The effect of comorbidity on stage-specific survival in resected non-small cell lung cancer patients
Introduction
Surgical resection is the principal treatment for non-small cell lung cancer (NSCLC) patients with early stage disease, but only around 20% of patients are eligible for surgery at the time of diagnosis. Pathological tumour stage is the most powerful predictor of long-term survival, and the revised 7th edition tumour-node-metastasis (TNM) lung cancer staging system provides better prognostic value than previous versions.1 However, there remains great variation in prognosis and survival between patients with similar stage lung cancer.
A range of factors, including lung function, age, performance status and comorbidity are known to affect survival of NSCLC patients who undergo surgical resection. Patients diagnosed with lung cancer often have severe comorbidity that adversely affects overall survival. The most common comorbid conditions in lung cancer patients are age- and tobacco-related illnesses such as cardiovascular disease, chronic obstructive pulmonary disease (COPD) and other malignancies.2 There is evidence that the presence of comorbid conditions is an independent prognostic factor in patients with resected stage I NSCLC.3, 4, 5, 6, 7
Most of the available studies were conducted using the 6th edition of the TNM lung cancer staging system, which allowed for less accurate survival predictions and may have affected the relative prognostic importance of comorbidity. Moreover, most studies were small or based on a single-institution series of patients. In the present study, we investigated the effect of comorbidity on stage-specific survival in a population-based study of NSCLC patients who underwent surgical resection in Denmark between 2005 and 2010.
Section snippets
Patients
The Danish Lung Cancer Registry (DLCR) was established in 2000, and has since collected data on diagnostic procedures, staging, surgical procedures and complications, oncological treatment and survival through nationwide registration of clinical information on all lung cancer patients from the 37 hospital departments involved in the treatment of lung cancer in Denmark. Through record linkage, patient records are complemented with data from national databases: demographic information is
Results
Table 1 shows an overview of all 20,461 lung cancer patients identified in the DLCR between 2005 and 2010, according to CCS. A high CCS was more common in older patients (aged 70 and over), patients with a poor performance status (ECOG = 2 or greater), patients with a predicted FEV1 of less than 50% and among males. Patients with severe comorbidity were more likely to be treated with a wedge resection or not to undergo surgery (p < 0.001). No differences in clinical TNM stage or histological type
Discussion
In this study, we observed that comorbidity impairs survival in resected NSCLC patients, and that this effect is not confined to the peri-surgical or intermediate period. Severe comorbidity was found to affect stage-specific survival to the extent that the difference in survival is as big as an increment in stage group.
This is the first study that addresses the effect of comorbidity on survival among resected NSCLC patients in a large, unselected, population-based cohort of lung cancer
Conclusion
The results from this large, nation-wide, population-based group of NSCLC patients who had undergone surgical resection show that severe comorbidity impairs survival throughout a long period post-surgery by as much as a single stage increment. More detailed studies are required to identify characteristics of NSCLC patients with locally advanced disease and/or comorbidity who might benefit from surgical resection.
Conflict of interest statement
None of the authors have conflicts of interest to declare.
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2020, Research in Social and Administrative PharmacyCitation Excerpt :In fact, survival rates for cancer patients with severe comorbidities do not appear to have improved over time, despite advances in care.11 These findings are evident across multiple cancer types, including breast cancer, colorectal cancer, lung cancer, prostate cancer, and hematologic cancers.10,12–17 For example, a study of 62,591 women diagnosed with early breast cancer investigated the association between the Charlson Comorbidity Index (CCI, a measure of the presence and severity of comorbidities) and 5-year overall survival trends.11