A Randomized Phase III Post-Operative Trial of Platinum Based Chemotherapy Vs. Capecitabine in Patients with Residual Triple-Negative Breast Cancer following Neoadjuvant Chemotherapy

This randomized phase III trial studies how well cisplatin or carboplatin (platinum based
chemotherapy) works compared to capecitabine in treating patients with remaining (residual)
basal-like triple-negative breast cancer following chemotherapy after surgery (neoadjuvant).
Drugs used in chemotherapy, such as cisplatin, carboplatin and capecitabine, work in
different ways to stop the growth of tumor cells, either by killing the cells, by stopping
them from dividing, or by stopping them from spreading. It is not yet known whether cisplatin
or carboplatin is more effective than capecitabine in treating patients with residual triple
negative basal-like breast cancer.

ELIGIBILITY CRITERIA FOR SCREENING AND MOLECULAR PROFILING (STEP 0)

Inclusion Criteria:

- Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 within 2 weeks
prior to screening

- Female and male patients must have histologically confirmed invasive breast cancer
that meets the following criteria:

- Clinical stage II-III (American Joint Committee on Cancer [AJCC] 7th edition) at
diagnosis, based on initial evaluation by clinical examination and/or breast
imaging; no metastatic disease allowed

- ER- and PR- should meet one of the following criteria:

- =< 10% cells stain positive, with weak intensity score (equivalent to Allred
score =< 3)

- =< 1% cells stain positive, with weak or intermediate intensity score
(equivalent to Allred score =< 3)

- HER2 negative (not eligible for anti-HER2 therapy) will be defined as:

- Immunohistochemistry (IHC) 0, 1+ without in situ hybridization (ISH)
HER2/neu chromosome 17 ratio OR

- IHC 2+ and ISH HER2/neu chromosome 17 ratio non-amplified with ratio less
than 2.0 and if reported average HER2 copy number < 6 signals/cells OR

- ISH HER2/neu chromosome 17 ratio non-amplified with ratio less than 2.0 and
if reported average HER2 copy number < 6 signals/cells without IHC

- NOTE: Patients that originally present with synchronous bilateral tumors are
eligible provided both tumors are TNBC, and at least one of them fulfills
the remainder eligibility criteria of the protocol; multifocal or
multicentric breast cancers are eligible as long as all tumors fulfill
eligibility criteria

- NOTE: Patients that have a discrepancy in ER/PR/HER2 status between original
diagnosis and surgical specimen (if ER/PR/HER2 status were repeated) are not
eligible for study participation (i.e. ER/PR/HER2 has to fulfill above
criteria in both scenarios)

- Patients must have completed neoadjuvant taxane +/- anthracycline; patients must NOT
have received cisplatin or carboplatin or capecitabine as part of their neoadjuvant
therapy regimen

- NOTE: Patients who received preoperative therapy as part of a clinical trial may
enroll

- NOTE: Patients that were not able to complete their planned neoadjuvant
chemotherapy for any reason (i.e. toxicities, etc.) are eligible to participate
as long as no further systemic standard of care therapy is planned by the
treating physician

- Must have completed definitive resection of primary tumor

- Negative margins for both invasive and ductal carcinoma in situ (DCIS) are
desirable, however patients with positive margins may enroll if the treatment
team believes no further surgery is possible and patient has received
radiotherapy; patients with margins positive for lobular carcinoma in situ (LCIS)
are eligible

- Either mastectomy or breast conserving surgery (including lumpectomy or partial
mastectomy) is acceptable

- Sentinel node biopsy either pre or post neoadjuvant chemotherapy (i.e. at the
time of definitive surgery) are allowed; axillary dissection is encouraged in
patients with lymph node involvement, but is not mandatory

- Post neoadjuvant chemotherapy, patients must be found to have residual invasive cancer
in the breast at the time of definitive surgery; residual cancer is defined as a
contiguous focus of residual invasive cancer, in the breast, measuring >= 1 cm in
diameter, and with more than minimal cellularity, as per local pathologist
determination; this is required due to constraints in deoxyribonucleic acid (DNA)
extraction for PAM50 analysis

- NOTE: The presence of ductal carcinoma in situ (DCIS) without invasion does not
qualify as residual invasive disease in the breast

- NOTE: Despite lymph node involvement if residual invasive cancer in the breast is
< 1 cm in diameter patients are not eligible for participation

- Radiotherapy may be given before or after protocol treatment per standard of care
guidelines; when radiotherapy is planned prior to protocol treatment administration,
patients may be registered and screened while receiving radiation

- Post-mastectomy radiotherapy is required for all patients with the following:

- Primary tumor >= 5 cm (prior to neoadjuvant chemotherapy [clinically] or at
the time of definitive surgery) or involvement of 4 or more lymph nodes at
the time of definitive surgery

- For patients with primary tumors < 5 cm or with < 4 involved lymph nodes
prior to neoadjuvant chemotherapy and at the time of definitive surgery,
provision of post-mastectomy radiotherapy is at the discretion of the
treating physician

