Speakers from all over the world came to the University of Pennsylvania
campus to share research and ideas on how to fight back against a common enemy:
malignant mesothelioma (
MM). Topics included biology, genetics, immunology, carcinogenesis, epidemiology,
pathology, gene therapy, clinical studies and treatment options. I will
post the relevant abstracts from the three day conference below.
My main focus was on the treatment options. I came to learn. I was impressed
with the enthusiasm shown by several speakers, most notably
Dr. Harvey Pass,
Dr. Lary Robinson,
Dr. Jack Ruckdeschel,
Dr. Daniel Sterman,
Dr. Larry Kaiser,
Dr. Stan Mikulski and
Dr. Sam Hammar. I thought there was a real spirit of cooperation, despite the language
barriers, among all the doctors and researchers. I was also impressed
that our friends from Japan, France, Finland, and Italy were able to speak
English so well. Because of the large number of speakers, and the small
amount of time allotted to them, the question and comment period that
followed was often cut off, although this was usually the most interesting
segment. I enjoyed the give and take and felt privileged to witness a "
revolution in the making."
Here are my notes on the treatment options.
Dr. Larry Robinson (who has operated on two of my clients) gave an excellent
speech about his experiences at H. Lee Moffit Cancer Center in Tampa Bay
with the Extra-Pleural Pneumonectomy (EPP). He said at the outset that
there is no standard treatment or magic bullet cure for mesotheliotics,
and acknowledged the importance of a positive mind set by the patient
in overcoming the tumor. He also stressed that the best hope that a mesothelioma
patient had to prolong his life was the EPP, citing to the work of David
Sugarbaker and Valeri Rusch.
Dr. Robinson's paper focused on the downsides of administering chemotherapy
(adriamycin and cisplatin) prior to surgery. He and Dr. Jack Ruckdeschel,
his colleague at H. Lee Moffit gave chemotherapy to three patients. The
good news was that the chemotherapy cocktail reduced the size of the tumors.
The bad news was that when it came time to debulk the tumor, they found
that the chemo had obliterated the "extrapleural plane along the
endothoracic fascia," which prevented a safe EPP. Fortunately, the
three patients have shown better than expected survival with the chemotherapy
alone. Because of these findings, Dr. Robinson does not administer chemotherapy
prior to the EPP. He favors performing the surgery first and then following
up with appropriate post surgical treatments.
Dr. Ruckdeschel raised several points throughout the conference that indicated
to me that he was trying to wake people up to some common falsehoods that
are casually thrown about when talking about correlating survival with
various treatment options. If I understood him correctly, we should stop
talking about median survival and talk about one year survival as a benchmark.
The goal, he said, is to eradicate the tumor. The only plausible cure
must involve the EPP procedure. Without it, the chances for survival are
remote. Dr. Ruckdeschel asked rhetorically what's the point of advising
a patient about median survival statistics when they want a cure. They
could die on the operating table, but they could also live a long life
if all goes well.
Both Dr. Ruckdeschel and Dr. Robinson were realistic about surgery's
limitations. The best surgeon will not be able to scrape out or remove
all traces of microscopic mesothelioma tumor. But a surgeon with a trained
eye knows where to look and what to look for. Why perform a pleurectomy
only, he asked, if this will only leave resectable tumor behind in a patient
with a good performance status? The point: get as much of the tumor out
as you reasonably can (from the lung, the linings, the diaphragm and the
heart sack), and then attack with chemo and, if useful, radiation. Before
the Conference a client of mine gave a glowing report about Dr. Ruckdeschel
-- "we just love him." Now I know why. He is tough, gentle,
smart, and an advocate.
Several doctors also raised an interesting point about pre-surgery prognostic
factors. Most doctors agreed that the three keys to a successful surgery
are: (1) being able to identify the size of the tumor, which is sometimes
very difficult with a CT scan, (2) being able to determine whether there
is lymph node involvement, also difficult to measure, and (3) being able
to determine whether the tumor has penetrated the diaphragm or metastasized.
In other words, there is not yet any universally accepted way to precisely
and economically identify and measure the staging of a MM tumor. A doctor
from Finland spoke of the MRI as a much better diagnostic tool than the
CT scan (and of course the standard chest x-ray). But MRI's don't
reliably tell us whether the lymph nodes are involved. The best way to
determine lymph node involvement is through exploratory surgery.
