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Lung Cancer
Kenneth Albert, MD
Lung cancer is not the most common cancer in either men or women. Prostate
cancer is certainly number one in men and breast cancer is number one in women.
It cuts lung cancer at approximately half; so you can see breast cancer
is much more common than lung cancer. However, if you look at the deaths from
cancer, lung cancer, it is by far the biggest killer in both men and women.
If you look at the changing incidence of lung cancer in men, the United
Kingdom is actually decreasing quite substantially from the earlier 1960s and
'70s. In the United States, it actually leveled off in the 1980s, and it has
started to decline in the last couple of years, and in France it is still
rising. So it really just depends on where you are and on your habits. In women,
the United States is still going up. It hasn't showed any sign of leveling off.
The United Kingdom has already leveled off and started to decline a little bit.
In France, it is has always been low.
Types of lung cancer. There are two major types: non-small cell and small
cell. Approximately 75-80% of the tumors that we see are non-small cell, while
only 20-25% are small cell itself. If we look at the small cell subtypes,
previously the vast majority of those particularly with the disease found in
males was squamous cell cancer, but more recently the majority of them are
adenocarcinomas, and 40% of all lung cancers are adenocarcinomas. So this has
really shot up and changed the nature of the disease as well. Squamous cell is
only 17% of all lung cancers.
In smokers, particularly males, squamous cell is a fairly predominant tumor
type. But if we look at nonsmokers, Aden carcinoma is by far the most common
subtype. The same is true of females, even to a greater extent. In smokers,
adenocarcinoma is more common in females.
Staging. The T-stage is based on the size, the location, the amount of
atelectasis and a few other things. The N-stage is fairly simple. N1 is
intrapulmonary lymph nodes, N2 is outside and N3 is outside the chest and M1 is
self-explanatory.
Stage 1 and 2 are localized to the lung itself. Stage 3A is more advanced
with metastases in general or chest wall invasion and 3B is your unresectable
tumors. T3N0 is tumors that involve the parietal pleura either on the chest
wall, the diaphragm or the mediastinum, now it is considered to be stage 2 as
well since the survival is actually better. In these two groups up here, TI and
T2, each one has been divided into A and B. Now, there is 1A, 1B, 2A, 2B and
then T3 can be observed in 2B as well.
Stage1 tumors have to be less than 3 cm and it can't involve a major lobar
bronchus and create lobar atelectasis or consolidation, and it can't have any
lymph node involvement either in the lung or outside. T2, they are just bigger
lesions. Either greater
than 3 cm or those that involve the visceral pleura and that cause lobar
atelectasis. Segmental atelectasis is the T1 finding. Stage 2 is the same two
groups except for there is intrapulmonary lymph node involvement so that the
criteria are the same. This is 2A, this is 2B but there is intrapulmonary lymph
nodes either along the segmental bronchi or either the lobar bronchi that are
involved. Also, again, 2B consists of T3, which is tumors that are involved in
the parietal pleura or 2 cm with carina.
3A is locally advanced. T3N0 again goes to the 2B now but T3N1 and 2, T3
involves basically anything that has parietal pleura. if you see something with
complete collapse of the lung, by definition they have to have a T3 disease.
The other component of a 3A is N2 disease and that means now lymph nodes up
in this area that are involved. So you can kind of get a feeling from the number
of different subgroups in this phase that there are a lot of different patient
populations in here. N2 disease is a lot different from T3 disease so
implications in terms of survival and treatment are also different.
3B again is something that is unresectable in general which includes N3
disease which is either contralateral, if you have a tumor over here,
contralateral lymph node involvement on the opposite side or a scalene lymph
nodes in this particular area or you have a T4 lesion which is either a tumor
growing into a major structure like an aorta, esophagus, left atrium or some
major unresectable organ or a malignant pleural effusion.
One of the things surgeons keep in mind is the spread of tumors along lymph
node chains. If you have an upper lobe lesione and up along the peritracheal
nodes here so
the subparietal nodes are oftentimes spared or the left side is spared. If
you have a middle lobe or lower lobe lesion, it tends to drain not down here
actually but to the subparietal lymph nodes and then up along the right side. On
the left side actually, the lower lobe tends to drain to the subparietal nodes
and then switches over to the righ side as well so you get more contralateral
involvement of the left lower lobe. The left upper lobe tends to drain along
this direction. Just like the right upper lobe it also goes to the AP window
which is on the left side.
