Another Perspective on Treatment Decisions
As parents of children with neuroblastoma,
we often make treatment decisions based primarily to two factors. The
first is based on response. What treatment has the highest response
rate? What treatment is going to create the biggest change? The second
thing we consider is toxicity. What side effects come with this
treatment? What is the impact on quality of life? Will something bad
happen? We then take these two factors, mush them up in our brains, and
spit out the answer for what treatment plan we follow.
Done. Easy answer.
Hold
on. Unfortunately, this formula misses some very important
considerations and often can lead you astray. The fact is that we don't
live in a world which only has two factors - response and toxicity.
Every decision we make has implications which will impact future
decisions. In this way each decision also caries a significant risk
factor. There is risk that a particular choice will make you ineligible
for something later on down the road. There is risk that your child may
not respond or the risk that something will happen that will preclude
you from getting treatment. As I will try to demonstrate today, these
are all extremely important factors that should weigh heavily on any
decision. In today's high risk neuroblastoma treatment reality these may even be the most important factors to consider.
This is where my difference of opinion lies.
One
of the appealing aspects of treatment at Sloan Kettering is the promise
of no transplant. According to them, in their experience, they do not
believe a transplant is necessary when antibodies (3F8) are used for
consolidation of minimal residual disease. I should point out that this
is in direct contradiction to three large randomized phase 3 trials
which showed that transplant increased event free survival by 11% or
more (these trials did not include the use of antibody, however.)
Regardless, when analyzing the toxicities of transplant it is easy to
be swayed by the allure of not having to have a transplant and the hope
of achieving the same desired result. It is very appealing. People
evaluate the response - children appear to achieve remission in similar
numbers - and then they evaluate the toxicity - it isn't a transplant.
The problem with this type of thinking is that it misses some extremely
important factors. First and foremost, it misses the point that you are
giving up on the proven standard. This is not additive treatment, this
is "instead of" treatment. By not transplanting, you are risking the
loss of an increase in survival of over 10%. It may very well turn out
that the doctors at Sloan may be right. Someday, it may be proven that
a transplant is not necessary given the medical technology at that
time. But, in the meantime, you are very definitely adding more risk to
your child's chance of success by not transplanting. You are gambling a
10 to 15 percent increase in survival in the hope that this other
treatment (antibodies) will do the same job - a job that they are yet
to be proven to accomplish. I think every one would agree that, in this
case, if you looked at it from the perspective of this type of risk
(the risk of decreasing survival), the best option would be to do both.
Another
risk that many people do not think to consider is the risk of not being
able to receive the treatment. This is one of the saddest realities of
all. What if you decided to go to Sloan Kettering? What if you decide
to reduce your risk of toxicity from transplant and forgo it? What if you decide to use 3F8 for consolidation instead?
What if you HAMA'd in the first or second round precluding further treatment?
This
risk is significant. It happens. There are kids sitting in this
scenario at this very moment - kids that could have been transplanted
and received antibody. But, the question remains. You gave up
transplant in the hopes of reducing toxicity in favor of a relatively
unproven treatment (for this purpose) and now, because of a fluke,
because of an immune reaction, you are no longer eligible to receive
that treatment either. Or, you are no longer able to receive that
treatment again with out some significantly high doses of chemotherapy
- high doses of chemotherapy which offer significant toxicity but still
do not provide you the benefit of a transplant or any guarantee that
you will be able to get enough antibody to get the job done. In this
scenario, the nightmare, you have actually increased your risk on at
least two fronts. Your decision cost you the benefit of a transplant
(11%+) and the benefit of antibody (20%). By choosing this route you
have effectively reduced your chances of survival by over 30%. Could
you go back and do a transplant? Probably. But, would you become
eligible for the ch14.18 antibody? Not today.
That is a big gamble - an especially big gamble for something that is yet to be proven.
The
third risk is the risk of treatment failure. I know this is something
that no one wants to consider but, it too does happen. In fact, I have
seen some articles quote numbers as high as 20% (or higher) of patients
fall into this category. In this scenario, the standard therapy has
failed in induction. You have done your due diligence yet, even given
the best medical knowledge we have, your child has failed induction.
What are the risks here? What impact did your decision of which path to
take have in this scenario? I think the risk here is in eligibility.
You see, if you fall into this category of patients the most important
thing you can have is options. By participating in a standard induction
you are naturally eligible for several options that you might not be
otherwise. An example of this would be an MIBG/transplant
regimen. This type of transplant has been extremely effective for a
subset of these individuals. In fact, for some, this was the ticket
that got them back onto the road to survival. I am not advertising this
trial but simply pointing out that this is a treatment that is
available and effective for a certain subset of the non responding
population that may not be available to them if you decided on a
different path from the beginning. It is just one example of risk in
this group of patients.
Finally, before I run out of internet,
I would be remiss if I did not address the most obvious but less
publicized risk. By choosing not to participate in a COG trial, at this
point in time, you run the risk of not being able to receive the
ch14.18 antibody. This is the one antibody that has been proven in a
randomized phase 3 trial to increase survival by an additional 20%. One
could easily argue that choosing not to utilize ch14.18 carries
inherent risk.
Now, please, don't send me email telling me that
3F8 can do everything that ch14.18 can do. Trust me, I know what it can
do. The point is that by choosing 3F8 over ch14.18 you are taking on
more risk. At this point in time ch14.18 is a proven commodity. We
don't know whether 3F8 works better, the same, or worse. Furthermore,
with 3F8, we also have the additive risk of an early HAMA - a risk that is greatly minimized by the ch14.18 antibody.
You
see, today is not about response or toxicity. My arguments have
absolutely nothing to do with which treatment is better. That is
another discussion entirely. This entry is about reducing risk and
increasing options.
Risk is the third ingredient of the
treatment decision that we often forget to consider fully. This is
unfortunate when, as I have demonstrated today, it just might be the
most important component.