The frequent use of performance status as a proxy of quality of life is not uncommon (Table 2). In lung cancer patients, it is an important prognostic factor and predictor of survival The history of quality of life studies in lung cancer patients goes back to 1970 when the first article (to our knowledge) was published by Carlens et al using the “vitagram index.” It consisted of two dimensions: x-axis (survival) and y-axis (every month of survival as judged on a scale of performance status ranging from —20 to 20). They found that patients undergoing radical operations had a substantially better survival and performance status. Subsequent studies confirmed that performance status is a good predictor of quality of life or that there is a significant correlation between performance status and psychological, physical, and symptomatic distress. Filling Although the use of performance status has been controversial, correlation between performance status and global quality of life is well established It has also been shown that the number and severity of symptoms increase with worsening performance status. In addition, it has been suggested that psychiatric disorder in lung cancer patients is significantly associated with poorer performance status. Schag et al studied 57 disease-free lung cancer survivors and reported that the Karnofsky Performance Scale (KPS) was the best predictor of quality of life. In contrast, in studying 139 lung cancer patients receiving palliative treatment, quality of life was found to be a much broader concept than was reflected by the KPS, and there was a weak association between the KPS and the quality of life as measured by the EORTC QLQ-C30. Contradictory to these findings, Osoba et al found that performance status as measured by the Eastern Cooperative Oncology Group (ECOG) strongly correlated with several domains of quality of life as measured by the EORTC QLQ-C30.
However, although performance status is not a true measure for quality of life and there is inconsistency in findings, it should be seen as an important predictor of survival and quality of life. This implies that physicians, especially oncologists, should record the performance status of the lung cancer patients in the case notes. They can use either the KPS or the ECOG performance status. Although the ECOG is superior to the KPS, both are valid, easy to score, and take a few seconds to rate.
Table 2—Summary of Selected Quality of Life Studies in Patients with Lung Cancer
|Study (yr)||Design||Treatment||Sample||Quality of Life Measure||Results/Conclusions|
|Ganz et al48 (1991)||Descriptive||Palliative RT+SC, CT+SC||40||FLI-C||Initial QL was found as an independent predictor of survival|
|Eguchi et al38 (1992)||Descriptive||CT||64 cases, 50 control subjects||FLI-C (modified version), designed questionnaire (derived from EORTC)||Significant correlation between PS andpsychological, physical, and symptomatic scores, but not for social aspects|
|Buccheri et al54 (1993)||Descriptive||None, surgery, RT, CT||71 pts and their relatives and phyns||Italian translation of EORTC+3 items for three groups: tolerance, physical feeling, depression, KPS, ECOG||Significant difference among pts, phyns, and relatives; phyns were more optimistic, relatives were more pessimistic; phyns were most reliable raters of treatment tolerance|
|Aaronson et al39 (1993)||Descriptive||CT or RT||354 (305)||EORTC QLQ-C30, ECOG||Validation study; strong correlation between physical and role functioning and fatigue; pts with a better PS and less weight loss, showed significant higher level of physical, role, and cognitive functioning, overall QL, and lower symptoms; no significant change over time.|
|Hollen et al31 (1993)||Descriptive||CT or RT or surgery or no treatment||121 cases, 52 observer||LCSS||Validation study; LCSS demonstrated good reliability and content validity|
|Bergman et al33 (1994)||Descriptive||CT or RT||346 (305)||ECOG, EORTC QLQ-C30, QLQ-LC13||EORTC QLQ-LC13 was found to be valid and useful tool for measuring disease and treatment-specific symptoms in LC pts receiving CT or RT when combined with EORTC core QL questionnaire|
|Ruckdeschel and Piantadosi47 (1994)||Randomized||Preoperative therapy + surgery or Surgery +postoperative therapy||437||FLI-C, KPS||Baseline QL was the strongest prognostic factor for survival; FLI-C sensitive to clinical status and predictor of survival even after correcting for initial PS, stage, and treatment|
|Schaafsma and Osoba45 (1994)||Descriptive||PT||162 (139)||EORTC QLQ-C30, KPS||Cross validation study; the QL found to be much broader concept than the KPS; weak association between KPS and EORTC QLQ-C30; difficulty in breathing has strongest negative impact on QL, and the fatigue the least|
|Buccheri and Ferrigno46 (1994)||Descriptive||Various||471||KPS, ECOG||Validation study; KPS and ECOG are both valid, but the ECOG is superior|
|Celia et al49 (1994)||Descriptive||Various||58||FACT-L, ECOG||Validation study; good internal consistency and sensitive to change in PS|
|Stephens55 (1994), Hopwood and Stephens42 (1995)||Descriptive (main studies randomized)||(a) Two CT policies (b) Two RT policies||(a) 310 SCLS (232); (b) 509 NSCL (423)||Phyns: physical symptoms Pts: RSCL+(3 LC specific questions)||Phyns underestimating the level of severity of the patients’ symptoms; overall pattern of symptom prevalence very similar for two disease; NSCLC patients reported higher levels of chest pain, coughing up blood; SCLC pts reported on average 17.4 symptoms, but NSCLC pts reported 14.3; in Doth, disease number and severity of symptoms increases with worsening PS|