Combined RAF and MEK Inhibition to Treat Activated Non-V600 BRAF-Altered Advanced Cancers.

BACKGROUND: Cancers with non-V600 BRAF-activating alterations have no matched therapy. Preclinical data suggest that these tumors depend on ERK signaling; however, clinical response to MEK/ERK inhibitors has overall been low. We hypothesized that a narrow therapeutic index, driven by ERK inhibition in healthy (wild-type) tissues, limits the efficacy of these inhibitors. As these mutants signal as activated dimers, we further hypothesized that RAF inhibitors given concurrently would improve the therapeutic index by opposing ERK inhibition in normal tissues and not activate ERK in the already activated tumor. MATERIALS AND METHODS: Using cell lines and patient-derived xenografts, we evaluated the effect of RAF inhibition, alone and in combination with MEK/ERK inhibitors. We then undertook a phase I/II clinical trial of a higher dose of the MEK inhibitor binimetinib combined with the RAF inhibitor encorafenib in patients with advanced cancer with activating non-V600 BRAF alterations. RESULTS: RAF inhibition led to modest inhibition of signaling and growth in activated non-V600 BRAF preclinical models and allowed higher dose of MEK/ERK inhibitors in vivo for more profound tumor regression. Fifteen patients received binimetinib 60 mg twice daily plus encorafenib 450 mg daily (6 gastrointestinal primaries, 6 genitourinary primaries, 3 melanoma, and 2 lung cancer; 7 BRAF mutations and 8 BRAF fusions). Treatment was well tolerated without dose-limiting toxicities. One patient had a confirmed partial response, 8 had stable disease, and 6 had radiographic or clinical progression as best response. On-treatment biopsies revealed incomplete ERK pathway inhibition. CONCLUSION: Combined RAF and MEK inhibition does not sufficiently inhibit activated non-V600 BRAF-mutant tumors in patients.

Sorafenib in Dupuytren and Ledderhose Disease.

Palmar and plantar fibromatosis are benign proliferative processes which present as a diffuse thickening or nodules of the hands and/or feet and may lead to flexion contractures, pain, and functional impairment known as Dupuytren and Ledderhose diseases, respectively. Current treatments are noncurative and associated with significant morbidity. Here, we report on the outcomes of 5 patients with advanced disease, no longer surgical candidates, treated with sorafenib. Sorafenib exhibited an expected safety profile. All 5 patients demonstrated objective responses as evaluated by a decrease in tumor size and/or tumor cellularity from baseline and all 5 patients reported subjective pain relief and/or functional improvement. Mechanistically, immunohistochemistry revealed patchy positivity for PDGFRß, a known target of sorafenib. The outcomes of these 5 patients suggest the safety and efficacy of a relatively well-tolerated oral agent in the treatment of Dupuytren and Ledderhose diseases and suggest the need for future controlled studies.

Local Extent of Prostate Cancer at MRI versus Prostatectomy Histopathology: Associations with Long-term Oncologic Outcomes.

