Stereotactic Ablative Radiotherapy for Metastatic Breast Cancer

(SABR PRIMER Trial)

Overseen By Sandy Chang

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: British Columbia Cancer Agency

Must not be taking: Cytotoxic chemotherapy, CDK4/6 inhibitors

Disqualifiers: SLE, Systemic scleroderma, IPF, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether stereotactic ablative radiotherapy (SABR), a precise radiation treatment, can effectively control tumor growth in individuals with metastatic breast cancer, which has spread beyond the breast. The researchers are examining patient survival, disease-free duration, and the timing of treatment changes. They aim to identify any specific side effects, such as skin problems, swelling, or nerve issues. Individuals with breast cancer that has spread and can be treated with radiation might be suitable candidates, especially if they are receiving or planning to receive other cancer therapies. As an unphased trial, this study allows patients to contribute to innovative research that could enhance future treatment options.

Do I need to stop my current medications for the trial?

Yes, you will need to stop taking certain medications like cytotoxic chemotherapy, CDK4/6 inhibitors, and T-DXd during the treatment.

What prior data suggests that stereotactic ablative radiotherapy is safe for metastatic breast cancer patients?

Research has shown that stereotactic ablative radiotherapy (SABR) is generally safe for treating breast cancer that has spread. Studies have found SABR to be a non-invasive treatment with a good safety record. For patients with metastatic cancer, SABR has proven effective without major safety concerns. Most side effects are mild, though some patients might experience skin irritation, swelling, or nerve issues. Overall, evidence suggests SABR is well-tolerated and safe for patients, with careful monitoring for any side effects. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Stereotactic Ablative Radiotherapy (SABR) is unique because it offers a highly targeted form of radiation therapy that delivers intense doses directly to metastatic breast cancer sites with precision. Unlike traditional radiation therapy, which often affects larger areas and can have more widespread side effects, SABR focuses on the tumor itself, sparing healthy tissues and potentially leading to fewer side effects. Researchers are excited about SABR because it could improve treatment outcomes by precisely targeting cancer cells while reducing damage to surrounding healthy tissues, offering a promising approach for managing metastatic breast cancer.

What evidence suggests that SABR is effective for metastatic breast cancer?

Research has shown that stereotactic ablative radiotherapy (SABR), the treatment participants in this trial will receive, may help treat metastatic breast cancer. In one study, almost half of the patients did not experience cancer progression for at least six months. Another study found that SABR can help control tumor growth. On average, it took 29 months before the cancer spread widely, and many patients avoided further spread for years. These findings suggest that SABR could be a safe and effective way to manage cancer. ^{1 2 5 6 7}

Are You a Good Fit for This Trial?

This trial is for individuals with metastatic breast cancer, meaning their cancer has spread beyond the original site. Participants should be candidates for radiotherapy and have measurable disease that can be targeted by SABR.

Inclusion Criteria

Able to complete patient reported outcome questionnaires

My breast cancer can be measured and is eligible for radiotherapy.

My breast cancer is confirmed as Stage IV invasive.

Exclusion Criteria

I have had radiation therapy on the same side breast before.

I do not have conditions like SLE, scleroderma, IPF, ataxia telangiectasia, and I am not pregnant.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Radiation

Participants receive stereotactic ablative radiotherapy (SABR) to the whole breast and possibly regional lymph nodes

Duration not specified

Follow-up

Participants are monitored for locoregional control, overall survival, progression-free survival, and radiation-related adverse events

2 years

What Are the Treatments Tested in This Trial?

Interventions

• SABR

Trial Overview The study tests whether Stereotactic Ablative Radiotherapy (SABR) can control tumor growth in metastatic breast cancer patients. It also looks at how long patients live without their disease getting worse and when they might need to change treatments.

How Is the Trial Designed?

Group I: Treatment Experimental Treatment 1 Intervention

SABR treatment to Whole breast +/- regional lymph nodes

Who Is Running the Clinical Trial?

British Columbia Cancer Agency

Lead Sponsor

Trials

181

Recruited

95,900+

Published Research Related to This Trial

Stereotactic ablative radiotherapy (SABR) demonstrated a high local control rate of 91.2% for skeletal metastases in a study of 22 patients, with a median follow-up of 15.6 months, indicating its effectiveness in managing oligometastatic and oligoprogressive diseases.

The treatment resulted in significant pain control for two-thirds of symptomatic patients, with limited toxicities reported, including only two vertebral fractures and one case of grade 3 esophagitis, suggesting that SABR is a safe option for patients with skeletal metastases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Utilization of stereotactic ablative radiotherapy in oligometastatic & oligoprogressive skeletal metastases: Results and pattern of failure. Kam, TY., Chan, OSH., Hung, AWM., et al.[2019]

In a study of 381 patients treated with stereotactic ablative body radiotherapy (SABR) for oligometastatic disease, the incidence of grade 3 or higher toxic effects was found to be less than 5%, indicating a favorable safety profile.

The rates of grade 2 or higher toxic effects were 18.6%, which is lower than the previously reported 29% in the SABR-COMET trial, suggesting that SABR may have acceptable toxicity levels and supports further research in larger trials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Treatment With Stereotactic Ablative Radiotherapy for Up to 5 Oligometastases in Patients With Cancer: Primary Toxic Effect Results of the Nonrandomized Phase 2 SABR-5 Clinical Trial. Olson, R., Jiang, W., Liu, M., et al.[2023]

Stereotactic ablative radiotherapy (SABR) has rapidly expanded in clinical use for treating various primary and metastatic tumors, demonstrating promising results in tumor control.

