CHICAGO—A Canadian study has shown that men with hormone-resistant prostate cancer have improved global and social function, fewer symptoms, and a greater improvement in quality of life (QOL) measures over time when mitoxantrone(Drug information on mitoxantrone) (Novantrone) is added to prednisone(Drug information on prednisone). A subset of patients who crossed over to mitoxantrone after prednisone therapy had failed also experienced significantly greater improvement in quality of life measures.
“These are interesting results,” David Osoba, MD, said at a quality of life and outcomes symposium sponsored by Northwestern University and Evanston Northwestern Healthcare. Although in the crossover protocol, mitoxantrone was not added until 6 weeks after prednisone had failed, men in the crossover treatment group still showed improvement, “indicating that mitoxantrone alone may have an effect,” said Dr. Osoba, clinical professor, British Columbia Cancer Agency, Vancouver.
This randomized study of 161 men focused on health-related quality of life outcomes rather than standard outcomes such as survival. The study assessed quality of life in five functional domains using the 30-item EORTC QLQ-C30 instrument.
The researchers also used a linear analog self-assessment scale (PROSQOL1) and a prostate-cancer-specific quality of life module comprised of 14 items (QLM-P14).
The primary endpoint of the study was reduction in pain without the need to increase analgesic use over a 3-week period. The results, published in the Journal of Clinical Oncology in 1996, showed that 29% of men who received the drug combination had a reduction in pain, compared with 12% of men receiving prednisone alone. The duration of the response also was longer in the mitoxantrone-prednisone group (11 months vs 5 months).
Results involving other domains of quality of life were discussed at the symposium. Scores on quality of life instruments were obtained at 6-, 12-, and 18-week intervals. These scores were subtracted from pretreatment, baseline measurements, and average treatment differences were computed.
Men who received mitoxantrone and prednisone had significantly better global, physical, and social functioning at all three time intervals. In addition, there was also improvement in emotional and role functioning. These men had significantly less fatigue and anorexia at 12 and 18 weeks, and they experienced less pain, which confirmed the findings presented in the published report of the study.
On the prostate-cancer-specific questionnaire involving 14 items in three domains related to daily functioning, men in the mitoxantrone-prednisone group had less drowsiness and confusion and less difficulty with nocturia interfering with sleep. Statistical significance for all these aspects of quality of life was at the P = .01 level.
Findings also were considered to be significant if a change of 10 points or more was documented between one time period and another on a 0 to 100-point scale using the SF-36 instrument. This degree of change was achieved in social function, insomnia, drowsiness, and pain relief, and it lasted two to three times longer for men in the mitoxantrone-prednisone group.
Patients who crossed over to mitox-antrone also did significantly better than those who had prednisone alone, Dr. Osoba said.
The study showed, therefore, that mitoxantrone plus prednisone not only improved pain management in men with hormone-resistant prostate cancer but also improved other aspects of quality of life, Dr. Osoba said.