Background It is unknown how the imperfect accuracy of MRI for local staging of prostate cancer relates to oncologic outcomes. Purpose To analyze how staging discordances between MRI and histopathologic evaluation relate to recurrence and survival after radical prostatectomy. Materials and Methods Health Insurance Portability and Accountability Act-compliant retrospective analysis of preprostatectomy T2-weighted prostate MRI (January 2001 to December 2006). Extraprostatic extension and seminal vesicle invasion were assessed by using five-point Likert scales; scores of 4 or higher were classified as positive. Biochemical recurrence (BCR), metastases, and prostate cancer-specific mortality rates were estimated with Kaplan-Meier and Cox models. Results A total of 2160 patients (median age, 60 years; interquartile range, 55-64 years) were evaluated. Among patients with histopathologic extraprostatic (pT3) disease (683 of 2160; 32%), those with organ-confined disease at MRI (384 of 683; 56%) experienced better outcomes than those with concordant extraprostatic disease at MRI and pathologic analysis: 15-year risk for BCR, 30% (95% CI: 22, 40) versus 68% (95% CI: 60, 75); risk for metastases, 14% (95% CI: 8.4, 24) versus 32% (95% CI: 26, 39); risk for prostate cancer-specific mortality, 3% (95% CI: 1, 6) versus 15% (95% CI: 9.5, 23) (P < .001 for all comparisons). Among patients with histopathologic organ-confined disease (pT2) (1477 of 2160; 68%), those with extraprostatic disease at MRI (102 of 1477; 7%) were at higher risk for BCR (27% [95% CI: 19, 37] vs 10% [95% CI: 8, 14]; P < .001), metastases (19% [95% CI: 6, 48] vs 3% [95% CI: 1, 6]; P < .001), and prostate cancer-specific mortality (2% [95% CI: 1, 9] vs 1% [95% CI: 0, 5]; P = .009) than those with concordant organ-confined disease at MRI and pathologic analysis. At multivariable analyses, tumor extent at MRI (hazard ratio range, 4.1-5.2) and histopathologic evaluation (hazard ratio range, 3.6-6.7) was associated with the risk for BCR, metastases, and prostate cancer-specific mortality (P < .001 for all analyses). Conclusion The local extent of prostate cancer at MRI is associated with oncologic outcomes after prostatectomy, independent of pathologic tumor stage. This might inform a strategy on how to integrate MRI into a clinical staging algorithm. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Gottlieb in this issue.

Sorafenib for Advanced and Refractory Desmoid Tumors.

BACKGROUND: Desmoid tumors (also referred to as aggressive fibromatosis) are connective tissue neoplasms that can arise in any anatomical location and infiltrate the mesentery, neurovascular structures, and visceral organs. There is no standard of care. METHODS: In this double-blind, phase 3 trial, we randomly assigned 87 patients with progressive, symptomatic, or recurrent desmoid tumors to receive either sorafenib (400-mg tablet once daily) or matching placebo. Crossover to the sorafenib group was permitted for patients in the placebo group who had disease progression. The primary end point was investigator-assessed progression-free survival; rates of objective response and adverse events were also evaluated. RESULTS: With a median follow-up of 27.2 months, the 2-year progression-free survival rate was 81% (95% confidence interval [CI], 69 to 96) in the sorafenib group and 36% (95% CI, 22 to 57) in the placebo group (hazard ratio for progression or death, 0.13; 95% CI, 0.05 to 0.31; P<0.001). Before crossover, the objective response rate was 33% (95% CI, 20 to 48) in the sorafenib group and 20% (95% CI, 8 to 38) in the placebo group. The median time to an objective response among patients who had a response was 9.6 months (interquartile range, 6.6 to 16.7) in the sorafenib group and 13.3 months (interquartile range, 11.2 to 31.1) in the placebo group. The objective responses are ongoing. Among patients who received sorafenib, the most frequently reported adverse events were grade 1 or 2 events of rash (73%), fatigue (67%), hypertension (55%), and diarrhea (51%). CONCLUSIONS: Among patients with progressive, refractory, or symptomatic desmoid tumors, sorafenib significantly prolonged progression-free survival and induced durable responses. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT02066181 .).

Oncologic Outcomes after Localized Prostate Cancer Treatment: Associations with Pretreatment Prostate Magnetic Resonance Imaging Findings.

PURPOSE: We investigated whether T2-weighted magnetic resonance imaging findings could improve upon established prognostic indicators of metastatic disease and prostate cancer specific survival. MATERIALS AND METHODS: For a cohort of 3,406 consecutive men who underwent prostate magnetic resonance imaging before prostatectomy (2,160) or radiotherapy (1,246) between 2001 and 2006, T2-weighted magnetic resonance imaging exams were retrospectively interpreted and categorized as I) no focal suspicious lesion, II) organ confined focal lesion, III) focal lesion with extraprostatic extension or IV) focal lesion with seminal vesicle invasion. Clinical risk was recorded based on European Association of Urology (EAU) guidelines and the Cancer of the Prostate Risk Assessment (CAPRA) scoring system. Survival probabilities and c-indices were estimated using Cox models and inverse probability censoring weights, respectively. RESULTS: The median followup was 10.8 years (IQR 8.6-13.0). Higher magnetic resonance imaging categories were associated with a higher likelihood of developing metastases (HR 3.5-18.1, p <0.001 for all magnetic resonance imaging categories) and prostate cancer death (HR 3.1-29.7, p <0.001-0.025); these associations were statistically independent of EAU risk categories, CAPRA scores and treatment type (surgery vs radiation). Combining EAU risk or CAPRA scores with magnetic resonance imaging categories significantly improved prognostication of metastases (c-indices: EAU: 0.798, EAU + magnetic resonance imaging: 0.872; CAPRA: 0.808, CAPRA + magnetic resonance imaging: 0.877) and prostate cancer death (c-indices: EAU 0.813, EAU + magnetic resonance imaging: 0.889; CAPRA: 0.814, CAPRA + magnetic resonance imaging: 0.892; p <0.001 for all). CONCLUSION: Magnetic resonance imaging findings of localized prostate cancer are associated with clinically relevant long-term oncologic outcomes. Combining magnetic resonance imaging and clinicopathological data results in more accurate prognostication, which could facilitate individualized patient management.

