Study to assess the capability of physicians (breast surgeons and pathologists) to recognize breast cancer in images of fresh lumpectomies generated with the Histolog Scanner, a recent large field-of-view confocal laser scanning medical imaging device.

Breast cancer is the commonest cancer in female worldwide and breast-conserving surgery (BCS) became the most frequently performed surgical treatment for women with early-stage breast cancer. The ability to identify subclinical and deep-seated tumor during BCS is still difficult, and the surgeon must rely on nonspecific visual changes and manual palpation of subtle irregularities to guide cancer excision. Although there is no consensus on negative surgical margins, at least 20 % of patients undergo more than one procedure to achieve acceptable margins as part of breast-conserving strategy. The development of reliable intraoperative assessment tools which can provide a timely indication of whether re-excision in tumor bed after BCS is indicated at the time of primary surgery would be an asset. The Histolog Scanner is a recent confocal microscope designed for fresh tissue ex-vivo medical imaging with high resolution and speed to guide intraoperative assessment and offer support in clinical decision making. Allowing the quickest and most effective intraoperative assessment of breast surgical specimen regardless of center clinical workflow and intraoperative availability of pathologist, is the aim of this international study. The main objective is to demonstrate that both pathologists and surgeons are able to detect breast cancer tissues in Histolog Scanner images of breast surgical specimens.

Fresh Breast surgical specimens with breast cancer (invasive or in-situ) will be imaged with the Histolog Scanner prior Standard-of-Care final assessment in pathology. Content of the images will be reviewed by a board of expert pathologists using the gold standard (H&E-stained images) as reference. Blind assessment of the breast cancer content of these Histolog Scanner images will be realized by breast surgeons and pathologist.

Inclusion Criteria:

• Adult female patient ≥18 years old
• Women with diagnosed, operable invasive or in situ ductal carcinoma, invasive lobular carcinoma who are deemed breast surgery candidates (i.e. lumpectomy or mastectomy).
• Patient able to read, understand and give informed consent

Exclusion Criteria:

• Patient not informed
• Patient previously treated for breast carcinoma
• Patient has undergone presurgical neo-adjuvant treatment
• Patient is pregnant/lactating
• Patient is male
• Participation in any other clinical study that would affect data acquisition

Patient are selected by breast surgeons during their standard-of-care preoperative consultations