Purpose: Bone marrow-derived progenitor cells, including VEGFR2þ endothelial progenitor cells (EPCs) and copper-dependent pathways, model the tumor microenvironment. We hypothesized that copper depletion using tetrathiomolybdate would reduce EPCs in high risk for patients with breast cancer who have relapsed. We investigated the effect of tetrathiomolybdate on the tumor microenvironment in preclinical models. Experimental Design: Patients with stage II triple-negative breast cancer (TNBC), stage III and stage IV without any evidence of disease (NED), received oral tetrathiomolybdate to maintain ceruloplasmin (Cp) between 8 and 17 mg/dL for 2 years or until relapse. Endpoints were effect on EPCs and other biomarkers, safety, event-free (EFS), and overall survival (OS). For laboratory studies, MDA-LM2-luciferase cells were implanted into CB17-SCID mice and treated with tetrathiomolybdate or water. Tumor progression was quantified by bioluminescence imaging (BLI), copper depletion status by Cp oxidase levels, lysyl oxidase (LOX) activity by ELISA, and collagen deposition.Results: Seventy-five patients enrolled; 51 patients completed 2 years (1,396 cycles). Most common grade 3/4 toxicity was neutropenia (3.7%). Lower Cp levels correlated with reduced EPCs (P ¼ 0.002) and LOXL-2 (P < 0.001). Two-year EFS for patients with stage II-III and stage IV NED was 91% and 67%, respectively. For patients with TNBC, EFS was 90% (adjuvant patients) and 50% (stage IV NED patients) at a median follow-up of 6.3 years, respectively. In preclinical models, tetrathiomolybdate decreased metastases to lungs (P ¼ 0.04), LOX activity (P ¼ 0.03), and collagen crosslinking (P ¼ 0.012).Conclusions: Tetrathiomolybdate is safe, well tolerated, and affects copper-dependent components of the tumor microenvironment. Biomarker-driven clinical trials in high risk for patients with recurrent breast cancer are warranted.
Three-hundred male alcoholics were selected from consecutive admissions to hospital. They were divided into three diagnostic sub-groups: primary alcoholics; alcoholics with unipolar affective disorder; and alcoholics with bipolar affective disorder. After three follow-up interviews over a 2-year period after hospital discharge, the three sub-groups reported differences in frequency of mood change, amount of treatment received, and hospital attendance, although there were no clear-cut differences in items associated with their alcoholism. There were, however, some indications that bipolar patients functioned at a better level during the follow-up period, particularly those who were older, had a previous history of longer periods of abstinence, and maintained more frequent contact with Alcoholics Anonymous (AA) and their family doctor.
Tetrathiomolybdate (TM) is a novel, copper-depleting compound associated with promising survival in a phase II study of patients with high-risk and triple-negative breast cancer. We sought to elucidate the mechanism of TM by exploring its effects on collagen processing and immune function in the tumor microenvironment (TME). Using an exploratory cohort, we identified markers of collagen processing (LOXL2, PRO-C3, C6M, and C1M) that differed between those with breast cancer versus controls. We measured these collagen biomarkers in TM-treated patients on the phase II study and detected evidence of decreased collagen cross-linking and increased degradation over formation in those without disease compared to those who experienced disease progression. Preclinical studies revealed decreased collagen deposition, lower levels of myeloid-derived suppressor cells, and higher CD4+ T-cell infiltration in TM-treated mice compared with controls. This study reveals novel mechanisms of TM targeting the TME and immune response with potential applications across cancer types.
2557 Background: The tumor microenvironment (TME) plays a critical role in the spread of tumors. Bone marrow derived VEGFR2+endothelial progenitor cells (EPCs) and copper-dependent lysyl oxidase (LOX) are key in tumor progression. We hypothesized TM-associated copper depletion inhibits tumor metastases by reducing the number of EPCs and other copper dependent (CD) processes in the pre-metastatic niche. These results are an update with longer follow-up. Methods: Phase II study of BC pts at high risk for recurrence, defined as node+ triple negative (TNBC), stage 3 and 4 with no evidence of disease (NED) were enrolled on a trial of CD with TM. Ceruloplasmin (Cp) levels were maintained between 8-16 mg/dl for two years with an extension phase or until relapse. The primary endpoint was change in EPCs measured by flow cytometry before and during treatment. Secondary endpoints included tolerability, safety, PFS and LOXL-2 levels. Results: 75 pts received 2650 cycles of TM on primary and extension study. The median age is 51 years (range 29-66). Forty-five pts have stage 2/3 BC and 30 with stage 4 NED. TNBC pts were 48% and 40% of pts are stage 4 NED. Median Cp level decreased from 28 to 16 (p < 0.0001) after one cycle. Copper depletion was most efficient in TNBC where Cp levels dropped from 23.5 to 13 after one cycle. TM was well tolerated with grade 3/4 toxicities including: reversible neutropenia (2.3%), febrile neutropenia (0.04%), fatigue (0.2%). Five-year analysis showed a decrease in EPC’s (p = 0.004) and LOXL-2 (p < 0.001). At a median follow-up of 6.9 years, the EFS for 75 pts is 75.6%. PFS for 36 pts with TNBC is 79.2%. EFS for stage 2/3 TNBC is 90% and for stage IV TNBC is 66.7%. Conclusions: TM is safe, well tolerated and appears to affect multiple components of the TME creating an inhospitable environment for tumor progression especially in high risk patients such as TNBC. Randomized trials are warranted, especially in patients at high risk for relapse. Clinical trial information: UL1TR000457.
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