Quality of life during chemotherapy for small cell lung cancer. II. A longitudinal study of the EORTC Core Quality of Life Questionnaire and comparison with the Sickness Impact Profile.

Sixty-two patients with small cell lung cancer, 36-80 years of age, who were receiving chemotherapy during a maximum of one year, were consecutively included in a study of quality of life during treatment. An interim version (C-36) of the EORTC Core Quality of Life Questionnaire (QLQ) was applied for quality of life assessment prior to treatment and every third month during the treatment period. The assessments were related to clinical variables (performance status and tumour response), and compared with results from assessment with the Sickness Impact Profile (SIP). The QLQ was sensitive to differences in clinical status and responded to clinical change over time. In general, the pattern of correlations with SIP lends support to the construct validity of the QLQ. However, some questions arose from the comparison with SIP: QLQ emotional functioning did not change in concordance with SIP, and assessment of social functioning was not optimal prior to treatment. The questionnaire was well accepted by the patients. The EORTC QLQ C-36 constitutes a promising step in the development of a feasible standard instrument for quality of life assessment in cancer clinical trials.