Combination of hormone therapy and radiation reduces mortality from prostate cancer
Hormone and radiation therapy in locally advanced prostate cancer
16 December 2008 Umeå …
In patients with locally advanced prostate cancer, radiotherapy can significantly improve the results of endocrine (anti-hormonal) therapy. This is shown by a randomised trial in the Lancet (Doi: 10.1016/S0140-6736(08)61815-2).
Until now, locally advanced prostate carcinoma was usually treated exclusively with anti-hormonal therapy (“3-month injections”). A combination of radiation therapy and hormone therapy is standard for a curative goal in localised prostate cancer.
In a randomised study, the Scandinavian Prostate Cancer Group has now investigated anti-hormonal therapy and external radiotherapy for locally advanced prostate cancer with a non-curative goal.
The SPCG-7/SFUO3 study involved 875 men (mean age: 66 years) with locally advanced prostate cancer (T3N0M0). Half of the patients received combined androgen blockade for three months. This was followed by monotherapy with flutamide. In the other half of the patients, this endocrine therapy was combined with external radiation (50 grays to the prostate and seminal vesicle, plus 20 grays to the prostate).
After an average of 7.6 years, 79 of 439 patients in the endocrine-only group died of prostate cancer, compared to 37 of 436 in the combination therapy group. Anders Widmark from the University of Umeå and colleagues calculate a cancer-specific 10-year survival rate of 23.9 percent with the combination versus 11.9 percent with endocrine therapy alone. The prostate cancer-specific risk of death could thus be more than halved (relative risk 0.44; 95 percent confidence interval 0.30-0.66).
In terms of overall survival, the combination was also advantageous, even if the difference here was not as clear: the additional radiotherapy increased the 10-year survival rate from 29.6 to 39.4 percent. The authors therefore consider the combination to be the standard therapy for advanced prostate carcinoma. Editorialist Chris Parker of the Institute of Cancer Research in Sutton agrees, even though the endocrine therapy chosen at the time does not correspond to today’s standard and the authors may have judged the toxicity of radiotherapy (in the non-blinded study) somewhat too favourably (Lancet 2008; doi: 10.1016/S0140-6736(08)61816-4). The increase in patients with urinary or bowel problems or sexual dysfunction was small in the study.