Kim Hwa Jung, Lee Seung-Mi, Choi Nam-Kyong, Kim Seon Ha, Song Hong-Ji, Cho Young Kyun, Park Byung-Joo
Department of Preventive Medicine, Seoul National University College of Medicine.
J Prev Med Public Health. 2006 Mar;39(2):123-9.
The incidence of colorectal cancer increased greatly among the elderly in Korea, but the relationship between smoking and colon cancer remains controversial. Few studies have targeted Asian elderly people. We analyzed the smoking status, the amount smoked, and the smoking duration as risk factors of colorectal cancer to determine their association and causality.
The cohort members (n = 14,103) consisted of 4,694 males and 9,409 females, and they were derived from the Korea Elderly Phamacepidemilogic Cohort (KEPEC), which was a population-based dynamic cohort. They were aged 65 years or more and they lived in Busan Metropolitan City between from 1993-1998; they were beneficiaries of the Korean Medical Insurance Corporation (KMIC). The baseline information was surveyed by a self-administered mailed questionnaire; after 8.7 person-years of mean follow up period, 100 cases of colorectal cancer occurred. The adjusted relative ratio (aRR) of smoking status, the smoking amount and the smoking duration were calculated from the Cox's proportional hazard model with the never-smokers as a reference group and the Cox model controlled for age, gender, precancerous lesions of CRC, medication history of NSAIDs and antibiotics, the alcohol drinking status and BMI.
Compared with the never smokers, the aRRs were 2.03 (95% CI = 1.02-4.03) and 1.36 (95% CI = 0.80-2.32) for the ex-smokers and current smokers, respectively. Statistical significant trends were not observed for the dose-relationship among the elderly, either for the mean daily amount smoked (p for trend = 0.28) or for the total amount (p for trend = 0.15). Still, the aRRs were 1.51 (95% Cl = 0.97-2.34) for the elderly who smoked less than 40 years and 2.35 (95% CI = 1.16-4.74) for the elderly who had 40 years or more of smoking (p for trend = 0.06). Smokers who started smoking before the age 20 had an increased aRR of 2.15 (95% CI = 1.17-3.93) compared to the never smokers.
After controlling for age, gender, precancerous lesion of CRC, medication history of NSAIDs and antibiotics, the alcohol drinking status and BMI, smoking increases the risk of colorectal cancer among elderly people. The age when starting smoking is also important.
韩国老年人中结直肠癌发病率大幅上升，但吸烟与结肠癌之间的关系仍存在争议。针对亚洲老年人的研究较少。我们分析了吸烟状况、吸烟量和吸烟持续时间作为结直肠癌的危险因素，以确定它们之间的关联和因果关系。
队列成员（n = 14103）包括4694名男性和9409名女性，他们来自韩国老年人药物流行病学队列（KEPEC），这是一个基于人群的动态队列。他们年龄在65岁及以上，1993年至1998年居住在釜山广域市；他们是韩国医疗保险公社（KMIC）的受益人。基线信息通过自填邮寄问卷进行调查；在平均随访8.7人年之后，发生了100例结直肠癌病例。以从不吸烟者为参照组，从Cox比例风险模型计算吸烟状况、吸烟量和吸烟持续时间的调整相对比（aRR），Cox模型控制了年龄、性别、结直肠癌癌前病变、非甾体抗炎药和抗生素用药史、饮酒状况和体重指数。
与从不吸烟者相比，既往吸烟者和当前吸烟者的aRR分别为2.03（95%CI = 1.02 - 4.03）和1.36（95%CI = 0.80 - 2.32）。在老年人中，无论是平均每日吸烟量（趋势p = 0.28）还是吸烟总量（趋势p = 0.15），均未观察到剂量关系的统计学显著趋势。然而，吸烟少于40年的老年人的aRR为1.51（95%Cl = 0.97 - 2.34），吸烟40年或更长时间的老年人的aRR为2.35（95%CI = 1.16 - 4.74）（趋势p = 0.06）。与从不吸烟者相比，20岁之前开始吸烟的吸烟者的aRR增加了2.15（95%CI = 1.17 - 3.93）。
在控制了年龄、性别、结直肠癌癌前病变、非甾体抗炎药和抗生素用药史、饮酒状况和体重指数之后，吸烟会增加老年人患结直肠癌的风险。开始吸烟的年龄也很重要。
