TY - JOUR
T1 - Smoking and colorectal cancer
T2 - A pooled analysis of 10 population-based cohort studies in Japan
AU - Akter, Shamima
AU - Islam, Zobida
AU - Mizoue, Tetsuya
AU - Sawada, Norie
AU - Ihira, Hikaru
AU - Tsugane, Shoichiro
AU - Koyanagi, Yuriko N.
AU - Ito, Hidemi
AU - Wang, Chaochen
AU - Tamakoshi, Akiko
AU - Wada, Keiko
AU - Nagata, Chisato
AU - Tanaka, Kenta
AU - Kitamura, Yuri
AU - Utada, Mai
AU - Ozasa, Kotaro
AU - Sugawara, Yumi
AU - Tsuji, Ichiro
AU - Shimazu, Taichi
AU - Matsuo, Keitaro
AU - Naito, Mariko
AU - Tanaka, Keitaro
AU - Inoue, Manami
N1 - Funding Information:
Members of the research group are listed at the following: Manami Inoue (principal investigator); Motoki Iwasaki, Michihiro Muto, Eiko Saito, Norie Sawada, Taichi Shimazu, Shoichiro Tsugane, Taiki Yamaji, and Hadrien Charvat [until 2017]; Tetsuya Otani [until 2006]; Shizuka Sasazuki [until 2017] (National Cancer Center, Tokyo); Akiko Tamakoshi [until 2018] (Hokkaido University, Sapporo); Yumi Sugawara, Ichiro Tsuji, and Yoshikazu Nishino [until 2006]; Yoshitaka Tsubono [until 2003] (Tohoku University, Sendai); Tetsuya Mizoue (National Center for Global Health and Medicine, Tokyo); Shuhei Nomura (the University of Tokyo, Tokyo); Hidekazu Suzuki (Keio University, Tokyo); Hidemi Ito, Keitaro Matsuo, and Isao Oze (Aichi Cancer Center, Nagoya); Kenji Wakai [until 2017] (Nagoya University, Nagoya); Yingsong Lin (Aichi Medical University, Aichi); Chisato Nagata and Keiko Wada (Gifu University, Gifu); Yuri Kitamura (Osaka University, Osaka); Tomio Nakayama [until 2017] (Osaka International Cancer Institute, Osaka); Mariko Naito (Hiroshima University, Hiroshima); Kotaro Ozasa, Atsuko Sadakane, and Mai Utada (Radiation Effects Research Foundation, Hiroshima); and Keitaro Tanaka (Saga University, Saga). The Radiation Effects Research Foundation (RERF), Hiroshima and Nagasaki, Japan, is a public interest incorporated foundation funded by the Japanese Ministry of Health, Labour and Welfare (MHLW) and the US Department of Energy (DOE). This publication was supported by RERF Research Protocol A2-15. The views of the authors do not necessarily reflect those of the two governments. This study was supported by the National Cancer Center Research and Development Fund (30-A-15, 27-A-4, 24-A-3) and the Health and Labour Sciences Research Grants for the Third Term Comprehensive Control Research for Cancer (H21-3jigan-ippan-003, H18-3jigan-ippan-001, H16-3jigan-010). The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or the decision to submit the manuscript for publication.
PY - 2021/2/1
Y1 - 2021/2/1
N2 - Smoking has been consistently associated with the risk of colorectal cancer (CRC) in Western populations; however, evidence is limited and inconsistent in Asian people. To assess the association of smoking status, smoking intensity and smoking cessation with colorectal risk in the Japanese population, we performed a pooled analysis of 10 population-based cohort studies. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox's proportional hazards model and then pooled using a random-effects model. Among 363 409 participants followed up for 2 666 004 person-years, 9232 incident CRCs were identified. In men, compared with never smokers, ever smokers showed higher risk of CRC. The HRs (95% CI) were 1.19 (1.10-1.29) for CRC, 1.19 (1.09-1.30) for colon cancer, 1.28 (1.13-1.46) for distal colon cancer and 1.21 (1.07-1.36) for rectal cancer. Smoking was associated with risk of CRC in a dose-response manner. In women, compared with never smokers, ever smokers showed increased risk of distal colon cancer (1.47 [1.19-1.82]). There was no evidence of a significant gender difference in the association of smoking and CRC risk. Our results confirm that smoking is associated with an increased risk of CRC, both overall and subsites, in Japanese men and distal colon cancer in Japanese women.
AB - Smoking has been consistently associated with the risk of colorectal cancer (CRC) in Western populations; however, evidence is limited and inconsistent in Asian people. To assess the association of smoking status, smoking intensity and smoking cessation with colorectal risk in the Japanese population, we performed a pooled analysis of 10 population-based cohort studies. Study-specific hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox's proportional hazards model and then pooled using a random-effects model. Among 363 409 participants followed up for 2 666 004 person-years, 9232 incident CRCs were identified. In men, compared with never smokers, ever smokers showed higher risk of CRC. The HRs (95% CI) were 1.19 (1.10-1.29) for CRC, 1.19 (1.09-1.30) for colon cancer, 1.28 (1.13-1.46) for distal colon cancer and 1.21 (1.07-1.36) for rectal cancer. Smoking was associated with risk of CRC in a dose-response manner. In women, compared with never smokers, ever smokers showed increased risk of distal colon cancer (1.47 [1.19-1.82]). There was no evidence of a significant gender difference in the association of smoking and CRC risk. Our results confirm that smoking is associated with an increased risk of CRC, both overall and subsites, in Japanese men and distal colon cancer in Japanese women.
KW - colorectal cancer
KW - former smokers
KW - pooled analysis
KW - sites of colorectal cancer
KW - smoking
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U2 - 10.1002/ijc.33248
DO - 10.1002/ijc.33248
M3 - Article
C2 - 32761607
AN - SCOPUS:85089779234
VL - 148
SP - 654
EP - 664
JO - International journal of cancer. Journal international du cancer
JF - International journal of cancer. Journal international du cancer
SN - 0020-7136
IS - 3
ER -