What are the benefits and harms of different approaches to the treatment of screen-detected prostate cancer?
Active surveillance provides a balance of benefits and harms. After 15 years, for every 100 participants 40 can avoid the need for surgery with no increase in the risk of death, although 3 to 4 more develop metastatic disease than in the groups treated initially with surgery or radiation.(LOE = 1b)
Overuse alert: This POEM aligns with Choosing Wisely Canada's patient material on low-risk prostate cancer.
Randomized controlled trial (nonblinded)
The ProtecT Study is a clinical trial in the United Kingdom that, with its initial publication 5 years ago, provided the best information available on the benefits and harms of surgery, radiation, and active surveillance for men with screen-detected prostate cancer. Of 2664 men with localized prostate cancer detected by screening between 1999 and 2009, a remarkable 1643 agreed to be randomized to prostatectomy, radiotherapy, or active surveillance. With active surveillance, any patient or physician concern or an increase of at least 50% in prostate-specific antigen level prompted a review, further testing as appropriate, and consideration for therapy. This study reports the outcomes a median of 15 years following enrollment. The primary and secondary outcomes are reported per 1000 person-years, which is a bit hard to interpret clinically as few of my patients live that long. I reframe it as 100 patients followed for 10 years, or 67 patients followed for 15 years. The primary outcome of prostate cancer–specific mortality was uncommon with no significant difference among the groups, ranging from 1.5 to 2.2 deaths per 1000 person-years (or per 100 men followed for 10 years). There was also no significant difference in all-cause mortality. Metastatic disease was approximately twice as likely in the active surveillance group, with an excess of approximately 3.5 more diagnoses of metastatic disease per 1000 person-years. Patients receiving active surveillance were also more likely to start androgen-deprivation therapy (9.4 vs 5.3 to 5.6 per 1000 person-years) and more likely to experience any clinical progression, which included metastasis, progressing to T3 or T4, requiring androgen deprivation, or having anatomic complications due to tumor growth. By 15 years, the glass-half-full interpretation is that approximately 40% of men were able to avoid radiotherapy or surgery.
Mark H. Ebell, MD, MS
University of Georgia