Breast Cancer Connect recently hosted a discussion with oncologists regarding high-risk early breast cancer.

Below are some highlights from the discussion:

Objectively discussing the risk of disease recurrence is important.

• “[I] Inform them that they appear to have higher risk breast cancer, meaning that there would be a higher rate of recurrence. Would most likely need neoadjuvant/adjuvant chemotherapy, or targeted therapy or endocrine therapy, in addition to surgery and radiation.”
• “I am honest and explain their risk for recurrence is high, sometimes >50% chance so we need to do all we can upfront to get the best chances of beating this thing.”

Oncologists explained that increased toxicity is a key tradeoff for reduced risk of recurrence.

• "Benefits is decrease in recurrence rates. The price to pay is more toxicity: GI side effects and neutropenia.”
• “The benefit is a reduction in the risk of systemic recurrence, with improvement in disease-free survival, which is maintained and actually deepens with longer follow-up as recently shown. The drawbacks are the potential side effects, as well as compliance given the long duration of treatment."

Adjuvant CDK4/6 inhibition may reduce treatment options for metastatic disease.

• “You can ‘burn the bridge,’ meaning, If they recur or are metastatic, I don't know that there are robust data to use it a second time.”

Insurance coverage and “financial toxicities” are substantial barriers to care that must be overcome. Oncologists noted that GI-related AEs are difficult but not impossible to overcome.

• “Cost is always a problem especially if they are underinsured. The diarrhea [….] is a concern that can be overcome but takes some work.”
• “Most patients do quite well in regard to tolerability and gain significant benefit in long-term outcomes. In patients with AEs, dose reductions and modifications can be done. No drug access challenges seen overall.”

Endocrine therapy plays an integral role in treatment paradigms for early breast cancer.

• “Endocrine therapy plays a very important role, given the large benefit in reducing risk of recurrence.”
• “[It is] essential for ER-positive breast cancer. All such patients should receive it.”

Patient adherence to endocrine therapy can be difficult, so oncologists say managing AEs is crucial to patient buy-in.

• "Endocrine therapy is the backbone for ER+ breast cancer. Compliance can be an issue; therefore, managing side effects effectively is the key.”

For oncologists, the Ki-67 score is unimportant when choosing whether to initiate CDK4/6 inhibitor treatment.

• “Ki-67 is a prognostic marker. It is not, however, an independent marker, and it is not performed routinely by every institution. […]. However, the FDA has liberalized the criteria for candidates for adjuvant abemaciclib, and therefore Ki-67 is not really utilized in this setting.”
• "Ki-67 has been one of the criteria for abemaciclib use in high-risk ER+ breast cancer patients. Beyond that, Ki-67 in itself does not change my management.”