A team of researchers at Gangnam Severance Hospital said they discovered a pathological complete response (pCR) when administering HER2 positive breast cancer patients with a dose of carboplatin together with neoadjuvant TCHP (Taxotere +Carboplatin+Herceptin+Perjeta).

HER2 benign breast cancer exhibits fast metastasis and high aggression, and preoperative chemotherapy is used to increase the therapeutic effect. TCHP therapy, which uses both targeted therapy (herceptin, perzeta) and cytotoxic anticancer drugs (carboplatin, docetaxel), has demonstrated high therapeutic effects when implemented as a standard therapy.

However, TCHP therapy is accompanied by side effects from cytotoxic anticancer drugs although it leads to high remission rates. High doses of carboplatin injections often cause hematological side effects such as anemia and platelet reduction. According to the researchers, these side effects require blood transfusions and can lead to delayed surgical treatment, making it difficult to implement this therapy in elderly and vulnerable patients.

The research team led by Professors Ahn Sung-gwee and Kim Jee-hung collected data from 294 patients who received TCHP preoperative chemotherapy treatment among patients diagnosed with HER2 positive breast cancer. The pCR rate, occurrence of grade 3/4 anemia, and transfusion rate were analyzed in groups that received carboplatin standard dose AUC6 (up to 900mg) and low dose AUC5 (up to 750mg).

The AUC6 group demonstrated a 70.9 percent pCR rate while the AUC5 group was 80 percent in this regard. In the matching group that corrected other clinical factors, no significant difference in the pcR rates with carboplatin dose were observed. Additionally, anemia grade 3/4 was 34 percent in the AUC6 group and 18 percent in AUC5, while the actual transfusion was nearly twice as different at 22 percent and 10 percent, respectively.

However, the researchers admitted that further research was required as it was a retrospective research design limited to hematological changes according to carboplatin dose.

"Lowering the dose of carboplatin usually reduces treatment outcomes, but we have confirmed that with proper dose adjustment, side effects can be reduced and the same therapeutic effect can be seen," said Professor Ahn Sung-gwee. "As anti-cancer side effects affect the patient's quality of life, a diverse and cautious approach to the use of anti-cancer drugs is needed."

The paper was published in the international journal Cancer Medicine.