A snapshot of smokers after lung and colorectal cancer diagnosis

Authors

  • Elyse R. Park PhD, MPH,

    Corresponding author
    1. Mongan Institute for Health Policy, Massachusetts General Hospital, Boston, Massachusetts
    2. Tobacco Research and Treatment Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
    3. Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts
    • Massachusetts General Hospital, 50 Staniford Street, Suite 901, Boston, MA 02114

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    • Fax: (617) 724-4738

  • Sandra J. Japuntich PhD,

    1. Mongan Institute for Health Policy, Massachusetts General Hospital, Boston, Massachusetts
    2. Tobacco Research and Treatment Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
    3. Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts
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  • Nancy A. Rigotti MD,

    1. Mongan Institute for Health Policy, Massachusetts General Hospital, Boston, Massachusetts
    2. Tobacco Research and Treatment Center, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts
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  • Lara Traeger PhD,

    1. Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School, Boston, Massachusetts
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  • Yulei He PhD,

    1. Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts
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  • Robert B. Wallace MD,

    1. Department of Epidemiology, The University of Iowa, Iowa City, Iowa
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  • Jennifer L. Malin MD,

    1. David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California
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  • Jennifer P. Zallen BA,

    1. Mongan Institute for Health Policy, Massachusetts General Hospital, Boston, Massachusetts
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  • Nancy L. Keating MD, MPH

    1. Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts
    2. Division of General Medicine, Brigham and Women's Hospital, Boston, Massachusetts
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  • See editorial on pages 3012–13, this issue.

Abstract

BACKGROUND:

Continued smoking after a cancer diagnosis may adversely affect treatment effectiveness, subsequent cancer risk, and survival. The prevalence of continued smoking after cancer diagnosis is understudied.

METHODS:

In the multi-regional Cancer Care Outcomes Research and Surveillance cohort (lung cancer [N = 2456], colorectal cancer [N = 3063]), the authors examined smoking rates at diagnosis and 5 months after diagnosis and also study factors associated with continued smoking.

RESULTS:

Overall, 90.2% of patients with lung cancer and 54.8% of patients with colorectal cancer reported ever smoking. At diagnosis, 38.7% of patients with lung cancer and 13.7% of patients with colorectal cancer were smoking; whereas, 5 months after diagnosis, 14.2% of patients with lung cancer and 9.0% of patients with colorectal cancer were smoking. Factors that were associated independently with continued smoking among patients with nonmetastatic lung cancer were coverage by Medicare, other public/unspecified insurance, not receiving chemotherapy, not undergoing surgery, prior cardiovascular disease, lower body mass index, lower emotional support, and higher daily ever-smoking rates (all P < .05). Factors that were associated independently with continued smoking among patients with nonmetastatic colorectal cancer were male sex, high school education, being uninsured, not undergoing surgery, and higher daily ever-smoking rates (all P < .05).

CONCLUSIONS:

After diagnosis, a substantial minority of patients with lung and colorectal cancers continued smoking. Patients with lung cancer had higher rates of smoking at diagnosis and after diagnosis; whereas patients with colorectal cancer were less likely to quit smoking after diagnosis. Factors that were associated with continued smoking differed between lung and colorectal cancer patients. Future smoking-cessation efforts should examine differences by cancer type, particularly when comparing cancers for which smoking is a well established risk factor versus cancers for which it is not. Cancer 2012;118: 3153–64. © 2012 American Cancer Society.

INTRODUCTION

Smoking accounts for at least 30% of all cancer deaths.1 Lung cancer is the leading cause of cancer death for both men and women, with 219,000 new cases per year1; colorectal cancer is the third most common cancer in both men and women, with over 146,000 new cases per year.1 There is a clear association between tobacco use and lung cancer incidence; tobacco use is responsible for 87% of lung cancers. Studies suggest that smoking also is associated with the formation and recurrence of colorectal adenomatous polyps2 and with increased colorectal cancer incidence and mortality,3-6 although the smoking-attributable risk for colorectal cancer has not been definitively established.1

