Explaining inconsistent results in cancer quality of life studies: the role of the stress-response system

This study tests the hypothesis that avoidance and intrusion play different roles in health-related quality of life (QoL) in women who have undergone breast cancer surgery. We assessed QoL (RAND-36), avoidance, intrusion, and total cancer-related distress (Impact of Event Scale) in 83 women at 3, 6, 9, and 12 months after mastectomy. Social functioning and role limitations improved over time; physical functioning, general health, and mental health did not change; vitality initially improved folllowed by a decrease to a below initial level; physical pain initially improved followed by a decrease to an above initial level. Cancer-related distress remained high during follow-up. Individual variation in QoL as assessed across the four measurement times was associated with individual variation in intrusion but not with individual variation in avoidance. Baseline intrusion did not predict the subsequent course of QoL but high initial avoidance was associated with an unfavourable time course in physical functioning, social functioning, and general health. Hence, variation in intrusion over time explains variation in QoL while baseline avoidance predicts the subsequent course of QoL. The findings provide new insight into the relationship between the stress-response system in QoL and women with breast cancer. Copyright (C) 2007 John Wiley & Sons, Ltd