To learn whether certain blood and imaging tests can show which people with early-stage TNBC may already have had a complete response to chemotherapy before they go to surgery.

Primary Objectives To determine the rate of pCR in participants with high-risk, early-stage TNBC who have no residual enhancement on MRI and undetectable ctDNA after receiving neoadjuvant pembrolizumab plus carboplatin plus paclitaxel and proceed with surgery without receiving doxorubicin and cyclophosphamide in the neoadjuvant setting

Inclusion Criteria

• Participants must be 18 years of age or older, able to understand and give written informed consent.

• Histologically proven TNBC, defined as ER ≤10%, PR ≤10%, and HER2 negative based on the 2023 ASCO/CAP guidelines.

• Clinical stage T1cN1-2 or T2-4N0-2 TNBC according to the primary tumor-regional lymph node anatomic staging criteria of the American Joint Committee on Cancer (AJCC), 8th edition.

• Medically eligible to receive immunotherapy in combination with chemotherapy as part of standard of care

• Willingness to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation. (Refer to Pregnancy Assessment Policy MD Anderson Institutional Policy # CLN1114). This includes all female Participants, between the onset of menses (as early as 8 years of age) and 55 years unless the Participant presents with an applicable exclusionary factor which may be one of the following:

  • Postmenopausal (no menses greater than or equal to 12 consecutive months).
  • History of hysterectomy or bilateral salpingo-oophorectomy.
  • Ovarian failure (Follicle Stimulating Hormone and Estradiol in menopausal range, who have received Whole Pelvic Radiation Therapy).
  • History of bilateral tubal ligation or another surgical sterilization procedure.

• Approved methods of birth control are as follows: Hormonal contraception (i.e. birth control pills, injection, implant, transdermal patch, vaginal ring), Intrauterine device (IUD), Tubal Ligation or hysterectomy, Subject/Partner post vasectomy, Implantable or injectable contraceptives, and condoms plus spermicide. Not engaging in sexual activity for the total duration of the trial and the drug washout period is an acceptable practice; however periodic abstinence, the rhythm method, and the withdrawal method are not acceptable methods of birth control. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately.

• Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study participation, and 4 months after completion of study.

• Eastern Cooperative Oncology Group (ECOG) performance status 0-2

• No active viral hepatitis (hepatitis B or C) at baseline

Exclusion Criteria

• Stage IV (metastatic) breast cancer
• History of any prior (ipsi- or contralateral) invasive breast cancer. Note: Prior DCIS is allowed.
• History of other malignancies within the last 5 years except for appropriately treated carcinoma in situ of the cervix, nonmelanoma skin carcinoma, stage I uterine cancer, or other non-breast malignancies with an outcome similar to those mentioned above.
• Prior excisional biopsy of the primary invasive breast cancer.
• Participants with cognitive impairment/psychiatric illness/social situations that would limit compliance with study requirements.
• Participants not medically eligible for chemotherapy with taxanes, carboplatin, and/or anthracycline-based chemotherapy regimens
• Participants not medically eligible for immunotherapy
• Pregnant women are excluded from this study because of the potentially detrimental effect of magnetic resonance imaging on the fetus.