# Challenges in the management of operable triple-negative breast cancer in a survivor of the B-cell acute lymphoblastic leukemia: a case report

## TL;DR

This case report discusses the complex treatment of a young woman with operable triple-negative breast cancer who previously had leukemia and a stem cell transplant.

## Contribution

The paper presents a unique case highlighting challenges in treating TNBC in patients with a history of leukemia and allo-SCT.

## Key findings

- The patient achieved a pathologic complete response with neoadjuvant chemotherapy including carboplatin.
- A pathogenic variant in the PALB2 gene was identified despite challenges from donor cell contamination.
- The case emphasizes the need for tailored treatment and follow-up for TNBC in patients with prior leukemia.

## Abstract

Operable triple-negative breast cancer (TNBC) is an unfavorable subtype of breast cancer, which usually requires an aggressive perioperative systemic treatment. When TNBC presents as a second primary cancer after cured acute leukemia, its management might be challenging.

We present a case report of a young postmenopausal woman with an operable TNBC who had a history of the B-cell acute lymphoblastic leukemia (B-ALL) and graft versus host disease (GVHD) after allogeneic stem cell transplantation (allo-SCT). A history of previous treatment with anthracyclines and radiotherapy and GVHD limited the use of doxorubicin for treatment of her TNBC. Due to the history of GVHD, perioperative treatment with pembrolizumab was omitted. Genetic testing was challenging due to the possible contamination of her tissues with the donor’s cells after allo-SCT. In samples of our patient’s buccal swab, peripheral blood, and tumor tissue, a pathogenic variant in the partner and localizer of BRCA2 (PALB2) gene was found. With neoadjuvant chemotherapy which included carboplatin, a pathologic complete response was achieved. Although our patient has a low risk for recurrence of TNBC, her risk for the development of new primary cancers remains substantial.

This case highlights challenges in the systemic treatment, genetic testing, and follow-up of patients with operable TNBC and other solid cancers who have a history of acute leukemia.