Recent estimates of smoking at lung cancer diagnosis are 20% to 30%,7-9 and estimates of smoking at colorectal cancer diagnosis are 10% to 20%.2, 4, 10-12 Research suggests that quitting smoking upon lung cancer diagnosis can improve chances for treatment efficacy, reduce chances of secondary tumors, and may double chances of survival.13-18 To our knowledge, there have been no studies examining the effects of continued smoking on treatment efficacy in patients with colorectal cancer. Although lung cancer survival rates historically have been quite low, this is likely to change if current and former smokers increasingly undergo computed tomography screening, which preliminary results of the National Lung Screening Trial19 suggest can decrease lung cancer mortality. For patients with lung cancer, as they are diagnosed at earlier, more curable stages, tobacco treatment will be even more relevant and critical. The 5-year relative survival rate for patients with colorectal cancer is 66%20; thus, there is a significant majority of cancer survivors that will need tobacco treatment to prevent future smoking-related illness and new cancers. At diagnosis, the vast majority of cancer patients report that they want to quit smoking21-23; estimates of quitting range from 35% to 79%,22-25 and approximately half of those who quit relapse within 1 year.13

Previous work examining smoking rates among cancer patients, and associated factors, have been limited by single-site, cross-sectional studies with small samples or studies conducted within the context of a clinical trial. Population-based estimates of smoking at lung cancer and colorectal cancer diagnosis are needed to understand the extent and nature of the problem. In addition, it is uncertain which factors are associated with continued smoking and, thus, should be targeted for identification and intervention.26 In this article, we examine the factors associated with continued smoking among patients with early stage disease, because the stakes differ between such patients and patients with advanced stage; therefore, clinicians may manage smoking differently. To our knowledge, this is the first large-scale, population-based study to examine the smoking behaviors of patients with lung cancer and colorectal cancer at the time of diagnosis and during follow-up. Our objective was to assess the rates of continued smoking after diagnosis and associated factors among patients with a cancer for which smoking is a strong risk factor versus cancers for which the smoking-attributable risk is unclear.

MATERIALS AND METHODS

Study Design

This study is part of a large, multi-regional, prospective study examining processes and outcomes of care for a population-based and health system-based cohort of cancer patients conducted by the Cancer Care Outcomes Research and Surveillance (CanCORS) Consortium.27 The cohort includes more than 10,000 patients who were diagnosed with lung cancer or colorectal cancer during 2003 to 2005. Details on study design and procedures have been published previously.28, 29 The study was approved by the human subjects committees at all participating institutions.

Cohort Selection

Patients aged ≥21 years who were diagnosed with lung cancer or colorectal cancer were identified within weeks of their diagnosis and were surveyed by telephone approximately 5 months after diagnosis. This analysis included only CanCORS participants who personally completed a full patient survey at baseline (N = 5519) (vs having the baseline survey completed by a surrogate if they were too ill or if they died; those survey versions did not include detailed questions about smoking status). We further limited analyses to the 5388 patients for whom information on smoking status was available.

Data Collection and Measures

Surveys were conducted using computer-assisted telephone interviews in English, Spanish, and Chinese. The response rate30 was 51%, and the cooperation rate was 60%; comparisons of responders and nonresponders have been described previously.31 It has been established that participants in CanCORS are demographically similar to population-based samples with these cancers in Surveillance, Epidemiology, and End Results registries.32 Information about cancer site, histology, and disease stage at diagnosis was obtained from registry data and medical records.

Smoking status

Smoking around the time of diagnosis was determined based on 3 questions from the baseline survey (Fig. 1). Participants were considered current smokers around the time of diagnosis if they answered “yes” to the question, “Do you smoke cigarettes regularly now?” or if they answered “yes” to the question, “Have you ever smoked cigarettes regularly?”, “no” to the question, “Do you smoke cigarettes regularly now?” and if they answered the question, “How old were you the last time you were smoking regularly?” with an age that was within 1 year of their age at diagnosis. Participants were considered former smokers around the time of diagnosis if they answered “yes” to the question, “Have you ever smoked cigarettes regularly?”, “no” to the question, “Do you smoke cigarettes regularly now?” and answered the question, “How old were you the last time you were smoking regularly?” with an age that was >1 year older than their age at diagnosis. Participants were considered current smokers at 5 months postdiagnosis if they answered “yes” to the question, “Do you smoke cigarettes regularly now?”

Figure 1.

This chart illustrates the imputation of smoking status at diagnosis and 5 months after diagnosis. Y indicates yes; N, no.

Sociodemographics

Sociodemographic variables that were included in the current analyses included sex, race, education, marital status, self-reported insurance, and age.

Cancer

Cancer stage was dichotomized as stage IV versus stages I through III. Cancer treatment included surgery, chemotherapy, and radiation treatments based on patients' reports. Cancer symptoms were assessed using the European Organization for Treatment Research of Cancer Quality-of-Life Questionnaire (EORTC QLQ)33 for lung cancer and colorectal cancer, which was scored on a 4-point Likert scale from “not at all” to “quite a bit.” The items on the EORTC QLQ were then converted to a scale from 1 to 100 in the scoring procedure.