Spindle Cell Lipoma Revisited: Common and Unusual Magnetic Resonance Imaging Findings in 54 Patients With New Observations.

ABSTRACT: The aims of the study were to study demographic data of patients with spindle cell lipoma and describe a spectrum of magnetic resonance imaging features of the tumor.

Association of MRI T2 Signal Intensity With Desmoid Tumor Progression During Active Observation: A Retrospective Cohort Study.

OBJECTIVE: The aim of this study was to identify predictors of desmoid progression during observation. SUMMARY OF BACKGROUND DATA: Untreated desmoids can grow, remain stable, or regress, but reliable predictors of behavior have not been identified. METHODS: Primary or recurrent desmoid patients were identified retrospectively from an institutional database. In those managed with active observation who underwent serial magnetic resonance imaging (MRIs) with T2-weighted sequences, baseline tumor size was recorded, and 2 radiologists independently estimated the percentage of tumor volume showing hyperintense T2 signal at baseline. Associations of clinical or radiographic characteristics with progression-free survival (PFS; by RECIST) were evaluated by Cox regression and Kaplan-Meier statistics. RESULTS: Among 160 patients with desmoids, 72 were managed with observation, and 37 of these had serial MRI available for review. Among these 37 patients, median age was 35 years and median tumor size was 4.7 cm; all tumors were extra-abdominal (41% in abdominal wall). Although PFS was not associated with size, site, or age, it was strongly associated with hyperintense T2 signal in ≥90% versus <90% of baseline tumor volume (as defined by the "test" radiologist; hazard ratio = 11.3, P = 0.003). For patients in the ≥90% group (n = 20), 1-year PFS was 55%, compared with 94% in the <90% group (n = 17). The percentage of baseline tumor volume with hyperintense T2 signal defined by a validation radiologist correlated with results of the test radiologist (ρ = 0.75). CONCLUSION: The percent tumor volume characterized by hyperintense T2 signal is associated with desmoid progression during observation and may help distinguish patients who would benefit from early intervention from those who may be reliably observed.

A Phase II Trial of Sorafenib and Dacarbazine for Leiomyosarcoma, Synovial Sarcoma, and Malignant Peripheral Nerve Sheath Tumors.

