Lung cancer incidence in never smokers

Dietary boron and hormone replacement therapy as risk factors for lung cancer in women

Hormone replacement therapy (HRT) may reduce lung cancer risk. Dietary boron may have actions similar to those of HRT; however, no previous study has reported the associations between dietary boron intake and lung cancer risk or the joint effects of boron intake and HRT use on lung cancer risk. The authors examined the associations between boron intake and the joint effects of boron intake and HRT on lung cancer risk in women. In an ongoing case-control study in Houston, Texas (July 1995 through April 2005, end date for this analysis), 763 women were diagnosed with lung cancer, and 838 were matched healthy controls with data on both diet and HRT. Multiple logistic regression analyses were conducted to assess the associations between dietary boron and HRT with lung cancer risk. After adjustment for potential confounders, the odds ratios for lung cancer with decreasing quartiles of dietary boron intake were 1.0, 1.39 (95% confidence interval (CI): 1.02, 1.90), 1.64 (95% CI: 1.20, 2.24), and 1.95 (95% CI: 1.42, 2.68) mg/day, respectively, for all women (p(trend) < 0.0001). In joint-effects analyses, compared with women with high dietary boron intake who used HRT, the odds ratio for lung cancer for low dietary boron intake and no HRT use was 2.07 (95% CI: 1.53, 2.81). Boron intake was inversely associated with lung cancer in women, whereas women who consumed low boron and did not use HRT were at substantial increased odds.

Passive smoking and lung cancer in Japanese non-smoking women: a prospective study

Although smoking is a major cause of lung cancer, the proportion of lung cancer cases among Japanese women who never smoked is high. As the prevalence of smoking in Japan is relatively high in men but low in women, the development of lung cancer in non-smoking Japanese women may be significantly impacted by passive smoking. We conducted a population-based prospective study established in 1990 for Cohort I and in 1993 for Cohort II. The study population was defined as all residents aged 40-69 years at the baseline survey. 28,414 lifelong non-smoking women provided baseline information on exposure to tobacco smoke from their husband, at the workplace and during childhood. Over 13 years of follow-up, 109 women were newly diagnosed with lung cancer, of whom 82 developed adenocarcinoma. Compared with women married to never smokers, hazard ratio (HR) [95% confidence interval (CI)] for all lung cancer incidence in women who lived with a smoking husband was 1.34 (95% CI 0.81-2.21). An association was clearly identified for adenocarcinoma (HR 2.03, 95% CI 1.07-3.86), for which dose-response relationships were seen for both the intensity (p for trend = 0.02) and amount (p for trend = 0.03) of the husband's smoking. Passive smoking at the workplace also increased the risk of lung cancer (HR 1.32, 95% CI 0.85-2.04). Moreover, a higher risk of adenocarcinoma was seen for combined husband and workplace exposure (HR 1.93, 95% CI 0.88-4.23). These findings confirm that passive smoking is a risk factor for lung cancer, especially for adenocarcinoma among Japanese women.

Analysis of lung cancer incidence in the Nurses' Health and the Health Professionals' Follow-Up Studies using a multistage carcinogenesis model

We analyzed lung cancer incidence among non-smokers, continuing smokers, and ex-smokers in the Nurses Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS) using the two-stage clonal expansion (TSCE) model. Age-specific lung cancer incidence rates among non-smokers are identical in the two cohorts. Within the framework of the model, the main effect of cigarette smoke is on the promotion of partially altered cells on the pathway to cancer. Smoking-related promotion is somewhat higher among women, whereas smoking-related malignant conversion is somewhat lower. In both cohorts the relative risk for a given daily level of smoking is strongly modified by duration. Among smokers, the incidence in NHS relative to that in HPFS depends both on smoking intensity and duration. The age-adjusted risk is somewhat larger in NHS, but not significantly so. After smokers quit, the risk decreases over a period of many years and the temporal pattern of the decline is similar to that reported in other recent studies. Among ex-smokers, the incidence in NHS relative to that in HPFS depends both on previous levels of smoking and on time since quitting. The age-adjusted risk among ex-smokers is somewhat higher in NHS, possibly due to differences in the age-distribution between the two cohorts.

Lung cancer in never smokers--a different disease

Although most lung cancers are a result of smoking, approximately 25% of lung cancer cases worldwide are not attributable to tobacco use, accounting for over 300,000 deaths each year. Striking differences in the epidemiological, clinical and molecular characteristics of lung cancers arising in never smokers versus smokers have been identified, suggesting that they are separate entities. This Review summarizes our current knowledge of this unique and poorly understood disease.

Erlotinib as a Single Agent in Select Subsets of Patients with Advanced Non–Small-Cell Lung Cancer

Erlotinib is an orally active inhibitor of the epidermal growth factor receptor that is effective for the treatment of non-small-cell lung cancer (NSCLC). Patients with a poor performance status (PS) of 2 constitute up to 40% of advanced NSCLC. This group of patients have a lower life expectancy and are thought to have a greater degree of treatment-related toxicity. The clinical benefit on 238 patients with poor PS included in an open-label, nonrandomized, phase II trial of erlotinib in advanced/metastatic NSCLC was 57.58% defined as complete response plus partial response plus stable disease. Median time to progression was 2.9 months. This review will summarize available data about erlotinib on patients with a PS of 2.