Assessment of Prognostic and Therapeutic Factors in Male Breast Cancer: An Observational Study of a Southwest Spanish Single Center

Background: Male breast cancer (MBC) accounts for less than 1% of breast cancer, requiring extrapolation of results from studies in women. The aim of the study is to evaluate prognostic and therapeutic factors with special focus in endocrine treatment (ET) on the disease outcome.Methods: Observational, retrospective, single-center study of 53 MBC treated between January 1997 and December 2018 participated in the study. Among the participants, 48 patients had a performance status (PS) 0-1 (91%), 48 were hormone-receptor-positive (91%) and 4 were human epidermal growth factor 2 receptor (HER2) positive (8%). A total of 45 patients (85%) were treated with ET, with 36 patients (68%) receiving treatment in an adjuvant setting. The association analysis was performed using Chi-square test and survival was estimated using Kaplan-Meier with SPSS v25. Results: The cohort had a median age of 68 years old (range: 40-88). We found that 84% had a non-metastatic breast cancer. A breast cancer gene (BRCA) analysis was carried out in 43% of the patients, showing BRCA2 mutated in 26.1% of those analyzed, without obtaining a benefit in overall survival (P=0.698). The analysis showed higher 5-year overall survival (OS) for PS 0 (P=0.010), absence of vascular invasion (P=0.033), Ki67 ?14% (P=0.041) and absence of metastasis at diagnosis (p<0.0001). Patients receiving adjuvant ET above 5 years had a longer median OS (89 vs 69.6 months, P=0.024), disease-free survival (DFS), and distant relapse (84 vs 48 months; P=0.005, and P=0.002, respectively).Conclusions: Several prognostic factors for male breast cancer have been described. Noteworthy, patients receiving adjuvant ET above 5 years had a higher OS and DFS. BRCA did not show prognostic value in OS in this cohort. Further studies with larger sample size are necessary.

Circulating LncRNAs as predictive biomarkers by molecular subtypes in advanced breast tumors

e23041

Background: Breast cancer is the most common malignant tumor in women worldwide. The leading breast cancer deaths are due to advanced disease stage. For this reason, identification of novel breast cancer progression-associated biomarkers would enhance the clinical management of each patient. Long non-coding RNAs (LncRNAs) are defined as noncoding RNAs longer than 200 nucleotides and are involved in several regulatory processes, such as regulation of gene expression. Moreover, it has been described that LncRNA expression is deregulated in different human diseases such as breast cancer. However, it is unclear if circulating LncRNAs could be used as progression biomarkers of breast cancers. The purpose of this study was to evaluate the role of circulating LncRNAs in patients with advanced breast cancer. Methods: Expression of 84 LncRNAs was quantified by “RT2 IncRNA PCR Array Human Cancer PathwayFinder” (Qiagen) in plasma from 24 subjects (12 patients with advanced breast cancer and 12 healthy subjects). cDNAs were pooled into four groups, two groups containing a mixture of six patients with advanced breast cancer and another two groups containing a mixture of six cDNAs from healthy subjects. Three differentially expressed LncRNAs were selected for validation by specific real-time PCR assay. Results: Three deregulated LncRNAs were identified and validated in patients with advanced breast cancer versus healthy subjects. We found that LncRNAs GAS5 and ZFAS1 expression was decreased in the Luminal, Her2-positive and Triple Negative advance cancer groups compared to healthy subjects. In contrast, LncRNA RMRP expression was increased in Luminal and Her2-positive advance cancer groups. To our knowledge, there are no publications relating the LncRNA RMRP expression with advance breast cancer research. Conclusions: These results contribute to unreveal the role of circulating LncRNAs as biomarkers in the advanced breast cancer and provide novel non-invasive tools in this disease.

