Multiparametric magnetic resonance imaging and clinical variables: Which is the best combination to predict reclassification in active surveillance patients?

Introduction & objectives

We tested the role of multiparametric magnetic resonance imaging (mpMRI) in disease reclassification and whether the combination of mpMRI and clinicopathological variables could represent the most accurate approach to predict the risk of reclassification during active surveillance.

Materials & methods

Three-hundred eighty-nine patients (pts) underwent mpMRI and subsequent confirmatory or follow-up biopsy according to the Prostate Cancer Research International Active Surveillance (PRIAS) protocol. Pts with negative (−) mpMRI underwent systematic random biopsy. Pts with positive (+) mpMRI [Prostate Imaging Reporting and Data System, version 2 (PI-RADS-V2) score ≥3] underwent targeted + systematic random biopsies. Multivariate analyses were used to create three models predicting the probability of reclassification [International Society of Urological Pathology ≥ Grade Group 2 (GG2)]: a basic model including only clinical variables (age, prostate-specific antigen density, and number of positive cores at baseline), an Magnetic resonance imaging (MRI) model including only the PI-RADS score, and a full model including both the previous ones. The predictive accuracy (PA) of each model was quantified using the area under the curve.

Results

mpMRI negative (−) was recorded in 127 (32.6%) pts; mpMRI positive (+) was recorded in 262 pts: 72 (18.5%) had PI-RADS 3, 150 (38.6%) PI-RADS 4, and 40 (10.3%) PI-RADS 5 lesions. At a median follow-up of 12 months, 125 pts (32%) were reclassified to GG2 prostate cancer. The rate of reclassification to GG2 prostate cancer was 17%, 35%, 38%, and 52% for mpMRI (−), PI-RADS 3, 4, and 5, respectively (P < 0.001). The PA was 69% and 64% in the basic and MRI models, respectively. The full model had the best PA of 74%: older age (P = 0.023; Odds ratio (OR) = 1.040), prostate-specific antigen density (P = 0.037; OR = 1.324), number of positive cores at baseline (P = 0.001; OR = 1.441), and PI-RADS 3, 4, and 5 (overall P = 0.001; OR = 2.458, 3.007, and 3.898, respectively) were independent predictors of reclassification.

Conclusions

Disease reclassification increased according to the PI-RADS score increase, at confirmatory or follow-up biopsy. However, a no-negligible rate of reclassification was found also in cases of mpMRI (−). The combination of mpMRI and clinicopathological variables still represents the most accurate approach to pts on active surveillance.

The Use of Multiparametric Magnetic Resonance Imaging for Follow-up of Patients Included in Active Surveillance Protocol. Can PSA Density Discriminate Patients at Different Risk of Reclassification?

INTRODUCTION

The objective of this study was to test Prostate Imaging Reporting and Data System (PI-RADS) classification on multiparametric magnetic resonance imaging (mpMRI) and MRI-derived prostate-specific antigen density (PSAD) in predicting the risk of reclassification in men in active surveillance (AS), who underwent confirmatory or per-protocol follow-up biopsy.

MATERIALS AND METHODS

Three hundred eighty-nine patients in AS underwent mpMRI before confirmatory or follow-up biopsy. Patients with negative (-) mpMRI underwent systematic random biopsy. Patients with positive (+) mpMRI underwent targeted fusion prostate biopsies + systematic random biopsies. Different PSAD cutoff values were tested (< 0.10, 0.10-0.20, ≥ 0.20). Multivariable analyses assessed the risk of reclassification, defined as clinically significant prostate cancer of grade group 2 or more, during follow-up according to PSAD, after adjusting for covariates.

