Breast-Specific Gamma Imaging and Locally Advanced Breast Cancer Undergoing Neoadjuvant Chemotherapy

A prospective cohort study design will be conducted. Patients with LABC who receive chemotherapy will undergo physical examination, ultrasound, MRI, and BSGI at baseline, midway, and at the completion of chemotherapy. Approximately 100 patients will be recruited over a 2-year period. This study will give clinicians further insight into the usefulness of ultrasound, MRI, and BSGI in monitoring treatment responses in patients with LABC. This could potentially lead to changes in clinical management of these patients.

Locally advanced breast cancer (LABC) is usually treated with neoadjuvant chemotherapy followed by surgery. At present, monitoring of tumor responses to chemotherapy is primarily carried out using physical examination at the beginning of each chemotherapy cycle. Differentiating viable tumor tissue from inflammation or fibrotic scar tissue can be difficult. There is a growing body of evidence that newer imaging techniques such as positron emission tomography (PET) and magnetic resonance imaging (MRI) may be better at determining whether or not the tumor is actually shrinking, but their sensitivity and specificity were not ideal. Breast-specific gamma imaging (BSGI) using 99mTcsestamibi is a relatively new nuclear medicine imaging technique for breast tumor detection. BSGI shows higher sensitivity than conventional scintimammography in the detection of small breast cancer lesions owing to its high resolution. BSGI is a useful complementary tool to ultrasound, mammography and MRI in breast cancer diagnosis, especially in dense breasts and multifocal or multicentric disease; however, little is known about the ability of BSGI to predict of clinical and pathological response to neo-adjuvant chemotherapy in patients with locally advanced breast cancer. The purpose of this study is to determine the sensitivity and specificity of BSGI in evaluating tumor responses to chemotherapy in patients with LABC and compare this with physical examination, ultrasound, mammography and MRI, which is the current conventional standard of care. A prospective cohort study design will be conducted. Patients with LABC who receive chemotherapy will undergo physical examination, ultrasound, MRI, and BSGI at baseline, midway, and at the completion of chemotherapy. Approximately 100 patients will be recruited over a 2-year period. This study will give clinicians further insight into the usefulness of ultrasound, MRI, and BSGI in monitoring treatment responses in patients with LABC. This could potentially lead to changes in clinical management of these patients.

Eligibility Criteria:
Inclusion Criteria

* 18 Years and older, and histologic proof of breast cancer (invasive ductal or lobular carcinoma-not breast sarcoma or lymphoma)
* Patients having a clinical diagnosis of locally advanced breast cancer (T3 or T4, or N2 according to TNM classification) including inflammatory breast cancer.
* Patients must be able to undergo neoadjuvant chemotherapy.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2 sufficient to undergo chemotherapy

Exclusion Criteria

* Previously treated cancer other than non melanotic skin cancer or carcinoma in situ of the cervix, unless disease-free for 5 years or greater.
* Evidence of metastatic disease (found on chest X-ray, liver ultrasound or bone scan).
* Previous chemotherapy or hormonal therapy for breast cancer.
* Active infection or other significant illnesses which could hamper their ability to tolerate chemotherapy
* Significant concurrent medical problems (e.g. uncontrolled diabetes, active cardiac disease, severe chronic obstructive pulmonary disease) making the patient unfit for surgery.
* Any condition that could interfere with their ability to provide informed consent such as dementia or severe cognitive impairment.
* Pregnant or lactating females.
* Inadequate hematologic, renal and liver function as measured by CBC (WBC\<4.0 x 109, Hb\<100 g/L, plt count\<100 x 109), and abnormal hepatic transaminases (AST, ALT, GGT, alkaline phosphatase\>2x normal), elevated total bilirubin, and elevated serum creatinine (Cr\>110 micromol/L).
* Any contraindication to undergoing MRI or BSGI.