Surgical treatment or radiation therapy is the treatment of choice for early stages of cancer. The overall 5-year relative survival rate from lung cancer was 16% in 2006. Lung cancer survival is worse for men compared with women and blacks compared with whites. For example, 5-year lung cancer survival was 18% lower in black men compared with white men (11.3% vs. 13.8%, respectively) and 23% lower in black women compared with white women (14.4% vs. 18.6%, respectively).
The hypothesis has been proposed that women may be more susceptible than men to smoking-caused lung cancer. However, the results of studies that have compared the association between smoking and lung cancer in men and women using appropriate comparisons do not support this hypothesis.
The results of the Multi-Ethnic Cohort Study indicated that for a given degree of cigarette smoking, African Americans had a higher risk of lung cancer compared with other racial/ethnic groups. Menthol cigarettes have been hypothesized as one potential factor contributing to the observed greater susceptibility to smoking-caused lung cancer in African Americans, but menthol cigarettes have not been observed to be associated with a higher risk of lung cancer than nonmenthol cigarettes.[7,8]
Cigarette smoking is the primary risk factor
The epidemic of lung cancer in the 20th century was primarily due to increases in cigarette smoking, the predominant cause of lung cancer. The threefold variation in lung cancer mortality rates across the United States more or less parallels long-standing state-specific differences in the prevalence of cigarette smoking. For example, average annual age-adjusted lung cancer death rates for 1996 to 2000 were highest in Kentucky (78 deaths per 100,000 individuals) where 31% were current smokers in 2001; whereas the lung cancer death rates were lowest in Utah (26 deaths per 100,000 individuals), which had the lowest prevalence of cigarette smoking (13%).
The biology of carcinogenesis
Understanding the biology of carcinogenesis is crucial to the development of effective prevention and treatment strategies. Two important concepts in this regard are the multistep nature of carcinogenesis and the diffuse field-wide carcinogenic process. Epithelial cancers in the lung appear to develop in a series of steps extending over years. Epithelial carcinogenesis is conceptually divided into three phases: initiation, promotion, and progression. This process has been inferred from human studies identifying clinical-histological premalignant lesions (e.g., metaplasia and dysplasia). The concept of field carcinogenesis is that multiple independent neoplastic lesions occurring within the lung can result from repeated exposure to carcinogens, primarily tobacco. Patients developing cancers of the aerodigestive tract secondary to cigarette smoke also are likely to have multiple premalignant lesions of independent origin within the carcinogen-exposed field. The concepts of multistep and field carcinogenesis provide a model for prevention studies.