• General condition: Age [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  General condition age will be recorded.
• General condition: performance status at diagnosis [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Performance status by Eastern Cooperative Oncology Group (ECOG) Scale
• General condition and history: substance abuse [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With Substance abuse of tobacco and alcohol will be recorded.
• Diagnosis of other primary tumors [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Diagnosis of other primary tumors synchronous or metachronous, will be recorded.
• Body mass index (BMI) [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  BMI is a value derived from the mass (weight) and height. The BMI is defined as the body mass divided by the square of the body height, and is universally expressed in units of kg/m2, resulting from mass in kilograms and height in metres.
• Primary comorbidities [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Primary comorbidities will be recorded.
• Mutational status of BReast CAncer gene (BRCA) or other genes of genetic predisposition [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Mutational status of BRCA or other genes of genetic predisposition will be recorded.
• Family history of cancer [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Family history of cancer will be recorded.
• Anatomopathological characteristics of the tumor: date of diagnosis [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Date of diagnosis will be collected.
• Anatomopathological characteristics of the tumor: histology [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  The histology of the tumor will be collected
• Anatomopathological characteristics of the tumor: clinical and/or pathological stage [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Tumor clinical and/or pathological stage will be collected through the tumor-node-metastasis (TNM) staging system of the Union for International Cancer Control (UICC).
• Anatomopathological characteristics of the tumor: hormone-receptor expression [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Hormone-receptor expression will be collected
• Anatomopathological characteristics of the tumor: Human Epidermal Growth Factor Receptor 2 (HER-2) expression [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Human Epidermal Growth Factor Receptor 2 (HER-2) expression will be collected
• Anatomopathological characteristics of the tumor: histologic grade [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Tumor histologic grade will be collected
• Anatomopathological characteristics of the tumor: Ki-67 [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Tumor Ki-67 proliferation index will be collected
• Anatomopathological characteristics of the tumor: lymphovascular invasion [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With Presence of lymphovascular invasion will be collected
• Treatment data: date of surgery [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Will be collected date of surgery
• Treatment data: type of surgery [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of participants with each type of surgery: mastectomy or lumpectomy or quadrantectomy or lymphadenectomy or sentinel lymph node biopsy will be collected.
• Treatment data: type of chemotherapy [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With neoadjuvant chemotherapy and adjuvant chemotherapy.
• Treatment data: adjuvant radiotherapy [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With adjuvant radiotherapy
• Treatment data: adjuvant hormonotherapy [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With hormonotherapy
• Treatment data: other type of anti-cancer treatment [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With other type of anti-cancer treatment.
• Follow-up data: relapse type [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With each relapse type: local, regional or distant
• Follow-up data: site of metastatic disease [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With site of metastatic disease
• Follow-up data: occurrence of other primary tumors [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With occurrence of other primary tumors whether or not of breast origin (in situ or invasive).
• Follow-up data: current condition [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  The date of the last review and current clinical condition will be recorded.

• Biological and molecular characteristics analyzed in primary tumors: tumor subtypes [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With tumor subtypes, luminal profiles (e.g., luminal subtypes M1/M2, intrinsic subtypes)
• Biological and molecular characteristics analyzed in primary tumors: risk groups [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With risk groups on the reference of breast cancer in women, including morphological analyses and description of the clinical profile (e.g., morphological type, differentiation (histologic grade), Estrogen Receptor (ER), Progesterone Receptor (PgR), Human Epidermal growth factor Receptor 2 (HER2), Androgen Receptor (AR), Ki-67).
• Date and cause of death [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Date and cause of death, when applicable.
• Disease-free survival (DFS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  DFS: it is defined as the time from date of initial breast cancer diagnosis to the date of the first documented relapse event (local, regional and/or distant) of the disease, second breast or non-breast primary tumor, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered.
• Distant metastasis-free survival (DMFS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  DMFS: it is defined as the time from date of initial breast cancer diagnosis to the date of the first documented distant relapse, second invasive non-breast primary tumor, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered.
• Progression-free survival (PFS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  PFS: it is defined as the time from the start date of a specific treatment to the documentation of disease progression on such treatment, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered.
• Overall survival (OS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  OS: it is defined as the time from the date of initial breast cancer diagnosis to the date of death due to any cause.

• Biological and molecular characteristics analyzed in primary tumors: tumor subtypes [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With tumor subtypes, luminal profiles (e.g., luminal subtypes M1/M2, intrinsic subtypes)
• Biological and molecular characteristics analyzed in primary tumors: risk groups [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Number of Participants With risk groups on the reference of breast cancer in women, including morphological analyses and description of the clinical profile (e.g., morphological type, differentiation (histologic grade), Estrogen Receptor (ER), Progesterone Receptor (PgR), HER2, Androgen Receptor (AR), Ki-67).
• Date and cause of death [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  Date and cause of death, when applicable.
• Disease-free survival (DFS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  DFS: it is defined as the time from date of initial breast cancer diagnosis to the date of the first documented relapse event (local, regional and/or distant) of the disease, second breast or non-breast primary tumor, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered.
• Distant metastasis-free survival (DMFS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  DMFS: it is defined as the time from date of initial breast cancer diagnosis to the date of the first documented distant relapse, second invasive non-breast primary tumor, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered.
• Progression-free survival (PFS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  PFS: it is defined as the time from the start date of a specific treatment to the documentation of disease progression on such treatment, or death due to any cause, whichever occurs first. In the event that none of the previous events were observed, censoring the last contact date will be considered.
• Overall survival (OS). [ Time Frame: From date of patient breast cancer diagnosis until 2017. ]
  OS: it is defined as the time from the date of initial breast cancer diagnosis to the date of death due to any cause.

Inclusion Criteria:

• Male patients diagnosed with primary invasive breast carcinoma between the years 2000-2017, and who have been treated and/or followed up in the Medical Oncology Departments of participating sites.
• The enrollment of patients who died is allowed.

Exclusion Criteria:

• Male patients who do not wish to participate in the study for any reason.