- Radiation of regional nodal basins is at the discretion of the treating
radiation oncologist

- NOTE: Breast radiotherapy (whole breast or partial) is required for patients who
underwent breast-conserving therapy, including lumpectomy or partial mastectomy

- Hemoglobin (Hgb) > 9.0 g/dL

- Platelets > 100,000 mm^3

- Absolute neutrophil count (ANC) > 1500 mm^3

- Calculated creatinine clearance of > 50 mL/min using the Cockcroft-Gault formula

- Bilirubin =< 1.5 x ULN upper limit of normal (except in patients with documented
Gilbert?s disease, who must have a total bilirubin =< 3.0 mg/dL)

- Aspartate aminotransferase (AST, serum glutamic oxaloacetic transaminase [SGOT]) =<
2.5 x upper limit of normal (ULN)

- Alanine aminotransferase (ALT, serum glutamate pyruvate transaminase [SGPT]) =< 2.5 x
ULN

- Patients with active >= Common Terminology Criteria for Adverse Events (CTCAE) version
(v.) 4 grade 2 neuropathy are ineligible

- Adjuvant chemotherapy after surgery other than that specified in this protocol is not
allowed; luteinizing hormone-releasing hormone (LHRH) agonists and adjuvant
bisphosphonate or denosumab use is allowed

- Patients must have archived formalin-fixed paraffin-embedded (FFPE) tumor tissue
specimen from the residual disease on the definitive surgical specimen available for
PAM50 analysis for stratification

- Tumor tissue specimen from the definitive surgery has been collected and is ready
to ship to the ECOG-American College of Radiology Imaging Network (ACRIN) Central
Biorepository and Pathology Facility (CBPF) within 21 weeks post-surgery

- The Molecular Diagnostics Laboratory (MDL) at MD Anderson Cancer Center will
perform the PAM50 analysis and notify the ECOG-American College of Radiology
Imaging Network (ACRIN) operations office within three (3) weeks of receipt of
the tumor tissue specimen via secure electronic messaging to the ECOG-ACRIN
database; results will not be reported to the submitting institution

- NOTE: Tissue must be submitted any time during screening period, even if patient
is getting radiation

- NOTE: Every effort should be made to submit the tumor tissue specimen to the
ECOG-ACRIN CBPF immediately

Exclusion Criteria:

- History of TNBC invasive breast cancer within 5 years of enrollment, no concurrent
malignancies of any sort

- Clinically significant infections as judged by the treating investigator

ELIGIBILITY CRITERIA FOR RANDOMIZATION (STEP 1):

- No specific timeframe between registration and randomization needs to be observed, as
long as:

- Patients randomized to the chemotherapy arms have their cycle 1/ day 1 (platinum
based or capecitabine) start within 3 weeks (15 working days) following
randomization date

- Randomization occurs no more than 24 weeks from surgery date

- Must have PAM50 analysis by digital mRNA quantitation on the formalin-fixed
paraffin-embedded tumor tissue specimen (FFPE) of the residual disease in the breast
or axilla resected at the time of definitive surgery completed

- ECOG performance status 0 or 1 within 2 weeks prior to randomization

- Radiotherapy may be given before or after protocol treatment. when radiotherapy is
planned prior to protocol treatment administration, patients must have completed
adjuvant radiotherapy >= 2 weeks prior to randomization for protocol therapy, if
applicable

- Patients must have completed treatment with any investigational agent >= 30 days prior
to randomization for protocol therapy, if applicable

- Patients must be randomized within 24 weeks from surgery

- Women must not be pregnant or breast-feeding; all females of childbearing potential
must have a blood test or urine study within 2 weeks prior to randomization to rule
out pregnancy

- A female of childbearing potential is any woman, regardless of sexual orientation
or whether they have undergone tubal ligation, who meets the following criteria:
1) has not undergone a hysterectomy or bilateral oophorectomy; or 2) has not been
naturally postmenopausal for at least 24 consecutive months (i.e., has had menses
at any time in the preceding 24 consecutive months

- Women of childbearing potential and sexually active males must be strongly advised to
use an accepted and effective method of contraception or to abstain from sexual
intercourse for the duration of their participation in the study

- Hemoglobin (Hgb) > 9.0 g/dL

- Platelets > 100,000 mm^3

- Absolute neutrophil count (ANC) > 1500 mm^3

- International normalized ratio (INR) =< 3 (to be done/tested only for subjects on
warfarin)

- Calculated creatinine clearance of > 50 mL/min using the Cockcroft-Gault formula

- Bilirubin =< 1.5 x ULN (except in patients with documented Gilbert?s disease, who must
have a total bilirubin =< 3.0 mg/dL)

- Aspartate aminotransferase (AST, SGOT) =< 2.5 x ULN

- Alanine aminotransferase (ALT, SGPT) =< 2.5 x ULN