Cigarette smoking, physical activity, and alcohol consumption as predictors of cancer incidence among women at high risk of breast cancer in the NSABP P-1 trial.

Abstract

BACKGROUND:

NSABP P-1 provides an opportunity to examine the association of behavioral factors with prospectively monitored cancer incidence and interactions with tamoxifen.

METHODS:

From 1992 to 1997, 13,388 women with estimated 5-year breast cancer risk greater than 1.66% or a history of lobular carcinoma in situ (87% younger than age 65; 67% postmenopausal) were randomly assigned to tamoxifen versus placebo. Invasive breast cancer, lung cancer, colon cancer, and endometrial cancer were analyzed with Cox regression. Predictors were baseline cigarette smoking, leisure-time physical activity, alcohol consumption, and established risk factors.

RESULTS:

At median 7 years follow-up, we observed 395, 66, 35, and 74 breast cancer, lung cancer, colon cancer, and endometrial cancer, respectively. Women who had smoked were at increased risk of breast cancer (P = 0.007; HR = 1.3 for 15-35 years smoking, HR = 1.6 for ≥ 35 years), lung cancer (P < 0.001; HR = 3.9 for 15-35 years, HR = 18.4 for ≥ 35 years), and colon cancer (P < 0.001; HR = 5.1 for ≥ 35 years) versus never-smokers. Low activity predicted increased breast cancer risk only among women assigned to placebo (P = 0.021 activity main effect, P = 0.013 activity-treatment interaction; HR = 1.4 for the placebo group) and endometrial cancer among all women (P = 0.026, HR = 1.7). Moderate alcohol (>0-1 drink/day) was associated with decreased risk of colon cancer (P = 0.019; HR = 0.35) versus no alcohol. There were no other significant associations between these behaviors and cancer risk.

CONCLUSION:

Among women with elevated risk of breast cancer, smoking has an even greater impact on breast cancer risk than observed in past studies in the general population.

IMPACT:

Women who smoke or are inactive should be informed of the increased risk of multiple types of cancer.

• Authors: Stephanie R Land, Qing Liu, D Lawrence Wickerham, Joseph P Costantino, Patricia A Ganz
• Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (Cancer Epidemiol Biomarkers Prev) Vol. 23 Issue 5 Pg. 823-32 (May 2014) ISSN: 1538-7755 [Electronic] United States
• PMID: 24569437 (Publication Type: Journal Article, Randomized Controlled Trial, Research Support, N.I.H., Extramural)
• Copyright: ©2014 AACR.

Chemical References

• Antineoplastic Agents, Hormonal
• Tamoxifen

Topics

• Adult
• Aged
• Alcohol Drinking (adverse effects)
• Antineoplastic Agents, Hormonal (therapeutic use)
• Breast Neoplasms (complications, drug therapy, pathology)
• Carcinoma, Lobular (epidemiology, etiology, pathology)
• Colonic Neoplasms (epidemiology, etiology, pathology)
• Endometrial Neoplasms (epidemiology, etiology, pathology)
• Female
• Follow-Up Studies
• Humans
• Incidence
• Lung Neoplasms (epidemiology, etiology, pathology)
• Middle Aged
• Motor Activity (physiology)
• Neoplasm Staging
• Prognosis
• Prospective Studies
• Risk Factors
• Smoking (adverse effects)
• Survival Rate
• Tamoxifen (therapeutic use)
• United States (epidemiology)