Smoking Habits in Lung-Cancer Proband Families and Comparable Control Families

SUMMARY The pattern of the familial smoking behavior was analyzed and compared between parents, siblings, and children of 270 lung cancer probands and the counterparts of 270 controls selected within the same community. The information regarding lifetime smoking experience was ascertained for 90 percent of all living and dead relatives being studied. The distribution of parents, siblings, and children by year of birth as well as the size of sibship and of family were comparab1e between the two family populations. With respect to cigarette smoking among the index subjects the following findings may be of interest: 1) Smoking at young ages is related to lung cancer. 2) The amount of daily sllloking (one pack or Illore) is related to lung cancer. 3) The duration of Sllloking (40 years or Illore) is related to lung cancer. Three different aspects of cigarette sllloking alllong the relatives were analyzed with the following results: 1) The relatives of the lung cancerprobands are Illore likely to be slllokers than those of the controls. 2) About 40 percent of the case relatives are slllokers regardless of the sllloking status of the probands; in contrast, 40 percent of those control relatives whose index subjects are slllokers, as cOlllpared with 30 percent of those control relatives whose index subjects are nonslllokers, are slllokers. 3) In both proband and control falllilies, children are Illore likely to be slllokers if their parents are slllokers. The results of our analyses do not seelll to support R. A. Fisher's "collllllon genotype" hypothesis regarding lung cancer and sllloking behavior.-J Nat Cance