The clinical significance of smoking cessation in patients with cancer

Δημιουργηθηκε στις Σάββατο, 02 Νοεμβρίου 2013 03:26

Florou A¹, Gkiozos I², Syrigos K³
1. Respiratory Physician, Pulmonary and Critical Care Department, Athens Medical School, “Evgenidion” Hospital
2. Respiratory Physician, Oncology Unit G’PP, Athens, Medical School,“Sotiria” General  Hospital
3. Associate Professor of Clinical Oncology, Head of Oncology Unit G’PP, Athens, Medical School, “Sotiria” General Hospital

Introduction: Despite the established causal relationship between tobacco smoking and cancer many cancer patients continue to smoke after diagnosis. This partly reflects the ignorance of the beneficial effects of smoking cessation even after diagnosis.
Aim: To demonstrate the effect of continuing or quitting smoking in patients with diagnosed cancer.
Methods: This study is based on a review of medical databases (Pub Med CENTRAL, MEDLINE, Cochrane Library) of the last thirty years. All articles included in the present analysis were in English.
Results:  In patients with early stage lung cancer, continued smoking after diagnosis is associated with an increased risk of all cause mortality and decreased survival. Research has demonstrated significant difference in actuarial overall survival favoring the non-smoking group among patients with lung cancer.
In patients with oral cancer smoking cessation or reduction leads to a significant reduction in mortality at 3 and 5 years.
Patients with head and neck cancer who smoke during radiation therapy have statistically significant lower rates of response and survival than non-smoking patients. This difference is related to the length of time between quitting and treatment. There is also evidence that tobacco smoking exacerbates and prolongs radiotherapy induced complications.
Of particular importance is the evidence that continued smoking is associated with adverse effects during anticancer treatment. Smoking increases tumor progression and resistance to chemotherapy due to nicotine-induced resistance to apoptosis by modulating mitochondrial signaling. Continuing smoking is also related with inferior outcomes during treatment with novel targeted therapies such as erlotinib.
Continuing smoking in gastric and lung cancer patients is also associated with a 3.5 to 7fold increased risk of developing second primary tumors.
 Quitting smoking after lung cancer diagnosis is associated with better performance status even 12 months after diagnosis while persistent smokers have worse overall quality of life.
Persons who continued to smoke despite being diagnosed with cancer report more severe pain than never smokers and a greater interference from pain.
Conclusion: Continuing smoking after cancer diagnosis is related with reduced treatment efficacy and reduced survival, risk for more secondary malignancies and deterioration in quality of life.