Elsevier

Lung Cancer

Volume 22, Issue 1, October 1998, Pages 15-21
Lung Cancer

Effect of cigarette smoking on major histological types of lung cancer in men

https://doi.org/10.1016/S0169-5002(98)00068-3Get rights and content

Abstract

This study examined the effect of cigarette smoking parameters such as intensity, duration, age at initiation, and quitting on the development of different histological types of lung cancer in men. We used data from a case-control study conducted in Philadelphia between 1985 and 1987. Cases included 482 men with histologically confirmed lung cancer diagnosed in 15 selected hospitals in Philadelphia. Controls were selected from a neighborhood survey of men in Philadelphia conducted concurrently to the case recruitment. Most aspects of smoking were associated with all the major histological types of lung cancer. Number of cigarettes smoked per day was the strongest predictor of risk of developing lung cancer. Early age at initiation of smoking significantly increased the risk of small cell carcinoma (odds ratio=3.0; 95% CI, 1.1–8.4). Quitting smoking reduced the risk of squamous cell and adenocarcinoma; however, it did not affect the risk of small cell lung cancer. The findings of this study suggest the need for greater emphasis on smoking prevention programs, especially in adolescents.

Introduction

Lung cancer is the most common malignancy in the United States and is the leading cause of cancer deaths in males in the United States and world-wide [1]. The association between smoking and lung cancer is studied extensively and is well established. Almost 87–90% of lung cancer cases are attributable to cigarette smoking and smokers are 22 times more likely to die from lung cancer than non-smokers [2].

Although it is certain that tobacco smoking increases the risk of lung cancer, the aspects of smoking that determine the development of specific type of lung cancer have not been well understood. Tobacco smoking is associated with almost all the different histological types of lung cancer [3]; however, the strength of the association varies with the type of lung cancer. Most studies suggest that the strength of association between smoking and squamous cell carcinoma or small cell carcinoma is stronger than between smoking and adenocarcinoma. However, there is no consensus about the relative risk by histological type for duration of smoking or the amount smoked. Moreover, the effect of quitting smoking on the risk of the three major histological types of lung cancer is not clearly understood. Smoking at an early age is associated with increased risk of lung cancer 4, 5. However, little is known about the significance of age at the start of smoking for different histological types. In this analysis, we evaluated the relationships of age at the start of smoking, quantity smoked, and duration of smoking with various histological types of lung cancer.

Section snippets

Subjects and methods

The cases for this study included men with a newly diagnosed and histologically confirmed lung cancer admitted to one of the 15 hospitals in Philadelphia between 1985 and 1987. Trained medical staff working under the direction of one of the co-authors (Hari H. Dayal) were assigned to visit the hospitals once a week to review pathology logs in order to identify newly diagnosed male lung cancer cases. Since, by design, the study was restricted to cases from Philadelphia, cases identified from

Results

There were a total of 482 cases (342 Whites, 140 Blacks) and 1094 matched controls. The mean age of the cases was 65.7 years (range, 36–89 years) and did not vary markedly by histological type. The mean age of the control subject was 64.9 years (range, 36–88 years). Table 1 shows the distribution of cases and control subjects by demographic variables. Cases of adenocarcinoma were slightly younger than cases of other types of lung cancer. There were no significant differences between cases and

Discussion

This study examined the influence of various smoking parameters on the risk of different histological types of lung cancers. All smoking-related variables (age at the start of smoking, number of cigarettes smoked per day, duration of smoking, inhalation pattern, smoking filtered or non-filtered cigarettes) were significantly associated with the risk of lung cancer (all histologies combined). These findings are generally in agreement with other case-control studies 4, 5, 10, 11, 12, 13, 14, 15.

References (29)

  • KT Hegmann et al.

    The effect of age at smoking initiation on cancer risk

    Epidemiology

    (1993)
  • NE Breslow et al.

    Estimation of multiple relative risk functions in matched case control studies

    Am J Epidemiol

    (1978)
  • Breslow NE, Day NE. The analysis of case-control studies. In: Statistical methods in cancer research, vol. 1. IARC SCI...
  • SAS Institute Inc. SAS/STAT user’s guide version 6, 4th ed., vol 2. Cary, NC: SAS Institute Inc.,...
  • Cited by (0)

    1

    Formerly at Fox Chase Cancer Centre, Philadelphia.

    View full text