Sharp Linda, McDevitt Joseph, Brown Christopher, Carsin Anne-Elie, Comber Harry
Institute of Health & Society, Newcastle University, Newcastle upon Tyne, United Kingdom.
National Cancer Registry Ireland, Cork, Ireland.
Cancer. 2017 Jul 1;123(13):2543-2550. doi: 10.1002/cncr.30583. Epub 2017 Mar 15.
Currently, the 5-year survival rate for rectal cancer remains at <60%. The identification of potentially modifiable prognostic factors would be of considerable public health importance. A few studies have suggested associations between smoking and survival in rectal cancer; however, the evidence is inconsistent, and most of these studies were relatively small. In a large population-based cohort study, we investigated whether smoking at diagnosis is an independent prognostic factor for cancer-specific survival in rectal cancer and whether the association varies by sex, age, or treatment.
Rectal cancers (ICD10 C19-20) diagnosed between 1994 and 2012 were abstracted from the National Cancer Registry Ireland and classified by smoking status at diagnosis. Follow-up was for 5 years or until December 31, 2012. Multivariable Cox proportional hazards models were used to compare cancer-specific death rates in current smokers, ex-smokers, and never smokers. Subgroup analyses by age at diagnosis, sex, and treatment were conducted.
A total of 10,794 rectal cancers were diagnosed. At diagnosis, 25% were current smokers, 24% were ex-smokers, and 51% were never smokers. Compared with never smokers, current smokers had a significantly greater rate of death from cancer (multivariable hazard ratio [HR], 1.15; 95% confidence interval [CI], 1.06-1.24), but ex-smokers did not (HR, 1.02; 95% CI, 0.94-1.11). The association was slightly stronger in men (current versus never smokers: HR = 1.13, 95% CI, 1.02-1.24) than females (HR, 1.05; 95% CI, 0.90-1.23), but the test for interaction was not significant (P = .75). The effect of smoking was not modified by age or receipt of tumor-directed surgery, radiotherapy, or chemotherapy.
Rectal cancer patients who smoke at diagnosis have a statistically significant increased cancer death rate. Elucidation of the underlying mechanisms is urgently required. Cancer 2017;123:2543-50. © 2017 American Cancer Society.
目前，直肠癌的5年生存率仍低于60%。识别潜在可改变的预后因素具有重大的公共卫生意义。一些研究表明吸烟与直肠癌生存率之间存在关联；然而，证据并不一致，且这些研究大多规模相对较小。在一项基于大人群的队列研究中，我们调查了诊断时吸烟是否是直肠癌癌症特异性生存的独立预后因素，以及这种关联是否因性别、年龄或治疗方式而异。
从爱尔兰国家癌症登记处提取1994年至2012年期间诊断的直肠癌（ICD10 C19 - 20），并根据诊断时的吸烟状况进行分类。随访时间为5年或至2012年12月31日。使用多变量Cox比例风险模型比较当前吸烟者、既往吸烟者和从不吸烟者的癌症特异性死亡率。对诊断时的年龄、性别和治疗方式进行亚组分析。
共诊断出10794例直肠癌。诊断时，25%为当前吸烟者，24%为既往吸烟者，51%为从不吸烟者。与从不吸烟者相比，当前吸烟者的癌症死亡率显著更高（多变量风险比[HR]，1.15；95%置信区间[CI]，1.06 - 1.24），但既往吸烟者并非如此（HR，1.02；95% CI，0.94 - 1.11）。男性中的关联（当前吸烟者与从不吸烟者：HR = 1.13，95% CI，1.02 - 1.24）略强于女性（HR，1.05；95% CI，0.90 - 1.23），但交互作用检验无显著性（P = 0.75）。吸烟的影响不受年龄或是否接受肿瘤定向手术、放疗或化疗的影响。
诊断时吸烟的直肠癌患者癌症死亡率在统计学上显著增加。迫切需要阐明其潜在机制。《癌症》2017年；123：2543 - 50。© 2017美国癌症协会。
