PSA response to secondary androgen deprivation following failed treatment of metastatic prostate cancer with the antiandrogen casodex

Rising prostate-specific antigen after primary treatment of prostate cancer: sequential hormone manipulation

OBJECTIVE

To evaluate systematically the current endocrine treatment options for patients with biochemical recurrence after radical prostatectomy or radiation therapy for localized prostate cancer.

METHODS

Literature search of PubMed documented publications and abstracts from international meetings. Key items included timing and type of salvage hormone therapy, length of its application and handling of side effects.

RESULTS

The majority of patients with isolated prostate-specific antigen (PSA) relapse are not candidates for salvage treatment with curative intent. The PSA threshold that triggers initiation of hormonal therapy is debatable and should be based also on pretreatment risk assessment. Intermittent androgen suppression is an emerging concept to circumvent the unresolved controversy of early versus deferred endocrine therapy. Since the tumor load at time of recurrence is low, peripheral androgen blockade with an antiandrogen and a 5alpha-reductase inhibitor is an acceptable first choice. In case of progression, addition of a LHRH analogue would be the next step. Antiandrogen withdrawal and second-line antiandrogens are clinically of limited value.

CONCLUSIONS

Biochemical-only progression after definitive treatment in curative intent is different from objective or even symptomatic relapse and allows for sequential hormonal therapy with a variety of compounds.

An update on bicalutamide in the treatment of prostate cancer

In this update, bicalutamide (Casodex, Zeneca Pharmaceuticals) has been confirmed as an effective, well-tolerated and convenient non-steroidal anti-androgen for advanced prostate cancer. Preclinical and clinical studies have indicated its potential as monotherapy, with quality of life advantages compared with castration. A head-to-head comparison with flutamide, where both anti-androgens were used as part of combined androgen blockade, has suggested that the choice of components in this regimen can influence outcome, and has demonstrated that bicalutamide is better tolerated than flutamide. There is also preliminary evidence to support the potential use of bicalutamide in treatment of early-stage disease and tumours that are refractory to other non-steroidal anti-androgens.

An evaluation of bicalutamide in the treatment of prostate cancer

Although prostate cancer is traditionally considered a disease of old age, improved diagnostic techniques have resulted in early diagnosis, and many men are now treated while still physically and sexually active. Current therapies for prostate cancer often include medical or surgical castration, which cause adverse effects on physical and sexual function; therefore, greater attention has been focused on quality of life. The nonsteroidal antiandrogen bicalutamide is an effective agent with a favorable tolerability profile and, in some settings, represents an alternative to castration. Mature survival data reveal that bicalutamide monotherapy provides survival benefits for untreated locally advanced disease that do not differ significantly from those of castration and maintains better physical capacity and sexual interest. Recent data from a prospective randomized trial demonstrate that bicalutamide given as immediate therapy, either alone or as adjuvant to therapy of curative intent, significantly reduces the risk of objective disease progression in patients with localized or locally advanced prostate cancer. Antiandrogens are also used in combination with castration, a treatment known as combined androgen blockade (CAB), for advanced disease. A randomized trial demonstrated that CAB with bicalutamide is associated with similar survival outcome to CAB with flutamide and is better tolerated. Current evidence demonstrates that bicalutamide currently has a favorable risk-benefit ratio in several stages of prostate cancer and that the role of bicalutamide will be further defined by ongoing studies.

An evaluation of bicalutamide in the treatment of prostate cancer

Prostate cancer is a major health problem in men, causing significant morbidity and mortality. Although traditionally considered a disease of old age, improved diagnostic techniques have resulted in earlier diagnosis and many men are now treated while still physically and sexually active. Current therapies for prostate cancer, which include medical or surgical castration, have a significant impact on many aspects of quality of life. The non-steroidal antiandrogen bicalutamide (Casodex, AstraZeneca) has a favourable tolerability profile with demonstrated efficacy in several stages of prostate cancer and represents an alternative therapeutic strategy to castration. Mature survival data from men with previously untreated, locally-advanced disease reveal that bicalutamide monotherapy provides survival benefits that do not differ significantly from castration, while offering important advantages with respect to the maintenance of physical capacity and sexual interest. Recent data from a prospective randomised trial, the largest prostate cancer treatment study ever conducted, demonstrate that immediate therapy with bicalutamide (alone or as an adjuvant to therapy of curative intent) significantly reduces the risk of objective disease progression in patients with localised or locally-advanced prostate cancer. Antiandrogens are also used in combination with castration (combined androgen blockade) for advanced disease. Another large, randomised trial demonstrated that combined androgen blockade with bicalutamide is associated with a similar survival outcome to combined androgen blockade with flutamide and is better tolerated. The evidence reviewed demonstrates that bicalutamide currently has a favourable risk:benefit ratio in several stages of prostate cancer. The role of bicalutamide will be further defined by ongoing studies.