by RESPECT study
group
The Breast: VOLUME 66, P245-254, DECEMBER
01, 2022
Purpose
To gauge the effects of treatment practices on prognosis for
older patients with HER2-positive early breast cancer, particularly to
determine whether adjuvant trastuzumab alone can offer benefit over no adjuvant
therapy. This is a prospective cohort study which accompanies the RESPECT that
is a randomized-controlled trial (RCT).
Methods
Patients who declined the RCT were treated based on the
physician's discretion. We studied the 1) trastuzumab-plus-chemotherapy group,
2) trastuzumab-monotherapy group, and 3) non-trastuzumab group (no therapy or
anticancer therapy without trastuzumab). The primary endpoint was disease-free
survival (DFS), which was compared using the propensity-score method.
Relapse-free survival (RFS) and health-related quality of life (HRQoL) were
assessed.
Results
We enrolled 123 patients aged over 70 years (median: 74.5).
Treatment categories were: trastuzumab-plus-chemotherapy group
(n = 36, 30%), trastuzumab-monotherapy group (n = 52, 43%),
and non-trastuzumab group (n = 32, 27%). The 3-year DFS was 96.7% in
trastuzumab-plus-chemotherapy group, 89.2% in trastuzumab-monotherapy group,
and 82.5% in non-trastuzumab group. DFS in non-trastuzumab group was lower than
in trastuzumab-plus-chemotherapy and trastuzumab-monotherapy groups (propensity-adjusted
hazard ratio; HR: 3.29; 95% CI: 1.15–9.39; P = 0.026). The RFS in
non-trastuzumab group was lower than in trastuzumab-plus-chemotherapy and
trastuzumab-monotherapy groups (propensity-adjusted HR = 7.80; 95%
CI: 2.32–26.2, P < 0.0001). There were no significant intergroup
differences in the proportions of patients showing HRQoL deterioration at 36
months (P = 0.717).
Conclusion
Trastuzumab-treated patients had better prognoses than
patients not treated with trastuzumab without deterioration of HRQoL.
Trastuzumab monotherapy could be considered for older patients who reject
chemotherapy.
