The Effect of Preoperative Smoking Cessation or Preoperative Pulmonary Rehabilitation on Outcomes After Lung Cancer Surgery: A Systematic Review

Abstract

The preferred treatment for lung cancer is surgery if the disease is considered resectable and the patient is considered surgically fit. Preoperative smoking cessation and/or preoperative pulmonary rehabilitation might improve postoperative outcomes after lung cancer surgery. The objectives of this systematic review were to determine the effectiveness of (1) preoperative smoking cessation and (2) preoperative pulmonary rehabilitation on peri- and postoperative outcomes in patients who undergo resection for lung cancer. We searched MEDLINE, PreMedline, Embase, Cochrane Library, Cinahl, BNI, Psychinfo, Amed, Web of Science (SCI and SSCI), and Biomed Central. Original studies published in English investigating the effect of preoperative smoking cessation or preoperative pulmonary rehabilitation on operative and longer-term outcomes in ≥ 50 patients who received surgery with curative intent for lung cancer were included. Of the 7 included studies that examined the effect of preoperative smoking cessation (n = 6) and preoperative pulmonary rehabilitation (n = 1) on outcomes after lung cancer surgery, none were randomized controlled trials and only 1 was prospective. The studies used different smoking classifications, the baseline characteristics differed between the study groups in some of the studies, and most had small sample sizes. No formal data synthesis was therefore possible. The included studies were marked by methodological limitations. On the basis of the reported bodies of evidence, it is not possible to make any firm conclusions about the effect of preoperative smoking cessation or of preoperative pulmonary rehabilitation on operative outcomes in patients undergoing surgery for lung cancer.

Introduction

Lung cancer is a disease with a notoriously low overall survival rate because patients often present with locally-advanced or distant disease and the effectiveness of the available treatments is less than optimal. Treatment of choice for stage I and II lung cancer is resection in surgically fit patients, and gives them the only realistic chance of a cure. Long-term survival in these patients can be well over 70% in some series1, 2, 3, 4 and it is important to ensure that as many patients as possible have a chance of having their cancer removed.

The focus of this report is to examine the effectiveness of different interventions in improving outcomes during and after surgical resection of lung cancer. Specifically, we report here 2 systematic reviews of the effect of preoperative smoking cessation and of preoperative pulmonary rehabilitation, respectively, on postoperative outcomes of lung cancer surgery.

Most patients presenting for lung cancer surgery are either current smokers or have a history of smoking. In addition to the long-term adverse effect of smoking on survival, smoking or a history of smoking might also negatively influence the success of pulmonary surgery because of an increased rate of peri- or postoperative pulmonary complications (eg, references 5, 6, 7, 8; but see reference ⁹) which might be linked to frequently occurring consequences of smoking such as increased sputum production, reduced forced expiratory volume in the first second of expiration (FEV₁), chronic bronchitis, or chronic obstructive pulmonary disease (COPD). However, before any recommendations can be made about delaying lung cancer treatment by resection in smokers to allow smoking cessation to take place, there would need to be good evidence that smoking cessation during the delay results in improved outcomes.

Ideally, this evidence would come from well-conducted randomized controlled trials (RCTs) comparing randomly selected groups of patients who have ceased smoking within set preoperative time periods to (1) randomly selected patients who did not cease smoking before resection to examine the effect of preoperative smoking cessation on lung cancer surgical outcomes, and to (2) each other to examine whether time elapsed between smoking cessation and resection influences the peri- or postoperative outcomes. It is, however, unlikely that such studies would be conducted as all the emphasis is on rapid access to treatment and patients are likely to be reluctant to accept delays. It is therefore necessary to systematically examine the results of studies of less ideal designs in order to achieve an indication of the effect of preoperative smoking cessation on outcomes after lung cancer surgery and that way evaluate whether further prospective research in this area is warranted.

Lung function in patients presenting for lung cancer surgery is often reduced preoperatively (eg, because of smoking) and is certainly reduced postoperatively by virtue of the intervention itself. Reduced lung function is associated with a number of complications including death. It is therefore a requirement for surgical candidates that they have adequate lung function preoperatively which is also not predicted to be unsustainably reduced postoperatively. Full or as full as possible preoperative lung function would therefore seem optimal in lung cancer surgical candidates.

Pulmonary rehabilitation constitutes an intervention that serves to restore a patient's lung function to the fullest potential possible. Thus, pulmonary rehabilitation before lung cancer surgery is potentially an attractive technique for optimizing preoperative lung function and conceivably, in turn, reducing postoperative respiratory complications.

In practice, it is often the patients with the lowest pulmonary reserve who are selected for pulmonary rehabilitation. It is, however, not unlikely that a wider spread of lung cancer surgery candidates would benefit from preoperative pulmonary rehabilitation in terms of improved short- and long-term surgical outcomes.

As was the case for the evidence relating to the effect of preoperative smoking cessation on peri- and postoperative outcomes, the ideal evidence for (or against) preoperative pulmonary rehabilitation would come from well-conducted RCTs, in this case, comparing the outcomes after lung cancer surgery between randomly selected groups of patients who have either received preoperative pulmonary rehabilitation or who have not received this preoperative intervention. However, similarly to the case of preoperative smoking cessation, it is unlikely that such studies would be conducted for the same reason, namely the introduction of a potentially unacceptable delay. It will therefore be necessary to systematically examine studies that have either provided preoperative pulmonary rehabilitation in the time period that comprises the natural work-up of a patient for surgery or studies of less controlled designs than RCTs in order to gain an indication of the effect of preoperative pulmonary rehabilitation on outcomes after lung cancer surgery.

The objectives of this study were (1) to systematically examine the effect of preoperative smoking cessation on peri- and postoperative outcomes in patients who undergo resection for lung cancer, and (2) to systematically examine the effect of preoperative pulmonary rehabilitation on peri- and postoperative outcomes in patients who undergo resection for lung cancer.