Impact of obesity on outcomes after definitive dose escalated intensity modulated radiation therapy for localized prostate cancer

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Background: Multiple retrospective studies have investigated the association between body mass index (BMI) and biochemical failure (BF) after definitive external beam radiotherapy (EBRT) of localized prostate cancer (CaP) prior to the dose escalation era, with conflicting results. The purpose of this study is to determine whether increasing BMI is associated with CaP outcomes in patients treated with dose escalated radiotherapy. Methods: From 2000 to 2010, we identified 1,291 patients with localized (T1b-T4N0M0) CaP who were treated with definitive intensity modulated radiation therapy (IMRT). BMI was categorized using World Health Organization classification. Multivariable competing risk and Cox proportional hazards regression models were used to assess the risk of BF, distant metastasis (DM), cause-specific mortality (CSM) and overall mortality (OM). BF was defined as prostate-specific antigen (PSA) greater than or equal to nadir + 2 ng/mL. Covariates included age, androgen deprivation therapy (ADT), pre-treatment PSA (iPSA), Gleason score, and T stage. For OM, self-reported history of diabetes, heart disease, and hypertension were included. Results: Of the 1,291 patients identified, there were 20% normal (BMI<25 kg/m2), 47% overweight (BMI 25-29.9), 23% obese class I (BMI 30-34.9), 6% obese class II (BMI 35-39.9), and 4% obese class III (BMI >40). Median follow-up was 43.7 months (range 1.1-127) with median age of 68 (range 36 to 88). Median dose was 78 Gy (range 76-80) and 33% of patients received ADT. Increasing BMI was inversely associated with age (p<0.0001) and iPSA (p=0.047). There were 128 BF, 51 DM, 15 CSM, and 119 OM. Risk of BF, CSM, and OM were increased for obese class II and III compared to normal (all p<0.05). On multivariable analysis, for BF, HR was 2.1(p=0.057) for obese class II and 2.5 (p=0.043) for class III. For CSM, HR was 5.1 (p=0 .028) for class II and 5.15 (p=0.014) for class III. For OM, HR was 2.3 (p=0.022) for class II and 2.6(p=0.023) for class III. There was a trend toward increased DM for class III (p=0.057). Conclusions: For CaP patients receiving IMRT, those with higher levels of obesity may be at increased risk of BF and prostate cancer mortality, and should be considered for more aggressive treatment.

Association of tumor size with metastatic potential and survival in patients with adrenocortical carcinoma: an analysis of the National Cancer Database

INTRODUCTION

To assess the impact of size at presentation in patients with adrenocortical carcinoma (ACC) on rates of synchronous metastatic disease and survival following resection using a large administrative dataset.

MATERIALS AND METHODS

We queried the National Cancer Database (NCDB) dataset to assemble a cohort of patients with ACC based on SEER staging (1985-2000). Patients were stratified into three groups based on surgical tumor size cutoffs: < 4 cm, 4 cm-6 cm, and > 6 cm. Rates of metastatic disease at presentation in all ACC patients as well as relative survival for patients after resection of localized lesions were calculated and compared among groups.

RESULTS

A total of 2248 patients had available staging information for analysis. Tumor size at presentation did not relate to likelihood of non-localized disease at presentation (p = 0.09). A restricted cubic splines analysis revealed a clinically insignificant relationship between tumor size and advanced disease at presentation (OR = 1.02 for each centimeter change in tumor size, p = 0.004, 95% CI 1.01-1.03). On multivariate analysis, only patient age (p < 0.01), and not tumor size, was a significant predictor of overall survival among patients undergoing resection of localized ACCs.

CONCLUSIONS

Our data suggest that tumor size is imperfect in predicting presence of distant disease at presentation, nor does it consistently correlate with patient survival after resection of localized ACC.

Coexisting hybrid malignancy in a solitary sporadic solid benign renal mass: implications for treating patients following renal biopsy

PURPOSE

Concern regarding coexisting malignant pathology in benign renal tumors deters renal biopsy and questions its validity. We examined the rates of coexisting malignant and high grade pathology in resected benign solid solitary renal tumors.

MATERIALS AND METHODS

Using our prospectively maintained database we identified 1,829 patients with a solitary solid renal tumor who underwent surgical resection between 1994 and 2012. Lesions containing elements of renal oncocytoma, angiomyolipoma or another benign pathology formed the basis for this analysis. Patients with an oncocytic malignancy without classic oncocytoma and those with known hereditary syndromes were excluded from study.

RESULTS

We identified 147 patients with pathologically proven elements of renal oncocytoma (96), angiomyolipoma (44) or another solid benign pathology (7). Median tumor size was 3.0 cm (IQR 2.2-4.5). As quantified by the R.E.N.A.L. (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior and location relative to polar lines) nephrometry score, tumor anatomical complexity was low in 28% of cases, moderate in 56% and high in 16%. Only 4 patients (2.7%) were documented as having hybrid malignant pathology, all involving chromophobe renal cell carcinoma in the setting of renal oncocytoma. At a median followup of 44 months (IQR 33-55) no patient with a hybrid tumor experienced regional or metastatic progression.

CONCLUSIONS

In our cohort of patients with a solitary, sporadic, solid benign renal mass fewer than 3% of tumors showed coexisting hybrid malignancy. Importantly, no patient harbored coexisting high grade pathology. These data suggest that uncertainty regarding hybrid malignant pathology coexisting with benign pathological components should not deter renal biopsy, especially in the elderly and comorbid populations.

