Luteolin br DFS and OS rates br The patient survival
DFS and OS rates
The patient survival rates were evaluated during a median follow-up Luteolin of 56 mo (range: 6-180 mo). There was no significant difference in OS and DFS between the CHT/ET and ET-alone groups (P ¼ 0.416 and 0.210, respectively, Fig. 3). Given that the CHT/ET group had more risk factors associ-ated with BC, there were no significant differences in OS and DFS rates between groups, and that the DFS rate in the CHT/ET group was slightly better than that in the ET-alone group, we speculated that a subgroup of patients might benefit from CHT.
To determine what subgroup of patients benefited from CHT in this study, the effect of CHT was assessed in subgroup analysis. The DFS rates are summarized in Figure 4. Among the 12 variables assessed, four subgroups had prognostic sig-nificance between the CHT/ET and ET-alone groups, including HER2 overexpression (P ¼ 0.042), grade 3 histological classification (P ¼ 0.030), stage T1c (P ¼ 0.038), and PR 20% (P ¼ 0.033). The KaplaneMeier curves also confirmed that these four subgroups of patients could benefit from CHT (Fig. 5A-D). None of these subgroups had prognostic signifi-cance for OS between the CHT/ET and ET-alone groups (Supplementary Fig. 1).
Risk model for CHT guidance
Although the four patient subgroups can achieve a DFS benefit from modern CHT, a significant proportion of patients have two or more risk factors. It is possible that increasing numbers of risk factors may result in additional benefits from CHT. If the benefits in these four subgroups are due to the proportion of patients who simultaneously display multiple risk factors, patients with fewer risk factors may have no apparent benefit from CHT and can be exempted from CHT. Therefore, only patients with a sufficient number of risk factors require CHT. To confirm this theory, we divided the patients in this study into five groups according to their number of risk factors.
As there were too few patients with three or four risk fac-tors; these groups were merged into a single group. Among
Table e Demographic characteristics of all patients and univariate analysis of tumor-related and treatment factors in the CHT/ET and ET alone groups.
HER2 ¼ human epidermal growth factor receptor 2; NA ¼ not available; BCS ¼ breast conserving surgery; OFS ¼ ovarian function suppression (including ovariectomy and goserelin). * PR negative was defined as 20%, while > 20% was considered positive.
respectively). Similar to the observations for the DFS rate, there were no significant differences in OS among patients with 1 risk factor between the CHT/ET and ET-alone groups (no patients died in the 0 risk factor group). There was also no difference between groups among patients with more than 3 risk factors; however, the OS rate was higher in patients with 2
Fig. 2 e The proportions of included patients administered adjuvant systemic treatments. (A) CHT regimens in patients with luminal A subtype disease. (B) CHT regimens in patients with luminal B subtype disease. (C) ET period for all included patients. (D) ET regimens for all patients. (Color version of figure is available online.)
risk factors in the CHT/ET group than in the ET-alone group (Supplementary Fig. 2A-C).
Our study assessed IHC and clinicopathological features to evaluate whether patients with early-stage HR-positive BC with negative lymph node involvement could benefit from CHT. Although the tumors in the CHT/ET group had more aggressive biological behaviors compared with those of the ET-alone group, there were no significant differences in DFS and OS between the two groups, and the DFS rate in the CHT/ET group was slightly better than that in the ET-alone group. Therefore, CHT improved the DFS of some patients. Subgroup analysis to identify these benefitting patients revealed that PR 20%, HER2 overexpression, stage T1c, and histologic grade 3 BC may benefit from CHT. To determine whether these four risk factors were
independent, we divided the patients into five groups ac-cording to the numbers of risk factors and found no sig-nificant differences in DFS rates in those with 0 or 1 of these four risk factors. However, patients with at least two risk factors may benefit from CHT. Therefore, these four parameters combined may predict the benefit of CHT. In other words, young patients with HR-positive and stage pT1N0 BC may be exempt from CHT (i.e., ET alone is enough) if they have up to one of the four risk factors (PR 20%, HER2 overexpression, stage T1c, or histological grade 3) because CHT does not improve their OS or DFS; otherwise, CHT should be required.