Focal or subtotal therapy for early stage prostate cancer

Abstract

Focal treatment for prostate cancer is highly intriguing, but poorly supported by the published literature. Further studies, preferably randomized controlled trials, are needed before this can be considered standard therapy. Focal treatment should be reserved for patients with focal disease. Even "clinically insignificant" synchronous tumors are malignant, and carry risk of progression if not treated with the index lesion. Whether these are likely to progress in this setting compared to those managed with active surveillance is unknown. The limited data regarding subtotal or focal cryotherapy suggest that patients properly evaluated for presence of satellite tumors have a low risk of having large unknown satellite tumors. The author requires office-based saturation biopsy prior to considering focal cryotherapy. Observation of prostatic intraepithelial neoplasia (PIN), atypical findings (ASAP), or cancer on the contralateral biopsy cores excludes the patient from consideration of subtotal therapy. MRI offers a potential additional ability to detect occult contralateral tumors. Younger men paradoxically seem to have greater interest in focal therapy while having a higher risk of future malignancy in the untreated areas based on the years of potential risk. However, no age cutoff is established. Without published data to support its use, lumpectomy or freezing only the focus where cancer is believed to exist, will remain limited. Hemispheric or subtotal treatment decreases the amount of untreated tissue. As a result, the local failure rate would be predicted to be lower but is unknown. When performing subtotal treatment, the author freezes almost the entire gland, sparing only the aspect adjacent to the contralateral neurovascular bundle, and has found this practice to be of highly limited utility based on the issues described. Biopsy should be performed following any treatment that fails to target the entire gland. A positive biopsy should be dealt with based on clinical factors as if the patient had not been treated, and a positive biopsy should not preclude active surveillance if deemed appropriate.