Medical comorbidities

Patients reported on their history of cardiovascular disease, lung disease, and diabetes. We examined pain by using the Brief Pain Inventory34 worst pain item, which asks patients to rate their worst pain in the past 4 weeks on a scale from 0 (no pain) to 10 (the worst pain you can imagine). Finally, we calculated body mass index (BMI) from participants' self-reported height and weight.

Psychosocial measures

Depression was measured using an 8-item version of the Center for Epidemiological Studies Depression Scale to assess the presence or absence of symptoms over the past week.35 Fatalism was assessed using a 4-item version of the Powe Fatalism Inventory36 in which patients rated their views about health and life on a 4-point Likert scale. Health status was reported using a single item from the Short Form Health Survey as excellent, very good, good, fair, or poor.37 Emotional support was measured using the 5-item Emotional/Informational Support scale from the Medical Outcomes Study Social Support Survey38 in which items are rated on a 5-point Likert scale from 1 (all of the time) to 5 (none of the time). Physician communication was measured using 5 items from the Hospital Consumer Assessment of Healthcare Providers and Systems39 on a 4-point Likert scale from 1 (always) to 4 (never).

Health behaviors

Reported frequency of alcohol use in the year before diagnosis was categorized into heavy drinkers (≥4 days/week), social drinkers (1-3 days/week), and light/never drinkers (≤1 day/month). Finally, participants were asked to indicate their highest number of cigarettes smoked per day.

Analyses

Item nonresponse was infrequent, and we used multiple imputations to impute missing data for items other than the smoking items when conducting inferential statistics.40, 41 All data analyses were conducted using Predictive Analytic Software (version 18.0; formally Statistical Package for the Social Sciences; SPSS Inc., Chicago, Ill). By using chi-square tests and one-way analyses of variance, we compared sociodemographics, medical histories, smoking histories, psychosocial and health behavior variables between patients with lung cancer and patients with colorectal cancer. Two-sided P values < .05 were considered statistically significant.

Then, we selected participants with early stage disease (cancer stages I-III; those with unknown stage were not included in this analysis) who were smoking around the time of cancer diagnosis and assessed the factors associated with continued smoking by conducting a series of univariate logistic regression equations using sociodemographic, medical history, psychosocial, and health behavior variables. To qualify for each multivariable model, variables had to be associated with continued smoking in the univariate regression analyses (P < .25).42 All univariate and multivariate regression analyses were controlled for study site.

RESULTS

Baseline Characteristics

Patients who had lung cancer were more likely than patients who had colorectal cancer to be female, white, older, less educated, and publicly insured (Table 1). Those with lung cancer also were more likely to have a history of cardiovascular and lung disease and to have more advanced cancer, and they were less likely to have undergone surgery. Patients with lung cancer had higher ratings of depression, poorer perceived health, lower ratings of perceived emotional support, and higher numbers of cigarettes smoked per day than patients with colorectal cancer.

Table 1. Characteristics of Patients With Lung and Colorectal Cancer at 5-Months Postdiagnosis (Baseline Survey)
 Full Sample, % Smokers Around the Time of Diagnosis, % 
VariableLung Cancer (N=2456)Colorectal Cancer (N=3063)PaLung Cancer (N=925)Colorectal Cancer (N=411)Pa
  • Abbreviations: BMI, body mass index; CES-D, Center for Epidemiological Studies Depression Scale; EORTC QLQ, European Organization for Treatment and Research of Cancer Quality-of-Life Questionnaire; HCAHPS, Hospital Consumer Assessment of Healthcare Providers and Systems; MOSSSS, Medical Outcomes Study Social Support Survey; SD, standard deviation; SF-36, Short Form Health Survey.

  • a

    P values are from a comparison between patients with lung cancer and patients with colorectal cancer.

  • b

    Symptoms are specific to cancer type.

  • c

    Scores on the EORTC QOL range from 0 (no symptoms) to 100 (all symptoms experienced “quite a bit”).

  • d

    Scores on the Brief Pain Inventory range from 0 (no pain) to 10 (worst pain you can imagine).

  • e

    Scores on the CES-D range from 0 (no depression items endorsed) to 8 (all depression items endorsed).

  • f

    Scores on the Powe Fatalism Scale range from 1 (strongly disagree) to 4 (strongly agree).

