By: Dan Sperling, MD
Active surveillance (AS) as a clinical strategy for patients diagnosed with early stage, low-risk prostate cancer has gained traction among both physicians and patients. As the term suggests, AS relies on patient compliance with monitoring at specified intervals. This may consist of testing for biomarkers (e.g. PSA, free PSA, genomic testing), repeat biopsy (TRUS or MRI-guided targeted), imaging (multiparametric MRI or mpMRI), or a combination of these. In fact, mpMRI plays a growing role in helping to determine whether a repeat biopsy is warranted[i], thereby removing the risks of side effect as well as patient anxiety over the biopsy procedure.
While AS permits a patient to defer treatment, consensus is lacking on
- Factors that qualify a patient for AS, and
- Triggers for further intervention (treatment).
A large Canadian study showed that patients who remain on long-term (15 years) AS do not have a significantly greater chance of mortality from prostate cancer than low-risk patients who receive definitive treatment upon diagnosis.[ii] However, roughly half of patients come off of AS within five years or less.[iii] Among the variables that determine when a patient comes off of AS are disease reclassification to a greater risk level, and patient discomfort with the idea of cancer possibly progressing.
A new study from Denmark analyzed AS from the perspective of healthcare costs, based on patient utilization of outpatient visits, tests and repeated biopsies (healthcare resources)[iv]. The study cohort consisted of 317 prostate cancer patients. Primary outcomes included the number of patient contacts (with doctor or clinic), PSA tests, biopsies, hospital admissions due to biopsy complications, and patients eventually coming off of AS and undergoing definitive treatment. The secondary outcome was cost.
The authors report that 40% of patients discontinued AS within five years. Patients were to undergo two monitoring biopsies during the first five years of AS, and were seen annually for PSA testing (3-4 times per year). In total, 38 of the 406 biopsy sessions led to hospital admission [due to complications] and of the 317 patients who completed the monitoring biopsies, 87 needed treatment for bladder outlet obstruction.
Regarding the secondary outcome (cost) the authors calculated the total AS costs for an average of 3.7 years’ follow-up per patient, and compared that with what it would have cost had each patient undergone radical prostatectomy. They found that AS represented a 35% reduction in healthcare costs over that period. The research team concluded that taking into account the AS risks of rebiopsy complication, treatment of bladder outlet obstruction, and delayed definitive therapy, AS represents a “potential economic benefit and reduction in the risk of overtreatment compared to immediate radical treatment.”
With the above research in mind, it is reasonable to infer that mpMRI may constitute additional savings by reducing the problems of overdetecting and overdiagnosing indolent disease. Monitoring AS by imaging can prevent unnecessary biopsies and therefore reduce the high price of managing biopsy complications. Imaging offers a great advantage to AS patients, and an economic healthcare benefit.
[i] Johnson L, Choyke P, Figg W, Baris T. The role of MRI in prostate cancer active surveillance. Biomed Res Int. 2014; 2014: 203906. Published online Nov. 30, 2014.
[ii] Klotz L, Vesprini D, Sethukavalan P et al. Long-term follow-up of a large active surveillance cohort of patients with prostate cancer. J Clin Oncol. 2014 Dec 15. pii: JCO.2014.55.1192. [Epub ahead of print]
[iii] Matthews A, Ashfield JE, Morse M, Whelan TF. Five-year follow-up of active surveillance for prostate cancer: A Canadian community-based urological experience. Can Urol Assoc J. 2014 Nov;8(11-12):E768-74. doi: 10.5489/cuaj.2186.
[iv] Thomsen FB, Berg KD, Røder MA, Iversen P, Brasso K. Active surveillance for localized prostate cancer: An analysis of patient contacts and utilization of healthcare resources. Scand J Urol. 2014 Nov 3:1-8.