So when you see a report where someone on mediastinoscopy biospies a
mediastinal lymph node, it is not accurate enough. It doesn't tell you enough
information to really be able to treat the patient as well as they can be
treated. Stage 1, clinically the survival is the best - 50-55%. Stage 2 drops
down to 30% or less. Stage 3A is 15 or less and Stage 3B and 4 are dismal. So if
you have an accurately staged 1 patient, either T1 or T2, survival is 60-75% or
even 80% for small lesion so that is fairly reasonable.
But you the T1N0s are 75-80%. That is a pretty reasonable survival but that
means even when we start getting T2, no lymph node involvement, this is a larger
tumor or visceral pleural involvement it drops down in the 50s so you are really
just flipping a coin to see whether patients survive and then when you drop down
to stage 2, it goes down below the 30s. Generally 52 is kind of high, but it is
30-40% in most stage 2 tumors. The 3A it drops from the 30s down to as low as
15% depending upon which 3A we are talking about. Then 3B and 4 are dismal -
less than 10%. Patients unfortunately present mostly with advanced 3B or 4
disease half the time and then half the remaining patients would be the early
resectable disease, stage 1 or 2 or locally advanced, which is potentially
resectable, but may not be good to resect necessarily.
Distance spread for lung cancer as everybody knows is brain, bone, liver
adrenals, lymph nodes as well as the lungs. Those are the most common sites. But
the problem from the surgical standpoint is that no matter what you do from a
surgical standpoint, two-thirds or more of the patients fail distantly. So no
matter what you do, except for the small subgroup of patients with very small
primary lesions that we find early incidentally, the vast majority of the
patients are bound to recur. Adjuvant therapy was instituted because of the high
risk of recurrence.
The Lung Cancer Study Group as well as the Veterans' Group and other groups
studied postoperative chemotherapy, postoperative radiation, postoperative
chemotherapy and radiation and then more recently looking at preoperative
therapy, either chemotherapy or chemo radiotherapy.
Postoperative adjuvant radiation therapy and has a benefit for stages 2 to 3A
from postoperative treatment which increased local control from around 80-85% up
to 97% or better. But the problem is it doesn't translate into increased
survival because of the fact that it is not a local problem that kills the
patient. It is the systemic metastases.
Postoperative chemotherapy was looked at extensively and people always bring
up the point that this is CAP chemotherapy and most of the postoperative trials
were done with chemotherapies that are not used any longer because they are
inferior and so nobody really knows now whether postoperative chemotherapy would
work or not. There are some people that are starting to look at that again. But
this is one study, again by the Lung Cancer Study Group looking at Phase 2 and 3
patients, the immunotherapy control arm which is basically no therapy and did
not see significant overall survival advantage although the disease-free
survival was slightly prolonged.
The dismal result of all of these trials led people to try and think of new
ways to give therapy and one of the newer ways was neoadjuvant therapy, also
called preoperative therapy induction therapy. That is giving some kind of
therapy prior to definitive local control measures. Local control measures can
either be radiation or surgery but some of the therapy given before that. So in
terms of surgery, neoadjuvant therapy that has been looked at includes both
chemotherapy, chemoradiotherapy and radiation therapy alone.
There have been a number of preoperative radiation trials looking at
preoperative radiation by itself prior to surgical resection and those haven't
shown any benefit. In fact, even in Pancoast's tumors, the classic treatment
that was developed back in the '50s and '60s was to treat these patients with
preoperative radiation therapy then resection. That is still done in most places
now. But the more that we view their data in terms of the radiation therapy and
in looking at intraoperative administration, preoperative or postoperative,
patients did the same no matter what they did so that the combination of
chemotherapy and radiation is important but the order is not necessarily
important. So there are some areas like in St. Louis where they don't get
preoperative therapy, just resect the tumor and give them postoperative therapy
and it seems to work out the same. So preoperative radiation has never really
been shown to be definitively better than the surgery alone with postoperative
adjuvant if needed. So what I want to do is look at some of the data from stage
3A disease and what I mean by 3A, there are a lot of different types of 3As.
