Cancer Res Treat.  2017 Oct;49(4):1114-1126. 10.4143/crt.2016.528.

Education Level Is a Strong Prognosticator in the Subgroup Aged More Than 50 Years Regardless of the Molecular Subtype of Breast Cancer: A Study Based on the Nationwide Korean Breast Cancer Registry Database

• Hwang KT
• Noh W
• Cho SH
• Yu J
• Park MH
• Jeong J
• Lee HJ
• Kim J
• Oh S
• Kim YA
• Korean Breast Cancer Society

• KMID: 2394830
• DOI: http://doi.org/10.4143/crt.2016.528

Abstract

PURPOSE
This study investigated the role of the education level (EL) as a prognostic factor for breast cancer and analyzed the relationship between the EL and various confounding factors.
MATERIALS AND METHODS
The data for 64,129 primary breast cancer patients from the Korean Breast Cancer Registry were analyzed. The EL was classified into two groups according to the education period; the high EL group (≥ 12 years) and low EL group (< 12 years). Survival analyses were performed with respect to the overall survival between the two groups.
RESULTS
A high EL conferred a superior prognosis compared to a low EL in the subgroup aged > 50 years (hazard ratio, 0.626; 95% confidence interval [CI], 0.577 to 0.678) but not in the subgroup aged ≤ 50 years (hazard ratio, 0.941; 95% CI, 0.865 to 1.024). The EL was a significant independent factor in the subgroup aged > 50 years according to multivariate analyses. The high EL group showed more favorable clinicopathologic features and a higher proportion of patients in this group received lumpectomy, radiation therapy, and endocrine therapy. In the high EL group, a higher proportion of patients received chemotherapy in the subgroups with unfavorable clinicopathologic features. The EL was a significant prognosticator across all molecular subtypes of breast cancer.
CONCLUSION
The EL is a strong independent prognostic factor for breast cancer in the subgroup aged > 50 years regardless of the molecular subtype, but not in the subgroup aged ≤ 50 years. Favorable clinicopathologic features and active treatments can explain the main causality of the superior prognosis in the high EL group.

Keyword

Breast neoplasms; Education; Educational status; Prognosis; Survival analysis

MeSH Terms

Breast Neoplasms*
Breast*
Drug Therapy
Education*
Educational Status
Humans
Mastectomy, Segmental
Multivariate Analysis
Prognosis
Survival Analysis

Figure

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  Fig. 1. Overall survival curves according to the education period (A) and education level (B) in all subjects. a)Statistical significance.

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  Fig. 2. Subgroup analyses with a forest plot for the effects of the education level with respect to the overall survival according to the clinicopathologic characteristics in all subjects. In the forest plot, a HR value less than 1 favors a high EL against low EL. CI, confidence interval; HER2, human epidermal growth factor receptor 2; EL, education level.

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  Fig. 3. Overall survival curves according to the education period (A) and education level (B) in the subgroup aged > 50 years. a)Statistical significance.

Reference

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