Neoplasms

Skin and Connective Tissue Diseases

All Conditions

Breast Neoplasms

Breast Diseases

Skin Diseases

All Drugs and Chemicals

Estrogens

Progesterone

Neil Carleton

Priscilla McAuliffe, MD, PhD

This prospective study recruits patients with ER+/HER2-, non-metastatic breast cancer who omit upfront surgery in favor of primary endocrine therapy for sample collection and prospective circulating tumor DNA (ctDNA) measurement to guide disease surveillance.

Age is one of the most important risk factors for the development of breast cancer. Nearly a third of all breast cancer cases occur in older women (aged ≥ 70 years), with most cases being estrogen receptor-positive (ER+). Such tumours are unlikely to be the ultimate cause of death for older women, particularly when considering other comorbidities. Our group has recently shown that risk of breast cancer-related mortality is only around 3% for older women who forego upfront surgery and instead treated with primary endocrine monotherapy. However, with omission of surgery, surveillance for tumor growth or treatment failure is important but requires patients (and their caregivers) to have regular imaging and to see their oncology team every 3 months, which can be quite burdensome. Thus, this study employs a ctDNA surveillance scheme to monitor for potential tumor growth. Partnering with Natera, this study uses a bespoke, tumor-specific ctDNA assay (Signatera) to monitor for changes in ctDNA dynamics while the patient is on endocrine therapy.

This study is for patients who choose not to undergo primary surgical intervention and are managed medically on primary endocrine therapy (any endocrine therapy permitted). Patients will undergo Signatera testing at the time of regularly scheduled clinic follow-up visits and/or at the time of surveillance imaging, which will occur every 3-6 months. Patients will also be asked to complete regular surveys while participating in the study.

Patient blood to track ctDNA longitudinally over time as well as any tissue samples that the patient may have (including core biopsy samples and/or surgical specimens should the patient and their treating physician decide to undergo salvage surgery at any point).

Longitudinal ctDNA Surveillance for Older Women With ER+ Breast Cancer Who Omit Surgery

Longitudinal ctDNA Monitoring in Older Women With ER+ Breast Cancer Who Forego Upfront Surgery in Favor of Primary Endocrine Therapy

Proportion of patients with ER+/HER2- breast cancer who omit upfront surgery in favor of primary endocrine therapy who have any ctDNA positivity using Signatera assay.

The length of time after treatment initiation that patient is alive and without any evidence of tumor progression as defined by RECIST1.1 criteria. Per RECISIT v1.1: Progressive Disease (PD): ≥20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). The sum must also demonstrate an absolute increase of ≥5 mm. The appearance ≥1 new lesion(s) is considered progression.

BCSS is defined as the length of time from the date of diagnosis through the end of follow up that patients are free from breast cancer-related mortality.

The length of time from the date of diagnosis through the end of follow up that patients are still alive.

This assessment is a 16 item questionnaire using Likert scale (0-4) measured with each ctDNA blood draw. Score ranges from 0-64 with higher scores indicative of higher quality of life / asymptomatic from cancer-related therapy.

Study title	NCT ID	Conditions	Interventions	Eligibility	Organization	Link
Longitudinal ctDNA Surveillance for Older Women With ER+ Breast Cancer Who Omit Surgery	NCT05914792	Breast Cancer		70 Years -	University of Pittsburgh
Longitudinal ctDNA Surveillance for Older Women With ER+ Breast Cancer Who Omit Surgery	NCT05914792	Breast Cancer		70 Years -	University of Pittsburgh

Spots Global Cancer Trial Database for progesterone receptor (pr+)