Biomedical subjects

Herbert A Fritsche

Publications and source records attributed to Herbert A Fritsche.

24 records · Page 2Linked to original sources

PubMed2002

Complexed prostate-specific antigen for early detection of prostate cancer in men with serum prostate-specific antigen levels of 2 to 4 nanograms per milliliter.

Complexed PSA (cPSA) has been shown to improve specificity in the detection of prostate cancer over that of total PSA (tPSA) testing in men with tPSA values greater than the cutoff value of 4.0 ng/mL. However, recent studies have reported a 25% incidence of prostate cancer in men with tPSA values in the 2.5- to 4.0-ng/mL range. We performed a multicenter study of cPSA in a population of men who underwent prostate biopsies because of elevated PSA levels or abnormal digital rectal examination (DRE). As part of this study, we sought to assess the clinical value of cPSA in comparison to tPSA, the free/tPSA ratio (f/tPSA) and the complexed/tPSA ratio (c/tPSA) in early detection of prostate cancer in men with tPSA values in the range of 2 to 4 ng/mL. The study was performed at 7 centers. Sera were drawn from men who underwent biopsy procedures consisting of >10 prostate tissue cores. Receiver operating characteristic (ROC) analysis was performed from the results of patients with tPSA values in the range of 2 to 4 ng/mL, including men with suspicious as well as unremarkable findings on DRE. Sera were collected and tested with the Bayer tPSA and cPSA assay and the Beckman free PSA and tPSA assays. ROC analysis was performed for all samples in the 2- to 4-ng/mL PSA range. At biopsy, 158 men had no evidence of malignancy and 57 (26.5%) were diagnosed with prostate cancer. ROC analysis indicated that the area under the curve (AUC) for cPSA was 0.64, which was statistically significantly greater than that achieved for tPSA (AUC, 0.57; P <0.0001). The AUC for f/tPSA and c/tPSA were 0.60 and 0.63, respectively, which was not statistically significantly different from that of tPSA or cPSA (P >or=0.252). A cutpoint of 2.5 ng/mL for tPSA and 2.1 ng/mL for cPSA provided a specificity of 20.3% and 34.2%, respectively, and sensitivity levels of 86%. Using cutpoints of 25% for f/tPSA and 74% for c/tPSA provided a specificity of 11.0% and 21.5%, respectively, and sensitivity levels of 97%. In all, >92% of the cancers treated with radical prostatectomy were organ confined, and the histologic grading of the tumors ranged from moderately to poorly differentiated with Gleason scores from 5 to 9. These data confirm that there is a high incidence of clinically significant prostate cancer in men with tPSA levels <4.0 ng/mL. Measurement of cPSA proved useful in stratifying men with tPSA values in the 2- to 4-ng/mL range into high- and low-risk groups for prostate cancer. The use of cPSA as a single test was found to enhance detection of prostate cancer over that of testing with tPSA and PSA ratios in men with tPSA values in the range of 2 to 4 ng/mL.

Adult↗

PubMed2002

Can volume measurement of the prostate enhance the performance of complexed prostate-specific antigen?

We assessed whether volume-based complexed prostate-specific antigen (cPSA) indices could enhance prostate cancer detection in men with serum total PSA (tPSA) between 2.5 and 10.0 ng/mL. Between December 1998 and April 2000, cPSA assay was measured in 480 men who underwent transrectal ultrasound-guided prostate biopsies at 7 institutions. We compared the usefulness of cPSA and its indices with the ratio of free PSA (fPSA) to tPSA (percent fPSA) for early detection of prostate cancer. Overall, 168 men (35%) had cancer. In the 341 men with tPSA between 4.01 and 10.0 ng/mL at approximately 90% sensitivity and areas under the receiver operating characteristics curve, the performances of volume-based parameters were significantly better (P <0.05) than those of tPSA and cPSA. In the 139 men with tPSA between 2.5 and 4.0 ng/mL, at 90% sensitivity, the specificity of the ratio of cPSA to tPSA (percent cPSA) was best, followed by cPSA density (cPSAD). In the 101 men with the history of a previous prostate biopsy, at approximately 90% sensitivity, the specificity of cPSAD was significantly better than those of tPSA and percent fPSA (P <0.05). In the 371 men with a total prostate volume of >or=30 cm(3) at approximately 90% sensitivity, the specificity of the cPSAD was significantly better than that of tPSA, percent fPSA, and cPSA (P <0.05). In the 109 men with a total prostate volume of <30 cm(3), at 90% sensitivity the specificity of cPSA and cPSAD was better than that of percent fPSA. In conclusion, volume-based cPSA can modestly enhance the performance of cPSA.

