Gene Greenzweig

Bio: Gene Greenzweig is an academic researcher. The author has contributed to research in topics: Miami. The author has an hindex of 1, co-authored 2 publications receiving 47 citations.

Rituximab Targets Podocytes in Recurrent Focal Segmental Glomerulosclerosis

Abstract: Focal segmental glomerulosclerosis (FSGS) is a glomerular disease characterized by proteinuria, progression to endstage renal disease, and recurrence of proteinuria after kidney transplantation in about one-third of patients. It has been suggested that rituximab might treat recurrent FSGS through an unknown mechanism. Rituximab not only recognizes CD20 on B lymphocytes, but might also bind sphingomyelin phosphodiesterase acid-like 3b (SMPDL-3b) protein and regulate acid sphingomyelinase (ASMase) activity. We hypothesized that rituximab prevents recurrent FSGS and preserves podocyte SMPDL-3b expression. We studied 41 patients at high risk for recurrent FSGS, 27 of whom were treated with rituximab at time of kidney transplant. SMPDL-3b protein, ASMase activity, and cytoskeleton remodeling were studied in cultured normal human podocytes that had been exposed to patient sera with or without rituximab. Rituximab treatment was associated with lower incidence of posttransplant proteinuria and stabilization of glomerular filtration rate. The number of SMPDL-3b + podocytes in postreperfusion biopsies was reduced in patients who developed recurrent FSGS. Rituximab partially prevented SMPDL-3b and ASMase down-regulation that was observed in podocytes treated with the sera of patients with recurrent FSGS. Overexpression of SMPDL-3b or treatment with rituximab was able to prevent disruption of the actin cytoskeleton and podocyte apoptosis induced by patient sera. This effect was dimin ished in cultured podocytes whereSMPDL-3b was silenced. Our study suggests that treatment of high-risk patients with rituximab at time of kidney transplant might prevent recurrent FSGS by modulating podocyte function in an SMPDL-3b–dependent manner.

Active surveillance for prostate cancer: current evidence and contemporary state of practice

Abstract: Prostate cancer remains one of the most commonly diagnosed malignancies worldwide. Early diagnosis and curative treatment seem to improve survival in men with unfavourable-risk cancers, but significant concerns exist regarding the overdiagnosis and overtreatment of men with lower-risk cancers. To this end, active surveillance (AS) has emerged as a primary management strategy in men with favourable-risk disease, and contemporary data suggest that use of AS has increased worldwide. Although published surveillance cohorts differ by protocol, reported rates of metastatic disease and prostate-cancer-specific mortality are exceedingly low in the intermediate term (5-10 years). Such outcomes seem to be closely associated with programme-specific criteria for selection, monitoring, and intervention, suggesting that AS--like other management strategies--could be individualized based on the level of risk acceptable to patients in light of their personal preferences. Additional data are needed to better establish the risks associated with AS and to identify patient-specific characteristics that could modify prognosis.

Impact of breast cancer subtypes and patterns of metastasis on outcome

Abstract: Clinical outcome of patients with stage IV breast cancer is dependent on tumor biology, extent, and localization of metastases. Routine imaging diagnostics for distant metastasis is not recommended by the national guidelines for breast cancer follow-up. In this study, we evaluated different patterns of metastases of cancer subtypes in order to generate hypotheses on individualization of follow-up after breast cancer in the adjuvant setting. Patients of the Regional Breast Cancer Center Dresden diagnosed within the years 2006-2011 were classified into the five intrinsic subtypes luminal A (ER+, Her2-, G1/2), luminal B/Her2 negative (ER+, Her2-, G3), triple positive (ER+, PR+, Her2+), Her2-enriched (ER-, Her2+), and triple negative (ER-, PR-, Her2-) and with a median follow-up of 45 months. Tumor stage at time of first diagnosis of breast cancer as well as time and site of metastasis at first diagnosis of distant metastatic disease was analyzed. Tumor specimen of 2284 female patients with primary breast cancer was classified into five subtypes. Distant recurrence-free survival at 3 years was most unfavorable in Her2-enriched (66.8 %), triple negative (75.9 %), and triple-positive breast cancer (81.7 %). The same subtypes most frequently presented with visceral metastases only at first presentation: Her2-enriched 46.9 %, triple negative 45.5 %, and triple-positive breast cancer 37.5 %. Longest median survival of 2.3 years was seen in luminal A and in Her2-enriched metastatic disease, respectively. Median survival was significantly better in the luminal A, Her2-enriched, and triple-positive subtype compared to triple-negative breast cancer (p < 0.005). Differences in time to metastatic disease, first localization of metastases, and overall survival after diagnosis of metastatic disease were shown. Considering new targeted therapies and the option of surgery of oligometastases, screening for visceral metastases might be reasonable after diagnosis of Her2-positive subtypes.