Jean-Michel Hannoun-Levi1, Jocelyn Gal2, Erik Van Limbergen3, Marie-Eve Chand4, Renaud Schiappa2, Viktor Smanyko5, Daniela Kauer-Domer6, David Pasquier7, Claire Lemanski8, Séverine Racadot9, Gilles Houvenaeghel10, Benjamin Guix11, Aurélie Belliere-Calandry12, Kristina Loessl13, Bulent Polat14, Cristina Gutierrez15, Razvan Galalae16, Csaba Polgar17, Vratislav Strnad18. 1. Department of Radiation Oncology, Antoine Lacassagne Cancer Centre, University of Côte d'Azur, Nice, France. Electronic address: jean-michel.hannoun-levi@nice.unicancer.fr. 2. Department of Epidemiology and Biostatistics, Antoine Lacassagne Cancer Centre, University of Cote d'Azur, Nice, France. 3. Department of Radiation Oncology, Radiation Oncology, University Hospital Gasthuisberg, Leuven, Belgium. 4. Department of Radiation Oncology, Antoine Lacassagne Cancer Centre, University of Côte d'Azur, Nice, France. 5. Centre of Radiotherapy, National Institute of Oncology, Budapest, Hungary. 6. Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria. 7. Department of Radiation Oncology, Oscar Lambret Cancer Centre, Lille University, Lille, France. 8. Department of Radiation Oncology, Montpellier Cancer Institute, Montpellier, France. 9. Department of Radiation Oncology, Leon Berard Cancer Centre, Lyon, France. 10. Department of Surgical Oncology, Paoli-Calmettes Cancer Institute, Marseille, France. 11. Department of Radiation Oncology, Medical Institute for Radiotherapy & Oncology, Barcelona, Spain. 12. Department of Radiation Oncology, Auvergne Jean Perrin Cancer Centre, Clermont-Ferrand, France. 13. Department of Radiation Oncology, Radiation Oncology, Inselspital, Bern University Hospital, Switzerland. 14. Department of Radiation Oncology, Wurzburg University, Wurzburg, Germany. 15. Department of Radiation Oncology, Catalan Institute of Oncology, Barcelona, Spain. 16. MedAustron Centre for Ion Therapy and Research, Wiener Neustadt, Austria. 17. Centre of Radiotherapy, National Institute of Oncology, Budapest, Hungary; Department of Oncology, Semmelweis University, Budapest, Hungary. 18. Department of Radiation Oncology, Erlangen University Hospital, Erlangen, Germany.
Abstract
PURPOSE: Second conservative treatment has emerged as an option for patients with a second ipsilateral breast tumor event after conserving surgery and breast irradiation. We aimed to address the lack of evidence regarding second breast event treatment by comparing oncologic outcomes after conservative treatment or mastectomy. METHODS AND MATERIALS: Oncologic outcomes were analyzed using a propensity score-matched cohort analysis study on patients who received a diagnosis of a second breast event between January 1995 and June 2017. Patient data were collected from 15 hospitals/cancer centers in 7 European countries. Patients were offered mastectomy or lumpectomy plus brachytherapy. Propensity scores were calculated with logistic regression and multiple imputations. Matching (1:1) was achieved using the nearest neighbor method, including 10 clinical/pathologic data related to the second breast event. The primary endpoint was 5-year overall survival from the salvage surgery date. Secondary endpoints were 5-year cumulative incidence of third breast event, regional relapse and distant metastasis, and disease-free and specific survival. Complications and 5-year incidence of mastectomy were investigated in the conservative treatment cohort. RESULTS: Among the 1327 analyzed patients (mastectomy, 945; conservative treatment, 382), 754 were matched by propensity score (mastectomy, 377; conservative treatment, 377). The median follow-up was 75.4 months (95% confidence interval [CI], 65.4-83.3) and 73.8 months (95% CI, 67.5-80.8) for mastectomy and conservative treatment, respectively (P = .9). In the matched analyses, no differences in 5-year overall survival and cumulative incidence of third breast event were noted between mastectomy and conservative treatment (88% [95% CI, 83.0-90.8] vs 87% [95% CI, 82.1-90.2], P = .6 and 2.3% [95% CI, 0.7-3.9] vs 2.8% [95% CI, 0.8-4.7], P = .4, respectively). Similarly, no differences were observed for all secondary endpoints. Five-year cumulative incidence of mastectomy was 3.1% (95% CI, 1.0-5.1). CONCLUSIONS: To our knowledge, this is the largest matched analysis of mastectomy and conservative treatment combining lumpectomy with brachytherapy for second breast events. Compared with mastectomy, conservative treatment does not appear to be associated with any differences in terms of oncologic outcome. Consequently, conservative treatment could be considered a viable option for salvage treatment.
PURPOSE: Second conservative treatment has emerged as an option for patients with a second ipsilateral breast tumor event after conserving surgery and breast irradiation. We aimed to address the lack of evidence regarding second breast event treatment by comparing oncologic outcomes after conservative treatment or mastectomy. METHODS AND MATERIALS: Oncologic outcomes were analyzed using a propensity score-matched cohort analysis study on patients who received a diagnosis of a second breast event between January 1995 and June 2017. Patient data were collected from 15 hospitals/cancer centers in 7 European countries. Patients were offered mastectomy or lumpectomy plus brachytherapy. Propensity scores were calculated with logistic regression and multiple imputations. Matching (1:1) was achieved using the nearest neighbor method, including 10 clinical/pathologic data related to the second breast event. The primary endpoint was 5-year overall survival from the salvage surgery date. Secondary endpoints were 5-year cumulative incidence of third breast event, regional relapse and distant metastasis, and disease-free and specific survival. Complications and 5-year incidence of mastectomy were investigated in the conservative treatment cohort. RESULTS: Among the 1327 analyzed patients (mastectomy, 945; conservative treatment, 382), 754 were matched by propensity score (mastectomy, 377; conservative treatment, 377). The median follow-up was 75.4 months (95% confidence interval [CI], 65.4-83.3) and 73.8 months (95% CI, 67.5-80.8) for mastectomy and conservative treatment, respectively (P = .9). In the matched analyses, no differences in 5-year overall survival and cumulative incidence of third breast event were noted between mastectomy and conservative treatment (88% [95% CI, 83.0-90.8] vs 87% [95% CI, 82.1-90.2], P = .6 and 2.3% [95% CI, 0.7-3.9] vs 2.8% [95% CI, 0.8-4.7], P = .4, respectively). Similarly, no differences were observed for all secondary endpoints. Five-year cumulative incidence of mastectomy was 3.1% (95% CI, 1.0-5.1). CONCLUSIONS: To our knowledge, this is the largest matched analysis of mastectomy and conservative treatment combining lumpectomy with brachytherapy for second breast events. Compared with mastectomy, conservative treatment does not appear to be associated with any differences in terms of oncologic outcome. Consequently, conservative treatment could be considered a viable option for salvage treatment.