{ "@context": "https://schema.org", "@type": "Organization", "name": "Brainscape", "url": "https://www.brainscape.com/", "logo": "https://www.brainscape.com/pks/images/cms/public-views/shared/Brainscape-logo-c4e172b280b4616f7fda.svg", "sameAs": [ "https://www.facebook.com/Brainscape", "https://x.com/brainscape", "https://www.linkedin.com/company/brainscape", "https://www.instagram.com/brainscape/", "https://www.tiktok.com/@brainscapeu", "https://www.pinterest.com/brainscape/", "https://www.youtube.com/@BrainscapeNY" ], "contactPoint": { "@type": "ContactPoint", "telephone": "(929) 334-4005", "contactType": "customer service", "availableLanguage": ["English"] }, "founder": { "@type": "Person", "name": "Andrew Cohen" }, "description": "Brainscape’s spaced repetition system is proven to DOUBLE learning results! Find, make, and study flashcards online or in our mobile app. Serious learners only.", "address": { "@type": "PostalAddress", "streetAddress": "159 W 25th St, Ste 517", "addressLocality": "New York", "addressRegion": "NY", "postalCode": "10001", "addressCountry": "USA" } }

Week 6 Flashcards

(78 cards)

1
Q

Why is an understanding of cancer pathology important

A

Explains how cancers present clinically:
-rectal bleeding
-cutaneous mass
-jaundice
-haemoptysis, respiratory distress
Histopathological assessment important for:
-diagnosis: tissue confirmation required to diagnose cancer, tissue for subtyping the cancer, need to understand terms used in pathology reports
-prognosis: tumour grading and staging
-treatment: eg surgical resection, chemotherapy, radiotherapy
-additionally ancillary test eg molecular testing for prediction of chemo/immunotherapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Neoplasia

A

A neoplasm is a mass of cell that:
-have undergone an irreversible change from normality and
-proliferate in an uncoordinated manner
-are partially or completely independent of the factors which control normal cell growth
Neoplastic growth persists even if the initiating stimulus is withdrawn
Neoplasm literally means “new growth”: a commonly used synonym for neoplasm is tumour (swelling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Definition of cancer

A

A malignant neoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Classifications of neoplasms

A

Behaviour - benign or malignant
Histiogenesis- tissue of origin/differentiation
Histological- sub typing within a tissue
Functional- hormonal secretion
Behaviour and histiogenesis are two most important features used in classifying neoplasms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Benign vs malignant neoplasms

A

Malignant neoplasms have the capacity for:
-local invasion into surrounding tissue
-spread to distant sites to form secondary deposits (metastases)
—metastasis occurs via two main routes (lymphatic and haematogenous)
The term cancer is used to describe all types of malignant neoplasm
Some neoplasm behave in an “intermediate” manner
-eg basal cell carcinoma of skin - invades local tissues, but doesn’t metastasise)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Liver haemangioma, benign neoplasm- well circumscribed

A

Neoplasm of vasculature structures of liver- haemangioma
Typical appearance of benign neoplasm: well circumscribed- doesn’t invade locally

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Staging of malignant neoplasms

A

Staging= extent of spread (local or distant)
Numerous staging systems exist
-some are disease/organ specific
-a commonly used generic system is TNM
T=tumour
N=nodes
M=metastasis
Staging has important implications for prognosis and treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Neoplasia- tissue of origin

A

Epithelial
-most malignant neoplasms termed ‘carcinoma’ (eg skin, lung, GIT)
Mesenchymal tissue:
-many benign neoplasms eg soft tissue “lipoma”, muscle “leiomyoma”, blood vessels “haemangioma”
-if malignant termed “sarcoma”
-mesothelium- mesothelioma
Other:
-haemato-lymphoid neoplasms, termed “lymphoma” from lymph nodes or “leukaemia” if involving blood cells
-germ cell neoplasms- teratoma, Seminoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Differentiation

A

Differentiation is the degree to which a neoplasm histologically resembles its tissue of origin
Benign neoplasms- always well differentiated (always closely resembles tissues of origin)
Malignant neoplasms- differentiation variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Grading

