APBI vs Endocrine Therapy for Breast Cancer

(CAMERAN Trial)

Overseen By Lori Stravers

Age: 65+

Sex: Female

Trial Phase: Phase 2

Sponsor: UNC Lineberger Comprehensive Cancer Center

Must not be taking: Anti-hormonal agents

Disqualifiers: Chemotherapy, Multifocal tumor, Metastases, others

Stay on Your Current Meds You can continue your current medications while participating

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

Prior Safety Data This treatment has passed at least one previous human trial

Compensation: Varies

Number of Visits: Unknown

Duration: 5 fractions for APBI; up to 5 years for endocrine therapy

90 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial compares two treatments for elderly women who have undergone a lumpectomy for low-risk breast cancer. It examines the effects of accelerated partial breast irradiation (APBI) and endocrine therapy, such as hormone-blocking medications, on quality of life and cancer control. APBI consists of a short series of radiation sessions targeted at the breast surgery site, while endocrine therapy involves taking medication for about five years. Women with a small breast tumor (less than 2 cm) with certain favorable characteristics and no lymph node involvement may be suitable candidates. The trial aims to determine which treatment offers a better quality of life while effectively controlling cancer. As a Phase 2 trial, this research measures the treatment's effectiveness in an initial, smaller group, allowing participants to contribute to important findings.

Will I have to stop taking my current medications?

If you are currently taking anti-hormonal agents or hormone replacement therapy, you will need to stop them at least 30 days before joining the trial. Other medications are not specifically mentioned, so it's best to discuss with the trial team.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research shows that accelerated partial breast irradiation (APBI) is generally manageable for patients with early breast cancer. Studies have found that APBI causes fewer and milder side effects than standard radiation treatments. Patients report maintaining a good quality of life, indicating that the treatment is gentler on the body.

For hormone therapy, which includes drugs like tamoxifen and anastrozole, extensive safety information is available. These drugs are commonly used for breast cancer and have FDA approval. While some patients may experience side effects like hot flashes or joint pain, many manage the treatment well over time.

Both treatment options in this study appear safe, with manageable side effects. Evidence suggests that patients in this trial can expect a treatment experience that is mostly comfortable and aligns with their quality of life goals. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about these treatments because they offer different approaches to tackling breast cancer. Accelerated Partial Breast Irradiation (APBI) is unique because it delivers radiation directly to the lumpectomy cavity in just five sessions every other day, potentially reducing overall treatment time and minimizing exposure to surrounding healthy tissue. On the other hand, the endocrine therapies like Tamoxifen, Anastrozole, Exemestane, Letrozole, Fulvestrant, and Toremifene work by interfering with hormone activity that fuels cancer growth, offering a non-invasive approach with long-term management over five years. These diverse treatment strategies provide patients with options that could be tailored to their specific needs and conditions.

What evidence suggests that this trial's treatments could be effective for low-risk elderly breast cancer patients?

This trial will compare Accelerated Partial Breast Irradiation (APBI) with Endocrine Therapy for breast cancer. Research has shown that APBI is a promising treatment, with studies finding a breast cancer-specific survival rate of 99.6%. Although there is no significant difference in overall survival compared to whole breast radiotherapy, APBI patients face a slightly higher chance of cancer returning in the same area. In terms of quality of life, patients treated with APBI report outcomes similar to those receiving other common treatments.

For the Endocrine Therapy arm, which includes drugs like Tamoxifen and Anastrozole, research has shown these treatments effectively reduce the risk of breast cancer recurrence by blocking hormones that can help cancer grow. Each drug has its own side effects, but they are generally well-tolerated over time. Both treatments in this trial aim to manage the disease effectively and improve patients' quality of life. ^{3 5 6 7 8}

Who Is on the Research Team?

Dana Casey, MD

Principal Investigator

University of North Carolina, Chapel Hill

Are You a Good Fit for This Trial?

This trial is for women over 65 with early-stage, low-risk breast cancer (small tumors under 2cm, not aggressive, and no spread to lymph nodes). Participants should be healthy enough for hormone therapy or radiation and have a positive hormone receptor status. They must not have other cancers that could affect the study or serious uncontrolled medical conditions.

Inclusion Criteria

My cancer is at an early stage (grade 1 or 2).

My doctor thinks I am a good candidate for a specific type of targeted breast radiation.

There is no spread of cancer into the lymphovascular space.

Exclusion Criteria

I have cancer in both breasts at the same time.

