The Benefit of Combining Docetaxel with Androgen Deprivation Therapy in Localized and Metastatic Hormone-sensitive Prostate Cancer is Predicted by ERG Expression: An Analysis of Two GETUG Phase 3 Trials.

BACKGROUND AND OBJECTIVE: Docetaxel has become a standard component of care for advanced prostate cancer (PC); however, its benefits are not universal among patients. A subset of PC cases exhibit TMPRSS2-ERG gene fusion, resulting in ERG overexpression in tumors. Our aim was to assess biomarkers for docetaxel efficacy in men with hormone-sensitive PC (HSPC). METHODS: Pretreatment prostate biopsies were obtained from participants in two randomized phase 3 clinical trials investigating docetaxel in high-risk localized PC (GETUG 12) and metastatic HSPC (GETUG 15). Immunohistochemistry staining for Ki67, PTEN, RB, and phosphorylated RB was conducted for GETUG 12 samples, and ERG staining for GETUG 12 and GETUG 15 samples. We examined biomarker association with outcomes using univariate and multivariable analyses adjusted for other validated prognostic factors. KEY FINDINGS AND LIMITATIONS: Among GETUG 12 patients, Ki67 was associated with a worse relapse-free survival (RFS; hazard ratio [HR] 1.72; p = 0.0092). A pooled analysis for the two trials (pinteraction = 0.056) revealed that docetaxel-based chemotherapy improved failure-free survival for patients with ERG-positive cancer (HR 0.58; p = 0.03), but not patients with ERG-negative cancer (HR 1.08; p = 0.72). In the ERG-positive subgroup in GETUG 12 (high-risk localized PC), median RFS was 7.79 yr with androgen deprivation therapy (ADT) alone, and was not reached with ADT + docetaxel. In the ERG-negative subgroup, median progression-free survival (mPFS) was 7.79 yr with ADT alone versus 7.08 yr with ADT + docetaxel. In the ERG-positive subgroup in GETUG 15 (metastatic HSPC), mPFS was 10.7 mo with ADT alone versus 18.8 mo with ADT + docetaxel. In the ERG-negative subgroup, mPFS was 10.6 mo with ADT alone versus 13.2 mo with ADT + docetaxel. CONCLUSIONS AND CLINICAL IMPLICATIONS: Ki67 may serve as a prognostic factor in HSPC, while ERG expression appears to predict a response to docetaxel in both high-risk localized and metastatic HSPC. PATIENT SUMMARY: We assessed factors that could predict outcomes after docetaxel chemotherapy in patients with advanced prostate cancer. We found that expression of a protein called ERG can predict a good response to docetaxel in these patients.

[Supervision after breast cancer treatment]. / Surveillance après un traitemnent du cancer du sein.

Breast cancer screening and therapeutic advances have significantly decreased breast cancer mortality. Nearly 80% of patients with a localized disease will experience a prolonged survival and the organization of their monitoring is critical to early detection of local or metastatic relapse. Annual mammography is recommanded for the follow up and no further imaging examination is routinely necessary. Early diagnosis of metastatic relapse has not demonstrated evidence of survival benefit. However, treatments are not without toxicities and data about long-term complications are missing. The socio-economic consequences for these patients need to be evaluated and cardiovascular toxicities of chemotherapy and hormonal therapy are probably underestimated.

Targeting CDC25C, PLK1 and CHEK1 to overcome Docetaxel resistance induced by loss of LZTS1 in prostate cancer.

Docetaxel is used as a standard treatment in patients with metastatic castration-resistant prostate cancer. However, a large subset of patients develops resistance. Understanding resistance mechanisms, which are largely unknown, will allow identification of predictive biomarkers and therapeutic targets. We established resistant IGR-CaP1 prostate cancer cell lines for different doses of Docetaxel. We investigated gene expression profiles by microarray analyses in these cell lines and generated a signature of 99 highly differentially expressed genes potentially implicated in chemoresistance. We focused on the role of the cell cycle regulator LZTS1, which was under-expressed in the Docetaxel-resistant cell lines, its inhibition resulting from the promoter methylation. Knockdown of LZTS1 in parental cells with siRNA showed that LZTS1 plays a role in the acquisition of the resistant phenotype. Furthermore, we observed that targeting CDC25C, a partner of LZTS1, with the NSC663284 inhibitor specifically killed the Docetaxel-resistant cells. To further investigate the role of CDC25C, we used inhibitors of the mitotic kinases that regulate CDC25C. Inhibition of CHEK1 and PLK1 induced growth arrest and cell death in the resistant cells. Our findings identify an important role of LZTS1 through its regulation of CDC25C in Docetaxel resistance in prostate cancer and suggest that CDC25C, or the mitotic kinases CHEK1 and PLK1, could be efficient therapeutic targets to overcome Docetaxel resistance.

Bone targeted therapies in metastatic castration-resistant prostate cancer.

Prostate cancer is the most common male cancer. About 90% of metastatic patients will develop bone metastases. Bone disease is responsible of pain, deterioration of quality of life and serious bone complications. Proliferation of prostate cancer cells in the bone marrow induces osteoclast activation and osteolysis. Targeting the bone microenvironment reduces morbidity. Relevant preclinical and clinical studies of bone-targeted therapies in castration-resistant prostate cancer were identified in PubMed and clinical trial databases. Different drugs are available or in development that target bone resorption (bisphosphonates, RANK ligand inhibitors), bone formation (endothelin 1 inhibitors), cancer cell migration (SRC-family kinase inhibitors, vascular endothelial growth factor-MET inhibitors), and survival (radiopharmaceuticals). In phase III trials, zoledronic acid, denosumab, and radium-223 were shown to significantly delay skeletal-related events. Radium-223 was also shown to improve overall survival. Biomarkers of bone resorption (urinary N-telopeptide) and bone making (alkaline phosphatase) have an independent prognostic impact. Targeting the bone microenvironment is an important component of castration-resistant prostate cancer management to reduce bone complications and improve overall survival. Biomarkers of bone turnover have an independent prognostic impact.

[Telomeres: a Nobel Prize at the beginning of the end]. / Télomères : un Nobel pour le début de la fin.

The 2009 Nobel Prize for Physiology and Medicine was awarded to Elizabeth H. Blackburn, Carol W. Greider and Jack K. Szostak for their work on telomeres and telomerase. This prize acknowledges their pionneering discoveries on chromosomal extremities. Telomeres are the nucleoproteic complexes that may be found at the ends of linear chromosomes. They are essential for genomic stability and are involved in aging and tumorogenesis.