  • g

    Scores on the SF-36 range from 1 (poor health) to 5 (excellent health).

  • h

    Scores on the MOSSSS range from 1 (none of the time) to 5 (all of the time).

  • i

    Scores on the HCAHPS range from 0 (worst care) to 100 (best care).

  • j

    Among those smoking at baseline.

Demographics      
 Men51.854.4.0551.560.6.002
 Race  <.001  .001
  White74.165.4 73.967.6 
  Black11.814.6 14.219.2 
  Latino4.78.6 3.94.9 
  Asian3.35.6 1.63.9 
  >1 Race3.32.8 4.21.9 
  Other52.7 2.12.4 
 Education  <.001  .17
  <High school2825.6 30.826.8 
  High school51.546.2 54.353.7 
  Some college/college20.528.2 14.919.5 
 Married/has domestic partner59.763.5.00454.653.03
 Insurance  .002  <.001
  Private69.970.9 62.953.7 
  Medicaid2.22.6 3.86.6 
  Medicare17.216.1 17.218 
  Other public53.7 7.78.5 
  Insurance not specified43.7 5.96.6 
  No insurance1.63 2.56.6 
 Median age [interquartile range], y66 [58-74]63 [53-73]<.00162 [56-69]58 [52-67]<.001
Cancer Characteristics      
 Stage  <.001  <.001
  I-III68.680.3 66.378.6 
  IV26.314.8 28.317.3 
  Unknown54.9 5.44.1 
 Cancer treatment      
  Surgery49.793.2<.00145.990<.001
  Chemotherapy59.653.9<.00164.561.3.26
  Radiation36.114.6<.00141.624.3<.001
 Cancer symptom scoreb (EORTC QLC)      
  Mean±SDc24.79±15.5618.29±14.3328.01±16.9623.06±15.39
Medical comorbidities      
  Cardiovascular disease23.716.6<.0012316.3.01
  Lung disease35.611.5<.00140.818<.001
  Diabetes14.819.8<.00113.114.1.06
  Brief Pain Inventory (worst pain), mean±SDd2.57±3.491.71±3.03<.0013.062.47.01
  BMI, mean±SD kg/m225.77±5.3826.88±5.38<.00124.92±5.1725.61±5.67.03
Psychosocial measures      
  CES-D score, mean±SDe4.12±1.763.78±1.74<.0014.41±1.794.19±1.88.05
  Powe Fatalism Scale score, mean±SDf2.67±0.642.65±0.66.472.73±0.632.67±.65 
  Perceived health score (SF-36 Item 1), mean±SDg3.07±3.063.44±1.05<.0013.03±1.072.80±1.11.001
  Emotional support score (MOSSSS), mean±SDh88.83±17.0990.42±15.82.034.26±0.954.33±0.89.23
  Physician communication score (HCAHPS), mean±SDi3.66±0.523.70±0.48.00188.86±17.5288.88±16.94.93
Health behaviors      
 Alcohol use frequency  .52  .001
  Never/rarely(<1/mo)67.968.9 6857.9 
  1-3 d/wk12.512.7 11.616.8 
  ≥4 d/wk19.618.4 20.425.3 
 Smoking      
  Current smokersj14.29<.0013765.9<.001
  Ever smokers7645.8 6334.1 
  Highest ever no. of cigarettes/d, mean±SD30.38±16.8624.24±16.89.0331.14±16.1226.62±14.84<.001

Smoking Rates

Overall, 90.2% of patients with lung cancer and 54.8% of patients with colorectal cancer had a history of ever smoking (Figs. 2, 3). Thirty percent of patients with lung cancer and 14% of patients with colorectal cancer reported quitting within 2 years prior to diagnosis (Fig. 2). Rates of smoking around the time of diagnosis were 38.7% for patients with lung cancer and 13.7% for patients with colorectal cancer (P < .001) (Fig. 3). By 5 months postdiagnosis, 14.2% of patients with lung cancer and 9.0% of patients with colorectal cancer (P < .001) remained smokers. Therefore, 63.0% of patients with lung cancer versus 34.3% of patients with colorectal cancer (P < .001) who had been smoking around the time of diagnosis had quit by 5 months after diagnosis. With respect to smoking rates by cancer stage, rates of smoking at the time of diagnosis were 37.4% for patients with early stage lung cancer and 41.5% for patients with stage IV lung cancer (P = .07). For patients with colorectal cancer, smoking rates at the time of diagnosis were 12.2% for patients with early stage disease and 18.4% for patients with advanced stage disease (P = .13). Smoking rates at 5 months postdiagnosis among patients with lung cancer were 11.3% for those with early stage disease and 17.5% for those with advanced stage disease (P < .001). Smoking rates at 5 months postdiagnosis for patients with colorectal cancer were 8.9% for those with early stage disease and 9.7% for patients with advanced stage disease (P = .60).

