146P Long-term outcomes of patients with triple-negative breast cancer treated with adjuvant dose-dense sequential chemotherapy (ddsc): A Hellenic Cooperative Oncology Group (HeCOG) study

Our aim was to evaluate long-term clinical outcomes in patients with triple-negative breast cancer (TNBC) treated with adjuvant dose-dense sequential chemotherapy (ddsc). Data from patients with TNBC treated with adjuvant ddsc in the context of 3 phase III and 4 observational studies were retrieved from the HeCOG electronic database. All 7 studies included node-positive or "intermediate" high-risk node-negative patients. To examine the risk factors associated with disease-free survival (DFS) and overall survival (OS), Cox regression was applied. A random forest approach was employed by two distinct machine learning models to predict DFS and OS. Using these models, the clinical importance of input variables was determined. In total, 831 patients with early-stage TNBC were included, median age 52 years. With a median follow-up of 10.7 years, disease progression was reported in 179 (21.7%) patients, while 201 (24.2%) patients died. Thirty seven (4.5%) patients developed a second malignancy. 5-year (yr) and 10-yr DFS was 78% and 74%, while 5-yr and 10-yr OS was 84% and 76%, respectively. The majority of progression events (141, 78.8%) occurred within the first 3 years, while disease progression was reported in 17 (2.1%) patients after 5 years from diagnosis. The random survival forest identified the number of infiltrated lymph nodes as the most important risk factor for both DFS and OS, followed by the size of the primary tumor, age at diagnosis, CD8 T cells, menopausal status at diagnosis, neuropathy, tumor-infiltrating lymphocytes and radiation therapy. Most frequent adverse events were nausea (41.6%), fatigue (32.7%), neuropathy sensory (27.7%), arthralgia (19.2%), myalgia (17.2%), vomiting (16.9%), constipation (12.8%), diarrhea (9.9%), mucositis (9.7%), hand-foot syndrome (6.7%) and allergic reactions (5.8%). In this study, we assessed 10-yr outcomes in patients with early-stage TNBC treated with ddsc within seven clinical trials. Clinical and pathological factors need to be combined to accurately predict which patients with recur after treatment.