Breast cancer: risk of death higher if treatment time frames not followed

An increased risk of death from breast cancer has been found in women if treatment interval guidelines are not followed, according to research published in the Medical Journal of Australia.

The research examined associations between breast cancer survival and timeliness of treatment, and found that the risk of death from breast cancer is 43% higher for women who had at least one treatment interval longer than the recommended treatment time frames.

“Despite recent efforts to improve therapy, between 33% [and] 52% of women diagnosed with breast cancer do not receive timely treatment,” said Dr Kou Kou, author of the study and Senior Research Officer of Epidemiology at Cancer Council Queensland.

“Our study shows that any delay in commencing or continuing treatment is associated with poorer survival.”

Researchers at Cancer Council Queensland conducted a population-based cohort study of women aged 20–79 years diagnosed with invasive breast cancer between 1 March 2010 and 30 June 2013, as recorded on the Queensland Cancer Register.

“We compared treatment intervals for each participating woman with the guidelines,” said Professor Peter Baade, a biostatistician and senior manager of descriptive epidemiology at Cancer Council Queensland.

“We found the risk of death from breast cancer was significantly greater for women who underwent surgery more than 29 days after diagnosis, or commenced chemotherapy more than 36 days after surgery, or commenced radiotherapy more than 31 days after completing adjuvant chemotherapy, compared to women who received treatment before the corresponding time points.”

The research suggests that delays to any of these milestones increase the risk of death, with factors such as living regionally, not having private health insurance, and even requiring treatment over the festive season, likely to influence delays.

“Therefore, it is vital that the 2020 Australian guidelines for the treatment for early breast cancer are followed as closely as possible,” Kou said.

The 2020 Australian guidelines for the treatment for early breast cancer outlines six treatment intervals:

• diagnosis to neoadjuvant therapy (neoadjuvant systemic therapy should start as soon as diagnosis and staging is complete, ideally within two to four weeks);
• neoadjuvant therapy to surgery (surgery should be performed within four to six weeks of neoadjuvant systemic therapy, allowing for recovery from myelosuppression);
• diagnosis to surgery (surgery should be performed within one month of decision to treat with surgery for women who do not receive neoadjuvant therapy);
• surgery to chemotherapy (adjuvant chemotherapy should commence within four to six weeks of surgery);
• surgery to radiotherapy (women who have completed definitive surgery for breast cancer should commence radiotherapy as soon as possible after wound healing, and within eight weeks of surgery if no adjuvant chemotherapy received);
• chemotherapy to radiotherapy (women who have completed definitive surgery for breast cancer should commence radiotherapy within three to four weeks of completing adjuvant chemotherapy).
   

“The clinical evidence is in: these guidelines save lives, so we need to make sure they are being followed by clinicians to give their patients the best chance of survival.”

Image credit: iStock.com/Nattakorn Maneerat