Impact of Smoking Behavior on Survival Following Allogeneic Hematopoietic Stem Cell Transplantation - Smoking Cessation Matters

Introduction: There are only a few data on the impact of smoking and smoking cessation on the outcome of patients treated with allogeneic hematopoietic stem cell transplantation, a well-established therapy for hematologic malignancies. Methods: In a retrospective cohort study design we examined the impact of smoking and smoking cessation on survival among 309 eligible consecutive adults who underwent allogeneic hematopoietic stem cell transplantation using reduced-intensity (n = 179) or myeloablative (n = 130) conditioning between 1999 and 2018. Results: Smoking and was independently associated with increased mortality with a five-year overall survival of 25% in current smokers versus 53% in never smokers versus 48% in past smokers. Never smokers lived significantly longer (HR: 2.00, 95%CI: 1.19-3.35, p = .008) and had a better event-free survival (HR: 2.11, 95%CI: 1.27-3.49, p = .004) than current smokers. In the long run, never smokers also lived significantly longer than past smokers (HR: 1.45, 95%CI: 1.16-1.81, p = .001). Patients who quit smoking before allogeneic hematopoietic stem cell transplantation showed a tendency towards increased survival compared to those who continued smoking (HR: 1.53, 95%CI: 0.95-2.45, p = .078). In relation to life-time cigarette dose smokers with low-dose (1-10 pack-years) cigarette consumption lived significantly longer (HR: 1.60, 95%CI: 1.03-2.50, p= .037) and had a better event-free survival (HR: 1.66, 95%CI: 1.07-2.58, p= .025) than patients with high-dose (>= 10 pack-years) cigarette consumption. Conclusions: In allogeneic hematopoietic stem cell transplantation for hematologic malignancies, smoking history per se, lifetime cigarette dose, and continued smoking, were significantly associated with increased all-cause mortality and reduced event-free survival.

Automated summary

This study shows that smoking history, lifetime cigarette dose, and continued smoking are significantly associated with increased all-cause mortality and reduced event-free survival in patients undergoing allogeneic hematopoietic stem cell transplantation for hematologic malignancies. Different smoking statuses and doses have a significant impact on patient outcomes.