Quality of life is an important factor in the assessment of cancer therapy, but it is difficult to define and measure. The Functional Living Index-Cancer (FLIC) was designed specifically for cancer patients under treatment. The Eastern Cooperative Oncology Group (ECOG) mounted a pilot study to assess the feasibility and sensitivity of the patient-oriented FLIC scale for assessment of quality of life. The results of this study show that the FLIC scores correlate with the functional status of patients on treatment: high scores on the FLIC prior to therapy were found to correlate with good performance status (p = 0.0001), and decreases in the FLIC score during therapy correlated with a decline in performance status (p = 0.0001), with poor performance status (p = 0.0002), and greater than 5% recent weight loss (p = 0.004). However, there was poor compliance to completion of the instrument, indicating a need for future research into this aspect of assessing quality of life in the cooperative group setting.