Notch4 is required for tumor onset and perfusion

Abstract Background Notch4 is a member of the Notch family of receptors that is primarily expressed in the vascular endothelial cells. Genetic deletion of Notch4 does not result in an overt phenotype in mice, thus the function of Notch4 remains poorly understood. Methods We examined the requirement for Notch4 in the development of breast cancer vasculature. Orthotopic transplantation of mouse mammary tumor cells wild type for Notch4 into Notch4 deficient hosts enabled us to delineate the contribution of host Notch4 independent of its function in the tumor cell compartment. Results Here, we show that Notch4 expression is required for tumor onset and early tumor perfusion in a mouse model of breast cancer. We found that Notch4 expression is upregulated in mouse and human mammary tumor vasculature. Moreover, host Notch4 deficiency delayed the onset of MMTV-PyMT tumors, wild type for Notch4, after transplantation. Vessel perfusion was decreased in tumors established in Notch4-deficient hosts. Unlike in inhibition of Notch1 or Dll4, vessel density and branching in tumors developed in Notch4-deficient mice were unchanged. However, final tumor size was similar between tumors grown in wild type and Notch4 null hosts. Conclusion Our results suggest a novel role for Notch4 in the establishment of tumor colonies and vessel perfusion of transplanted mammary tumors

Long‐term overall survival of radical prostatectomy patients is often superior to the general population: A comparison using life‐table data

Background: To examine overall survival rates within a large cohort of German prostate cancer (PCa) patients and to compare these with life-expectancy (LE) predictions derived from German life tables. We hypothesized that the advantage of good general health in radical prostatectomy (RP) patients combined with favorable cancer outcomes might lead to even higher overall survival rates over 10 years compared to the LE of a general population. Methods: A total of 6483 patients were treated with RP between 1992 and 2007 at the Martini-Klinik Prostate Cancer Center. Preoperative risk classification was performed according to D'Amico. Postoperative risk classification was performed according to the Cancer of the Prostate Risk Assessment score (CAPRA-S). A simulated cohort was created that resembled the exact age distribution of the RP population using Monte Carlo simulation which was based on data derived from official male German life tables (1992–2017). Markov chain was used to represent natural age progression of the simulated cohort. Kaplan–Meier plots were created to display the differences between 10-year observed overall survival (OS) and the simulated, predicted LE. Results: For D'Amico low risk and intermediate risk, 10-year OS was 12.0% and 9.2% above predicted LE in the simulated cohort, respectively. For D'Amico high risk, OS was virtually the same as predicted LE (0.8% difference in favor of RP treated patients). For CAPRA-S low and intermediate risk, OS was 11.8% and 9.7% above predicted LE. For CAPRA-S high risk, OS was virtually the same as predicted LE (0.3% difference in favor of the simulated cohort). Conclusions: Low- and intermediate risk PCa patients treated with RP can expect a very favorable overall survival, that even exceeds LE predictions. High risk patients' overall survival perfectly aligns with LE predictions