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

Trial Summary

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.

What data supports the effectiveness of the drugs used in the APBI vs Endocrine Therapy for Breast Cancer trial?

Research shows that aromatase inhibitors (AIs) like anastrozole, letrozole, and exemestane are more effective than tamoxifen in preventing breast cancer from coming back in postmenopausal women. These drugs have been shown to improve disease-free survival, meaning patients live longer without the cancer returning. ^{1 2 3 4 5}

Is endocrine therapy for breast cancer safe?

Endocrine therapies like tamoxifen and aromatase inhibitors (anastrozole, letrozole, exemestane) are generally considered safe for treating breast cancer, though they can have side effects. Aromatase inhibitors may cause more bone fractures and joint pain compared to tamoxifen, which is associated with more endometrial cancers and blood clots. ^{1 3 5 6 7}

How does the treatment APBI differ from other breast cancer treatments?

APBI (Accelerated Partial Breast Irradiation) is unique because it targets only the part of the breast where the cancer was removed, rather than the whole breast, and is delivered over a shorter period of time. This is different from traditional radiation therapy, which typically involves treating the entire breast over several weeks. ^{2 3 5 6 8}

What is the purpose of this trial?

This trial is testing two treatments for elderly women with low-risk breast cancer: targeted radiation and hormone-blocking medication. The goal is to see which treatment better improves quality of life while effectively controlling the cancer. The study will include women aged 65 and older with small, low-risk tumors. Recent trials have shown advantages in using newer hormone-blocking medications over the older standard treatment.

Research Team

Dana Casey, MD

Principal Investigator

University of North Carolina, Chapel Hill

Eligibility Criteria

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

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

Treatment Details

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.

Participant Groups

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+

Findings from Research

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]

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]

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]

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]

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, 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]

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]

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]

References

1. England pubmed.ncbi.nlm.nih.gov

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

2. Hungary pubmed.ncbi.nlm.nih.gov

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

3. Netherlands pubmed.ncbi.nlm.nih.gov

Aromatase inhibitors in the adjuvant setting: bringing the gold to a standard? [2022]

4. United States pubmed.ncbi.nlm.nih.gov

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

5. United States pubmed.ncbi.nlm.nih.gov

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

6. United States pubmed.ncbi.nlm.nih.gov

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

7. England 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. [2022]

8. United States pubmed.ncbi.nlm.nih.gov

Concurrent or Sequential Hormonal and Radiation Therapy in Breast Cancer: A Literature Review. [2022]