Background: Few studies have been performed on post-relapse survival in patients with the early and late distant recurrence in estrogen receptor (ER)-positive, HER2-negative breast cancer.
Methods: A total of 205 patients with the early distant recurrence and 134 patients with the late distant recurrence of ER-positive, HER2-negative breast cancer who had undergone breast surgery or neoadjuvant chemotherapy between January 2000 and December 2004 were registered from nine institutions. Prognostic factors for post-relapse survival in patients with the early and late recurrence were analyzed.
Results: Post-relapse survival was significantly longer in patients with the late recurrence than in patients with the early recurrence. Predictive factors for post-relapse survival in patients with the early recurrence were lack of adjuvant chemotherapy, a long disease-free interval, and long durations of endocrine therapies and chemotherapies after relapse. In patients with the late recurrence, post-relapse survival was significantly improved for those individuals with one metastatic organ at relapse and individuals who were treated with the first-line and subsequent endocrine therapies for prolonged periods. Moreover, ER expression in primary breast tumors of late recurrence patients was significantly higher with a duration of the first-line endocrine therapy >6 months than in those with a duration ≤6 months.
Conclusion: Predictors for prognosis after relapse differed between patients with the early and late distant recurrence. Endocrine responsiveness after relapse is a key factor for improved post-relapse survival, and it is thus important to establish whether metastatic tumors are endocrine-resistant in ER-positive, HER2-negative recurrent breast cancer.
Keywords: Breast cancer; Endocrine therapy; Estrogen receptor-positive; Post-relapse survival; Prognosis.