Smoking and Breast Cancer Screening in West Virginia: opportunities of intervention.
Abstract: Smoking has been increasingly identified as a risk factor for breast cancer among women. West Virginia has high rates of smoking, which can be further examined in relation to breast cancer screening and smoking related variables. This study used 2006 Behavioral Risk Factor Surveillance System (BRFSS) data to examine the relationship between smoking related variables and breast cancer screening behaviors among women in West Virginia age 40 and older. Findings showed that approximately 21.6% of women in the sample were current smokers, with a majority of these women smoking every day (82.5%). Half of the women in the study sample had made at least one past year quit attempt. Current smokers were less likely to have had breast cancer screening in the past one or two years, and among these women who smoke, every day smokers were less likely to obtain breast cancer screening. Smokers who did not make a quit attempt during the past year were also significantly less likely to have had mammography screening. Study results highlight an unmet need and opportunity for intervention related to breast cancer screening among women who smoke, and especially those with higher smoking intensity. Smoking status and smoking intensity should be recognized as predictors of women who are less likely to obtain breast cancer screening. These women can be identified and targeted as an important high risk population with unmet need for smoking cessation and breast cancer screening interventions.
Subject: Breast cancer (Risk factors)
Breast cancer (Diagnosis)
Breast cancer (Demographic aspects)
Smoking (Health aspects)
Smoking cessation programs (Health aspects)
Cancer (Diagnosis)
Cancer (Methods)
Authors: Tworek, Cindy
Nadpara, Pramit
Adkins, Bruce
Horn, Kimberly
Dino, Geri
Christy, Dan
Madhavan, S. Suresh
Pub Date: 10/01/2009
Publication: Name: West Virginia Medical Journal Publisher: West Virginia State Medical Association Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2009 West Virginia State Medical Association ISSN: 0043-3284
Issue: Date: Oct, 2009 Source Volume: 105 Source Issue: S1
Product: Product Code: 8000142 Antismoking Programs NAICS Code: 62142 Outpatient Mental Health and Substance Abuse Centers
Geographic: Geographic Scope: West Virginia Geographic Code: 1U5WV West Virginia
Accession Number: 218949141
Full Text: Objectives

Smoking has been increasingly identified as a risk factor for breast cancer among women. West Virginia has high smoking rates, which can be further examined in relation to breast cancer screening and smoking related variables. This study used 2006 Behavioral Risk Factor Surveillance System (BRFSS) data to examine the relationship between smoking related variables and breast cancer screening behaviors among women in West Virginia age 40 and older. Findings showed that current smokers were less likely to have had breast cancer screening in the past one or two years, and among these women who smoke, every day smokers were less likely to obtain breast cancer screening. Smokers who did not make a quit attempt during the past year were also significantly less likely to have had mammography screening. Study results highlight an unmet need and opportunity for intervention related to breast cancer screening among women who smoke, and especially those with higher smoking intensity. Smoking status and smoking intensity should be recognized as predictors of women who are less likely to obtain breast cancer screening. These women can be identified and targeted as an important high risk population with unmet need for smoking cessation and breast cancer screening interventions.

Introduction

Smoking has been identified as a behavioral risk factor associated with increased risk of breast cancer among women (1-6). While earlier studies were somewhat mixed on an association between smoking and breast cancer, recent research has suggested an increased risk using observational data and metaanalyses, including data from large prospective study designs. The California Teachers Study cohort was a large prospective study with baseline and 5-year follow-up data, which reported that current smoking was associated with increased breast cancer risk relative to non-smokers in women without family history of disease, but not among women with family breast cancer history (7-8).

Both active and passive smoking have been shown to increase breast cancer risk among women, with an increased risk among women who had ever smoked and were exposed to passive smoke (1-3). Some studies have found this risk to be especially increased during premenopausal years (2,6). In a pooled analysis of studies with thorough passive smoking exposure assessment, Johnson (2005) reported passive and active smoking to be implicated as risk factors for premenopausal breast cancer (6). Observational studies have reported moderate or strong associations between smoking and breast cancer risk and metaanalyses have reported a moderately increased summary risk in women associated with current smoking vs. never smoking. Experimental studies have also supported biological plausibility of a positive association of increased risk between smoking and breast cancer (4-5).

