High-risk HR + early breast cancer recurrence reduced with new drug for the first time in years

ESMO 2020 studies show that adding abemaciclib to hormone therapy increases the risk of cancer recurrence in high-risk early hormone receptor positive (HR +) human epidermal growth factor receptor 2 negative (HER2-) breast cancer patients Will decrease.

“This is the first time in more than 20 years that we have witnessed advances in this form of adjuvant therapy. breast cancer“The lead author, Professor Stephen Johnston of the NHS Foundation Trust at the Royal Marsden Hospital in London, UK, said. cancer It is the most common form of breast cancer and affects 70% patient, Most have been diagnosed with early illness.

“Many of these patients can be cured with currently available treatments: surgery, radiation therapy, chemotherapy, and hormone therapy, but about 20% have high-risk disease and in the first decade. It recurs locally in the breast or elsewhere in the body. Years of treatment, “he explained.

“Patients with these high-risk early-stage breast cancers have shown some resistance to hormone therapy and, despite everything we are doing now, have an early recurrence,” Johnston said. Said. “CDK 4/6 inhibitor, abemaciclibChanged the way we treat Metastatic breast cancer Over the past few years, it has overcome primary endocrine resistance and improved survival. Therefore, it was a clear step to see if adding abemaciclib to hormone therapy in high-risk patients with early-stage breast cancer could reduce the risk of cancer recurrence. “

The International Phase 3 Monarch study enrolled 5637 patients with HR + HER2 early-stage breast cancer with clinical and / or pathological risk factors at high risk of recurrence. After the first-line treatment was completed, abemaciclib (150 mg twice daily for 2 days) plus endocrine therapy or endocrine therapy only was blindly randomized.

“We found a 25% reduction in cancer recurrence in the first two years when abemaciclib was added. hormone Treatment compared to Hormone therapy Johnston reported. 11.3% of patients during this period Control group There is a recurrence of the cancer compared to 7.8% of the cancers in the abemaciclib group, and an absolute difference of 3.5% corresponds to a 25.3% reduction in risk. Most of the reduction occurred, especially at the site of distant metastases to the liver and bone.

“This is the first study to show that the addition of a CDK4 / 6 inhibitor to endocrine therapy significantly improves invasive disease-free survival in adjuvant therapy,” said Associate Professor of Medical Oncology, University of Milan, Italy. Professor and ESMO Guidelines Committee.

“This is a very important trial and the findings will change practice. Early when high-risk HR + HER2- is approved. milk Cancer will add two years of abemaciclib to endocrine therapy as a new standard of care for these patients, “he suggested.

Curigliano suggests that in addition to the number of positive lymph nodes, tumor size, histological grade, and Ki-67 (a marker of growth), it is interesting to include the genetic signature in the assessment of high-risk patients. did. According to Johnston, tissue and plasma samples were collected from all study participants for translational research, including examining genomic signatures and responses to abemaciclib.

“Safety data is important, especially the number of patients treated with abemaciclib who have been forced to discontinue or lose weight due to side effects,” Crilliano said. A total of 463 (16.6%) patients discontinued abemaciclib due to adverse events, most commonly diarrhea. Of these, 306 continued endocrine therapy. The protocol allowed us to reduce the dose from 150 mg to 100 mg twice daily as needed. He states: “Treatment compliance will be an important issue to consider in the actual population of patients when this treatment is approved and used. Clinical practice“

“It’s important to understand if chemotherapy could be applied to this group of patients treated with CDK4 / 6 inhibitors in the future,” said Crilliano. This is a randomized clinical trial. It will need to be investigated in a trial, “he added.