Triple-negative breast cancer is the subtype oncologists most want better answers for: it lacks the hormone and HER2 targets that anchor other regimens, and recurrence in early-stage disease is common. Whether to add carboplatin, a platinum agent that damages cancer cell DNA, to standard chemotherapy has been debated for years on limited evidence. A randomised, multicentre phase 3 trial led by Professors Sohn Joo-hyuk and Kim Geon-min of Yonsei Cancer Center, with investigators at 22 Korean institutions, now provides a confirmatory answer.
The KCSG BR 15-1 trial, also known as PEARLY, enrolled 868 patients with stage 2 to 3 triple-negative breast cancer without distant metastasis between 2016 and 2020, split evenly between conventional anthracycline, cyclophosphamide and taxane chemotherapy and the same regimen plus carboplatin. After a median follow-up of about 57 months, event-free survival was 82.3 percent in the carboplatin arm against 75.1 percent with standard treatment, an absolute gain of 7.2 percentage points.
Published in Annals of Oncology and reported by Yonsei's health system in August 2026, the result strengthens the evidence base beneath carboplatin-containing regimens, which already feature alongside pembrolizumab in current standards of care. Sohn described it as the first confirmatory phase 3 trial conducted entirely in Korea to establish carboplatin's benefit in this population, and the findings have been incorporated into American clinical practice guidelines, a notable mark of international reach for a domestically run trial.