UZ/KU Leuven Program for Post-mortem Tissue Donation to Enhance Research

Inclusion Criteria:

• Age ≥ 18 years.

• Signature of informed consent by the subject.

• Metastatic breast cancer, or hereditary cancer syndrome with a moderate to highlifetime risk of breast cancer, for which the patient is treated/followed in UZLeuven or treated in another hospital and referred to UZ Leuven specifically for thetrial.

Additional inclusion criteria for the different substudies:

• Pilot phase: no additional inclusion criteria.

• ILC substudy: histologically confirmed history of ILC.

• IBC substudy: history of IBC, fulfilling the following criteria described by Dawoodet al: rapid onset of breast erythema, oedema and/or peau d'orange and/or warmbreast with or without an underlying palpable mass, duration of history of no morethan 6 months, erythema occupying at least one-third of the breast and pathologicalconfirmation of invasive carcinoma.

• Hereditary cancer syndrome substudy: confirmed presence of a germline mutation knownto be associated with a moderate to high lifetime risk of BC (e.g. known pathogenicvariants in the genes BRCA1/2, CHEK2, TP53, PALB2) and presence of at least onemalignant lesion at time of inclusion (of any origin) .

• Other substudies: no additional inclusion criteria.

Exclusion Criteria:

• Presence of a transmissible disease that can form a risk to the health ofresearchers or others handling the body or patient samples. This includes but is notlimited to the following infectious diseases: human immunodeficiency virus (HIV),active hepatitis C virus (HCV), encephalitis of unknown cause, Creutzfeldt-Jakobdisease, rabies, active malaria, active tuberculosis, active SARS-CoV-2 infection.

• Presence of any factors that could logistically or organizationally impede the studyor the performance of sampling within a reasonable post-mortem time frame. Thisincludes but is not limited to: residence of the subject at a faraway distance fromthe UZ Leuven hospital; residence of the subject on territory outside of Belgium;impossibility to notify the clinician confirming the death and the researcherswithin a reasonable time frame in case of death.

Additional exclusion criteria for the different substudies:

• ILC substudy, IBC substudy: diagnosis of a malignancy other than breast cancer inthe 5 years prior to inclusion. Exceptions include basal cell carcinoma of the skinor squamous cell carcinoma of the skin and in situ cervical carcinoma.