Local Control After Radiation for Prostatic Carcinoma: Significance and Assessment

Local tumor control is of great importance in the definitive treatment of prostatic carcinoma. Not only is it the best measure of radiation efficacy but its significance in terms of the related morbidity and mortality of tumor recurrence has been clearly shown. On this we would all likely agree. More controversial, however, is the definition of local failure and the manner in which this determination is made. Having until recently largely referred clinical findings by rectal exam, prostate-specific antigen (PSA), ultrasound, and biopsy findings have, of late, presented additional information. Whether data from these evaluations should expand our current definition of local failure is as yet undecided. Surely their predictive value is less disputable. Of prime consideration is the practicality of therapeutic options for disease recurrence. By virtue of their age and initial tumor stage, the majority of patients with local failure after irradiation, including chemical (PSA) and microscopic (positive biopsy) failure, are unlikely to be good surgical candidates. Thus, salvage surgery, like repeat irradiation has questionable benefit and a relatively high risk of significant complications. Although hormonal therapy is fairly innocuous, there is no evidence as yet that treating subclinical disease is advantageous. Therefore, with this particular malignancy that affects men who often die of competing causes with incidental microscopic cancer totally undiagnosed, a pragmatist might prefer to think in terms of clinical cure. However, that is not to say that we will give up our continuing efforts toward improving radiation efficacy and enhancing the therapeutic ratio.