breast cancer

Question 1

diagnosing breast cancer

Answer 1

Self-examination, mammograms, further imaging (X-ray, ultrasound), and biopsy for histopathology.

Question 2

how can liquid biopsies be useful in diagnosing breast cancer?

Answer 2

detect biomarkers found in body fluids, such as blood, urine, or saliva.
Circulating Tumor Cells (CTCs)
Circulating Tumor DNA (ctDNA)
Tracking Metastasis

Question 3

What are the two main cell types from which breast cancer can arise?

Answer 3

Answer: Carcinomas, derived from epithelial cells (99%), and sarcomas, derived from mesenchymal connective tissue cells (1%).

Question 4

What is the role of molecular subtypes in breast cancer treatment?

Answer 4

Answer: Molecular subtypes help guide treatment by identifying specific drug targets and tailoring therapies to individual patients.

Question 5

How is breast cancer staging classified?

Answer 5

Answer: Using the TNM staging system, where T represents the tumor size, N refers to lymph node involvement, and M indicates metastasis.

Question 6

5 stages of sub-typing

Answer 6

carcinoma/sarcoma
invasive/in situ
histological
TME
biomarkers - HER2 / ER(or ERB2) / PR

Question 7

What is the role of fibroblasts in breast cancer?

Answer 7

Answer: Fibroblasts can protect cancer cells from chemotherapy and may influence the tumor’s response to treatment.

Question 8

How does the presence of BCRP protein relate to chemotherapy response in breast cancer?

Why?

Answer 8

Answer: High BCRP levels after chemotherapy are associated with a poorer response to treatment and higher recurrence rates, while low BCRP levels after treatment indicate better prognosis.

Question 9

What is the main function of the protein “Breast Cancer Resistance Protein” (BCRP) in relation to chemotherapy?

Answer 9

Answer: BCRP is a drug pump that can reduce the effectiveness of chemotherapy by pumping out the chemotherapy drugs from cancer cells, leading to cancer cell survival.

Question 10

What are the implications of tumor classification in determining breast cancer treatment?

Answer 10

Answer: Tumor classification, including histopathological type, stage, and molecular profile, helps define the appropriate treatment options and predict treatment response.

Question 11

What is the primary treatment strategy for early-stage breast cancer?

Answer 11

Surgery
followed by drugs and/or radiotherapy to kill remaining cancer cells.

Question 12

What are the main challenges in current breast cancer classification?

Answer 12

Answer: The range of treatment responses within each subtype, and the difficulty in predicting specific responses to treatment, highlighting the need for more accurate classification.

Question 13

What is the significance of “neoadjuvant therapy” in breast cancer treatment?

Answer 13

Answer: Neoadjuvant therapy involves administering chemotherapy before surgery to shrink the tumor, making surgery less invasive and allowing for better monitoring of treatment response.

Question 14

what signalling pathways are common in her2-positive bc?

Answer 14

PI3K/AKT/mTOR Pathway = resistance to apoptosis

MAPK - RAS/RAF/MEK/ERK Pathway = cell cycle progression

Question 15

Treating Breast Cancer

Answer 15

Treatment: HER2-targeted therapies
trastuzumab,
pertuzumab
lapatinib
HER2 drives uncontrolled proliferation. These therapies block HER2 signaling, inhibiting growth in HER2-positive breast cancers.

Treatment: CDK4/6 inhibitors
ribociclib,
palbociclib
- cell cycle arrest by inhibiting G1-S phase transition.

Treatment: PI3K/AKT/mTOR inhibitors
alpelisib
everolimus
- bypass tumor suppressors like PTEN. Inhibiting this pathway reduces cell survival and proliferation.

Question 16

list the RTKs and nuclear hormone receptors found in breast cancer
(5 listed)

Answer 16

HER2 - RTK
Estrogen Receptor (ER) NHR
Progesterone Receptor (PR) NHR
BRCA1 and BRCA2 Tumour suppressor genes
p53 mutations

Question 17

HER2

Question 18

Estrogen Receptor (ER)

Answer 18

Definition:
If a breast cancer is ER-positive, it means that the cancer cells have receptors for estrogen, a hormone that can stimulate their growth.

Significance:
ER-positive cancers grow more slowly and are
more likely to respond to hormone therapy,
such as tamoxifen or aromatase inhibitors,
which block estrogen or reduce its production.

Question 19

Progesterone Receptor (PR)

Answer 19

Definition: A protein similar to ER, found on some breast cancer cells. If a cancer is PR-positive, it indicates that the cancer cells respond to the hormone progesterone.

Significance: Like ER-positive cancers, PR-positive cancers are typically less aggressive and are more likely to respond to hormone therapy

Question 20

BRCA1 and BRCA2

Answer 20

Definition: Tumor suppressor genes that help repair damaged DNA. Mutations in BRCA1 or BRCA2 significantly increase the risk of breast and ovarian cancers.

Significance: Tumors with BRCA1 or BRCA2 mutations tend to be more aggressive and may respond well to targeted treatments like PARP inhibitors (e.g., olaparib).

Question 21

list all the subtypes based on receptors

Answer 21

luminal A - ER and PR
luminal B - HER2 and ER and maybe PR
her2 +
tripple neg