Epidemiology of Second Non-breast Primary Cancers among Survivors of Breast Cancer: A Korean Population–Based Study by the SMARTSHIP Group
- Author:
Haeyoung KIM
1
;
Su SSan KIM
;
Ji Sung LEE
;
Jae Sun YOON
;
Hyun Jo YOUN
;
Hyukjai SHIN
;
Jeong Eon LEE
;
Se Kyung LEE
;
Il Yong CHUNG
;
So-Youn JUNG
;
Young Jin CHOI
;
Jihyoung CHO
;
Sang Uk WOO
;
Author Information
- Publication Type:Original Article
- From:Cancer Research and Treatment 2023;55(2):580-591
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:This study aimed to evaluate the incidence and prognosis of second non-breast primary cancer (SNBPC) among Korean survivors of breast cancer.
Materials and Methods:Data from the Korean National Health Insurance Service were searched to identify women who received curative surgery for initial breast cancer (IBC) between 2003 and 2008 (n=64,340). Among them, patients with the following characteristics were excluded: other cancer diagnosis before IBC (n=10,866), radiotherapy before IBC (n=349), absence of data on sex or age (n=371), or male (n=248). Accordingly, data of 52,506 women until December 2017 were analyzed. SNBPC was defined as a newly diagnosed SNBPC that occurred 5 years or more after IBC diagnosis.
Results:The median follow-up time of all patients was 12.13 years. SNBPC was developed in 3,084 (5.87%) women after a median of 7.61 years following IBC diagnosis. The 10-year incidence of SNBPC was 5.78% (95% confidence interval [CI], 5.56 to 6.00). Higher SNBPC incidence was found in survivors with the following factors: old age at IBC diagnosis, low household income, and receiving combined chemotherapy with endocrine therapy, whereas receiving radiotherapy was related to a lower incidence of SNBPC (hazard ratio, 0.89; p < 0.01). Among the patients with SNBPC, the 5-year survival rate was 62.28% (95% CI, 65.53 to 69.02).
Conclusion:Approximately 5% of breast cancer survivors developed SNBPC within 10 years after IBC diagnosis. The risk of SNBPC was associated with patient’s age at IBC diagnosis, income level, and a receipt of systemic treatments.
