First, remember that progression free survival is a time to event, composite endpoint
It is typically the time until 1 of 4 things happen
Death, New lesions, Growth (without shrinkage) or Growth (from Nadir).
Watch my free lecture series to learn more:
As a result PFS is binned
It has a stair-step pattern b/c imaging is assessed not continuously, but at pre-specified time points
One can imagine that as a result: how often you assess the endpoint is important.
Very frequent assessment is rare in the messy reality of life, but might be common in trials
This can turn even trivial changes in tumor growth in stat. significant p values of <0.05!
aka $
We assessed how often PFS was checked in trials in our paper
Indeed it is checked frequently. Often less than 8 weeks is mandated for protocol specified scans.
Relentless scanning may be a tactic to find significant results for small gains
In many cases, the frequency of scanning in trials is more than guideline recommendations
Our study could not find a difference in the hazard ratio comparing different trials with different scan intervals, but this caveat is important to consider 👇👇
A future study should compare real world scan intervals to trial scan intervals. If anyone has access to data & is interested; email our lab, we would love to collaborate @vkprasadlab
There's not a single randomized controlled trial that shows people who undergo a coronary artery calcium test live longer than those who do not undergo it. Everyone will benefit from increasing exercise and eating better and the score is irrelevant
Maybe the only cancer screening test that has any utility under 35 is the pap smear. Mammography doesn't improve survival at any age, and has no data in this age group. Totally crazy recommendation
Glad that we @vkprasadlab have published over 20++ peer reviewed papers on COVID19 policy to date & many more to come
I will share them here & a free link to all of them at end
We see policy failure
#1 visitor restriction
It was sad to separate family from dying people, & had no data
Cloth masking 2 year olds was an unforced error by @cdcgov and @AmerAcadPeds, who pushed this policy with no credible data, and despite its obvious silliness
Long COVID is an evidence based disaster
There is a strong narrative that is not well supported by the evidence.
To date, besides anosmia, there is no evidence COVID has any more long symptoms than being equally ill with any other respiratory virus. period.
A new 22 page essay by Mariana Barosa, @ID_ethics and me!
"We argue that high-quality research, namely by means of well-designed randomized trials, is ethically obligatory before, during, and after implementing policies in public health emergencies"
🧵 link.springer.com/article/10.100…
Our essay reimagines the status quo. Instead of implementing and deimplementing and never knowing the answer, Public health must work to reduce uncertainty.
Shown nicely in Figure 2
We discuss many Non pharmacologic interventions tried and their limited evidence
This table represents an evidence based disaster. Nearly none of these were tested with proper trials
Forget beach closures and taking the swings out of parks
When I read an #ASH23 abstract that asks whether PFS or MRD is a surrogate endpoint in FL (L) or CLL (R), I know instantly the person on the left did it right and the person on the right messed up
Small cell lung cancer is a horrible diagnosis, and I feel sadness for anyone who has it
A double lung transplant for small cell lung cancer is complete nonsense. @VUMChealth is just making things up. This story is so sad bc doctors want to practice on the island of Dr Moreau
Just OUT! By @DavidBenjaminMD
We discuss evidence for STARTING & STOPPING cancer drugs!
What do I mean?
Currently in cancer med, we ~always start treatment at first sign of metastatic disease, and stop at progression, but....
🧵 (follow)
free link authors.elsevier.com/a/1i2MQ7tJEDS6…
... does this make sense?
The table shows trials testing early starting vs. delayed starting of systemic Rx.
For many diseases, there is no advantage to treating even widespread, asymptomatic disease
For most disease, however, there is no study at all!!
We truly don't know
But generally we assume. In many tumor types, we treat even asx or mildly symptomatic metastatic diseases (denovo or recurrent)
Now, lets consider the flip side of the coin. When should we stop treatment....