Comparison of prostate cancer diagnosis in patients receiving unrelated urological and non-urological cancer care

OBJECTIVE

To evaluate prostate cancer diagnosis rates and survival outcomes in patients receiving unrelated (non-prostate) urological care with those in patients receiving non-urological care.

MATERIALS AND METHODS

We conducted a population-based study using the Surveillance Epidemiology and End Results (SEER) database to identify men who underwent surgical treatment of renal cell carcinoma (RCC; n = 18,188) and colorectal carcinoma (CRC; n = 45,093) between 1992 and 2008. Using SEER*stat software to estimate standardized incidence ratios (SIRs), we investigated rates of prostate cancer diagnosis in patients with RCC and patients with CRC. Adjusting for patient age, race and year of diagnosis on multivariate analysis, we used Cox and Fine and Gray proportional hazards regressions to evaluate overall and disease-specific survival endpoints.

RESULTS

The observed incidence of prostate cancer was higher in both the patients with RCC and those with CRC: SIR = 1.36 (95% confidence interval [CI] 1.27-1.46) vs 1.06 (95% CI 1.02-1.11). Adjusted prostate cancer SIRs were 30% higher (P < 0.001) in patients with RCC. Overall (hazard ratio = 1.13, P < 0.001) and primary cancer-adjusted mortalities (sub-distribution Hazard Ratio (sHR) = 1.17, P < 0.001) were higher in patients with RCC with no significant difference in prostate cancer-specific mortality (sHR = 0.827, P = 0.391).

CONCLUSION

Rates of prostate cancer diagnosis were higher in patients with RCC (a cohort with unrelated urological cancer care) than in those with CRC. Despite higher overall mortality in patients with RCC, prostate cancer-specific survival was similar in both groups. Opportunities may exist to better target prostate cancer screening in patients who receive non-prostate-related urological care. Furthermore, urologists should not feel obligated to perform prostate-specific antigen screening for all patients receiving non-prostate-related urological care.

Is there a benefit to frozen section analysis at the time of partial nephrectomy?

INTRODUCTION

The utility of frozen section performance during partial nephrectomy (PN) is controversial. We assessed the predictive value of frozen sections on final margin status for patients undergoing PN for localized renal tumors.

MATERIALS AND METHODS

We queried our prospectively maintained kidney cancer database for patients undergoing PN with localized renal tumors from 2005-2011. Patients were stratified based on the receipt of frozen section analysis into 'frozen' and 'no frozen' groups. Groups were compared using ANOVA, Chi-square, and Wilcoxon's tests.

RESULTS

A total of 537 patients (mean age 58.1 years ± 12.0 years, 64.2% male) underwent PN (mean tumor size 3.7 cm ± 2.0 cm; mean Nephrometry score 7.5 ± 1.8) from 2005-2011. Comparing tumor characteristics between patients undergoing frozen sections (83.1%) and those who did not (16.9%), no differences in histology, Fuhrman grade, pathologic stage, or Nephrometry Score were observed between groups. Final margins were positive in 10 patients (11.0%) in the 'no frozen' group compared to 20 patients (4.5%) in the 'frozen' section group (p = 0.01) but in patients with a documented malignancy on final pathology, final margins were positive in 5.5% and 2.9% respectively (p = 0.16). Four patients (0.7%) had local recurrences, all of whom had negative frozen and final pathologic margins. There was no correlation between positive surgical margins and local recurrence (p = 1.0) at a median follow up of 21 months (IQR = 9-31months).

CONCLUSIONS

In our institutional cohort, frozen section analysis failed to impact final margin status in patients with documented renal cell carcinoma. Given the oncologic uncertainty of positive surgical margins, further prospective evaluation is necessary to determine the clinical utility of frozen section analysis.

Clinical characteristics associated with treatment type for localized renal tumors: implications for practice pattern assessment

OBJECTIVE

To determine the associations between the pretreatment characteristics and treatment selection in patients presenting with clinical stage I renal masses.

MATERIALS AND METHODS

Using institutional data, patients presenting with clinical stage I (≤ 7 cm) renal tumors that were managed with active surveillance (AS), tumor ablation (ABL), partial nephrectomy (PN), or radical nephrectomy (RN) from 2005 to 2011 were identified. The associations between the pretreatment characteristics and the selected treatment strategy were assessed using multinomial regression models, with RN as the reference group.

RESULTS

A total of 969 patients (mean age 61.9 ± 12.8 years) with 1034 clinical stage I lesions (mean tumor size 3.3 ± 1.5 cm) met the inclusion criteria. The patients were initially treated with RN (29.4%), PN (38.8%), ABL (6.1%), and AS (25.7%). Traditionally captured covariates, including older age (PN, odds ratio [OR] 0.96, 95% confidence interval [CI] 0.94-0.99]) and decreasing tumor size (PN, OR 0.2, 95% CI 0.1-0.4; ABL, OR 0.01, 95% CI 0.0-0.1; AS, OR 0.2, 95% CI 0.1-0.3) were associated with alternative treatment types compared with RN. However, the characteristics associated with treatment type that are not included in traditional registry or administrative data included the presence of a solitary kidney (PN, OR 11.9, 95% CI 2.9-48.9; ABL, OR 15.5, 95% CI 2.5-98.1; AS, OR 7.1, 95% CI 1.3-39.3) and high complexity nephrectomy score (PN, OR 0.1, 95% CI 0.1-0.3; ABL, OR 0.1, 95% CI 0.0-0.6; AS, OR 0.1, 95% CI 0.03-0.3).

