Monitoring Disease Flashcards
What is the name of the criteria created for monitoring disease to know in a standardised way how to monitor someone and when to offer certain drugs, first done in 2000, then redone in 2009?
RECIST Criteria
For patient eligibility for the RECIST criteria, what needs to have been done?
Have at least one lesion accurately assessed by CT or MRI scan at the baseline, and then follow up visits too
What areas of the anatomy require coverage when monitoring?
All known areas with a predilection for metastasis. Normally chest, pelvis, abdomen. Plus any additional areas of concern
What are the 3 types of lesion to be monitored?
The target lesions. Non-target lesions, and any new lesions.
Target lesions and Non-target lesions should ideally be measured by CT. If not, what other methods?
MRI, X-ray, clinical examination
What additional techniques can be used to monitor new lesions?
Ultrasound, bone scan, PET scan.
You MUST use what modality for follow up?
The same as you used for baseline, even the same scanner preferable
What is the basic RECIST paradigm or method?
Do a baseline assessment. Select and measure target and non-target lesions. Start treatment. Then do follow up assessments maybe every 3 months. You then measure all the same lesions, as well as recording any new lesions
How do you choose target lesions?
They need to be clear cancer lesions, measurable accurately in at least one dimension. Good shape, lymph node can be nice and circular.
How many target lesions do you choose, and max of how many per organ?
5, max of 2 in one organ
How big must each tumour lesion be to measure using method?
CT
Xray
Clinical evaluation (with calipers)
CT for lymph nodes (must be short axis)
CT >10mm
Xray 20mm
Calipers 10mm
Lymph node short axis 15mm
How do you create the SLD, the Sum of the Longest Diameters?
You add up the longest diameters of non-nodal lesions, and the shortest diameters of the nodal lesions
How do you select non-target lesions?
Any other tumour lesion <10mm or lymph nodes 10-14mm. Could be sorts of thickening, things hard to measure on a scan. Never include if there’s a suspicion its not cancerous
What are some examples of non-target lesions?
Peritoneal plaques, ascites, pleural effusions
Bone lesions are not target lesions because the way they look may change, not good for measurements. But what can be used to confirm their presence or disappearance?
PET scans or Plain films
Bone lesions may have what that can be measured by CT or MRI?
Soft tissue components
Cystic lesions are not included as lesions usually but what may be?
Cystic metastases
What do we do concerning areas of previous radiation?
Previously irradiated areas should not be selected as target lesions unless there’s been a demonstrable progression in that lesion
What is classed as a complete response?
Disappearance of all target and non-target lesions and no new lesions.
In a complete response what happens to lymph nodes?
They won’t disappear all together, but they will be <10mm.
In a partial response what is the target percentage decrease for the SLD of target lesions?
> 30% decrease
In a partial response what happens to non-target lesions?
No progression
In Stable disease response what happens?
Neither sufficient shrinkage of growth of any target or non-target lesions. and no new lesions.
In a progressive disease response, what increase of SLD counts?
> 20% SLD increase. OR an absolutely increase of 5mm
What other reasons can be classed as a progressive disease response?
Progression of non-target lesions, or new lesions that have to be unequivocally new cancer lesions (don’t have to be measurable).
What’s a negative about identifying new lesions whilst monitoring (I mean other than it could be a worsening of the cancer)
They could be found in anatomical regions no looked at during the baseline.
Ultrasound scan new lesions should be confirmed with what?
CT or MRI
How do cells metastasise?
They perform angiogenesis, then EMT to go in the blood stream, they move around and then do an MET when they have the right environment.
CELLSEARCH is the gold standard for capturing circulating tumour cells. What method does it use briefly?
Immunomagnetic capture. Magnetic beads soaked in epithelial antibody. Blood is passed through beads, so will select for epithelial cells, which should not be present in the blood so are likely metastatic tumour cells. Then stain with other antibodies and visualise and identify.
NSCLC advanced patients with more ctCells have what survival?
Worse survival
The value of ctCells in NSCLC is not great, why?
So few of these cells, might find 0-10.
But what’s good about ctCells for long term monitoring?
Easy to take blood samples. AND when we do capture those cells, they do track with prognosis and provide utility.
CELLSEARCH isn’t good at picking up which cells?
Those that are a bit more mesenchymal than epithelial
Describe a technique that can pick up ctCells that are a bit more mesenchymal than epithelial
Using small pores that you let blood cells pass through but big ctCells get stuck in, can then stain them.
CELLSEARCH is standardised and scalable which not all technologies are. The other technologies are quite labour intensive and expensive. Name some of the others
Isoflux, parsotix, clearbridge, Gilupi, Magsweeper.
CtCells Advantages:
Invaluable to learn about metastasis. Can characterise cells for biomarkers. Potential to generate mouse models from ctCells.
CtCells Disadvantages
Expensive. Low number of ctCells. Many technologies. Unlikely to be routine for clinical decision making
CtCells have been over taken by what?
ctDNA
Why do ctDNA VAFs have to be interpreted carefully?
There may be subclones in the tumour. A change you find may not be the driver.
ctDNA assays have what sensitivity and specificity.
High specificity, but low sensitivity.
ctDNA samples are really important to what type of patients?
Very unwell and frail patients.
ctDNA technology is not quite there yet for which applications?
Early diagnosis or residual disease detection
A quick ctDNA result can prevent what?
A patient going on the default of chemo which may be harmful for their mutations.
ctDNA has been used to measure LC pateints for EGFR for several weeks, why?
Look at exon 19 and check to monitoring if there emergence of any resistance mutations like T790M.
ctDNA can detect what type of genetic changes?
substitutions, indels, CNAs, Gene rearrangements, TMB and MSI
Why are serum tumour markers now cheap as chips?
We’ve been capturing these proteins in blood tests for so long now routinely
We would love 100% sensitivity and specificity of biomarkers and what other properties?
Short half life, easily measurable and reproducible, proportionate to the size of the tumour, cost effective.
Name two very common serum marker tests?
Prostate Specific Antigen (PSA), and CA125 in ovarian cancer
Why is one measurement of serum markers not good enough?
An isolated value is no good as it needs to be compared and monitored over time. it’s not informative enough to be diagnostic.
What’s better than one marker?
A panel
