TY - JOUR
T1 - Incidence of second primary malignancy after breast cancer and related risk factors—Is breast-conserving surgery safe? A nested case–control study
AU - Li, Zhuyue
AU - Wang, Kang
AU - Shi, Yang
AU - Zhang, Xuemei
AU - Wen, Jin
N1 - Funding Information:
Key words: second primary malignancy, breast cancer, risk factor, radiotherapy, breast-conserving surgery Abbreviations: BC: breast cancer; ER: estrogen receptor; HR: Hazard ratio; PR: progesterone receptor; SIR: standardized incidence ratio; SPM: second primary malignancy Additional Supporting Information may be found in the online version of this article. *Z.L. and K.W. share co-first authorship. Conflict of Interest: All authors have no conflict of interest to declare. Grant sponsor: Science & Technology Department of Sichuan Province, China; Grant numbers: 2018KZ0046, 2017FZ0104; Grant sponsor: The National Natural Science Foundation of China; Grant number: 71874115 DOI: 10.1002/ijc.32259 History: Received 24 Sep 2018; Accepted 25 Feb 2019; Online 12 Mar 2019. Correspondence to: Jin Wen, PhD, Institute of Hospital Management, West China Hospital, Guo Xue Xiang 37, Chengdu 610041, China. Tel.: +86-18980606225, E-mail: huaxiwenjin@163.com
Publisher Copyright:
© 2019 UICC
PY - 2020/1/15
Y1 - 2020/1/15
N2 - Risk of second primary malignancy (SPM) is increasing. We aimed to assess the incidence and related risk factors of SPM among breast cancer (BC) patients from this nested case–control study using the SEER database. BC patients with SPM were identified as the case group and SPM-free patients were defined as the control group. Propensity score matching of cases with controls by the year of the first primary BC diagnosis was conducted at the ratio of 1:5, and 97,242 BC patients were enrolled from 1998 to 2013 after the matching. The incidence of SPM in BC patients stratified by age groups and cancer sites was compared to the general population using the adjusted standardized incidence ratio (SIR) and the risk factors for SPM were examined using Cox proportional hazard regressions. Our study showed BC patients had excess risk for SPM than the general population (adjusted SIR for all cancer sites = 12.94, p < 0.001) and the incidence of SPM among them decreased with age. The risk of SPM was significantly related to the following demographical and clinical variables: age (40–59 vs. 18–39, HR = 1.33; 60–79 vs. 18–39, HR = 2.39; ≥80 vs. 18–39, HR = 2.84), race (black vs. white, HR = 1.12), histological type (lobular BC vs. ductal BC, HR = 1.15), radiotherapy (HR = 1.33), marital status (married vs. single, HR = 0.88) and estrogen receptor status (positive vs. negative, HR = 0.85). Consistent results were found in subgroup analysis stratified by contralateral-breast SPMs and nonbreast SPMs.
AB - Risk of second primary malignancy (SPM) is increasing. We aimed to assess the incidence and related risk factors of SPM among breast cancer (BC) patients from this nested case–control study using the SEER database. BC patients with SPM were identified as the case group and SPM-free patients were defined as the control group. Propensity score matching of cases with controls by the year of the first primary BC diagnosis was conducted at the ratio of 1:5, and 97,242 BC patients were enrolled from 1998 to 2013 after the matching. The incidence of SPM in BC patients stratified by age groups and cancer sites was compared to the general population using the adjusted standardized incidence ratio (SIR) and the risk factors for SPM were examined using Cox proportional hazard regressions. Our study showed BC patients had excess risk for SPM than the general population (adjusted SIR for all cancer sites = 12.94, p < 0.001) and the incidence of SPM among them decreased with age. The risk of SPM was significantly related to the following demographical and clinical variables: age (40–59 vs. 18–39, HR = 1.33; 60–79 vs. 18–39, HR = 2.39; ≥80 vs. 18–39, HR = 2.84), race (black vs. white, HR = 1.12), histological type (lobular BC vs. ductal BC, HR = 1.15), radiotherapy (HR = 1.33), marital status (married vs. single, HR = 0.88) and estrogen receptor status (positive vs. negative, HR = 0.85). Consistent results were found in subgroup analysis stratified by contralateral-breast SPMs and nonbreast SPMs.
KW - breast cancer
KW - breast-conserving surgery
KW - radiotherapy
KW - risk factor
KW - second primary malignancy
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U2 - 10.1002/ijc.32259
DO - 10.1002/ijc.32259
M3 - Article
C2 - 30861567
AN - SCOPUS:85063357858
SN - 0020-7136
VL - 146
SP - 352
EP - 362
JO - International Journal of Cancer
JF - International Journal of Cancer
IS - 2
ER -