Trial Information

MIRNA Profiling of Breast Cancer in Patients Undergoing Neoadjuvant or Adjuvant Treatment for Locally Advanced & Inflammatory Breast Cancer

Current neoadjuvant or adjuvant treatment strategies do not allow for rationale
incorporation of such agents. One needs tools to predict both de novo and acquired
resistance to therapeutic agents. This is a difficult task, due to the compound nature of
escape routes: tumor exposure is usually to a combination of therapeutic agents and the
mechanisms of resistance are broad: intrinsic resistance due to existing mutations, or
regulatory - miRNA, other epigenetic - alterations, polymorphisms, tumor cell adaptation
via new mutations and activation of alternative pathways, lack of optimal
pharmacokinetics/genomics, activation of efflux mechanisms, accelerated repair mechanisms
are involved.

Similarly, not all patients who are candidates for primary surgical intervention to be
followed by post-operative adjuvant therapy benefit from such systemic treatments. The
mechanisms of resistance be it de novo in surviving stem cell/tumorigenic components, or
acquired by cells left behind "dormant" after the surgical intervention, are not well
delineated.

Breast tumors subjected to neoadjuvant chemotherapy allow for baseline and
treatment-effected sampling. Characterization of core biopsy specimens of primary tumors
procured prior to exposure to neoadjuvant therapy from different varieties of breast cancer
subtypes, and of subsequent mid-treatment and intraoperative (procured during definitive
surgery following completion of neoadjuvant therapy) samples should help to assess the
predictive value of the pre-treatment and post-treatment miRNA expression profile for
complete and near complete response, as a surrogate marker for survival. Similarly,
patterns of de novo and acquired resistance may emerge when assessment of pre- and post
treatment miRNA expression profiles are analyzed in a supervised manner of classification
using pathological response as classifier. Samples obtained from patients with primary
surgical removal of their tumors before any systemic treatment exposure on the other hand,
will allow for determining markers of prognosis, and predictors for response to therapeutic
targeting agents.

Time Perspective: Retrospective/Prospective