the diagnosis of localized prostate cancer.

Age Factors↗
PubMed1996

Ureteral frozen section analysis during cystectomy: a reassessment.

PURPOSE: Frozen section analysis of the distal ureteral margins is commonly performed at cystectomy to exclude involvement of tumor in retained ureter. We reviewed our experience with 101 consecutive cystectomies to determine the contemporary incidence and clinical significance of the urothelial abnormalities detected by frozen section analysis performed at operation. METHODS AND MATERIALS: The pathology reports for 101 patients treated with nerve sparing cystectomy between 1982 and 1989 were reviewed. Frozen section and final ureteral analyses were compared. RESULTS: Of the patients 8% had evidence of a urothelial abnormality ranging from mild atypia to frank carcinoma in situ involving the distal ureters on frozen section. Only 4 patients had documented carcinoma in situ at the final margin and all 4 ultimately died of disease. The frozen section false-positive and false-negative rates were 2 and 6%, respectively. In 6 patients with ureteral urothelial abnormalities documented on frozen section ureterointestinal anastomosis was performed despite persistent abnormalities at the ureteral margins, frequently after multiple frozen analyses failed to clear the margins definitively. None of the 6 patients in this group experienced upper tract recurrence during a mean followup of 41 months. CONCLUSIONS: These data suggest that routine frozen section analysis of the ureteral margins at cystectomy may not be necessary for most patinets undergoing cystectomy.

Adult↗
PubMed1996

Clearance rate of serum-free and total PSA following radical retropubic prostatectomy.

BACKGROUND: Our objective was to determine the clearance rate of free and total serum PSA following radical retropubic prostatectomy. METHODS: Sera were obtained from 10 men with localized prostate cancer prior to and 1, 4, 8, 24, 48, and 72 hr after radical prostatectomy. No patient received any postoperative blood transfusion. Free and total PSA were measured using the Hybritech Tandem-R (total PSA) and radioimmunometric free PSA assay. Postsurgery serum-free and total PSA concentrations were modeled using a "two-compartment" pharmacokinetic model. RESULTS: The pharmacokinetic model with an initial constant "infusion" suggests that, following release from the prostate, both free and total PSA are taken up into a second compartment for metabolism. The movement of PSA between these compartments was accurately modeled. Following surgery, there is a shift of both free and total PSA best modeled as a constant infusion into the serum at a rate of 1.97 and 1.60 ng/ml, respectively, for a period of approximately 1 hr. Following this initial constant infusion, the half-life estimations for free and total PSA are initially 1.2 and 0.75 hr, respectively, which then increase to 22 and 33 hr, respectively. CONCLUSIONS: Serum free and total PSA are cleared from the circulation following a "two-compartment" model with an initial constant "infusion." The constant "infusion" is most likely a consequence of surgical manipulation. The initial half-life estimates are < 2 hr for both free and total PSA, and later increase to 22 and 33 hr, respectively.

Aged↗
PubMed1995

Longitudinal evaluation of serum androgen levels in men with and without prostate cancer.

Androgens are thought to play a role in the pathogenesis of prostate cancer. We evaluated androgen levels in 3 age-matched groups of men who were part of the Baltimore Longitudinal Study of Aging: 1) 16 men with no prostatic disease by urologic history and exam (control group); 2) 20 men with a histologic diagnosis of benign prostatic hyperplasia (BPH) who had undergone simple prostatectomy; and 3) 20 men with a histologic diagnosis of prostate cancer (16 with local/regional cancer, and 4 with metastatic cancer). Luteinizing hormone (LH), total testosterone (T), and free T were measured on stored AM sera by radioimmunoassay (RIA). Free T was also calculated from the measured concentrations of total T and sex hormone binding globulin (SHBG). The median number of repeated sex steroid measurements ranged from 6-9 over a period from 7-25 years prior to the diagnosis of prostate disease. There were no significant differences in age-adjusted LH, total T, SHBG, or calculated free T levels among the groups at 0-5, 5-10, and 10-15 years before diagnosis. These data suggest that there are no measurable differences in serum testosterone levels among men who are destined to develop prostate cancer and those without the disease.

Age Factors↗
PubMed1995

Serum ferritin as a clinical marker for renal cell carcinoma: influence of tumor volume.

