# Active Surveillance for Localized Prostate Cancer ## Overview Active surveillance (AS) for localized prostate cancer involves carefully selecting patients based on specific inclusion criteria, implementing structured monitoring protocols, identifying triggers for intervention, and understanding long-term outcomes. A critical aspect of managing AS programs is addressing patient anxiety and ensuring adherence to surveillance schedules to optimize both oncologic safety and quality of life. --- ## Rationale for Active Surveillance Prostate cancer is often overdiagnosed and overtreated, particularly in cases classified as Grade Group 1 (Gleason 3+3=6), which has an almost negligible risk of metastasis over 10 to 15 years. Radical treatments such as surgery or radiation carry significant risks, including erectile dysfunction in 30-70% of patients, urinary incontinence in 5-20%, and bowel toxicity related to radiation. Active surveillance defers immediate treatment while closely monitoring for any signs of disease progression or reclassification. It is important to distinguish AS from watchful waiting: AS involves structured, regular monitoring with the intent to cure if progression occurs, whereas watchful waiting is a less intensive approach aimed at symptom management in men who are either unfit for or decline curative treatment. --- ## Key Landmark Trials The ProtecT trial randomized 1,643 men to active monitoring, radical prostatectomy, or radiation therapy, with 15 years of follow-up. Prostate cancer mortality was very low across all groups, approximately 3%. However, active monitoring was associated with higher rates of metastasis (9.4%) compared to surgery (4.7%) and radiation (5.0%). Despite similar overall survival, the increased progression and metastasis rates highlight the need for careful patient selection and monitoring. A limitation of this trial was that it preceded the widespread use of MRI-guided biopsies and the Grade Group system, which now improve risk stratification. The Goteborg AS cohort (SPCG-17), a large Scandinavian prospective study, utilized an MRI-based surveillance protocol and demonstrated the safety of MRI-driven surveillance, showing low rates of reclassification leading to treatment. Similarly, the DETECTIVE trial and the Canary PASS study are prospective multicenter cohorts evaluating the integration of MRI and genomic classifiers into surveillance protocols, aiming to refine patient selection and monitoring strategies. --- ## Inclusion Criteria Most guidelines, including those from the AUA and NCCN, recommend AS primarily for men with Grade Group 1 prostate cancer (Gleason 3+3=6), PSA levels below 10 ng/mL, clinical stage T1c to T2a, and limited disease burden defined as two to three or fewer positive biopsy cores with no more than 50% cancer involvement in any single core. Some protocols also require a PSA density below 0.15 ng/mL/cc and a life expectancy greater than 10 years, as men with shorter life expectancy may be better suited for watchful waiting. Expanded criteria now include select patients with favorable intermediate-risk disease, specifically those with Grade Group 2 (Gleason 3+4=7) exhibiting low-volume disease, a low percentage of pattern 4, and absence of cribriform or intraductal carcinoma (IDC-P). Genomic classifiers such as Decipher and Oncotype DX can support decision-making in these cases. The NCCN 2024 guidelines have incorporated favorable intermediate risk as a consideration for AS. Patients are excluded from AS if they have Grade Group 3 or higher, presence of cribriform pattern or IDC-P on biopsy, high PSA density (greater than 0.15-0.20), high-volume disease (more than three positive cores or over 50% involvement in any core), or inability to comply with follow-up protocols. | Criteria | Standard AS (Grade Group 1) | Expanded AS (Select Grade Group 2) | |---|---|---| | Gleason score | 3+3=6 (GG1) | 3+4=7 (GG2) with favorable features | | PSA | <10 ng/mL | <10 ng/mL | | Clinical stage | T1c-T2a | T1c-T2a | | Tumor volume | ≤2-3 positive cores, ≤50% any core | Low-volume pattern 4 | | PSA density | <0.15 ng/mL/cc | <0.15 ng/mL/cc | | Histology | No cribriform/IDC-P | No cribriform/IDC-P; low % pattern 4 | | Genomic classifiers | Supportive (not required) | Recommended (low genomic risk) | --- ## Monitoring Protocol PSA levels are monitored every 3 to 6 months during the first two years of surveillance, then every 6 to 12 months thereafter. While absolute PSA values are recorded, PSA kinetics—such as doubling time—are more informative; a PSA doubling time under three years is concerning and warrants further evaluation. PSA density should be recalculated as prostate volume changes. Digital rectal examinations (DRE) are performed every 6 to 12 months. The detection of a new nodule or clinical upstaging to T2b or higher may prompt a biopsy. Multiparametric MRI is recommended at enrollment if not previously done and repeated every 1 to 2 years. The development of new PI-RADS 4 or 5 lesions on MRI triggers targeted biopsy. MRI enhances detection of anterior and apical tumors often missed by systematic biopsy and improves identification of disease reclassification. Surveillance biopsies include a confirmatory biopsy within 6 to 12 months of diagnosis, which is critical as up to 25-30% of men are reclassified at this stage. This biopsy should combine MRI-targeted cores (if lesions are visible) with systematic cores. Subsequent biopsies are performed every 1 to 3 years depending on the protocol, with the AUA recommending no more than annual routine biopsies guided by MRI findings and PSA kinetics. The NCCN advises confirmatory biopsy within 6 to 12 months followed by risk-adapted surveillance biopsies. Some protocols employ saturation biopsies with extended templates (12 or more cores) for confirmation. Genomic classifiers such as Decipher, Oncotype DX GPS, and Prolaris can be performed on initial biopsy tissue. Low genomic risk supports continued surveillance, while high genomic risk may prompt treatment even without histologic reclassification. Although not yet standard of care, these tools are increasingly integrated into surveillance protocols. --- ## Triggers