Thomas J. Schnoeller

Enzalutamide in castration-resistant prostate cancer patients progressing after docetaxel and abiraterone.

BACKGROUND Abiraterone, an androgen synthesis inhibitor, has been successfully used in the treatment of castration-resistant prostate cancer (CRPC) for 2 yr. Enzalutamide is a second-generation nonsteroidal antiandrogen that has recently been approved for the same indication. OBJECTIVE This is the first study to evaluate the effectiveness of enzalutamide after failure of abiraterone. DESIGN, SETTING, AND PARTICIPANTS Thirty-five patients were identified as having received sequential therapy with abiraterone followed by enzalutamide. All patients had undergone prior docetaxel chemotherapy, and no patient had received ketoconazole. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Posttreatment changes in prostate-specific antigen (PSA) were used to determine the activity of enzalutamide in patients who had received prior abiraterone. RESULTS AND LIMITATIONS The median duration of abiraterone treatment was 9.0 mo (range: 2.0-19.0 mo). Of the 35 patients, 16 (45.7%) achieved a >50% decline in PSA, and 14 (40%) had a rising PSA as the best response. The median duration of subsequent enzalutamide treatment was 4.9 mo (Kaplan-Meier estimate; 95% confidence interval [CI], 2.4-7.4). Seven of 16 CRPC patients who were initially abiraterone-sensitive (43.8%) and 3 of 19 CRPC patients who were initially abiraterone-insensitive (15.8%) showed a >50% PSA decline while taking enzalutamide. Of the 35 patients, 17 (48.6%) were primarily enzalutamide-resistant and showed a rising PSA as the best response. Median time to progression was 4.0 mo (95% CI, 2.0-6.0) for 18 of 35 patients with at least one declining PSA value while taking enzalutamide (51.4%). Of the 17 patients who were assessable radiologically, only 1 (2.9%) attained a confirmed partial response. Small sample size was the major limitation. CONCLUSIONS Enzalutamide treatment achieved only a modest response rate in patients progressing after abiraterone. Although cross-resistance between abiraterone and enzalutamide was a common phenomenon, it was not inevitable, and a small but significant number of patients showed significant benefit from sequential treatment.

Detecting predictive androgen receptor modifications in circulating prostate cancer cells

Molecular modifications of the androgen receptor (AR) can cause resistance to androgen deprivation therapy (ADT) in prostate cancer patients. Since lack of representative tumor samples hinders therapy adjustments according to emerging AR-modifications, we evaluated simultaneous detection of the two most common AR modifications (AR-V7 splice variant and AR point mutations) in circulating tumor cells (CTCs). We devised a single-tube assay to detect AR-V7 splice variants and AR point mutations in CTCs using immunomagnetic cell isolation, followed by quantitative real-time PCR and DNA pyrosequencing. We prospectively investigated 47 patients with PSA progression awaiting therapy switch. Comparison of response to newly administered therapy and CTC-AR-status allowed effect size estimation. Nineteen (51%) of 37 patients with detectable CTCs carried AR-modifications. Seventeen patients carried the AR-V7 splice variant, one harbored a p.T878A point mutation and one harbored both AR-V7 and a p.H875Y mutation. We estimated a positive predictive value for response and non-response to therapy by AR status in CTCs of ~94%. Based on a conservative calculation, we estimated the effect size for molecularly-informed therapy switches for prospective clinical trial planning to ~27%. In summary, the ability to determine key resistance-mediating AR modifications in CTCs has the potential to considerably improve prostate cancer treatment.

Upper Urinary Tract Recurrence After Radical Cystectomy for Bladder Cancer—Who is at Risk?

PURPOSE Patients who underwent radical cystectomy for bladder cancer are at risk for upper urinary tract recurrence. We identified subgroups of patients at increased risk for upper urinary tract recurrence. MATERIALS AND METHODS All 1,420 patients who underwent radical cystectomy for bladder cancer at our center between January 1986 and October 2008 were included in the study. Negative frozen sections of the ureteral margins were obtained from all patients. Data analysis included preoperative tumor history, pathological findings of the cystectomy specimen and complete followup. Survival was calculated using the Kaplan-Meier method. RESULTS Until October 2008, 25 cases of upper urinary tract recurrence were observed. The overall rate of upper urinary tract recurrence at 5, 10 and 15 years was 2.4%, 3.9% and 4.9%, respectively. Of the patients 3 had superficial tumors of the renal pelvis and 22 had invasive upper tract transitional cell carcinoma. Upper urinary tract recurrence did not develop in any patients with nontransitional cell carcinoma. Four risk factors for upper urinary tract recurrence were identified including history of carcinoma in situ (RR 2.3), history of recurrent bladder cancer (RR 2.6), cystectomy for nonmuscle invasive bladder cancer (RR 3.8) and tumor involvement of the distal ureter in the cystectomy specimen (RR 2.7). Patients with transitional cell carcinoma who had none of these risk factors had an upper urinary tract recurrence rate of only 0.8% at 15 years. This rate increased with the number of positive risk factors, ie 8.4% in patients with 1 to 2 risk factors and 13.5% in those with 3 to 4 risk factors. CONCLUSIONS Patients who underwent cystectomy for transitional cell carcinoma and with at least 1 risk factor for upper urinary tract recurrence should have closer followup regimens than those with nontransitional cell carcinoma or without any of these risk factors.

