title: Prognostic role of adjuvant radiotherapy in triple-negative breast cancer: A historical cohort study.
abstract: The value of adjuvant radiotherapy in triple-negative breast cancer (TNBC) is currently debated. We assessed the association between adjuvant radiotherapy and survival in a large cohort of Asian women with TNBC. Women diagnosed with TNBC from 2006 to 2011 in five Asian centers (N = 1,138) were included. Survival between patients receiving mastectomy only, breast-conserving therapy (BCT, lumpectomy and adjuvant radiotherapy) and mastectomy with radiotherapy were compared, and adjusted for demography, tumor characteristics and chemotherapy types. Median age at diagnosis was 53 years (range: 23-96 years). Median tumor size at diagnosis was 2.5 cm and most patients had lymph node-negative disease. The majority of patients received adjuvant chemotherapy (n = 861, 76%) comprising predominantly anthracycline-based regimes. In 775 women with T1-2, N0-1, M0 TNBCs, 5-year relative survival ratio (RSR) was highest in patients undergoing mastectomy only (94.7%, 95% CI: 88.8-98.8%), followed by BCT (90.8%, 95% CI: 85.0-94.7%), and mastectomy with radiotherapy (82.3%, 95% CI: 73.4-88.1%). The adjusted risks of mortality between the three groups were not significantly different. In 363 patients with T3-4, N2-3, M0 TNBCs, BCT was associated with highest 5-year RSR (94.1%, 95% CI: 81.3-99.4%), followed by mastectomy with radiotherapy (62.7%, 95% CI: 54.3-70.1%), and mastectomy only (58.6%, 95% CI: 43.5-71.6%). Following multivariable adjustment, BCT and mastectomy with radiotherapy remained significantly associated with lower mortality risk compared to mastectomy only. Overall, adjuvant radiotherapy was associated with higher survival in women aged <40 years, but not in older women. Adjuvant radiotherapy appears to be independently associated with a survival gain in locally advanced as well as in very young TNBC.
authors.affiliation: Faculty of Medicine, Julius Centre University of Malaya, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia.|Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands.|National Clinical Research Centre, Kuala Lumpur Hospital, Jalan Pahang, Kuala Lumpur, Malaysia.
authors.forename: Nirmala
authors.initials: N
authors.lastname: Bhoo-Pathy
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.|Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Helena M
authors.initials: HM
authors.lastname: Verkooijen
authors.affiliation: Department of Radiation Oncology, National Cancer Centre Singapore, Singapore, Singapore.
authors.forename: Fuh-Yong
authors.initials: FY
authors.lastname: Wong
authors.affiliation: Department of Radiation Oncology, Erasmus MC Cancer Institute, Rotterdam, The Netherlands.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Pignol
authors.affiliation: Breast Surgery Division, Department of Surgery, The University of Hong Kong, Pokfulam, Hong Kong.
authors.forename: Ava
authors.initials: A
authors.lastname: Kwong
authors.affiliation: Department of General Surgery, Tan Tock Seng Hospital, Singapore, Singapore.
authors.forename: Ern-Yu
authors.initials: EY
authors.lastname: Tan
authors.affiliation: Department of Surgery, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia.
authors.forename: Nur
authors.initials: N
authors.lastname: Aishah Taib
authors.affiliation: Department of Radiation Oncology, National Cancer Centre Singapore, Singapore, Singapore.
authors.forename: Wen-Long
authors.initials: WL
authors.lastname: Nei
authors.affiliation: Clinical Oncology Unit, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia.
authors.forename: Gwo-Fuang
authors.initials: GF
authors.lastname: Ho
authors.affiliation: Department of General Surgery, Singapore General Hospital, Singapore, Singapore.
authors.forename: Benita
authors.initials: B
authors.lastname: Tan
authors.affiliation: Department of Surgery, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia.
authors.forename: Patrick
authors.initials: P
authors.lastname: Chan
authors.affiliation: Department of Hematology Oncology, National University Cancer Institute, National University Health System, Singapore, Singapore.
authors.forename: Soo-Chin
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore.|Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore and National University Health System, Singapore, Singapore.
authors.forename: Mikael
authors.initials: M
authors.lastname: Hartman
authors.affiliation: Clinical Oncology Unit, Faculty of Medicine, University of Malaya, Lembah Pantai, Kuala Lumpur, Malaysia.
authors.forename: Cheng-Har
authors.initials: CH
authors.lastname: Yip
authors.affiliation: Department of Medical Oncology, National Cancer Centre Singapore, Singapore, Singapore.|Department of Clinical Sciences, Duke-NUS Graduate Medical School Singapore, Singapore, Singapore.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Dent
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008408:Mastectomy / Q000379:methods; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D016019:Survival Analysis; D016896:Treatment Outcome; D064726:Triple Negative Breast Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000532:radiotherapy* / Q000601:surgery; D055815:Young Adult
chemical_list: D000970:Antineoplastic Agents
keywords: Asia; adjuvant radiotherapy; postmastectomy; survival; triple-negative breast cancer