OBJECTIVES: At present, 35% to 50% of patients with clinically localized renal cell carcinoma (RCC) unpredictably have a recurrence after surgical therapy. Presently, no clinical serum marker exists to detect occult metastases and to allow measurement of response to therapy in RCC. Serum ferritin was previously reported to correlate with pathologic stage. We postulated that this increase in serum ferritin with increasing stage might reflect tumor volume, since higher stage tumors are often larger. METHODS: Serum ferritin levels were measured preoperatively in 30 patients with radiologic evidence of RCC. Tumor volume and the largest tumor dimension were calculated from either the pathologic specimen (n = 24) or from the computed tomography or magnetic resonance imaging (n = 30). Pathologic stage was determined for all patients undergoing surgery (T1 = 3, T2 = 12, and T3 = 9). RESULTS: Preoperative serum ferritin levels did not correlate with age, blood urea nitrogen levels, creatinine levels, hematocrit, race, or gender. Although mean serum ferritin levels increased with increasing stage (T1 = 113 +/- 75, T2 = 254 +/- 270, and T3 = 425 +/- 257 ng/mL), these differences did not reach statistical significance (P > 0.05). Serum ferritin did, however, correlate with tumor volume (R = 0.75; P < 0.0001) and the largest tumor dimension measured from radiographic studies (R = 0.8; P < 0.0001). Serum ferritin measured intraoperatively from the renal vein (666 ng/mL) and the inferior vena cava (564 ng/mL) from a patient with a 500 cc tumor (preoperative serum ferritin, 552 ng/mL) suggested that the tumor was the source of the elevated ferritin levels. Histologic sections from tumors taken from patients with high serum ferritin levels were more necrotic and stained intensely positively for iron and immunohistochemically for ferritin, whereas adjacent histologically normal tissue did not. CONCLUSIONS: These data suggest that ferritin may be a useful serum marker for monitoring patients with RCC, but the actual source of the ferritin remains unclear and dictates further investigation.

Adult↗
PubMed1995

Prostate-specific antigen variability in men without prostate cancer: effect of sampling interval on prostate-specific antigen velocity.

OBJECTIVES: To evaluate short-term and long-term variability between prostate-specific antigen (PSA) measurements to determine the most appropriate PSA sampling interval and rate of PSA change (PSA velocity) to distinguish between men with and without prostate cancer. METHODS: Retrospective study of PSA variability and PSA velocity in three groups of men without a diagnosis of prostate cancer and PSA levels less than 10 ng/mL: 56 men with a histologic diagnosis of benign prostatic hyperplasia (BPH; histologic BPH group) and 527 men with no history of cancer (noncancer group) who were part of the Baltimore Longitudinal Study of Aging and had PSA sampled at 2-year intervals (long-term), and 223 men with a clinical diagnosis of BPH (clinical BPH group) who had PSA sampled at 3-month intervals (short-term). PSA variability (deviation between consecutive measurements) and PSA velocity based on both two consecutive measurements and three consecutive measurements (average velocity) were calculated for each study group. RESULTS: PSA velocity is the deviation in PSA measurements relative to the elapsed time between the measurements. Because the variability in PSA between measurements was similar for the groups, the major factors that influenced PSA velocity were the sampling interval between PSA measurements, and to a lesser extent, the number of repeat PSA measurements. The 99th percentile for PSA velocity was 0.7 (histologic BPH group) and 0.75 ng/mL per year for the noncancer group when three measurements with a 24-month PSA sampling interval were used. However, the 99th percentile for PSA velocity was 5.8 and 2.4 ng/mL per year when three measurements with 3-month and 6-month PSA sampling intervals were used. Using three measurements, the percentage of subjects with a PSA velocity more than 0.75 ng/mL per year was 1% for the groups with a 24-month PSA sampling interval and 28% and 17% for 3-month and 6-month PSA sampling intervals, respectively. The 99th percentile for PSA velocity and the percentage of subjects with a PSA velocity more than 0.75 ng/mL per year was higher using two measurements compared to three measurements regardless of PSA sampling interval. CONCLUSIONS: PSA velocity is inversely related to the interval between PSA measurements. A PSA velocity more than 0.75 ng/mL per year is useful in distinguishing between men with and without prostate cancer when: (1) velocity is based on three consecutive measurements; and (2) PSA is sampled long-term (2 years) but not short-term (3 to 6 months).

Aged↗
PubMed1995

Relationship between changes in prostate-specific antigen and the percent of prostatic epithelium in men with benign prostatic hyperplasia.