They used to be T3N0 which is now 2B but I am going to talk about them anyway
because all of the trials have included those patients. You can see survival for
those patients with T3N0 is 40-50%. Usually closer to 50% so that is why they
have been changed recently to 2B because their survival really doesn't fit into
3A. Then N2 disease is not even a single disease. An N2 can be a micrometastatic
deposit in one lymph node or it can be bulky disease in multiple station lymph
nodes and their survival is dramatically different as well.
N2 positive patients. If you look at just a single station, that is one lymph
node area on that map that has been involved with tumor and the rest of them
were all biopsied and negative, which gives you about a 35% survival with
surgery alone. If you look at a single station lymph node excluding the
subcarinal area which tends to be a somewhat bilateral station and more
difficult and poor prognostically input implications is actually a better
survival if you can eliminate those patients and look at a single station that
is not subcarinal. Up to 45%. Then if you look at patients with more than one
area involved, they go down to 9%. If you again exclude the subcarinal area, it
goes up to 22% so you can see that depending on which group you look at you can
have anywhere from less than 10% survival up to 45% survival.
In terms of preoperative or induction therapy, there are a number of
advantages that have been proposed. One of them is that you treat the patient
then when primary tumor size is as small as it can be, malignant metastases are
also presumably small and they would be several months later. You potentially
might decrease surgical seating which may or may not happen. The disadvantages
that have been worried about have been the increased morbidity and mortality
from the surgical procedure, which actually has not turned out to be the case,
and delayed primary tumor control. That, as you can see from the other data, is
not the biggest worry. The metastatic disease is what kills the patient so that
has turned out not to be the case.
There are other factors in all of this. When the Lung Cancer Study Group
evaluated their adjuvant trials, one of the primary things and possible reasons
for failure was that the patients didn't tolerate the therapy very well. After
undergoing a major operation and trying to recover from that and then getting
chemotherapy. Also patients psychologically weren't ready to take more
chemotherapy because their tumor was already out and they would give up easily
and say, "I don't want anymore chemotherapy because my tumor is gone. It may not
be there anymore and I don't want anymore." So, preoperative therapies tend to
get a higher dose intensity of chemotherapy than postoperative treatment so that
may be one of the key reasons why the preoperative seemed to be work better.
The two randomized trials looking at preoperative induction chemotherapy
prior to surgical resection in 3A patients. A trial from Barcelona that was
published in the New England Journal a few years ago but these were both small
trials. They were both designed to have 120 patients in them. They were both
stopped after 60 patients by independent review boards that thought that the
results were so compelling that it was not ethical to continue the trials so
that each had only 60 patients, here 30 on each arm, this is 32 and 28. This arm
is surgery alone and in Barcelona everybody got radiation so it's surgery plus
radiation versus chemotherapy plus surgery plus radiation.
At the M.D. Anderson they got surgery and chemotherapy prior to surgery. Some
of these patients also got radiation if they had close margins or residual
disease in their lymph nodes. The chemotherapy was used, and actually again the
greatest chemotherapy, in Barcelona they used cyclophosphamide and cisplatin and
in M.D. Anderson they used cyclophosphamide which was pretty worthless,
cyclophosphamide and cisplatin.
So these aren't the kinds of modern regimens that everybody used but still
the results are kind of interesting. The third trial at NIH that never really
reached the pinnacle of significance because it only had about 27 patients in
it. It showed the same trend as these two studies. The multiple number of phase
2 trials that were done also showed the same kind of results in a nonrandomized
fashion.
But if you look at the results here in surgery alone, 85% of resectable in
Barcelona, the median survival time is only 8 months and 10 months in M.D.