BACKGROUND: Sorafenib and dacarbazine have low single-agent response rates in metastatic sarcomas. As angiogenesis inhibitors can enhance the efficacy of chemotherapy, we investigated the combination of sorafenib and dacarbazine in select sarcoma subtypes. MATERIALS AND METHODS: Patients with leiomyosarcoma (LMS), synovial sarcoma (SS), or malignant peripheral nerve sheath tumors (MPNST) with up to two previous lines of therapy and adequate hepatic, renal, and marrow function received 3-week cycles of sorafenib at 400 mg oral twice daily and dacarbazine 1,000 mg/m2 intravenously (later reduced to 850 mg/m2). Patients were evaluated for response every 6 weeks. The primary objective was to determine the disease control rate (DCR) of sorafenib plus dacarbazine in the selected sarcoma subtypes. RESULTS: The study included 37 patients (19 female); median age was 55 years (range 26-87); and histologies included LMS (22), SS (11), and MPNST (4). The DCR was 46% (17/37). Median progression-free survival was 13.4 weeks. The RECIST response rate was 14% (5/37). The Choi response rate was 51% (19/37). Median overall survival was 13.2 months. Of the first 25 patients, 15 (60%) required dacarbazine dose reductions for hematologic toxicity, with one episode of grade 5 neutropenic fever. After reducing the starting dose of dacarbazine to 850 mg/m2, only 3 of the final 12 (25%) patients required dose reduction. CONCLUSION: This phase II study met its primary endpoint with an 18-week DCR of 46%. The clinical activity of dacarbazine plus sorafenib in patients with these diagnoses is modest. IMPLICATIONS FOR PRACTICE: Metastatic soft tissue sarcomas are a heterogeneous group of relatively rare malignancies. Most patients are treated with cytotoxic chemotherapy or targeted therapy in the form of tyrosine kinase inhibitors. Response rates are relatively low, and there is a need for better therapies. This clinical trial demonstrates that combining a cytotoxic therapy (dacarbazine) with an antiangiogenic small molecule (sorafenib) is feasible and associated with favorable disease-control rates; however, it also increases the potential for significant toxicity.

Myxoinflammatory Fibroblastic Sarcoma: Clinical, Imaging, Management and Outcome in 29 Patients.

OBJECTIVE: This retrospective study was undertaken to highlight clinical and magnetic resonance imaging features of myxoinflammatory fibroblastic sarcoma. METHODS: The clinical records of 29 patients (14 men and 15 women) were analyzed. RESULTS: The soft tissue tumors involved hand, wrist, foot and ankle in 21 patients, more proximal extremities in 7 patients, and neck in 1 patient. The tumors were subcutaneous in 11 patients, and intramuscular in 15 patients. On magnetic resonance imaging, these tumors had nonspecific features suggestive of benign and malignant lesions. An unusual tumor in hand indicated infection, whereas an intraarticular knee tumor mimicked pigmented villonodular synovitis. All tumors were surgically resected. CONCLUSIONS: Myxoinflammatory fibroblastic sarcoma, a rare low-grade subcutaneous soft tissue tumor of distal extremities with high local recurrence after resection can mimic several benign and malignant lesions on histopathology and imaging. Rarely, it can arise in muscles and tendons, occur in nonacral sites, be aggressive, and even metastasize. In most cases, surgical resection with wide margins can be curative with low local recurrence.

89Zr-huJ591 immuno-PET imaging in patients with advanced metastatic prostate cancer.

PURPOSE: Given the bone tropism of prostate cancer, conventional imaging modalities poorly identify or quantify metastatic disease. (89)Zr-huJ591 positron emission tomography (PET) imaging was performed in patients with metastatic prostate cancer to analyze and validate this as an imaging biomarker for metastatic disease. The purpose of this initial study was to assess safety, biodistribution, normal organ dosimetry, and optimal imaging time post-injection for lesion detection. METHODS: Ten patients with metastatic prostate cancer received 5 mCi of (89)Zr-huJ591. Four whole-body scans with multiple whole-body count rate measurements and serum activity concentration measurements were obtained in all patients. Biodistribution, clearance, and lesion uptake by (89)Zr-huJ591 immuno-PET imaging was analyzed and dosimetry was estimated using MIRD techniques. Initial assessment of lesion targeting of (89)Zr-huJ591 was done. Optimal time for imaging post-injection was determined. RESULTS: The dose was well tolerated with mild chills and rigors seen in two patients. The clearance of (89)Zr-huJ591 from serum was bi-exponential with biological half-lives of 7 ± 4.5 h (range 1.1-14 h) and 62 ± 13 h (range 51-89 h) for initial rapid and later slow phase. Whole-body biological clearance was 219 ± 48 h (range 153-317 h). The mean whole-body and liver residence time was 78.7 and 25.6 h, respectively. Dosimetric estimates to critical organs included liver 7.7 ± 1.5 cGy/mCi, renal cortex 3.5 ± 0.4 cGy/mCi, and bone marrow 1.2 ± 0.2 cGy/mCi. Optimal time for patient imaging after injection was 7 ± 1 days. Lesion targeting of bone or soft tissue was seen in all patients. Biopsies were performed in 8 patients for a total 12 lesions, all of which were histologically confirmed as metastatic prostate cancer. One biopsy-proven lesion was not positive on (89)Zr-huJ591, while the remaining 11 lesions were (89)Zr-huJ591 positive. Two biopsy-positive nodal lesions were noted only on (89)Zr-huJ591 study, while the conventional imaging modality was negative. CONCLUSION: (89)Zr-huJ591 PET imaging of prostate-specific membrane antigen expression is safe and shows good localization of disease in prostate cancer patients. Liver is the critical organ for dosimetry, and 7 ± 1 days is the optimal imaging time. A larger study is underway to determine lesion detection in an expanded cohort of patients with metastatic prostate cancer.

