reduced lung cancer mortality risk among breast cancer patients treated with anti-estrogens
DESCRIPTION
Reduced Lung Cancer Mortality Risk Among Breast Cancer Patients Treated With Anti-Estrogens. Rapiti E et al. SABCS 2009;Abstract 35. Introduction. - PowerPoint PPT PresentationTRANSCRIPT
Reduced Lung Cancer Mortality Risk Among Breast Cancer Patients Treated With Anti-Estrogens
Rapiti E et al.SABCS 2009;Abstract 35.
Introduction
Women in the post-intervention period of the Women’s Health Initiative (WHI) trial who were assigned to combined hormone replacement therapy had a higher risk of cancer compared to those on placebo (JAMA 2008;299:1036).
Post-hoc analysis of the WHI trial demonstrated increased lung cancer mortality in women administered postmeno-pausal hormone replacement therapy of estrogen with progesterone versus placebo (Lancet 2009;374:1243).– 73 (0.11%) versus 40 (0.06%) deaths (hazard ratio=1.71,
p=0.01)
Current study objective:– Assess if anti-estrogen therapy in patients with breast
cancer is associated with a decreased lung cancer mortality risk.
Rapiti E et al. SABCS 2009;Abstract 35.
Methods
Study group of 6,655 patients diagnosed with breast cancer between 1980 to 2003 were identified from the Geneva Cancer Registry.– Patients having received anti-estrogens: 3,066 (46%)
Lung cancer incidence and mortality were followed until December 31, 2007, and were compared to age-, sex- and period-adjusted population rates using:– Standardized incidence ratios (SIRs)– Standardized mortality ratios (SMRs)
Subgroup analyses performed by period and smoking history.– Prior to 1990, women were less likely to have been
administered anti-estrogen therapy, and related data on smoking history were limited.
Rapiti E et al. SABCS 2009;Abstract 35.
Smoking History of Study Population Versus General Female Population
Smoking History
Anti-Estrogen Use
General Female Population*
Yes(n=2,105)
No(n=1,217)
Smoker 30% 29% 29%
Ex-smoker 14% 13% 16%
Non-smoker 57% 58% 55%
*Enquête sur la Consommation de Tabac en Suisse. Rapport 2001/2002. Zurich University 2003.
Rapiti E et al. SABCS 2009;Abstract 35.
Risk of Developing Lung CancerAfter Breast Cancer
All Patients
Anti-estrogen
therapy
Incidence rates*
Observed cases
Expected cases
SIR p-value
Yes 55.4 12 19.1 0.63 0.058
No 78.8 28 25.0 1.12 0.294
Patients Diagnosed from 1990
Anti-estrogen
therapy
Incidence rates*
Observed cases
Expected cases
SIR p-value
Yes 56.7 11 17.2 0.64 0.123
No 79.8 11 9.9 1.11 0.491
Rapiti E et al. SABCS 2009;Abstract 35.
*Age-standardized (Geneva population distribution) incidence rates per 100,000 person-years.
Risk of Death From Lung CancerAfter Breast Cancer
All Patients
Anti-estrogen
therapy
Mortality rates*
Observed cases
Expected cases
SMR p-value
Yes 9.2 2 15.3 0.13 <0.0001
No 45.0 16 21.1 0.76 0.158
Patients Diagnosed from 1990
Anti-estrogen
therapy
Mortality rates*
Observed cases
Expected cases
SMR p-value
Yes 10.3 2 13.3 0.15 <0.001
No 36.2 5 7.7 0.65 0.340
Rapiti E et al. SABCS 2009;Abstract 35.
*Age-standardized (Geneva population distribution) mortality rates per 100,000 person-years.
Conclusions
Patients treated with anti-estrogens for breast cancer have a significantly reduced risk of death from lung cancer compared to the general population.
Residual confounding cannot be excluded due to the observational nature of the study.
This study further supports the hypothesis that estrogen plays a role in lung cancer prognosis.
Rapiti E et al. SABCS 2009;Abstract 35.