Patients with BRCA-1 and BRCA-2 germ line mutations are at an increased risk of developing pancreatic adenocarcinoma (PAC). In particular, the BRCA-2 mutation has been associated with a relative risk of developing PAC of 3.51. The BRCA-2 protein is involved in repair of double-stranded DNA breaks. Recent reports have suggested that in the setting of impaired DNA repair, chemotherapeutic agents that induce DNA damage, such as platinum-based antineoplastic drugs (platins) and poly(ADP-ribose) polymerase inhibitors (PARP inhibitors), have improved efficacy. However, because of the relative rarity of BRCA-related PAC, studies evaluating such agents in this setting are scarce. Patients with a known BRCA-2 mutation and PAC were retrospectively reviewed. Ten patients with PAC and BRCA-2 mutation were identified. Four patients (40%) were of Ashkenazi Jewish descent. Seven patients (70%) received platinum agents, two (20%) received mitomycin-C, one (10%) received a PARP inhibitor, and seven (70%) received a topoisomerase-I inhibitor. Overall, chemotherapy was well tolerated with expected side effects. Patients with a BRCA-2 mutation and PAC represent a group with a unique biology underlying their cancer. Chemotherapies such as platinum derivatives, mitomycin-C, topoisomerase-I inhibitors, and PARP inhibitors targeting DNA require further investigation in this population. Genetic testing may guide therapy in the future.
Background: Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative option for patients with myelofibrosis (MF). Reduced-intensity conditioning (RIC) regimens have been used to extend this therapy to older and sicker patients. Splenectomy prior to HSCT for MF has been shown to enhance neutrophil engraftment and decrease transfusion requirements, but has a reported operative mortality of 9% or higher. Splenic irradiation (sXRT) has been historically used as a palliative treatment in MF. We present our experience with a RIC regimen incorporating extracorporeal photopheresis (ECP) in combination with either pre-HSCT splenectomy or sXRT. Methods: The Tufts BMT database, the Center for International Bone Marrow Transplantation Registry (CIBMTR) database, and chart review were used to gather data. All patients underwent conditioning consisting of ECP administered on days -6 and -5, pentostatin 4mg/m2by continuous infusion over 48 hours on days -4 and -3, and a total dose of 600 cGy total body irradiation (TBI) administered in 3 fractions on days -2 and -1 (PPT). sXRT, when employed, was given in the week prior to start of PPT (days -6 to -11) with total doses ranging from 300 to 500cGy. Cyclosporine and methotrexate were used for GVHD prophylaxis. Patients surviving a minimum of six months were considered evaluable for response assessment. Complete hematologic response was defined as resolution of clinical signs of MF as well as normalization of peripheral blood counts (Hgb>10gm/dL, ANC>1000/µL, Platelets >100K and all counts below upper limit of normal) and the absence circulating blasts. Histological response could not be assessed due to lack of follow-up bone marrow data. Clinical improvement, stable disease, progressive disease, spleen response were defined using revised IWG-MRT guidelines. Overall survival (OS) was estimated using the Kaplan Meier method from time of stem cell transplant to death. Non-relapse mortality (NRM) was estimated from time of transplant to death, treating death due to MF and relapse as competing risks. Results: Ten patients (7 females, 3 males) with MF underwent allogeneic HSCT with PPT conditioning between February 2001 and December 2012. Median age was 54 years (40-60 years). Median time from diagnosis to transplant was 48 months (6-137 months). MF was primary in 8 and secondary to essential thrombocytosis in 2 patients. According to DIPSS scoring, 1, 2, 5 and 2 patients were low, intermediate-1, intermediate-2 and high risk respectively. Donors were equally distributed between matched related and matched unrelated. Bone marrow was used as the source in all but one patient. Nine patients (90%) had palpable splenomegaly. Six underwent splenectomy of which 1 died of a related complication (sepsis from abscess in the splenic bed). Three received sXRT prior to HSCT with no associated complications. All but one patient (who had a prior splenectomy) engrafted successfully. Median time to engraftment was 18 days (sXRT 18 days, splenectomy 19 days) for neutrophils and 26 days for platelets regardless of splenic therapy. Only 2 patients developed acute grade III-IV GVHD and 1 patient developed extensive chronic GVHD. 4/7 patients with a prior splenectomy were evaluable for disease response. Of these 2 had complete hematologic response, 1 had clinical improvement with eventual relapse, and 1 had progressive disease. Among the 3 patients receiving sXRT, 2 patients had complete hematologic response as well as a spleen response and 1 had stable disease.Three patients were alive at last follow-up. Causes of death included disease relapse (n=2), GVHD (=3) and sepsis (n=2). Cumulative incidence of NRM was 40% at 1 year. Five year OS was estimated at 30%. Discussion: Our data demonstrates that splenic XRT is well tolerated and equivalent to splenectomy in terms of engraftment outcomes and disease response. Survival and GVHD outcomes with PPT conditioning were similar to those reported with other RIC regimens. PPT is a reasonable conditioning regimen for these patients. Further study to optimize timing of HSCT and patient selection to reduce NRM is needed. Disclosures Comenzo: Millennium Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Teva: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.
308 Background: Androgen receptor splice variant 7 (AR-V7) has been shown to confer resistance to androgen receptor signaling inhibitors (ARS-I) such as enzalutamide (enza) and abiraterone (abi). Resistance can be observed at the time of initial treatment, or may be acquired later in the disease course. Prior research has primarily focused on AR-V7 expression in circulating tumor cells (CTCs) but the utility of more affordable immunohistochemical (IHC) testing to predict for primary resistance to ARS-I remains unknown, which is of particular relevance as ARS-I gain use as initial therapy. Methods: We identified patients in the South Texas Veterans Health Administration Tumor Registry with metastatic, castrate-resistant prostate cancer who received ARS-I since 2011. IHC for AR-V7 staining was validated on controls and performed on tissue from the most recent tissue specimen (diagnostic biopsy, prostatectomy, or biopsy of a metastatic site) on all identified patients with adequate tissue available. Results: 25 of 42 (60%) patients receiving abi had PSA response with median duration of response (DOR) of 231 days. 14 of 26 (54%) of patients receiving enza experienced PSA response with a median DOR of 165 days. IHC is currently being interpreted on stored tissue specimens to assess predictive efficacy of AR-V7 staining. The de-novo rate of AR-V7 expression and correlation with response to ARS-I in the veteran population will be reported with final results. Conclusions: IHC testing for AR-V7 may provide a cost-effective biomarker to identify patients resistant to ARS-I, thus avoiding thus avoiding time-consuming and costly treatment with ineffective therapy. Further study is warranted to assess cost-effectiveness and reduction in unnecessary toxicity by the use of IHC testing for AR-V7 in the front-line setting to predict primary resistance for patients that would otherwise qualify for ARS-I.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.