Orchidectomy prior to definitive radiotherapy for localized prostatic cancer

Long-term effects of intermittent androgen suppression on testosterone recovery and bone mineral density: results of a 33-month observational study

OBJECTIVE

To investigate changes in bone mineral density (BMD) and osteoporosis, over 3 years of intermittent androgen-suppression therapy (IAST).

PATIENTS AND METHODS

This was a Phase II individual cohort study of 72 patients with prostate cancer without metastatic bone disease, enrolled between 1999 and 2002. Patients had 9 months flutamide (250 mg, three times daily) and leuprolide (22.5 mg, 3-monthly depot) after which, patients ceased therapy providing that their PSA levels were <4 ng/mL. AST re-commenced when the PSA level exceeded the pretreatment level or was >20 ng/mL. BMD for hip and spine was the primary endpoint; assessed at baseline; completion of initial treatment period; and at 1 and 2 years after initial treatment (POST period).

RESULTS

Osteoporosis increased from 7% at baseline to 10% at 3 years. The BMD declined after 9 months treatment, at -1.9% and -3.3% at hip and spine, respectively (P < 0.001). Subsequent BMD decline in the POST period was attenuated; at 1 years and 2 years later, hip -0.6% (not significant), and -0.8% (P < 0.014), and spine +1.0% and +0.2% (not significant). The BMD change in those remaining 'off' therapy for 2 years (n = 20) was strongly associated with the level of testosterone recovery; a peak testosterone level of <5 nmol/L associated with a greater then normal physiological loss. Testosterone recovery was less likely in older men.

CONCLUSION

The attenuation of spine and hip BMD decline after 3-year IAST compared with those reported for continuous AST appears to be due to testosterone driven BMD recovery in the POST period. Failure of testosterone recovery was associated with worse final BMD. By reducing the potential risk for adverse bone complications, intermittent therapy may become an important consideration when the therapeutic ratio is narrow.

Use of neoadjuvant and adjuvant therapy to prevent or delay recurrence of prostate cancer in patients undergoing radiation treatment for prostate cancer

Multiple oncologic treatment modalities are often integrated into the curative treatment approach for the patient with a newly established diagnosis of cancer. The combination of neoadjuvant and adjuvant therapies with radiotherapy for the care of the patient with prostate cancer is no exception. There is clear evidence that neoadjuvant androgen suppression reduces the volume of tumor in preparation for radiotherapy, and it is an effective addition to conventional-dose external radiotherapy in patients with large-volume primary prostatic tumors. Adjuvant androgen suppression improves local and systemic tumor control and improves survival duration compared with radiotherapy alone for patients with locally advanced or node-positive prostate cancer, particularly in those with high-grade disease. The role of neoadjuvant and adjuvant therapies is under intense scrutiny as several randomized clinical trials seek to optimize the combination of androgen suppression, chemotherapy, and radiotherapy. The historical precedent for combining androgen suppression with radiotherapy is described, as are the results of prior definitive trials and ongoing studies in this setting.

The role of androgen deprivation in the definitive management of clinically localized prostate cancer treated with radiation therapy

PURPOSE

Multiple studies exploring the use of androgen deprivation given in combination with radiotherapy (RT) for localized prostate cancer have reported significant improvements in the rates of local, regional, and biochemical control (BC). The impact of this therapeutic strategy on overall and cancer specific survival (CSS) has not been established, however. We performed a MEDLINE search of all available studies on this topic to determine if any conclusions could be reached on the efficacy of this treatment approach and the patients most suitable for its application.

MATERIALS AND METHODS

A MEDLINE search was conducted to obtain all articles in the English language on the use of androgen deprivation in combination with RT for the treatment of localized prostate cancer. The medical subject headings (MeSH) used to search the MEDLINE database included: a) prostatic neoplasms; b) prostatic neoplasms/radiotherapy; c) prostatic neoplasms/androgen deprivation; d) hormone therapy; e) English; and f) 1980 to 1998.

RESULTS

A total of 14 retrospective studies were identified that compared some form of androgen deprivation given in combination with RT. Most studies showed significant improvements in various measures of local/regional control and disease-free survival (DFS). Three of four studies that analyzed BC rates showed significant improvements in this endpoint but conflicting results were obtained for overall survival (OS). No study showed an improvement in CSS. Six prospective randomized trials were identified that directly compared RT with or without androgen deprivation. Again, all six studies showed improvements in some measure of local/regional control or DFS but only two studies showed an improvement in OS. One study reported a statistically significant improvement in CSS and another study showed an improvement in the rate of negative biopsies with combined treatment.

CONCLUSIONS

When all available literature on androgen withdrawal given in combination with RT for the definitive treatment of localized prostate cancer was reviewed, no definite conclusions could be reached on the impact of this treatment approach on OS and CSS. However, local/regional control, DFS, and BC were almost uniformly improved with the use of androgen withdrawal suggesting that these impressive early results may translate into improved cure rates. Data from recently initiated and completed randomized trials will be needed, however, to define the impact of this approach on cancer specific mortality and the patients most suitable for it's use.