This study makes several important contributions to clinical care and research focusing on post-treatment lung cancer survivors. In contrast to studies using general population norms, this study compares HQOL in lung cancer survivors with that of closely matched controls, thereby improving the interpretation of the specific impact of disease and treatment exposure. These analyses also build upon prior research [5
] by examining correlates of HQOL and by interpreting results in terms of clinical importance, thus enhancing the meaningfulness of these findings for clinical care.
Most encouraging, our results indicate that lung cancer survivors diagnosed with early stage non-small cell disease who underwent resection with curative intent and remain without evidence of disease have, on average, mild physical impairments in quality of life compared to closely matched controls who have not been diagnosed and treated surgically for early-stage lung cancer. The effect size (d
-value) approaches a small clinically important difference [28
] (see ), indicating that survivors reported relatively mild, but noticeable, disease and treatment related physical sequelae. Our regression analysis also highlights specific subgroups of lung cancer survivors that experience clinically meaningful deficits in HQOL outcomes. Similar to prior findings [5
], survivors who experienced dyspnea were more likely to report lower physical HQOL as well as those who reported symptoms of depression and a greater number of comorbid conditions. In contrast with other studies [5
], a greater amount of time since diagnosis was not identified as a correlate of physical HQOL suggesting some stability in HQOL following surgical recovery and the early phase of lung cancer survivorship. Symptoms of depressed or anxious mood were associated with lower levels of mental health HQOL, whereas older age and being male were associated with higher levels of mental health HQOL. These are important findings with regard to long-term HQOL outcomes for early stage, completely resected, lung cancer survivors.
The study indicates that a subgroup of lung cancer survivors may have greater need for multi-disciplinary rehabilitation and supportive care focused on improving physical functioning. To date, preliminary studies of pulmonary rehabilitation programs for post-operative lung cancer patients have found positive effects on functional ability, peak exercise capacity, and dyspnea [29
], supporting the need for further research on the risks and benefits of exercise and pulmonary rehabilitation following lung cancer surgery. In addition, post-treatment screening for anxious and depressed mood would provide a foundation for improved management of mental health impairments in HQOL.
Study Strengths and Limitations
Strengths of the study include a good survey response rate (65%) and use of a well-validated HQOL instrument. The study also examined lung cancer survivors who were 1–6 years post treatment, an understudied yet important timeframe in terms of HQOL outcomes. Moreover, comparison of lung cancer survivors' HQOL with an age-, sex-, and education-matched comparison sample enrolled in a lung cancer screening trial permitted estimation of the specific effects on HQOL of lung resection and cancer treatment while helping to control for the potentially confounding effects of smoking history and associated comorbid medical conditions. In addition, use of clinically-relevant interpretation guidelines focuses the results in terms of clinical importance for physicians providing long-term surveillance and management of lung cancer survivors.
Several limitations to the study should be noted. First, the present findings apply only to longer-term (1–6 year post-treatment) survivors of stage I NSCLC with no current evidence of disease. Second, the cross-sectional research design prohibited examination of the causal direction of associations between selected correlates and HQOL. While study participants and decliners were similar in terms of demographic and medical factors, fewer current smokers participated, a factor that could positively bias HQOL estimates. Future prospective studies should closely examine several HQOL appraisal processes such as response shift [34
], level of satisfaction, and evaluation of the importance [35
] of other HQOL domains. Similarly, assessment of perceptions of benefits and change of perspective from the cancer experience may provide a more nuanced picture of the quality of life in lung cancer survivors.
These findings provide clinically useful information for physicians managing post-treatment care of early stage, resected lung cancer survivors. While our finding that lung cancer survivors overall do not experience major deficits in HQOL is encouraging, multi-disciplinary post-treatment follow-up beyond the initial treatment phase is warranted as the presence of either ongoing dyspnea or depression is likely to be associated with clinically meaningful decrements in physical functioning for these survivors. Further research is needed to determine if mood disorder screening and management as well as pulmonary rehabilitation programs that have been shown to improve dyspnea [36
], result in improved HQOL outcomes for lung cancer survivors. In addition, while the growing use of minimally invasive surgical procedures is likely to reduce post-surgical sequelae, the rising use of radiation therapy and neoadjuvant and adjuvant chemotherapy warrants examination of the effects of multi-modality treatment regimens on long-term HQOL outcomes among lung cancer survivors. These findings guide the development of clinical guidelines needed for the management of post-treatment care among the growing cohort of lung cancer survivors.