CONCLUSION

Pretreatment characteristics associated with treatment type in our series, including the presence of a solitary kidney and anatomic complexity, are poorly captured using administrative and registry data. Observational studies investigating the variations in practice patterns for stage I renal masses require improved integration of clinical and tumor characteristics to reduce selection biases.

Zinc and zinc transporters in prostate carcinogenesis

The healthy human prostate accumulates the highest level of zinc of any soft tissue in the body. This unique property is retained in BPH, but is lost in prostatic malignancy, which implicates changes in zinc and its transporters in carcinogenesis. Indeed, zinc concentrations diminish early in the course of prostate carcinogenesis, preceding histopathological changes, and continue to decline during progression toward castration-resistant disease. Numerous studies suggest that increased zinc intake might protect against progression of prostatic malignancy. In spite of increased dietary intake, zinc accumulation might be limited by the diminished expression of zinc uptake transporters, resulting in decreased intratumoural zinc levels. This finding can explain the conflicting results of various epidemiological studies evaluating the role of zinc supplementation on primary and secondary prostate cancer prevention. Overall, more research into the mechanisms of zinc homeostasis are needed to fully understand its impact on prostate carcinogenesis. Only then can the potential of zinc and zinc transport proteins be harnessed in the diagnosis and treatment of men with prostate cancer.

Use of biopsy detail to identify subgroup risk in high-risk patients with prostate cancer

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Background: High Risk (HR) prostate cancer (CaP) patients (pts) are a heterogeneous group. A recursive partitioning analysis (RPA) was performed to determine if tissue involvement could identify patients at risk for biochemical failure (BF). Methods: Between 1992-2009, 608 HR CaP pts with complete prostate biopsy detail data (% overall tissue involvement (%TI), GP45 (weighted average of %TI for Gleason Pattern 4 or 5), Gleason Score (GS)) underwent RT with/out ADT. Primary endpoint was freedom from biochemical failure (FFBF). RPA based on time to BF was used to determine cutpoints for each prognostic variable. Multivariable (MVA) RPAs were used to assess interactions of significant variables (p<0.05) from univariate analysis (UVA). Results: Median follow up for PSA measurement was 45 months (3-193 mo). UVA RPA revealed significant cutpoints for FFBF for Tstage (higher risk of BF(HRBF) for T2c,T3b,T3c,T4,Tx vs lower risk of BF(LRBF) for T1,T2a,T2b,T3a, (p<0.001)); GS(HRBF 3+4/5, 4+5 vs LRBF 2-6, 2+3/4, 5+3/4/5 (p=0.011); iPSA (LRBF ≤37 vs HRBF >37 ng/ml (p<0.001)); dose (HRBF ≤74.9 vs LRBF >74.9 Gy); RT type(LRBF IMRT vs HRBF 3D-CRT, p=0.032), %TI (LRBF ≤53% vs HRBF >53% (p<0.001)); GP45 (LRBF ≤33% vs HRBF >33%(p<0.001)). Overall, FFBF at 5 yr was 79.2% (95%CI 75.0-82.8). For MVA RPA, splits are same as UVA unless noted. MVA RPA excluding GP45 and %TI showed 5 groups (5 yr FFBF 45.9%, 66.8%, 74.2%, 84.2% and 89.5%; N 16, 195, 69, 20 and 308, respectively). Tstage, iPSA, GS and RT type had significant interactions, with highest risk group including PSA >44ng/ml, low Tstage and 3D-CRT, and lowest risk group including PSA ≤44 ng/ml, lower risk Tstage, and lower risk GS. Including %TI in the RPA, significant interactions were between %TI (2 splits), iPSA and GS (5 yr FFBF 50.0%, 62.5%, 71.9%, 80.4% and 92.7%; N 80, 24, 65, 233, and 206, respectively). Highest risk group included pts with %TI >53%; lowest risk included pts with %TI <17%, iPSA <40 ng/mL, and GS lower risk. Using GP45 instead of %TI, 3 groups were found: high GP45; low GP45 and iPSA ≥40; low GP45 and iPSA<40 ng/ml, (5 yr FFBF 58.9%, 67.7% and 85.5%; N 103, 63 and 442, respectively). Conclusions: Pts with > 53% TI, > 33% GP45 and iPSA > 40 ng/ml are at highest risk of failure, and should be considered for most aggressive treatment.

Association of hospital readmission following cystectomy with omission of postoperative chemotherapy in patients with urothelial carcinoma of the bladder