A

Grading is a term used to describe the degree of differentiation
Grade 1- well differentiated
Grade 2- moderately differentiated
Grade 3- poorly differentiated
Grading has implications for prognosis and treatment
-poorly differentiated cancers behave more aggressively
-well differentiated cancers have better prognosis and certain well differentiated cancer eg prostate can be managed conservatively
Some malignant tumours are so poorly differentiated that it’s impossible to determine their histiogenesis. These neoplasms are called anaplastic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Classification of common neoplasms

A

Epithelium origin:
-squamous— squamous cell papilloma (Benign), squamous cell carcinoma (malignant)
-transitional- transitional cell papilloma (b), transitional cell carcinoma (M)
-glandular- adenoma (B), adenocarcinoma (M)
Mesenchyme:
-fat— lipoma (b), liposarcoma (M)
-fibrous tissue— fibroma (b), fibrosarcoma(m)
-smooth muscle -leiomyoma (b), leiomyosarcoma (m)
-skeletal muscle- rhabdomyoma (b), rhabdomyosarcoma (m)
-cartilage- chondroma (b), chondrosarcoma (m)
-bone- osteoma(b), osteosarcoma (m)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Thyroid carcinoma
Different behaviour according to histological subtype

A

Papillary: freq 75-85%, lymphatic spread (lymph node metastasis), very good prognosis 5 year survival>95%
Follicular: freq 10-20%, haematogenous spread (bone metastases), good prognosis 5 year survival >80%
Anaplastic: freq 5%, local invasion, poor prognosis (most dead within 1 year)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Classification of neoplasms functional

A

Classification according to substances produced
-endocrine neoplasms secreting functionally active hormones
-insulinoma= insulin producing pancreatic islet cell neoplasm
-prolactinoma= prolactin producing anterior pituitary neoplasm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Other tumours and tumour like conditions

A

Teratomas
Embryonic neoplasms
Hamartomas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Teratomas

A

Neoplasms derived from embryonic germ cells
Have the capacity to form representatives of all 3 germ cell layers (totipotential cells)
Teratomas occur in the following sites:
-ovary- usually benign
-testes- usually malignant
-midline structures (retroperitoneum, mediastinum)-behaviour variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Embryonic tumours

A

Arise from neoplastic transformation occurring in the developing organ
Derived from multi-potential embryonic “blast” cells and given the suffix- blastoma
Frequently have divergent differentiation eg epithelial and mesenchymal
Majority present at or soon after birth. Commonest type of neoplasm in childhood
Most are highly malignant (but may respond well to aggressive treatment)
Examples:
-nephroblastoma (Wilma’s tumour)
-hepatoblastoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Hamartomas

A

Not genuine neoplasms but tumour like malformations
Many present at birth and stop growing when the host stops growing
Examples: peutz Jeghers polyp, bronchial hamartoma, biliary duct hamartoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Comparison between benign and malignant neoplasms

A

Essential differences
Gross appearance
Microscopic features
Growth characteristics
Effects on host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Essential differences between benign and malignant

A

Invasion: B=no, M=yes
Metastasis: B=no, M=yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gross appearance benign vs malignant

A

Shape: b=well circumscribed, m-irregular
Size: b=generally smaller, m=generally larger
Haemorrhage: b=unusual, m=common
Ulceration: b=unusual, m=common
Necrosis: b=unusual, m=common

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Microscopic features benign vs malignant

A

Nuclear size: b=normal, m=enlarged
Nucleoli: b=small/inconspicuous, m=prominent
Pleomorphism and loss of polarity: b=absent, m=often marked
Mitoses: b=infrequent, m=frequent (may be atypical)
Differentiation: b=good, m=variable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Anaplastic carcinoma

A

Big nuclei
Prominent nuclei
Several mitoses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Growth characteristics benign vs malignant

A

Speed: b=slow, m=rapid
Spontaneous arrest: b=common, m=rare

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Comparison between benign and malignant neoplasms effects on host

