Comparative study of control selection in a national population-based case-control study: Estimating risk of smoking on cancer deaths in Chinese men

Menopausal Hormone Therapy use and breast cancer risk by receptor subtypes: Results from the New South Wales Cancer Lifestyle and EvaluAtion of Risk (CLEAR) study

Breast cancer risk is increased with current Menopausal Hormone Therapy (MHT) use, with higher risks reported for ER+ (Estrogen Receptor positive), and ER+/PR+ (Estrogen and Progesterone Receptor positive) breast cancers than those of ER- and ER-/PR- status, respectively. There is limited evidence to suggest MHT use is associated with the specific subtype characterised as ER+/PR+/HER2- (Estrogen and Progesterone Receptor positive and Human Epidermal growth factor Receptor2 negative) status. This study aims to investigate the MHT-breast cancer relationship for breast cancer tumor receptor subtypes defined by ER expression alone, by ER and PR expression only and by joint expression of ER, PR, and HER2. Analyses compared 399 cancer registry-verified breast cancer cases with receptor status information and 324 cancer-free controls. We used multinomial logistic regression to estimate adjusted odds ratios (aORs) and 95% Confidence Intervals (CI) for current and past versus never MHT use, for subgroups defined by tumor receptor expression. Current, but not past, use of MHT was associated with an elevated risk of ER+ breast cancer (aOR = 2.04, 95%CI: 1.28-3.24) and ER+/PR+ breast cancer (aOR = 2.29, 1.41-3.72). Current MHT use was also associated with an elevated risk of the ER+/PR+/HER2- subtype (aOR = 2.30, 1.42-3.73). None of the other subtypes based on ER, ER/PR or ER/PR/HER2 expression were significantly associated with current MHT use in this analysis. Current, but not past, use of MHT increases the risk of breast cancer, with consistently higher risks reported for ER+ and ER+/PR+ subtypes and mounting evidence regarding the specific ER+/PR+/HER2- subtype. Our findings contribute to quantification of the effects of MHT, and support efforts to articulate the receptor-mediated mechanisms by which MHT increases the risk of breast cancer.

Smoking and adult glioma: a population-based case-control study in China

BACKGROUND

Smoking increases the risk of numerous cancers; however, an association of smoking with adult gliomas has not been found in a population.

METHODS

This case-control study included 4556 glioma cases (ICD-9 code 191.0-191.9) aged ≥ 30 years and 9112 controls from a national survey of smoking and mortality in China in 1989-1991. Controls from 325 255 surviving spouses of all-cause deaths were randomly assigned to cases in each of 103 areas according to sex and age groups at a ratio of 2:1. Smoking information was ascertained retrospectively by interviewing surviving spouses.

RESULTS

After adjustment for confounders, smoking increased the risk of glioma deaths by 11% (odds ratio [OR] = 1.11; 95% confidence interval [CI]: 1.03-1.21). Compared with non-smokers; the increased risk was 9% (OR = 1.09; 95% CI: 0.99-1.20) in men and 16% (OR = 1.16; 95% CI: 1.00-1.36) in women. The risk increased with age and doses. For individuals aged ≥ 50 years, smoking was associated with higher risk of glioma death by 25% (OR = 1.25; 95% CI: 1.15-1.38); this increased risk for smokers who smoked ≥ 20 cigarettes daily for ≥ 30 years was 53% (OR = 1.53; 95% CI: 1.34-1.74). There were similar findings in both men and women and with either pathology-based or non-pathology-based comparisons.

CONCLUSIONS

This study indicates that smoking is associated with glioma deaths in the Chinese population. Long-term heavy smoking could be a factor for risk stratification in individuals attending brain tumor clinics.

Contributions of major smoking-related diseases to reduction in life expectancy associated with smoking in Chinese adults: a cross-sectional study

BACKGROUND

Cigarette smoking is a prominent risk factor for a wide range of diseases. The current study aimed to evaluate the impact of smoking on deaths from major smoking-related diseases (neoplasms, vascular diseases and respiratory diseases) in Chinese adults by estimating the potential gains in life expectancy (LE) that would accrue from eliminating deaths from these diseases, and to determine the contribution of each disease to the reduction in LE associated with smoking.

METHODS

Two cohorts of Chinese smokers and non-smokers were constructed from a retrospective national mortality survey that had been conducted in 1989-1991 and included one million all-cause deaths among adults during 1986-1988 in 103 geographical regions. For each cohort, potential gains in LE by eliminating deaths from each major smoking-related disease were estimated. The contributions of each disease to smoking-associated reduction in LE were assessed using the LE decomposition approach.