Figure 2.

The number of years quit prior to diagnosis by cancer type is illustrated.

Figure 3.

Smoking rates are illustrated over time by cancer type.

Factors Associated With Continued Smoking

Factors that were associated with continued smoking among patients with lung cancer were being unmarried; coverage by Medicare or other public unspecified insurance (vs private insurance); not undergoing surgery; having more lung cancer symptoms; having a history of cardiovascular disease or lung disease; reporting worse pain in the past month; having a lower body mass index; reporting higher levels of depression, poorer perceived health, and less emotional support; and having a greater highest reported number of cigarettes smoked per day (all P < .05) (Table 2). Significant factors that were associated with continued smoking among patients with colorectal cancer were white race/ethnicity, older age, not undergoing surgery, not receiving chemotherapy, reporting higher levels of depression, and having a greater highest reported number of cigarettes per day (all P < .05) (Table 2).

Table 2. Univariate Logistic Regression Models Assessing Factors Associated With Continued Smoking Among Early Stage Cancer Patients Who Were Smoking Around Diagnosisa
Independent VariableNot Smoking 5 Months After Diagnosis, %Smoking 5 Months After Diagnosis, %Unadjusted OR95% CIP
  • Abbreviations: BMI, body mass index; CES-D, Center for Epidemiological Studies Depression Scale; CI, confidence interval; CRC, colorectal cancer; EORTC QLQ, European Organization for Treatment and Research of Cancer Quality-of-Life Questionnaire; HCAHPS, Hospital Consumer Assessment of Healthcare Providers and Systems; LC, lung cancer; MOSSSS, Medical Outcomes Study Social Support Survey; OR, odds ratio; SD, standard deviation; SF-36, Short Form Health Survey.

  • a

    All analyses were done controlling for study site and patients with unknown disease stage were excluded (N=67).