A

Mechanical pressure: b=yes, m=yes
Invasion: b=no, m=yes may damage vital structures
Metastasis: b=no, m=yes common cause death
Paraneoplastic syndromes : b=no, m=yes (esp lung cancer) neurological, haematological, endocrine, immunological, other
Death: b=very uncommon, m=frequent (if untreated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Pathology as a clinical discipline
Specimens from living people Approx 70% of hospital diagnoses based on pathology “tests” -majority are simple tests (eg blood samples) -others are more complex and invasive (eg biopsies, surgical resection, specimens, molecular biology tests) Information also important for prognosis and treatment
26
Why is an understanding of tumour pathology important
Clinical presentation and natural history Terms used to classify neoplasms and their clinical relevance Treatment options
27
How are neoplasms classified
Behaviour- benign or malignant Tissue of origin/differentiation Histological subtypes Knowledge of gross features helpful in distinction between benign and malignant lumps (clinical examination, radiology) Benign= smooth, well circumscribed, mobile Malignant= irregular, poorly defined, may be fixed to adjacent tissues
28
Fibroadenoma
Commonest benign breast neoplasm Mostly occurs in young women <30 Smooth well circumscribed lumps, highly mobile on palpation (“breast mice”)
29
Breast carcinoma
Commonest malignant breast neoplasm Commonest cause of cancer death in women Mostly occur in older women (75%>50 years) Irregular, poorly circumscribed lumps, rarely mobile on palpation (due to invasion of surrounding structures)
30
In which layer of the colon do majority of neoplasms arise
Mucosa
31
Colon carcinoma- clinical presentation
Caecum/ascending colon: often polypoid, rarely cause bowel obstruction, insidious presentation- eg anaemia, weight loss Sigmoid colon: often stenosing, frequently cause bowel obstruction, typically present with alteration in bowel habit
32
Specimens obtained for pathological assessment
Biopsies: -endoscopic biopsies (upper and lower GIT, bronchus) -needle biopsies (radiologically guided) -punch biopsies (skin) Cytology specimens (cells-individuals or small groups) -smears (eg cervical) -endoscopic brushings -body fluid (eg sputum, urine, effusion fluids) -fine needle aspiration specimens Surgical resection specimens Frozen section specimens (intraoperative)
33
Biopsies and cytology specimens
Mainly taken to confirm a diagnosis of malignancy and identify histological type Information used to plan further treatment -eg surgical resection versus non surgical approaches -decisions relating to therapeutic options are frequently made in multidisciplinary team meetings
34
Limitations of biopsying tumours
Tumour heterogeneity Targeting the lesion accurately: -small lesions -inaccessible (or potentially dangerous sites) -surrounding stromal reaction (pancreatic cancer)
35
Cytology specimens
Diagnostic material obtained using less invasive methods -bladder cancer- urine cytology versus cystoscopy -fine needles used to aspirate material for cytology are much thinner than those needed to obtain biopsy material —may provide access to sites not suitable for biopsy (eg pancreas) Smaller tissue samples provided (individual cells or groups of cells rather than tissue cores) -interpretation may be more difficult than larger specimens obtained using biopsy)
36
Surgical resection specimens
Surgical resection is generally indicated to be a definitive (curative) treatment for cancer. In some cases it may be used in a palliative manner Pathological assessments are used to: -confirm the diagnosis of malignancy -determine the aggressiveness of a tumour (histological grade) -assess the extent of spread (histological stage) -examine completeness of excision This information may be used as the basis for determining further treatment (eg adjuvant chemotherapy) Other pathological assessments can sometimes be used to identify more specific therapeutic options
37
Tumour resection specimens- macroscopic assessment
Size Shape (well circumscribed or irregular) Extent of local spread Proximity to surgical resection margins Identification of lymph nodes (important for staging) Other macroscopic features where relevant (eg colour, haemorrhage, necrosis)
38
Tumour resection specimens- microscopic assessment
