TAC Versus TC for Adjuvant Breast Cancer

Both TAC (docetaxel, doxorubicin, and cyclophosphamide) and TC (docetaxel and cyclophosphamide) are established adjuvant chemotherapy regimens for early stage breast cancer. TAC, however, due to the inclusion of the anthracycline doxorubicin, carries a high risk of hematologic and cardiotoxic adverse effects. Substantial evidence supports the concept that early stage HER2-negative breast cancers will benefit similarly from anthracycline-based adjuvant and non-anthracycline-based chemotherapy.

Further, approximately 0 to 9% of HER2-negative breast cancers have alterations in the TOP2A gene, which may predict for benefit from anthracycline-based chemotherapy.

We hypothesize that 6 cycles of TC versus 6 cycles of TAC will have similar efficacy in the treatment of early stage HER2-negative breast cancer and that TC will have less toxicity. If this hypothesis were upheld and the anthracycline doxorubicin could be eliminated from the regimen while obtaining similar efficacy in this population of patients, it would not only be an important advance in the understanding of the biology of cancer, but it would also be of significant clinical benefit to women with breast cancer.

Inclusion criteria

A woman will be eligible for inclusion in this study if she meets all of the following criteria:

• Age >18 to <70 years old.
• Has known ER and PR status
• Has HER2 nonamplified disease, confirmed by FISH
• Has known menopausal status (see Section 7.3 for criteria)
• Has operable, histologically confirmed, Stage I, IIA, IIB, or IIIA, IIIB, or IIIC invasive carcinoma of the breast. Bilateral synchronous breast cancer is allowable provided that 1 primary meets the inclusion criteria.
• Meets 1 of the 3 following criteria:

• T1-3N1-3M0 if ER positive or negative
• T2-3N0M0 if ER positive or negative
• T1N0M0 if ER and PR negative
• Has complete surgical resection of the primary breast tumor: either lumpectomy or mastectomy with sentinel lymph node biopsy or axillary dissection, with clear margins for both invasive and ductal carcinoma in situ (DCIS)
• Has had no prior chemotherapy unless >5 years ago
• Has an ECOG Performance Status (PS) 0-1
• Has laboratory values of: See protocol for specific details
• Has aspartate aminotransferase (AST) or alanine aminotransferase (ALT) and alkaline phosphatase (ALP) within the ranges shown below. In determining eligibility the more abnormal of the 2 values (AST or ALT) should be used. See protocol for specific details
• Has normal cardiac function as evidenced by a LVEF >50%, but WNL by institutional standard by multiple gated acquisition (MUGA) scan. An echocardiogram (ECHO) may be used if MUGA is not available, but the same modality must be used consistently throughout the study to evaluate LVEF. Ejection fraction as determined by ECHO must be WNL by institutional standard.
• Has no evidence of metastatic disease outside of breast by physical examination and chest x-ray. Other scans if done as needed by the patient (eg, bone scan; abdominal, chest CT; PET or PET/CT; ultrasound; or MRI should indicate no evidence of metastatic disease
• Has had baseline bilateral mammography
• It has been <84 days since the date of definitive surgery (eg, mastectomy or, in the case of a breast-sparing procedure, axillary dissection) with adequate wound healing, as determined by the Treating Physician
• Has a negative serum pregnancy test within 7 calendar days prior to registration (female patients of childbearing potential [not surgically sterilized and between menarche and 1 year postmenopause])
• If fertile, patient has agreed to use an acceptable method of birth control (barrier contraceptive only) to avoid pregnancy for the duration of the study and for a period of 3 months thereafter
• Has adequate tumor specimen available for FISH analysis of TOP2A status (See Appendix VI).
• Has signed a Patient Informed Consent Form
• Has signed a Patient Authorization Form

Exclusion criteria

A woman will be excluded from this study if she meets any of the following criteria:

• Has any evidence of metastatic disease following surgical resection of the primary tumor including: positive surgical margins, staging work-up, or physical examination suspicious for malignant disease
• Has T4 disease (ie, patients with fixed tumors, peau d'orange skin changes, skin ulcerations, or inflammatory changes)
• Has Stage IV breast cancer (M1 disease on TNM staging system)
• Has a history of severe hypersensitivity reaction to drugs formulated with polysorbate 80
• Has had neoadjuvant chemotherapy for this breast cancer
• Has ever had a myocardial infarction (MI) or has a history of heart failure, uncontrolled angina, severe uncontrolled arrhythmias, pericardial disease, or electrocardiographic evidence of acute ischemic changes
• Is receiving concurrent immunotherapy, hormonal therapy (eg, tamoxifen, hormone replacement therapy), or radiation therapy. Must discontinue prior to registering on the study.
• Is receiving concurrent investigational therapy or has received such therapy within the past 30 calendar days
• Has peripheral neuropathy >Grade 1
• Has had a major organ allograft or condition requiring chronic immunosuppression (ie, kidney, liver, lung, heart, bone marrow transplant, or autoimmune diseases). Patients who have received corneal transplants or cadaver skin or bone transplants are eligible.
• Has a serious uncontrolled intercurrent medical or psychiatric illness, including serious viral (including clinically defined AIDS), bacterial or fungal infection; or history of uncontrolled seizures, or diabetes, or CNS disorders deemed by the Treating Physician to be clinically significant, precluding informed consent
• Has active hepatitis B or hepatitis C with abnormal liver function tests (LFTs) or is known to be HIV positive
• Has a history of other malignancy within the last 5 years (except cured basal cell carcinoma of skin, carcinoma in situ of uterine cervix, DCIS, which could affect the diagnosis or assessment of any of the study drugs
• In an obese patient to whom the Treating Physician would not be comfortable administering full doses of study drugs as calculated by the BSA. Obese patients will be treated based on actual body weight. Obese patients treated with full doses based on actual BSA are eligible.
• Is pregnant or breastfeeding
• Is deemed unable to comply with requirements of study