Abstract 3534
Background
Patients (pts) with advanced neuroendocrine tumors (NET) represent an unmet medical need, what motivates the development of new treatments. Prior retrospective study conducted by our group showed that among 96 NET, immunohistochemistry (IHC) expression for estrogen (ER) and progesterone receptors (PR) were observed in 20.8% and 18.8% of cases, respectively. Additionally, an old clinical trial (Mortel C, 1984) suggested antitumor effects of estrogen/progesterone-directed therapies in NET pts. Yet the effects of an antiestrogen agent in NET pts whose tumor express ER and/or PR are unknown. Hence we will conduct a clinical trial to test the efficacy of tamoxifen in ER/PR positive NET pts.
Trial design
Single-arm phase II multicenter trial of tamoxifen 20mg PO continuously until intolerance and/or tumor progression. Eligible pts must be ≥ 18 years old, have histologically confirmed advanced, irresectable well-differentiated lung or gastroeteropancreatic NET, IHC expression of ER and/or PR ≥ 1%, documented progression in the prior 12 months, measurable disease, prior treatments with standard therapies and/or no indication to start new treatment due to lack of access, risk of toxicities or without clinical indication (patients who meet criteria for watchful waiting may be included), ECOG 0-2, adequate organ function. Main exclusion criteria are: aggressive disease requiring cytotoxic therapy, use of oral anticoagulants, previous history of deep vein thrombosis or pulmonary embolism in the last 12 months, postmenopausal vaginal bleeding with no defined etiology. The primary endpoint is disease control rate (DCR) at week 24 as per RECIST 1.1. Secondary endpoints are progression-free survival, biochemical response, response rate. Exploratory evaluations: circulating tumor cells kinetics (qualitative and quantitative) and PET-CT gallium-68 intake intensity variation (at baseline and at week 24). Sample size assumptions: the H0 is DCR at week 24 of 50% and H1, 70%; with a type I error of 10%, power of 80% and attrition rate of 30%, the final sample size will be 22 pts.
Clinical trial identification
NCT03870399.
Editorial acknowledgement
Legal entity responsible for the study
Rachel Riechelmann.
Funding
AC Camargo Cancer Center.
Disclosure
M. Barros: Honoraria (self): Novartis. J.F. Rego: Honoraria (self): Novartis. R.P. Riechelmann: Honoraria (self): Novartis. All other authors have declared no conflicts of interest.
Resources from the same session
3608 - Prognostic impact of Body Mass Index (BMI) on overall survival in patients with metastatic breast cancer
Presenter: Khalil SALEH
Session: Poster Display session 2
Resources:
Abstract
2686 - Clinicopathological characteristics, survival and prognostic factors of breast cancer-related microangiopathic haemolytic anemia: a multicenter study
Presenter: Marion Alhenc Gelas
Session: Poster Display session 2
Resources:
Abstract
1565 - Metabolic tumor volume by 18F-FDG PET/CT is an independent prognostic factor in metastatic breast cancer
Presenter: Heekyung Ahn
Session: Poster Display session 2
Resources:
Abstract
4498 - Patient Preferences for breast cancer treatments: A Discrete Choice Experiment from four European countries
Presenter: Thomais Konstantopoulou
Session: Poster Display session 2
Resources:
Abstract
1423 - Palbociclib plus fulvestrant as second- or later-line therapy for patients with locally advanced, inoperable or metastatic HR+/HER2- breast cancer in Germany: Interim results of the INGE-B phase 2 study
Presenter: Diana Lüftner
Session: Poster Display session 2
Resources:
Abstract
2284 - Ventriculoperitoneal Shunt for CNS Metastasis in Breast Cancer: Clinical Outcomes Based on Intrinsic Subtype
Presenter: Hee Kyung Kim
Session: Poster Display session 2
Resources:
Abstract
4598 - Administration of chemotherapy for metastatic breast cancer near the end of life: a population registry study
Presenter: Luisa Edman Kessler
Session: Poster Display session 2
Resources:
Abstract
5706 - Prognostic value of histological growth pattern in patients operated for breast cancer liver metastases
Presenter: Ali Bohlok
Session: Poster Display session 2
Resources:
Abstract
1697 - Illness perceptions, quality of life and mood in metastatic breast cancer patients
Presenter: Isabel Domingues
Session: Poster Display session 2
Resources:
Abstract
1935 - Multidisciplinary Treatments Increases Overall Survival in Patients with Newly Diagnosed Stage IV Breast Cancer:An Analysis of 2010–2014 SEER Data
Presenter: Jian Zhang
Session: Poster Display session 2
Resources:
Abstract