Cabozantinib Plus Nivolumab in Patients with Non-Clear Cell Renal Cell Carcinoma: Updated Results from a Phase 2 Trial.

Treatment options are limited for patients with non-clear cell renal cell carcinoma (nccRCC). Patients with nccRCC experienced a favorable objective response rate (ORR) in a phase 2 trial of cabozantinib plus nivolumab. We now report updated efficacy and safety results at median follow-up of 34 mo for patients with papillary, unclassified, or translocation-associated RCC. Cabozantinib and nivolumab were administered at standard doses to patients with metastatic nccRCC that had progressed on zero or one line of systemic therapy. The primary endpoint was the ORR according to Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and adverse events. Forty patients were treated. At median follow-up of 34 mo for survivors, the ORR was 48% (95% confidence interval [CI] 31.5-63.9%). Median PFS was 13 mo (95% CI 7-16); the 12-mo and 24-mo PFS rates were 51% (95% CI 34-65%) and 23% (95% CI 11-37%), respectively. Median OS was 28 mo (95% CI 23-43); the 18-mo and 36-mo OS rates were 70% (95% CI 53-82%) and 44% (95% CI 28-60%), respectively. No new safety signals were seen with cabozantinib and nivolumab. This extended follow-up analysis demonstrates promising efficacy, and highlights the potential for sustained responses with cabozantinib plus nivolumab in patients with metastatic nccRCC.

Biopsy of suspicious bone lesions in patients with a single known malignancy: prevalence of a second malignancy.

OBJECTIVE: The probability that a suspicious bone lesion in a patient with one known malignancy is actually due to a second, previously unknown primary malignancy has been reported to be 2-8%. We sought to determine this prevalence as well as that of benign diagnoses in a larger number of patients in a tertiary cancer center. MATERIALS AND METHODS: The medical records of 482 consecutive patients (254 women and 228 men) with only one known primary malignancy each (excluding nonmelanoma skin cancer) and who underwent biopsy of a suspicious bone lesion were retrospectively reviewed. The results of bone biopsy were classified as benign, metastasis of the known primary malignancy, due to a second primary malignancy, or nondiagnostic or indeterminate. RESULTS: In 103 of 482 (21%) patients, bone biopsy results were benign, 316 (66%) were due to metastases of the known malignancy, 15 (3%) were due to a second malignancy, and 48 (10%) were nondiagnostic or indeterminate. Second malignancies included osteosarcoma (n = 4); soft-tissue sarcoma (n = 2); lymphoma (n = 2); plasma cell malignancy (n = 2); and lung cancer, thyroid cancer, renal cancer, chondrosarcoma, and carcinoma of unknown primary (n = 1 each). CONCLUSION: In 3% of patients with one known malignancy and a suspicious bone lesion, the lesion was due to a previously unknown second malignancy; in 21% of patients, the lesion was benign. Bone biopsy is recommended in the management of patients with one known cancer and a suspicious bone lesion only if the presence of a second malignancy would alter clinical management.

Myxofibrosarcoma: prevalence and diagnostic value of the "tail sign" on magnetic resonance imaging.