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Background: Hypothesizing that complications after radical cystectomy requiring hospital re-admission may preclude subsequent systemic treatment, our objective was to test the association between readmission within 30 days of surgery and receipt of post-operative chemotherapy in Medicare beneficiaries. Methods: Using 1995-2007 linked Surveillance, Epidemiology, and End Results (SEER)-Medicare data, all patients undergoing cystectomy for pathologic stage III-IV urothelial carcinoma were identified. Univariate and multivariate logistic regression analyses were used to test the association between hospital readmission within 30 days and receipt of post-operative chemotherapy (defined ≤9 months from surgery) adjusting for demographic, clinical, hospital, and procedural characteristics. Results: We identified 4,034 patients undergoing radical cystectomy for urothelial carcinoma, of which 1,498 met final inclusion criteria (mean age 75.9±6.3 years, 62.7% male). 563 patients (37.6%) were readmitted within 30 days of surgery (7.5% with ≥2 readmissions). Postoperative chemotherapy was administered in 26.1% of candidates who were readmitted, compared to 35.4% who were not readmitted following surgery (p<0.001). Following adjustment, the odds of receiving chemotherapy were 30% less in patients readmitted to the hospital (OR 0.70 [CI 0.53-0.92]) when compared to patients who were not readmitted. Stratified by number of readmissions, the odds of receiving chemotherapy in patients with 1 and ≥2 readmissions were 26% (OR 0.74 [CI 0.56-0.99]) and 54% (OR 0.46 [CI 0.27-0.79]) less when compared to patients not readmitted. Use of a more restrictive 6 month post operative chemotherapy definition did not significantly impact our findings (OR 0.66 [CI 0.47-0.93]). Conclusions: In a cohort of Medicare beneficiaries undergoing cystectomy, hospital readmission within 30 days is associated with omission of post-operative chemotherapy in patients with Stage III-IV urothelial carcinoma. These data inform treatment planning decisions and strengthen the argument supporting chemotherapy utilization in the neoadjuvant setting.

Piperlongumine induces rapid depletion of the androgen receptor in human prostate cancer cells

BACKGROUND

Androgen receptor (AR) signaling is regarded as the driving force in prostate carcinogenesis, and its modulation represents a logical target for prostate cancer (PC) prevention and treatment. Natural products are the most consistent source of small molecules for drug development. In this study, we investigate the functional impact of piperlongumine (PL), a naturally occurring alkaloid present in the Long pepper (Piper longum), on AR expression in PC cells and delineate its mechanism of action.

METHODS

Expression and transcriptional activity of AR was examined by western blotting and luciferase reporter assay, respectively. CellTiter Blue assay was utilized to quantify cell proliferation. Reactive oxygen species (ROS) generation was examined by staining cells with a ROS indicator CM-H(2) DCFDA, followed by flow cytometry analysis.

RESULTS

The results of our experiments demonstrate that PL rapidly reduces AR protein levels in PC cells via proteasome-mediated ROS-dependent mechanism. Moreover, PL effectively depletes a modified AR lacking the ligand-binding domain, shedding light on a new paradigm in the treatment approach to prostatic carcinoma that expresses mutated constitutively active AR. Importantly, PL effectively depletes AR in PC cells at low micromolar concentrations, while concurrently exerting a significant inhibitory effect on AR transcriptional activity and proliferation of PC cells.

CONCLUSIONS

Our investigation demonstrates for the first time that PL induces rapid depletion of the AR in PC cells. As such, PL may afford novel opportunities for both prevention and treatment of prostatic malignancy.

Evaluating prostate cancer mortality and competing risks of death in patients with localized prostate cancer using a comprehensive nomogram

BACKGROUND

The aim of this study was to determine the optimal treatment for a patient with newly diagnosed prostate cancer weighing the individual's risk of disease progression against his risk of non-cancer death.

METHODS

We developed a predictive model incorporating clinicopathological tumor variables, patient age, comorbidity status, and primary treatment modality. We identified 6091 patients with clinically-localized prostate cancer managed with radical prostatectomy (n=4117) or radiation therapy (n=1974) from the Cancer of the Prostate Strategic Urologic Research Endeavor database. Fine and Gray competing-risks proportional hazards regression models were used to calculate the risks of prostate cancer-specific mortality (PCSM) and non-prostate cancer death and to generate a nomogram.

RESULTS

The median follow-up after treatment was 53 months (interquartile range 30, 80 months). In total, 983 men died during follow-up, including 167 who died of prostate cancer and 816 who died of non-prostate cancer causes. On multivariate analysis, higher Cancer of the Prostate Risk Assessment score and primary treatment with radiation were associated with an increased risk of PCSM, whereas older age, African-American race, and treatment with radiation predicted non-prostate cancer death. The number of comorbidities and receipt of androgen deprivation therapy correlated with an increased risk of non-prostate cancer death, but not PCSM. The resulting nomogram allows quantification and comparison of the 10-year risk of PCSM and non-prostate cancer death.

CONCLUSIONS

Integrating clinicopathological variables with comorbid conditions in a competing-risks model affords quantification and comparison of relative probabilities of PCSM and non-prostate cancer death following treatment. Our model thereby facilitates an individualized approach for counseling patients regarding prostate cancer management.

Prolonged natural progression from localized to symptomatic renal cell carcinoma

Surgical excision is the gold standard therapy for clinically localized renal masses. Nevertheless, prognostication of the natural history of untreated renal cell carcinoma (RCC) remains a clinical challenge. While active surveillance (AS) has emerged as a viable treatment option in select patients with localized tumors and significant competing mortality risks, long term follow up data to assess the risk of disease progression are limited. We present a case of a localized, clinical stage T2 renal mass progressing to regional and systemic disease over 6 years, demonstrating that kinetics of disease progression may be prolonged and are yet to be fully understood.

Does partial nephrectomy result in a durable overall survival benefit in the Medicare population?

PURPOSE

We assessed whether the impact of partial nephrectomy and radical nephrectomy on overall mortality differed by patient age in a Medicare population undergoing surgery for T1a renal cell carcinoma.