Several doctors stated that many of the conclusions about whether a particular
treatment modality has a favorable response percentage are skewed, they
argued, because of "selection bias." That is, many patients
with advanced mesothelioma that is unresectable will not be included in
certain studies. So we may see a high survival ratio for a particular
treatment, but it can also be said that the patient may have survived
nearly the same amount of time with no treatment if nature was allowed
to run its course (because of the youth and vigor of the patient, the
small size and isolated location of the tumor, lymph node involvement,
etc). Many of these comments were made in the context of discussions about
Dr. Sugarbaker's and Dr. Rusch's published articles.
By the way, doctors from Europe universally lauded Drs. Sugarbaker and
Rusch as the pioneers in developing viable surgical treatment options.
Unfortunately, the doctors in Europe, Australia and Japan have not had
the same success with the tri-modal therapy on their patients.
All of which raises a good point that was made by Dr. Stan Mikulski, the
director of the Onconase Phase II study. Onconase has been administered
since 1992 on 63 patients through 1996 (they have added another 37 this
year alone, whose results were not included in the analysis presented).
Dr. Mikulski pointed out that his population consisted mainly of patients
who had exhausted most of their options and were found to be unresectable.
To compare apples with apples, the only way to measure the efficacy of
Onconase is to compare it to the population of mesotheliotics who were
found to be unresectable and left untreated. Dr. Valeri Rusch reported
that out of 170 or so MM patients, she did not perform the EPP on 30 because
of advanced tumor. The median survival for these unlucky patients was
5.5 to 6 months. The median survival time from date of treatment for the
63 patients included in the Onconase study was 10.1 months, which is twice
the untreated median survival ratio [24.7 months mean from date of diagnosis].
Dr. Mikulski has not yet published the results of the Onconase protocol.
His interim conclusions are summarized as follows: (1) Onconase has demonstrated
single agent activity against unresectable MM in patients who have failed
previous systemic therapies; (2) the estimated overall median survival
time observed for the 63 patients was 10.1 months from time of treatment;
(3) of the 26 patients who have been enrolled for at least one year prior
to the analysis, 42% survive today; and (4) the agent is very well tolerated
(especially as compared to standard chemo agents), with only 8% of the
subjects dropping out because of adverse reactions.
Dr. Mikulski, who is very personable and candid, advised me that he will
be talking to oncologists on the West Coast to expand the number of clinics
and hospitals that are administering Onconase. He is now spearheading
a Phase III trial that will compare Onconase vs. Doxorubicin as a single
agent approach. Enlisted in the Phase III trial are clinics in Detroit,
Chicago, Pennsylvania, New York, Austin, Texas, among others (nothing
so far on the West Coast).
Geography, in my mind, is another important prognostic factor. In general,
patients treated on the East Coast of the U.S. tend to live the longest
compared to mesotheliotics diagnosed and treated anywhere in the world.
I think a patient's survival can be linked to (1) the expertise of
their pulmonary doctor and/or oncologist, (2) where they were diagnosed
geographically, and (3) the will of the patient to educate himself and
his medical team, and pursue options, which may involve travel.
Currently, the only surgeons with experience in the EPP that I know about
are in Florida (Dr. Robinson), Detroit (Dr. Pass), New York (Dr. Valeri
Rusch), Philadelphia (Dr. Larry Kaiser), and Boston (Dr. David Sugarbaker).
As a side note, I have two clients in Los Angeles who recently advised
me that they have been referred to a Dr. Robert McKenna at Cedars Sinai
in Los Angeles, who has advised that he has performed numerous EPPs on
mesotheliotics. The point is this: in major metropolitan areas where there
is a hotbed of mesothelioma diagnoses, such as Seattle, San Diego, San
Francisco/Oakland, Seattle, Beaumont, Houston, etc, to my knowledge (please
prove me wrong!) there are no surgical oncologists who assert themselves
as experts with this tumor. In Houston, doctors at MD Anderson, a teaching
hospital with a phalanx of smart surgeons, have refused to operate on
any mesotheliotic, regardless of staging. This raises ethical issues,
in my mind.
