Anne O’Neill

Myeloid suppressor cells with high arginase activity are found in tumors and spleen of mice with colon and lung cancer. These cells, described as macrophages or immature dendritic cells, deplete arginine and impair T cell proliferation and cytokine production. Although arginase activity has been described in cancer patients, it is thought to originate from tumor cells metabolizing arginine to ornithine needed to sustain rapid cell proliferation. The goal of this study was to determine whether myeloid suppressor cells producing high arginase existed in renal cell carcinoma patients. Peripheral blood mononuclear cells from 123 patients with metastatic renal cell carcinoma, prior to treatment, were found to have a significantly increased arginase activity. These patients had a markedly decreased cytokine production and expressed low levels of T cell receptor CD3zeta chain. Cell separation studies showed that the increased arginase activity was limited to a specific subset of CD11b+, CD14-, CD15+ cells with a polymorphonuclear granulocyte morphology and markers, instead of macrophages or dendritic cells described in mouse models. Furthermore, these patients had low levels of arginine and high levels of ornithine in plasma. Depletion of the CD11b+, CD14- myeloid suppressor cells reestablished T cell proliferation and CD3zeta chain expression. These results showed, for the first time, the existence of suppressor myeloid cells producing arginase in human cancer patients. In addition, it supports the concept that blocking arginase may be an important step in the success of immunotherapy.

PURPOSE: Chemotherapy, tamoxifen, and ovarian ablation/suppression (OA/OS) are effective adjuvant approaches for premenopausal, steroid hormone receptor-positive breast cancer. The value of combined therapy has not been clearly established. PATIENTS AND METHODS: Premenopausal women with axillary lymph node-positive, steroid hormone receptor-positive breast cancer (1,503 eligible patients) were randomly assigned to six cycles of cyclophosphamide, doxorubicin, and fluorouracil (CAF), CAF followed by 5 years of monthly goserelin (CAF-Z), or CAF followed by 5 years of monthly goserelin and daily tamoxifen (CAF-ZT). The primary end points were time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS) for CAF-Z versus CAF, and CAF-ZT versus CAF-Z. RESULTS: With a median follow-up of 9.6 years, the addition of tamoxifen to CAF-Z improved TTR and DFS but not OS. There was no overall advantage for addition of goserelin to CAF. CONCLUSION: Addition of tamoxifen to CAF-Z improves outcome for premenopausal node-positive, receptor-positive breast cancer. The role of OA/OS alone or with other endocrine agents should be studied more intensely.

Importance: Late recurrence 5 or more years after diagnosis accounts for at least one-half of all cases of recurrent hormone receptor-positive breast cancer. Objective: To determine whether the presence of circulating tumor cells (CTCs) in a peripheral blood sample obtained approximately 5 years after diagnosis was associated with late clinical recurrence of operable human epidermal growth factor receptor 2-negative breast cancer. Design, Setting, and Participants: This per-protocol secondary analysis of the Double-Blind Phase III Trial of Doxorubicin and Cyclophosphamide Followed by Paclitaxel With Bevacizumab or Placebo in Patients With Lymph Node Positive and High Risk Lymph Node Negative Breast Cancer enrolled patients from 2007 to 2011 who were without clinical evidence of recurrence between 4.5 and 7.5 years after primary surgical treatment of human epidermal growth factor receptor 2-negative stage II-III breast cancer followed by adjuvant systemic therapy. Patients were enrolled in a subprotocol for secondary analysis from February 25, 2013, to July 29, 2016, after signing consent for the subprotocol. The analysis was performed in April 2018. Interventions: A blood sample was obtained for identification and enumeration of CTCs. Main Outcome and Measures: The association between a positive CTC assay result (at least 1 CTC per 7.5 mL of blood) and clinical recurrence. Results: Among 547 women included in this analysis, the results of the CTC assay were positive for 18 of 353 with hormone receptor-positive disease (5.1% [95% CI, 3.0%-7.9%]); 23 of 353 patients (6.5% [95% CI, 4.2%-9.6%]) had a clinical recurrence. The recurrence rates per person-year of follow-up in the CTC-positive and CTC-negative groups were 21.4% (7 recurrences per 32.7 person-years) and 2.0% (16 recurrences per 796.3 person-years), respectively. In multivariate models including clinical covariates, a positive CTC assay result was associated with a 13.1-fold higher risk of recurrence (hazard ratio point estimate, 13.1; 95% CI, 4.7-36.3). Seven of 23 patients (30.4% [95% CI, 13.2%-52.9%]) with recurrence had a positive CTC assay result at a median of 2.8 years (range, 0.1-2.8 years) before clinical recurrence. The CTC assay result was also positive for 8 of 193 patients (4.1% [95% CI, 1.8%-8.0%]) with hormone receptor-negative disease, although only 1 patient (0.5% [95% CI, 0%-2.9%]) experienced disease recurrence (this patient was CTC negative). Conclusions and Relevance: A single positive CTC assay result 5 years after diagnosis of hormone receptor-positive breast cancer provided independent prognostic information for late clinical recurrence, which provides proof of concept that liquid-based biomarkers may be used to risk stratify for late recurrence and guide therapy. Trial Registration: ClinicalTrials.gov identifier: NCT00433511.