MATERIALS AND METHODS

Using linked SEER (Surveillance, Epidemiology and End Results)-Medicare data, we identified patients older than 66 years who underwent partial nephrectomy or radical nephrectomy for T1a (4 cm or smaller) renal cell carcinoma from 1995 to 2007. The effects of procedure type on overall mortality by age were assessed using time dependent Cox proportional hazards models adjusted by propensity score based weighting.

RESULTS

A total of 5,496 patients (mean age 74.2 ± 5.6 years, 55.9% male) who underwent partial nephrectomy (1,665; 30.3%) or radical nephrectomy (3,831; 69.7%) for 4 cm or smaller renal cell carcinoma (mean tumor size 2.8 ± 0.9 cm) were identified. After adjustment, a statistically significant survival benefit for partial nephrectomy compared to radical nephrectomy was observed at 1 year (age 68, HR 1.6, CI 1.2-2.3; age 75, HR 1.5, CI 1.1-1.9; age 85, HR 1.7, CI 1.1-2.5) and 3 years (age 68, HR 1.4, CI 1.03-2.0; age 75, HR 1.3, CI 1.1-1.6; age 85, HR 1.5, CI 1.02-2.3), while these trends became insignificant in patients younger than 68 and older than 85 years. However, the survival benefit decreased with time, and little significant benefit with partial nephrectomy was observed at 5 and 10 years after surgery regardless of age (66 years or older).

CONCLUSIONS

Lacking strong evidence regarding a long-term survival benefit, the decision to perform partial nephrectomy in elderly patients should be individualized, and placed in the context of baseline renal function, expected surgical morbidity and competing risks to survival.

Pathological concordance and surgical outcomes of sporadic synchronous unilateral multifocal renal masses treated with partial nephrectomy

PURPOSE

Patients with unilateral synchronous multifocal renal masses represent a unique population with renal cell carcinoma. While pathological concordance rates have been studied for bilateral cases, limited data exist on unilateral multifocal disease. We characterized pathological concordance rates in this population and evaluated the outcomes of nephron preservation.

MATERIALS AND METHODS

Patients who underwent surgery from 2000 to 2012 for unilateral synchronous multifocal renal masses were identified from a prospectively maintained database. Demographic, surgical and pathological outcomes of this cohort were analyzed. Malignant concordance rates were defined as agreement of all malignant tumor types in a single renal unit. Histological concordance was defined as agreement of all resected mass histologies, eg all clear cell carcinomas. Nuclear grade was considered concordant if all tumors excised were low (Fuhrman 1 or 2, type 1) or high (Fuhrman 3 or 4, type 2) grade.

RESULTS

Using our institutional database of 2,569 patients with renal tumors we identified 97 with unilateral synchronous multifocal renal masses. Malignant and benign concordance rates were 77.2% and 48.6%, and histological and grade concordance rates were 58.8% and 51.5%, respectively. In this cohort we identified 76 patients (76.3% male) with a median age of 62.5 years who had a total of 241 unilateral synchronous multifocal renal masses and underwent nephron sparing surgery. Median mass size was 2.0 cm (IQR 1.1-3.1), there was a median of 3 tumors per patient and median followup was 24 months (IQR 13-40). Identified renal cell carcinoma histologies included clear cell in 49.4% of cases, papillary in 33.5%, mixed in 4.5% and chromophobe in 2.8%.

CONCLUSIONS

In what is to our knowledge the largest published report of unilateral synchronous multifocal renal masses we document low pathological concordance rates. As such, percutaneous biopsy of a single renal mass in these patients may not help inform treatment decisions. Nephron sparing surgery may be performed with acceptable oncological and functional results in patients with unilateral synchronous multifocal renal masses.

Economic burden of repeat renal surgery on solitary kidney--do the ends justify the means? A cost analysis

PURPOSE

Despite the high morbidity of repeat renal surgery in patients with multifocal recurrent renal carcinoma, in most patients adequate renal function is preserved to obviate the need for dialysis. To our knowledge the economic burden of repeat renal surgery has not been evaluated. We provide a cost analysis for patients requiring repeat renal surgery on a solitary kidney.

MATERIALS AND METHODS

We reviewed the charts of patients treated at the National Cancer Institute who required repeat renal surgery from 1989 to 2010. Functional, oncological and surgical outcomes were evaluated and the costs of repeat renal surgery were calculated. We then compared costs in a cohort of 33 patients who underwent repeat renal surgery on a solitary kidney and in a hypothetical patient cohort treated with uncomplicated nephrectomy, fistula placement and dialysis. All costs were calculated based on Medicare reimbursement rates derived from CPT codes. Cost analysis was performed.

RESULTS

Despite a high 45% complication rate, 87% of patients maintained renal function that was adequate to avoid dialysis and 96% remained metastasis free at an average followup of 3.12 years (range 0.3 to 16.4). Compared to the hypothetical dialysis cohort, the financial benefit of repeat renal surgery was reached at 0.68 years.

CONCLUSIONS

Repeat renal surgery is a viable alternative for patients with multifocal renal cell carcinoma requiring multiple surgical interventions, especially when left with a solitary kidney. Despite the high complication rate, renal function is preserved in most patients and they have an excellent oncological outcome. The financial benefit of repeat renal surgery is reached at less than 1 year.

Competing risks of death in patients with localized renal cell carcinoma: a comorbidity based model

PURPOSE

Multiple risks compete with cancer as the primary cause of death. These factors must be considered against the benefits of treatment. We constructed a model of competing causes of death to help contextualize treatment trade-off analyses in patients with localized renal cell carcinoma.

