Elsevier

Lung Cancer

Volume 79, Issue 3, March 2013, Pages 262-269
Lung Cancer

Socioeconomic position and surgery for early-stage non-small-cell lung cancer: A population-based study in Denmark

https://doi.org/10.1016/j.lungcan.2012.11.023Get rights and content

Abstract

Aim

To examine possible associations between socioeconomic position and surgical treatment of patients with early-stage non-small-cell lung cancer (NSCLC).

Methods

In a register-based clinical cohort study, patients with early-stage (stages I–IIIa) NSCLC were identified in the Danish Lung Cancer Register 2001–2008 (date of diagnosis, histology, stage, and treatment), the Central Population Register (vital status), the Integrated Database for Labour Market Research (socioeconomic position), and the Danish Hospital Discharge Register (comorbidity). Logistic regression analyses were performed overall and separately for stages I, II and IIIa.

Results

Of the 5538 eligible patients with stages I–IIIa NSCLC diagnosed 2001–2008, 53% underwent surgery. Higher stage, older age, being female and diagnosis early in the study period were associated with higher odds for not receiving surgery. Low disposable income was associated with greater odds for no surgery in stage I and stage II patients as was living alone for stage I patients. Comorbidity, a short diagnostic interval and small diagnostic volume were all associated with higher odds for not undergoing surgery; but these factors did not appear to explain the association with income or living alone for early-stage NSCLC patients.

Conclusion

Early-stage NSCLC patients with low income or who live alone are less likely to undergo surgery than those with a high income or who live with a partner, even after control for possible explanatory factors. Thus, even in a health care system with free, equal access to health services, disadvantaged groups are less likely to receive surgery for lung cancer.

Introduction

Although Denmark has a tax-financed health care system [1], a social gradient in the prognosis of lung cancer patients has been observed, with lower relative survival rates of people with a lower socioeconomic position (SEP) in the first few years after diagnosis [2], [3]. These were, however, almost negligible 5 years after diagnosis [3], which may indicate that there is social inequality in relation to diagnosis and access to treatment. Analyses have also shown that SEP is associated with stage at diagnosis in patients with cancers of the lung and other sites in Denmark, insofar as cancer was diagnosed at earlier stages more often in patients with a high SEP [4], [5], [6], [7].

It might be assumed that patients with non-small-cell lung cancer (NSCLC) who receive similar treatment in a similar period will have similar outcomes [6]; however, many Danish patients with early-stage NSCLC do not undergo surgery. We hypothesized that the SEP of patients who do not receive surgical treatment is different from that the SEP of patients who do, and that any difference is mediated either by comorbid conditions or by factors related to the health system. The aim of this population-based study was to investigate the association between SEP and the probability of not receiving surgery among patients with potentially operable NSCLC (stages I–IIIa) in Denmark diagnosed between 2001 and 2008 and to analyze whether comorbidity or health system factors explain any relation.

Section snippets

Materials and methods

In the files of the Danish Lung Cancer Registry, we identified 25 672 persons born in 1920–1978 in whom lung cancer was diagnosed in 2001–2008. Of these, we could identify 25 566 persons in the files of Statistics Denmark two years before the year of lung cancer diagnosis (88 had emigrated and 18 had resided in Denmark for under two years). We excluded 19 281 persons (75%) with lung cancers other than stages I–IIIa NSCLC—NSCLC stage 0 (<1%), IIIb (12%), or IV (24%), small cell lung cancer

Socioeconomic position and lung cancer stage

The study population consisted of 5 538 persons in whom early-stage NSCLC had been diagnosed, comprising 58% with stage I, 19% with stage II, and 23% with stage IIIa (Table 1). The median age at diagnosis was 67 for men and 69 years for women (range 32–87 years). More patients with a short education were older, had lower income, lived alone, and had high CCI scores.

In all, 2917 patients underwent surgery (53%), comprising 68% of stage I, 44% of stage II and 20% of stage IIIa patients. More

Discussion

In this study of patients with early-stage, potentially operable NSCLC, those with stage I or II cancer who had a low income and lived alone were less likely to receive surgery, even after adjustment in the analysis for important confounders and potential mediators, such as comorbidity, diagnostic volume of the hospital ward and length of diagnostic period. Although the incidence of lung cancer is higher among persons of lower SEP than those with higher SEP [14], we found no association between

Conflict of interest statement

The authors declare no conflict of interest.

Funding

This study was financed by a grant from the Danish Cancer Society (grant no. SU08005) and from the Danish Medical Research Council (grant no. 271-08-0380).

References (20)

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