RESULTS

Among the major smoking-related diseases, it was estimated that elimination of vascular diseases would provide the greatest potential gain in LE (years), regardless of smoking status. The gains for smokers versus non-smokers in populations of urban men, urban women, rural men and rural women aged 35 years were 3.5 vs. 4.3, 3.8 vs. 4.1, 2.4 vs. 3.0, and 2.6 vs. 2.9 years, respectively. Respiratory diseases contributed most to smoking-associated LE reductions in urban women, rural men and rural women of 43.6%, 46.4%, and 62.9%, respectively. In urban men, neoplasms contributed most to smoking-associated LE reduction, their contribution being estimated as 45.8%.

CONCLUSIONS

Respiratory disease has the greatest influence on the LE reduction associated with smoking. Thus, smoking prevention could significantly reduce deaths from respiratory disease and improve LE.

Smoking, environmental tobacco smoke, and aspirin-exacerbated respiratory disease

BACKGROUND

Tobacco smoke is a widely recognized environmental pollutant and is a major public health hazard worldwide. Although environmental tobacco smoke (ETS) has a clear link with many conditions, including asthma, ear infections, and sinus cancer, evidence related to aspirin-exacerbated respiratory disease (AERD) requires further investigation.

OBJECTIVE

To investigate whether active smoke or ETS exposures are associated with an increased risk of developing AERD.

METHODS

A total of 260 patients with AERD were enrolled in a case-control study with their respective asymptomatic spouses serving as matched controls. Multiple logistic regression analysis was used to examine the association of AERD with active smoking and ETS, adjusted for age, sex, and location of childhood residence.

RESULTS

The AERD case patients were more likely to have ever smoked actively when compared with controls (odds ratio [OR], 1.54; 95% confidence interval [CI], 1.04-2.28). A significant association (OR, 3.46; 95% CI, 2.22-5.39) was found between childhood ETS exposure and AERD. If a patient was exposed to ETS during both childhood and adulthood, results showed an OR of 5.09 for developing AERD (95% CI, 2.75-9.43). However, no statistically significant association between AERD and ETS only during adulthood was found (OR, 1.60; 95% CI, 0.75-3.40), suggesting that the combined effect of childhood and adulthood ETS may be augmented by the prior childhood exposure.

CONCLUSIONS

Active smoking and childhood ETS exposure are associated with increased odds of developing AERD. In particular, combined childhood and adulthood exposure had major effects. This study suggests that ETS is at least one contributor to the syndrome of AERD.

Smoking and health: association between telomere length and factors impacting on human disease, quality of life and life span in a large population-based cohort under the effect of smoking duration

Reactive oxygen species (ROS) are of primary importance as they cause damage to lipids, proteins, and DNA either endogenously by cellular mechanism, or through exogenous exposure to environmental injury factors, including oxidation insult factors, such as tobacco smoke. Currently 46.3 million adults (25.7 percent of the population) are smokers. This includes 24 million men (28.1 percent of the total) and more than 22 million women (23.5 percent). The prevalence is highest among persons 25-44 years of age. Cigarette smokers have a higher risk of developing several chronic disorders. These include fatty buildups in arteries, several types of cancer and chronic obstructive pulmonary disease (lung problems). As peripheral leukocytes have been the main target of human telomere research, most of what is known about human telomere dynamics in vivo is based on these cells. Leukocyte telomere length (TL) is a complex trait that is shaped by genetic, epigenetic, and environmental determinants. In this article, we consider that smoking modifies leukocyte TL in humans and contributes to its variability among individuals, although the smoking effect on TL and its relation with other metabolic indices may accelerate biological aging and development of smoking-induced chronic diseases in a large human population-based cohorts with smoking behavior. Recent studies confirmed that individuals with shorter telomeres present a higher prevalence of arterial lesions and higher risk of cardiovascular disease mortality. This study originally suggests that efficient therapeutic protection of TL and structure in response to stresses that are known to reduce TL, such as oxidative damage or inflammation associated with tobacco smoking, would lead to better telomere maintenance. Recently, we have discovered the potential use of telomere-restorative imidazole-containing dipeptide (non-hydrolized carnosine, carcinine) based therapy for better survival of smokers. We conclude that a better therapeutic or nutritional maintenance of TL may confer healthy aging in smokers and exceptional longevity in regularly ROS-exposed human survivors.