Humans↗

PubMed2002

Complexed prostate-specific antigen as a staging tool: results based on a multicenter prospective evaluation of complexed prostate-specific antigen in cancer diagnosis.

Within a 7-site prospective evaluation of the Bayer complexed prostate-specific antigen PSA (cPSA) assay, we analyzed the ability of cPSA to predict extracapsular extension (ECE) before radical prostatectomy. Included in this analysis were 152 men diagnosed with cancer, who subsequently underwent radical prostatectomy. Sera were tested with the Bayer total PSA (tPSA) and cPSA assays, and the Beckman free PSA (fPSA) and tPSA assays. Treating surgical pathology result as a binary variable (organ confined vs ECE), mean tPSA, cPSA, fPSA/tPSA (f/tPSA) ratios, tPSA density (tPSAD), and cPSA density (cPSAD) were compared by receiver operating characteristic (ROC) curves and univariate analysis. In all, 28 men (18.4%) had pathologically identified ECE. Between those with and without ECE, significant differences were observed for tPSA (P = 0.0127), cPSA (P = 0.0120), tPSAD (P = 0.0001), and cPSAD (P = 0.0002), but not f/tPSA (P = 0.3774) or c/tPSA (P = 0.2882). All tested parameters except f/tPSA (P = 0.376) and c/tPSA (P = 0.288) predicted ECE (P <0.05) by logistic regression. The ROC area under the curve (AUC) was identical for tPSA and cPSA (0.621) and for tPSAD (0.692) and cPSAD (0.691). Kendall-tau correlation coefficients also demonstrated the strongest correlation with ECE for cPSAD and tPSAD. Either alone or as a tPSAD calculation, cPSA carries equivalent staging ability to tPSA. The use of f/tPSA appears to be less effective in staging than either cPSA or tPSA, whereas the use of either cPSAD or tPSAD provides maximal staging accuracy. Therefore, cPSA could be applied as an accurate predictor of ECE independently or in a nomogram along with other predictive variables.

Aged↗

PubMed2002

Improving the yield of preoperative parathyroid localization: technetium Tc 99m-sestamibi imaging after thyroid suppression.

BACKGROUND: Preoperative localization is essential for successful directed, minimally invasive or reoperative parathyroidectomy. Standard technetium Tc 99m-sestamibi imaging is the most sensitive modality for localization. We reviewed our experience with (99m)Tc-sestamibi imaging and specifically investigated the effect of thyroid suppression on repeat imaging of patients who had initially nonlocalizing scans. METHODS: . The records of patients who underwent (99m)Tc-sestamibi imaging during evaluation for primary hyperparathyroidism were reviewed. A subset of patients with initially nonlocalizing scans underwent thyroid suppression with either thyroxin or liothyronine and then had their scans repeated. RESULTS: Ninety-nine patients with primary hyperparathyroidism underwent (99m)Tc-sestamibi imaging followed by parathyroidectomy (initial operation, 78; reoperation, 21). Successful parathyroid localization was obtained on standard imaging in 67 patients. Fourteen of 32 patients who had nonlocalizing (99m)Tc-sestamibi imaging studies underwent an additional scan after thyroid suppression. In 10 of 14 patients (71%), repeat (99m)Tc-sestamibi imaging after thyroid suppression successfully localized abnormal parathyroid tissue. CONCLUSIONS: Thyroid suppression may improve the yield of (99m)Tc-sestamibi imaging in patients with hyperparathyroidism who have an initially nonlocalizing study. This diagnostic strategy may be helpful in patients motivated to undergo a directed, minimally invasive operation, as well as in the evaluation of patients for reoperative parathyroidectomy.