A corollary to the prognostic factors above is whether the patient is on
the internet. Many of the doctors thanked me for referring patients to
them. Other doctors also were amazed at how quickly the word gets out
about cutting edge treatment options. The availability of patients who
eagerly want to pursue options should help the medical community organize
Doctors from France, Japan and Italy presented the results of phase II
clinical studies using combined chemotherapy agents. In France, a mix
of Cisplatin, Fluorouracil, Mitomycin and Etopside were used in four cycles
on 50 patients with unresectable MM. The response rate (meaning the rate
of patients who showed at least 50% shrinkage in the tumor) was 34% with
a mean response duration of 11.7 months. The overall median survival time
was 16 months. The French doctor indicated that he was pleased with these
figures, and said they were not too different from the median survival
times for patients with lung cancer. He said they might start using interferon
and interleukin 2 along with the standard combination. [Dr. Ruckdeschel,
who has a very quick mind and has no patience for nonsense, pointed out
that the survival rates between lung cancer and mesothelioma patients
are not as close as the French doctor suggested].
Another French Phase II study used Taxol (Paclitaxel) and Cisplatin (CDDP)
in 17 advanced unresectable pleural MM patients. They concluded that this
combination was not effective (median survival was 18 months from diagnosis).
They are now pursuing a phase II trial using chemotherapy and immunotherapy
(interferon and IL-2).
Several doctors, Dr. Harvey Pass and Dr. Ruckdeschel among them, compared
the progress in treating mesothelioma with the giant strides made in treating
Non Small Cell Cancer (NSCC). Twenty years ago the medical community pronounced
the NSCC patient dead on arrival. Now, it is one of the cancer cell types
that is the most amenable to treatment. They noted that there is a move
away from pessimism in the medical community, but we all know it is a
very slow move (see notes about MD Anderson terminating the EPP and the
lack of good surgeons on the West Coast and in the Midwest). More trials
are needed. Articles are published frequently, but the question is whether
the doctors in small rural towns or in big city hospitals are taking the
news seriously. With the onset of the internet and its gateway to timely
medical information, and the increasing incidence of mesothelioma diagnoses
in the U.S., there should be no shortage of patients to fill the protocols.
We need more and better trained doctors.
In Italy, a clinical trial using intrapleural and systemic recombinant
interleukin-2 (rIL-2) on 31 pleural MM patients showed a response rate
on the tumor mass of 22.5%. The response rate on pleural effusions was
90%. Side effects were moderate. Given the existence of side effects,
several doctors questioned whether this was worthwhile since pleural effusions
can be treated surgically fairly easily and painlessly.
Dr. Ruckdeschel also raised the point that taxotera (a chemo agent manufactured
in France) has been shown to target the pleura and is highly toxic to
malignant mesothelioma cells in vitro. Several doctors responded that
they would like to see a phase II trial using taxotera as a single agent
approach to MM. In addition to Taxotera, other chemo agents with promise
included Hyaluronanidase. According to Dr. Pass, although this agent has
not been thorougly tested in a trial, studies indicated a 50% response
rate. Dr. Pass was "intrigued" with the possibility that Hyaluronanidase
might help facilitate the invasion of the tumor by cisplatin, since mesothelioma
tumors secrete agents that stimulate the production of hyaluronan.
Photodynamic Therapy. A doctor from Amsterdam, Holland spoke about the use of Photodynamic
Therapy (PDT) during surgery on nine (9) MM patients as a promising addition
to the anti-mesothelioma arsenal. The speaker noted that Dr. Pass was
the pioneer in this approach. Dr. Pass, who is an excellent speaker with
a refreshing ability to cut through the jargon, commented that we are
climbing the learning curve with the help of new technologies, such as
upgraded diode lasers, sensitizers and light delivery systems.
By the way, Dr. Pass is a very warm human being with an endearing "bedside
manner." Among all the speakers, he seemed to know the most about
more subjects. A modern Mesothelioma Renaissance Man! In a non-threatening
manner, he made intelligent criticisms of other speakers' work and
offered helpful insights about his own experiences as a surgeon and researcher.
He seemed at home on virtually any topic ranging from immunology, genetics,
chemotherapy, clinical trials, and politics. Like Dr. Kaiser, Dr. Robinson,
Dr. Sterman, and Dr. Ruckdeschel, Dr. Pass has a genuine enthusiasm about
beating back mesothelioma.
