Surgically treated lung cancer patients: do they all smoke and would they all have been detected with lung cancer screening?

Impact of smoking status and chronic obstructive pulmonary disease on pulmonary complications post lung cancer surgery

Introduction

Smoking and chronic obstructive pulmonary disease (COPD) are associated with an increased risk of post-operative pulmonary complications (PPCs) following lung cancer resection. It remains unclear whether smoking cessation reduces this risk.

Methods

Retrospective review of a large, prospectively collected database of over 1000 consecutive resections for lung cancer in a quaternary lung cancer centre over a 23-year period.

Results

One thousand and thirteen patients underwent curative-intent lobectomy or pneumonectomy between 1995 and 2018. Three hundred and sixty-two patients (36%) were ex-smokers, 314 (31%) were current smokers and 111 (11%) were never smokers. A pre-operative diagnosis of COPD was present in 57% of current smokers, 57% of ex-smokers and 20% of never smokers. Just over 25% of patients experienced a PPC. PPCs were more frequent in current smokers compared to never smokers (27% vs 17%, p = 0.036), however, no difference was seen between current and ex-smokers (p = 0.412) or between never and ex-smokers (p = 0.113). Those with a diagnosis of COPD, independent of smoking status, had a higher frequency of both PPCs (65% vs 35%, p<0.01) and overall complications (60% vs 40%, p<0.01) as well as a longer length of hospital stay (10 vs 9 days, p<0.01).

Conclusion

Smoking and COPD are both associated with a higher rate of PPCs post lung cancer resection. COPD, independent of smoking status, is also associated with an increased overall post-operative complication rate and length of hospital stay. An emphasis on COPD treatment optimisation, rather than smoking cessation in isolation, may help improve post-operative outcomes.

Low positive predictive value of computed tomography screening for lung cancer irrespective of commonly employed definitions of target population

Screening for lung cancer (LC) by low-dose computed tomography (LDCT) has been demonstrated to reduce LC mortality in randomized clinical trials (RCTs), and its implementation is in preparation in many countries. However, definition of the target population, which was based on various combinations of age ranges and definitions of heavy smoking in the RCTs, is subject to ongoing debate. Using epidemiological data from Germany, we aimed to estimate prevalence of preclinical LC and positive predictive value (PPV) of LDCT in potential target populations defined by age and smoking history. Populations aged 50 to 69, 55 to 69, 50 to 74 and 55 to 79 years were considered in this analysis. Sex-specific prevalence of preclinical LC was estimated using LC incidence data within those age ranges and annual transition rates from preclinical to clinical LC obtained by meta-analysis. Prevalence of preclinical LC among heavy smokers (defined by various pack-year thresholds) within those age ranges was estimated by combining LC prevalence in the general population with proportions of heavy smokers and relative risks for LC among them derived from epidemiological studies. PPVs were calculated by combining these prevalences with sensitivity and specificity estimates of LDCT. Estimated prevalence of LC was 0.3% to 0.5% (men) and 0.2% to 0.3% (women) in the general population and 0.8% to 1.7% in target populations of heavy smokers. Estimates of PPV of LDCT were <20% for all definitions of target populations of heavy smokers. Refined preselection of target populations would be highly desirable to increase PPV and efficiency of LDCT screening and to reduce numbers of false-positive LDCT findings.

Patterns of survival and surgical treatment in lung cancer patients in Estonia by histologic type and stage, 1996-2016

Background: Lung cancer (LC) remains the most frequent cause of cancer death worldwide. We aimed to examine long-term trends in LC survival in Estonia by age, gender, histologic type and stage, with specific focus on surgical treatment.Material and methods: Data on all incident cases of LC diagnosed from 1996 to 2016 were obtained from the Estonian Cancer Registry. Logistic regression was used to examine receipt of surgical treatment in localized LC. Relative survival ratios (RSR) were calculated, and excess hazard ratios (EHR) of death were estimated by stage with gender, age, histology and period of diagnosis as independent variables.Results: Among the total of 16,423 cases, squamous cell carcinoma remained the most common histologic type. The odds of receiving surgical treatment in localized LC increased significantly over time and were associated with age, gender and histologic type. Overall, the age-standardized 5-year RSR improved significantly from 10% in 1996-2002 to 16% in 2010-2016 (from 8% to 15% in men and from 15% to 20% in women). Larger survival gain was seen in younger patients, for non-small cell LC subtypes, and for surgically treated patients. For localized disease, the 5-year RSR increased by more than 20 percentage units, reaching 50% in men and 69% in women. For all stages, the adjusted EHR of death was significantly associated with age, histologic type and period of diagnosis.Conclusions: We observed a substantial improvement of relative survival, with considerable variations across patient groups. After adjustment for age, gender and histology, a significant survival increase over time was seen for all stages. The considerable survival gain observed for localized LC can largely be attributed to rapidly growing proportion of surgically treated patients. Further investigation of LC management practices, particularly the use of non-surgical treatment options is warranted.