Humans↗

PubMed2002

Phase II clinical trial of N-(4-Hydroxyphenyl)retinamide and tamoxifen administration before definitive surgery for breast neoplasia.

PURPOSE: Surrogate end point biomarkers (SEBs) that can be measured in ductal carcinoma in situ or early-stage invasive cancer are needed to improve the efficiency and reduce the cost of chemoprevention trials. EXPERIMENTAL DESIGN: We conducted a prospective study to develop SEBs for tamoxifen and N-[4-hydroxyphenyl]retinamide by administering either a placebo or both drugs for 2-4 weeks to women with ductal carcinoma in situ or early invasive cancers in the interval between the initial diagnostic core biopsy and definitive surgery. The major statistical end point of the study was pre- versus posttreatment change in cell proliferation, as measured by changes in Ki67 labeling indices. In addition, estrogen receptor (ER), HER2/neu, p53, retinoid receptors, and DNA index were measured. RESULTS: Between February 1997 and April 200, 52 patients were registered on the study, and 36 (20 in the placebo arm and 16 in the treatment arm) were available for analysis. No statistically significant pre- versus posttreatment differences in Ki67 labeling index or in the other markers were observed in the treatment arm compared with the placebo arm. There was a trend toward increased treatment response in ER-positive versus ER-negative patients, but this could not be rigorously analyzed because of the low sample size and the unequal distribution of ER-positive patients in the two study arms. CONCLUSION: Future SEB trials for breast carcinoma must (a) incorporate information about patient hormonal status into the study design and (b) resolve problems in patient accrual.

Adult↗

PubMedDate not supplied

Evaluation of precursor prostate-specific antigen isoform ratios in the detection of prostate cancer.

OBJECTIVE: Disease-associated isoforms of the prostate-specific antigen (PSA) have recently been identified. We evaluated the efficacy of using precursor isoforms of PSA (pPSA) and their ratios for the detection of prostate cancer. METHODS: Serum concentrations of [-2], [-4], and [-7]pPSA, BPSA, and free PSA (fPSA) were retrospectively measured in 43 selected men. Of the 43 men, 15 had clinical T2 prostate cancer with ultrasound-estimated prostate volumes (PVs) of >50 cm(3), 13 had clinical T2 prostate cancer with (PVs) <25 cm(3), and 15 were prostate cancer-free with PV >50 cm(3). We calculated sum pPSA ([-2]+[-4]+[-7]pPSA). We also compared the ratios of: free/total PSA, [-2]pPSA/fPSA, [-2]pPSA/BPSA, [-2]pPSA/(fPSA-BPSA), [-2]pPSA/(fPSA-sum pPSA), and [-2]pPSA/{fPSA-(sum pPSA+BPSA)} among these three groups. RESULTS: The median [-2]pPSA/(fPSA-sum pPSA) ratio was significantly higher in men with prostate cancer with or without large PV compared with men with large PV without prostate cancer. Values for median [-2]pPSA/free PSA ratio were higher in men with prostate cancer with or without large PV compared with men with large PV, and without prostate cancer, but the differences were not statistically significant. CONCLUSIONS: In this preliminary study, [-2]pPSA/(fPSA-sum pPSA) ratio was not associated with prostate gland volume but was associated with prostate cancer. This ratio may be useful in the detection of prostate cancer, particularly in men with larger glands.

Adenocarcinoma↗