Adjuvant therapy after excision and radiation of isolated postmastectomy locoregional breast cancer recurrence: definitive results of a phase III randomized trial (SAKK 23/82) comparing tamoxifen with observation.
BACKGROUND
Adjuvant systemic treatment for patients with isolated locoregional recurrence (ILRR) of breast cancer is based on a single reported randomized trial. The trial, conducted by the Swiss Group for Clinical Cancer Research, compared tamoxifen (TAM) with observation after complete excision of the ILRR and proper radiotherapy. We performed a definitive analysis of treatment outcome at >11 years of follow-up, after the majority of the patients had a subsequent event of interest. Patient and methods One hundred and sixty-seven patients with 'good-risk' characteristics of disease were randomized. 'Good-risk' was defined as estrogen receptor expression in the ILRR, or having a disease-free interval of >12 months and a recurrence consisting of three or less tumor nodules, each </=3 cm in diameter. Seventy-nine percent of the patients were postmenopausal at randomization.


RESULTS
The median follow-up time of the surviving patients was 11.6 years. The median post ILRR disease-free survival (DFS) was 6.5 years with TAM and 2.7 years with observation (P = 0.053). The difference was mainly due to reduction of further local relapses (P = 0.011). In postmenopausal patients, TAM led to an increase of DFS from 33% to 61% (P = 0.006). In premenopausal women, 5-year DFS was 60%, independent of TAM medication. For the whole study population, the median post-recurrence overall survival (OS) was 11.2 and 11.5 years in the observation and the TAM group, respectively; premenopausal patients experienced a 5-year OS of 90% for observation compared with 67% for TAM (P = 0.175), while the respective figures for postmenopausal patients were both 75%.


CONCLUSIONS
These definitive results confirmed that TAM significantly improves the post-recurrence DFS of patients after local treatment for ILRR. This beneficial effect does not translate into a detectable OS advantage.
Waeber
M
M
Institute of Medical Oncology, Inselspital, University of Bern, Bern, Switzerland.
Castiglione-Gertsch
M
M
Dietrich
D
D
Thürlimann
B
B
Goldhirsch
A
A
Brunner
K W
KW
Borner
M M
MM
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy / Q000601:surgery; D002278:Carcinoma in Situ / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D003131:Combined Modality Therapy; D018572:Disease-Free Survival; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental / Q000379:methods; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality* / Q000473:pathology / Q000628:therapy*; D009367:Neoplasm Staging; D019370:Observation / Q000379:methods*; D011336:Probability; D016016:Proportional Hazards Models; D018714:Radiotherapy, Adjuvant; D018570:Risk Assessment; D015996:Survival Rate; D013629:Tamoxifen / Q000008:administration & dosage*; D016896:Treatment Outcome
D013629:Tamoxifen