Treatment Complication Rates in Ongoing Smokers Versus Quitters After a Diagnosis of Lung Cancer: A Cohort Study - European Medical Journal
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Treatment Complication Rates in Ongoing Smokers Versus Quitters After a Diagnosis of Lung Cancer: A Cohort Study

| Respiratory
EMJ Respiratory 8.1 2020 Feature Image
Authors:
*Rachel E. Gemine,1,2 Kirsty J. Lanyon,2 Gareth R. Davies,1 Keir E. Lewis1,2
Disclosure:

This research was funded by a GRAND research award from Pfizer. Dr Lewis reports grants from Pfizer, during the conduct of the study. The other authors have declared no conflicts of interest.

Acknowledgements:

The authors would like to thank all patients and recruiting sites for their participation in this study.

Citation
EMJ Respir. ;8[1]:70-71. Abstract Review No. AR4.

Each article is made available under the terms of the Creative Commons Attribution-Non Commercial 4.0 License.

BACKGROUND AND AIMS

Despite technical advances in investigations and treatment, the 5-year survival for lung cancer (LC) remains poor. Studies suggest that continued smoking after a diagnosis of LC independently worsens quality of life and shortens life expectancy; however, these were small, retrospective cohorts where smoking was usually only self-reported and only recorded at baseline. The authors have recently shown that quitting smoking following a diagnosis of non-small cell lung cancer (NSCLC) may lead to a reduction in mortality by 17% at 1 year.1

Smoking can adversely affect outcome by causing and accelerating other illnesses in people with LC. Smokers are more likely to be diagnosed with chronic obstructive pulmonary disease, heart disease, cerebrovascular disease, high blood pressure, diabetes, thrombosis, and many other conditions.2,3 Continued smoking worsens any comorbid condition, which can lead to increased risk of infections, resulting in delays or interruptions to LC treatment.

In patients with head and neck cancer, those who stopped smoking following diagnosis survived twice as long as those who continued to smoke. Those who continued to smoke had a four-times greater rate of recurrence.4 In patients with breast cancer, recurrence in smokers was 15% higher (p=0.039) compared to those who quit.5 This is further replicated in patients with prostate cancer.6

The aim of the study was to determine if quitting smoking after a diagnosis of LC reduces complication rates, including treatment interruptions and hospital admission.

MATERIALS AND METHODS

As part of a UK multicentre, prospective, observational cohort study of 1,134 patients with newly diagnosed NSCLC, the authors recorded self-reported smoking status, validated with exhaled carbon monoxide readings, at baseline and each follow-up visit until death for up to 2 years. Treatment complications were noted by free text if reported by the patient (e.g., diarrhoea, vomiting), or by the clinical team (e.g., post-operative wound infection, chemotherapy-induced neutropenia, radiation pneumonitis). They were reviewed by a study clinician blinded to smoking status but were not graded according to severity.

Smoking cessation treatments were offered according to local services. Data were recorded on study case report forms and confirmed from hospital records and cancer databases; data were analysed with Stata.

RESULTS

Of the 1,134 patients recruited, 290 (25.6%) were smokers at baseline and 84 (29%) of these quit within 3 months of diagnosis. Continued smokers (66.5 years; standard deviation: 9.4) were of similar age to quitters (66.1 years; standard deviation: 9.6; p=0.232), but 34.7% of quitters had Stage I and II NSCLC, compared to 19.2% of smokers (p<0.001). 28.6% underwent surgery compared to 8.1% in those who continued to smoke (p<0.001). At 12 months, 55.6% of quitters were deceased compared to 68.1% of continued smokers (p<0.01).

At 1 month, quitters had fewer treatment complications than those who continued to smoke (p=0.03). At 6 months (p=0.76) and 12 months (p=1.00), there were no differences in complication rates between quitters and continued smokers (Figure 1).

Figure 1: Non-small cell lung cancer treatment complication rates comparison by smoking status.

CONCLUSION

Quitting smoking after a diagnosis of NSCLC is associated with fewer treatment complications at Month 1. This may be due to the confounding effects of increased Stage I and II tumours and higher number of surgical resections in quitters. The authors have continued to follow outcomes with larger numbers, grouping treatment-related complications into ‘mild’, ‘moderate’, or ‘severe’ according to standard definitions, as well as noting whether these complications necessitated treatment delays or treatment changes.

References
Gemine RE et al. Longitudinal study to assess impact of smoking at diag-nosis and quitting on 1-year survival for people with non-small cell lung cancer. Lung Cancer. 2019;129:1-7. Centers for Disease Control and Prevention (CDC); National Center for Chronic Disease Prevention and Health Promotion; Office on Smoking and Health. How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General. 2010. Available at: https://www.ncbi.nlm.nih.gov/books/NBK53017/. Last accessed: 16 September 2020. National Health Service (NHS). What are the health risks of smoking? 2015. Available at: http://www.nhs.uk/chq/Pages/2344.aspx?CategoryID=53&SubCategoryID=53. Last accessed: 1 February 2016. Stevens MH et al. Head and neck cancer survival and life-style change. Arch Otolaryngol. 1983;109(11):746-9. Bishop JD et al. Smoking and breast cancer recurrence after breast conservation therapy. Int J Breast Cancer. 2014;2014: 327081. Daniell HW. A worse prognosis for smokers with prostate cancer. J Urol. 1995;154(1):153-7. Dr Keir Lewis. Studies Examining the Importance of Smoking After Being Diagnosed With Lung Cancer (LungCast). NCT01192256. https://clinicaltrials.gov/ct2/show/NCT01192256.