De-Escalated Treatment for Early Breast Cancer Continues to Gain Momentum

Resumen del Estudio

The number of women skipping sentinel lymph node biopsy (SLNB) for early breast cancer doubled over a 5-year period to become the predominant strategy for low-risk disease, a prospective study showed.

The proportion of patients who omitted SLNB increased from 25.5% in 2020 to 50.9% in 2025. Over the 5-year period, 69% of women ages 70 or older omitted SLNB, as did a third of patients ages 50-69. Almost 80% of women who omitted SLNB had partial breast irradiation (PBI) or no radiation therapy (RT).

More than 90% of women who underwent SLNB had no evidence of lymph node involvement, and a majority of those patients had PBI or no RT. Only three of 62 patients with positive SLNB results underwent axillary lymph node dissection (ALND), continuing a recent trend toward less aggressive management for low-risk breast cancer, said Matthew Hager, MD, of the Mayo Clinic in Rochester, Minnesota, at the American Society of Breast Surgeons meeting in Seattle.

Tendencias en la Omisión del SLNB

“We saw a significant increase in patients selected for sentinel lymph node surgery omission from 2020 to 2025, initially in the 70-and-older age group and more recently in the 50-to-69 age group,” said Hager. “Importantly, rates of radiation therapy and use of whole-breast irradiation did not increase. In fact, patients who were selected for omission of sentinel lymph node surgery had lower-risk disease and were more likely to have partial breast or omission of radiation compared to those who underwent sentinel lymph node surgery.”

“With a multidisciplinary team approach, we are successfully de-escalating axillary surgery in appropriately selected patients without escalating radiation,” he added.

Conclusiones del Estudio

The findings add to a growing body of evidence that treatment de-escalation is feasible and safe for favorable-risk early breast cancer, said Youssef Zeidan, MD, PhD, of the Lynn Cancer Institute and Baptist Health South Florida in Boca Raton.

“Endocrine therapy alone or in combination with radiation therapy represents a clinically viable approach,” Zeidan, an expert for the American Society for Radiation Oncology, told MedPage Today. “However, the optimal strategy requires careful multidisciplinary deliberation that incorporates patient preferences and individual risk profiles.”

Estudios Recientes

In two recent studies of axillary lymph node surgery omission — SOUND and INSEMA — most patients received whole-breast irradiation (WBI), he noted. Omission of RT warrants particular caution in younger patients given their increased risk of local recurrence. Ongoing analysis of two recently completed clinical trials — EUROPA and DEBRA — is expected to help clarify optimal management strategies for patients with favorable-risk disease.

Recomendaciones Precedentes

A decade ago the Society of Surgical Oncology Choosing Wisely guidelines recommended against routine SLNB for patients older than 70 with low-risk early breast cancer. The SOUND and INSEMA trials extended the evidence supporting omission of SLNB to women older than 50, Hager noted. Additionally, several studies have demonstrated the safety of de-escalated RT for low-risk early breast cancer.

“Many of these trials omitting sentinel lymph node surgery generally required whole-breast irradiation, raising concern that omission of sentinel lymph node surgery could lead to escalation of radiation,” he said.

Implementación de Políticas

With input from a multidisciplinary team, Mayo Clinic implemented a policy of SLNB omission in low-risk patients, including agreement not to escalate RT. Hager reviewed findings from an analysis of the policy and the impact on RT for appropriately selected low-risk patients.

The analysis included 1,016 patients treated for low-risk breast cancer at Mayo Clinic from 2020 through 2025. Eligible patients 50 or older had tumors less than 5 cm and clinically node-negative, estrogen receptor-positive/HER2-negative breast cancer that was treated with breast-conserving surgery. Data analysis included type of axillary surgery (SLNB, ALND, or none) and type of RT (WBI, PBI, or none).

El análisis mostró que 679 pacientes tuvieron SLNB y 337 no. Patients who did not have SLNB were older (76 vs 64), less likely to have clinical T2 disease (6.5% vs 19.1%), more likely to have grade I disease (51.5% vs 40.1%), and a lower median proliferation score (8.0% vs 10.0%). Pathology confirmed T2 disease in more patients who had SLNB (18.6% vs 9.5%) and showed that more patients with SLNB had lymph node involvement (pN1, 9.1% vs 0).

En 2020, una mayoría de pacientes de 70 o más años omitieron SLNB (52.9%) en comparación con solo el 1.3% de los pacientes más jóvenes. Para 2022, la tasa de omisión aumentó al 79.4% para pacientes de 70 o más años. En contraste, la tasa de omisión en pacientes más jóvenes se mantuvo alrededor del 1% hasta 2023, cuando alcanzó el 3.2%, antes de aumentar al 14.6% en 2024 y al 32.8% en 2025.

A pesar del aumento en la omisión del SLNB, la cantidad de RT más extensa no aumentó, ya que el 51% de los pacientes recibió PBI y el 27.5% no recibió RT. Among patients who underwent SLNB and had no evidence of lymph node involvement (pN0, n=617), 45.6% had PBI and 8.0% had no RT.

En el grupo mayor, 291 de 421 pacientes evaluables (69.1%) no se sometieron a SLNB, casi la mitad de los cuales recibieron PBI (48.6%) y un 30% adicional no recibió RT. En el grupo más joven (n=595), solo el 7.7% evitó SLNB, pero el 11% también omitió RT y el 66.7% recibió PBI. Incluso en los pacientes más jóvenes que se sometieron a SLNB, la mayoría recibió PBI (44.5%) o no RT (5.8%).

Disclaimer

Este artículo está destinado únicamente a fines informativos y no debe considerarse un consejo médico. Siempre consulte a su médico u otro proveedor de salud calificado con cualquier pregunta que pueda tener sobre una afección médica.

Fuente: https://www.medpagetoday.com/hematologyoncology/breastcancer/121262