Allele Loss and Reduced Expression of CYCLOPS Genes is a Characteristic Feature of Chromophobe Renal Cell Carcinoma

Copy-number alterations Yielding Cancer Liabilities Owing to Partial losS (CYCLOPS) genes have been recently identified as the most enriched class of copy-number associated gene dependencies in human cancer. These genes are cell essential and render tumor cells highly sensitive to the expression of the remaining copy. Chromophobe renal cell carcinoma (chRCC) is characterized by frequent chromosomal deletions, but the relevance of CYCLOPS genes in this tumor subtype is unclear. We found 39 (31%) of 124 recently published candidate CYCLOPS genes (B. Paolella et al., eLife 2017;6:e23268) located on 7 autosomes that are frequently lost in chRCC. GISTIC and RNA-seq data obtained from the TCGA-KICH database showed that 62% of these CYCLOPS genes had significantly lower expression levels in samples with deletion of the respective gene. As copy number (CN) loss of the CYCLOPS gene SF3B1 (Splicing factor 3B subunit 1) has been recently reported in 71% chRCC, we explored the relevance of SF3B1 CN alteration and SF3B1 expression in a set of chRCC and additional oncocytic renal neoplasms. The frequency of SF3B1 CN loss (65%) was similar to that obtained from the TCGA-KICH database and correlated significantly with both lower SF3B1 mRNA (P < .05) and protein expression (P < .001). Other tumor subtypes with oncocytic cytoplasm had normal SF3B1 CN and displayed strong SF3B1 protein expression. These results suggest that CN loss of CYCLOPS genes is a characteristic feature in chRCC. Since many CYCLOPS genes code for components of proteasomes and transcriptional regulation, their alteration could make chRCC vulnerable to targeted drugs.

A new payment system for outpatient services? The implications for radiology

Congress is now contemplating the most significant change in outpatient payment methodology in Medicare's 31-year history. It may approve a proposal by the Health Care Financing Administration (HCFA) to establish a Medicare prospective payment system for hospital outpatient departments. In March 1955, five years after a Congressional directive to develop a new outpatient payment system, HCFA delivered its proposal recommending use of the ambulatory patient groups (APG) classification system for determining payment of hospital outpatient services. The APG system, which uses outpatient procedures as its primary variable, divides all such procedures into one of three categories: 1) significant procedures or therapies (including therapeutic and other significant radiological procedures); 2) ancillary test and procedures (including 11 radiology ancillary service APGs); or 3) medical visits. Outpatients can be assigned to one or more of the 290 APGs, each comprising a number of clinically and resource intensity-similar procedures, medical visits or ancillary tests. Any new payment methodology for outpatient procedures would broadly impact the radiology community. How radiology providers will fare under the system being proposed will depend on several issues that have not yet been resolved, such as how the basic unit of payment is defined (e.g., a service, a visit, or an episode of care) and whether payment rates will be adequate to compensate for the costs of providing services. One key issue will be whether contrast media and radiopharmaceuticals will continue to be paid as pass-through costs, giving providers the flexibility to choose the specific agent that is most appropriate for their patients.