A treatment tested for early-stage breast cancer has been shown to reduce the risk of recurrence by 25 percent, according to the results of a large clinical trial published Friday, representing hope for many patients.
These preliminary results were unveiled at the largest annual conference of cancer specialists, organized by the American Society of Clinical Oncology, ASCO in Chicago. "This is a very important clinical trial and one that will change the practice" of doctors, said Rita Nanda, an oncologist at the University of Chicago, who was not involved in this work. This treatment, ribociclib, is developed by Novartis against the most common type of breast cancer (known as HR+/HR2-).
It is already used (in combination with hormone therapy) for patients with advanced cancer with metastases. The aim of this new study was to test this drug for early-stage cancers (1 to 3).
"One in 3 patients with stage 2 cancer has a recurrence"
Management of this disease usually involves surgery and radiation therapy, possibly chemotherapy, and then taking it for years of hormone therapy. Despite this, "one-third of patients with stage 2 breast cancer (...) will have a recurrence," Dennis Slamon, an oncologist at UCLA, told a news conference in presenting the findings. "And these recurrences can occur up to two to three decades after diagnosis."
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More than 5,000 people participated in the clinical trial, half of whom took ribociclib and hormone therapy, and the other half took hormone therapy alone. According to preliminary results, the risk of recurrence was reduced by 25% with treatment.
A CDK protein inhibitor
Ribociclib is an inhibitor of cyclin D1/CDK4 and CDK6, proteins that affect the growth of cancer cells. Two other CDK inhibitor therapies - palbociclib and abemaciclib - are also approved for metastatic breast cancer.
Abémaciclib has also recently been approved in the United States for early-stage disease, but only for women at high risk of recurrence whose lymph nodes are also affected. Ribociclib could be an option for women with no lymph nodes, Nanda said.
Which profiles to target?
"There will probably be a lot of discussion around the level of benefit for patients, the type of side effects, and patients in whom there is a real benefit from using this type of drug for prevention," Jean-Yves Pierga, head of the medical oncology department at Institut Curie, told a separate press conference.
More than two million breast cancers are diagnosed each year worldwide, and the disease causes more than 600,000 deaths per year. Most diagnoses are made at an early stage.
