A strong recommendation to use neoadjuvant therapy more routinely was one of the key messages from the St Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer.
Many of the recommendations provide the potential to de-escalate further treatment and reduce toxicities for patients.
Co-author Associate Professor Prue Francis, head of medical oncology in the breast service at the Peter MacCallum Cancer Centre, said a neoadjuvant approach was endorsed for HER2 positive and triple negative breast cancer.
“So in those tumour subtypes, which might potentially respond to drug therapies, the panel were suggesting this could be more of a standard of care once the tumour was either stage ll or stage lll.”
Associate Professor Francis told the limbic the approach would not suit every situation.
“It wouldn’t immediately sit comfortably with some women. The idea of leaving a tumour in your body, unoperated for six months, might make some patients anxious.”
Additionally, the approach would work better in some centres than others.
“The sequence of doing neoadjuvant therapy first and then doing local therapies after the drug therapy is more difficult than to do the standard sequence of therapies with the surgery first. So unless you have a very experienced team that does it regularly, then it’s probably not something that will be done well.”
Associate Professor Francis said another recommendation was to move to hypofractionated radiation schedules in women over 50 years.
“Traditionally when women had radiation to a conserved breast, their treatment often went on for five to six weeks – daily, Monday to Friday treatments. In the hypofractionated schedule, radiation might be completed in 16-18 treatments – so more like three and a half weeks.”
“If people can be safely and effectively treated with fewer treatments, most patients would prefer that.”
“Instead of a one size fits all we’re really trying to tease out which patients could potentially have less toxicity by having less treatment and do just as well, and those who might need more treatment to have better outcomes.”
A recommendation to accept ‘no ink on the tumour’ instead of wider margins also had the potential to reduce the number of repeat surgeries, resources and stress.
“As long as it’s not at the margin, that patient is expected to get radiation and drug therapy which all improve local control as well so the importance of margins, which can affect cosmesis as well as the number of operations, is changing over time.”
Adjuvant bisphosphonate therapy was also recommended for postmenopausal women given it could slightly reduce recurrence rates and improve survival.
Associate Professor Francis said while potentially applicable to a large number of women, bisphosphonates were not currently on the PBS for that indication.
However given the low cost of generic bisphosphonates, some women with a high risk of recurrence might be very motivated to self-fund.
Associate Professor Francis said implementation of recommendations about gene expression signatures was also influenced by funding arrangements.
While almost a standard of care in North America, the use of multi-gene assays was relatively uncommon in Australia due to the costs.
“Nowadays we’re looking less at the size of tumours and more at the biology of tumours. Some of those patients might be spared chemotherapy if they had a multi-gene assay showing a low risk of recurrence with endocrine therapy alone.”