Anderson. These were criticized a little bit saying, "Well this is not what we
would expect because surgical time is usually longer than that". But this data
has been looked at in terms of the Lung Cancer Study Group, they included
thousands of patients and it is actually consistent with those controls for this
stage of disease. If you look at chemotherapy prior to therapy, the median
survival time is at 26 months for Barcelona and actually it is up to
approximately 60 months or 5 years in M.D. Anderson. So that is pretty
compelling and you would think that this would be a reasonable thing to do
although people now have discounted a lot of this because some of the data that
was collected regarding K-RAS expression in these patients and both of these
groups went back and looked at the K-RAS expression and it was not balanced
between the two groups. So now people just throw out all of the results because
of that which I think is a little bit unfair because that was one of the goals
of the trial was to better the K-RAS. This is just to show you so you can see
it. This survival curve is from the M.D. Anderson trial and you can see this is
surgery alone and you do get a few survivors. It levels off and this is with
chemotherapy prior to surgery. Again, it is leveling out and there is definitely
a big difference between the two curves. It is not one of those curves where
they come down and then they eventually meet down here with the same survival.
It levels off and is definitely different. Then you look at the Barcelona and it
is hard to see but it is the same thing basically. Surgery alone comes down here
and then surgery plus chemotherapy levels off here with a definite distinct
difference in survival.
So it looks like it works. The issue of primary control is one that we
brought up. Whether surgery is necessary in a lot of these patients because they
have high dose radiation therapy along with therapy producing, at least in some
patients or advanced patients, similar results. So the question still is open
whether surgery is needed or whether you can do the same thing with
radiotherapy. The only data that we know of at least in earlier stage disease
was small lesions. We know that surgery is far superior to the radiation therapy
but in more advanced lesions like the 3A and 3B, radiotherapy has been fairly
equivalent to surgery but that is because the systemic disease is not
controlled. So if you start to control system disease, then it may end up
eventually being proven that surgery has always been a better local control
modality than radiotherapy.
This is a trial that is ongoing but it is looking at the question whether
chemoradiotherapy is better than chemotherapy alone in a preoperative setting.
So they are randomizing patients to receive again unusual chemotherapy,
mitomycin, vizicin and cisplatin and actually get a different chemotherapy
cisplatin to this group and they get radiation therapy to this group as well and
do surgery and then follow it up with either radiation or chemotherapy. So it is
kind of an unusual trial but some of the data in terms of the resectable and the
disease free survival so far has been different in favor of the radiotherapy
arm. But this is very early on and the endpoints they looked at are really
endpoints of local control and not necessarily systemic control. So
resectability response ranks a little bit higher with that we would expect with
radiotherapy so there is really no definitive evidence right now that
radiotherapy in a preoperative setting adds anything to chemotherapy. I think it
detracts from the induction therapy because what you really want to know is how
well the systemic disease is going to respond to the chemotherapy and not
whether a local tumor can respond to radiotherapy because that is what really
determines survival. So patients who respond dramatically to chemotherapy are
the ones that we can be more aggressive on in terms of resecting patients and
the radiotherapy kind of confounds that by covering up possible therapy
failures.
What I had mentioned before is there are some special considerations about
bronchial obstruction. The fact that if you have an obstructed bronchus and
potential infection beyond that, if you treat patients like that preoperatively,
there were a number of deaths when that first started being done in Toronto. It
was responsible for the major part of the mortality of this kind of approach
until it was realized they shouldn't do that. So if you do have a bronchial
obstruction, it is best to either relieve it either with surgery or radiation or
something prior to giving chemotherapy or at least know what the problem is and
cover it with antibiotic.
The major thing is to avoid a lot of hydration in patients perioperatively
because the chemotherapy patients for some reason are more susceptible to having
postoperative noncardiogenic pulmonary edema which is catastrophic in patients
who are undergoing pneumonectomies or big resections. Having had chemotherapy
makes them more susceptible to that so we need to be aware of that and keep
their fluids down, quite dry.
Now, just some data regarding 3B which is classically considered unresectable.
These there is a trial Suave 8805 which looked at actually 3A and 3B disease and
treated it with chemotherapy, radiotherapy and there is an induction protocol.
