If a man’s prostate cancer comes back (or recurs), the treatment options available to him will depend significantly upon how his cancer was first treated and where the recurrent cancer is detected.

After a Radical Prostatectomy
If, after surgery, cancer recurs only in the prostate bed, in other words, if there is no distant cancer but only a local recurrence, it is still sometimes possible to cure the disease through radiation therapy. Radiation therapy given at this point is called salvage radiation or salvage radiotherapy. It appears to be most effective when given at the earliest sign of recurrence, and the usual method of delivery is external beam radiation.

If the recurrence is a distant metastasis, for example, to the bone, hormone therapy is a common treatment. Why? Doctors now need a whole-body or system-wide way of combating the cancer rather than a localized one, and hormone therapy is the best option in these circumstances.

Sometimes, hormone therapy and salvage radiotherapy will be combined, in an effort to combat the cancer on two fronts: the radiation to fight it locally and the hormone therapy to work against as yet undetected metastases. This combined treatment came about because research findings suggest that an early addition of hormonal therapy to whatever local therapy is given may increase life expectancy significantly.

Active surveillance is another possible option. If the recurrent cancer appears to be localized, slow growing, and not particularly risky in other ways, e.g., not in a very threatening spot in the body, your doctor might recommend a wait-and-see approach.

After Radiation Therapy or Brachytherapy
If, after radiation therapy or brachytherapy, a man’s prostate-specific antigen (PSA) level rises by 2 points or more or if a digital rectal exam has a positive result, it is likely that the cancer is coming back.  Again, it is important to determine where the recurrent cancer is and if it has spread or is confined to the prostate. To make these determinations, doctors will biopsy the prostate area and order a bone scan; often, a CT scan or MRI of the abdomen and pelvis will also be ordered.

If there is no sign that the cancer has spread, a local treatment might be suggested. These include HIFU (high-intensity focused ultrasound), cryotherapy, and surgery. Men should note, however, that HIFU and cryotherapy are relatively new and experimental options for the treatment of recurrent prostate cancer, so their long-term effectiveness as second-line therapies after the failure of external beam radiation or brachytherapy is unknown.

HIFU, a technique that uses heat to destroy the area of the prostate with cancer by means of a probe that gives out a beam of high-intensity focused ultrasound, is usually not appropriate after brachytherapy because doctors have found that there is a higher risk of patients developing a fistula (an opening between the urinary system and the bowel) with this as a secondary treatment. Indeed, HIFU as a salvage treatment for local recurrence after external beam radiation is rarely offered in Canada, as it is available only in experimental settings and there is insufficient evidence to recommend it. Ontario Cancer Care reported in 2009 that only five studies, none of them randomized clinical trials, had investigated the outcomes of HIFU as a salvage therapy. The largest study, which also had the longest follow-up (18.1 months), reported a negative biopsy rate of 73 per cent and a five-year disease-free survival rate of 17 per cent.  In 2011, a multicentre clinical trail testing HIFU as a treatment of locally recurrent prostate cancer was recruiting; Canadian institutions involved included the Manitoba Prostate Centre in Winnipeg and the London Health Services Centre in London, Ontario. (Click here to read about this clinical trial.)

Cryotherapy (the use of extreme cold to freeze and destroy cancer cells) has more evidentiary support. The UK’s National Institute for Health and Clinical Excellence issued provisional recommendations in 2005on salvage cryotherapy for recurrent prostate cancer: “Current evidence on the safety and efficacy of salvage cryotherapy for recurrent prostate cancer appears adequate to support the use of this procedure.” And the American Urological Association concluded in 2008 that evidence supports the consideration of cryotherapy in men in whom radiation therapy has failed, particularly when these men have “clinically localized disease and a PSA level of less than 10 ng/mL.”  In 2011, researchers from the London Health Sciences Centre in Ontario concluded that “cryotherapy has a definite role in the management of prostate cancer, representing a minimally invasive salvage treatment with an acceptable ten-year disease free survival  (DFS) of upward of 39 per cent, with specific groups attaining a ten-year DFS of 64 per cent.” Men should remember, however, that these new treatment options for recurrent prostate cancer after radiation therapy are currently being studied to see how effective and safe they are in the long term.

Even surgery as a salvage treatment (salvage radical prostatectomy), which has been used for longer as a second-line local cure, carries risks and may not be recommended. First, because the tissue of the prostate and surrounding area has been damaged by radiation, a surgeon may have difficulty seeing and cutting out all the areas that need to be removed. It may also be hard to avoid doing further damage to the bladder, urethra, rectum, and erectile nerves. Generally, there are more pronounced side effects, including impotence and incontinence, when surgery is used as a second-line rather than a primary treatment for prostate cancer. In some cases, a surgeon must cancel a salvage radical prostatectomy after making an incision and seeing the state of the tissue.

For all of these reasons, hormone therapy is the standard treatment for prostate cancer that recurs after radiation therapy or brachytherapy.

References:
David S. Finley and Arie S. Belldegrun, 2011, Salvage Cryotherapy for Radiation-Recurrent Prostate Cancer, Current Urology Reports, vol. 12, no. 3, 209-215.

J. Stephen Jones, Radiorecurrent Prostate Cancer: An Emerging and Largely Mismanaged Epidemic, European Urology, vol. 60, no. 3, 411-412.

A. R. Patel and A. J. Stephenson, 2011, Radiation Therapy for Prostate Cancer After Prostatectomy: Adjuvant or Salvage? Nature Reviews Urology, vol. 8, no. 7, 385-392.

M. Warmuth, T. Johansson, and P. Mad, 2010, Systematic review of the efficacy and safety of high-intensity focused ultrasound for the primary and salvage treatment of prostate cancer, European Urology, vol. 58, no. 6, 803-815.

A. K. Williams, C. H. Martinez, C. Lu, C. K. Ng, S. E. Pautier, J. L. Chin, 2011, Disease-free survival following salvage cryotherapy for biopsy-proven radio-recurrent prostate cancer, European Urology, vol. 6, no. 3, 405-410.