Update of hormonal treatment in cancer of the prostate

Estrogen and Risk of Gastric Cancer: A Protective Effect in a Nationwide Cohort Study of Patients with Prostate Cancer in Sweden

Background: The global pattern of male predominance in gastric cancer incidence remains unexplained. We tested the hypothesis that estrogen prevents gastric cancer in a cohort of men heavily exposed to estrogen.

Methods: We conducted a nationwide cohort study of men with a diagnosis of prostate cancer recorded in the Swedish Cancer Register in 1961-2000. Because estrogen therapy was the treatment of choice for prostate cancer in Sweden between 1950 and 1980, cohort members diagnosed earlier than 1980 were considered exposed to estrogen. Standardized incidence ratios (SIR) estimated relative risk. Complete follow-up was achieved through cross-linkages within the cancer register and the Swedish nationwide registers of emigration and causes of death.

Results: In 515,961 person-years of follow-up, we observed 304 gastric cancers as compared with 349 expected for the cohort members in the predefined “exposed” period 1961-1980, rendering a 13% decreased risk (SIR, 0.87; 95% confidence interval (95% CI), 0.78-0.98). Among patients with a latency of ≥15 years after a prostate cancer diagnosis in 1961-1980, SIR was 0.57 (95% CI, 0.30-0.97), suggesting a dose-response relation. Similarly, reduced risks were found for cardia cancer and noncardia gastric cancer. No decreased risk was found for the cohort members in 1981-2000, when estrogen treatment was less common (SIR, 0.99; 95% CI, 0.89-1.11).

Conclusions: Our study indicates a reduced risk of gastric cancer in a male cohort exposed to estrogen. These results support the hypothesis that estrogen may prevent gastric cancer, but additional studies are warranted.

Effects of long-term treatment with the anti-androgen bicalutamide on human testis: an ultrastructural and morphometric study

AIMS

To assess the effects of more than 4 years' treatment with the anti-androgen bicalutamide on human testis by clinical, ultrastructural and morphometric analysis.

METHODS AND RESULTS

Two patients (aged 74 and 69 years) with prostate cancer were treated for more than 4 years with bicalutamide 50 mg daily. Clinical characterization and follow-up included luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone and prostate-specific antigen (PSA) measurements and clinical response of the tumours. Due to progression of the disease, patients underwent surgical orchidectomy as a further androgen withdrawal therapy. Testis biopsies were studied by light and electron microscopy and analysed by morphometry. Control samples were obtained from the normal testis of two patients with testicular cancer who underwent orchidectomy. Clinical follow-up showed a good response in the control of tumour growth and serum PSA decreased to < 4 ng/mL; concentrations of serum LH, FSH and testosterone were within the normal range. Testicular morphology of treated patients was unexpectedly well preserved; the organization of seminiferous tubules was normal with all the germ line elements and mature spermatozoa present. In some areas, a net increase of peritubular connective tissue was evident which may be a consequence of the age of the patients.

CONCLUSIONS

Long-term bicalutamide (50 mg) treatment appears to have very little impact on testis ultrastructure and sperm maturation, while it is effective in the control of androgen-dependent prostatic tumours.