Confirms (or establishes) a diagnosis of cancer Other features that are assessed microscopically include the following: -histological type (glandular, squamous) -degree of differentiation (histological grade) -frequency of mitoses -local invasion —presence: is important in determining a diagnosis of malignancy (eg capsular invasion in follicular carcinoma of the thyroid gland or hepatocellular carcinoma) —extent is important in staging Vascular invasion Examination of lymph nodes (for metastases)
39
Hepatocellular carcinoma
Well differentiated tumour showing capsular and vascular invasion Presence of capsular or vascular invasion confirms diagnosis of malignancy Presence of vascular invasion up stages tumour from T1 to T2
40
The royal college of pathologists minimum datasets for reporting cancer
Describe core data that should be provided in histopathology reports Uniform approach to handling resection specimens: -prognostic information -accurate data for cancer registration -feedback on the quality of resection -selecting patients for adjuvant therapy (including clinical trials) -auditing effectiveness of pre-operative staging procedures
41
Histological grading hepatocellular carcinoma
Well differentiated: closely resembles tissue of origin, may also be classified as low grade, grade 1, more favourable outcome Undifferentiated/anaplastic: Anaplastic= no resemblance to any normal tissues in site of origin, may also be classified as high grade Grade III, poor prognosis
42
Staging of malignant neoplasms
Staging is a measure of the extent of spread of a tumour most important factor predicting prognosis in most tumours TNM. T(1-4), N(0-3), M(0-1)
43
Role of immunohistochemistry and molecular pathology
Immunohistochemistry: -a method of detecting the presence of specific proteins in cells or tissues, an antibody for each antigen Molecular pathology: gene mutation analysis; FISH; deletion of specific translocations -to support the diagnosis (specific translocations in sarcomas (myxoid liposarcomas, synovial sarcoma, Ewing’s tumour) -to predict response to targeted drugs (KIT in GIST; EGFR2 in breast adenocarcinoma; RAS in colorectal adenocarcinomas)
44
Immunohistochemistry in tumour pathology
Prognostic markers: -markers of cell turnover (eg Ki-67 labelling index) -may be used to determine tumours of low or high metastatic potential —eg pancreatic endocrine neoplasms (also applies to other endocrine neoplasms) —most cases well differentiated (low grade) by conventional histological criteria and behaviour difficult to predict -Ki 67 labelling index <2% low metastatic potential -Ki 67 labelling index >20% high metastatic potential Also used to determine prognosis (and sometimes treatment options) in tumours already known to be malignant. Often correlates with other histological features (mitotic activity, degree of differentiation)
45
Identifying therapeutic options
Expression of specific antigenic markers used to identify tumours that are likely to be amenable to specific therapies targeting the antigens expressed -breast carcinomas expressing the growth factor HER2 can be treated with herceptin -breast carcinomas expressing oestrogen receptor may be amenable to hormone therapy -metastatic colonic (and gastric) adenocarcinomas showing deficient/loss of mismatch repair proteins can be treated with immunotherapy
46
Role of molecular biology
Diagnostic: -translocations in sarcomas and lymphomas -B and T cell clonality -KIT/PDGFRA gene mutation in GIST Prognostic: -1p 19q LOH in gliomas: better prognosis -mismatch repair protein alterations in colorectal cancer: better prognosis -immunoscore: prognostic/predictive in colon cancer -oncotype, prosigna, endopredict in breast cancer Predictive
47
predictive tests in molecular biology
Targeted treatments; -HER2 amplification in breast, oesophageal/gastric and lung cancer – RAS mutation prior to anti EGFR1 antibody in metastatic colorectal ADC: negative predictive marker – EGFR1 mutation prior to anti EGFR1 small molecules in NSCLC (tissue or/and plasma) – KRAS G12C in lung cancer – KIT/PDGFRA mutation in GIST and melanoma – BRAF mutation in melanomas and lung cancer prior to targeted therapy – ALK, ROS1, RET translocation in lung cancer – MET exon 14 skipping mutation in lung cancer – NTRK translocation testing in any solid tumour – PIK3CA mutation in breast carcinoma – FGFR2 rearrangement and IDH1/2 mutations in cholangiocarcinoma – MMR testing in upper GI cancer – PD-L1 expression prior to check point inhibitor therapy: lung, head and neck, melanoma, bladder, breast, oesophageal, gastric, cervical carcinoma
48
Integrated report including pathology, gene mutations, protein expression profile, chromosomal alterations