OBJECTIVES: Pretreatment knowledge of prostate gland histology would allow a more scientifically based selection of medical therapy for men with benign prostatic hyperplasia (BPH) and may increase the effectiveness of the pharmacologic agents available. Changes in prostate-specific antigen (PSA), or PSA velocity, may reflect prostatic epithelial growth in BPH. Our objective was to determine if PSA velocity prior to diagnosis correlated with the relative amount of epithelium in BPH tissue. METHODS: We evaluated 39 men with BPH who had serial PSA determinations (mean, 5.4) on frozen sera from 2.3 to 25.1 years before diagnosis, and archival material from simple prostatectomy available for pathologic evaluation. We used an immunoenzymatic staining technique for PSA to bind prostatic epithelium selectively so that color differences in the stained tissue sections could be used to quantify stroma, epithelium, and glandular lumina. RESULTS: The average percentage of epithelium (%E) was 12.4 and the average stroma-epithelial ratio (SER) was 6.6. The correlation of PSA velocity for the three visits nearest to prostatectomy (n = 32) versus %E and SER was significant (P = 0.003 for both). The PSA value nearest to prostatectomy (n = 39) was directly correlated with %E and SER (P = 0.0001 and P = 0.001, respectively). CONCLUSIONS: These data suggest that PSA and PSA velocity are directly related to the histologic makeup of the prostate in men with BPH. Thus, pretreatment evaluation of PSA could be useful as part of an evaluation to direct BPH therapy.

Aged↗
PubMed1994

Evaluation of serum prostate-specific antigen velocity after radical prostatectomy to distinguish local recurrence from distant metastases.

OBJECTIVE: Serum prostate-specific antigen (PSA) values are most useful for prediction of disease recurrence after surgery. It is unknown whether a detectable PSA level after surgery indicates a local recurrence potentially benefiting from pelvic irradiation or distant metastases requiring hormonal treatment. METHODS: We analyzed postoperative rate of change of serum PSA levels as a predictor of local versus distant disease recurrence after radical prostatectomy. Between 1982 and 1991, 1,058 men underwent radical prostatectomy for localized prostate cancer and follow-up consisted of determining serum PSA levels and digital rectal examinations. Clinical follow-up of 542 men for four or more years and 78 men for eight or more years yielded ten-year actuarial disease recurrence rates of 4 percent for local recurrence, 8 percent for distant metastases, and 23 percent for an isolated elevation of serum PSA level only. Fifty-one patients with isolated elevations of PSA levels only were followed expectantly until they were diagnosed with either local or distant metastases. RESULTS: A linear mixed effects regression analysis was used to model these data. Using these models, the time to a serum PSA level of 0.5 ng/mL, the PSA level one year following surgery, pathologic stage, Gleason sum, and the rate of change of PSA (PSA velocity [PSAV]) were tested as predictors of local versus distant metastases. A combination of PSAV, pathologic stage, and Gleason grade best distinguished local from distant metastases. CONCLUSIONS: These data suggest that PSAV in men with an isolated elevation of PSA levels following radical prostatectomy might aid in clinical decision making.

Actuarial Analysis↗
PubMed1994

Natural history of changes in prostate specific antigen in early stage prostate cancer.

Until recently, the only information on the growth rate of prostate tumors has been derived from cross-sectional histological labeling studies, autopsy data and clinical studies of patients managed expectantly. However, serial measurements of prostate specific antigen (PSA) may now allow studies of the natural history of the earliest stages of prostate cancer. Frozen sera samples from the Baltimore Longitudinal Study of Aging have been used to compare the patterns of change in PSA levels in men with and without prostate cancer up to 25 years before the diagnosis of cancer. Men with no prostatic disease exhibited a slow linear increase in PSA levels, whereas benign prostatic hyperplasia cases showed a gradual acceleration in the rate of change in PSA. In contrast, cancer cases exhibited an early linear phase followed by an exponential phase of increase in PSA levels before diagnosis. On average, the exponential phase of PSA increases began 7 to 9 years before the tumors were detected clinically. Thus, there is a significant window of opportunity for early detection of prostate cancer. The changes in PSA observed in men with and without prostate cancer are consistent with available information on prostatic growth and the long natural history of prostate cancer. A better understanding of the various factors that affect serum PSA levels may allow more effective use of PSA measurements to detect early stage tumors and predict the biological potential of a tumor.

Adult↗
PubMed1993

Relationship between changes in prostate-specific antigen and prognosis of prostate cancer.

Changes in prostate-specific antigen (PSA), used to estimate PSA doubling times, may reflect prostate cancer growth. To determine if PSA doubling time prior to diagnosis predicted outcome in men with prostate cancer, we evaluated 16 men with prostate cancer who had (1) serial PSA determinations (mean 9.9) on frozen sera from twelve to twenty-six years before diagnosis; (2) at least five years of follow-up in those subjects without metastatic disease (range 5.5-12.3 years); and (3) archival material from diagnosis available for pathologic evaluation. PSA doubling time prior to diagnosis was investigated with relation to patient outcome (regardless of treatment) and the known predictors of tumor behavior, Gleason score and nuclear morphometry. In 5 of 16 men who had evidence of metastatic disease at diagnosis, metastasis developed or they died of prostate cancer during follow-up (group 1). Eleven of 16 had no evidence of metastatic disease during follow-up (group 2). Both Gleason score and variance of nuclear roundness (VNR) were significantly greater for group 1 (p < 0.05). There was no significant difference between the two groups with respect to PSA doubling time, and the PSA level at diagnosis did not correlate with the development of metastatic disease. One of 5 men with no PSA level greater than 4.0 ng/mL prior to diagnosis died within two years of diagnosis. These data suggest that (1) a normal PSA at diagnosis does not exclude an aggressive cancer, and (2) changes in PSA that occur before the diagnosis of prostate cancer may not always predict outcome. Since PSA level is influenced by tumor grade, an inability to correct PSA for tumor grade could have influenced the results.

