Influence of Type of Cigarette on Peripheral versus Central Lung Cancer

Abstract

Objectives: Adenocarcinoma has replaced squamous cell carcinoma as the most common cell type of lung cancer in the United States. It has been proposed that this shift is due to the increased use of filter and lower-tar cigarettes, resulting in increased delivery of smoke to peripheral regions of the lungs, where adenocarcinoma usually occurs. We reviewed radiologic data to evaluate the hypothesis that tumors in smokers of cigarettes with lower-tar yield are more likely to occur peripherally than tumors in smokers of higher-yield cigarettes. Methods: At two urban academic medical centers, we reviewed computed tomographic scans, chest radiographs, and medical records to assign tumor location (peripheral or central) for 330 smokers diagnosed with carcinoma of the lung between 1993 and 1999. We compared the proportion of tumors in a peripheral versus central location by lifetime filter use and average lifetime tar rating (<21 and z z z21 mg). Results: Tumor location (69% peripheral and 31% central) was unrelated to cigarette filter use. Smokers of cigarettes with lower-tar ratings were more likely than those with higher ratings to have peripheral rather than central tumors (odds ratio, 1.76; 95% confidence interval, 0.89-3.47). When restricted to subjects with adenocarcinoma or squamous cell carcinoma, the odds ratio (95% confidence interval) was 2.31 (1.05-5.08).

Ablation of Liver X receptors α and β leads to spontaneous peripheral squamous cell lung cancer in mice

“…On the basis of the site of the primary cancer, squamous cell lung cancer is described as central (CSCCa) or peripheral (PSCCa). The incidence of PSCCa is increasing and is reported to be approximately 50% of squamous cell lung cancer (3)(4)(5)(6). Although the etiology of squamous cell lung cancer is not known, smoking and chronic lung inflammation have been recognized as predisposing factors (7).…”

Does endobronchial lesion affect the lymph node status in non-small cell lung cancer?

“…[13] In their study, Watanabe et al [14] showed that the majority of the histological types of peripheral tumors were adenocarcinomas. In a study by Brooks et al, [15] the frequency of SCCs was found to be increasing in central tumors. In our study, SCC was seen more than adenocarcinoma in endobronchial tumors (85.6% vs. 9.8%) and the difference in between was statistically significant.…”

Possible Explanations for the Observed Rise in the Incidence of Lung Adenocarcinoma relative to that of Lung Squamous Cell Carcinoma

“…Another reason is that epidemiological studies show no overall evidence of any increase in the risk of AdC associated with filter vs. plain or lower vs. higher tar cigarettes [5,[9][10][11][12]. Low tar filter cigarettes are associated with a small reduction in risk of SqCC, but not enough to explain the observed large rise over time in the frequency of AdC relative to SqCC.…”

“…The argument that the switch to lower tar filtered cigarettes from the older, higher tar, plain cigarettes has been responsible for the rise in the incidence of adenocarcinoma (AdC) and in the ratio of AdC to squamous cell carcinoma (SqCC) is one that has been made previously on various occasions, [2][3][4] and has been supported by various researchers [5,6].…”