{
  "abstract": "Background and Importance Dose-dense (DD) chemotherapy has been incorporated into breast cancer management with the objective of enhancing therapeutic efficacy by reducing administration intervals to two weeks, without increasing cumulative dose or toxicity.Aim and Objectives This study evaluates the safety profile of the epirubicin-cyclophosphamide (EC) followed by paclitaxel (P), both given in DD regimens, used as neoadjuvant or adjuvant therapy.Material and Methods A retrospective observational study was conducted in a tertiary hospital including patients treated between January 2024 and September 2025. Collected data included demographic characteristics, disease stage, treatment type, number of cycles administered, treatment completion, delays or dose reductions, and adverse events (AEs). Data sources were the electronic health record Diraya and the prescription system Farmis_Oncofarm .Results Thirty-seven patients were included, with a median age of 51 years; two were male. Disease stages included 49% stage III, 41% stage II, and 10% stage I. Regarding molecular subtype, 65% were Luminal B, 27% Luminal A, and 5% Triple Negative. Adjuvant chemotherapy was administered in 62% of cases, while 38% received neoadjuvant therapy.During EC administration, the most frequent AEs were asthenia (81%), nausea (54%) and mucositis (35%). Eight patients required cycle spacing: five due to recovery from previous infections and two due to myelotoxicity. Epirubicin dose was reduced in seven patients, primarily due to asthenia or nausea. One patient discontinued treatment after ischaemia secondary to chemotherapy-induced vasospasm.During P administration, neurotoxicity was the predominant AE(68%), followed by asthenia (57%) and nausea (24%). Five patients required cycle delays: four due to myelotoxicity and one following an anaphylactic reaction. Paclitaxel dosage was adjusted in sixteen cases, mostly for neurotoxicity. Four patients continued with weekly P due to intolerance and eleven patients did not complete paclitaxel: four due to severe infusional reaction, two due to myelotoxicity, two owing to neurotoxicity and three still on treatment at data cutoff.Conclusion and Relevance In conclusion, gastrointestinal toxicity and asthenia were more frequent during EC, whereas neurotoxicity predominated with P. Myelotoxicity was the main cause of cycle delays despite prophylactic administration of colony-stimulating factors. Although the absence of a comparator and limited sample size restrict generalisability, the findings support that DD chemotherapy presents an acceptable and manageable safety profile in breast cancer.Conflict of Interest No conflict of interest",
  "authors": [
    {
      "affiliations": [
        "Juan Ramon Jimenez University Hospital, Hospital Pharmacy, Huelva, Spain"
      ],
      "name": "E Paradela García"
    },
    {
      "affiliations": [
        "Juan Ramon Jimenez University Hospital, Hospital Pharmacy, Huelva, Spain"
      ],
      "name": "A Ponce González"
    },
    {
      "affiliations": [
        "Juan Ramon Jimenez University Hospital, Hospital Pharmacy, Huelva, Spain"
      ],
      "name": "I Corriente Gordon"
    },
    {
      "affiliations": [
        "Juan Ramon Jimenez University Hospital, Hospital Pharmacy, Huelva, Spain"
      ],
      "name": "S Camacho Parreño"
    }
  ],
  "title": "5PSQ-070 Safety analysis of dose-dense chemotherapy in breast cancer treatment",
  "uid": "4d9d8dc5-3cac-5cf4-bec2-cae29b9ad082"
}