Role of Pathology in Cancer Diagnosis Flashcards
(27 cards)
What is pathology?
The study of cause and effects of disease and injury
What is molecular pathology?
Studying the molecules in organs, tissues or fluids to understand the cause and effects of disease
What percentage of NHS diagnoses depend on pathology?
70%
What fields/services count as pathology?
Biochem, haem, microbiology, virology, histopathology, cytopathology
What are some pathology techniques
pathomorphology, PCR, FISH, cytogenetic arrays, flow cytometry
Pathology is most important for what aspects of the patient pathway?
Diagnosis and classification and stratification
Histology was one of the first mechanisms for cancer diagnosis and prognosis. What did they tend to look for down the microscope?
Nuclear atypia, mitotic activity, cellular density, tissue architecture
What are the 5 histological cancer types? And what cell type do they come from?
C
S
M
L
L
Carcinomas (epithelial)
Sarcoma (mesenchymal, connective tissue)
Myeloma (plasma cells)
Leukaemia (begin in bone marrow)
Lymphomas (lymphocytes)
What do you need to do and know and ask to working in histology?
Know organ anatomy and cellular anatomy.
Receive a fresh specimen.
Find out as much case info as you can, including what the surgeon has done and what the clinician needs to know.
What steps are required for a good surgical resection for diagnosis?
Resect close to the margins. Determine all the cancer cells to know if it’s spread outside the margins.
Remove as many lymph nodes as possible to know the level of spread then teh grade can be correctly diagnosed.
What are prognostic factors in histology?
The margins, stage, grade, vascular invasion, lymphatics, cancer datasets, molecular markers, and evidence based practice…
How do you go from cancer to results in histology?
Remove a sample, place it on a slide, it will adhere. Fix, dehydrate, clean, embed, cut, stain. Then cell morphology stain AND/OR do a specific protein stain.
Immunohistochemistry is….
Binding antibodies to specific proteins in tissues to stain and see protein expression
Why might you want to stain for C-kit using IHC?
Imatinib can block the receptor activity of C-Kit
Name the cancer that each of these proteins are stained for in IHC.
ALK
PTEN
NCAM1
EGFR
ALK - Lung
PTEN - Brain
NCAM1 - CRC
EGFR - Stomach
Multiple markers may have to be used in IHC. Especially for what type of cancers?
Haematological
Molecular pathology looks at which molecules?
DNA, RNA, and proteins.
What techniques does molecular pathology use?
Karyotyping, FISH, PCR, RT-PCR, Microarray, protein array, Serum biomarker analysis (ELISA)
Karyotyping can tell you what?
The disease itself or the stage of the disease
What is the general karyotypic progression of CRC?
Hyperproliferation
Early adenoma
Late adenoma
Full carcinoma
Metastasis
Start with loss of 5q / FAP leading to hyperproliferation.
Then DNA hypomethylation in early adenoma.
12p KRAS mutation leads to intermediate adenoma.
18q loss/DCC mutation leads to late adenoma
17p p52 loss leads to full carcinoma
Then other alterations leading to metastasis.
What will FISH detect in CML?
BCR-ABL fusions between chr9 adn chr22
What are the 3 types of PCR? (for the purpose of this question anyway)
Single-plex
Multiplex
RT-PCR
Explain the use of each type of PCR:
Single-plex
Multiplex
RT-PCR
Single-plex - EGFR mutations in NSCLC
Multiplex - Panels like EGFR, ALK, ROS1, BRAF and KRAS in NSCLC
RT-PCR - Accurate quantification. Amplification of HER2 in 20% of breast cancers. Which can be concomitant with amp/del of topo II which may determine a response to chemotherapy
Array technologies screen many targets to build a disease-specific profile of diagnosis, prognosis, progression, and helps with therapy too. There are many platforms for it. What platform is used in CLL patients and for what purpose?
ZAP-70 is used in leukaemic cells of CLL patients to identify the correct IgVH mutational subtype