RESULTS

One hundred twenty-seven (32.6%) patients had mpMRI(-); 72 (18.5%) had PI-RADS 3, 150 (38.6%) PI-RADS 4, and 40 (10.3%) PI-RADS 5 lesions. The rate of reclassification to grade group 2 PCa was 16%, 22%, 31%, and 39% for mpMRI(-) and PI-RADS 3, 4, and 5, respectively, in case of PSAD < 0.10 ng/mL²; 16%, 25%, 36%, and 44%, in case of PSAD 0.10 to 0.19 ng/mL²; and 25%, 42%, 55%, and 67% in case of PSAD ≥ 0.20 ng/mL². PSAD ≥ 0.20 ng/mL² (odds ratio [OR], 2.45; P = .007), PI-RADS 3 (OR, 2.47; P = .013), PI-RADS 4 (OR, 2.94; P < .001), and PI-RADS 5 (OR, 3.41; P = .004) were associated with a higher risk of reclassification.

CONCLUSION

PSAD ≥ 0.20 ng/mL² may improve predictive accuracy of mpMRI results for reclassification of patients in AS, whereas PSAD < 0.10 ng/mL² may help selection of patients at lower risk of harboring clinically significant prostate cancer. However, the risk of reclassification is not negligible at any PSAD cutoff value, also in the case of mpMRI(-).

Comparison of micro-ultrasound and multiparametric MRI imaging for prostate cancer: A multicenter prospective analysis

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Background: This study aims to compare the sensitivity, specificity, NPV and PPV of mpMRI with the novel high-resolution micro-ultrasound imaging modality. This approach offers the benefits of simplicity, a single intervention for imaging and biopsy, leveraging the low cost of ultrasound. Micro-ultrasound may be used to image suspicious lesions and target biopsies in real-time with or without additional MRI-based targets. Methods: Data from 9 sites was aggregated, totaling 866 subjects presenting for ExactVu micro-ultrasound guided biopsy with available mpMRI studies. Samples in all subjects were taken from mpMRI targets and micro-ultrasound targets, with up to 12 systematic samples filled in. Various strategies were used for mpMRI target sampling including cognitive fusion with micro-ultrasound, separate software-fusion systems, and software-fusion using the micro-ultrasound FusionVu system. Clinically significant cancer was considered any Gleason Sum > 6 and targeted samples were taken for PI-RADS > 2 or PRI-MUS1 > 2 lesions. Results: Overall, 39% of all biopsy cases were positive for clinically significant PCa. mpMRI demonstrated 89% sensitivity and NPV of 77%. Compared to mpMRI, micro-ultrasound sensitivity (95%) and NPV (87%) were higher. Micro-ultrasound was less specific (21% vs 23% for mpMRI) with similar PPV (44% vs 43%). The aggregate effect demonstrates higher sensitivity for csPCa with micro-ultrasound compared to mpMRI (p<0.01). Conclusions: Micro-ultrasound is an attractive option for screening and targeted biopsy. Sensitivity and NPV appear superior to MRI, but specificity is mildly reduced. Further larger-scale studies are required for validation of these findings. References: Ghai, S. et al., “Assessing Cancer Risk in Novel 29 MHz Micro-Ultrasound Images of the Prostate”, Journal of Urology, 2016 Aug;196(2):562-9. Clinical trial information: NCT03938376.

High-dimensional single cell-based immune profiling of the tumor immune microenvironment in prostate cancer

