Primary Prostate Cancer Management: The Difference at 5 Years

Abstract & Commentary

Synopsis: The Prostate Cancer Outcomes Study reports health-related quality-of-life findings 5 years after diagnosis on a cohort of prostate cancer patients who had either initial radical prostatectomy or external beam radiation therapy. Patients who were treated with radiation were more likely to experience rectal discomfort and hemorrhoidal pain, whereas those who were treated surgically suffered a somewhat greater rate of urinary incontinence. Sexual dysfunction, which was clearly more prominent for surgically treated patients at 2 years, was no different at 5 years.

Source: Potosky AL, et al. J Natl Cancer Inst. 2004;96:1358-1367.

The initial treatment for men with localized prostate cancer remains somewhat controversial with both radiotherapy and surgical options offering a chance for prolonged survival. Currently, the pattern of treatment often reflects local expertise, but to some extent, decisions are based upon the patient’s choice with regard to possible adverse outcomes of one approach vs the other. The adverse sequelae of radical prostatectomy or external beam radiation have recently been reviewed1,2 and include urinary, bowel and sexual dysfunction. The Prostate Cancer Outcomes Study (PCOS) was designed to prospectively assess the long-term health-related quality of life outcomes for a large, diverse, population-based sample of men treated in the community.3 Using the Surveillance, Epidemiology, and End Results (SEER) registries, 5672 men aged 39-89 with biopsy-proven primary invasive carcinoma of the prostate diagnosed over an approximate 1-year period (1994/95) were identified and 3533 (62%) participated by completing a 6- and 12-month survey. For the current report 2047 (of the original 3533 PCOS participants) were between the ages of 55-74 at the time of original diagnosis. The more narrow age range (55-74) was chosen because in this cohort, radiotherapy was uncommonly selected as initial treatment in men younger than 55 years (8%) and radical prostatectomy was infrequent among men older than 74 years (7%). Of the 2047 patients, 444 were excluded from this analysis because neither radiation nor radical prostatectomy was chosen. Other exclusions yielded a sample size of 1591 patients aged 55-74 years with clinically localized prostate cancer who received either external beam radiation or radical prostatectomy within one year of cancer diagnosis. These men were part of the cohort for whom quality-of-life data were reported at 2 years.4 The clinical and quality of life data collected at baseline and at 2 years was used as a part of the current analysis in comparison with the same information collected at 5 years. Particular attention was paid to issues that relate to urinary, bowel or sexual function.

At 5 years after diagnosis, overall sexual function declined in both groups approximately to the same level. However, erectile dysfunction was more prevalent in the surgery group (79.3% vs 63.5% in those receiving radiation). Furthermore, approximately 15% of the surgery patients compared to 4% of the radiation patients were incontinent at 5 years. Bowel urgency and painful hemorrhoids were more common in the radiation group. All of these differences remained statistically significant after adjustment for confounders and differences between the groups in some baseline characteristics.

Thus, after 5 years, men treated with radical prostatectomy for localized prostate cancer continue to experience worse urinary incontinence than men treated with external beam radiotherapy. However, the 2 treatment groups were more similar to each other with respect to overall sexual function, mostly because of a continuing decline in erectile function between years 2 and 5 after radiation treatment.

Comment by William B. Ershler, MD

The primary goal of treating localized prostate cancer is tumor eradication, and both external beam radiation and surgery have been of demonstrable success. Under such circumstances, quality-of-life issues concerns appropriately greatly influence patient decisions. The current report provides significant new data on a large cohort of patients. Although, observational, the numbers available for analysis allow confidence that any imbalance in treatment groups or other confounding factors would be satisfactorily controlled. Thus, after 5 years there remain differences with regard to urinary incontinence (somewhat worse after surgery) and rectal urgency and hemorrhoidal pain (somewhat worse after radiation). The new finding is that the advantage with regard to overall sexual function observed at 2 years in the radiation group, was all but gone by year 5. Thus, there remain some differences with regard to adverse sequelae after initial prostate cancer therapy for those with localized disease. Urinary and bowel problems persist, but the difference in sexual function diminishes. Eventually, new surgical or radiation techniques will tip the scales, but for the time being, the long term adverse consequences of primary treatment for localized prostate cancer remain quite comparable. Accordingly, the initial treatment decision remains a matter of local patterns of care and community expertise.

References

1. Eton DT, Lepore SJ. Psychooncology. 2001;10:1-20.

2. Penson DF, et al. J Urol. 2003;169:1653-1661.

3. Potosky AL, et al. J Natl Cancer Inst. 1999;91: 1719-1724.

4. Potosky AL, et al. J Natl Cancer Inst. 2000;92:24-34.

William B. Ershler, MD, INOVA Fairfax Hospital Cancer Center, Fairfax, VA; Director, Institute for Advanced Studies in Aging, Washington, D is Editor of Clinical Oncology Alert.