Method to Suppress Side Effects of Neoadjuvant Chemotherapy in HER2-Positive Breast Cancer Identified

Gangnam Severance Anseonggui and Kim Jihyung Professor Team
TCHP Regimen with Reduced Carboplatin Dose
Same Treatment Effect, Confirmed Reduction in Side Effects Such as Anemia

Professor An Seong-gwi, Department of Breast Surgery, Gangnam Severance Hospital (left), Professor Kim Ji-hyung, Department of Oncology.

[Asia Economy Reporter Lee Gwan-joo] A TCHP neoadjuvant chemotherapy regimen that maintains treatment efficacy while reducing side effects has been proposed for patients with rapidly metastatic HER2-positive breast cancer.

Professors Ahn Sung-gwi from the Department of Breast Surgery and Kim Ji-hyung from the Department of Oncology at Yonsei University Gangnam Severance Hospital, along with Professor Ji Jung-hwan from the Department of Breast Surgery at International St. Mary's Hospital, announced on the 6th the results of their study titled "Pathologic Complete Response According to Carboplatin Dose in HER2-Positive Breast Cancer Patients Treated with TCHP Neoadjuvant Therapy."

HER2-positive breast cancer is highly aggressive and rapidly metastatic, so neoadjuvant chemotherapy is used before surgery to enhance treatment efficacy. The TCHP regimen, which combines targeted therapy agents (Herceptin, Perjeta) and cytotoxic chemotherapy agents (Carboplatin, Docetaxel), has shown high treatment efficacy and is used as a standard therapy.

Despite the high complete response rate of the TCHP regimen, side effects related to cytotoxic chemotherapy agents occur. The administration of high-dose carboplatin increases the incidence of hematologic side effects such as anemia and thrombocytopenia. These side effects may require blood transfusions and can delay surgical treatment, making it difficult to administer TCHP therapy to elderly patients and those with vulnerabilities.

The research team collected data from 294 patients diagnosed with HER2-positive breast cancer who received TCHP neoadjuvant chemotherapy between April 2015 and December 2020. They divided the patients into two groups based on carboplatin dose: standard dose AUC6 (up to 900 mg) and low dose AUC5 (up to 750 mg), and analyzed the pathologic complete response rate as well as the frequency of grade 3 or higher anemia and blood transfusions. Among the patients, 234 (80%) received the standard dose, and 60 (20%) received the low dose.

Regarding the complete response rate, which indicates the complete disappearance of cancer, the standard dose group showed 70.9%, while the low dose group showed 80.0%. In a matched group adjusted for other clinical factors, the response rates were 76.8% and 78.6%, respectively, showing no difference in treatment outcomes according to carboplatin dose.

When comparing side effects according to carboplatin dose, grade 3 or higher anemia occurred in 34% of the standard dose group and 18% of the low dose group, showing a significant difference. Actual blood transfusions were performed in 22% and 10% of patients, respectively, nearly double in the standard dose group. However, since this study was retrospective and limited to hematologic changes according to carboplatin dose, further research is needed.

Professor Ahn said, "Reducing the carboplatin dose may lower treatment outcomes, but we confirmed that appropriate dose adjustment can reduce side effects while maintaining the same treatment efficacy," adding, "Since chemotherapy side effects affect patients' quality of life as much as treatment prognosis, a diverse and careful approach to chemotherapy use is necessary."

This paper was published in the international academic journal Cancer Medicine.