Controversies in the management of advanced prostate cancer

For advanced prostate cancer, the main hormone treatment against which other treatments are assessed is surgical castration. It is simple, safe and effective, however it is not acceptable to all patients. Medical castration by means of luteinizing hormone-releasing hormone (LH-RH) analogues such as goserelin acetate provides an alternative to surgical castration. Diethylstilboestrol, previously the only non-surgical alternative to orchidectomy, is no longer routinely used. Castration reduces serum testosterone by around 90%, but does not affect androgen biosynthesis in the adrenal glands. Addition of an anti-androgen to medical or surgical castration blocks the effect of remaining testosterone on prostate cells and is termed combined androgen blockade (CAB). CAB has now been compared with castration alone (medical and surgical) in numerous clinical trials. Some trials show advantage of CAB over castration, whereas others report no significant difference. The author favours the view that CAB has an advantage over castration. No study has reported that CAB is less effective than castration. Of the anti-androgens which are available for use in CAB, bicalutamide may be associated with a lower incidence of side-effects compared with the other non-steroidal anti-androgens and, in common with nilutamide, has the advantage of once-daily dosing. Only one study has compared anti-androgens within CAB: bicalutamide plus LH-RH analogue and flutamide plus LH-RH analogue. At 160-week follow-up, the groups were equivalent in terms of survival and time to progression. However, bicalutamide caused significantly less diarrhoea than flutamide. Withdrawal and intermittent therapy with anti-androgens extend the range of treatment options.

Androgen deprivation for prostatic carcinoma: a rationale for choosing components

Ever since prostatic carcinoma was discovered to be dependent on the hormone androgen for its proliferation, androgen deprivation has been the treatment of choice for advanced cases of prostate cancer. Originally, treatment was limited to surgical castration or estrogen therapy. However, the introduction of luteinizing hormone-releasing hormone analogues, antiandrogens, and newer treatment modalities, such as combined androgen blockade, has made choosing a treatment strategy more complex. Assuming that each modality is equally effective, emphasis should be placed on increasing patient tolerance and compliance by the use of long-acting, nontoxic treatments with simple dosing regimens and minimal side effects. This review focuses on the factors influencing the final choice of treatment strategy.

Androgen deprivation therapy for asymptomatic advanced prostate cancer in the prostate specific antigen era: a national survey of urologist beliefs and practices

PURPOSE

The use of androgen deprivation for prostate cancer without symptomatic metastases to the skeleton is controversial. However, by 1995 the use of medical androgen deprivation by injection was the thirteenth largest category of physician reimbursement by Medicare. To what degree do urologist attitudes towards androgen deprivation account for this growth?

MATERIALS AND METHODS

A survey was mailed to 582 United States urologists practicing at least 20 hours per week in 1995 which asked about use of androgen deprivation therapy when prostate specific antigen (PSA) levels rise after primary therapy (surgery or radiation). They were also asked whether they believed androgen deprivation provided a survival benefit for patients with asymptomatic stages C and D disease.

RESULTS

The response rate was 68%. Of the respondents 68% reported that they recommend androgen deprivation at least half of the time for men whose PSA is newly or persistently elevated following radical prostatectomy. Most (81%) urologists who believe that androgen deprivation offers a survival benefit for stage C disease said they prescribed it but more than half (53%) who do not believe in the efficacy of this treatment also said they still prescribe it.

CONCLUSIONS

Many urologists maintain an inclination to prescribe androgen deprivation for a rising or elevated PSA despite the absence of information about the benefit of this approach and their own conflicting beliefs.

Long-term efficacy and safety of nilutamide plus castration in advanced prostate cancer, and the significance of early prostate specific antigen normalization. International Anandron Study Group

PURPOSE

We studied the long-term efficacy and tolerability of nilutamide, a nonsteroidal antiandrogen, combined with orchiectomy in patients with advanced prostate cancer.

MATERIALS AND METHODS

A large double-blind trial was done on 457 patients randomized to receive nilutamide or placebo after orchiectomy.

RESULTS

At 8.5 years of followup significant benefits were found for progression and survival in favor of patients receiving nilutamide and orchiectomy. In addition, normalized prostate specific antigen levels at 3 months from the start of therapy were predictive of good long-term outcome. Moreover, combined androgen blockade with nilutamide increased the chance of patients having normal prostate specific antigen levels at 3 months. Nilutamide was well tolerated in the long term with no increase in the incidence of drug specific adverse events.

CONCLUSIONS

With long-term followup of patients with advanced prostate cancer, the combination of nilutamide and orchiectomy has significant benefits in interval to progression and improved survival compared to orchiectomy and placebo.