'We can now predict breast cancer recurrence just 2 weeks after diagnosis'—could results from a new trial upend SOC?

By now, most oncologists are familiar with the POETIC trial—but a new analysis is giving it renewed relevance, especially for patients with ER+/HER2+ breast cancer.^[]

According to retired breast cancer surgeon and patient advocate Liz O’Riordan, FRCS, PhD, a game-changing discovery out of the UK could shift how we identify recurrence risk before surgery—and potentially spare thousands of women from unnecessary treatment.

"We can now predict breast cancer recurrence just 2 weeks after diagnosis," Dr. O'Riordan said in an Instagram Reel. "A major new study has found that short-term hormone therapy before surgery reveals how a tumor will behave, and that could spare thousands of women from unnecessary treatment and the brutal side effects that come with it."

More about the research

Researchers at the Institute of Cancer Research (ICR) analyzed tumor samples from 213 patients who participated in the POETIC trial, which involved giving ER+/HER2+ patients 2 weeks of hormone therapy prior to surgery.^[]

Something unexpected emerged: Tumor subtypes changed in that brief window of time—and those shifts correlated with prognosis.

Specifically, the study focused on Luminal A (favorable prognosis) and Luminal B (higher recurrence risk) subtypes:^[][]

• 19% of tumors remained Luminal A after 2 weeks of treatment: Patients had an excellent prognosis, with no need for CDK inhibitors.

• 28% of Luminal B tumors converted to Luminal A within 2 weeks: Patients also had good outcomes and could continue with standard hormone therapy care.

• 6% of tumors remained Luminal B: These patients had significantly higher recurrence risk and would likely be candidates for CDK inhibitor therapy.

Why this matters for your patients

About 200,000 women globally are diagnosed with ER+/HER2+ breast cancer per year worldwide. CDK inhibitors can be effective but come with significant toxicity and cost.

Until now, we’ve lacked a fast, affordable, and personalized way to predict who actually benefits from them. This new analysis suggests that:

• A 2-week course of pre-op hormone therapy may stratify risk early.

• This therapy provides a biological “test run” without immediately escalating to CDK inhibitors.

• This therapy helps prevent under- and over-treatment in a molecularly heterogeneous disease.

The bottom line for doctors

If validated further, this approach could serve as a new clinical decision-making tool, refining how candidates are identified for escalated therapy.

The simplicity of adding 2 weeks of hormone therapy pre-op may offer significant downstream benefits: better targeting of CDK inhibitors, fewer adverse effects, and more personalized care.

As Dr. O’Riordan put it: "No more guesswork, no more overtreatment. Just the right drugs at the right time for the right tumor.”