Expression of AR-V7 in Circulating Tumour Cells Does Not Preclude Response to Next Generation Androgen Deprivation Therapy in Patients with Castration Resistant Prostate Cancer

The androgen receptor splice variant AR-V7 has recently been discussed as a predictive biomarker for nonresponse to next-generation androgen deprivation therapy (ADT) in patients with castration-resistant prostate cancer. However, we recently identified one patient showing a response from abiraterone despite expression of AR-V7 in his circulating tumour cells (CTC). Therefore, we precisely assessed the response in a cohort of 21 AR-V7 positive castration-resistant prostate cancer patients who had received therapy with abiraterone or enzalutamide. We detected a subgroup of six AR-V7 positive patients showing benefit from either abiraterone or enzalutamide. Their progression free survival was 26 d (censored) to 188 d. Four patients displayed a prostate-specific antigen decrease of >50%. When analysing prior therapies, we noticed that only one of the six patients had received next-generation ADT prior to CTC collection. As a result, we conclude that AR-V7 status in CTC cannot entirely predict nonresponse to next generation ADT and AR-V7-positive patients should not be systematically denied abiraterone or enzalutamide treatment, especially as effective alternative treatment options are still limited. PATIENT SUMMARY A subgroup of patients can benefit from abiraterone and/or enzalutamide despite detection of AR-V7 splice variants in their circulating tumour cells.

High CRP values predict poor survival in patients with penile cancer

BackgroundHigh levels of circulating C-reactive protein (CRP) have recently been linked to poor clinical outcome in various malignancies. The aim of this study was to evaluate the prognostic significance of the preoperative serum CRP level in patients with squamous cell carcinoma (SCC) of the penis.MethodsThis retrospective analysis included 79 penile cancer patients with information about their serum CRP value prior to surgery who underwent either radical or partial penectomy at two German high-volume centers (Ulm University Medical Center and Hannover Medical School) between 1990 and 2010. They had a median (mean) follow-up of 23 (32) months.ResultsA significantly elevated CRP level (>15 vs. ≤ 15 mg/l) was found more often in patients with an advanced tumor stage (≥pT2) (38.9 vs. 11.6%, p=0.007) and in those with nodal disease at diagnosis (50.0 vs. 14.6%, p=0.007). However, high CRP levels were not associated with tumor differentiation (p=0.53). The Kaplan-Meier 5-year cancer-specific survival (CSS) rate was 38.9% for patients with preoperative CRP levels above 15 mg/l and 84.3% for those with lower levels (p=0.001). Applying multivariate analysis and focusing on the subgroup of patients without metastasis at the time of penile surgery, both advanced local tumor stage (≥pT2; HR 8.8, p=0.041) and an elevated CRP value (>15 mg/l; HR 3.3, p=0.043) were identified as independent predictors of poor clinical outcome in patients with penile cancer.ConclusionsA high preoperative serum CRP level was associated with poor survival in patients with penile cancer. If larger patient populations confirm its prognostic value, its routine use could enable better risk stratification and risk-adjusted follow-up of patients with SCC of the penis.

Neoadjuvant therapy of renal cell carcinoma: a novel treatment option in the era of targeted therapy?

The study was carried out to evaluate the effectiveness, toxicity and optimal duration of neoadjuvant therapy for patients with organ‐confined or locally advanced renal cell carcinoma in the era of targeted agents. A literature review was carried out using Medline/Pubmed articles, as well as congress reports from the last five American Society of Clinical Oncology, American Urological Association and European Association of Urology Annual Meetings. Neoadjuvant targeted therapy is feasible and shows toxicity similar to that seen in a palliative setting. Most studies recommend an application for 2–4 months. The current data situation is best for sunitinib. Surgery can apparently be carried out the day right after discontinuing the drug. However, even sunitinib leads to only a mean 10% decrease in primary tumor size, and one‐quarter to one‐fifth of all patients show local tumor progression during treatment. Few patients (approximately 12%) with a vena cava tumor thrombus achieve a significant decrease in its level under neoadjuvant therapy; here too, progression is observed in a significant number of cases. Even the new targeted agents show limited effectiveness in achieving relevant remissions of the primary tumor. Furthermore, tumor progression is seen in a significant percentage of patients during neoadjuvant therapy. Thus, even today in the era of targeted agents, a neoadjuvant approach should only be made in patients with localized or locally advanced renal cell carcinoma, which primarily seem to be absolutely inaccessible by (partial) nephrectomy.

