Patients and doctors' views on important endpoints in incurable metastatic breast cancer

Mar 24 2010

Many patients with metastatic breast cancer believe that the primary goal in survival with new treatment should be to prolong life by at least a year over the survival they might expect from using current best therapies, a researcher will tell the seventh European Breast Cancer Conference (EBCC7) in Barcelona today (Wednesday). This finding contrasts with doctors' perception that an additional four to six months' survival is significant enough to consider a new treatment worthwhile.

Dr. Amir Sheik-Yousouf, a resident physician in the Department of Internal Medicine at University of Toronto, Canada, working under the supervision of Dr. Sunil Verma, Chair of Breast Medical Oncology at Sunnybrook Odette Cancer Centre, Toronto, set out to look at what patients and doctors thought were the most important endpoints in incurable metastatic breast cancer, and what degree of benefit from their treatment should be considered to be important. The researchers say that, to their knowledge, this is the first time that the views of these two groups on such a question have been studied.

"We found that patients and doctors held very different views," says Dr. Sheik-Yousouf. "Our research shows that it is essential to have a thorough discussion of treatment goals with patients - they expect a lot from the new therapies that are being developed but need also to understand that many of them are associated with only marginal improvements in survival."

The researchers surveyed 28 breast oncologists and 52 patients with metastatic breast cancer. Among the doctors, 52% believed that overall survival was the most important endpoint to be considered when choosing a treatment, and 48% believed that the most important outcome would be progression-free survival; 48% thought that that the minimum meaningful improvement in overall survival was four to six months, and 44% believed that a two to four month improvement in survival was meaningful.

Sixty percent of the oncologists surveyed believed that their patients also considered an improvement in overall survival to be the most important endpoint. The patients agreed, with 88% feeling that the primary goal of their treatment was to prolong life. However, when it came to the length of time of that survival, major differences with the doctors emerged, with 46% of patients thinking that only more than 12 months additional survival would make taking a treatment worthwhile for them; 17% thought that an extra 10-12 months would be acceptable, and only 10% thought that one to two months additional survival would be the minimal acceptable improvement.                                                                                           

Sixty-three percent of patients also believed that slowing tumour growth was a goal of treatment, and shrinking tumour burden and improving quality of life were also important to 62% of them; 17% thought shrinking tumour size was the most important goal of treatment. Fifty percent felt that improving symptoms and pain were other important therapeutic goals. Among the doctors, 36% believed that, after overall survival, overall quality of life would be the second most important factor to patients with metastatic breast cancer. 

"This was only a small study and needs to be followed up on a larger scale," says Dr. Sheik-Yousouf. "However, the survey highlights major differences in the expectations of the outcome of treatment of metastatic breast cancer between oncologists and patients. We need not only to improve the way we discuss treatment options with patients, but also to ensure that clinical trials of new drugs are designed to meet the expectations of patients and doctors alike. We hope that by sharing the results of our study with our peers, industry, and government we may be able help them better develop new trials and guide their efforts in the approval and funding of new drugs for cancer."