The reason this is important is because this is what is being used now in trials
with 3A disease - a similar regimen. Then they were reevaluated and patients
that seemed to have a good response and were in good shape underwent surgical
resection and this was the results from that trial. The interesting and
surprising thing about this trial was that patients with 3B disease in green had
similar survivals as those with 3A with this induction and treatment. All of
these patients underwent more aggressive surgery where they had to do bilateral
lymph node resections and that kind of thing but it kind of gives you an idea
that if you can give a good and early induction chemotherapy regimen and control
systemic metastases and potentially some of the disease that was thought to be
unresectable previously may actually be resectable.
You can't apply this widely. You have to select the patients very carefully
and also stage them very accurately and staging always, at least for most of
these trials, includes mediastinoscopy and PET scans are now being used more
widely to try and also stage patients. But we have also found that a lot of
false negatives and false positives PET scans so that still hasn't been proven.
So I think mediastinoscopy is still required in all of these patients to really
know what the risk of recurrence is and how it should be treated. M1 disease.
Patients with M1 disease occasionally are surgical candidates.
It is not very common but patients particularly with solitary brain
metastases and solitary adrenal metastases have been shown to have a more
favorable prognosis at least in terms of resection candidates than in other
patients with more widely metastatic disease.
These are theories looking at solitary brain mets and survival after surgical
resection of the brain met and the primary lung cancer. You can see the five
year survival varied anywhere from 9% to 34%. So, depending on again the
prognosis and the type of disease that is a reasonable survival. It is more like
3A survival - patients with 3A disease. So people have used this to go ahead and
do primary resections in the presence of solitary resectable brain metastasis.
Again, what we are doing now is to
apply the same approach to 3A disease to this category as well and that is
these patients have about the same survival as the patients with 3A disease,
again because of systemic recurrence. Two-thirds or more of these patients are
going to have a systemic recurrence versus any problem in primary brain site or
primary lung site.
So we are now actually taking patients with solitary brain mets, resecting
the brain metastasis, giving them chemotherapy again in an induction setting and
then going back and resecting the primary lung lesion. Again in the same way of
trying to improve survival.
The Memorial data with multiple metastases. They had 231 patients with
different numbers of resections including up to three or four resections of
solitary brain metastases over time. They found that the poor prognostic factors
were multiple metastases, incomplete resection, male gender, infratentorial
location was an important one and the presence of other systemic metastases
obviously as well as advanced age.
This looks at some of the breakdown of the 182 patients with a single
resection and their disease free survival was only five months and their median
survival was 14.6 months which is a little bit better than we would expect
otherwise. I will show you in a minute some radiation controlled studies.
Actually, patients had two and three resections and their survival was as long
as 42 months so it shows that some patients who do have limited numbers of
metastases can be controlled with surgery alone.
Again, this is not patients who received chemotherapy, so that, potentially,
these patients could have a higher survival if they had chemotherapy as well.
The five year survival is 12.5% which is a little bit less than a lot of the
other series but it shows that it is better than the general systemic
metastasis. Two-thirds died again with systemic disease which again includes
chemotherapy.
The RCOG study, 8528 looked at just brain irradiation along with the lung
primary without surgery. You can see that their survival at one year was only 20
to 33%. The early stage lung cancer. This is kind of group where people have
been treated for years with surgery alone, whether it is stage 1 or stage 2.
Anything with disease in the lung has been treated surgically. As you remember
from the survival curve that I showed earlier, the disease survival can be as
low as 30-40% in the stage 2 subgroup so this is not a really outstanding
survival with surgery alone. Again, the standard approach has been surgery,
definitive therapy, radiation therapy if patients refused surgery or seemed
inoperable. The Lung Cancer Study Group has shown with a randomized trial that
the standard surgery should be a lobectomy or pneumonectomy, which is far better
than limited resection including segmentectomies or wedge incisions. The local
recurrence rate goes from about 6% with a lobectomy to as high as 38% with a
wedge resection. The survival is inferior with those lesser resections so most
surgeons now feel lobectomy is the least you should be doing. Memorial's data
from stage 2 disease and shows over 39% five year survival so this group does
not have great survival. We have started thinking that we shouldn't accept
this as acceptable to surgery alone and apply other therapies. What we looked
at more recently is new adjuvant therapies in high risk early stage lung cancer
which includes all of these early lung cancer stages except T1N0. So, if there
is a small peripheral primary that is easily resectable, we still do that. But
anything more than that, we actually now are giving chemotherapy prior to
surgical resection. These are the number of centers that are all participating.
