Systematic review of the literature on the occurrence and characteristics of dyspnea in oncology patients

Potential Therapeutic Role of Respiratory Muscle Training in Dyspnea Management of Cancer Survivors: A Narrative Review

Dyspnea is a disabling symptom presented in approximately half of all cancer survivors. From a clinical perspective, despite the availability of pharmacotherapies, evidence-based effective treatments are limited for relieving dyspnea in cancer survivors. Preliminary evidence supports the potential of respiratory muscle training to reduce dyspnea in cancer survivors, although large randomized controlled studies are warranted. The aims of this article were to review the relevant scientific literature on the potential therapeutic role of respiratory muscle training in dyspnea management of cancer survivor, and to identify possible mechanisms, strengths and limitations of the evidence as well as important gaps for future research directions.

Common and distinct risk factors that influence more severe and distressing shortness of breath profiles in oncology outpatients

BACKGROUND

Shortness of breath occurs in 10%-70% of oncology patients. Very little is known about interindividual variability in its severity and distress and associated risk factors. Using latent profile analyses (LPAs), purpose was to identify subgroups of patients with distinct severity and distress profiles for shortness of breath as single symptom dimensions. In addition, a joint LPA was done using patients' severity AND distress ratings. For each of the three LPAs, differences among the shortness of breath classes in demographic, clinical, symptom, stress, and resilience characteristics were evaluated.

METHODS

Patients completed ratings of severity and distress from shortness of breath a total of six times over two cycles of chemotherapy. All of the other measures were completed at enrollment (i.e., prior to the second or third cycle of chemotherapy). Separate LPAs were done using ratings of severity and distress, as well as a joint analysis using severity AND distress ratings. Differences among the latent classes were evaluated using parametric and nonparametric tests.

RESULTS

For severity, two classes were identified (Slight to Moderate [91.6%] and Moderate to Severe [8.4%]). For distress, two classes were identified (A Little Bit to Somewhat [83.9%] and Somewhat to Quite a Bit [16.1%]). For the joint LPA, two classes were identified (Lower Severity and Distress [79.9%] and Higher Severity and Distress [20.1%]). While distinct risk factors were associated with each of the LPAs, across the three LPAs, the common risk factors associated with membership in the worse class included: a past or current history of smoking, poorer functional status, and higher comorbidity burden. In addition, these patients had a higher symptom burden and higher levels of cancer-specific stress.

CONCLUSIONS

Clinicians can use the information provided in this study to identify high-risk patients and develop individualized interventions.

Distinct Shortness of Breath Profiles in Oncology Outpatients Undergoing Chemotherapy

CONTEXT

Shortness of breath is a distressing symptom that occurs in 10% to 70% of oncology patients. Despite this broad range in its occurrence, little is known about inter-individual variability in shortness of breath and associated risk factors among patients receiving chemotherapy.

OBJECTIVES

Identify subgroups of patients with distinct shortness of breath profiles; evaluate for differences among these subgroups in demographic and clinical characteristics; evaluate for differences among symptom dimensions of shortness of breath, and evaluate for differences in quality of life outcomes.

METHODS

Outpatients (n=1338) completed questionnaires six times over two chemotherapy cycles. Occurrence of shortness of breath was assessed using the Memorial Symptom Assessment Scale. Latent class analysis was used to identify subgroups of patients with distinct shortness of breath profiles.

RESULTS

Four distinct shortness of breath profiles were identified (None [70.5%], Decreasing [8.2%], Increasing [7.8%], High [13.5%]). Risk factors for membership in High class included: history of smoking, self-reported diagnosis of lung disease, having lung cancer, and receipt of a higher number of cancer treatments. Compared to the None class, High class reported poorer physical, psychological, and social functioning.

CONCLUSIONS

Almost 14% of patients with heterogeneous types of cancer receiving chemotherapy had persistently high occurrence rates of shortness of breath for almost two months. In addition, compared to the Decreasing and Increasing classes, the High class' episodes of shortness of breath were more frequent and more severe. Clinicians need to assess all oncology patients for shortness of breath and provide targeted interventions.