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. IMPLICATIONS: Continued and past smoking represent established risk factors for malignant and non-malignant diseases, however, they are also a strong risk factor for a poor outcome after allogeneic hematopoietic stem cell transplantation for hematologic diseases. Our study shows that the hazard ratio for death after such transplantation is doubled if patients continue smoking and even if they have quit smoking, their risk remains significantly elevated. This suggests that the smoking history provides important predictive factors for the outcome of allogeneic hematopoietic stem cell transplantation and that smoking cessation should be implemented in the treatment of hematologic diseases as early as possible.

Whole-Body Lung Function Test-Derived Outcome Predictors in Allogenic Stem Cell Transplantation.

Despite clinical advances, late onset pulmonary complications in adult recipients of allogenic stem cell transplantation are a major cause of morbidity and mortality. Reported incidence and risk factors in the literature vary broadly and are partly contradictory. Identification of pretransplant factors associated with major complications would be helpful to define individual treatment strategies and early initiation of preventive measures. To evaluate incidence and risk factors of late onset noninfectious pulmonary complications, with special regard to small airways disease (SAD) and bronchiolitis obliterans syndrome (BOS), indicating graft-versus-host disease, following myeloablative versus nonmyeloablative allogenic stem cell transplantation. We reviewed the clinical records and assessed the course of lung function and pulmonary complications in adults who underwent allogenic stem cell transplantation for hematological malignancies between 1999 and 2015 using nonmyeloablative (n = 179) or myeloablative (n = 130) conditioning at the Division of Hematology of the Medical University of Graz. All patients underwent body plethysmography pulmonary function test (PFT), diffusion capacity for carbon monoxide, and arterial blood gas analysis before and repeatedly after transplant. SAD was defined as maximal expiratory flow at 50% and 25% of forced vital capacity <70% predicted. Ventilatory disorders and gas transfer abnormalities were common before and after allogenic stem cell transplantation, independent of conditioning regimen. SAD was common in the nonmyeloablative (34%) and myeloablative (29%) groups. The 100-day post-transplant mortality was significantly associated with reduced pretransplant total lung capacity <80%. Mortality 100 days post-transplant was significantly associated with pretransplant SAD and a pretransplant smoking history. In this subset, a smoking history was independently associated with increased mortality, with a 5-year mortality of 45% compared with 26% in never-smokers. Pretransplant SAD was not predictive for the later development of BOS. Smoking history, pretransplant restrictive PFT, and pre-existing SAD are important risk factors for death following allogenic stem cell transplantation. However, pretransplant SAD is not a predictor of long-term complications, including BOS.