J Breast Cancer.  2015 Mar;18(1):8-15. 10.4048/jbc.2015.18.1.8.

Survival Improvement in Korean Breast Cancer Patients Due to Increases in Early-Stage Cancers and Hormone Receptor Positive/HER2 Negative Subtypes: A Nationwide Registry-Based Study

• You JM
• Kim YG
• Moon HG
• Nam SJ
• Lee JW
• Lim W
• Lee MR
• Noh DY
• Han W

• KMID: 2286331
• DOI: http://doi.org/10.4048/jbc.2015.18.1.8

Abstract

PURPOSE
The aim of this study was to investigate whether the observed changes over time in the survival rates vary according to the intrinsic subtypes of breast cancer diagnosed.
METHODS
Data from 46,320 breast cancer patients in the Korean Breast Cancer Registry who underwent surgery between 1999 and 2006 were reviewed. Among them, results from 25,887 patients with available data about the status of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) were analyzed. Patients were classified into two cohorts according to the year in which they underwent surgery: 1999-2002 and 2003-2006.
RESULTS
The patients treated in the latter time period showed significantly better overall survival (OS) compared with those in the former period when adjusted for follow-up duration. The proportion of hormone receptor+/HER2-subtype and stage I breast cancer were significantly higher in the latter period (47.4% vs. 54.6%, p<0.001; 31.0% vs. 39.6%, p<0.001, respectively). Improvement in OS between the former and latter periods was seen in all subtypes of breast cancer, including triple-negative cancers (all p-values <0.001 in univariate and multivariate analyses).
CONCLUSION
Improvement in survival in Korean breast cancer patients over the study years is being observed in all subtypes of breast cancer, implying that increases in both early-stage detection and the proportion of less aggressive cancers contribute to this improvement.

Keyword

Breast neoplasms; Clinical characteristics; Korea; Registries

MeSH Terms

Breast Neoplasms*
Cohort Studies
Estrogens
Follow-Up Studies
Humans
Korea
Receptor, Epidermal Growth Factor
Receptors, Progesterone
Registries
Survival Rate
Estrogens
Receptor, Epidermal Growth Factor
Receptors, Progesterone

Figure

• 

  Figure 1 Study enrollment scheme. HER2=human epidermal growth factor receptor 2; ER=estrogen receptor; PR=progesterone receptor; IHC=immunohistochemistry; AJCC=American Joint Committee on Cancer.

• 

  Figure 2 Chronological changes in Korean breast cancer during 1999 to 2006. The incidence of Korean breast cancer during 1999 to 2006 demonstrated by the subtype (A) and the stage (B). Proportional change of Korean breast cancer during 1999 to 2006 demonstrated by the subtype (C) and the stage (D). HR=hormone receptor; HER2=human epidermal growth factor receptor 2.

• 

  Figure 3 Relative survival plot of Korean breast cancer according to the subtype. (A) HR+/HER2-. (B) HR+/HER2+. (C) HR-/HER2+. (D) HR-/HER2-. HR=hormone receptor; HER2=human epidermal growth factor receptor 2.

• 

  Figure 4 Kaplan-Meier survival plot of the HR+ (ER+ and/or PR+) subtype tumor according to the use of aromatase inhibitors (AIs). There is nonsignificant survival difference between the selective estrogen receptor modulator (SERM)-only use group and AIs use group (p=0.206). HR=hormone receptor; ER=estrogen receptor; PR=progesterone receptor; CI=confidence interval.

Reference

1. Ko BS, Noh WC, Kang SS, Park BW, Kang EY, Paik NS, et al. Changing patterns in the clinical characteristics of Korean breast cancer from 1996-2010 using an online nationwide breast cancer database. J Breast Cancer. 2012; 15:393–400.

2. Korean Breast Cancer Society. Clinical characteristics of breast cancer patients in Korea in year 2000. J Korean Breast Cancer Soc. 2002; 5:217–224.

3. The Korean Breast Cancer Society. Nationwide Korean breast cancer data of 2002 The Korean Breast Cancer Society. J Korean Breast Cancer Soc. 2004; 7:72–83.

4. Jung YS, Na KY, Kim KS, Ahn SH, Lee SJ, Park HK, et al. Nation-wide Korean breast cancer data from 2008 using the breast cancer registration program. J Breast Cancer. 2011; 14:229–236.

5. The Korean Breast Cancer Society. Survival analysis of Korean breast cancer patients diagnosed between 1993 and 2002 in Korea: a nationwide study of the cancer registry. J Breast Cancer. 2006; 9:214–229.

6. Perou CM, Sørlie T, Eisen MB, van de Rijn M, Jeffrey SS, Rees CA, et al. Molecular portraits of human breast tumours. Nature. 2000; 406:747–752.

7. Sørlie T, Perou CM, Tibshirani R, Aas T, Geisler S, Johnsen H, et al. Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications. Proc Natl Acad Sci U S A. 2001; 98:10869–10874.

8. Ahn SH, Son BH, Kim SW, Kim SI, Jeong J, Ko SS, et al. Poor outcome of hormone receptor-positive breast cancer at very young age is due to tamoxifen resistance: nationwide survival data in Korea--a report from the Korean Breast Cancer Society. J Clin Oncol. 2007; 25:2360–2368.

9. Shin HR, Won YJ, Jung KW, Kong HJ, Yim SH, Lee JK, et al. Nationwide cancer incidence in Korea, 1999.2001: first result using the national cancer incidence database. Cancer Res Treat. 2005; 37:325–331.

10. Hausauer AK, Keegan TH, Chang ET, Clarke CA. Recent breast cancer trends among Asian/Pacific Islander, Hispanic, and African-American women in the US: changes by tumor subtype. Breast Cancer Res. 2007; 9:R90.

11. Yamashita H, Iwase H, Toyama T, Takahashi S, Sugiura H, Yoshimoto N, et al. Estrogen receptor-positive breast cancer in Japanese women: trends in incidence, characteristics, and prognosis. Ann Oncol. 2011; 22:1318–1325.

12. Yang XR, Chang-Claude J, Goode EL, Couch FJ, Nevanlinna H, Milne RL, et al. Associations of breast cancer risk factors with tumor subtypes: a pooled analysis from the Breast Cancer Association Consortium studies. J Natl Cancer Inst. 2011; 103:250–263.

13. Tamimi RM, Colditz GA, Hazra A, Baer HJ, Hankinson SE, Rosner B, et al. Traditional breast cancer risk factors in relation to molecular subtypes of breast cancer. Breast Cancer Res Treat. 2012; 131:159–167.

14. Yoo KY, Kim Y, Park SK, Kang D. Lifestyle, genetic susceptibility and future trends of breast cancer in Korea. Asian Pac J Cancer Prev. 2006; 7:679–682.

15. Kim Y, Choi JY, Lee KM, Park SK, Ahn SH, Noh DY, et al. Dose-dependent protective effect of breast-feeding against breast cancer among ever-lactated women in Korea. Eur J Cancer Prev. 2007; 16:124–129.

16. Jung YS, Na KY, Kim KS, Ahn SH, Lee SJ, Park HK, et al. Nation-wide Korean breast cancer data from 2008 using the breast cancer registration program. J Breast Cancer. 2011; 14:229–236.