Gene Therapy: The Best is Yet to Come. Gene Therapy aims to boost the body's immune
response to foreign invaders like mesothelioma tumor cells. [Link to the
PRIMER on the webpage] To put the state of the art for gene therapy in
historical perspective, a speaker compared where we are now to where aviation
was at Kitty Hawk when Orville and Wilbur Wright soared a few hundred
feet some two feet off the ground. Baby steps. The UPENN gene therapy
team in all was very conscientious and realistic. When patients call in,
they understand the conflict: patients want to be cured. But UPENN cannot
offer a cure at this time. First, UPENN must tackle fundamental problems,
such as figuring out how to transfer the altered gene to all of the mesothelial
cells (which can be diffusely distributed). Also, it's difficult to
engineer a cancer eating virus or antibody when we don't know at the
genetic level how mesothelial cells turn malignant.
Dr. Sterman seems to know as much as anyone in the world about the gene
therapy approach to MM. He spoke of the Phase I clinical trial, which
involved 15 patients who have been followed from November 1995 to January
1997. The study was allowed to proceed because they had obtained some
interesting responses with mice. In mice, the gene therapy actually shrunk
full blown pleural mesothelioma tumors down to a microscopic level. However,
even with the tumor regression, the mice still died. The 15 human subjects
ranged from age 37 to 74 and the mean age is 65. The most important finding
from the study from the scientific viewpoint is that they did find evidence
that the gene actually transferred to some of the mesothelioma tumor cells.
Unfortunately, the genes would not transfer beyond 3 or 4 tumor cell layers,
which is not good because mesothelioma tumor clusters can be several centimeters thick.
Of the 15 patients, 7 died after treatments. The median survival after
treatment was 23 weeks. They found no evidence of tumor regression. Toxic
side effects were minimal and one of the patients is still living 17 months
after the treatment.
Which raises the question, why would anyone want to participate in the
UPENN study? UPENN has strict criteria for eligibility: no prior chemo,
no pleurodesis, no resection, good performance status, etc. If a person
has a stage I tumor that might be resectable, why would he opt for something
experimental at best? I asked Dr. Sterman about this ethical quandary.
His answer was clear and thoughtful. He personally screens all the applicants,
and there have been hundreds. If the applicant's status indicates
that he/she may have a more reasonable hope for a longer survival using
surgery, chemo and/or radiation, Dr. Sterman will advise them to seek
help from specialists, the names of whom he will glady give the patient.
UPENN has several trials on going. It appears that the US and Australia
are the leading countries in the race to find a gene therapy treatment
for mesothelioma. Dr. Sterman hopes that they can develop a gene therapy
that can be administered during a surgical debulking operation. Also,
it is very expensive to manage, staff and equip a qualified team of gene
therapy researchers. It sounded like we were very lucky that the University
of Pennsylvania and a few other organizations were underwriting the research.
An interesting side note: an australian geneticist spoke more optimistically
about the use of gene therapy in humans. He said their goal is to help
the body do what it in extremely rare circumstances is able to do on its
own--that is, a "spontanous regression." The body can attack
and kill the invading cells in particular organs. Why can't the white
blood cells and macrophages then spontaneously attack and kill cancer
cells? A question easier asked than answered. The doctor showed us the
magical case of a woman in Austrilia with a large pleural mesothelioma
tumor. She did not have any treatment but a few months later he took a
CT scan and it was clear that the tumor had radically regressed! How?
They took a biopsy and examined the tumor tissue and found a swarm of
macrophages and lymphocytes that her body spontaneously generated to fight
off the tumor. Incredible. As usual, Nature sets the best model. [If we
could find away to clone her white blood cells!] The Australian doctor
felt strongly that the prospects were good for finding a gene therapy
partial solution to the mesothelioma problem.