OBJECTIVE: Myxofibrosarcoma frequently shows curvilinear extensions of high T2 signal that also enhance on magnetic resonance imaging; these "tails" represent fascial extension of tumor at histopathological examination. This study was performed to determine whether the tail sign is helpful in distinguishing myxofibrosarcoma from other myxoid-containing neoplasms. MATERIALS AND METHODS: The study group consisted of 44 patients with pathologically proven myxofibrosarcoma; the control group consisted of 52 patients with a variety of other myxoid-predominant tumors. Three musculoskeletal radiologists independently evaluated T2-weighted (and/or short-tau inversion recovery) and post-contrast MR images for the presence of one or more enhancing, high-signal intensity, curvilinear projections from the primary mass. Sensitivity and specificity for the diagnosis of myxofibrosarcoma were calculated for each reader. Interobserver variability was assessed with kappa statistic and percentage agreement. RESULTS: A tail sign was deemed present in 28, 30, and 34 cases of myxofibrosarcoma and in 11, 9, and 5 of the controls for the three readers respectively, yielding a sensitivity of 64-77 % and a specificity of 79-90 %. The interobserver agreement was moderate-to-substantial (kappa=0.626). CONCLUSION: The tail sign at MRI is a moderately specific and sensitive sign for the diagnosis of myxofibrosarcoma relative to other myxoid-containing tumors.

Musculoskeletal tumors and tumor-like conditions: common and avoidable pitfalls at imaging in patients with known or suspected cancer: Part A: benign conditions that may mimic malignancy.

A wide range of musculoskeletal tumors and tumor-like conditions may be encountered when patients undergo radiological examinations. The imaging features of certain normal, reactive, benign neoplastic, inflammatory, traumatic, and degenerative processes in the musculoskeletal system may mimic malignant tumor; misinterpretation of the imaging findings can lead to inappropriate clinical management of the patient. This review describes and illustrates a number of such mimics that we have commonly encountered in our oncological imaging practice, and provides suggestions for avoiding each of these pitfalls. Because many orthopaedic surgeons interpret radiological images themselves, they need to be as aware as radiologists about these issues.

Musculoskeletal tumours and tumour-like conditions: common and avoidable pitfalls at imaging in patients with known or suspected cancer: Part B: malignant mimics of benign tumours.

A wide range of musculoskeletal tumours and tumour-like conditions may be encountered when patients undergo radiological examinations. Some malignant musculoskeletal lesions may mimic benign tumours at imaging, being confused with benign cystic lesions or haematomas. Also, inappropriately selected magnetic resonance (MR) image sequences or computed tomography (CT) display windows can lead to misdiagnosis. Many orthopaedic surgeons interpret radiological images themselves, and therefore need to be as aware of these issues as radiologists are. This review describes and illustrates a number of such errors that commonly occur, and provides suggestions for avoiding these pitfalls.

Renal cortical tumors: use of multiphasic contrast-enhanced MR imaging to differentiate benign and malignant histologic subtypes.

PURPOSE: To investigate the use of quantitative multiphasic contrast material-enhanced magnetic resonance (MR) imaging in differentiating between common benign and malignant histologic subtypes of renal cortical tumors. MATERIALS AND METHODS: The institutional review board waived informed consent and approved this retrospective HIPAA-compliant study of 138 patients who underwent preoperative contrast-enhanced MR imaging during the period of January 2004-December 2008. At surgery, 152 renal tumors were identified (77 clear cell, 22 papillary, 18 chromophobe, and 10 unclassified carcinomas; 16 oncocytomas; nine angiomyolipomas). Three readers independently identified and measured the most-enhanced area in each tumor and placed corresponding regions of interest in similar positions on images from the precontrast, corticomedullary, nephrographic, and excretory phases. The percentage change in signal intensity (%SI change) between precontrast imaging and each postcontrast phase was calculated. Interreader agreement was evaluated by using the overall concordance correlation coefficient (OCC). A linear mixed-effects model was used to estimate and compare the trajectories of the means of log %SI change across all phases between the six histologic subtypes. RESULTS: Interreader agreement was substantial to almost perfect (OCC, 0.77-0.88). The %SI change differed significantly between clear cell carcinomas and papillary and chromophobe carcinomas in all phases of enhancement (P < .0001-.0120). In addition, %SI change was significantly higher in angiomyolipomas than in clear cell carcinomas, but only in the corticomedullary phase (P = .0231). Enhancement did not differ significantly between clear cell carcinoma and oncocytoma in any phase (P = .2081-.6000). CONCLUSION: Quantitative multiphase contrast-enhanced MR imaging offers a widely available, reproducible method to characterize several histologic subtypes of renal cortical tumors, although it does not aid differentiation between clear cell carcinomas and oncocytomas.

