Breast Cancer, Early-Stage Invasive Breast Carcinoma
Conditions
Keywords
Partial breast irradiation, Whole breast irradiation, Breast-conserving surgery, Sentinel lymph node biopsy omission, Radiotherapy de-escalation, Clinically node-negative breast cancer, Axillary radiation dose
Brief summary
This prospective, multicenter observational cohort study evaluates long-term outcomes in patients with early-stage invasive breast cancer who undergo breast-conserving surgery without sentinel lymph node biopsy or other axillary surgery and subsequently receive adjuvant radiotherapy. The study will evaluate recurrence, survival, radiotherapy-related toxicities, and quality of life. Radiotherapy will be delivered according to routine clinical practice at each participating institution without protocol-mandated treatment assignment. Detailed radiotherapy characteristics, including treatment volume, technique, dose and fractionation, tumor-bed boost, and radiation dose to axillary lymph node levels I-III, will be prospectively collected to evaluate their associations with clinical outcomes.
Detailed description
Recent clinical trials have supported the omission of sentinel lymph node biopsy in selected patients with clinically node-negative early breast cancer. However, radiotherapy approaches after sentinel lymph node biopsy omission vary in routine clinical practice, and prospective data regarding the relationship between radiotherapy characteristics, radiation dose delivered to the axillary lymph nodes, and long-term clinical outcomes remain limited. Depending on patient and tumor characteristics and institutional practice, radiotherapy may include whole-breast or partial-breast irradiation with different treatment techniques, dose-fractionation schedules, and tumor-bed boost strategies. The APROOB Cohort is designed to prospectively characterize these variations and evaluate their associations with recurrence, survival, treatment-related toxicity, and quality of life following omission of sentinel lymph node biopsy. No radiotherapy technique, treatment volume, dose, or fractionation schedule is assigned by the study.
Interventions
RADIATIONAdjuvant Breast Radiotherapy
Adjuvant radiotherapy is delivered after breast-conserving surgery according to routine clinical practice at each participating institution. Radiotherapy may include whole-breast irradiation or partial-breast irradiation, with treatment technique, dose, fractionation, and tumor-bed boost determined by the treating physician. The study does not assign or mandate a specific radiotherapy regimen.
Sponsors
Samsung Medical Center
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
19 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Female patients aged 19 years or older with histologically confirmed invasive breast cancer * Patients who have undergone breast-conserving surgery with curative intent * Patients who did not undergo axillary lymph node surgery, including sentinel lymph node biopsy, at the time of breast cancer surgery * No evidence of distant metastasis on clinical and imaging evaluation before surgery * Planned to receive adjuvant radiotherapy after breast-conserving surgery * Ability and willingness to provide written informed consent before study participation
Exclusion criteria
* Patients initially diagnosed with breast carcinoma in situ before surgery who did not undergo sentinel lymph node biopsy but were subsequently found to have invasive breast cancer on final surgical pathology * Receipt of neoadjuvant systemic therapy before breast cancer surgery * History of a malignancy other than breast cancer within 5 years before study enrollment, except adequately treated non-melanoma skin cancer or carcinoma in situ other than breast carcinoma in situ * Recurrent breast cancer * Bilateral breast cancer or inflammatory breast cancer * Prior radiotherapy to the ipsilateral breast or chest region * Patients considered by the investigator to be unsuitable for study participation or long-term follow-up
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 5-Year Recurrence-Free Survival Rate | From study enrollment to 5 years | Recurrence-free survival is defined as the time from study enrollment to the first occurrence of ipsilateral invasive breast recurrence, ipsilateral regional lymph node recurrence, distant metastasis, or breast cancer death. The 5-year recurrence-free survival rate will be estimated using the Kaplan-Meier method. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 5-Year Axillary Recurrence Rate | From study enrollment to 5 years | Axillary recurrence is defined as newly diagnosed breast cancer recurrence in the ipsilateral axillary lymph nodes after study enrollment. The 5-year cumulative incidence of axillary recurrence will be estimated. |