Aged↗
PubMed1993

The use of prostate specific antigen, clinical stage and Gleason score to predict pathological stage in men with localized prostate cancer.

Clinical stage, Gleason score and serum prostate specific antigen (PSA) levels are used separately to predict pathological stage in patients with localized prostate cancer. Because the degree of tumor differentiation has a profound influence on the expression of serum PSA, serum PSA levels alone do not reflect tumor burden accurately. To overcome this obstacle we tested these 3 variables alone and in combinations as predictors of final pathological stage in 703 men with clinically localized prostate cancer at our institution. All patients were assigned a clinical stage by 1 urologist. The Gleason score was determined from preoperative needle biopsy and serum PSA levels were measured on an ambulatory basis. Final pathological stage was determined to be either organ confined, established capsular penetration, seminal vesicle involvement or lymph node involvement. Logistic regression analysis with the likelihood ratio chi-square test determined that serum PSA, Gleason score and clinical stage all predicted final pathological stage well. The results were improved with combinations of the 3 variables (serum PSA, Gleason score and clinical stage) and the combination provided the best separation. From these analyses probability plots and nomograms have been constructed to assist urologists in the preoperative prediction of final pathological stage for patients with clinically localized prostate cancer.

Biomarkers, Tumor↗
PubMed1993

Does high grade prostatic intraepithelial neoplasia result in elevated serum prostate specific antigen levels?

Prior studies have evaluated high grade prostatic intraepithelial neoplasia on biopsy material when undiagnosed carcinoma or benign prostatic hyperplasia (BPH) may have been associated with elevated serum prostate specific antigen (PSA) levels. We studied 65 totally embedded radical prostatectomy specimens with minimal carcinoma (tumor volume 0.5 cc or less) and relatively minimal BPH (gland weight less than 65 gm.). Even for these relatively small glands, PSA showed a significant correlation with gland volume (r = 0.64). To account for BPH, PSA density (PSA divided by gland volume) was also calculated. In these specimens with trivial tumor the tumor volume did not correlate with PSA (r = 0.12) or PSA density (r = 0.23). The volume of high grade prostatic intraepithelial neoplasia also showed no correlation with PSA (r = 0.16) or PSA density (r = 0.14). The 11 cases with extensive high grade prostatic intraepithelial neoplasia (0.50 cc or more) had PSA density values of 0.03 to 0.14, with 10 less than 0.1. Of the 6 cases with PSA density values of 0.1 or more only 1 had a high grade prostatic intraepithelial neoplasia volume of 0.5 cc or more. These results indicate that high grade prostatic intraepithelial neoplasia in and of itself does not account for elevated serum PSA levels. In a patient with high grade prostatic intraepithelial neoplasia on biopsy material and elevated serum PSA values, BPH may account for the elevated serum PSA levels. More likely, because of the association between high grade prostatic intraepithelial neoplasia and carcinoma these patients have undiagnosed carcinoma as the source of the elevated serum PSA values.

Humans↗
PubMed1993

Tubularized neourethra following radical retropubic prostatectomy.

A 1.5 cm. tubularized neourethra was formed using an anterior bladder flap as part of bladder neck reconstruction after radical retropubic prostatectomy in 69 consecutive patients with clinically localized prostate cancer (study group). Postoperative continence (defined as requiring no protection for any activity) was assessed by history at 3 months (all men) and 6 months (45 of 69 men). Continence in the study group was compared to that of 45 men with 6 months of followup who underwent radical retropubic prostatectomy without tubularization of the anterior bladder (control group). At 3 months 38 of 69 men (55%) were continent in the study group and 14 of 45 (31%) were continent in the control group (p < 0.03). At 6 months 39 of 45 men (87%) were continent in the study group compared to 21 of 45 (47%) in the control group (p < 0.01). Upright cystograms performed on men with and without the tubularized neourethra after radical retropubic prostatectomy suggest that a neourethra proximal to the external sphincter may increase resistance in this area and result in early return of urinary control in men undergoing radical retropubic prostatectomy.

Aged↗