Chemotherapy versus tamoxifen versus chemotherapy plus tamoxifen in node-positive, estrogen receptor-positive breast cancer patients. Very late results of the gruppo di ricerca per la chemio-ormonoterapia adiuvante (GROCTA) 01-Trial in early breast cancer
Breast Cancer Research and Treatment, 03/09/2011
Boccardo F et al – The authors demonstrated that T is an effective alternative to CT for node-positive, ER-positive, breast cancer patients, regardless of their actual menopausal status, and that the additional benefit, especially on late survival, provided by the addition of CT to this anti-estrogen, was minimal.
Methods- 504 node-positive, ER-positive, women randomly assigned to 10 CT courses or to 5 years of T or to combination of 2 (CTT)
- DFS and OS primary trial-endpoints
- DFS data updated in 75% of patients and S data in 95% of them
- Cox regression models used to check for prognostic features to estimate HR for treatment comparisons and to test for possible interaction between variables and treatment effects
- Interactions between treatments and ER or PgR median levels studied with sub-population treatment effect pattern plot (STEPP) methodology
- After median follow-up time of 21 years, DFS and OS benefits, previously favouring T over CT, continued to be observed, even though they were more evident in the first 6–7 years
- CTT advantages of DFS and OS over T alone confirmed
- Additional benefit limited to first 10–12 years as S curves crossed over afterwards
- After STEPP analysis, neither ER nor PgR concentrations fully discriminated patients who could benefit from T alone
