Study was stopped in agreement with investigator due to slow recruitment.

Thermotherapy is a technology aiming at destroying tissue, for example tumor tissue. Immunostimulating Interstitial Laser Thermotherapy (imILT) is a specific form of thermotherapy, which, in addition to destroying tumor tissue, has been optimized to cause a tumor specific immunologic response. In laboratory animals the imILT method has also been shown to induce a so called abscopal effect. This means that when one tumor is treated with imILT other, untreated, tumors also decrease in size. The immunologic response has previously been characterized in breast cancer patients after receiving imILT treatment , and presumed abscopal effects induced by imILT have also been described in a malignant melanoma patient.

The purpose of this trial is to investigate the functionality and safety of the imILT treatment method in patients diagnosed with breast cancer.

The treatment method has successfully been used for treatment of patients with breast cancer and malignant melanoma. Treatment of breast cancer patients caused an increase of cytotoxic T lymphocytes in the treated tumor, as well as activated dendritic cells at the tumor border. Regulatory T lymphocytes decreased in the regional lymph nodes.

This trial is explorative, prospective, open and non-randomized. Five breast cancer patients will be treated in this trial, which is estimated to be carried out during a time period of 9 months.

Inclusion Criteria:

1. Have histologically confirmed breast cancer
2. Hormone receptor positive or negative
3. Have assessable tumour by MRI or ultrasound
4. Are patients deemed unfit for surgical excision of tumour under general anaesthetic.
5. Have been given informed verbal and written consent for participation in the trial
6. Have stable hematologic, renal and hepatic functions.

Exclusion Criteria:

1. Are known to be HIV positive
2. Have active autoimmune disease
3. Are on corticosteroid medication
4. Have evidence of bleeding diathesis or coagulopathy.