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Background: Genetic lesions that drive prostate cancer (PCa) development are able to modify the immune response and tumor infiltrating immune subsets, resulting in tumor progression. We investigated the profile of the immune microenvironment in PCa by high dimensional single cell analysis. Methods: We conducted an immune profiling study based on integrated RNA single cell sequencing and multiparametric flow cytometry in order to dissect the immune landscape of PCa. CD45+ immune cells infiltrating tumoral and adjacent non tumoral tissues were isolated from patients with PCa who underwent software assisted fusion biopsy, based on MRI, and/or radical prostatectomy, and analyzed by single cell sequencing. The primary endpoint was to evaluate the effectiveness of single cell RNA sequencing on CD45+ cell sorted from tumoral and adjacent non-tumoral tissues. Secondary endpoint was the identification of tumor-driven immune changes in prostatic lesions. Results: The cohort consisted of 3 patients who underwent radical prostatectomy (RP) and 45 patients with positive prostate biopsy; the negative control was checked by pathological assessment. In patients who underwent RP the gene expression analysis identified a modulation in the abundance of several immune subsets infiltrating the tumoral tissue, when compared with the non tumoral, evident for Tumor associated macrophages (TAMs), Natural Killer cells (NK) and T regulatory cells. We then implemented a 22 parameters flow cytometry panel that we tested on fresh prostatic tissue and peripheral blood from positive PCa biopsies. We identified a subset of tumor infiltrating macrophages showing an altered gene expression profile when compared with macrophages infiltrating the non-tumoral tissue. Importantly we derived a genetic signature from this subset of tumoral TAMs that resulted to be associated with cancer progression. Conclusions: Our findings support the effectiveness of single cell RNA sequencing in the dissection of the immune landscape in PCa and identified immune changes in patients when comparing neoplastic tissue with non tumoral areas. Such data may be useful for understanding the role of immune system in PCa carcinogenesis.

TMPRSS2: ERG expression in prostate cancer—Imaging and clinicopathological correlations

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Background: The TMPRSS2:ERG gene fusion (T:E) is found in up to 70% of prostate cancers (PCa) and results in androgen dependent overexpression of ERG, promoting tumor growth. The early identification of T:E may be helpful even in low-risk PCa. Although T:E can be non-invasively detected in urine, its correlation with new imaging tools (MRI and high-frequency ultrasound) and clinical outcome remains vague.This study investigates T:E expression in patients scheduled for random/software-assisted MRI or micro-ultrasound (29Mhz) fusion biopsy. Methods: This is a prospective cohort study in patients with suspected PCa enrolled between 2016 and 2019, approved by local authorities with Prot. N. 336/19, 14/05/2019. Patients underwent systematic US-guided biopsy, plus targeted biopsy if they had ³1 suspicious lesion (PI-RADS V.2 >2) at mpMRI or PRIMUS >2 at MICRO-US. For each patient, 1 prostatic core from the highest PI-RADS or PRIMUS lesion was collected for T:E analysis (a core from the right lobe in negative patients). Histological analyses were performed by experienced genitourinary pathologists. RNA was extracted from a dedicated fresh biopsy and RT-PCR was performed with different primer couples to detect the most frequent T:E fusions. All amplified products were checked by sequencing. Results: The cohort consists of 92 patients (median PSA 7.13 ng/ml, IQR 5.25-11.04 - average age 65ys), 81 with a diagnosis of PCa after biopsy. mpMRI was performed on 63 (68.5%) patients and was positive in 58 (92%), who underwent fusion biopsy. T:E fusion transcripts were detected in 23.5% of individuals with a diagnosis of PCa. Among patients positive for T:E, those analyzed by MRI were 100% positive (73% PI-RADS ≥4), those analyzed by MICRO-US were 83% positive. Sensitivity of the T:E assay for any PCa was 23.5%, specificity 100%, with negative and positive predicting values of 15% and 100%. There was no correlation between T:E and family history, PSA, PIRADS, PRI-MUS and Gleason score. Conclusions: Our finding showed a 100% of specificity making T:E an attractive tool for early cancer detection. In the future, identification of T:E in semen could represent a screening test for clinical stratification of patients with suspected PCa.

