Characterization of Dyspnea in Veteran Lung Cancer Survivors Following Curative-Intent Therapy

Abstract

Purpose: Dyspnea is highly prevalent in lung cancer survivors following curative-intent therapy. We aimed to identify clinical predictors or determinants of dyspnea and characterize its relationship with functional exercise capacity (EC).

Methods: In an analysis of data from a cross-sectional study of lung cancer survivors at the VA San Diego Healthcare System who completed curative-intent therapy for stage I-IIIA disease ≥1 mo previously, we tested a thorough list of comorbidities, lung function, and lung cancer characteristics. We assessed dyspnea using the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Lung Cancer Module 13 (LC13) and functional EC using the 6-minute walk. We replicated results with the University of California San Diego Shortness of Breath Questionnaire.

Results: In 75 participants at a median of 12 mo since treatment completion, the mean ± SD LC13-Dyspnea score was 35.3 ± 26.2; 60% had abnormally high dyspnea. In multivariable linear regression analyses, significant clinical predictors or determinants of dyspnea were (β [95% CI]) psychiatric illness (-20.8 [-32.4 to -9.09]), heart failure with reduced ejection fraction (-15.5 [-28.0 to -2.97]), and forced expiratory volume in the first second of expiration (-0.28 [-0.49 to -0.06]). Dyspnea was an independent predictor of functional EC (-1.54 [-2.43 to -0.64]). These results were similar with the University of California San Diego Shortness of Breath Questionnaire.

Conclusion: We identified clinical predictors or determinants of dyspnea that have pathophysiological bases. Dyspnea was independently associated with functional EC. These results have implications in efforts to reduce dyspnea and improve exercise behavior and functional EC in lung cancer survivors following curative-intent therapy.

Figure 1.

Clinical predictors or determinants of dyspnea. (A) Dyspnea scores as assessed by the LC13 by (i) HFrEF; mean ± SE difference = 15.3 ± 6.91, P = .03. (Independent-samples t tests, equal variances assumed.) (ii) Anxiety/depression/PTSD; mean ± SE difference = 19.4 ± 6.30, P = .003. (Independent-samples t tests, equal variances assumed.) (iii) FEV₁ % predicted; R² values derived from univariable linear regression analyses (UVAs) as listed in Supplemental Digital Content 3, available at: http://links.lww.com/JCRP/A134. (B) Dyspnea scores as assessed by the SOBQ by (i) HFrEF; mean ± SE difference = 16.5 ± 6.69, P = .02. (Independent-samples t tests, equal variances assumed.) (ii) Anxiety/depression/PTSD; mean ± SE difference = 19.9 ± 6.10, P = .002. (Independent-samples t tests, equal variances assumed.) (iii) FEV₁ % predicted; R² values derived from UVAs as listed in Supplemental Digital Content 3, available at: http://links.lww.com/JCRP/A134. Abbreviations: FEV₁, forced expiratory volume in the first second of expiration; HFrEF, heart failure with reduced ejection fraction; LC13, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Lung Cancer Module 13; PTSD, post-traumatic stress disorder; SOBQ, University of California San Diego Shortness of Breath Questionnaire.

Figure 2.

Dyspnea is an independent predictor of functional exercise capacity (6MWD). (A) Dyspnea as assessed by the LC13. (B) Dyspnea as assessed by the SOBQ, R² values derived from univariable linear regression analyses as listed in Table 3. LC13, European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire Lung Cancer Module 13; 6MWD, 6-minute walk distance; SOBQ, University of California San Diego Shortness of Breath Questionnaire.