Breast Cancer Overview

Which subtype of breast cancer is characterized by both ER and PR negative status along with Her2 positivity?

What is the common feature of BCL2 across all breast cancer subtypes?

Which therapy is indicated for PD-L1 positive breast cancer?

Which subtype has a low score for both ER and PR, and is characterized as basal type?

What is the primary characteristic that subdivides Her2 low tumors?

What constitutes the triple assessment for breast cancer diagnosis?

Which immunohistochemistry markers are routinely tested for hormone receptor status in breast cancer?

What is Ductal Carcinoma In-Situ (DCIS) characterized by?

What genetic alteration is associated with Secretory Carcinoma?

Which characteristic is NOT associated with Tall Cell Carcinoma with Reversed Polarity (TCCRP)?

Which option accurately describes the proliferation rate and risk factors of low nuclear grade breast neoplasia?

What type of phenotype is most commonly associated with Tall Cell Carcinoma with Reversed Polarity?

Which of the following is a method for in situ hybridization used for HER2 testing?

Breast Cancer

Symptoms: Nipple discharge, lumps
Triple Assessment: Clinical features, imaging (mammography, US), pathological examination (histology, IHC)
Routine Tests: Estrogen receptor (ER), progesterone receptor (PR), HER2 (for Trastuzumab-based therapy)
- Immunohistochemistry (IHC) tests for ER, PR, HER2, Ki67, and others
- In situ hybridization (FISH, CISH, DDISH) for HER2
- Newer techniques include PCR, NGS, WGS
Ductal Carcinoma In Situ (DCIS): 20-25% of screened cases
- Stage before cancer invades
Low Nuclear Grade Breast Neoplasia: Family of precursor and invasive lesions
- Similar immunophenotype and molecular features: Loss of long arm of chromosome 16 and gain of 1q
- Similar nuclear features and low proliferation rate
- Different risk factors, better response to therapy, and a less aggressive course than high-risk lesions
Types of Low Nuclear Grade Breast Neoplasia:
- Grade 1 ductal, tubular, lobular, mucinous carcinomas (histological types)

Secretory Carcinoma

Pathognomonic Feature: ETV6-NTRK3 gene fusion
Treatment: Small molecule inhibitors (larotrectinib and entrectinib) targeting NTRK3 and other NTRK family members
Further Testing: Need for ETV6-NTRK3 tests

Tall Cell Carcinoma with Reversed Polarity (TCCRP)

Characteristic Feature: Invasive breast carcinoma with cell nests arranged in a predominantly solid, papillary pattern; reversed polarity of nuclei; and lack of myoepithelial cells around nests.
Molecular Characteristics: Expression of both low- and high-molecular-weight cytokeratins; triple-negative or weakly hormone receptor-positive phenotype
Prevalence: Seen in 84% of cases; not commonly found in other invasive breast cancers

IHC Subtypes

Luminal A: ER, PR+ HER2-, low Ki67
Luminal B: ER, PR +/- HER2+/-, higher Ki67
HER2+: ER, PR-, HER2+3 score, +2 FISH
Triple-Negative: ER, PR-, HER2-
HER2 Low: ER, PR-, HER2 +1/+2, FISH -

BCL2

Marker of good prognosis across all subtypes

Therapy

Neoadjuvant Therapy: Used in early breast cancer (BC)
Immunotherapy: Indicated for PD-L1 positive metastatic TNBC
HER2 Low: Considered negative; not suitable for anti-HER targeted therapy
Targeted Therapies: Pembrolizumab, Atezolizumab, Enhertu

This quiz covers key aspects of breast cancer including symptoms, diagnostic assessments, routine tests like hormone receptor analysis, and specific types of neoplasms such as Ductal Carcinoma In Situ (DCIS). Explore the techniques used in pathology and the significance of low nuclear grade lesions. Test your knowledge on the latest methodologies and their implications for treatment.