Clinical Risk Factors Associated With Small Renal Mass Malignant Histology in a Multi-Ethnic Population Undergoing Partial Nephrectomy

INTRODUCTION

Small renal masses (SRMs) are often incidentally diagnosed, and a large proportion are malignant. However, there is a paucity of data describing predictors of malignancy in minority patients with SRMs. Thus, our goal was to examine clinical risk factors associated with SRM malignant histology in patients undergoing partial nephrectomy (PN) a diverse, urban academic center.

MATERIALS AND METHODS

Patients with a SRM undergoing PN at a single institution between 2010 to 2018 were reviewed. Demographic, clinical, and imaging characteristics were compared to pathology results. Logistic regression was used to examine associations between demographic/clinical variables for malignant and high-grade histology.

RESULTS

In total, 331 patients who underwent PN for SRM were included. Of those, 264 (79.8%) had malignant histology while 67 (20.2%) had benign histology. The proportions of men and of current smokers were significantly higher among patients with malignant histology. In multivariate models, non-Hispanic Black (NHB) patients had increased odds of having malignant histology (OR 2.46, 95% CI: 1.01-5.99, P = .048) and current smokers (OR = 4.02; 95% CI 1.14-14.18, P = .031). Hispanic patients had a 3-fold increased risk of high-grade RCC (OR 3.06, 95% CI: 1.19-7.87, P = 0.02) compared to Non-Hispanic White patients.

CONCLUSION

In our population, male sex, smoking, and NHB race/ethnicity was associated with an increased risk of malignancy in patients undergoing partial nephrectomy for SRM. Older age and Hispanic race/ethnicity were associated with high grade RCC. Our results suggest that urologists should exercise a higher level of vigilance in managing and treating SRM among NHB and Hispanic patients.

Rates of False-Negative Screening in Prostate Specific Antigen Secondary to 5-Alpha Reductase Inhibitor Usage: A Quality-Improvement Initiative

PURPOSE

Patients often take 5-alpha reductase inhibitors (5-ARIs) for the management of benign prostatic hyperplasia. However, 5-ARIs can decrease prostate specific antigen (PSA) by approximately half and therefore may lead to false negative PSA tests. We investigated false-screening rates in men on 5-ARIs undergoing PSA testing and whether ordering physicians noticed false negative findings.

MATERIALS AND METHODS

A single institution, retrospective study was conducted on patients with a PSA value documented between 2014 and 2017. Patient demographics, PSA results, 5-ARI usage, and providing clinician characteristics were collected. Published normal PSA values were used to determine PSA test positivity; values for those on 5-ARIs were doubled.

RESULTS

A total of 29,131 men were included. 1,654 (5.7%) were prescribed 5-ARIs at least 12 months prior to PSA evaluation. 118 men (7.1%) had a value that would be positive if corrected for 5-ARI usage, 33 (27.9%) of which had no indication that the provider had noted this. There was no effect on rates of false negative values if the PSA was ordered by a different provider than the one who prescribed the 5-ARI (p = 0.837). However, if the provider who ordered the PSA test was an urologist, the likelihood that a false negative value would be identified was lower (p=0.001).

CONCLUSIONS

More than a quarter of men with false negative tests were missed. This occurred more often when the ordering provider was not an urologist. An educational opportunity exists to improve the quality of PSA testing by preventing false negative tests.

Does Glomerular Filtration Rate at Discharge After Partial Nephrectomy Predict Long-Term Glomerular Filtration Rate Stability?

Introduction: Being able to predict glomerular filtration rate (GFR) plateau after partial nephrectomy (Pnx) is an important goal in providing patients with a confident projection of maintained renal function. As such, in an ethnically and socioeconomically diverse, inner city cohort of patients undergoing Pnx, we compared preoperative (pre-op) and day of discharge (DC) GFR to that of long-term GFR measured at 12-18 months to evaluate postoperative (post-op) GFR stability. Methods: A total of 162 patients who had undergone minimally invasive Pnx at a single institution between 2010 and 2016 were reviewed. Patients with the following available measurements were included: pre-op GFR, DC GFR, and long-term GFR (12-18 months after DC). Multivariate linear regression was performed to assess factors predictive of long-term GFR, including estimated blood loss, warm ischemic time, tumor size, length of stay, pre-op GFR, DC GFR, race, chronic kidney disease, diabetes mellitus, and hypertension. Results: Mean pre-op GFR, DC GFR, and long-term GFR were 70.754, 68.326, and 66.526 mL/(minute ·1.73 m²), respectively. Mean GFR change was -4.228 pre-op to long term and -1.800 DC to long term. No significant difference was observed between means of DC GFR and long-term GFR (p = 0.248) as well as between means of pre-op GFR and DC GFR (p = 0.062). A significant difference was observed between pre-op GFR and long-term DC GFR (p = 0.002). On multivariate analysis, both pre-op GFR (β = 0.532; 95% confidence interval [CI] = 0.256-0.808; p ≤ 0.001) and DC GFR (β = 0.312; 95% CI = 0.089-0.537; p = 0.007) were found to be strong predictors of long-term GFR (R² = 0.608). Conclusions: Long-term GFR in a highly ethnically diverse inner city population recovering from Pnx is stable relative to GFR measured at DC from the hospital. Our findings demonstrate that patients experience a GFR plateau after surgery, resulting in minimal change in renal function at a mean of 14 months post-op.