Optimal pathology report of a cancer -histology: nature of tumour and sub typing through immune profile -immunohistochemistry single test, IVD protocols, quantification on digitalised slides -DNA analysis in FFPE and plasma single mutation, NGS -FISH partial automation of interpretation on digitalised slides
49
Multidisciplinary team meetings
Many important decisions relating to the diagnosis and treatment of malignant neoplasms now take place in the setting of MDT meetings Core members: -histopathologists -radiologists -surgeons -oncologists -other health care professionals (eg specialist nurses) The presence of recognised MDT meetings and regular attendance by core members is now a requirement in order for a hospital to be recognised as a cancer treatment centre Regularly monitored by cancer peer review teams
50
History of leukaemia
Original descriptions by Cragie, Virchow, Bennett 1840 First description of Philadelphia chromosome- 1960 Chronic myeloid leukaemia other landmark discoveries : -Janet Rowley et al: a new consistent abnormality in chronic myelogenous leukaemia identified by quinacrine fluorescence and giemsa staining Historical treatment options: -1964= hydroxyurea -combination therapy -1975=bone marrow transplantation -1983=interferon alpha -2001= imatinib
51
CML epidemiology
1-2/100000 Scotland 0.9/100000 (2008) Increases with age Virtually none below 8 years old (rare in children)
52
(Chronic) myeloproliferative diseases
Excess of myeloid cells Primary polycythaemia- too many red cells Primary thrombocythaemia- too many platelets Idiopathic myelofibrosis- too much marrow fibrosis Chronic myeloid leukaemia CML- too many neutrophils They’re all related in a way all can transform into something else
53
Chronic myeloid leukaemia
A type of myeloproliferative disease: -accumulation of myeloid progenitors -high white blood cell count -large spleen Can transform into acute leukaemia Previously treated with: -myelosuppressive therapy (hydroxycarbamide) -transplantation
54
Peripheral blood film from patient with CML
Many mature granulocytes Basophils Blast cell
55
The Philadelphia chromosome
Almost every patient with CML will have a Philadelphia chromosome 90% The Ph chromosome: t(9;22) translocation
56
CML involves 2 genes
One is BCR lies on C22 Other is ABL lies on C9 You get fusion of part of BCR gene onto next part of the ABL gene So end up with BCR-ABL fusion gene ABL is tyrosine kinase- converts ATP to ADP to phosphorylated other proteins In normal cell ABL will not always be expressed However by fusing it with BCR it becomes constructively active inside WBC
57
BCR::ABL fusion gene
Fusion creates new gene and thus new protein You can see the gene being joined together using FISH- fluorescent in situ hybridisation You can label the genes by using fluorescent probes BCR::ABL is found in normal people as well
58
The Philadelphia chromosome t(9;22) and BCR::ABL
You get various different fusions depending on where they are joined together. Therefore have various different lengths They’re also associated with slightly different kinds leukaemia P190BCR-ABL P210BCR-ABL P230BCR-ABL
59
Presentation of CML
Variable Asymptomatic Hyperviscosity- from high WBC Specific symptoms: -bleeding -anaemia, tiredness -infection (recurrent) as WBC may not function properly
60
Patient with massive splenomegaly in chronic phase chronic myeloid leukaemia
Common symptoms and signs: -fatigue -weight loss -sweating -haemorrhage- eg easy bruising, discrete ecchymoses -splenomegaly Blood values: -Hb 7.9g/dL (anaemia) -WBC 467 x10^9/L (very high) -PIts 600 x10^9/L Massive splenomegaly: can result in rare symptoms -splenic infarction -leucostasis -gout -retinal haemorrhages -priapism -fever
61
Diagnosis
Blood count and film -elevated white cell count -low platelets and haemoglobin -film Biochemistry: -abnormal liver function can occur -impaired renal function- raised urate -raised lactate dehydrogenase LDH Need to exclude other causes eg bacterial infection, other malignancies
62
Haematological investigations
Blood counts Blood film morphology Bone marrow diagnosis Cytogenetics Molecular diagnostics
63
Haematological diagnosis
Clinical Blood tests Blood film morphology Bone marrow diagnosis Cytogenetics Molecular diagnostics (new)- FISH and QPCR
64
Karyotype analysis: G banding (giemsa)
Here is the 9-22 translocation so we have the diagnosis We also confirm this via FISH
65
PCR primers on BCR and ABL read across the breakpoint
