The benefit of adjuvant radiotherapy after breast conserving surgery in older patients with low risk breast cancer- a meta-analysis of randomized trials.
OBJECTIVE
It is currently unclear whether patients with low risk breast cancer receiving adjuvant endocrine therapy need adjuvant radiation therapy after breast conserving surgery. The data of randomized trials are available.


METHODS
In a database search 5 randomized trials including in total 3766 mostly elderly patients with early stage breast cancer tr﻿eated either with adjuvant endocrine therapy or with endocrine therapy and additional whole breast radiation after breast conserving surgery were identified. Published hazard ratios for time to local recurrence were the basis of our meta-analysis. Meta-analysis of the effect sizes on local recurrence was performed using a random effects model based on parameter estimates of log hazard ratios in Cox models and their standard errors. Furthermore, overall survival was examined.


RESULTS
Adjuvant hormone therapy alone in mostly older patients with low risk breast cancer resulted in significantly shorter time to local relapse compared to radiation therapy combined with hormone therapy (Hazard Ratio: 6.8, 95% CI: 4.23-10.93, p < 0.0001) . There was no significant difference for overall survival.


CONCLUSIONS
Additional radiation therapy to hormone therapy did improve local relapse in breast cancer patients but did not show significant impact on overall survival.
Department of Radiation Oncology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
Christiane
C
Matuschek
Department of Radiation Oncology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany. boelke@med.uni-duesseldorf.de.|Klinik für Strahlentherapie und Radiologische Onkologie, Heinrich Heine Universität, Moorenstr. 5, D-40225, Düsseldorf, Germany. boelke@med.uni-duesseldorf.de.
Edwin
E
Bölke
Department of Radiation Oncology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
Jan
J
Haussmann
Department of Gynecologic and Obtresic, Heinrich Heine University, Dusseldorf, Germany.
Svjetlana
S
Mohrmann
Department of Senology, Sana Krankenhaus Dusseldorf, Dusseldorf, Germany.
Carolin
C
Nestle-Krämling
Department of Dermatology, Medical Faculty Heinrich Heine University, Dusseldorf, Germany.
Peter Arne
PA
Gerber
Department of Radiation Oncology, LMU Munich, Munich, Germany.
Stefanie
S
Corradini
Department of General, Visceral and Thoracic Surgery, Harzkliniken Goslar, Goslar, Germany.
Klaus
K
Orth
Division of Biostatistics and Bioinformatics, Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Kai
K
Kammers
Department of Radiation Oncology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany.
Wilfried
W
Budach
D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000401:mortality / Q000532:radiotherapy* / Q000601:surgery; D059248:Chemoradiotherapy / Q000379:methods; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D015412:Mastectomy, Segmental; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D013629:Tamoxifen / Q000627:therapeutic use
D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen
Adjuvant therapy; Low risk breast cancer; Radiation therapy; Tamoxifen