Despite its effectiveness, SABR can lead to serious complications, highlighting the need for strategies to reduce these risks and improve the safety of the treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Serious complications associated with stereotactic ablative radiotherapy and strategies to mitigate the risk. Lo, SS., Sahgal, A., Chang, EL., et al.[2018]

Stereotactic Ablative Radiotherapy (SABR) demonstrated a high local control rate of 90% at one year for treating oligometastatic colorectal cancer patients, with better outcomes for lesions treated with higher doses (≥ 60 Gy).

The treatment was found to be safe, with no cases of radiation-induced liver disease or severe toxicity, making SABR a viable option for patients with inoperable liver or lung metastases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic Ablative Radiotherapy (SABR) in inoperable oligometastatic disease from colorectal cancer: a safe and effective approach. Comito, T., Cozzi, L., Clerici, E., et al.[2022]

Stereotactic ablative radiation therapy (SABR) was found to be effective for treating pulmonary metastases, with a median follow-up of 23 months showing improved overall survival (OS) for patients with 3 or fewer metastases compared to those with more (74.2% vs. 59.3% at 24 months).

Patients with less responsive primary tumors (like adrenal or pancreatic cancers) had higher local failure rates, suggesting that higher doses of SABR or surgical options may be necessary for these cases to improve treatment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic ablative radiation therapy for pulmonary metastases: Improving overall survival and identifying subgroups at high risk of local failure. Pasalic, D., Lu, Y., Betancourt-Cuellar, SL., et al.[2021]

In a study of 85 patients with spine metastases treated with stereotactic ablative radiation therapy (SABR), the treatment demonstrated a 74.1% overall survival rate at two years and a 72.3% local control rate, indicating its efficacy in managing spinal metastases.

SABR was associated with significant pain relief, as 83.3% of patients with pre-treatment pain experienced a complete response, and the treatment showed a favorable safety profile with no severe toxicities reported.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic ablative radiation therapy for spinal metastases: experience at a single Brazilian institution. Marta, GN., de Arruda, FF., Miranda, FA., et al.[2023]

Stereotactic ablative body radiotherapy (SABR) is a feasible and well-tolerated treatment for patients with bone-only oligometastatic breast cancer, with 80% of patients successfully receiving treatment and no severe (grade 3 or 4) toxicities reported.

The treatment showed promising efficacy, with a 100% local progression-free survival (LPFS) and 67% distant progression-free survival (DPFS) at two years, suggesting that SABR could be a viable option for this patient group.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic ablative body radiotherapy (SABR) for bone only oligometastatic breast cancer: A prospective clinical trial. David, S., Tan, J., Savas, P., et al.[2020]

Stereotactic ablative radiotherapy (SABR) shows high effectiveness for oligometastatic breast cancer, achieving local control rates of 97% at 1 year and 90% at 2 years, based on a meta-analysis of 10 studies involving 467 patients.

SABR is associated with a low toxicity rate, with only 4.1% of patients experiencing grade 2 or 3 side effects, indicating it is a safe treatment option for this patient population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stereotactic body radiotherapy to treat breast cancer oligometastases: A systematic review with meta-analysis. Viani, GA., Gouveia, AG., Louie, AV., et al.[2021]

Stereotactic ablative radiotherapy (SABR) is a highly effective and low-toxicity treatment for metastatic tumors, achieving local control rates of about 80%.

SABR shows promise in treating oligometastatic patients, with pilot studies suggesting it may be 'curative' in 20-25% of cases, especially when combined with systemic therapies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

New concepts and insights into the role of radiation therapy in extracranial metastatic disease. Ricardi, U., Filippi, AR., Franco, P.[2013]

Citations

1. pubmed.ncbi.nlm.nih.gov pubmed.ncbi.nlm.nih.gov/38575431/

Treatment Outcomes of Stereotactic Ablative Body ... This study confirmed that SABR was a safe, non-invasive treatment option for patients with extracranial OM and OP diseases originated from primary breast ...

2. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0936655524001092

Treatment Outcomes of Stereotactic Ablative Body ... This study reported SABR treatment outcomes for multisite OM and OP diseases originating from metastatic breast cancer · It showed modest local control and post- ...

3. ascopubs.org ascopubs.org/doi/10.1200/OA-25-00031

A Phase II Prospective Multicenter Trial In this study of 32 patients, nearly half were able to stay on their current treatment without disease progression for at least 6 months, and ...

4. clinicaloncologyonline.net clinicaloncologyonline.net/article/S0936-6555(24)00455-2/fulltext

Stereotactic Ablative Radiotherapy for Bone-Only ... The median time to widespread metastatic disease after SABR was 29 (range, 2–83 months) months and wMFS at 2, 3, and 5 years were 66%, 56%, and ...

5. thegreenjournal.com thegreenjournal.com/article/S0167-8140(21)08752-1/abstract

Stereotactic body radiotherapy to treat breast cancer ... Here we assess the effectiveness and safety of SABR for oligometastatic breast cancer patients by performing a meta-analysis.

6. jamanetwork.com jamanetwork.com/journals/jamaoncology/fullarticle/2773455

Safety and Survival Rates Associated With Ablative ... In this meta-analysis, SABR appeared to be safe and effective in the setting of oligometastatic cancer. Rates of acute and late grade 3 to 5 ...

7. ascopubs.org ascopubs.org/doi/10.1200/JCO.20.00818

Long-Term Results of the SABR-COMET Phase II ... In this long-term report from an international randomized phase II trial, patients who received SABR demonstrated a 22-month improvement in median OS.