MATERIALS AND METHODS

We identified 6,655 individuals 66 years old or older with localized renal cell carcinoma in the linked SEER (Surveillance, Epidemiology and End Results)-Medicare data set for 1995 to 2005. We used Fine and Gray competing risks proportional hazards regression to predict probabilities of competing mortality outcomes. Prognostic markers included race, gender, tumor size, age and the Charlson comorbidity index score.

RESULTS

At a median followup of 43 months, age and comorbidity score strongly correlated with patient mortality and were most predictive of nonkidney cancer death, as measured by concordance statistics. Patients with localized, node negative kidney cancer had a low 3 (4.7%), 5 (7.5%) and 10-year (11.9%) probability of cancer specific death but a significantly higher overall risk of death from competing causes within 3 (10.9%), 5 (20.1%) and 10 years (44.4%) of renal cell carcinoma diagnosis, depending on comorbidity score.

CONCLUSIONS

Informed treatment decisions regarding patients with solid tumors must integrate not only cancer related variables but also factors that predict noncancer death. We established a comorbidity based predictive model that may assist in patient counseling by allowing quantification and comparison of competing risks of death in patients 66 years old or older with localized renal cell carcinoma who elect to proceed with surgery.

Role of tumor location in selecting patients for percutaneous versus surgical cryoablation of renal masses

INTRODUCTION

To characterize the relationship between tumor location and choice in selecting surgical cryoablation (SCA) versus percutaneous cryoablation (PCA) for treatment of renal masses.

MATERIALS AND METHODS

MEDLINE search was performed to identify studies in which cryoablation was used as therapy for renal masses. Tumor location was stratified as anterior, posterior, or lateral. Lesions were also described by endophycity (endo-, meso-, or exophytic) and polarity (upper, mid, or lower pole). Treating specialty was stratified as urology, radiology, or both. Comorbidity reporting rates were indexed for each manuscript.

RESULTS

Thirty-seven manuscripts included 2344 lesions treated by SCA or PCA formed the basis for the analysis. Comparing SCA versus PCA series, anterior/posterior designation was reported in 31% versus 47% of series; endophycity designation was reported in 17% versus 40% of series; and polarity designation was reported in 48% versus 47% of series (all p values > 0.05). Amongst those lesions treated by SCA, 44% were anterior lesions and 28% were posterior, while among PCA-treated lesions 9% were anterior and 81% were posterior. Tumor location description was entirely absent in 32% (14/44) of published series.

CONCLUSIONS

Despite data that tumor location is integral to choice of treatment for renal mass, anatomic tumor descriptors are vastly underreported in the cryotherapy literature. Nearly one third of masses treated with SCA are on the posterior surface of the affected kidney, and may be amenable to PCA, thus avoiding risk of general anesthesia and intraabdominal dissection in comorbid cohorts. Better reporting of objective measures of tumor anatomy and location in cryosurgery literature may facilitate standardization of treatment protocols in patients with renal mass.

The effect of 5-aminolevulinic acid and its derivatives on protoporphyrin IX accumulation and apoptotic cell death in castrate-resistant prostate cancer cells

OBJECTIVE

To examine whether pharmacologically relevant zinc-binding agents are capable of depleting X-linked inhibitor of apoptosis protein in tumor cells. Our prior work reveals that treatment with zinc-chelating agents induces selective downregulation of the X-linked inhibitor of apoptosis protein in cancer cells of various origins. A precursor of the heme synthetic pathway, 5-aminolevulinic acid, is metabolized to protoporphyrin IX, which is highly reactive with zinc. We assessed whether modified versions of 5-aminolevulinic acid with lipophilic side chains can enhance efficacy and selectivity with respect to protoporphyrin IX accumulation, X-linked inhibitor of apoptosis protein depletion, and tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis in human castration-resistant prostate cancer cells.

METHODS

Seven modified versions of 5-aminolevulinic acid (5 esters and 2 amides) were synthesized. Levels of endogenous protoporphyrin IX were examined by flow cytometry. X-linked inhibitor of apoptosis protein expression was examined by Western blotting. terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay was used to assess cell apoptosis. Results were compared qualitatively.

RESULTS

Accumulation of endogenous protoporphyrin IX by castration-resistant prostate cancer cells was shown to be directly related to the carbon chain length of the esterified 5-aminolevulinic acid derivatives. In fact, treatment with 5-aminolevulinic acid-HE was superior to that achieved by 5-aminolevulinic acid with respect to X-linked inhibitor of apoptosis protein downregulation. 5-aminolevulinic acid and 5-aminolevulinic acid-HE in combination with tumor necrosis factor-related apoptosis-inducing ligand significantly enhanced apoptotic cell death in castration-resistant prostate cancer cell lines.

CONCLUSION

Esterified derivatives of 5-aminolevulinic acid alone or in combination with other agents may provide therapeutic opportunities in the treatment of castration-resistant prostate cancer by harnessing apoptotic pathways that are triggered by cellular zinc imbalance.

Enhancing renal tumors in patients with prior normal abdominal imaging: further insight into the natural history of renal cell carcinoma

PURPOSE

Patients undergoing serial cross-sectional abdominal imaging to evaluate abdominal symptomatology may have a renal tumor develop during followup of an unrelated disease process. Evaluation of such patients provides an opportunity to further define the radiographic inception, natural history and growth patterns of renal tumors.

