By: Dan Sperling, MD

Whole gland treatments for prostate cancer all have a risk of side effects. A very recent German study revealed what might be considered typical rates of incontinence and erectile dysfunction (ED) a year after radical prostatectomy (RP).[i] What sets it apart from similar reports is both the number of patients in the database (8,295) and the fact that the data is categorized by increasing age. Not surprisingly, the older patients had higher rates of side effects. It bears pointing out that for study purposes, continence was defined as “no more than one safety pad” per day, which is less strict than no pads at any time. Potency was defined as an international index of erectile function (IIEF)-5 score of 18 or higher. The following table summarizes the findings:

Incontinence and erectile dysfunction are the two side effects that most patients are aware of, and will take into consideration before choosing surgical prostate removal. There are less well known side effects, and these have been identified in a study last year out of Toronto (Sunnybrook Research Institute and University of Toronto) that analyzed treatment related problems for both RP and radiation therapy.[ii] This study involved 32,465 patients; 15,870 had RP, and 16,595 had radiation. The authors accumulated data on hospitalization to manage treatment-related problems, minimally invasive urological procedure, minimally-invasive rectal or anal procedures, open surgery to manage urologic, rectal or anal problems, or secondary malignancy (new cancer resulting from radiation exposure). The team found a 22.2% 5-year incidence of hospitalization, most of which was due to urinary obstruction. The 5-year rates (cumulative) of urinary obstruction were 13%, rectal/anal procedure 13.7%, open procedures 0.9% and secondary malignancy 3%. According to the study, surgery was associated with an increased number of minor urologic procedures, whereas radiation was associated with more hospital admissions, rectal/anal procedures, open surgical procedures, or secondary malignancies. It is important to be aware that most patients may be less well-informed of these treatment risks, and therefore less likely to ask their doctors about them before making a treatment decision.

One more study bears mention, because it specifically addresses late-onset side effects of brachytherapy, or permanent radioactive seed implants. Many patients who are facing a treatment choice are drawn to brachytherapy because it has a lower early side effect profile. However, as the paper out of UCLA by Kishan et al. shows, there is a chance of later rectal side effects even with low-dose brachytherapy.[iii] The risk of longer term damage showing up is something that many men do not take into account. In the case of seed implants, the authors point out, “A primary concern is late radiation proctitis, a clinical entity embodied by various signs and symptoms, ranging from diarrhea to rectal fistulas.” (Fistulas are holes in the rectal wall due to radiation damage that slowly builds up in the tissues.) After a thorough review of all published literature on late radiation proctitis after low-dose-rate brachytherapy, the authors report that the long-term chance of rectal bleeding averages 5-7%, but the risk of severe ulceration or fistula was less than 1%, depending on how much of the rectum was exposed to the prescription radiation dose. However, they note that certain cases will have an increased risk of rectal wall damage, up to 10-fold, if there is aggressive biopsy after brachytherapy, or the patient has increased sensitivity to radiation. While there exists a “variety of excellent management options” for rectal bleeding, men who are leaning toward brachytherapy are well-advised to discuss late onset proctitis with their doctor, and perhaps seek preliminary consultation from a urologist, as they are the specialists who often deal with the radiation damage years after an interventional radiologist has performed the treatment.

Newly diagnosed prostate cancer patients can be overwhelmed by the amount of information they encounter as they begin to ponder their options. It is important that they learn about less well-known risks of radical treatments such as surgery, beam radiation and seed implants, even if the odds are small, in order to make the most well-informed decision.

[i] Mandel P, Graefen M, Michl U et al. The effect of age on functional outcomes after radical prostatectomy. Urol Oncol. 2015 Mar 23. pii: S1078-1439(15)00048-4. doi: 10.1016/j.urolonc.2015.01.015. [Epub ahead of print]

[ii] Nam RK, Cheung P, Herschorn S et al. Incidence of complications other than urinary incontinence or erectile dysfunction after radical prostatectomy or radiotherapy for prostate cancer: a population-based cohort study. Lancet Oncol. 2014 Feb;15(2):223-31.

[iii] Kishan AU, Kupelian PA.  Late rectal toxicity after low-dose-rate brachytherapy: Incidence, predictors, and management of side effects.  Brachytherapy. 2015 March – April;14(2):148-159.