Cancer Patients' Quality of Life Directly Relates to Their Survival

mdash; Patients who feel better live longer, say Mayo Clinic researchers, working with the North Central Cancer Treatment Group (NCCTG), in study results released May 15 as part of the 44th Annual Meeting of the American Society of Clinical Oncology (ASCO).

Mayo Clinic cancer researcher and the study's lead author, Angelina Tan, says the results show quality of life is an independent factor in survival.

"Quality of life appears to affect the survival of cancer patients," says Tan. "If physicians can identify patients who are not doing well, they will be able to intervene and, we hope, improve not only their patients' sense of well-being, but also their length of life."

The researchers compared overall survival with responses from 3,704 patients to one question — "On a scale of 0 to 10, how would you rate your quality of life?" Patients had a variety of cancer types, and the question was asked during their participation in one of 24 different NCCTG clinical trials. The unifying factor for the patients was that all had late-stage disease. All results were converted to a 100-point scale.

The team found that baseline quality of life was a strong predictor of survival. They found a distinct difference when dividing patients by the median score of 83 (6.1 months increased survival time for those with scores greater than or equal to 83). The investigators also divided the group into those with scores of more than 50 and 50 or less, defining those in the 50 or less category as having clinically deficient quality of life. In this analysis, the results were even more striking, with increased survival of 7.5 months for the non-clinically deficient patients. The investigators determined that these numbers were independent of performance status (a traditionally used survival prediction method evaluating a patient's ambulatory status).

This study is one of several similar quality of life studies that are being presented by Mayo Clinic researchers at the ASCO annual meeting.

"Quality of life research is a priority at Mayo," says Jeff Sloan, Ph.D., a cancer researcher at Mayo and the study's primary investigator. "While doctors know that a patient's quality of life is important, these studies show that measuring it is necessary and can predict how patients will do."

Dr. Sloan, Tan and their colleagues at Mayo Clinic and NCCTG hope current and future research will identify both how and when clinicians can best support their patients' feelings of well-being. For example, if the quality of life deficit was identified to be related to patient fatigue and emotional distress, interventions (pharmaceutical, psychosocial, etc.) could be offered to improve patient well-being.

"If quality of life deficits can be identified routinely in clinical practice, it will help patients," says Tan. "Physicians can address the issues leading to a decrease in quality of life, and ideally these interventions will extend survival."

Other researchers included Paul Novotny; Judith Kaur, M.D.; and Jan Buckner, M.D., all from Mayo Clinic. NCCTG researchers included Paul Schaefer, M.D., Toledo Community Hospital Oncology Program, Toledo, Ohio; Philip Stella, M.D., St. Joseph Mercy Health System, Ann Arbor, Mich.; and John Kuebler, M.D., Columbus Community Clinical Oncology Program, Columbus, Ohio.

Related quality of life studies being presented at ASCO include:

Baseline quality of life is a strong prognostic factor for overall survival in patients with advanced stage non-small cell lung cancer, Schild et al.

A quality-of-life assessment of patients participating in phase I clinical trials confirms a decrease during treatment, Atherton et al.

Baseline quality of life is a strong and performance status-independent prognostic factor for overall survival in patients with metastatic colorectal cancer, Turja et al.

Tumor burden is not related to quality of life in patients with metastatic colorectal cancer, Sloan et al.

For more background information on integrating quality-of-life measures into clinical practice, read Mayo's two-part monograph published in the November–December 2005 and November–December 2006 issues of Current Problems in Cancer.

NCCTG is a national clinical research group sponsored by the National Cancer Institute. Its research and administration are based at Mayo Clinic. NCCTG consists of cancer specialists at community clinics, hospitals and medical centers in the United States, Canada and Mexico. The group is dedicated to bringing clinical trials with promising new cancer therapies to communities where patients live.