Circulating miRNAs: Novel Breast Cancer Biomarkers and Their Use for Guiding and Monitoring Response to Chemotherapy
1. To identify a panel of miRNAs, detectable in the circulation, which are altered in
breast cancer patients
2. To identify specific combinations of miRNAs ('signatures') which associate with breast
cancer intrinsic subtypes, and thereby could aid in prognostication and treatment
planning on an individual patient basis.
1. To determine if systemic miRNA analysis can be used as a biomarker for monitoring
response to chemotherapy, in the neoadjuvant setting and in patients who present with breast
cancer recurrence and are treated with upfront chemotherapy
This is a prospective cohort studies, involving two study cohorts:
Cohort 1: Newly diagnosed breast cancer patients, Cohort 2: Recurrent breast cancer patients
- 1st (baseline) blood sample at presentation before commencing neoadjuvant (cohort 1) or
systemic (cohort 2) treatment.
- 2nd blood sample midway through their chemotherapy treatment (after 2nd cycle if they
are enrolled in a 4 cycle regimen, or after 4th cycle if they are prescribed an 8 week
- 3rd blood sample post-chemotherapy and before surgery (if applicable).
- 4th blood sample 2-4 weeks after surgery, or after last blood sampling if surgery is
- 5th blood sample 12-18 month after surgery or after 3rd blood sampling if surgery is
GUH only: Tissue samples will be taken at time of biopsy and/or at time of surgery.
All samples will be processed for miRNA quantification - a panel of 9 cancer-specific miRNAs
will be measured in each sample, and the change in each patient's miRNA expression levels
monitored over the course of their treatment.
Blood samples will be processed for miRNA analysis, which involves:
1. Lysis using Trizol
2. RNA isolation
3. Assessing concentration and integrity of RNA using Nanodrop spectrophotometry
4. cDNA synthesis (using miRNA specific stem loop primers)
5. PCR amplification and relative quantification (using miRNA specific probes)
Observational Model: Cohort, Time Perspective: Prospective
Relationship between changes in a patients circulating miRNA expression levels over the course of their systemic therapy, and their response to that treatment.
Patients' response to treatment will be determined using 3 standard parameters: clinical, radiological and pathological responses.
up to week 66-92
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