Hormonal therapy may be given for several months before radiotherapy to reduce the size of the prostate and make radiotherapy more effective. This is known as neo-adjuvant therapy. It can also be given during radiotherapy (concurrent). Hormonal therapy can be continued for several months, or even years, after radiotherapy (adjuvant therapy).
There is clear evidence that adjuvant hormone therapy provides benefits in patients with locally advanced disease. A number of clinical trials have now also shown that neoadjuvant hormone therapy can improve tumour control, and possibly survival, in men with locally advanced prostate cancer.(9),(12)
The Radiation Therapy Oncology Group (RTOG) 92-02 trial compared neoadjuvant hormone therapy with or without long term adjuvant hormonal therapy after radiotherapy in men with locally advanced prostate cancer. Men were either given long term adjuvant Zoladex or no subsequent treatment following neoadjuvant Zoladex/flutamide and radiotherapy.(13)
The results showed that in patients with Gleason scores 8 – 10 long term adjuvant androgen deprivation resulted in a survival advantage. Neoadjuvant therapy and radiotherapy may be more suited to men with Gleason scores under 8. And adding long term adjuvant therapy to this may be best reserved for men with PSA levels greater than 8.
The TROG 96.01 trial compared giving radiotherapy alone to radiotherapy with three or six months of androgen deprivation (Zoladex and flutamide) in patients with locally advanced prostate cancer. The results showed that six months of androgen deprivation given before and during radiotherapy improved outlook. Further follow up is needed to estimate precisely the size of survival benefits. It is suggested that increased radiation and additional periods of androgen deprivation might lead to further benefit.(14)
Non-steroidal anti-androgens offer potential quality of life benefits (sexual interest and bone density) over LHRH’s. The Early Prostate Cancer (EPC) programme is assessing bicalutamide (Casodex) 150mg in addition to standard care (radiotherapy, watchful waiting or radical prostatectomy). Analysis shows that bicalutamide 150 mg/day given as adjuvant to radiotherapy significantly improved progression-free survival in patients with locally advanced disease. The most common unwanted effects were breast pain and gynaecomastia which were mild to moderate in more than 90% of cases.(15)
New trials are looking at whether shorter durations of androgen deprivation can increase survival without harmful effects. Long term androgen deprivation is linked increased risk of fracture.