Smoking rates in West Virginia are the highest in the nation, with the state ranking first in adults who are current smokers (26.5%) from 2008 BRFSS data (9). National Survey on Drug Use and Health (NSDUH) data from 2004-2005 report past month smoking rates of 31.8% among West Virginia adults aged 26 and older, and West Virginia Adult Tobacco Survey data from 2005 report approximately one-fifth of adults in West Virginia are current smokers (10-11). Average aggregate county-specific smoking rates among adults in West Virginia (2001-2005) depicted by Figure 1 range from 21.0% to 40.9%, with 17 counties having smoking prevalence rates at or above 30.0% (12).

Smoking rates among adult females in West Virginia were also higher than the national average at 23.0%, and the average adult female smoker in West Virginia consumed 19 cigarettes per day (11). Smoking rates in 2005 were highest among young adult women in West Virginia and prevalence decreased with age; however, women 35-44 years had a smoking prevalence of 26.6%, women 45-54 years had a prevalence of 21.5%, and women 55 to 64 years had a prevalence of 19.9% (11).

As the second most commonly diagnosed cancer among women in the US, breast cancer is often successfully identified in early stages through screening intervention (13). Mammography screening is considered to be the gold standard for identification of early stage breast cancer, and the American Cancer Society recommends that all women [greater than or equal to] 40 years of age with an average risk of breast cancer receive annual mammography screening (13-15). Clinical breast exam by a health expert is also recommended annually for women age 40 and older as an important tool for breast cancer screening and early detection (15). Self-reported annual mammography screening rates among women in West Virginia were slightly lower than the national average at 58.1% (16).

[FIGURE 1 OMITTED]

Given high rates of smoking among women in West Virginia, recent research relating smoking to increased breast cancer risk, and the importance of mammography screening to early breast cancer detection, there is a need to further examine breast cancer screening and smoking status in West Virginia. The purpose of this study is to: 1) examine smoking status and variables related to smoking among women in West Virginia age 40 and older using 2006 Behavioral Risk Factor Surveillance System (BRFSS) data; 2) determine if breast cancer screening behaviors (mammogram, clinical breast exam) differ by smoking related variables (smoking status, smoking intensity, and past year quit attempt) among women age 40 and older in West Virginia; and 3) examine if smoking related variables are predictors of breast cancer screening behaviors among West Virginia women age 40 and older.

Methods

Data for breast cancer screening behaviors and smoking related variables were obtained from the 2006 West Virginia Behavioral Risk Factor Surveillance System (BRFSS) Survey (17). The BRFSS is a cross-sectional telephone survey of non-institutionalized adults aged 18 years or older, and is conducted by the Centers for Disease Control and Prevention and state health departments. The BRFSS questionnaire concerns personal behaviors that increase risk for 1 or more of the 10 leading causes of death in the United States (17). BRFSS uses a multistage cluster design based on random digit dialing methods to select a representative sample from each state's non-institutionalized residents and data collected from each state are pooled to produce nationally representative estimates (19-20). Additional details about the BRFSS, its design, and sampling procedures have been published elsewhere (19-20).

For these study purposes, 2006 BRFSS data from females [greater than or equal to] 40 years of age in the state of WV were included for analyses and constituted the sample of interest. The primary outcome variables were breast cancer screening behaviors of whether women had a mammogram or a clinical breast exam in the past one/ two years. Smoking related variables were smoking status (current smoker yes/no); smoking intensity (every day smokers; some day smokers); and past year quit attempt (stopped smoking in the past 12 months yes/no). Smoking related variables were included as independent predictor variables in logistic regression models. Demographic variables controlled for in analyses included age, education, income, race and health insurance status.

Data were weighted and analyzed using SAS version 9.2[R] to account for the complex sampling design (21). Weighted descriptive statistics and Wald's Chi-Square test statistics were generated using PROC SURVEYFREQ to analyze the data and test for significant differences in breast cancer screening behaviors by smoking related variables. Logistic regression analyses were also conducted to examine the relationship of smoking related variables as predictors of breast cancer screening behavior among women in the study sample. The odds ratio of having a mammogram/ clinical breast exam in the past one/two years were obtained using PROC SURVEYLOGISTIC by smoking related variables.

Results

Results for West Virginia women age 40 and older are presented from analyses using BRFSS data. Table 1 presents weighted descriptive statistics for smoking behavior variables, which are representative of the state population, and shows that 21.6% of women age 40+ in the sample are current smokers. Among these current smokers, 82.5% smoke every day and 17.5% smoke some days. Approximately half of the women in the study sample had made one quit attempt in the past year (49.9%).

