260P Adjuvant paclitaxel–cyclophosphamide in HR+/HER2− early breast cancer: A multicenter, retrospective, real-world study

Background: Anthracycline-free regimens are commonly used in selected patients (pts) with HR+/HER2-eBC.Docetaxel-cyclophosphamide is a standard option but is associated with relevant toxicity.Weekly paclitaxel shows a more favorable safety profile, and metastatic data suggest comparable efficacy to docetaxel.However, PC has not been systematically evaluated in the adjuvant setting, and real-world data is needed. Methods:We conducted a multicenter, retrospective, real-world study across two Spanish institutions including HR+/HER2-eBC pts treated with adjuvant PC between January 2020 and April 2025.Paclitaxel (80 mg/m 2 weekly) and cyclophosphamide (600 mg/m 2 q3w) were administered for 4-6 cycles.Collected data included clinicopathologic characteristics, chemotherapy exposure, treatment-emergent adverse events (TEAEs), and clinical outcome.Results: Fifty-two pts were included.Median age was 56.6 years (range 34-79), 55.8% were postmenopausal, and 63.5% had no lymph node involvement.Four cycles of PC were indicated for most pts (92.3%).Genomic testing was performed in 46 pts (88.5%), predominantly using Oncotype DX (95.7%), with higher use across nodal negative pts compared to nodes positive ones (93.9% pN0 pts vs. 79.0%pN+ pts).Among tested pts, 60.9% had a high-risk genomic profile, more frequently in the node-negative than in the node-positive subgroup (66.7% vs. 31.6%).Overall, 98.1% pts completed the planned treatment schedule.The most frequent hematologic TEAE was neutropenia (53.9%; grade 3: 21.2%), while febrile neutropenia was uncommon (1.9%).Peripheral neuropathy was the most common non-hematologic TEAE (61.5%), with no grade 3 events.No treatment-related deaths were reported, and hospitalization was rare (1.9%).After a median follow-up of 31.1 months (range 5-67), all pts were alive, and invasive disease events were infrequent (3.8%, two pts), including one regional and one metastatic recurrence. Conclusions:Adjuvant PC showed a manageable safety profile and encouraging effectiveness in HR+/HER2-eBC pts.Longer follow-up and larger studies are needed to confirm these findings.