A comparison of perinephric fat surface area and Mayo Adhesive Probability score in predicting malignancy in T1 renal masses

INTRODUCTION

Recent studies have proposed that nearby fat deposits may have metabolic influence on kidney cancer pathobiology. Both fat quantity and quality may play unique roles in this complex relationship. As such, we investigated whether perinephric fat surface area (PFA), a quantitative measure of fat, or Mayo Adhesive Probability (MAP) score, a qualitative measure, were predictive of malignant pathology or Fuhrman grade in small renal masses.

METHODS

A total of 317 patients undergoing minimally invasive partial nephrectomy between 2010 and 2016 for renal masses were retrospectively reviewed. Preoperative abdominal CT and MRI scans were measured for PFA and MAP scores. Multiple binary logistic regression models were created to identify predictive factors of malignant disease and Fuhrman grade.

RESULTS

A total of 253 patients had malignant masses, while 64 had benign masses. A total of 189 of the malignant masses were T1a, while 64 were designated T1b. A total of 221 patients with malignant masses had reported Fuhrman grades. Of these 211 patients, 143 (64.7%) had low-grade and 78 (35.3%) had high-grade disease. Mean PFA was 18.0 ± 13.3 cm², while mean MAP score was 2.6 ± 1.2. Binary logistic regression analysis yielded three variables in the best-fit model for predictors of malignant pathology: MAP score (OR = 1.374, 95% CI: 1.007-1.873, P = 0.045), male sex (OR = 2.058, 95% CI: 1.004-4.218, P = 0.049), and BMI (OR = 1.064, 95% CI: 0.998-1.135, P = 0.059). Neither MAP nor PFA was predictive of Fuhrman grade.

CONCLUSIONS

MAP score, a measure of perinephric fat quality, but not PFA, a qualitative measure of fat quantity, was predictive of malignant pathology, raising the question whether fat quality rather than quantity may be involved in the pathophysiology of RCC in a large and diverse patient population. Understanding the increasing burden of obesity, further studies are needed to elaborate on these findings and to discern the exact relationship between perinephric fat deposits and renal tumorigenesis.

Does total testicular volume predict testicular volume difference in adolescent males with varicocele?

Introduction:

We evaluated the relationship between total testicular volume (TTV) and testicular volume differential (TVD) in adolescent males with varicocele. Both low TTV and high TVD have been independently associated with higher incidences of infertility later in life, but a predictive relationship between TTV and TVD directly has yet to be described.

Materials and Methods:

We retrospectively analyzed a database of Tanner 5 boys ages 16-21 who presented with varicocele at a single institution between 2009 and 2017. All patients had a scrotal sonogram prior to surgical intervention. TTV and TVD were calculated for each individual and four non-exclusive groupings of patients were created for statistical analysis. We chose 30 cc as a cut off value for low TTV based on prior studies.

Results:

209 patients met our inclusion criteria. Mean age was 18.3 years (16–21, SD 1.7) with a mean total testicular volume of 36 cc (13.5-78.2, SD 11.1). Cut off points of TVD of 20% and TTV of 30 cc were used to separate patients. There were 65 boys (31%) with TTV < 30 cc and 58 boys (28%) with TVD ≥ 20%. Among males with TTV < 30 cc, 23 (35%) had a TVD ≥ 20%. Among males with TTV ≥ 30 cc, 35 (24%) had a TVD ≥ 20%. The relationship between TVD and TTV was found to be non-significant (p > 0.05).

Discussion:

Adolescent varicoceles continue to pose a challenge to pediatric urologists. The dilemma of over-aggressive treatment has proven difficult to balance with the risk of infertility. We hoped that elucidating the relationship between TTV and TVD could be useful in identifying patients who are at greater risk for infertility while decreasing the need for more intrusive testing, such as semen analysis, in an adolescent population. We looked at the direct relationship between low TTV and high TVD. In our population, there was a non-significant relationship between TTV < 30 cc and TVD ≥ 20% (p > 0.05) indicating that in adolescents with varicocele, TTV and TVD are independent variables. Our study limitations include the inherent user dependent bias of ultrasound measurements and data collection at a single institution with high ethnic diversity, possibly not comparable to all patient populations.

Conclusions:

Low TTV (< 30 cc) itself is not predictive of high TVD (≥ 20%) in adolescent boys with varicocele, despite their reported independent associations with impaired fertility in other studies.