Active surveillance for early‐stage prostate cancer

Abstract

The natural history of prostate cancer is remarkably heterogeneous and, at this time, not completely understood. The widespread adoption and application of prostate-specific antigen (PSA) screening has led to a dramatic shift toward the diagnosis of low-volume, nonpalpable, early-stage tumors. Autopsy and early observational studies have shown that approximately 1 in 3 men aged >50 years has histologic evidence of prostate cancer, with a significant portion of tumors being small and possibly clinically insignificant. Utilizing the power of improved contemporary risk stratification schema to better identify patients with a low risk of cancer progression, several centers are gaining considerable experience with active surveillance and delayed, selective, and curative therapy. A literature review was performed to evaluate the rationale behind active surveillance for prostate cancer and to describe the early experiences from surveillance protocols. It appears that a limited number of men on active surveillance have required treatment, with the majority of such men having good outcomes after delayed selective intervention for progressive disease. The best candidates for active surveillance are being defined, as are predictors of active treatment. The psychosocial ramifications of surveillance for prostate cancer can be profound and future needs and unmet goals will be discussed. Cancer 2008;112:1650-9.2008 American Cancer Society.KEYWORDS: prostate cancer, active surveillance, review, risk stratification. P rostate cancer is the most common form of noncutaneous malignancy among males in the U.S., and is the second leading cause of cancer mortality, accounting for more than 27,000 deaths in 2007.1 However, the natural history of this disease is remarkably heterogeneous and, at this time, not completely understood. Autopsy studies have shown that approximately 1 in 3 men aged >50 years has histologic evidence of prostate cancer, with up to 80% of these tumors measuring <0.5 cm in size and low in grade, suggesting that the majority are clinically insignificant.2 Approximately 3% of all men will die of prostate cancer, although the mortality from prostate cancer has declined by 31% over the past 13 years.1 The relative contributions of factors responsible for this decline including prostate-specific antigen (PSA) screening, improved detection strategies, and improved treatments are not known.

A Multi-Institutional Evaluation of Active Surveillance for Low Risk Prostate Cancer

“…Based on the modest follow-up in our study (median 29 months) and others (median: 22 -64 months) 4,5,12,19 , caution should be exercised in extrapolating these findings to justify AS as a long-term management strategy. Extended follow-up is mandatory to answer this question, particularly since the Scandinavian Prostate Cancer Group 20 analyzed men with untreated, localized, and primarily palpable prostate cancer, and found local progression and metastases frequently occur 10 -20 years following the diagnosis and cancer-specific mortality rates 15 years after diagnosis are tripled compared to the first 15 years of follow-up 20 .…”

Extended Followup and Risk Factors for Disease Reclassification in a Large Active Surveillance Cohort for Localized Prostate Cancer

“…10,11,19,24 Fewer cohorts reportedly have a median followup of beyond 5 years. 5e7 Our results extend the median followup previously reported in this cohort from 3.6 to 5 years and include more than 200 men with followup beyond 7.5 years.…”

Oncologic outcomes following radical prostatectomy in the active surveillance era

“…In general, candidates include men with clinical stage T1c/ T2a, PSA <10 ng/mL and prostate biopsy Gleason ≤6 in three or fewer cores with ≤50% involvement of any core and a life expectancy <10 to 15 years. [5][6][7] These men were often treated with radical prostatectomy (RP) or radiotherapy prior to widespread AS adoption and, if treated immediately, men with these disease features typically displayed excellent response to RP with 5-year biochemical recurrence-free survival rates ranging from 81% to 92%. 8,9 If AS protocols are followed correctly and the trigger for active treatment is clinical progression out of the very-low-risk category and founded on an oncologic basis rather than patient anxiety, the disease characteristics of the cohort of men being treated with RP would theoretically worsen.…”