MRI-Detectability of Clinically Significant Prostate Cancer Relates to Oncologic Outcomes After Prostatectomy.

INTRODUCTION/BACKGROUND: Magnetic resonance imaging (MRI) misses a proportion of "clinically significant" prostate cancers (csPC) as defined by histopathology criteria. The aim of this study was to analyze whether long-term oncologic outcomes differ between MRI-detectable and MRI-occult csPC. PATIENTS AND METHODS: Retrospective analysis of 1449 patients with pre-prostatectomy MRI and csPC on prostatectomy specimens (ie, Grade group ≥2 or extraprostatic spread) between 2001-2006. T2-weighted MRIs were classified according to the Prostate Imaging Reporting and Data System into MRI-occult (categories 1, 2), MRI-equivocal (category 3), and MRI-detectable (categories 4, 5). Cumulative incidence of biochemical recurrence (BCR), metastatic disease, and cancer-specific mortality, estimated with competing risk models. The median follow-up in survivors was 11.0 years (IQR: 8.9-13.1). RESULTS: In 188 (13%) cases, csPC was MRI-occult, 435 (30%) MRIs were equivocal, and 826 (57%) csPC were MRI-detectable. The 15-year cumulative incidence [95% CI] of BCR was 8.3% [2.2, 19.5] for MRI-occult cases, 17.4% [11.1, 24.8] for MRI-equivocal cases, and 43.3% [38.7, 47.8] for MRI-detectable cases (P < .001). The cumulative incidences of metastases were 0.61% [0.06, 3.1], 3.5% [1.5, 6.9], and 19.6% [15.4, 24.2] for MRI-occult, MRI-equivocal, and MRI-detectable cases, respectively (P < .001). There were no deaths from prostate cancer observed in patients with MRI-occult csPC, compared to an estimated 1.9% [0.54, 4.9], and 7.1 % [4.5, 10.6] for patients with MRI-equivocal and MRI-detectable cancer, respectively (P < .001). CONCLUSION: Oncologic outcomes after prostatectomy for csPC differ between MRI-occult and MRI-detectable lesions. Judging the clinical significance of a negative prostate MRI based on histopathologic surrogates alone might be misleading. MICROABSTRACT: Among 1449 patients with pre-prostatectomy MRI and clinically significant prostate cancer on prostatectomy histopathology, MRI-occult cancers (n = 188, 13%) were less likely to recur biochemically (8% vs. 43%, P < .001), metastasize (0.6% vs. 20%, P < .001), or lead to prostate cancer mortality (0% vs. 7%, P < .001) than MRI-detectable cancers (n = 826, 57%). MRI-occult cancers constitute a prognostically distinct subgroup among higher-grade prostate cancers.

Phase II Trial of Cabozantinib Plus Nivolumab in Patients With Non-Clear-Cell Renal Cell Carcinoma and Genomic Correlates.

PURPOSE: To assess the efficacy and safety of cabozantinib plus nivolumab in a phase II trial in patients with non-clear-cell renal cell carcinoma (RCC). PATIENTS AND METHODS: Patients had advanced non-clear-cell renal carcinoma who underwent 0-1 prior systemic therapies excluding prior immune checkpoint inhibitors. Patients received cabozantinib 40 mg once daily plus nivolumab 240 mg once every 2 weeks or 480 mg once every 4 weeks. Cohort 1 enrolled patients with papillary, unclassified, or translocation-associated RCC; cohort 2 enrolled patients with chromophobe RCC. The primary end point was objective response rate (ORR) by RECIST 1.1; secondary end points included progression-free survival, overall survival, and safety. Next-generation sequencing results were correlated with response. RESULTS: A total of 47 patients were treated with a median follow-up of 13.1 months. Objective response rate for cohort 1 (n = 40) was 47.5% (95% CI, 31.5 to 63.9), with median progression-free survival of 12.5 months (95% CI, 6.3 to 16.4) and median overall survival of 28 months (95% CI, 16.3 to not evaluable). In cohort 2 (n = 7), no responses were observed; one patient had stable disease > 1 year. Grade 3/4 treatment-related adverse events were observed in 32% treated patients. Cabozantinib and nivolumab were discontinued because of toxicity in 13% and 17% of patients, respectively. Common mutations included NF2 and FH in cohort 1 and TP53 and PTEN in cohort 2. Objective responses were seen in 10/12 patients with either NF2 or FH mutations. CONCLUSION: Cabozantinib plus nivolumab showed promising efficacy in most non-clear-cell RCC variants tested in this trial, particularly those with prominent papillary features, whereas treatment effects were limited in chromophobe RCC. Genomic findings in non-clear-cell RCC variants warrant further study as predictors of response.