The role of histologic subtype, p16INK4a expression, and presence of human papillomavirus DNA in penile squamous cell carcinoma

BackgroundUp to 50% of penile squamous cell carcinomas (pSCC) develop in the context of high-risk human papillomavirus (HR-HPV) infection. Most of these tumours have been reported to show basaloid differentiation and overexpression of tumour suppressor protein p16INK4a. Whether HPV-triggered carcinogenesis in pSCC has an impact on tumour aggressiveness, however, is still subject to research.MethodsIn tissue specimens from 58 patients with surgically treated pSCC between 1995 and 2012, we performed p16INK4a immunohistochemistry and DNA extraction followed by HPV subtyping using a PCR-based approach. The results were correlated with histopathological and clinical parameters.Results90.4% of tumours were of conventional (keratinizing) subtype. HR-HPV DNA was detected in 29.3%, and a variety of p16INK4a staining patterns was observed in 58.6% of samples regardless of histologic subtype. Sensitivity of basaloid subtype to predict HR-HPV positivity was poor (11.8%). In contrast, sensitivity and specificity of p16INK4a staining to predict presence of HR-HPV DNA was 100% and 57%, respectively. By focussing on those samples with intense nuclear staining pattern for p16INK4a, specificity could be improved to 83%. Both expression of p16INK4a and presence of HR-HPV DNA, but not histologic grade, were inversely associated with pSCC tumour invasion (p = 0.01, p = 0.03, and p = 0.71). However, none of these correlated with nodal involvement or distant metastasis. In contrast to pathological tumour stage, the HR-HPV status, histologic grade, and p16INK4a positivity failed to predict cancer-specific survival.ConclusionsOur results confirm intense nuclear positivity for p16INK4a, rather than histologic subtype, as a good predictor for presence of HR-HPV DNA in pSCC. HR-HPV / p16INK4a positivity, independent of histological tumour grade, indicates a less aggressive local behaviour; however, its value as an independent prognostic indicator remains to be determined. Since local invasion can be judged without p16INK4a/HPV-detection on microscopic evaluation, our study argues against routine testing in the setting of pSCC.

Partial nephrectomy using porcine small intestinal submucosa

BackgroundWhenever technically feasible and oncologically justified, nephron-sparing surgery is the current standard of care for localized renal cell carcinomas (RCC). The main complications of partial nephrectomy, especially for large and centrally located tumors, are urinary leakage and parenchymal bleeding. We prospectively evaluated the pros and cons of using porcine small intestinal submucosa (SIS, Surgisis®) to close the renal defect after nephron-sparing surgery.MethodsWe used Surgisis® (Cook medical, Bloomington, IN, USA) to secure and compress the capsular defect after tumor resection in 123 patients submitted to 129 partial nephrectomies between August 2003 and February 2011.ResultsThe median tumor size was 3.7 cm (range 1.1-13.0 cm). Procedures were performed with cold ischemia in 24 cases (18.2%), with warm ischemia in 46 (35.6%), and without ischemia in 59 cases (44.8%). In the total group of patients, 4 (3.1%) developed urinary fistula, and only 2 (1.6%) required postoperative transfusions due to hemorrhage after the application of the small intestinal submucosa membrane.ConclusionSmall intestinal submucosa is an easy-to-use biomaterial for preventing complications such as postoperative bleeding and urinary fistula in nephron-sparing surgery, especially in cases where tumor excision causes significant renal capsular and/or renal pelvic defects.

Corpulence is the crucial factor: association of testosterone and/or obesity with prostate cancer stage.

To evaluate whether low testosterone levels or obesity, or both, are directly associated with tumor stage/grade in patients with clinically localized prostate cancer.

Influence of serum cholesterol level and statin treatment on prostate cancer aggressiveness

Both cholesterol levels and the use of statins have been described to influence the development and prognosis of prostate cancer (PC). In this retrospective, cross-sectional analysis of consecutive cases from a tertiary referral center we evaluated an association between hypercholesterolemia (≥5.0mmol/l), the use of statins, and advanced/aggressive PC in 767 men with histologically confirmed, clinically localized PC awaiting radical prostatectomy. We found that patients with HCE (n=287, 37.4%) had a significantly higher incidence of poorly differentiated PC (Gleason score ≥7b, 81.1% vs. 4.9%), advanced local tumor stage (≥pT3, 57.7% vs. 22.2%), and nodal involvement (19.8% vs. 1.6%). Multivariate logistic regression analysis identified hypercholesterolemia as a risk factor for aggressive and/or advanced PC (OR 2.01, p<0.001) whereas statin intake showed an odds ratio of 0.49 (p=0.005) indicating a negative association with high-risk PC. Despite a limited number of patients using statins (~9.5%), adjusted and weighed multivariate logistic regression models revealed that preoperative hypercholesterolemia is associated with a diagnosis of high-risk PC which is negatively influenced by statin intake.