I have stopped my hormonal replacement therapy at least 30 days ago.

I have an autoimmune disease that increases my risk during radiation.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive either accelerated partial breast irradiation (APBI) consisting of 5 fractions of radiation therapy delivered every other day or endocrine therapy chosen by the treating medical oncologist with an aim of 5 years duration.

5 fractions for APBI; up to 5 years for endocrine therapy

Follow-up

Participants are monitored for quality of life and oncologic outcomes, with primary assessments at 1 year and additional monitoring for overall survival and disease-free survival up to 5 years.

5 years

What Are the Treatments Tested in This Trial?

Interventions

• Accelerated Partial Breast Irradiation (APBI)
• Tamoxifen, Anastrozole, Exemestane, Letrozole, Fulvestrant, Toremifene

Trial Overview The CAMERAN study compares two treatments after lumpectomy in older women with low-risk breast cancer: one group receives accelerated partial breast irradiation (APBI) alone, while another gets endocrine therapy alone. The goal is to see which treatment offers better quality of life without compromising disease control.

How Is the Trial Designed?

Group I: Accelerated Partial Breast Irradiation (APBI) Experimental Treatment 1 Intervention

APBI will consist of 5 fractions of radiation therapy delivered every other day to the lumpectomy cavity.

Group II: Endocrine Therapy Active Control 1 Intervention

Endocrine therapy will be chosen by the treating medical oncologist with an aim of 5 years duration, as tolerated by the patient.

Accelerated Partial Breast Irradiation (APBI) is already approved in United States, European Union, Canada for the following indications:

Approved in United States as Accelerated Partial Breast Irradiation for:

• Early-stage breast cancer
• Ductal carcinoma in situ (DCIS)
• Stage I or II breast cancer

Approved in European Union as Accelerated Partial Breast Irradiation for:

• Early-stage breast cancer
• Ductal carcinoma in situ (DCIS)
• Stage I or II breast cancer

Approved in Canada as Accelerated Partial Breast Irradiation for:

• Early-stage breast cancer
• Ductal carcinoma in situ (DCIS)
• Stage I or II breast cancer

Who Is Running the Clinical Trial?

UNC Lineberger Comprehensive Cancer Center

Lead Sponsor

Trials

377

Recruited

95,900+

Published Research Related to This Trial

A review of seven studies involving adjuvant hormonal therapy in ER/PR positive breast cancer found no significant difference in survival or local-regional recurrence between concurrent and sequential treatment with radiation.

While both treatment approaches yielded similar disease outcomes, concurrent therapy was associated with a higher risk of breast and lung fibrosis, suggesting that sequential therapy may be a safer option.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Concurrent or Sequential Hormonal and Radiation Therapy in Breast Cancer: A Literature Review. Cecchini, MJ., Yu, E., Potvin, K., et al.[2022]

Aromatase inhibitors (AIs) like anastrozole, letrozole, and exemestane are effective adjuvant therapies for postmenopausal women with hormone receptor-positive invasive breast cancer, showing similar overall survival rates compared to tamoxifen.

While AIs have acceptable toxicity profiles with fewer endometrial cancers and thromboembolic events, they are associated with a higher risk of bone fractures and joint pain compared to tamoxifen.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adjuvant endocrine therapy in hormone receptor-positive postmenopausal breast cancer: evolution of NCCN, ASCO, and St Gallen recommendations. Carlson, RW., Hudis, CA., Pritchard, KI.[2019]

Aromatase inhibitors (AIs) like anastrozole and letrozole are now approved as first-line treatments for postmenopausal women with estrogen receptor-positive metastatic breast cancer, showing significant efficacy compared to the previously used tamoxifen.

Ongoing clinical trials are exploring various strategies for using AIs, including direct comparisons with tamoxifen, extending AI treatment after tamoxifen, and sequencing therapies, which will help determine the best treatment approaches for improving patient outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Emerging role of aromatase inhibitors in the adjuvant setting. Goss, PE.[2019]

In a study of 3887 post-menopausal patients with hormone receptor-positive early breast cancer, over 85% persisted with letrozole treatment for 12 months, but 14.6% discontinued, primarily due to side effects.