Table 2 shows breast cancer screening behaviors among West Virginia women by smoking behavior variables. Smokers were less likely to be screened by mammogram or clinical breast exam in the past year or two years, and these differences were statistically significant by current smoking status. Only 47.0% of current smokers had a mammogram in the past year, while close to two-thirds of non-smokers reported having one (66.1%). Fewer smokers also reported having a clinical breast exam in the past year (54.6%) than non-smokers (66.9%). Screening behaviors differed significantly by smoking intensity. Every day smokers were significantly less likely than some day smokers to have had a mammogram in the past year or the past two years, and every day smokers were also significantly less likely to have had a clinical breast exam in the past two years than some day smokers. Past year quit attempt was not significantly associated with mammogram or clinical breast exam screening behaviors; however, the percent of women participating in screening was higher among those who reported a quit attempt during the past year.

Logistic regression analyses were conducted to examine the relationship between smoking behaviors and breast cancer screening behaviors as predictors. Table 3 shows statistically significant findings (p<0.01) that the odds of receiving a mammogram in the past year or two years were 40% lower among current smokers. Smokers who did not make a quit attempt during the past year were also significantly less likely to have had mammography screening in the past one or two years.

Discussion

Our findings highlight an unmet need and opportunity for intervention related to breast cancer screening among women who smoke, and especially those with higher smoking intensity. Smoking rates are high among West Virginia women, who would benefit from education and smoking cessation intervention. With an average smoking rate of 21.6% in our 2006 BRFSS sample of women at least 40 years of age, there is a need and an opportunity to bring cessation interventions to this population.

Prior studies have suggested an increased breast cancer risk among women who smoke; therefore, our study findings are especially relevant as they indicate that this high risk group is less likely to participate in annual and biannual breast cancer screening. It would be desirable for behavioral smoking cessation programs to include information on breast cancer screening locations and services to encourage this population to participate in annual mammograms and clinical breast exams.

Accessible breast cancer screening services provided across the state also include smoking cessation materials and contact information for the West Virginia quitline. Throughout its operation, the West Virginia quitline has sent tobacco cessation materials to thousands of women callers, and through Fiscal Year 2008 has averaged 1,150 women annually who enrolled for its services (22). Piloting a fax-to-quit program among women being screened for breast cancer could be another way to encourage quitting and self-referral to the quitline among women who smoke. Referrals could be faxed into the quitline, which would then proactively provide follow-up counseling to women who want to quit. There is a strong evidence base for providing education and reminder systems that facilitate integration of tobacco cessation services into clinical services, further engaging health providers in the quitting process (23).

A recent panel report by Canadian experts asserted that evidence from new studies strongly suggests smoking increases breast cancer risk and warned that girls and young women face special risks from exposure to tobacco smoke, particularly in stages of development (24). Statewide education and awareness needs to be further studied and addressed in terms of improving both smoking cessation and breast cancer screening intervention opportunities among women in West Virginia. This study was unique in examining the relationship between smoking behavior, as an identified risk factor for breast cancer, and breast cancer screening behaviors.

Findings suggest that smoking status and smoking intensity should be recognized as predictors of women who are less likely to be screened for breast cancer. These women should be targeted as an important high risk population subgroup with unmet need for both smoking cessation and breast cancer screening interventions.

CME Post-Test

28. T or F Smoking has been identified as a risk factor for breast cancer among women.

29. T or F Current smokers were more likely to have had breast cancer screening in the past one or two years.

30. T or F Smoking status and smoking intensity should be recognized as predictors of women who are less likely to obtain breast cancer screening.

31. T or F Study results suggest an unmet need and opportunity for intervention related to breast cancer screening among women who smoke.

References

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(18.) Remington PL, Smith MY, Williamson DF, Anda RF, Gentry EM, Hogelin CG. Design, characteristics, and usefulness of state-based behavioral risk factor surveillance: 1981-1987. Public Health Rep. 1988; 103: 366-375.

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(21.) SAS System, Version 9.2. Cary, NC: SAS Institute Inc; 2008.

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(23.) The Community Guide to Preventive Services. National Center for Health Marketing. Centers for Disease Control and Prevention. Atlanta, GA: March 2009.

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Cindy Tworek, PhD, MPH [1,2] Pramit Nadpara, MS, BPharm [1] Bruce Adkins, MS, PA [3] Kimberly Horn, EdD [3,4] Geri Dino, PhD [3,4] Dan Christy, MPA [5] S. Suresh Madhavan, MBA, PhD [1]

[1] Department of Pharmaceutical Systems and Policy, School of Pharmacy, West Virginia University, IMorgantown, WV.