Renal Function Loss After Cryoablation of Small Renal Masses in Solitary Kidneys: European Registry for Renal Cryoablation Multi-Institutional Study

Objectives: To estimate and quantify the loss of kidney function in solitary kidneys with small renal masses (SRMs) after laparoscopy-assisted renal cryoablation (LARC), from the European Registry for Renal Cryoablation (EuRECA) database. Patients and Methods: Of the 808 patients from eight European centers in the database, 102 patients had SRMs in solitary kidneys. Patient demographics, body mass index (BMI), American Society of Anesthesiologists (ASA) grade, Charlson comorbidity index, and tumor characteristics including nephrometry (PADUA) score where available were collected. Renal function data in the form of estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD) stratification both preoperatively and at 3 months postoperatively were collected. Results: The median (interquartile range [IQR]) age was 67 (59-81) years, the median (IQR) BMI was 26 (23.9-28.9) kg/m², and the median (IQR) ASA score was 2 (2-3). The median Charlson score was 4 (range: 0-10). The median (IQR) tumor size in cross-sectional imaging was 26 (19-38) mm. The follow-up data were available for 72 patients with a median follow-up for this group of 38 (range: 10-132) months. The mean preoperative eGFR was 55.0 mL/minute/1.73 m² (standard deviation [SD] = 18.1), and the mean postoperative eGFR was 51.8 mL/minute/1.73 m² (SD = 18.8). The change was -3.1 mL/minute/1.73 m² (95% confidence interval -5.2 to -1.0) units, which was statistically significant (p = 0.004). The change in the CKD stages comparing before and after LARC was not significant (paired two-tailed t-test, p = 0.06). Critically, the decrease in the eGFR did not translate to any significant adverse outcome and zero patients required dialysis. Conclusion: To the best of our knowledge, this is the largest study of renal function after LARC in SRMs in solitary kidneys. Cryotherapy in this imperative situation is safe, carries clinically insignificant reduction in renal function, therefore providing an option to minimize the risk of developing renal failure necessitating dialysis.

Predictive factors for progression of patients with carcinoma in situ of the bladder at long-term follow-up: pure versus non-pure CIS

BACKGROUND

The aim of this study was to identify the predictive factors for progression defined as any event that shifted the management of the disease from a bladder sparing approach, by comparing patients with pure versus non-pure carcinoma in situ (CIS) of the bladder.

METHODS

A retrospective analysis was carried out in consecutive patients affected by newly-diagnosed pure CIS and non-pure CIS (excluding cases with concomitant muscle invasive cancer). All patients were enrolled a in our institution from 1998 to 2010. Data was prospectively collected. Main end point was progression-free survival.

RESULTS

Overall, 149 patients with CIS were identified for the analysis. A total of 98 patients had pure CIS (66%). Median follow-up was 103 months (range: 40-206 months). Progression occurred in 29 patients (19%). A total of 30 patients died during the follow-up (20%). In 13 cases (9%), the death was cancer specific. Progression-free survival estimate was 181 months (95% CI: 169-193 months) and 154 months (95% CI: 133-176 months) respectively for pure and non-pure CIS population (P=0.03). Among examined variables (age, gender, symptoms, smoking habit, ASA score, number of bacillus Calmette-Guérin [BCG] instillations), multivariate analysis disclosed that only CIS type was an independent predictor of progression (P=0.03) with a relative risk of 0.37 in favor of pure CIS.

CONCLUSIONS

Pure and non-pure CIS are efficiently treated by BCG therapy combined with trans-urethral resection and/or radical cystectomy, with relatively low rate of progression. CIS type was the only significant predictor of progression.

Screening of BRCA2 mutated men for detection of prostate cancer: Preliminary results from a national high volume cancer center

