Pattern and risk factors of isolated local relapse among women with hormone receptor-positive and HER2-negative breast cancer and lymph node involvement: 10-year follow-up analysis of the PACS 01 and PACS 04 trials

PurposeWe aimed to determine the pattern of isolated local recurrences (ILR) in women with stage II-III hormone receptor-positive and human epidermal growth factor receptor 2 breast cancer (HR + /HER2-BC) after 10-year follow-up.MethodsUNICANCER-PACS 01 and PACS 04 trials included 5,008 women with T1-T3 and N1-N3 to evaluate the efficacy of different anthracycline +/- taxanes-containing regimens after modified mastectomy or lumpectomy plus axillary lymph node dissection. We analyzed the data from 2,932 women with HR + /HER2- BC to evaluate the cumulative incidence of ILR and describe the factors associated with ILR.ResultsAfter a median follow-up of 9.1 years (95% CI 9.0-9.2 years), the cumulative incidence of ILR increased steadily between 1 and 10 years from 0.2% to 2.5%. The multivariable analysis showed that older age (subhazard ratios [sHR] = 0.95, 95% CI 0.92-0.99) and mastectomy (sHR = 0.39, 95% CI 0.17-0.86) were associated with lower risk of ILR, and no adjuvant endocrine therapy (sHR = 2.73, 95% CI 1.32 7-5.67) with increased risk of ILR.ConclusionIn this population of high-risk patients with localized HR + /HER2- BC, the risk of ILR was low but remained constant over 10 years. Younger age at diagnosis, breast-conserving surgery, and adjuvant endocrine therapy were independent risk factors of ILR.

Automated summary

The aim of this study was to determine the pattern of isolated local recurrences in women with hormone receptor-positive and human epidermal growth factor receptor 2 breast cancer. The results showed that the cumulative incidence of isolated local recurrences increased steadily over a 10-year follow-up period and factors such as younger age, breast-conserving surgery, and adjuvant endocrine therapy were identified as independent risk factors.