Smoking cessation care can translate to lower hazard of death in the short-run in cancer patients - a retrospective cohort study to demonstrate the value of smoking cessation services within the treatment phase of cancer

Abstract

Background: Smoking cessation is a key step towards improving cancer care and outcomes. However, smoking cessation interventions are underprovided in oncology settings. Within Jordan's only comprehensive oncology center, we sought to evaluate receipt of care at a smoking cessation clinic and the effect of assisted abstinence through the smoking cessation clinic on short-term (two-year) survival after a cancer diagnosis.

Methods: We employed a retrospective cohort study design. Cancer registry and smoking cessation clinic data for adult Jordanian cancer patients diagnosed between 2009 and 2016, who also were cigarette smokers, and who received full treatment at King Hussein Cancer Center, were analyzed. Specifically, descriptive statistics of patients who visited the smoking cessation clinic were generated, and short-term (two-year) hazard of death of patients based on whether or not smoking cessation clinic-assisted abstinence occurred, were evaluated.

Results: There were 3403 patients who met our inclusion criteria. Approximately 21% of cancer patients were seen at the smoking cessation clinic, and significant demographic and clinical disparities in who was being seen [at the smoking cessation clinic] existed. In 2387 patients with available survival data, smokers who never went to the smoking cessation clinic (or were seen only once, or seen a year or more from diagnosis) had a hazard of death 2.8 times higher than smokers who had visited the smoking cessation clinic and who also confirmed they had not smoked on atleast two of their 3-, 6- or 12-month follow-up visits (95% confidence interval [CI] = 1.7-4.6). Non-abstainers at the smoking cessation clinic exhibited a similar disadvantage (HR 2.7, 95% CI 1.4-5.0).

Conclusions: Although evidence-based smoking cessation interventions increase the likelihood of abstinence and can lower the short-term hazard of death during cancer treatment, there is a deprioritization of smoking cessation interventions during cancer care, as indicated by low proportions of patients seen at the smoking cessation clinic. Our findings emphasize the importance of promoting interventions to avail smoking cessation interventions in oncology settings within the cancer treatment phase.

Keywords: Cancer care; Mortality; Smoking cessation intervention; Survival; Treatment.

Fig. 1

Survival curves for a subsample of cancer patients with survival data (N = 2387) divided as follows: smokers who were seen [within a year of diagnosis] more than once at the clinic and whose records indicated abstinence at atleast two follow-up points (group A); smokers who were seen [within a year of diagnosis] more than once at the clinic and whose records indicated abstinence at only one follow-up point (group B); smokers who were seen [within a year of diagnosis] more than once at the clinic and whose records indicated no abstinence at any follow-up point. Patients who did not accrue sufficient follow-up records to measure abstinence also were included in this group (group C); and smokers who were never seen at the clinic or were seen after a year from diagnosis (group D)