for Intervention (Reclassification) The most important triggers for intervention are pathologic changes identified on repeat biopsy. These include upgrading to Grade Group 2 or higher (Gleason 3+4=7 or above), an increase in tumor volume defined as more than three positive cores or over 50% involvement in any core, and the appearance of cribriform pattern or intraductal carcinoma. Any finding of Grade Group 3 or higher also warrants treatment consideration. PSA and clinical findings can also prompt further evaluation. A rapid PSA rise with a doubling time under three years should lead to repeat biopsy rather than immediate treatment. The emergence of a new palpable nodule on DRE or MRI progression, such as a new PI-RADS 4 or 5 lesion or growth of an existing lesion, similarly triggers biopsy. Patient-driven factors, particularly anxiety and preference for definitive treatment, are common reasons for discontinuing AS. Up to 10-20% of patients leave surveillance due to anxiety rather than disease progression, underscoring the importance of psychological support and counseling within AS programs. --- ## Outcomes of Active Surveillance Treatment-free survival rates indicate that 50-70% of men remain on AS at 5 years, 40-55% at 10 years, and 30-40% at 15 years. Most conversions to treatment occur within the first 2 to 5 years, often triggered by reclassification on confirmatory biopsy. Oncologic outcomes are excellent, with cancer-specific survival rates between 98% and 99.5% at 10 to 15 years and metastasis-free survival exceeding 95% at 10 years. Delayed treatment within surveillance protocols does not appear to compromise curability, as the window for curative intervention is maintained when protocols are properly followed. Functional outcomes during AS are favorable, with preservation of sexual function and continence. When treatment is eventually pursued, outcomes are comparable to those of upfront treatment, providing a cumulative benefit of years of preserved quality of life. --- ## Special Populations Younger men under 55 years face a longer time horizon, increasing their cumulative risk of reclassification. Many remain appropriate candidates for AS if they meet strict criteria and may benefit from genomic classifier testing to confirm low risk. More frequent monitoring may be warranted in this group. African American men have been reported in some studies to experience higher rates of reclassification on AS and may present with more aggressive disease at younger ages. AS remains appropriate if criteria are met, but closer monitoring is recommended. Some experts advocate for a lower threshold for confirmatory biopsy and genomic testing in this population. --- A timeline diagram showing a typical active surveillance protocol over 5 years. The x-axis represents time from diagnosis, with icons and labels for each monitoring event: PSA checks (every 3-6 months, shown as blood draw icons), DRE (every 6-12 months), MRI (at enrollment, year 1-2, then every 1-2 years), confirmatory biopsy (at 6-12 months), and subsequent surveillance biopsies (every 1-3 years). Decision points are marked where triggers for intervention are evaluated. Color-coded zones indicate the first critical 2 years vs. long-term surveillance phase. A Venn diagram or decision matrix illustrating the inclusion criteria for active surveillance in prostate cancer. Three overlapping circles represent Grade Group 1 criteria (Gleason 3+3=6, PSA <10, T1c-T2a, low volume), expanded criteria for Grade Group 2 (Gleason 3+4=7 with favorable features), and exclusion criteria (cribriform, IDC-P, high volume, GG3+). Annotations show the role of genomic classifiers in supporting decisions at the boundary between AS and treatment. Clean infographic style with clinical data labels. A bar graph comparing treatment-free survival rates on active surveillance at 5, 10, and 15 years from major AS cohorts (Johns Hopkins, Sunnybrook, PRIAS, UCSF, Royal Marsden). Alongside, a second panel shows cancer-specific survival rates exceeding 98% across all cohorts, reinforcing the safety of AS. Labeled axes and data source citations for each cohort. Professional publication-quality figure. --- ## Clinical Pearls The confirmatory biopsy performed within 6 to 12 months of diagnosis is the single most important step in active surveillance, as it identifies up to 30% of men who were undergraded on the initial biopsy. It is essential to understand that active surveillance is distinct from watchful waiting; AS is conducted with curative intent through structured monitoring, whereas watchful waiting is palliative, with treatment initiated only upon symptom development. The advent of MRI has transformed AS by detecting lesions missed on initial systematic biopsy and reducing unnecessary repeat biopsies when MRI findings remain stable. The presence of cribriform pattern 4 and intraductal carcinoma on biopsy are exclusion criteria at most centers because these features predict aggressive disease behavior. Patient anxiety is the leading non-medical reason for discontinuing AS, making structured counseling, support groups, and clear communication about the safety of surveillance vital components of management. While Grade Group 2 (Gleason 3+4=7) with favorable features is increasingly considered for AS, strict criteria must be met, including low-volume pattern 4, absence of cribriform or IDC-P, and ideally low genomic risk. Finally, PSA kinetics alone should not trigger treatment but rather prompt repeat imaging and biopsy to confirm or refute disease reclassification. --- ## References - Hamdy FC, et al. Fifteen-year outcomes after monitoring, surgery, or radiotherapy for prostate cancer (ProtecT). N Engl J Med. 2023;388(17):1547-1558 - Klotz L, et al. Active surveillance for low-risk prostate cancer: long-term results from the Sunnybrook cohort. J Clin Oncol. 2015;33(3):272-277 - Tosoian JJ, et al. Active surveillance for prostate cancer: current evidence and contemporary state of practice. Nat Rev Urol. 2016;13(4):205-215 - AUA/ASTRO/SUO Guideline: Clinically Localized Prostate Cancer, 2022 - NCCN Clinical Practice Guidelines in Oncology: Prostate Cancer, Version 4.2024