Active surveillance of metastatic renal cell carcinoma: Results from a prospective observational study (MaRCC).

BACKGROUND: Systemic therapy (ST) can be deferred in patients who have metastatic renal cell carcinoma (mRCC) and slow-growing metastases. Currently, this subset of patients managed with active surveillance (AS) is not well described in the literature. METHODS: This was a prospective observational study of patients with mRCC across 46 US community and academic centers. The objective was to describe baseline characteristics and demographics of patients with mRCC initially managed by AS, reasons for AS, and patient outcomes. Descriptive statistics were used to characterize demographics, baseline characteristics, and patient-related outcomes. Wilcoxon 2-sample rank-sum tests and χ2 tests were used to assess differences between ST and AS cohorts in continuous and categorical variables, respectively. Kaplan-Meier survival curves were used to assess survival. RESULTS: Of 504 patients, mRCC was initially managed by AS (n = 143) or ST (n = 305); 56 patients were excluded from the analysis. Disease was present in 69% of patients who received AS, whereas the remaining 31% had no evidence of disease. At data cutoff, 72 of 143 patients (50%) in the AS cohort had not received ST. The median overall survival was not reached (95% CI, 122 months to not estimable) in patients who received AS versus 30 months (95% CI, 25-44 months) in those who received ST. Quality of life at baseline was significantly better in patients who were managed with AS versus ST. CONCLUSIONS: AS occurs frequently (32%) in real-world clinical practice and appears to be a safe and appropriate alternative to immediate ST in selected patients.

Ascorbic acid-induced TET activation mitigates adverse hydroxymethylcytosine loss in renal cell carcinoma.

Although clear cell renal cell carcinoma (ccRCC) has been shown to result in widespread aberrant cytosine methylation and loss of 5-hydroxymethylcytosine (5hmC), the prognostic impact and therapeutic targeting of this epigenetic aberrancy has not been fully explored. Analysis of 576 primary ccRCC samples demonstrated that loss of 5hmC was strongly associated with aggressive clinicopathologic features and was an independent adverse prognostic factor. Loss of 5hmC also predicted reduced progression-free survival after resection of nonmetastatic disease. The loss of 5hmC in ccRCC was not due to mutational or transcriptional inactivation of ten eleven translocation (TET) enzymes, but to their functional inactivation by l-2-hydroxyglutarate (L2HG), which was overexpressed due to the deletion and underexpression of L2HG dehydrogenase (L2HGDH). Ascorbic acid (AA) reduced methylation and restored genome-wide 5hmC levels via TET activation. Fluorescence quenching of the recombinant TET-2 protein was unaffected by L2HG in the presence of AA. Pharmacologic AA treatment led to reduced growth of ccRCC in vitro and reduced tumor growth in vivo, with increased intratumoral 5hmC. These data demonstrate that reduced 5hmC is associated with reduced survival in ccRCC and provide a preclinical rationale for exploring the therapeutic potential of high-dose AA in ccRCC.

Toxicities following treatment with bisphosphonates and receptor activator of nuclear factor-κB ligand inhibitors in patients with advanced prostate cancer.

CONTEXT: Advanced prostate cancer (PCa) is associated with skeletal complications, both as a result of bone metastases and because of fractures associated with fragility due to androgen-deprivation therapy (ADT). Osteoclast inhibitors are commonly used to reduce skeletal complications but are associated with a number of potential adverse events. OBJECTIVE: To review clinical trials of osteoclast inhibitors in advanced PCa, to discuss the adverse event profile of these agents, and to discuss strategies to address specific adverse events. EVIDENCE ACQUISITION: PubMed was searched for reports of clinical trials of osteoclast inhibitors in advanced PCa. As zoledronic acid and denosumab are used most commonly in this disease, these trials were the focus. The literature was reviewed to identify key publications addressing the prevention and management of adverse events associated with these drugs. EVIDENCE SYNTHESIS: The major findings of the trials and the adverse events are discussed. Prevention and management of common adverse events are addressed. CONCLUSIONS: Zoledronic acid prevents loss of bone mineral density associated with ADT and delays skeletal-related events in metastatic castration-resistant PCa (mCRPC). Denosumab reduces the incidence of fragility fractures associated with ADT, delays the onset of bone metastases in nonmetastatic castration-resistant disease, and is superior to zoledronic acid in the prevention of skeletal complications in mCRPC. Adverse events associated with both agents include osteonecrosis of the jaw and hypocalcemia. Hypocalcemia is more common with denosumab. Zoledronic acid requires dose modifications for renal insufficiency, is contraindicated in severe renal insufficiency, and has been associated with deterioration of renal function. Appropriate patient selection with close attention to dental health, supplementation with calcium and vitamin D, and monitoring of laboratory values are effective strategies to minimize the impact of adverse events associated with osteoclast inhibitors in advanced PCa.