A Phase Ib/II Randomized Study of RO4929097, a Gamma-Secretase or Notch Inhibitor with or without Vismodegib, a Hedgehog Inhibitor, in Advanced Sarcoma.

PURPOSE: Because the Hedgehog and Notch pathways are often overexpressed in mesenchymal malignancies, we evaluated the efficacy of concurrent inhibition of Notch and Hedgehog signaling using the gamma-secretase inhibitor (GSI) RO4929097 and the smoothened antagonist vismodegib in unresectable or metastatic sarcoma. PATIENTS AND METHODS: In this investigator-initiated trial, phase Ib used standard 3+3 dose escalation in which patients first received vismodegib once daily for 21 days, followed by the combination of RO4929097 concurrently with vismodegib in 21-day cycles. In phase II, patients were randomized to RO4929097 alone or in combination with vismodegib. RESULTS: Nine patients were treated in phase Ib with no dose-limiting toxicities. RO4929097 at 15 mg daily in combination with 150 mg daily of vismodegib was declared the recommended phase II dose. Most adverse events were grade ≤ 2. In phase II (closed early due to discontinuation of RO4929097 evaluation), 34 patients were randomized to RO4929097 alone and 33 to RO4929097 plus vismodegib. RO4929097 did not interfere with the steady-state concentration of vismodegib, while vismodegib reduced the plasma concentration of RO492909. No patients had an objective response. Neither progression-free nor overall survival differed significantly between treatment arms. Paired tumor biopsies from a subset of patients demonstrated inhibition of cleaved Notch. CONCLUSIONS: The combination of RO4929097 plus vismodegib was generally well tolerated. Although accrual to this study was not completed, vismodegib did not meaningfully enhance the clinical efficacy of RO4929097 in an unplanned analysis. GSIs and GSIs plus vismodegib can inhibit intratumoral Notch and downstream phosphorylated Akt signaling.

A phase I pharmacokinetic study of pulse-dose vorinostat with flavopiridol in solid tumors.

PURPOSE: Vorinostat (V) at levels >2.5 µM enhances chemotherapy in vitro. Yet the approved oral dose of 400 mg inconsistently achieves this level in patients. We developed an intermittent oral pulse-dose schedule of V to increase serum levels. We combined V with the cyclin dependent kinase inhibitor flavopiridol (F) which increases V-induced apoptosis. EXPERIMENTAL DESIGN: One week before combination treatment, V alone was given daily for 3d (cycle -1). Then V was given on d1-3 and d8-10, and F on d2 and d9, every 21-d. Due to neutropenia, this was modified to V on d1-3 and d15-17, and F on d2 and d16, every 28-d. Bolus and split-dose F schedules were studied. RESULTS: 34 patients were treated. On the 21-d schedule, the maximum tolerated dose (MTD) was V 600 mg/d and F 60 mg/m(2) bolus. On the 28-d schedule, the MTD was V 800 mg/d and F 30 mg/m(2) over 30 min and 30 mg/m(2) over 4 h. V C(max) at the 800 mg dose was 4.8 µM (± 2.8). V C(max) ≥ 2.5 µM was achieved in 86% of patients at the MTD. F increased the C(max) of V by 27% (95% CI 11%-43%). F C(max) of ≥ 2 µM was achieved in 90% of patients. 8 patients had stable disease for on average 5.5 m (range 1.6-13.2 m). CONCLUSIONS: Intermittent high dose oral V in combination with F is feasible and achieves target serum levels >2.5 µM. V concentrations higher than previously reported with oral dosing were achieved.