The first study to compare survival between women with breast cancer treatment was based on consensus guidelines and those whose treatment was not shows that adherence to established guidelines improves survival and reduces risk of recurrence, according to an article published online August 2nd by the Journal of Clinical Oncology.

The study retrospectively examined whether systemic therapy prescribed after surgery for women with early-stage breast cancer was consistent with treatment guidelines established at the time. Systemic therapy included chemotherapy and hormonal therapy.

Using medical records from Canada’s national health care system, Dr. Hebert-Croteau and her colleagues compared survival between 1,002 women with early breast cancer whose systemic treatment was delivered according to guidelines developed at the 1992 St-Gallen conference in Switzerland, and 380 women whose treatment differed from those guidelines. The study also included 159 women whose guideline adherence was unknown. The women were diagnosed between 1988 and 1994 with node-negative invasive breast cancer.

The St-Gallen guidelines continue to be updated regularly and are considered among the best guidelines available. The guidelines stipulate whether a woman with node-negative breast cancer should, after surgery, receive tamoxifen, chemotherapy, neither (as is the case for women at low risk of recurrence), or both, depending on individual risk.

Researchers found that overall survival at 7 years was better among women whose systemic treatment complied with guidelines, especially for those at moderate risk of recurrence. Among those patients with moderate risk of recurrence, the 7-year survival was 88 percent for women who received treatment consistent with guideline recommendations versus 79 percent among those whose therapy did not.

In addition, more women whose treatment differed from treatment guidelines experienced recurrence by 7 years than those whose therapy adhered to the guidelines. For those at moderate and high risk of recurrence, the recurrence rate at 7 years was 36 percent and 42 percent respectively when treatment did follow guidelines, versus 17 percent and 36 percent when treatment followed guidelines.

“Women treated for node-negative breast cancer according to consensus recommendations for systemic therapy experience a significant improvement in survival at 7 years,” said Nicole Hebert-Croteau, MD, PhD, lead author of the study. “Our associations support the current movement for developing, updating, and disseminating such recommendations.”

Underuse of systemic therapy exists to some degree ?at any cancer center ? due to the complex nature of cancer care. For example, when a patient’s baseline prognosis is good, a physician may elect not to prescribe systemic therapy in efforts to avoid toxic side effects. Dr. Hebert-Croteau noted that patients may also have other medical problems that might influence the treatment recommendation.

An accompanying editorial by Rebecca A. Silliman, MD, PhD, noted that translating clinical guidelines into practice is often a slow and complex process. She suggested that interventions that use small-group, case-based approaches that incorporate role-playing and discussion are needed to change provider behaviors.

“Although evidence-based guidelines are a necessary beginning, they are not sufficient in and of themselves to change practice,” Silliman said. “What is required is a much more comprehensive approach that incorporates not only knowledge, but also builds skills and affects attitudes.”

Silliman also noted that the results of this study should be interpreted with caution, since they pertain to medical care that was delivered more than a decade ago.