Do the Number of Cigarettes Smokes per Day Contribute to the Incident of Malignant Cancer?

Background: The incident of malignant cancer due to smoking habit becomes a public health problem especially in the developing countries. Active smokers neglect to stop smoking even though various studies proved that smoking increases the risk of cancer. While, previous studies have assessed the incident risk of cancer but have not performed the validity of the measurement. The aim of this study is to know the number of cigarettes that contribute to the incidence of malignant cancer. Methods: A study with retrospective cohort design has been conducted by using a set of public data of Indonesia Family Life Survey (IFLS) in 2007 and 2014. All active smokers (n= 748) who were in good health condition in 2007, were traced in 2014 and then being diagnosed with cancer with considering age, gender, healthy eating habit, and regular physical activity. Data has been analysed by using logistic regression by performing Adjusted Risk Ratio (ARR) and the result of validity measurement. Results: The incident of malignant cancer in 2014 were skin, liver, stomach and oral cavity. Smoking 21-30 per day in 2007 were significantly increased risk of having malignant cancer in 2014 at ARR: 6.88; SE:6.13 with the accuracy were 93.8%. The risk and accuracy were higher if smoke >30 cigarettes per day (ARR:7.523; SE:7.019; accuracy 95.5%). This study also found that the risk of cancer was significantly increase with age (99% CI; ARR: 1.065; SE: 0.026). Conclusions: Cigarette smoking behaviour increased the risk any types incident of cancer. Total number >20 cigarettes smoked per day contributes to the incidence of malignant cancer.