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Background: Up to 10% of cases of Prostate Cancer (PCa) are hereditary. Germline pathogenic mutations in BRCA2 gene confer the highest risk (2.5 to 8.6 fold in men ≤ 65 yr). Beyond periodic Prostate Specific Antigen (PSA) dosage and digital rectal examination (DRE), a targeted screening for carriers is still undefined. Prostate Health Index (PHI), a combination of the tPSA, fPSA and proPSA tests, may be a more accurate biomarker than PSA only to detect PCa. We evaluated how to better screen BRCA2 mutated men for PCa. Methods: We reviewed the genealogical trees of all women tested positive for germline BRCA2 pathogenic mutation at our clinic. We offered targeted BRCA2 mutational analysis to all first/second degree relative men between 40 and 69 yr. A targeted screening program (annual PSA and PHI dosages and DRE) was proposed to all men tested positive. In case of PSA and/or PHI values out of range ( > 4ng/ml and > 20, respectively) we proceeded with a multiparametric Magnetic Resonance Imaging (mpMRI) and fusion biopsy of suspected lesions. Results: From June 2008 to October 2018 610 breast/ovarian cancer patients had BRCA test: 35 (5.7%) tested positive for BRCA1 pathogenic mutation, 32 (5.2%) for BRCA2 pathogenic mutation. From October 2017 90 relatives were checked for the familial mutation and 24 (27%) (12 women, 12 men) tested positive for BRCA2 mutation. All the 12 men (median age 48 yr, IQR 44 to 60) accepted to join our screening program. During the first year all men had negative DRE. Median PSA was 0.70 (IQR 0.43 to 1.02), median PHI was 17.56 (IQR 11.85 to 24.06). One patient with out of range PHI value already had mpMRI resulted negative. During the second year 4 men underwent screening so far: they had negative DRE. Median PSA was 0.57 (IQR 0.38-0.77), median PHI was 16.88 (IQR 11.87-21.90). Two men had PHI out of range and will undergo mpMRI. Conclusions: An accurate review of the genealogical trees of breast/ovarian cancer BRCA2 mutated patients allows to identify male relatives potentially carriers of the same mutation. These men have a high lifetime risk of PCa and require an appropriate screening, currently absent. Our approach may be leveraged as proof of concept of selection and screening program in carriers of BRCA2 mutations.

Gender-specific risk factors for renal cell carcinoma: a systematic review

PURPOSE OF REVIEW

The relationship between gender and kidney cancer incidence/outcomes has been largely evaluated and may significantly impact the management of patients diagnosed with these tumors. We reviewed and summarized the most relevant recent publications reporting about this clinically meaningful relationship.

RECENT FINDINGS

The incidence of kidney cancer is higher in men than in women. Male gender is clearly associated with more aggressive histological characteristics both in terms of tumor stage and grade. Similarly, male gender has been found to be associated with worse perioperative and oncological outcomes. Several genetic and molecular markers that may partly explain these observed differences have been evaluated. However, the impact of these markers on clinical practice has not been clearly demonstrated.

SUMMARY

Gender is significantly associated with kidney cancer incidence, characteristics and outcomes. Future efforts are still needed to explore the biological and molecular basis underlying of this relationship.

Robot-assisted Partial Nephrectomy for Complex (PADUA Score ≥10) Tumors: Techniques and Results from a Multicenter Experience at Four High-volume Centers

BACKGROUND

Robot-assisted partial nephrectomy (RAPN) represents a widely accepted minimally invasive alternative to open and laparoscopic surgery for the treatment of clinically localized renal tumors.

OBJECTIVE

To assess the feasibility of RAPN in a contemporary series of patients with highly complex tumors (PADUA score ≥10) treated at four high-volume robotic surgery institutions.

DESIGN, SETTING, AND PARTICIPANTS

Data from a prospectively maintained multi-institutional database on patients subjected to RAPN between 2010 and 2017 were reviewed. For the scope of this analysis, only patients with highly complex renal tumors, defined as a PADUA score between 10 and 14, were included.

SURGICAL PROCEDURE

RAPN was performed with the da Vinci Si or Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA) using novel technologies such as TilePro and near-infrared fluorescence imaging.

MEASUREMENTS

Intraoperative, postoperative, surgical, and oncological outcomes were collected. Predictors of optimal surgical outcomes defined according to the Margin Ischemia and Complications binary system (absence of Clavien-Dindo >2 complications, warm ischemia time [WIT] <20min, and absence of positive surgical margins) were determined using logistic regression models (LRMs).

