Targeting Transcriptional Regulation with a CDK9 Inhibitor Suppresses Growth of Endocrine- and Palbociclib-Resistant ER+ Breast Cancers.

The combination of endocrine therapy and CDK4/6 inhibitors such as palbociclib is an effective and well-tolerated treatment for estrogen receptor-positive (ER+) breast cancer, yet many patients relapse with therapy-resistant disease. Determining the mechanisms underlying endocrine therapy resistance is limited by the lack of ability to fully recapitulate inter- and intratumor heterogeneity in vitro and of availability of tumor samples from women with disease progression or relapse. In this study, multiple cell line models of resistant disease were used for both two-dimensional (2D)- and three-dimensional (3D)-based inhibitor screening. The screens confirmed the previously reported role of pro-proliferative pathways, such as PI3K-AKT-mTOR, in endocrine therapy resistance and additionally identified the transcription-associated cyclin-dependent kinase CDK9 as a common hit in ER+ cell lines and patient-derived organoids modeling endocrine therapy-resistant disease in both the palbociclib-sensitive and palbociclib-resistant settings. The CDK9 inhibitor, AZD4573, currently in clinical trials for hematologic malignancies, acted synergistically with palbociclib in these ER+in vitro 2D and 3D models. In addition, in two independent endocrine- and palbociclib-resistance patient-derived xenografts, treatment with AZD4573 in combination with palbociclib and fulvestrant resulted in tumor regression. Tumor transcriptional profiling identified a set of transcriptional and cell-cycle regulators differentially downregulated only in combination-treated tumors. Together, these findings identify a clinically tractable combination strategy for overcoming resistance to endocrine therapy and CDK4/6 inhibitors in breast cancer and provide insight into the potential mechanism of drug efficacy in targeting treatment-resistant disease. SIGNIFICANCE: Targeting transcription-associated CDK9 synergizes with CDK4/6 inhibitor to drive tumor regression in multiple models of endocrine- and palbociclib-resistant ER+ breast cancer, which could address the challenge of overcoming resistance in patients.

Intraoperative Frozen Section of the Prostate Reduces the Risk of Positive Margin Whilst Ensuring Nerve Sparing in Patients with Intermediate and High-Risk Prostate Cancer Undergoing Robotic Radical Prostatectomy: First Reported UK Series.

INTRODUCTION: Nerve sparing during robotic radical prostatectomy (RRP) considerably improves post-operative potency and urinary continence as long as it does not compromise oncological outcome. Excision of the neurovascular bundle (NVB) is often performed in patients with intermediate and high risk prostate cancer to reduce the risk of positive surgical margin raising the risk of urinary incontinence and impotence. We present the first UK series outcomes of such patients who underwent an intra-operative frozen section (IOFS) analysis of the prostate during RRP allowing nerve sparing. PATIENTS AND METHODS: We prospectively analysed the data of 40 patients who underwent an IOFS during RRP at our centre from November 2012 until November 2014. Our IOFS technique involved whole lateral circumferential analysis of the prostate during RRP with the corresponding neurovascular tissue. An intrafascial nerve spare was performed and the specimen was removed intra-operatively via an extension of the 12 mm Autosuture™ camera port without undocking robotic arms. It was then painted by the surgeon and sprayed with "Ink Aid" prior to frozen section analysis. The corresponding NVB was excised if the histopathologist found a positive surgical margin on frozen section. RESULTS: Median time to extract the specimen, wound closure and re-establishment of pneumoperitoneum increased the operative time by 8 min. Median blood loss for IOFS was 130 ± 97 ml vs. 90 ± 72 ml (p = NS). IOFS was not associated with major complications or with blood transfusion. PSM decreased significantly from non-IOFS RRP series of 28.7 to 7.8% (p < 0.05). Intra-operative PSM on the prostate specimen was seen in 8/40 margin analysis (20%) leading to an excision of the contra-lateral nerve bundle. On analysis of the nerve bundle on a paraffin embedded block, 6 nerve bundle matched tumor on the specimen whereas 2 NVB were retrospectively removed unnecessarily in our series. All 40 patients have undetectable PSA at a mean follow up of 21.2 months (SD 7.79). Functional data at 18 months confirms a reduction in the urinary incontinence from 37% in the IOFS group vs 57% in the non-IOFS group (p = NS). IOFS technique has resulted in a significant increase in intravesical nerve sparing in both T2/T3 patients with intermediate and high risk prostate cancer when appropriately counselled and selected (T2 from 100% in the IOFS group versus 67% and T3 from 100% in the IOFS group to 42%) (p < 0.05). CONCLUSION: Introduction of the IOFS analysis during intrafascial nerve spare RRP has reduced PSM and the rate of urinary incontinence.

Scoring systems for the post-thrombotic syndrome.

OBJECTIVE: To assess each of the scoring systems used to diagnose and classify post-thrombotic syndrome, a common chronic complication of deep vein thrombosis. The design of the study was a systematic review of the literature pertaining to post-thrombotic syndrome. METHODS: A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines by a search of PubMed (1948 to September 2011) using the search terms "post-thrombotic syndrome," "postthrombotic syndrome," "post-phlebitic syndrome," and "postphlebitic syndrome." A manual reference list search was also carried out to identify further studies that would be appropriate for inclusion. The various scoring systems in use were identified and assessed against a list of criteria to determine their validity for use. For outcome measures, each scoring system was assessed for specific criteria, including interobserver reliability, association with ambulatory venous pressures, ability to assess severity of post-thrombotic syndrome, ability to assess change in condition over time, and association with patient-reported symptom severity. RESULTS: The Villalta, Ginsberg, Brandjes, Widmer, CEAP, and Venous Clinical Severity Score systems all were assessed for the stated outcome measures. From their use in the literature, only the Villalta score was able to fulfill all the criteria described. The main criticism of the Villalta score in the literature appears to be its use of subjective measures. To that end, we propose that use of a venous disease-specific quality-of-life questionnaire in combination with the Villalta score may help standardize the subjective criteria. CONCLUSIONS: The Villalta score, combined with a venous disease-specific quality-of-life questionnaire, should be considered the "gold standard" for the diagnosis and classification of post-thrombotic syndrome.