Musculoskeletal symptoms and sleep disorders were the most significant adverse events leading to treatment discontinuation, with hazard ratios of 2.55 and 1.95, respectively, indicating a strong need for targeted compliance programs to support patients experiencing these issues.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of side-effects on early therapy persistence with letrozole in post-menopausal patients with early breast cancer: Results of the prospective EvAluate-TM study. Nabieva, N., Fehm, T., Häberle, L., et al.[2022]

Third-generation aromatase inhibitors (AIs) like anastrozole, letrozole, and exemestane have emerged as effective alternatives to tamoxifen for treating postmenopausal breast cancer, particularly in hormone receptor-positive cases, as shown in the ATAC trial with over five years of follow-up.

Fulvestrant, a new type of estrogen receptor antagonist with no partial agonist activity, represents a promising option in breast cancer treatment, and the review discusses future sequencing strategies for using AIs earlier in treatment regimens.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

New developments in the treatment of postmenopausal breast cancer. Howell, A.[2018]

Aromatase inhibitors (AIs) like anastrozole, exemestane, and letrozole provide longer disease-free survival (DFS) compared to tamoxifen for women with early breast cancer, based on a review of multiple trials.

AIs are well tolerated and have a different safety profile than tamoxifen, making them a favorable option for initial adjuvant therapy or as a switch from tamoxifen after 2-3 years, especially for node-positive patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Choosing early adjuvant therapy for postmenopausal women with hormone-sensitive breast cancer: aromatase inhibitors versus tamoxifen. Carpenter, R.[2018]

The use of adjuvant endocrine therapy, particularly aromatase inhibitors (AIs) like anastrozole, has significantly improved disease-free survival rates in post-menopausal women with breast cancer compared to the traditional treatment with tamoxifen.

Switching from tamoxifen to an AI, such as letrozole or exemestane, after a few years has shown impressive reductions in the risk of cancer recurrence, highlighting the evolving treatment strategies for advanced breast cancer.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Aromatase inhibitors in the adjuvant setting: bringing the gold to a standard? Clemons, M., Coleman, RE., Verma, S.[2022]

Adjuvant endocrine therapy for hormone-sensitive early breast cancer in postmenopausal women should include an aromatase inhibitor (AI) like anastrozole or letrozole for 5 years, as supported by major clinical trials such as ATAC and BIG 1-98.

Alternatives like sequential therapy with tamoxifen followed by an AI, or extending letrozole treatment after tamoxifen, have shown significant improvements in patient outcomes, particularly in those with node-positive disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Adjuvant endocrine therapy in postmenopausal hormone-sensitive breast cancer: to start, to switch or to extend?]. Nagykálnai, T.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6378667/

Effectiveness of different accelerated partial breast ... This systematic review was conducted to compare the effectiveness of different accelerated partial breast irradiation (APBI) techniques for the treatment of ...

2. sciencedirect.com sciencedirect.com/science/article/pii/S096097762500476X

Long-term outcomes of three distinct once-daily schedules ... Once-daily accelerated partial breast irradiation is feasible. Long term outcomes are comparable with whole breast radiotherapy. Shorter schedule (<5 fractions ...

3. advancesradonc.org advancesradonc.org/article/S2452-1094(25)00079-X/fulltext

Long-Term Outcomes of Multimodality Accelerated Partial ... Breast cancer–specific survival (BCSS) was 99.6% at the time of analysis. There was no statistically significant difference in overall survival or recurrence ...

4. ro-journal.biomedcentral.com ro-journal.biomedcentral.com/articles/10.1186/s13014-021-01752-2

A meta-analysis of the efficacy and safety of accelerated ... The analysis showed that patients receiving APBI had a higher local recurrence rate, but no differences in distant metastasis, breast cancer ...

5. nature.com nature.com/articles/s41598-025-85342-2

Quality of life in early breast cancer patients after adjuvant ... Early BC patients treated with APBI showed non-inferior short-term and late HRQoL outcomes compared to hypo-WBI. In addition to previous ...

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC6411019/

External Beam Accelerated Partial Breast Irradiation The aim of the study was to evaluate and compare four different external beam radiotherapy techniques of accelerated partial breast irradiation (APBI)

7. ro-journal.biomedcentral.com ro-journal.biomedcentral.com/articles/10.1186/s13014-024-02412-x

Toxicity of external beam accelerated partial-breast irradiation ... External APBI demonstrated better feasibility and less toxicity than the standard regimen in the adjuvant setting for treating early breast cancer patients.

8. sciencedirect.com sciencedirect.com/science/article/abs/pii/S1879850023002886

Early and Intermediate Treatment Outcome After ... The use of once daily external beam APBI with 26 to 28 Gy/5f/1w in patients with early breast cancer resulted in excellent treatment tolerance and high disease ...