In the Netherlands approximately one out of seven women will develop breast cancer during her life. Most of these breast cancers are early stage, 40% of the women have stage 1. Stage 1 breast cancer means that the cancer is small (size <2cm) and only in the breast tissue or it might be found in lymph nodes close to the breast. The standard treatment for stage 1 breast cancer is breast conserving surgery (BCS), sentinel lymph node procedure (SLNP) and additional radiotherapy. This standard treatment protocol results in a10 years survival rate of 95% for stage 1 disease. However, nowadays there is a discussion whether these early stage breast cancer could be treated less invasively. To reduce the invasiveness of breast cancer treatment, without compromising breast cancer specific survival, minimally invasive ablation procedure of the breast tumor can be an option for small breast lesions.

Patients with a tumor size<2 cm will undergo ultra guided microwave ablation (MWA) with local anesthesia. After a small incision 2-3 millimeters, an MWA electrode is placed at the end of the tumor with ultrasound guidance. The microwaves in MWA create heat around the needle and destroy the cancer cells. There are several advantages of ablation procedures: it is a minimal invasive technique, with a small or absent cutaneous scar and thereby potentially improving patient quality of life. Furthermore, ablative treatment can be done under local anesthesia and/or conscious sedation instead of general anesthesia and in daycare setting, which can reduce treatment cost. A post procedural MRI (after ablation) can determine whether the ablation procedure of the tumor volume is complete. The purpose of this study is to assess whether minimally invasive microwave ablation (MWA) followed by postprocedural MRI scan can be an alternative treatment for breast surgery in early stage breast cancer. Is the quality of life, the cosmetic outcome, fear of breast cancer recurrence, and costs in patient treated with MWA comparable or better compared to patients treated with breast surgery?

Inclusion Criteria:

• age should be 18 years and older
• a solid non-lobular invasive breast tumor with a size <2cm based upon ultrasound and MRI measurements
• without mammographic or MRI evidence of extensive disease
• no involved lymph nodes on ultrasound and MRI scan.

Exclusion Criteria:

• more than one breast tumor,
• (lymph node) metastases
• breast implants
• indication for neoadjuvant chemotherapy.
• pacemaker,
• pregnant
• breastfeeding