Critical evaluation of the current indications for transition zone biopsies.

OBJECTIVES: Two primary indications for the performance of anteriorly directed transition zone (TZ) biopsies are (a) an elevated prostate-specific antigen (PSA) level and an enlarged, non-nodular prostate and (b) prior negative sextant biopsies of the prostate. These indications are, however, based on a study population evaluated early in the PSA era (1989 to 1992). The current analysis targeted a more contemporary series of patients (1995 to 2000) presenting with these two indications for TZ biopsies, who underwent ultrasound scanning and biopsies by the same examiner and with the same equipment as in the earlier series. METHODS: We evaluated 390 men, 274 (70.3%) of whom underwent sextant plus TZ biopsies for elevated PSA levels and an enlarged, non-nodular prostate; 116 (28.7%) underwent this biopsy strategy because of an elevated or rising PSA in whom prior sextant biopsies had not revealed cancer. RESULTS: Of the 274 patients who underwent initial sextant biopsies plus anterior biopsies for an enlarged, non-nodular prostate, 49 (17.9%) were found to have adenocarcinoma and in only 4 (1.5%) did only the TZ biopsies reveal cancer. Of the 116 patients who underwent TZ biopsies after prior negative sextant biopsies, 36 (31.0%) were found to have prostate cancer and in 11 (9.5%) only the TZ biopsies demonstrated cancer. CONCLUSIONS: The cancer detection rate for sextant plus TZ biopsies in this contemporary series of patients presenting with enlarged, non-nodular prostates was substantially lower than the rate in earlier reports (1.5% compared with 36.9%), despite the consistency in the equipment and examining physician. This may have been due to the stage migration of prostate cancer, which has been observed as a result of the widespread use of PSA measurement for early detection. Sextant plus TZ biopsies are more productive in patients with prior negative biopsies who have a persistent clinical suspicion for prostate cancer on the basis of an elevated and/or rising PSA level.

Effectiveness of denuding the intestinal mucosa by submucosal injection in the porcine model.

PURPOSE: Lack of mucosal regrowth on denuded bowel segments is considered a prerequisite for successful grafting of cultured urothelial cells for bladder augmentation. This study was designed to establish a technique for clean and complete de-epithelialization of the intestinal mucosa. MATERIALS AND METHODS: A segment of the small bowel was isolated in six microminipigs. The isolated segment was detubularized and the submucosa injected with HEPES-buffered saline, elevating the mucosa from the underlying tissue and allowing removal with ease. One portion was resected and, along with a portion of the removed mucosa and a sample of the full-thickness bowel, submitted for histologic evaluation. Another portion of the bowel segment remained denuded while the final denuded segment was covered with polyglactin mesh. After 3 days, 1 week, and 3 weeks, specimens from each of the bowel segments were collected for histologic assessment. Immunoperoxidase labeling was performed to confirm the presence or absence of mucosal regrowth. RESULTS: All intestinal segments showed no mucosal regrowth at the 3-day, 1-week, and 3-week incubation periods. Minimal reaction between the denuded bowel segment and the mesh was evident in all of the pigs. CONCLUSIONS: In the porcine model, intestinal mucosa can be removed completely using submucosal injection. This technique may be useful in future clinical studies involving bladder augmentation using denuded bowel.

Fluorodeoxyglucose positron emission tomography studies in diagnosis and staging of clinically organ-confined prostate cancer.

OBJECTIVES: To determine the value of 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) studies in the evaluation of patients with organ-confined prostate cancer. This imaging method has previously found little usefulness in localized prostate tumors because of excretion of the isotope into the urine, masking any lower urinary tract lesions. We evaluated this imaging modality using hydration, furosemide, and bladder emptying before the procedure to evacuate the nonspecific isotope in the urine. METHODS: FDG PET scans were performed on 24 patients diagnosed with clinically organ-confined prostate cancer. No patient had received any prior treatments for the cancer. FDG PET scans were performed 1 hour after injection of 15 mCi of F-18 deoxyglucose. Patients were scanned from the base of the skull through the inguinal region (including the pelvis). Additional signal attenuation-corrected images of the inguinal region were acquired 30 minutes after intravenous injection of 40 mg of furosemide. The final diagnosis was made by histologic examination, correlative imaging studies, and/or clinical follow-up. RESULTS: FDG PET studies were negative in 23 of the 24 organ-confined prostate cancers and the study was only faintly positive in 1 tumor (4.0% sensitivity). CONCLUSIONS: FDG PET is not a useful test in the evaluation of clinically organ-confined prostate cancer.

The significance of abnormally high and low maternal serum alpha-fetoprotein levels between 14 and 25 weeks of gestation.

A total of 6,160 gravidas with gestational ages from 14 to 25 weeks were collected to quantify maternal serum alpha-fetoprotein (MSAFP) using an enzyme immunoassay kit. A level over 2.5 MoM (multiples of the median) was defined as high and a level below 0.4 MoM as low. Ninety-eight women (1.59%) had an initially high MSAFP and 88 (1.42%) a low MSAFP. In the low MSAFP group, 80% returned for a further checkup. Among them, 46% had an over-estimation of gestational age based on their last menstrual period (LMP), 28% had a normal MSAFP and 9% still had a low MSAFP level on a repeat test. Pathologic conditions in other pregnancies included a hydatidiform mole, miscarriage and pseudocyesis. One nonresponder had an ectopic pregnancy. After delivery, no major fetal abnormalities, including trisomy syndromes, were noted in pregnancies carried to term. In the high MSAFP group, 84% returned for check-up. Among them, 15% had an under-estimation of gestational age based on LMP, 16% had twin pregnancies, 46% had a normal MSAFP and 12% still had a high MSAFP on a repeat test. Pathologic conditions in the other pregnancies included one anencephaly, one hydrocephaly and 6 miscarriages. Wrong dating by LMP and false positivity were the most frequent causes of abnormal levels of MSAFP. Two gravidas had artificial abortions because of undue anxiety. MSAFP screening in Taiwan for open neural tube defects does not seem appropriate and using 0.4 MoM as a fixed low cut-off point is inadequate for trisomy syndrome screening. Maternal anxiety should be seriously considered and proper genetic counseling implemented in a screening procedure.