Minimal Invasive Axillary Staging and Treatment After Neoadjuvant Systemic Therapy in Node Positive Breast Cancer

Study Overview
=================
Brief Summary
-----------------
Today, the majority of clinically node positive (cN+) breast cancer patients is treated with neoadjuvant systemic therapy (NST). Axillary staging and treatment after NST in cN+ patients are areas of controversy. Patients with a pathological complete response (pCR) of the axillary lymph nodes are not expected to benefit from axillary lymph node dissection (ALND). Hence, less invasive axillary staging procedures are being introduced to avoid unnecessary ALND. However, evidence supporting the safety of replacing ALND by less invasive techniques in terms of oncologic safety and impact on quality of life (QoL) is lacking.

Detailed Description
-----------------
The MINIMAX is a multicenter registry study that includes node positive breast cancer patients, who are treated with NST (chemotherapy and ± immunotherapy), in order to gain insight in the oncologic safety and impact on QoL of less and more invasive axillary staging and treatment strategies. Patients who are included in this study will complete Patient Reported Outcome Measures (PROMs) at baseline (time of diagnosis), and 1 and 5 years after diagnosis to assess impact on QoL. A database will be built by the Netherlands Cancer Registry. Data on patient-, tumor-, pre-NST staging-, post-NST staging- and treatment-characteristics will be retrieved from patients' records by trained data registrars of the Netherlands Comprehensive Cancer Organisation (IKNL) using electronic case report forms (eCRFs). Five-year survival and recurrence will be evaluated to determine oncologic safety. The results will be incorporated in the national guidelines. In case of an equilibrium between less and more invasive strategies, the data of this study will at least be extremely suitable to be used in the shared decision making process.

Official Title
-----------------
Minimal Invasive Axillary Staging and Treatment After Neoadjuvant Systemic Therapy in Node Positive Breast Cancer (MINIMAX): a Dutch Multicenter Observational Study to Gain Insight in Less and More Invasive Axillary Staging and Treatment in Relation to Oncologic Safety and Quality of Life to Develop Evidence-based Guidelines.

Conditions
-----------------
Breast Cancer, Neoadjuvant Therapy, Lymph Node Metastases

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Female patient with unilateral invasive breast cancer and cN1-3 Pathologically proven positive axillary lymph node Planned to undergo neoadjuvant chemotherapy (± immunotherapy), followed by staging and treatment of the breast and axilla Exclusion Criteria: Clinically node negative breast cancer before NST Bilateral invasive breast cancer Neoadjuvant endocrine therapy Distant metastases (including oligometastatic disease) History of invasive breast cancer Other malignancies, except for basal/squamous cell skin cancer, and in situ carcinoma of the cervix or breast Axillary surgery or radiotherapy before NST (this includes SLNB prior to NST)

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------
What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Disease free survival (DFS) | DFS is defined as the time interval between the date of diagnosis until the date that a patient survives without any signs or symptoms of the disease. | 5 years | 
| Breast cancer specific survival (BCSS) | BCSS is defined as the time interval between the date of diagnosis until death from the disease. | 5 years | 
| Overall survival (OS) | OS is defined as the time interval between the date of diagnosis until death from any cause. | 5 years | 
| Axillary recurrence rate (ARR) | ARR is defined as tumor recurrence and as residual tumor that became clinically apparent in the ipsilateral axillary lymph nodes (pathologically proven). | 5 years | 
| Quality of life, as measured by EQ-5D-5L | The EQ-5D-5L comprises a descriptive system questionnaire and a visual analogue scale (VAS). The descriptive system consists of five dimensions: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. For each dimension, participants choose one of 5 levels that best describes their health on that day (from 'no problem'= 1 to 'unable/extreme'= 5). The numbers chosen for the five dimensions are combined to give a 5 digit score (minimum score = 11111 maximum score = 55555). The VAS provides participant's rating of their health on a scale from 0 ('the worst health you can imagine') to 100 ('the best health you can imagine'). | Baseline, and 1 and 5 years after baseline | 
| Quality of life, as measured by Quality of Life Questionnaire Core 30 Items (QLQ-C30) and QLQ-BR23 | These questionnaires contain functional domains, global health status, and symptom scales. For functional domains and global health status, scores range from 0 to 100 with higher scores representing a better level of functioning. For symptoms scales, scores range from 0 to 100 with higher scores representing a greater degree of symptoms. | Baseline, and 1 and 5 years after baseline | 
| Quality of life, as measured by BREAST-Q, which includes the following domains: satisfaction with breasts, psychosocial well being, physical well being, sexual well being. | All domains are scored 0 to 100 points. Higher points represent a better outcome. | Baseline, and 1 and 5 years after baseline |