Lung cancer cohort, N=613     
 Demographics     
  Men50.454.70.900.62-1.32.61
  Race     
   White (reference)75.774.11.00
   Black12.511.90.940.54-1.63.82
   Latino4.83.51.100.43-2.79.85
   Asian2.30.50.320.04-2.59.28
   >1 Race3.56.51.680.75-3.77.20
   Other1.43.52.690.80-9.08.11
  Education     
   <High school (reference)2.8335.71.00
   High school5453.10.910.63-1.31.61
   Some college/college17.811.20.560.30-1.04.06
  Married/has domestic partner67.742.30.480.34-0.68<.001
  Insurance     
   Private (reference)70.945.81.00
   Medicaid452.210.98-5.01.06
   Medicare15.323.92.341.43-3.85<.001
   Other public5.314.93.381.61-7.13.001
   Insurance not specified2.57.54.912.10-11.49<.001
   No insurance232.240.75-6.71.15
  Median age [interquartile range], y63 [55-68]60 [55-67]0.950.81-1.04.26
 Cancer characteristics     
  Cancer treatment     
   Surgery64.454.20.640.45-0.90.01
   Chemotherapy56.653.20.780.55-1.11.17
   Radiation40.241.80.990.70-1.41.96
  Cancer symptom score     
   EORTC QLQ, mean±SD25.26±16.0532.02±17.271.021.01-1.03<.001
 Medical comorbidities     
  Cardiovascular disease19.533.31.791.21-2.64.003
  Lung disease39.934.71.441.02-2.04.04
  Diabetes11.813.91.160.70-1.94.57
  Brief Pain Inventory score (worst pain), mean±SD2.64±3.433.50±3.901.061.02-1.12.01
  BMI, mean±SD kg/m225.42±5.2724.14±4.420.950.91-0.98.004
 Psychosocial measures     
  CES-D depression index score, mean±SD4.20±1.774.62±1.751.151.04-1.27.004
  Powe Fatalism Scale, mean±SD2.68±0.662.73±0.591.160.88-1.54.29
  Perceived health score (SF-36 Item 1)3.11±1.032.82±1.100.790.67-0.93.004
  Emotional support score (MOSSSS), mean±SD4.41±0.854.05±1.080.660.55-0.79<.001
  Physician communication score (HCAHPS), mean±SD88.82±18.0688.91±16.611.150.81-1.63.44
 Health behaviors     
  Alcohol use frequency     
   Never/rarely(<1/mo; reference)69.967.21.00
   1-3 d/wk11.810.90.950.54-1.67.87
   ≥4 d/wk18.321.91.340.86-2.07.19
  Highest ever no. of cigarettes/d, mean±SD29.03±14.8734.58±17.091.021.01-1.03.001
Colorectal Cancer cohort, N=323     
 Demographics     
  Men57.961.91.691.00-2.83.05
  Race     
   White (reference)56.372.91.00
   Black22.316.70.520.28-0.98.04
   Latino9.72.40.290.09-0.95.04
   Asian8.71.40.170.04-0.69.01
   >1 Race13.32.760.32-23.56.35
   Other23.41.700.33-8.77.53
  Education     
   <High school (reference)31.3251.00
   High school44.857.11.360.80-2.33.21
   Some college/college23.917.90.760.36-1.60.47
  Married/has domestic partner60.255.20.760.47-1.24.28
  Insurance     
   Private (reference)62.7511.00
   Medicaid3.95.72.090.61-7.08.24
   Medicare14.720.51.980.83-4.76.13
   Other public7.810.51.460.45-4.65.52
   Insurance not specified5.95.21.560.56-4.38.39
   No insurance4.97.12.610.85-7.97.09
  Median age [interquartile range], y57 [52-65]59 [53-68]1.211.06-1.37.004
 Cancer Characteristics     
  Cancer treatment     
   Surgery97.1910.270.08-0.96.04
   Chemotherapy64.1510.550.33-0.91.02
   Radiation22.323.31.050.60-1.85.86
  Cancer symptom score     
   EORTC QLQ, mean±SD23.70±13.9920.87±15.860.990.97-1.00.11
 Medical comorbidities     
  Cardiovascular disease14.6191.350.70-2.61.38
  Lung disease14.719.21.140.59-2.21.70
  Diabetes16.714.80.840.43-1.63.61
  Brief Pain Inventory score (worst pain), mean±SD2.82±3.632.15±3.410.950.89-1.01.13
  BMI, mean±SD kg/m226.68±5.9425.53±5.810.970.93-1.00.08
 Psychosocial measures     
  CES-D score, mean±SD4.47±1.904.00±1.850.860.76-0.98.02
  Powe Fatalism Scale score, mean±SD2.73±0.642.63±0.650.800.55-1.16.24
  Perceived health score (SF-36 Item 1), mean±SD3.21±1.133.28±1.081.100.89-1.37.37
  Emotional support score (MOSSSS), mean±SD4.22±0.894.39±0.901.120.87-1.45.38
  Physician communication score (HCAHPS), mean±SD86.18±20.1690.31±14.811.220.74-2.01.44
 Health behaviors     
  Alcohol use frequency     
    Never/rarely (<1/mo; reference)64.157.11.00
    1-3 d/wk13.616.71.300.64-2.61.47
    ≥4 d/wk22.326.21.390.77-2.51.27
  Highest ever no. of cigarettes/d, mean±SD21.33±11.7428.10±15.701.031.02-1.05<.001

Multivariable regression models are presented in Table 3. Factors that were associated with continued smoking among patients with lung cancer were having Medicare, other public unspecified insurance (vs private insurance); not undergoing surgery; not receiving chemotherapy; a history of cardiovascular disease; a lower body mass index; lower levels of emotional support; and a greater highest number of cigarettes ever smoked per day. Factors that were associated with continued smoking among patients with colorectal cancer were male gender, having a high school education (vs less than a high school education), not having health insurance (vs having private insurance), not undergoing surgery, and a greater highest number reported cigarettes ever smoked per day.

Table 3. Multivariate Models Predicting Continued Smoking Among Early Stage Cancer Patients Who Were Smoking Around the Time of Diagnosisa
Independent VariableAdjusted OR95% CIP
  • Abbreviations: BMI, body mass index; CES-D, Center for Epidemiological Studies Depression Scale; CI, confidence interval; CRC, colorectal cancer; EORTC QLQ, European Organization for Treatment and Research of Cancer Quality-of-Life Questionnaire; GED, general education degree; LC, lung cancer; MOSSSS, Medical Outcomes Study Social Support Survey; OR, odds ratio; SD, standard deviation; SF-36, Short Form Health Survey.