PCR is used when you have a bit of DNA that you want to find out it’s sequence eg see if there is BCR-ABL present The easiest way of doing that is by putting one primer on BCR and one on ABL where you think the break point will be Heat up DNA, anneal the primer, polymerase it, cool, join together Every time you double the product see if there’s a BCR-ABL fusion
66
Real time quantitative PCR
When we treat the patient want to know how much of the gene is around QPCR tells you how much of the gene is there Each time the gene is copied the reporter fluorophore is released giving a signal The intensity of the signal rises exponentially Compare with a known gene ABL to know how much BCR-ABL you have
67
Therapy CML
Acute treatment: -reduce WBC —hydroxycarbamide weak chemo —leukapheresis, removes WBCs. For very high WBC and life threatening complications -prevent hyperuricaemia —gout —renal failure —allopurinal to treat this —IV fluids stop renal failure -analgesia for pain relief splenomegaly Chronic treatment: -tyrosine kinase inhibitors: imatinib, dasatinib, nilotinib, bosutinib, ponatinib, asciminib -interferon: 10-20% -allogenic transplantation
68
Imatinib is a tyrosine kinase inhibitor TKI
Potent inhibition of Abl-K, c-kit and PDGF-R Salts are soluble in water Oral bio available Not mutagenic CGP57148: a phenylamino pyrimidine derivative Imatinib mesylate fits into the ATP binding pocket of BCR-ABL protein
69
Imatinib inhibits the binding of ATP to ABL tyrosine kinase
Imatinib binds to ATP binding pocket of BCR-ABL prevents phosphorylation of target molecules. So get no downstream signalling and no cell proliferation and survival Maintains BCR-ABL in inactive state BCR-ABL is a tyrosine kinase The kinase domain of abl activates a substrate protein eg PI3kinase by phosphorylation. This activated substrate initiates a signalling cascade leading to cell proliferation and survival
70
IRIS trial
Randomised controlled trial for imatinib RCT is the gold standard for testing the efficacy of new drugs in patients It typically compares the new drug against standard treatment RCT compared imatinib to IFNalpha . 553 patients in each arm, there was cross over Results: progression free survival on imatinib is better than previous therapy
71
Response milestones
Baseline- risk stratify long term score (ELTS) Haematological: normal blood counts at 1 month Molecular : BCR::ABL -<10% 3 months -<1% 6 months (complete cytogenetic response) -<0.1% 12 months (major molecular response) <0.1% any time onward
72
Minimal residual disease MRD monitoring of BCR-ABL PCR transcript levels an integral part of management of CML patients on TKI inhibitors
BCR-ABL transcript numbers expressed as log reduction in patients responding to treatment
73
You must take the drug (imatinib) >90% of the time to get an adequate response
If you have gotten down to that level your life expectancy is the same as anyone else
74
BCR/ABL mutations are the most frequently reported mechanism of resistance to imatinib
Kinase domain mutations occur in 30-50% of cases of acquired resistance. Mutations fall into 4clusters Resistance manifests itself through different mechanisms causing -changes to the stability of the BCR-ABL conformation -reduction in binding efficiency of imatinib
75
Next generation BCR-ABL inhibitors are active when the disease is resistant to imatinib
Nilotinib Dasatinib Bosutinib Ponatinib. T315I activity Asciminib. Allosteric inhibitor- not the ATP pocket Next generation nilotinib is more effective than imatinib for newly diagnosed chronic myeloid leukaemia
76
Nilotinib versus imatinib for newly diagnosed chronic myeloid leukaemia
Progression to the accelerated phase or blast crisis 14 patients: 12 patients 4.8% receiving imatinib 2 patients 0.7% receiving 300mg of nilotinib 3 patients (1.3%) receiving 400mg of nilotinib
77
Haematopoietic stem cell transplant
High dose (myeloablative) chemotherapy or chemo-radiotherapy for recipient- kills leukaemic cells and existing marrow components= conditioning Re-infusion of haematopoeitic stem cells -autologous cells (collected if marrow not involved) -allogeneic from HLA-matched donor (sibling or unrelated) Pre-engraftment and post transplant -extreme vulnerability to complications of infection, bleeding etc immunosuppressed Establishing a chimera= donor haematopoiesis/immune cells, recipient tissues, you are yourself but blood is from someone else
78
Allogeneic HSCT remains only curable option
Works well chances of survival reasonably good for young patients But only around 30% patients rate eligible for HSCT because: -age -morbidity -donor availability