An Observational Study on Human Epidermal Growth Factor Receptor (HER) 2 Status of Breast Invasive Carcinoma in Latin American Participants

Breast Cancer Participants

Breast tissue samples from female participants with a breast cancer diagnosis that undergo an anatomopathological examination of surgical specimens and/or core needle biopsies will be considered for analysis in this study.

Percentage of Participants With Human Epidermal Growth Factor Receptor 2 (HER2) Status in Breast Cancer Specimens Using Immunohistochemistry (IHC) and Silver In-Situ Hybridization (SISH) Procedures

HER2 status of the collected tissue samples was determined based on the results obtained from IHC test and SISH procedure. The IHC test gives a score of 0 to 3 positive (+) that measures the amount of HER2 receptor protein on the surface of cells in a breast cancer tissue sample. If the score is 0 to 1+, it's called "HER2 negative (-)." If the score is 2+, it's called "borderline." A score of 3+ is called "HER2 positive." Tissue samples which had the IHC score of 2+ (borderline) were re-tested using SISH procedure for confirmation of the HER2 status. Tissue samples with SISH test results + were considered as HER2+. Tissue samples for which HER2 status was not determined were considered as HER2 equivocal.

Percentage of Participants With Different Phenotypes of Breast Cancer

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were estrogen receptor (ER) + and/or progesterone receptor (PR) +, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2. Histological grading was done by Nottingham Histologic Score system based on three factors, a) the amount of gland formation (differentiation), b) the nuclear features (pleomorphism) and c) the mitotic activity. Each of these features is scored from 1-3, and then each score is added to give a final total score ranging from 3-9. The final total score is used to determine the grade in the following way: i) Grade 1 tumors have a score of 3-5, ii) Grade 2 tumors have a score of 6-7, and iii) Grade 3 tumors have a score of 8-9.

Percentage of Participants With Histological Sub-types of Breast Cancer

Histological subtypes of breast cancer included ductal carcinoma, lobular carcinoma, mucinous carcinoma, mixed carcinoma, metaplastic carcinoma, and others.

Percentage of Participants With ER Status (Positive or Negative) Across Different Age Groups

Participants were categorized in to following age groups: a) less than (<) 40 years, b) 40-49 years, c) 50-59 years, d) 60-69 years, e) greater than or equal to (≥) 70 years.

Percentage of Participants With ER Status (Positive or Negative) Based on Nuclear Grades

Nuclear pleomorphism was observed and graded accordingly. Grade 1: Nuclei small with little increase in size in comparison with normal breast epithelial cells, regular outlines, uniform nuclear chromatin, little variation in size; Grade 2: Cells larger than normal with open vesicular nuclei, visible nucleoli, and moderate variability in both size and shape; Grade 3: Vesicular nuclei, often with prominent nucleoli, exhibiting marked variation in size and shape, occasionally with very large and bizarre forms.

Percentage of Participants With ER Status (Positive or Negative) Based on Lymphovascular Invasion

Lymphovascular invasion is entering of breast cancer cells in to the lymph or vascular/blood channels.

Percentage of Participants With PR Status (Positive or Negative) Across Different Age Groups

Participants were categorized in to following age groups: a) <40 years, b) 40-49 years, c) 50-59 years, d) 60-69 years, e) ≥70 years.

Percentage of Participants With PR Status (Positive or Negative) Based on Nuclear Grades

Nuclear pleomorphism was observed and graded accordingly. Grade 1: Nuclei small with little increase in size in comparison with normal breast epithelial cells, regular outlines, uniform nuclear chromatin, little variation in size; Grade 2: Cells larger than normal with open vesicular nuclei, visible nucleoli, and moderate variability in both size and shape; Grade 3: Vesicular nuclei, often with prominent nucleoli, exhibiting marked variation in size and shape, occasionally with very large and bizarre forms.

Percentage of Participants With PR Status (Positive or Negative) Based on Lymphovascular Invasion

Lymphovascular invasion is entering of breast cancer cells in to the lymph or vascular/blood channels.

Percentage of Participants With HER2 Status (Positive or Negative) Across Different Age Groups

Participants were categorized in to following age groups: a) <40 years, b) 40-49 years, c) 50-59 years, d) 60-69 years, e) ≥70 years.

Percentage of Participants With HER2 Status (Positive or Negative) Based on Nuclear Grades

Nuclear pleomorphism was observed and graded accordingly. Grade 1: Nuclei small with little increase in size in comparison with normal breast epithelial cells, regular outlines, uniform nuclear chromatin, little variation in size; Grade 2: Cells larger than normal with open vesicular nuclei, visible nucleoli, and moderate variability in both size and shape; Grade 3: Vesicular nuclei, often with prominent nucleoli, exhibiting marked variation in size and shape, occasionally with very large and bizarre forms.

Percentage of Participants With HER2 Status (Positive or Negative) Based on Lymphovascular Invasion

Lymphovascular invasion is entering of breast cancer cells in to the lymph or blood/vascular channels.

Percentage of Participants With Different Phenotypes of Breast Cancer Across Different Age Groups

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2. Participants were categorized in to following age groups: a) <40 years, b) 40-49 years, c) 50-59 years, d) 60-69 years, e) ≥70 years.

Percentage of Participants With Different Phenotypes of Breast Cancer Based on Nuclear Grades

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2. Nuclear pleomorphism was observed and graded accordingly. Grade 1: Nuclei small with little increase in size in comparison with normal breast epithelial cells, regular outlines, uniform nuclear chromatin, little variation in size; Grade 2: Cells larger than normal with open vesicular nuclei, visible nucleoli, and moderate variability in both size and shape; Grade 3: Vesicular nuclei, often with prominent nucleoli, exhibiting marked variation in size and shape, occasionally with very large and bizarre forms.

Percentage of Participants With Different Phenotypes of Breast Cancer Based on Lymphovascular Invasion

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2. Lymphovascular invasion is entering of breast cancer cells in to the lymph or vascular/blood channels.

Percentage of Participants With Different Phenotypes of Breast Cancer Based on ER Status

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2.

Percentage of Participants With Different Phenotypes of Breast Cancer Based on PR Status

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2.

Percentage of Participants With Different Phenotypes of Breast Cancer Based on HER2 Status

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2.

Percentage of Participants With Breast Cancer Phenotypes Among Different Hispanic Countries

Breast cancer phenotypes were classified in to a) Luminal A: tissue samples that were ER+ and/or PR+, HER2-, and either histologic grade 1 or 2; b) Luminal B: tissue samples that were ER+ and/or PR+ and HER2+ or ER+ and/or PR+ and HER2- and histologic grade 3; c) HER2 enriched: tissue samples that were ER-, PR-, and HER2+; d) Triple negative: tissue samples that were negative for ER, PR, and HER2.