RESULTS AND LIMITATIONS

Overall, 255 patients with complex renal tumors were included. The mean operative time was 165min and mean WIT was 18.6min. Overall, WIT was longer than 20min in 86 (33.7%) individuals, while a Clavien-Dindo >2 complication and positive surgical margins were observed in 13 (5.1%) and four (out of 211 patients with malignant histotypes; 1.9%) individuals, respectively. Optimal surgical outcomes were achieved in 158 (62.0%) patients. At a median follow-up of 28mo, one (0.4%) local and two (0.8%) distant recurrences of the disease were observed. In multivariable LRMs, extremely complex tumors (PADUA score 12-13) were associated with an increased likelihood of not achieving optimal outcomes (odds ratio: 2.31; p=0.024). Besides tumor complexity, male gender was also associated with a two-fold higher risk of not achieving optimal surgical outcomes (p=0.029).

CONCLUSIONS

In experienced hands, RAPN can be considered as an effective treatment option even in cases of complex renal lesions. However, increasing tumor complexity may affect the surgical outcomes in this highly selected patient population.

PATIENT SUMMARY

We reported our multicentric experience with robot-assisted partial nephrectomy (RAPN) in patients with complex renal tumors. We demonstrated that, in experienced hands, RAPN is a feasible and safe treatment option even in such patients. Novel technologies applied to RAPN may further extend the indications without compromising the outcomes.

Early Catheter Removal After Robot-assisted Radical Prostatectomy: Results from a Prospective Single-institutional Randomized Trial (Ripreca Study)

BACKGROUND

The adoption of robotic technology in the treatment of prostate cancer (PCa) could lead to improvement in outcomes.

OBJECTIVE

To evaluate feasibility, to compare functional outcomes, and to assess the economic benefits of removing catheter on the postoperative day (POD) 3 versus POD 5 after robot-assisted radical prostatectomy (RARP).

DESIGN, SETTING, AND PARTICIPANTS

From September 2016 to May 2017, patients selected to undergo RARP for clinically localized PCa at a high-volume center were prospectively randomized into group 1 (POD 3; n=72) versus group 2 (POD 5, n=74).

INTERVENTION

All patients underwent RARP with anatomical posterior and anterior reconstruction.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was to compare acute urinary retention (AUR) and urinary leakage rate in the two groups. The secondary endpoints were early and mid-term postoperative functional outcomes assessed through questionnaires (ICIQ-MLUTS, IPSS), early continence rate, and postoperative pain/discomfort (visual analog scale score). The economic impact of early catheter removal was also assessed.

RESULTS AND LIMITATIONS

AUR was reported in two (1.4%) cases, one for each study group (p=0.9). One case of vesicourethral leakage was reported (0.7%) in group 1. Urethral discomfort and pain at discharge was significantly higher in group 2 (p=0.03). In our clinical practice, POD 3 catheter removal approach would determine a saving of approximately €80 000 and 405 d of hospitalization yearly. The main limitation is the small sample size.

CONCLUSIONS

Early catheter removal after RARP does not lead to an increase in perioperative complications. No negative effect on early and mid-term functional outcomes was observed. A significant impact on saving economic resources was reported.

PATIENT SUMMARY

We demonstrated that early catheter removal has no negative effect on spontaneous voiding, complications, or urinary continence recovery after robot-assisted radical prostatectomy.

Long-term outcomes of high-grade T1 bladder cancer treated with intravesical bacillus Calmette-Guérin: experience of a single center

BACKGROUND

To assess the outcomes of patients with high-grade (HG) pT1 bladder cancer (BC) treated with intravesical BCG therapy.

METHODS

The study population consisted of 185 patients with HG pT1 BC treated between 1998 and 2010. We aimed to determine recurrence-free (RFS) and progression-free survival (PFS), as well as the predictors of RFS and PFS.