| 5-Year Locoregional Recurrence Rate | From study enrollment to 5 years | Locoregional recurrence is defined as the first occurrence of one or more of the following after study enrollment: ipsilateral invasive breast recurrence; ipsilateral axillary lymph node recurrence; ipsilateral supraclavicular or infraclavicular lymph node recurrence; or ipsilateral internal mammary lymph node recurrence. The 5-year cumulative incidence will be estimated. |
| 5-Year Distant Metastasis Rate | From study enrollment to 5 years | Distant metastasis is defined as breast cancer metastasis occurring in organs or non-regional lymph nodes outside the ipsilateral breast and ipsilateral regional lymph node regions. The 5-year cumulative incidence of the first distant metastasis after study enrollment will be estimated |
| 5-Year Overall Survival Rate | From study enrollment to 5 years | Overall survival is defined as the time from study enrollment to death from any cause. The 5-year overall survival rate will be estimated using the Kaplan-Meier method. |
| Incidence of Acute Grade 2 or Higher Radiotherapy-Related Toxicity | From the start of radiotherapy through 90 days after completion of radiotherapy | The proportion of participants experiencing at least one grade 2 or higher acute radiotherapy-related adverse event will be assessed using the Common Terminology Criteria for Adverse Events (CTCAE), version 6.0. CTCAE grades range from 1 to 5, with higher grades indicating greater severity. Acute toxicity is defined as toxicity occurring from the start of radiotherapy through 90 days after completion of radiotherapy. |
| Incidence of Late Grade 2 or Higher Radiotherapy-Related Toxicity | From more than 90 days after completion of radiotherapy to 5 years after radiotherapy | The proportion of participants experiencing at least one grade 2 or higher late radiotherapy-related adverse event will be assessed using the Common Terminology Criteria for Adverse Events (CTCAE), version 6.0. CTCAE grades range from 1 to 5, with higher grades indicating greater severity. Late toxicity is defined as toxicity newly occurring or persisting more than 90 days after completion of radiotherapy. |
| Change From Baseline in Global Health Status/Quality of Life Score Assessed by the EORTC QLQ-C30 | Baseline and up to 5 years after radiotherapy | Global health status and quality of life will be assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30). The Global Health Status/Quality of Life scale is transformed to a score ranging from 0 to 100. A higher score indicates better global health status and quality of life. The change from baseline will be evaluated at each scheduled follow-up assessment. |
| Change From Baseline in Breast Symptoms Score Assessed by the EORTC QLQ-BR23 | Baseline and up to 5 years after radiotherapy | Breast symptoms will be assessed using the Breast Symptoms scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Breast Cancer Module 23 (EORTC QLQ-BR23). The score is transformed to a scale ranging from 0 to 100. A higher score indicates more severe breast symptoms and therefore a worse outcome. The change from baseline will be evaluated at each scheduled follow-up assessment. |
| Change From Baseline in Arm Symptoms Score Assessed by the EORTC QLQ-BR23 | Baseline and up to 5 years after radiotherapy | Arm symptoms will be assessed using the Arm Symptoms scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Breast Cancer Module 23 (EORTC QLQ-BR23). The score is transformed to a scale ranging from 0 to 100. A higher score indicates more severe arm symptoms and therefore a worse outcome. The change from baseline will be evaluated at each scheduled follow-up assessment. |
| Change From Baseline in Body Image Score Assessed by the EORTC QLQ-BR23 | Baseline and up to 5 years after radiotherapy | Body image will be assessed using the Body Image scale of the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Breast Cancer Module 23 (EORTC QLQ-BR23). The score is transformed to a scale ranging from 0 to 100. A higher score indicates better body image and therefore a better outcome. The change from baseline will be evaluated at each scheduled follow-up assessment. |
Countries
South Korea
Contacts
CONTACTHaeyoung Kim
Outcome results
None listed