Dataset Information

Causal Effects of Lifetime Smoking on Breast and Colorectal Cancer Risk: Mendelian Randomization Study.

ABSTRACT:

Background

Observational evidence has shown that smoking is a risk factor for breast and colorectal cancer. We used Mendelian randomization (MR) to examine causal associations between smoking and risks of breast and colorectal cancer.

Methods

Genome-Wide Association Study summary data were used to identify genetic variants associated with lifetime amount of smoking (n = 126 variants) and ever having smoked regularly (n = 112 variants). Using two-sample MR, we examined these variants in relation to incident breast (122,977 cases/105,974 controls) and colorectal cancer (52,775 cases/45,940 controls).

Results

In inverse-variance weighted models, a genetic predisposition to higher lifetime amount of smoking was positively associated with breast cancer risk [OR per 1-SD increment: 1.13; 95% confidence interval (CI): 1.00-1.26; P = 0.04]; although heterogeneity was observed. Similar associations were found for estrogen receptor-positive and estrogen receptor-negative tumors. Higher lifetime amount of smoking was positively associated with colorectal cancer (OR per 1-SD increment, 1.21; 95% CI, 1.04-1.40; P = 0.01), colon cancer (OR, 1.31; 95% CI, 1.11-1.55; P < 0.01), and rectal cancer (OR, 1.36; 95% CI, 1.07-1.73; P = 0.01). Ever having smoked regularly was not associated with risks of breast (OR, 1.01; 95% CI, 0.90-1.14; P = 0.85) or colorectal cancer (OR, 0.97; 95% CI, 0.86-1.10; P = 0.68).

Conclusions

These findings are consistent with prior observational evidence and support a causal role of higher lifetime smoking amount in the development of breast and colorectal cancer.

Impact

The results from this comprehensive MR analysis indicate that lifetime smoking is a causal risk factor for these common malignancies.

SUBMITTER: Dimou N

PROVIDER: S-EPMC7611442 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Causal Effects of Lifetime Smoking on Breast and Colorectal Cancer Risk: Mendelian Randomization Study.

Dimou Niki N Yarmolinsky James J Bouras Emmanouil E Tsilidis Konstantinos K KK Martin Richard M RM Lewis Sarah J SJ Gram Inger T IT Bakker Marije F MF Brenner Hermann H Figueiredo Jane C JC Fortner Renée T RT Gruber Stephen B SB van Guelpen Bethany B Hsu Li L Kaaks Rudolf R Kweon Sun-Seog SS Lin Yi Y Lindor Noralane M NM Newcomb Polly A PA Sánchez Maria-Jose MJ Severi Gianluca G Tindle Hilary A HA Tumino Rosario R Weiderpass Elisabete E Gunter Marc J MJ Murphy Neil N

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 20210302 5

<h4>Background</h4>Observational evidence has shown that smoking is a risk factor for breast and colorectal cancer. We used Mendelian randomization (MR) to examine causal associations between smoking and risks of breast and colorectal cancer.<h4>Methods</h4>Genome-Wide Association Study summary data were used to identify genetic variants associated with lifetime amount of smoking (<i>n</i> = 126 variants) and ever having smoked regularly (<i>n</i> = 112 variants). Using two-sample MR, we examine ...[more]

PMID: 33653810

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Dataset Information

Causal Effects of Lifetime Smoking on Breast and Colorectal Cancer Risk: Mendelian Randomization Study.

Background

Methods

Results

Conclusions

Impact

Publications

Causal Effects of Lifetime Smoking on Breast and Colorectal Cancer Risk: Mendelian Randomization Study.

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