title: Second primary lung cancers among breast cancer patients treated with anti-estrogens have a longer cancer-specific survival.
abstract: OBJECTIVE
  Estrogen is thought to play an important role in lung cancer carcinogenesis and progression. The incidence and survival of second primary lung cancer among breast cancer patients with and without anti-estrogen therapy were evaluated.
  
  
  METHODS
  All women diagnosed with breast cancer and treated at the Sun Yat-Sen Cancer Center between January 2000 and December 2009 were included and followed-up for occurrence and/or death from lung cancer until December 2011.
  
  
  RESULTS
  Twenty-six women developed second primary lung cancer among 6,361 breast cancer patients. All but one were adenocarcinoma and none had a smoking habit. Seventeen (65.4%) patients had previously received anti-estrogen treatment. The relative risk of developing second primary lung cancer among those who have received anti-estrogens for breast cancer and those who have not was 1.01 (95% confidence interval (CI)=0.45~2.28; p=0.970). Second primary lung cancer patients who have received anti-estrogens had a longer cancer-specific survival (p=0.007). The multivariate Cox proportional hazards analysis showed that anti-estrogen therapy remained an independent prognostic factor with a hazard ratio of 0.11 (95% CI=0.01~0.97, p=0.002) for second primary lung cancer patients.
  
  
  CONCLUSIONS
  The results of this study further support the fact that estrogen adversely affects the prognosis of patients with lung cancer. However, the role of estrogen in lung cancer carcinogenesis remains to be determined.
authors: Division of Pulmonary and Critical Care Medicine, Sun Yat-Sen Cancer Center, Taipei, Taiwan, R.O.C. Department of Medicine, National Yang-Ming University Medical School, Taipei, Taiwan, R.O.C. lhhsu@kfsyscc.org.
authors: Li-Han
authors: LH
authors: Hsu
authors: Departments of Research, Sun Yat-Sen Cancer Center, Taipei, Taiwan, R.O.C.
authors: An-Chen
authors: AC
authors: Feng
authors: School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan, R.O.C.
authors: Shu-Huei
authors: SH
authors: Kao
authors: Division of Thoracic Surgery, Sun Yat-Sen Cancer Center, Taipei, Taiwan, R.O.C.
authors: Chia-Chuan
authors: CC
authors: Liu
authors: Department of Radiation Oncology, Sun Yat-Sen Cancer Center, Taipei, Taiwan, R.O.C.
authors: Stella Y C
authors: SY
authors: Tsai
authors: Department of Pathology, Sun Yat-Sen Cancer Center, Taipei, Taiwan, R.O.C.
authors: Li-Sun
authors: LS
authors: Shih
authors: Department of Medical Oncology, Sun Yat-Sen Cancer Center, Taipei, Taiwan, R.O.C.
authors: Nei-Min
authors: NM
authors: Chu
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D020847:Estrogen Receptor Modulators / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary*; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000503:physiopathology*; D016019:Survival Analysis
chemical_list: D020847:Estrogen Receptor Modulators
keywords: Breast cancer; estrogen; incidence; lung cancer; survival