MATERIALS AND METHODS

Renal tumor databases from 2 institutions were reviewed for patients in whom an enhancing renal tumor developed despite a prior normal cross-sectional radiographic examination of the kidneys. Variables evaluated included age, gender, tumor size at presentation, calculated tumor growth rate from negative scan to radiographic presentation and pathology in patients undergoing definitive treatment.

RESULTS

We identified 36 patients with an average age of 65 years (range 44 to 82). Mean tumor size on presentation was 2.3 cm (range 1.0 to 5.0). The presumed absolute growth rate based on the timing of the initial negative imaging study and tumor diameter at presentation was significantly greater than the observed absolute growth rate after tumor detection (0.71 vs 0.039 cm per year, p = 0.028). No difference was noted between presumed and observed tumor growth based on absolute change in tumor volume (1.44 vs 5.37 cm(3) per year, p = 0.203). Presumed relative growth rates based on tumor diameter (665% vs 23% per year) and volume (1,397% vs 169% per year) were significantly greater than observed relative growth rates (p = 0.005 and p = 0.013, respectively).

CONCLUSIONS

The presumed growth rate of the tumors was significantly greater than the observed growth rate, suggesting that tumor growth rates do not follow a linear pattern throughout their development and progression.

Assessing performance trends in laparoscopic nephrectomy and nephron-sparing surgery for localized renal tumors

OBJECTIVE

To assess the impact of laparoscopy on usage of partial nephrectomy (PN) by comparing national usage trends in patients undergoing surgery for localized renal tumors.

METHODS

Using linked Surveillance, Epidemiology, and End Results (SEER)-Medicare data, we retrospectively examined trends in procedure usage from 1995 to 2007 for patients undergoing surgery for localized (stage I/II) renal masses. Procedures were classified as open radical nephrectomy (ORN), laparoscopic radical nephrectomy (LRN), open partial nephrectomy (OPN), and laparoscopic partial nephrectomy (LPN). Patients were further stratified by tumor size (≤4 cm, >4- ≤7 cm, >7 cm). Data were primarily analyzed using logistic regressions.

RESULTS

Patients (n = 11,689, mean age 74.4 ± 5.7 years, 56% male) with a mean tumor size of 4.7 ± 3.3 cm met the inclusion criteria. From 1995 to 2007, ORN rates decreased and for each year successive year patients were more likely to be treated with OPN (odds ratio [OR] 1.17, 95% confidence interval [CI] 1.14-1.19), LRN (OR 1.44, CI 1.41-1.47), and LPN (OR 1.75, CI 1.68-1.83). Although the increased usage of OPN (7.5% vs 13.6%, P < .001) and LPN (0% vs 14.2%, P < .001) reached statistical significance, this was offset by a marked increase in LRN over the same time period (3.0% vs 43.0%, P < .001).

CONCLUSION

Despite increasing emphasis on nephron preservation, PN usage rates remain low. Compared with a 40% increase in LRN, use of PN increased by only 20% from 1995 to 2007. As a result, 72% of identified Medicare beneficiaries with localized tumors were managed with radical nephrectomy (RN) in 2007. The trade-off of minimally invasive surgery for nephron preservation may have adverse long-term consequences.

Neoadjuvant accelerated MVAC (AMVAC) in patients with muscle invasive bladder cancer: Results of a multicenter phase II study

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Background: Standard methotrexate, vinblastine, doxorubicin and cisplatin (MVAC) demonstrates a survival benefit in the neoadjuvant setting for patients (pts) with muscle invasive bladder cancer (MIBC). Compared with standard MVAC, AMVAC yielded higher response rates with less toxicity in the metastatic setting. Methods: Pts with MIBC, cT2-T4a, and N0-N1 with CrCl >=50 and adequate hepatic and marrow function were eligible. Pts received 3 cycles of AMVAC (methotrexate 30 mg/m2, vinblastine 3 mg/m2, doxorubicin 30 mg/m2, cisplatin 70mg/m2) on day 1, with pegfilgrastim 6 mg day 2 or 3, every 2 weeks. Pts with CrCl < 60 could receive cisplatin split over 2 days. Radical cystectomy (RC) with lymph node dissection was performed 4-8 weeks after the last dose of chemotherapy. Primary endpoint was pathologic complete response (pCR) rate. Results: Accrual is complete with 44 MIBC pts enrolled at 2 institutions (FCCC, TJU) over a 25 month period. Median age 64 (range 45-83). Three withdrew from study early and are not evaluable for response (2 physician discretion, 1 withdrawal of consent). An additional 8 are currently receiving treatment on study with toxicity and response data pending. Of the 33 evaluable pts for whom final data is available, 30 received all 3 cycles of AMVAC at full dose. Three pts received < 3 cycles due to grade 3 fatigue (1), low platelets (1), and disease progression precluding RC (1). 32/33 pts underwent RC, all within 8 weeks of last chemotherapy. Median time from start of chemotherapy to RC was 9.7 wks (range 4.6-13 wks). 13/33 pts (39.4%, 95% CI, 22.7-56.1%) had a pCR. An additional 3 (9.1%) were downstaged to non muscle invasive disease. For the intent to treat cohort (n=36) 8 pts had grade 3-4 AMVAC related adverse events, the most common being anemia (3), fatigue (3) and neutropenia (2) and overall pCR rate was 36.1%. (95% CI, 20.4-51.8%). All pts will have completed study treatment by April 2012. Final results will be presented. Conclusions: Neoadjuvant AMVAC is well tolerated and preliminary results show a pCR rate similar to that reported for standard 12-week MVAC, suggesting that AMVAC for three cycles (6 weeks) is a safe and efficient alternative.