  • a

    All analyses were done controlling for study site.

Lung cancer cohort, N=613   
 Demographics   
  Men0.960.61-1.50.84
  Race   
   White (reference)1.00
   Black1.120.53-2.34.77
   Latino1.100.41-2.92.86
   Asian0.530.06-5.02.58
   >1 Race1.860.77-4.47.17
   Other1.770.47-6.57.40
  Education   
   <High school (reference)1.00
   High school graduate/GED1.060.70-1.62.78
   >High school0.610.29-1.27.19
  Married/has domestic partner0.720.47-1.09.12
  Insurance   
   Private (reference group)1.00
   Medicaid1.290.52-3.19.58
   Medicare1.831.04-3.22.03
   Other public2.781.21-6.37.02
   Insurance not specified4.881.91-12.51<0.001
   No insurance2.500.76-8.24.13
 Cancer Characteristics   
  Cancer treatment   
   Surgery0.500.32-0.78.002
   Chemotherapy0.580.37-0.93.02
  Cancer symptom score   
   EORTC QLQ1.011.00-1.03.13
 Medical comorbidities   
  Cardiovascular disease1.871.19-2.93.01
  Lung disease1.000.66-1.52.98
  Brief Pain Inventory (worst pain)1.020.96-1.08.51
  BMI0.950.91-0.99.01
 Psychosocial measures   
  CES-D0.960.84-1.09.57
  Perceived health (SF-36 Item 1)1.000.81-1.24.98
  Emotional support (MOSSSS)0.720.58-0.90.003
 Health behaviors   
  Alcohol use frequency   
   Never/rarely (<1/mo; reference)1.00
   1-3 d/wk0.800.42-1.52.50
   ≥4 d/wk1.220.74-2.01.43
   Highest ever no. of cigarettes/d1.021.00-1.03.02
Colorectal cancer cohort, N=323   
 Demographics   
  Men2.181.13-4.23.02
  Race   
   White (reference group)1.00
   Black0.620.28-1.37.23
   Latino0.210.04-1.31.06
   Asian0.260.05-1.31.10
   >1 Race5.630.61-52.11.13
   Other2.130.24-18.87.50
  Education   
   <High school (reference)1.00
   High school graduate/GED2.151.12-4.14.02
   >High school0.880.35-2.18.78
  Married/has domestic partner0.580.31-1.09.09
  Insurance   
   Private (reference)1.00
   Medicaid4.920.91-26.57.07
   Medicare2.140.91-5.04.08
   Other public2.430.57-10.34.23
   Insurance not specified2.790.66-11.88.16
   No insurance10.702.31-49.49.002
  Age1.130.96-1.34.15
 Cancer Characteristics   
  Cancer treatment   
   Surgery0.110.02-0.56.01
   Chemotherapy0.640.34-1.20.16
  Cancer symptom score   
   EORTC QLQ1.000.98-1.02.79
 Medical comorbidities   
  Brief Pain Inventory (worst pain)0.920.83-1.01.08
  BMI0.970.95-1.01.15
 Psychosocial measures   
  CES-D0.880.74-1.04.13
  Powe Fatalism Scale0.910.58-1.43.69
 Health behaviors   
  Highest ever no. of cigarettes/d1.041.01-1.06.002

DISCUSSION

Since the smoking rates and behaviors of cancer patients are not well understood, we used a population-based cohort to assess the prevalence of smoking at the time of lung cancer diagnosis or colorectal cancer diagnosis, quitting behavior around the time of diagnosis, and factors associated with continued smoking postdiagnosis. Almost all patients with lung cancer had a history of ever smoking; and, although there were considerably fewer patients, more than half of the patients with colorectal cancer reported ever smoking (higher than the general population rate of 42%).43 Rates of smoking at diagnosis were significantly higher for patients with lung cancer versus patients with colorectal cancer; approximately 1 in 3 patients with lung cancer reported smoking at diagnosis compared with 1 in 7 patients with colorectal cancer. By approximately 5 months postdiagnosis, smoking rates had dropped to approximately 1 in 7 for patients with lung cancer and 1 in 11 for patients with colorectal cancer. Although cancer rates did not differ significantly according to stage among patients with colorectal cancer or patients with lung cancer at the time of diagnosis, patients who had advanced stage lung cancer had higher rates of smoking after cancer diagnosis. This may reflect a sense from patients or providers that quitting smoking during advanced disease would not affect prognosis.

