Through neoadjuvant chemotherapy we can downstage tumors, assess drug efficacy, and better segregate women by prognosis status for adjuvant treatment, explained Alexey Aleshin, MD, senior medical director of Oncology at biotech giant Natera.
Through neoadjuvant chemotherapy we can downstage tumors, assess drug efficacy, and better segregate women by prognosis status for adjuvant treatment decisions, explained Alexey Aleshin, MD, senior medical director of Oncology at biotech giant Natera.
Why is chemotherapy a standard-of-care treatment for locally advanced breast cancer when few patients achieve pathological CR?
Early-stage cancer really is treated with surgery; it’s a surgically managed disease. And breast cancer is no exception. The role of chemotherapy, be it in the neoadjuvant or in the adjuvant setting, is to really help eliminate and reduce the burden of disease, be that growth of disease in the neoadjuvant setting or micrometastatic disease in the adjuvant setting.
The history behind widespread adoption of neoadjuvant chemotherapy in breast cancer is compliance, but it really boils down to 3 main uses. The first most widely accepted use is really downstaging the tumor to make it more operable. So before, cancer required a mastectomy. After neoadjuvant chemotherapy, someone would be able to qualify for a lumpectomy.
Additionally, neoadjuvant chemotherapy is used to assess drug efficacy. I think that's the primary purpose of the I-SPY2 study: to see if additional novel therapies added to a base anthracycline-containing regimen in the neoadjuvant setting can improve outcomes for these women. Really to validate that certain classes of drugs may have utility for further study.
And then, really, the last one is to prognosticate. And I think prognostication is difficult. Patients either recur or they don't, so how can we more accurately put patients in 1 of those 2 categories without really waiting for the final outcome. And because of that, neoadjuvant therapy really allows us to set pathological complete response (CR) status at time of surgery and then really better segregate women between favorable prognosis and less favorable prognosis to really help better inform adjuvant treatment decisions.
A great example of this, for example, is triple-negative breast cancer where women who do not achieve a pathological CR are frequently offered a capecitabine regimen in the adjuvant setting to really further reduce their risk of recurrence.