Co-administration of piperine and docetaxel results in improved anti-tumor efficacy via inhibition of CYP3A4 activity

BACKGROUND

Docetaxel is the mainline treatment approved by the FDA for castration-resistant prostate cancer (CRPC) yet its administration only increases median survival by 2-4 months. Docetaxel is metabolized in the liver by hepatic CYP3A4 activity. Piperine, a major plant alkaloid/amide, has been shown to inhibit the CYP3A4 enzymatic activity in a cell-free system. Thus, we investigated whether the co-administration of piperine and docetaxel could increase docetaxel's pharmacokinetic activity in vitro and in vivo.

METHODS

Liver CYP3A4 enzymatic activity was measured by fluorescence. In vivo docetaxel pharmacokinetic activity was analyzed by liquid chromatography. An in vivo xenograft model of human CRPC was utilized to assess the anti-tumor effect of docetaxel when co-administered with piperine.

RESULTS

Inhibition of hepatic CYP3A4 activity resulted in an increased area under the curve, half-life and maximum plasma concentration of docetaxel when compared to docetaxel alone administration. The synergistic administration of piperine and docetaxel significantly improved the anti-tumor efficacy of docetaxel in a xenograft model of human CRPC.

CONCLUSIONS

Docetaxel is one of the most widely used cytotoxic chemotherapeutic agents and is currently the mainstay treatment for metastatic CRPC. Dietary constituents are important agents modifying drug metabolism and transport. In our studies, dietary consumption of piperine increases the therapeutic efficacy of docetaxel in a xenograft model without inducing more adverse effects on the treated mice.

Modulation of Akt/mTOR signaling overcomes sunitinib resistance in renal and prostate cancer cells

Tyrosine kinase inhibitors exhibit impressive activity against advanced renal cell carcinoma. However, recent clinical studies have shown an equivocal response to sunitinib in patients with castration-resistant prostate cancer. The tumor suppressor PTEN acts as a gatekeeper of the phosphoinositide 3-kinase (PI3K)/Akt/mTOR cell-survival pathway. Our experiments showed that PTEN expression inversely correlates with sunitinib resistance in renal and prostate cancer cells. Restoration of PTEN expression markedly increases sensitivity of tumor cells to sunitinib both in vitro and in vivo. In addition, pharmacologic manipulation of PI3K/Akt/mTOR signaling with PI3K/mTOR inhibitor, GDC-0980, mTOR inhibitor, temsirolimus, or pan-Akt inhibitor, GSK690693, was able to overcome sunitinib resistance in cancer cells. Our findings underscore the importance of PTEN expression in relation to sunitinib resistance and imply a direct cytotoxic effect by sunitinib on tumor cells in addition to its antiangiogenic actions.

Perioperative outcomes of robotic and open partial nephrectomy for moderately and highly complex renal lesions

PURPOSE

We compared outcomes in patients undergoing robotic vs open partial nephrectomy stratified by moderately and highly complex tumor nephrometry scores.

MATERIALS AND METHODS

Patients treated with partial nephrectomy from 2007 to 2010 were grouped by tumor characteristics into low-nephrotomy score 4 to 6, moderate-7 to 9 and high-10 to 12 anatomical complexity cohorts. Lesions with low complexity were excluded from study. Demographic, surgical and pathological outcomes were compared between patients undergoing robotic vs open partial nephrectomy in the moderately and highly complex cohorts.

RESULTS

A total of 281 patients, of whom 63.3% were male, with a mean±SD age of 58.1±11.7 years and a mean followup of 21.3±16.3 months underwent partial nephrectomy. Moderately complex lesions were noted in 81 robotic and 136 open partial nephrectomy cases with a mean tumor size of 3.8±2.2 cm. Highly complex lesions were noted in 10 robotic and 54 open partial nephrectomy cases with a mean tumor size of 4.8±3.0 cm. There were no differences between the groups in patient age, race, gender, body mass index or American Society of Anesthesiologists classification. Cases treated with open partial nephrectomy for moderately or highly complex lesions were of higher pathological stage (p=0.02 and 0.01, respectively). The percent change in creatinine and the glomerular filtration rate were similar for robotic and open partial nephrectomy in the moderately and highly complex tumor groups. In patients undergoing robotic vs open partial nephrectomy for moderately complex lesions we noted differences in pathological tumor size (mean 3.2±1.8 vs 4.1±2.3 cm, p<0.0001) and operative time (205.9±52.5 vs 189.5±52.0 minutes, p<0.01) while decreased estimated blood loss (131.3±127.8 vs 256.5±291.3 ml) and hospital length of stay (3.7±1.6 vs 5.6±3.9 days, each p<0.001) were observed in the robotic group. Comparison of highly complex lesions revealed decreased hospital length of stay (2.9±1.4 vs 6.1±4.1 days, p<0.0001) in the robotic partial nephrectomy group.

CONCLUSIONS

In our large institutional series of patients with moderate and highly complex solid renal tumors classified by the nephrometry score robotic partial nephrectomy offered comparable perioperative and functional outcomes with the added benefit of decreased hospital length of stay.

Prostate bed motion during intensity-modulated radiotherapy treatment

PURPOSE

Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders.

METHODS AND MATERIALS

The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center.

RESULTS

At localization, prostate bed displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course.

CONCLUSION

Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.