Our findings demonstrate that there is substantial quit activity before, during, and immediately following a cancer diagnosis. Patients with lung cancer were more likely than patients with colorectal cancer to quit around the time of diagnosis and after their diagnosis. Because of the widespread public knowledge that smoking causes lung cancer, it is plausible that patients with lung cancer associate their diagnosis with smoking and quit accordingly, whereas patients with colorectal cancer may not associate their diagnosis with smoking and, thus, may be less likely to change their smoking behavior as a result of their diagnosis. Another possibility is that oncology providers are more likely to talk to patients with lung cancer about quitting. The few studies that have been conducted on physician communication indicate that there is a great need to educate cancer patients about the risks of continued smoking after a cancer diagnosis and to offer assistance for cancer patients to quit.44-47 Our results suggest that future smoking-cessation efforts should examine differences by cancer type, particularly when comparing cancers for which smoking is a well established risk factor versus cancers for which it is not.

Many patients with lung and colorectal cancers quit around the time of diagnosis, resulting in a significant group of cancer patients who are relatively new former smokers vulnerable to relapse. The 2009 American Society for Clinical Oncology's Quality Oncology Practice Initiative recommends documenting cigarette smoking status by the second medical visit and recommending tobacco treatment counseling for patients who are receiving cancer treatment.48 Our findings emphasize the importance of following these recommendations and starting smoking-cessation and relapse prevention conversations when a cancer patient presents with a suspected malignancy, regardless of whether or not it is an established smoking-related cancer. This is a critical time to address tobacco treatment, because research indicates that the closer to the time of diagnosis smoking cessation treatment is delivered, the greater the likelihood of continued abstinence post-treatment.7, 22, 24, 49, 50

Patients with lung cancer and colorectal cancer had different baseline profiles as well as many different factors associated with continued smoking after diagnosis. Smoking-cessation treatment programs should have disease-specific targeted components to address the variations in risk subgroups and modifiable factors. Smoking-cessation interventions targeted to patients with lung cancer should be designed to enhance support.

There were 2 factors in the current study that were associated significantly with continued smoking in both groups: not undergoing surgery and the highest number of cigarettes ever smoked per day. Because of the negative effects of smoking on wound healing, many surgeons insist on abstinence from cigarettes before surgery. This type of aggressive intervention around smoking during other cancer treatments may reduce treatment complications and boost efficacy.7, 13-17, 51, 52 The highest number of cigarettes smoked per day may be a proxy for addiction and underscores the need for pharmacologic support to aid cancer patients to quit smoking as recommended by the 2008 US Public Health Service Treating Tobacco Use and Dependence Clinical Practice Guideline.53 However, little progress has been made to adapt these guideline recommendations to the needs of cancer patients or to implement these guidelines in the cancer care setting.9

Our findings are strengthened by the large, geographically diverse sample of cancer patients. Nevertheless, our findings must be viewed in consideration of several limitations. First, smoking status was assessed by self-report and, thus, is probably an underestimate of the smoking prevalence in this population. Recent analyses conducted by Park et al suggest that patients with lung cancer may under report their smoking rate; without biochemical validation of self-report, there is the possibility of deception.9 Second, the patient survey did not specifically ask whether patients were smoking at the time of diagnosis; therefore, we determined smoking status based on estimates of the timing of quitting. Third, patients whose surrogates completed the baseline survey were not included, because smoking questions were not asked of surrogates. These patients overall had more advanced stage disease and possibly had higher smoking rates. This resulted in a cohort of patients with lung cancer who were not necessarily representative of the population of lung cancer patients who smoke, in that there was a high proportion of patients with earlier stage disease. Finally, the small number of patients with colorectal cancer who were smokers reduced our statistical power to detect factors that may be associated with continued smoking after colorectal cancer diagnosis.

Acknowledgements

We thank Ms. Hannah Pajolek, BA, for her assistance in preparing this article.

FUNDING SOURCES

The work of the CanCORS Consortium was supported by grants from the National Cancer Institute (NCI) to the Statistical Coordinating Center (U01 CA093344) and the NCI-supported Primary Data Collection and Research Centers (U01 CA093332, U01 CA093324, U01 CA093348, U01 CA093329, U01 CA093339, U01 CA093326, CRS 02-164) and by the American Cancer Society (MSRG 005-05-CPPB to E. R. Park).

CONFLICT OF INTEREST DISCLOSURE

Dr. Rigotti has consulted for Pfizer, Free & Clear, and has served as site principal investigator for research grants from Pfizer and Nabi Biopharmaceuticals.

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