FAQS about Focal Therapy for Prostate Cancer
Frequently asked questions about focal therapy for prostate cancer.
- What is focal therapy? Is it feasible?
- How does the Smilow Center select candidates for focal therapy?
- What is the preferred energy source for focal therapy?
- How do we decrease the risk of progression of residual disease after focal therapy?
- What is the follow-up after focal therapy?
What is focal therapy? Is it feasible for prostate cancer?
Men who have prostate cancer confined to one small area of the prostate may wish to consider focal therapy (also known as partial gland therapy or prostate ‘lumpectomy’). The goal of focal therapy is to ablate only the small area of the prostate that is cancerous, rather than removing or ablating the entire gland. The rationale for focal therapy is based on the observation that low-risk prostate cancer is sometimes ‘over-treated’, in the sense that some of these cancers are unlikely to cause harm. In these cases, a less invasive procedure will cause fewer unnecessary complications. There are, however, many small cancers that threaten the well-being of younger men. The aim of focal therapy is to destroy all of the biologically active cancer while reducing the risk of side effects that are associated with removal or destruction of the entire prostate gland.
Today, focal therapy is feasible. Smilow Center surgeons have taken the lead in defining the role of focal therapy in the treatment of prostate cancer. (Taneja SS, Tareen B. Cancer 113(7):1500-1 (2008); Tareen B, Godoy G, Taneja SS, Rev. Urol., in press). Research studies reported by the Smilow Center suggest that up to 25% of men who are diagnosed with low-risk, early, low-volume prostate cancer have their cancer confined to only one side of the prostate gland (Tareen B, Godoy G, Sankin A, Temkin S, Lepor H, Taneja SS. Urol. 73(2):351-4 (2009)). The challenge is to accurately identify these men, so as not to undertreat the cancer. Smilow physicians are aggressively pursuing biopsy and imaging methods to meet this challenge (Tareen B, Godoy G, Sankin A, Temkin S, Lepor H, Taneja SS. BJU Intl. 104(2):195-9 (2009); Taneja SS, Tareen B. Cancer 113(7):1500-1 (2008)).
At present, Smilow Center surgeons believe that focal therapy should be offered only to men with low-risk prostate cancers. Smilow Center investigators have demonstrated that the risk features of a cancer are more predictive of disease outcome than the presence of multifocal (multiple-location) cancers (Tareen B, Godoy G, Sankin A, Temkin S, Lepor H and Taneja SS. J. Urol. 181(3):1082-9 (2009)). Men who have low-risk, regionally confined prostate cancer may consider focal therapy as an alternative to active surveillance as a strategy to minimize any possibility of treatment-related side effects (Dhar N et al. J. Urol. 181(4):715 (2009)).
How does the Smilow Center select candidates for focal therapy?
Advanced mapping biopsy and MRI techniques employed by Smilow Center surgeons allow accurate assessment of the true extent and location of the cancerous regions of the prostate and help to determine if focal treatment is possible. Smilow Center surgeons are actively involved in the research and development of new biopsy techniques using computer-guided robotics, MRI, and advanced ultrasound imaging, including Doppler and HistoScan technology. Smilow Center doctors believe that accurate selection of candidates for focal therapy can and will be conducted by a combination of transrectal biopsy and imaging (Taneja SS. Rev. Urol. 8:173-182 (2006); Tareen B, Godoy G, Sankin A, Temkin S, Lepor H, Taneja SS. BJU Intl. 104(2):195-9 (2009); Taneja SS, Tareen B. Cancer 113(7):1500-1 (2008); Rosenkrantz AB, Neil J, Kong X, Melamed J, Babb JS, Taneja S, Taouli B. Amer. J. Roentgenol., in press).
What is the preferred energy source for focal therapy?
Focal treatment for prostate cancer can be accomplished using cryotherapy, HIFU, lasers or photodynamic approaches. There are robust clinical data for cryotherapy and HIFU, whereas lasers and photodynamic therapy are truly investigational. Both cryotherapy and HIFU give the surgeon the ability to target specific regions of the prostate for treatment. Cryotherapy is approved for use in the United States, and Smilow Center surgeons have over a decade of experience with focal cryotherapy. HIFU is a new technology that has been used in Europe for focal therapy. Although not yet approved by the US FDA for the treatment of prostate cancer, Smilow Center surgeons offer focal HIFU in offshore treatment centers in Nassau, Bahamas and Cancun, Mexico. There are no studies that compare focal cryotherapy to focal HIFU, but Smilow Center surgeons believe that HIFU is more precise and non-invasive and may offer advantages over cryotherapy because of these factors.
How do we decrease the risk of progression of residual disease after focal therapy?
Because focal therapy only treats a part of the prostate, normal, noncancerous prostate tissue is left untreated. There is also a high possibility of microscopic sites of prostate cancer cells remaining in the untreated prostate tissue. The Prostate Cancer Prevention Trial showed that finasteride, a drug commonly used to treat BPH, was able to reduce the risk of prostate cancer development by 25% (Thompson IM et al. N. Engl. J. Med. 2004; 350:2239-2246).
Smilow Center surgeons advocate the use of medications such as finasteride and dutasteride to reduce the risk of prostate cancer developing or progressing in the untreated prostate tissue. A Smilow Center physician has been involved in the design and execution of a national clinical trial evaluating the use of dutasteride in men with low-risk prostate cancer on active surveillance (Fleshner N, Gomella LG, Cookson MS, Finelli A, Evans A, Taneja SS et al. Prostate Cancer Prostatic Dis. 11(1):46-52 (2008)). If the trial demonstrates an effect, this will provide a strong rationale for the use of dutasteride in patients undergoing prostate cancer focal therapy. Smilow Center surgeons also endorse the use of complementary herbal supplements and nutriceuticals to promote prostate health. The Smilow Center team includes a naturopathic physician specializing in prostate cancer.
What is the follow-up after focal therapy treatment for prostate cancer?
As with all treatments for prostate cancer, close monitoring is required after focal therapy. In particular, PSA monitoring is essential. Advanced imaging techniques such as MRI and Doppler ultrasound may also be useful to monitor both the treated and untreated regions of the prostate for recurrence. If PSA rises after focal therapy, a targeted biopsy is required to differentiate residual healthy prostate tissue from prostate cancer recurrence. If there is recurrence of cancer or development of cancer in previously benign regions of the prostate, then repeat focal therapy or total gland therapy may be recommended, depending on the location and extent of the recurrent cancer.