[2] Translational Tobacco Reduction Research Program (T2R2), Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV.

[3] Division of Tobacco Prevention, West Virginia Bureau for Public Health, Charleston, WV.

[4] Department of Community Medicine, School of Medicine, West Virginia University, Morgantown, WV.

[5] Health Statistics Center, West Virginia Bureau for Public Health, Charleston, WV.
Table 1: Weighted Descriptive Statistics for Smoking Behavior among
Women age 40 and older in West Virginia, BRFSS 2006

                                         Weighted   Percent  S.E. of
       Variable Name          Frequency  Frequency    (%)    Percent

Smoking Status:
  Current Smoker
    Yes                          384      105671     21.6      1.1
    No                          1389      383032     78.4      1.1

Smoking Intensity:
  Current Smoker--now smokes
    every day                    314       87144     82.5      2.1
  Current Smoker--now smokes
    some days                    70        18526     17.5      2.1

Past Year Quit Attempt:
  Stopped smoking in past
    12 months
    Yes                          188       52420     49.9      2.9
    No                           194       52731     50.2      2.9

Table 2: Smoking Behavior and Breast Cancer Screening Behavior
among Women age 40 and older in West Virginia, BRFSS 2006

                                                 Wald Chi-
                                                  Square
                         Smoker     Non-Smoker   Statistic
                        (n = 384)   (n = 1389)   (p-value)
Mammogram
  Had in past year        47.0%       66.1%       < 0.001
  Had in past 2 years     61.0%       78.2%       < 0.001

Clinical Breast Exam
  Had in past year        54.6%       66.9%       < 0.002
  Had in past 2 years     70.6%       76.7%       < 0.028

                                               Wald Chi-
                        Every Day   Some Day    Square
                         Smoker      Smoker    Statistic
                        (n= 314)    (n = 70)   (p-value)
Mammogram
  Had in past year        44.3%      60.0%      < 0.036
  Had in past 2 years     58.4%      74.0%      < 0.019

Clinical Breast Exam
  Had in past year        53.3%      60.9%      < 0.294
  Had in past 2 years     68.2%      82.2%      < 0.018

                         Stopped Smoking in      Wald Chi-
                           past 12 months         Square
                           Yes         No       Statistic
                        (n = 188)   (n = 194)   (p-value)
Mammogram
  Had in past year        51.8%       41.6%      < 0.075
  Had in past 2 years     65.3%       56.4%      < 0.118

Clinical Breast Exam
  Had in past year        59.0%       49.7%      < 0.104
  Had in past 2 years     73.8%       67.2%      < 0.204

Table 3: Logistic Regression Analyzing Smoking Status and Healthy
Behavior in Women age 40 and older in West Virginia, BRFSS 2006

                                            Dependent Variable

                                                 Mammogram

                                      Had in              Had in
                                     past year         past 2 years

                                    Odds Ratio          Odds Ratio
          Variables                (95% CI) (a)        (95% CI) (a)

Current Smoker
  Yes                            0.6 (0.4-0.8) ***   0.6 (0.4-0.9) **
  No                                 Referent            Referent

Smoking Intensity
  Current Smoker--now
    smokes every day               0.6 (0.3-1.1)       0.6 (0.3-1.2)
  Current Smoker--now
    smokes some days                 Referent            Referent

Quit Attempt in past 12 months
  No                              0.6 (0.3-0.9) *     0.6 (0.3-0.9) *
  Yes                                Referent            Referent

                                            Dependent Variable

                                           Clinical Breast Exam

                                      Had in              Had in
                                     Past Year         Past 2 years

                                    Odds Ratio          Odds Ratio
          Variables                (95% CI) (a)        (95% CI) (a)

Current Smoker
  Yes                              0.8 (0.6-1.0)       0.9 (0.6-1.2)
  No                                 Referent            Referent

Smoking Intensity
  Current Smoker--now
    smokes every day               0.7 (0.4-1.4)       0.5 (0.2-1.1)
  Current Smoker--now
    smokes some days                 Referent            Referent

Quit Attempt in past 12 months
  No                               0.6 (0.4-1.0)       0.6 (0.4-1.1)
  Yes                                Referent            Referent

(a) Note: Each Odds Ratio individually controlled for Age, Education,
Income, Race & Health Coverage Status.

* p<0.05

** p<0.01

*** p<0.001
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