A phase II trial to assess the activity and safety of the hypoxia-activated prodrug evofosfamide (TH-302) in combination with sunitinib in patients with disseminated grade 1 and 2 pancreatic neuroendocrine tumors (pNET) as a first-line approach: The GETNE-1408 trial

TPS479

Background: Pancreatic-NETs are highly vascular tumors. The anti-angiogenetic sunitinib was approved in advanced pNETs based on prolongation of progression-free survival. Upregulation of several proangiogenic factors that reflects intratumor hypoxia conditions might drive resistance to sunitinib in pNETs. Evofosfamide is a prodrug that under hypoxic conditions preferentially releases a brominated version of isophosphoramide mustard and has shown activity in cell lines from neural crest derived tumors such as melanoma and glioblastoma/astrocytoma. We hypothesize that evofosfamide may have activity in the pathologic hypoxic conditions present in the tumor environment of neuroendocrine tumors inducing responses that may be consolidated and prolonged with sunitinib in patients with advanced pNETs that are naïve for systemic treatment. Methods: This is a prospective, non randomized, open-label, phase II study that is being conducted in 10 university sites belonging to the Spanish Task Force Group for NETs (GETNE) in Spain. Patients with histologically proven diagnosis of progressive unresectable or metastatic pNET with Ki67 < 20% and grade 1 or 2 will receive sunitinib orally at 37.5 mg PO daily on days 1 to 28 of a 28-day cycle (4 weeks) plus evofosfamide administered at 340 mg/m2 by IV infusion over 30-60 minutes on Days 8, 15 and 22 of a 28-day cycle (4 weeks). Hypoxia-related tumor markers, single nucleotide polymorphisms related to activity and metabolism of antiangiogenic agents (VEGFR2, VEGFR3, PDGFR-α, VEGF-A, IL8, CYP3A4, CYP3A5, ABCB1-2) will be correlated with clinical outcome. In this study it is planned to include 43 patientsbased on a two-stage Simon’s phase II design (α = 0.05, β = 80%). If the trial shows 8 responses or more among 43 patients, the treatment will be considered for further investigation. EudraCT number: 2014-004072-30 Clinical trial information: NCT02402062.

Proof-of-concept study of Sym004, an anti-EGFR monoclonal antibody (mAb) mixture, in patients (pts) with anti-EGFR mab-refractory KRAS wild-type (wt) metastatic colorectal cancer (mCRC)

3551

Background: KRAS wt mCRC pts progressing on chemotherapy and anti-EGFR mAbs have limited treatment options. Sym004 is a first-in-class drug mixture of two mAbs targeting non-overlapping epitopes on the EGFR, causing its internalization and degradation. With this unique mechanism of action, Sym004 overcomes acquired resistance to anti-EGFR mAbs in preclinical studies. Methods: Open-label, multicenter trial assessing safety (primary endpoint) and efficacy of 2 dose levels of Sym004 in KRAS wt mCRC pts with prior clinical benefit to anti-EGFR mAbs and subsequent progression during or within 6 months after treatment cessation. Sym004 was administered until disease progression or unacceptable toxicity. Tumor responses were evaluated centrally according to RECIST criteria. Paired skin and tumor biopsies were obtained at baseline and week 4. Results: In total, 42 pts were enrolled at 9 mg/kg (13) and 12 mg/kg (29). Median age was 66 years and median number of prior treatment lines 3. Central radiology review was performed in 12/13 (92%) pts at 9 mg/kg and 27/29 (93%) pts at 12 mg/kg. Tumor shrinkage > 10% was documented in 4/12 (33%) pts at 9 mg/kg, with partial response (PR) in 1/12 (8%) and stable disease (SD) in 9/12 (75%). At 12 mg/kg, 7/27 (26%) pts had > 10% tumor shrinkage, with PR in 3/27 (11%) and SD in 15/27 (56%). Median progression-free survival was 13.6 weeks (95% CI: 5.3-23) and 13.7 weeks (95% CI: 5.9-18.6), respectively. Duration of response for pts with PR was 5.6-17.6 weeks. Grade 3 or higher toxicity included skin rash in 26/42 (62%), hypomagnesemia in 16/42 (38%) and diarrhea in 2/42 (8%). Adverse events were manageable with dose reduction and supportive medication. There were no indications of immunogenicity. Pharmacodynamic analysis in serial tumor samples showed profound down-regulation of EGFR and reduction in proliferation marker Ki67. Conclusions: Sym004 at weekly doses of 9 and 12 mg/kg showed significant clinical activity in anti-EGFR treatment-refractory KRAS wt mCRC pts, clearly demonstrating proof-of-concept. Serial biopsies confirmed its mechanism of action. No unexpected adverse events were observed. Clinical trial information: NCT01117428.