Cancer patients who continue smoking after their diagnosis experience greater intensity of pain compared with those who stop or who never started, according to the study titled Associations between pain and current smoking status among cancer patients published in the January 2011 issue of Pain.
The researchers introduced the study with some important statistics about the link between pain and smoking. They noted that approximately 58 percent of smokers diagnosed with cancer continue smoking. This behavior results in “impaired healing, reduced treatment efficacy, increased risk for developing a second primary cancer, and poorer survival.”
They also explained their interest in the association between pain level and smoking was based on several phenomena:
- Thirty- 45 percent of early stage cancer patients experience moderate to severe pain.
- About 75 percent of advanced stage cancer patients experience moderate to very severe pain.
- There is an emerging body of evidence that suggests there is an association between smoking and recurrent pain among people who don’t have cancer.
- Smokers who experience recurrent pain express a greater motivation to smoke and increase cigarette consumption. In a 2008 study, two researchers, Joseph W. Ditre and Thomas H. Brandon used these findings to explain a reciprocal relationship between pain and tobacco smoking that creates a positive feedback cycle, leading to increased pain, higher cigarette consumption, and the continuing dependence on nicotine.
Participants who took part in this study were part of a larger clinical trial investigating the effectiveness of interventions designed to improve quality of life during chemotherapy treatment, such as stress management and exercise training. The eligibility requirements to be included in the clinical trial included being over 18 years old, having a current diagnosis of cancer, not having received intravenous chemotherapy within the past 2months, and being scheduled to receive outpatient chemotherapy over a period of at least 9weeks.
In addition, they must be able to speak and read English, have no medical reason for not participating in moderate intensity exercise and graded exercise testing, and be able to walk without assistance.
At the start of the study, participants completed questionnaires regarding whether they were a current smoker and how many cigarettes they consumed. Based on this, the researchers created the following participant categories:
- Never smokers – patients who reported smoking fewer than 100 cigarettes in their lifetime.
- Smokers – patients who reported smoking more than 100 cigarettes in their lifetime.
- Former smokers – patients who reported having quit smoking and not having smoked any cigarettes in the past month.
- Current smokers – patients who reported having smoked in the past month. Current smokers were also asked about the number of cigarettes they currently smoked per day.
The researchers measure the participants’ pain level on a weekly basis using the Medical Outcomes Survey 36-item Short Form. This is a self-assessment of the severity of 32 symptoms commonly experienced by cancer patients. Participants were asked to rate their severity of bodily pain (1=“none” to 6=“very severe”) and the degree to which pain interfered with their daily routine (1=“not at all” to 5=“extremely”). They were also asked to report the level of distress associated with the pain they experienced (0=“not at all” to 4=“very much”) using the Memorial Symptom Assessment Scale-Short Form.
The scientists drew two important conclusions from this data. The first is that current smokers said they experienced a great deal more severe pain than those who never smoked, and greater interference from pain than former smokers or those who never smoked. The researchers also observed that the longer the time span since a patient had quit smoking, the less pain that patient reported.