This is a multicenter study that we are doing now in the phase 2 setting. Giving
carboplatin and Taxol prior to resection is what all these places that are
participating are giving.
The schema of the trial is to give them two cycles of carboplatin and Taxol
and then, if they have progression of the disease when they go off treatment, if
they respond or it is a stable disease, which everybody has, they go on to
surgical resection and then three postoperative cycles of chemotherapy.
So in the future, we are looking at this poor prognostic early stage disease
looking at getting chemotherapy to T2 and N1 patients as well as T3 disease with
complete chest wall involvement. We limit it to solitary brain or adrenal
metastases but Memorial is actually giving chemotherapy in a preoperative
setting to patients who have a solitary metastases anywhere that is resectable.
Then there is 3B and M1 disease that don't really have protocols but they
eventually show some improvement. A special type of laser bronchoscope can
isolate early lesions and we are looking into screening for lung cancer patients
who are at high risk because of a previous lung cancer or are high risk for
other reasons. One of the arms of the screening is doing monoclonal antibody
screening of sputa looks very promising to identify patients with early changes
in the mucosa prior to any overt cancer. Then another one is looking at this
light bronchoscopy which is a type of blue light laser which will make
neoplastic changes or pre-malignant lesions become autofluorescent. This you can
see is the white light bronchoscopy for these areas. You can't really see much
abnormal in these areas but here you can see an extensive brown area and over
here there is more of a brown area here which are potential lesions that might
develop into tumors. So these can be hopefully related early and avoid big
resections. The other part of this treatment would be to use photodynamic
therapy to ablate these mucosal changes before they become a tumor, but it is
still experimental. You may have heard the Japanese reports of using
photodynamic therapy for early lung cancer and these are the kinds of
patients that they were attempting to use it in. Problems occur with patients
with solid masses in their lung and other things, people that are pulmonary
cripples who can't have surgery and they want to know about photodynamic
therapy. It is really not something that has been able to treat solid lesions.
The best thing to do is to find any lesion, which in the United States
are rare to find this early lesion and treat it with photodynamic therapy. But
it is something that might in the future, photodynamic therapy is very limited
and used rarely to treat patients who have had high dose radiation and have
recurrence in their airway and have a tumor growing in their airway that is not
treatable by any other means, which is rare. This is Natan trial which is
ongoing now which is looking at N2 disease which is again, there are several
questions regarding how best to treat patients with metastases but they take
what you might consider inoperable N2 disease with bulky nodes and definite N2
involvement to be treated with radiotherapy which used to be the primary
treatment modality. Well, now it is chemoradiotherapy and that is one reason why
the trial is failing recently knowing how randomized it is.
The other group is chemotherapy followed by surgery followed by chemotherapy.
So this was to look at this new way of induction chemotherapy versus the old
standard. This started a number of years ago but may actually be changed to a
different trial because they can't really finish it. The Interview trial from
NCI which is now looking at the question of surgery, as a modality. This
randomizes the chemoradiotherapy or local modality therapy in the definitive
option and then the other arm is chemoradiotherapy prior to surgery. This is
slowly accumulating patients.
The problem is that people don't like the idea of randomizing surgery or no
surgery so it has gotten a number of patients accrued but it is not accruing
very quickly. In conclusion, lung cancer basically is systemic disease and it
wouldn't surprise me at all if in three to five years we are treating everybody
with chemotherapy up front and then resecting patients who have residual disease
or radiation, depending on what turns out in those trials. Surgery is the most
effective form of local control. I would guess that I would want chemotherapy up
front followed by the most effective local control which is surgery, if
possible. Surgery is often contraindicated in higher stage disease and selected
patients we know have an increased survival. Again, surgery is something that is
to be applied very selectively and only in those patients that are looked at
very carefully and thoroughly prior to undergoing more advanced resections.
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