RESULTS

Overall, 143 (77.3%) patients were males. Median age was 72 years (IQR: 66-78). Tumor size was ≥3 cm in 100 (54.1%) individuals. Most patients had single tumors (125; 67.6%). Primary, progressive and recurrent patterns of presentation were observed in 146 (78.9%), 21 (11.4%), and 18 (9.7%) cases, respectively. After 2nd-look TURB, 127 (68.6%) patients had no residual disease, 44 (23.8%) had Ta/CIS, and 14 (7.6%) had T1 HG BC. Twenty-two (11.9%) patients experience early recurrence after BCG. Of these, 12 patients (54.5%) were diagnosed with Ta/CIS, while 10 (45.5%) were diagnosed with HG pT1 BC. The median follow-up was 93 months (IQR: 63-147). Ten-year RFS and PFS rates were 69.6 and 79.2%. In multivariable Cox regression models, female gender (HR=2.41; P=0.001), progressive (HR=2.03; P=0.030) and recurrent (HR=3.87; P<0.001) pattern of presentation emerged as independent predictors of RFS, while age ≥70 years (HR=2.13; P=0.027), presence of multiple tumors (HR=2.06; P=0.019), and early recurrence (HR=3.88; P<0.001) emerged as independent predictors of PFS.

CONCLUSIONS

Intravesical BCG appears to be an effective treatment for HG pT1 BC. Caution should be used in patients aged ≥70 years, with multiple tumors or experiencing early recurrence.

Pathological Outcomes for Patients Who Failed To Remain Under Active Surveillance for Low-risk Non-muscle-invasive Bladder Cancer: Update and Results from the Bladder Cancer Italian Active Surveillance Project

BACKGROUND

It has been shown that active surveillance (AS) is feasible and effective in a subset of patients with recurrent low-grade (LG) non-muscle-invasive bladder cancer (NMIBC).

OBJECTIVE

To update a previous preliminary series and investigate pathological outcomes for patients who failed to remain on AS.

DESIGN, SETTING, AND PARTICIPANTS

Prospective observational cohort study started in February 2008, and currently still active, at a tertiary university hospital, including patients with pathologically confirmed NMIBC who experienced recurrence during follow-up.

INTERVENTION

AS monitoring consisted of cytology and in-office flexible cystoscopy every 3 mo for the first year, and every 6 mo thereafter.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint was pathological results for patients who failed to remain on AS. The secondary outcome was an update of clinical results from our previous series. Data were complemented by descriptive statistical analysis and univariable and multivariable proportional hazards Cox regression.

RESULTS AND LIMITATIONS

Overall, 167 patients were included. Of 181 AS events, 61 (33.7%) were deemed to require treatment because of positive cytology (n=10), gross haematuria (n=11), and increases in the tumour number (n=15), or size (n=17), or both (n=8). The median time on AS was 12 mo (interquartile range 4-26). Pathological specimens from AS failures did not show any malignancy in 20 cases. Histopathology identified urothelial hyperplasia and oedema, submucosal vascular ectasia, mucosal erosion, polypoid cystitis, von Brunn nest hyperplasia, and squamous metaplasia. The time from first transurethral resection to AS start was inversely associated with recurrence-free survival (hazard ratio 0.97, 95% confidence interval 0.96-1.00; p=0.024). The study lacks statistical subanalyses focusing on patients with failure and negative neoplastic pathological outcomes.

CONCLUSIONS

AS might be a reasonable strategy in patients presenting with small LG pTa/pT1a recurrent bladder tumours. Approximately 30% of patients deemed to have AS failure did not harbour any neoplastic lesion, strengthening the role of AS.

PATIENT SUMMARY

Patients with small low-grade pTa/pT1a recurrent papillary bladder tumours could benefit from an active surveillance protocol with no significant risk of pathological progression to muscle-invasive cancer.