The American Society of Clinical Oncology (ASCO) has issued a new clinical practice guideline on chemotherapy and targeted therapy for women with HER2-negative advanced breast cancer.

The guideline provides detailed, evidenced-based information on the efficacy and side effects of various therapies.

"In releasing this guideline, our aim is to improve both the length and quality of patients' lives," said Ann H. Partridge, MD, MPH, co-chair of ASCO's expert panel that developed the guideline.

"Although no clear chemotherapy winner emerged – the guideline will help doctors and patients choose the best therapy based on what treatment would be most tolerable and convenient for the patient."

Nearly 80 percent of women with advanced breast cancer are HER2-negative, meaning that they have normal levels of HER2 protein in their tumour and are not candidates for HER2 targeted therapies.

The new ASCO guideline assesses systemic therapy options for these women about to begin a chemotherapy treatment regimen.

"There are many different types of treatments available but some are unnecessarily toxic," said Ian E. Smith, MD, co-chair of ASCO's expert panel that developed the guideline.

"This guideline emphasises that breast cancer can often be controlled with less intensive approaches that offer a better quality of life for patients. Patients should be involved in decisions about their own treatment and also encouraged to participate in clinical trials whenever possible."

The guideline states and recommends:

Hormone therapy should be offered as the standard first-line therapy for women with hormone receptor positive advanced breast cancer, except for immediately life-threatening disease or if there is concern about resistance to hormone therapy.

Different chemotherapy agents should normally be given sequentially, rather than in combination, to reduce side effects and preserve quality of life.

Doctors and patients should make treatment choices together, taking into consideration prior therapies, side effects, schedule, other chronic conditions (e.g., heart disease), and patient preference because there is no single optimal chemotherapy.

Bevacizumab should only be considered with single-agent chemotherapy when there is immediately life-threatening disease or severe symptoms (bevacizumab, which has been shown to shrink tumours and delay disease progression in some patients, but does not extend overall survival, is not approved by the Food and Drug Administration for the treatment of breast cancer in the United States).

No other targeted agents should be used in addition to, or as a replacement for, chemotherapy (one targeted drug, everolimus, is approved for use with hormonal therapy exemestane for women with hormone receptor positive breast cancer but earlier in the course of the disease, when the cancer may still be responsive to hormonal therapy).

Palliative care should be initiated early and offered throughout the continuum of care.

As no cure is yet available for advanced breast cancer, doctors should encourage all eligible patients to participate in clinical trials and potentially benefit from promising experimental treatments.

To develop this clinical practice guideline, an ASCO Expert Panel conducted a formal systematic review of relevant medical literature published from 1993 through May 2013.

The review considered 20 systematic reviews and/or meta-analyses and 59 randomised clinical trials on therapies for women with advanced HER2-negative breast cancer.

The guideline, Chemo- and Targeted Therapy for Women with HER2-Negative (or unknown) Advanced Breast Cancer: American Society of Clinical Oncology Clinical Practice Guideline was published in the Journal of Clinical Oncology.

Source: ASCO