Molecular urology最新文献

Purpose: To determine whether nephron-sparing surgery is appropriate for patients with renal cell carcinoma (RCC) and a normal contralateral kidney.

Materials and methods: We prepared whole-area histologic sections from 58 cases of RCC to examine the features of satellite tumor lesions (STLs), the proliferative potential of which was evaluated by counting argyrophilic nucleolar organizing regions (AgNORs).

Results: We found three types of microscopic lesions: STLs, adenomas, and dysplastic foci, the latter two of which appeared to be preneoplastic. Of the 58 cases, STLs were observed in 27 (47%) and either adenomas or dysplastic foci in 19 (33%). At least one of the three types of lesion was found in 37 cases (64%). No correlation was found between the incidence of STL and the size of the main tumor, but the incidence tended to be higher in lesions of higher grade or stage. The STLs were located >2 cm from the margin of the main tumor in 6 of the 27 cases (22%). The mean number of AgNORs per high-power field was 5.09 +/- 1.53 (SD) in the main tumors, 4.21 +/- 1.36 in the STLs, and 2.27 +/- 0.07 in the adenomas and dysplastic foci.

Conclusions: These findings suggest that nephron-sparing surgery risks leaving STLs, which have considerable proliferative potential. Thus, nephron-sparing surgery must still be considered adventurous treatment in elective cases but can be recommended for patients who require nephron preservation.

Background and purpose: In order to evaluate the effect of short-term androgen blockade on biochemical control rates for high-risk patients receiving a combination regimen of external-beam radiation therapy and low-dose-rate permanent seed implant brachytherapy, a retrospective matched subset analysis was performed.

Patients and methods: Inclusion in the high-risk cohort required at least two of the following poor prognostic factors: serum prostate specific antigen (PSA) concentration > or = 10.0 ng/mL, Gleason score > or = 7, or clinical stage T(2c) or T(3a) disease. Twenty-one patients who underwent androgen ablation between June 1991 and December 1995 in addition to combined-modality radiation therapy qualified as high risk, as did 77 patients who underwent combined-radiation therapy only. There was no statistically significant difference between the two groups in terms of follow-up (mean 44.6 v 47.8 months, respectively), pretreatment PSA, clinical stage, biopsy Gleason score, or the presence of all three poor prognostic factors.

Results: The overall rates of freedom from biochemical failure at 5 years were 77% in the hormonally treated group and 58% in the nonhormonally treated group. The difference was not statistically significant by log rank test (P = 0.08).

Conclusion: Longer follow-up with larger patient numbers is needed to define the role of adjuvant androgen ablation combined with radiation therapy.

The Canadian Prospective Trial of intermittent androgen suppression was a prototype therapeutic initiative started in 1995 for the management of patients in biochemical relapse after radiation for localized prostate cancer. An interim analysis has yielded several observations on the relations between baseline serum prostate specific antigen (PSA), nadir serum PSA, Gleason score, and time off-treatment. In a typical androgen-dependent tumor, the response of serum PSA to androgen withdrawal is biphasic, but with early tumor progression, plateauing of serum PSA is observed. Ligand-independent activation of the androgen receptor, a mechanism subserving the initiation of androgen independence, can be counteracted experimentally with decoy molecules and clinically with nonsteroidal antiandrogens. In some patients, it is possible to lengthen the off-treatment interval by inhibiting the enzyme 5 alpha-reductase, an effect that can be reinforced by lowering serum testosterone with an antigonadotropin. Serial measurements of serum PSA indicate that intermittent androgen suppression engenders a more diverse range of hormone-related responses than previously appreciated. These include: (1) repeated differentiation of tumor with recovery of apoptotic potential; (2) inhibition of tumor growth by rapid restoration of serum testosterone; and (3) restraint of tumor growth by subnormal levels of serum testosterone. These responses are aspects of regulation that should be taken into account when planning long-term treatment of prostate cancer with intermittent androgen suppression.

Neoadjuvant androgen suppression (NAS) can reduce the number of tumor clonogens prior to radiation, thus increasing the tumor control probability. Also, NAS may sensitize tumor cells to radiation if cell kill by both modalities follows a common pathway. The timing and sequence of NAS and radiation are important, with radiation being most effective if given at the point of maximal tumor regression. The biologic rationale for NAS + radiation has been reinforced by results from randomized trials, in particular RTOG 8610. However, many murine adenocarcinomas respond to androgen deprivation by a reduction in the proliferation rate and arrest in G(0), and in vitro data suggest that this arrest may interfere with radiation-induced cell killing. The mechanism of cell killing after low-dose-rate radiation (brachytherapy) may be different from that after high-dose-rate treatment. There are no reported experimental data assessing the interaction of NAS and brachytherapy to determine whether the combination offers a theoretical advantage or is potentially deleterious. Whether we understand the mechanism or not, clinical trials seem to support a positive interaction of NAS with external-beam radiation, but we have only begun to explore the timing and sequence that will provide the maximal effect. It cannot be assumed that the same advantage will hold with brachytherapy.

Purpose: We performed a randomized trial to compare the efficacy and toxicity of a new dose of flutamide (500 mg QD) with the currently recommended dose (250 mg q8h) in the treatment of advanced prostate cancer. The primary endpoints were percent of patients having normalization of prostate specific antigen (PSA), time to normalization, and percent change from baseline. Secondary endpoints were quality of life and toxicity.

Patients: Altogether, 440 men aged 46 to 94 years (mean 71 years) with confirmed stage M(1) disease, documented PSA rise >0.2 ng/mL, ECOG status 0 to 2, no second neoplasm, no liver function tests > or = 1.5-fold normal values, and no previous treatment for metastatic disease were entered in the trial.

Results: The PSA normalized by week 12 in 71% of the patients receiving 500-mg dose and 75% of those receiving the standard dose. The percent change in PSA was 89% and 96%, respectively. The treatment groups were not significantly different with respect to the incidence of adverse events: 71% v 68% in the 500-mg and 250-mg arms, respectively (P = 0.337).

Conclusions: When combined with castration, 500 mg of flutamide appears to be equally effective in lowering serum PSA and is not significantly more toxic than conventional dosing. The use of 500 mg QD instead of the standard 250 mg q8h would result in a cost savings of 30%.