Decision-making tools to assist prognosis and treatment choices in early breast cancer: a review

Sineoculis homeobox homolog 1 protein is associated with breast cancer progression and survival outcome

Sineoculis homeobox homolog 1 (SIX1) is one of the transcription factors that act as master regulators of development and is frequently dysregulated in cancer. This study explores the roles of SIX1 in tumor progression and as a prognostic determinant of breast cancer. Breast cancer specimens from 262 patients were selected for analysis of SIX1 protein by immunohistochemistry (IHC). The localization of SIX1 protein was detected in MDA-MB468 breast cancer cells using immunofluorescence (IF) staining. The survival rates were calculated by the Kaplan-Meier method, and the relationship between prognostic factors and patient survival was also analyzed by the Cox proportional hazard models. SIX1 protein mainly showed cytoplasmic/perinuclear staining pattern in breast cancer using IHC in paraffin embedded breast cancer tissues and IF in MDA-MB468 cancer cells. The strongly positive rate of SIX1 protein was 61.8% (162/262) in breast cancer and 23.1% (12/52) in ductal carcinoma in situ (DCIS), which was significantly higher than adjacent normal breast tissues (6.7%, 3/45). SIX1 overexpression was positively correlated with clinical stage, lymph node metastasis, Her2 expression status, and disease-free survival (DFS) and 5-year overall survival (OS) rates of patients with breast cancer. Moreover, patients with late stage breast cancer and high SIX1 expression had poorer survival rates than those with low SIX1 expression. Further analysis using a Cox proportional hazard regression model revealed that high SIX1 expression emerged as a significant independent hazard factor for the DFS and OS rates of patients with breast cancers along with Her2 status and clinical stage. SIX1 may potentially be used as an independent biomarker for prognostic evaluation of breast cancer.

Biomarkers in the management of breast cancer: great expectations, hard times

Progress in biomarkers research has resulted in increasing awareness of the heterogeneity of breast cancer. The identification of subtypes with different clinical behavior and the possibility of using targeted therapy in specific subgroup of patients (eg, those with tumors overexpressing HER2) raise expectations for increasing personalization of treatment. However, there is a widening gap between scientific discoveries and practical application in everyday practice: too many patients are still being managed based only on traditional clinical and pathologic parameters, because of lack of access to up to date technology-such as gene profiling, or cell proliferation assays-in many cancer centers in the United Kingdom. In this article, we provide some examples of this contrast, drawn from the literature and from our own clinical experience in South West Wales, and discuss possible solutions.

WSG ADAPT - adjuvant dynamic marker-adjusted personalized therapy trial optimizing risk assessment and therapy response prediction in early breast cancer: study protocol for a prospective, multi-center, controlled, non-blinded, randomized, investigator initiated phase II/III trial

BACKGROUND

Adjuvant treatment decision-making based on conventional clinical/pathological and prognostic single molecular markers or genomic signatures is a therapeutic area in which over-/under-treatment are still key clinical problems even though substantial and continuous improvement of outcome has been achieved over the past decades. Response to therapy is currently not considered in the decision-making procedure.ADAPT is one of the first new generation (neo)adjuvant trials dealing with individualization of (neo)adjuvant decision-making in early breast cancer and aims to establish early predictive surrogate markers, e.g., Ki-67, for therapy response under a short induction treatment in order to maximally individualize therapy and avoid unnecessary toxicity by ineffective treatment.

METHODS/DESIGN

The prospective, multi-center, controlled, non-blinded, randomized, investigator initiated phase II/III ADAPT trial has an innovative "umbrella" protocol design. The "umbrella" is common for all patients, consisting of dynamic testing of early therapy response. ADAPT will recruit 4,936 patients according to their respective breast cancer subtype in four distinct sub-trials at 80 trial sites in Germany; 4,000 patients with hormone receptor positive (HR+) and HER2 negative disease will be included in the ADAPT HR+/HER2- sub-trial, where treatment decision is based on risk assessment and therapy response to induction therapy, and 380 patients will be included in ADAPT HER2+/HR+. A further 220 patients will be included in ADAPT HER2+/HR- and 336 patients will be recruited for ADAPT Triple Negative. These three sub-trials focus on identification of early surrogate markers for therapy success in the neoadjuvant setting. Patients will be allocated to the respective sub-trial according to the result of their diagnostic core biopsy, as reported by local/central pathology for HR and HER2 status.

DISCUSSION

Recent trials, such as the GeparTrio, have shown that response-guided therapy using clinical response may improve outcome. For chemotherapy or HER2-targeted treatment, pathologic complete response in a neoadjuvant setting is an excellent predictor of outcome. For endocrine therapy, response to short induction treatment - as defined by decrease in tumor cell proliferation - strongly correlates with outcome. ADAPT now aims to combine static prognostic and dynamic predictive markers, focusing not just on single therapeutic targets, but also on general markers of proliferation and cell death. Biomarker analysis will help to optimize selection of subtype-specific treatment.

TRIAL REGISTRATION

ClinicalTrials.gov: ADAPT Umbrella: NCT01781338; ADAPT HR+/HER2-: NCT01779206; ADAPT HER2+/HR+: NCT01745965; ADAPT HER2+/HR-: NCT01817452; ADAPT TN:NCT01815242.