Bone marrow biopsy: RNA isolation with expression profiling in men with metastatic castration-resistant prostate cancer--factors affecting diagnostic success.

PURPOSE: To determine the rate at which computed tomographically guided pelvic percutaneous bone biopsy in men with metastatic castration-resistant prostate cancer (mCRPC) yields adequate tissue for genomic profiling and to identify issues likely to affect diagnostic yields. MATERIALS AND METHODS: This study was institutional review board approved, and written informed consent was obtained. In a phase II trial assessing response to everolimus, 31 men with mCRPC underwent 54 biopsy procedures (eight men before and 23 men both before and during treatment). Variables assessed were lesion location (iliac wing adjacent to sacroiliac joint, iliac wing anterior and/or superior to sacroiliac joint, sacrum, and remainder of pelvis), mean lesion attenuation, subjective lesion attenuation (purely sclerotic vs mixed), central versus peripheral lesion sampling, lesion size, core number, and use of zoledronic acid for more than 1 year. RESULTS: Of 54 biopsy procedures, 21 (39%) yielded adequate tissue for RNA isolation and genomic profiling. Three of four sacral biopsies were adequate. Biopsies of the ilium adjacent to the sacroiliac joints were more likely adequate than those from elsewhere in the ilium (48% vs 28%, respectively). All five biopsies performed in other pelvic locations yielded inadequate tissue for RNA isolation. Mean attenuation of lesions with inadequate tissue was 172 HU greater than those with adequate tissue (621.1 HU ± 166 vs 449 HU ± 221, respectively; P = .002). Use of zoledronic acid, peripheral sampling, core number, and lesion size affected yields, but the differences were not statistically significant. Histologic examination with hematoxylin-eosin staining showed that results of 36 (67%) biopsies were positive for cancer; only mean attenuation differences were significant (707 HU ± 144 vs 473 HU ± 191, negative vs positive, respectively; P < .001). CONCLUSION: In men with mCRPC, percutaneous sampling of osseous metastases for genomic profiling is possible, but use of zoledronic acid for more than 1 year may reduce the yield of adequate tissue for RNA isolation. Sampling large low-attenuating lesions at their periphery maximizes yield.

A Single-Arm Phase 1b Study of Everolimus and Sunitinib in Patients With Advanced Renal Cell Carcinoma.

BACKGROUND: Everolimus, an oral inhibitor of mammalian target of rapamycin (mTOR), and sunitinib, an oral inhibitor of vascular endothelial growth factor (VEGF)/platelet-derived growth factor receptor tyrosine kinase signaling, have both been shown to provide clinical benefit in patients with advanced renal cell carcinoma (RCC). We sought to determine the safety and efficacy of combination therapy with these agents in patients with advanced RCC. METHODS: We conducted a phase 1b dose escalation trial of sunitinib and everolimus in patients with advanced metastatic RCC. Prior nephrectomy was required, and prior radiation or chemotherapy other than VEGF/mTOR-based therapies was permitted. The primary end point was to determine the maximum tolerated dose/recommended phase 2 dose. RESULTS: A total of 4 out of a planned 30 subjects were enrolled onto this study (M:F = 2:2; mean age 52 years, 50% with Karnofsky performance status < 80). The first 3 patients were enrolled onto a 4 + 2 dosing schedule of daily sunitinib 50 mg and weekly everolimus 30 mg. Mean time receiving drug was 99 days. One partial response was seen. Toxicities included mucositis, thrombocytopenia, anemia, fatigue, dehydration, and hypoglycemia. Because of multiple grade 3 to 4 toxicities, the protocol was amended to 2 + 1 dosing of sunitinib 37.5 mg and daily everolimus 5 mg. The first patient on this schedule died from multiorgan failure with septic shock after 1 cycle of treatment. Subsequently, the study was closed. Pharmacokinetic results inconclusively suggest that toxicities could be attributed to the drug exposure. CONCLUSION: Combined use of everolimus and sunitinib in the treatment of metastatic RCC was not well tolerated in this small cohort.

Activity of single-agent bevacizumab in patients with metastatic renal cell carcinoma previously treated with vascular endothelial growth factor tyrosine kinase inhibitors.

PURPOSE: The activity of systemic agents after progression when using vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibition (TKI) and mammalian target of rapamycin (mTOR) inhibition in patients with metastatic renal cell carcinoma (mRCC) is poorly characterized. The anti-vascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab has a broad US Food and Drug Administration label and National Comprehensive Cancer Network guideline level 2b recommendation in this setting; we thus explored our institutional experience in this population. METHODS: We conducted a retrospective analysis of patients with mRCC who were treated with bevacizumab in the second- and/or third-line settings; the primary endpoint was progression-free survival (PFS). Overall response rates (ORR), overall survival (OS), and toxicity were analyzed. RESULTS: Twenty-one patients were treated with bevacizumab: the median age was 63 years old; 80% were white and 14% were black; 80% had clear cell histology. All the patients had prior VEGFR TKI therapy; 43% had prior mTOR inhibitor; the median number of prior therapies was 3. The median PFS was 4.4 months (95% CI, 2.8-9.6 months), and the median OS was 19.4 months (95% CI, 9.9-NR months). ORR was 9.5%; 52% of subjects had stable disease as best response, and 52% had disease progression. For subjects treated with prior VEGF and mTOR inhibitors, median PFS and OS were 4.4 and 13.2 months, respectively. Grade 3 to 4 toxicities included fatigue (29%), dehydration (24%), failure to thrive (10%), constipation (10%), and muscle weakness (10%). CONCLUSIONS: Single-agent bevacizumab has acceptable toxicity and moderate disease-stabilizing activity in selected patients with mRCC who have failed prior VEGFR TKI and mTOR inhibitors. These data support clinical benefit to continued ongoing VEGF inhibition. Further prospective studies of bevacizumab alone or with alternative targeted agents in previously treated populations with mRCC are warranted.

Circulating tumor cells from patients with advanced prostate and breast cancer display both epithelial and mesenchymal markers.

During cancer progression, malignant cells undergo epithelial-mesenchymal transitions (EMT) and mesenchymal-epithelial transitions (MET) as part of a broad invasion and metastasis program. We previously observed MET events among lung metastases in a preclinical model of prostate adenocarcinoma that suggested a relationship between epithelial plasticity and metastatic spread. We thus sought to translate these findings into clinical evidence by examining the existence of EMT in circulating tumor cells (CTC) from patients with progressive metastatic solid tumors, with a focus on men with castration-resistant prostate cancer (CRPC) and women with metastatic breast cancer. We showed that the majority (> 80%) of these CTCs in patients with metastatic CRPC coexpress epithelial proteins such as epithelial cell adhesion molecule (EpCAM), cytokeratins (CK), and E-cadherin, with mesenchymal proteins including vimentin, N-cadherin and O-cadherin, and the stem cell marker CD133. Equally, we found that more than 75% of CTCs from women with metastatic breast cancer coexpress CK, vimentin, and N-cadherin. The existence and high frequency of these CTCs coexpressing epithelial, mesenchymal, and stem cell markers in patients with progressive metastases has important implications for the application and interpretation of approved methods to detect CTCs.