But here's a question. Many of the researchers indicated that the incidence
of disease was stabilizing in their countries. Only the industrialized
countries sent representatives (nobody from Africa, Latin America or South
America attended). On a curve, it is forseeable, especially in "enlightened
societies" who have banned the commercial and industrial use of asbestos
fibers, that after a sufficient latency period you would not expect to
see any substantial number of mesothelioma cases. In the U.S. for example,
where there are very few background exposure hotspots (e.g., Libby, Montana,
Globe, Arizona, Coalinga, California), if you assume that all friable
asbestos has been abated and no more fresh asbestos products are being
used, it would seem logical that one day we will be seeing markedly fewer
cases. The question is: by the time we find a "cure", what will
be the size of the MM population? In the U.S., the number of new cases
will be peaking in 2010 or so. I wonder sometimes whether our government
takes the nihilistic view that the costs of trying to find a cure for
mesothelioma are outweighed by the benefits because eventually we will
be seeing fewer cases and the epidemic will fade away quietly.
Which brings up the AIDS model. The US Government has financed basic and
clinical research on finding a cure for AIDS. Why? I think it has to do
with the political savvy of the AIDS patients and their advocates. They
have been very strident about getting their message out and demanding
government subsidies and assistance. Asbestos victims have a few advocacy
groups, and this is not meant to rebuke the work that they have done,
but certainly our "crusade" has not had the same political impact.
One of the doctors at the conference privately suggested to me that we
form a foundation to help fund basic research by independent thinking
medical and scientific experts who will pursue the lure of a cure with
the same zeal that swept Watson and Crick to discover the DNA double helix.
This is a good idea.
It is difficult to distill three days and over 50 speeches into a catchy
theme. But the take home message seemed to be: we have come far, but we
have a long way to go. They seemed to appreciate that their task was not
academic. They realized that the stakes are high, that thousands of people
worldwide are afflicted with this terrible disease. I detected an esprit
de corps among these medical pioneers, a passion, if you will, to search
out and destroy malignant mesothelioma and prevent it from ever rearing
its ugly head again. Unfortunately, there was very little mention of issues
like prevention, responsibility, and quality of life.
Also in the audience were several friends of asbestos. I noted a representative
from the National Insulation Manufacturers Association and several doctors
who have happily testified for the asbestos comapnies: Dr. Bernard Gee
(a likeable English fellow), Dr. E.A. Gaensler, and Edward Ilgern, an
industrial hygienist who consults for the W.R. Grace Co. It's sad
that instead of devoting their talents and intelligence to finding a cure
or helping to reduce the risks still faced by millions, these medical
mercenaries have joined up with the dark side to help the asbestos industry
cover up or sugarcoat their nasty record of death and disease.
Which raises two problems I had with the conference: one, the totally unproven
and unsupportable suggestion that mesothelioma may be caused by a contaminated
poliovaccine (SV40), and, two, a haphazard and ill-placed speech by Edward
Ilgern, a consultant to the W.R. Grace Company, who rushed through a speech
that, in my mind, sought to downplay the existence of tremolite related
death and disease in Libby, Montana. He also tried to argue the tired
argument that chrysotile does not result in serious death because we have
not seen a rash of mesotheliomas around Coalinga, California. I looked
it up on the map and it appears to be a tiny little town in central California
about 7 miles West of Interstate 5 and about 40 miles SW of Fresno as
the crow flies. I wonder how many people have lived there for more than
20-25 years who might have been exposed to what I'm told is a chrysotile mountain.
First, the poliovaccine whitewash. From 1953 to 1963, the poliovaccine
used in the U.S. was (I'm told) contaminated with SV40, a virus. Researchers
in Italy (also funded at the University of Chicago) suggested that the
SV40 was capable of infecting the mesothelial cells. The researchers suggested
that the SV40 may act in combination with asbestos fibers in inducing
cancer. However, there is no research that studies the incidence of mesothelioma
among non- asbestos exposed persons who received the SV40 poliovaccine
compared to asbestos exposed persons who did not receive the vaccine.
The "hypothesis" was hotly debated. In the crowd were several
long time friends of the asbestos industry who no doubt were already contriving
ways to incorporate this flimsy argument into their next court room testimonial
in an effort to muddy the waters for the jury.
It would not surprise me if the Asbestos Industry Trade Associations has
begun to recruit researchers who will give credence to the poliovaccine
virus causes mesothelioma argument. If the SV40 virus truly were a mesothelioma
co-factor, in view of the fact that millions of Americans were vaccinated
against polio from 1953 to 1963, it would seem logical that we would be
seeing a substantially higher number of mesothelotics without any exposure
The Libby whitewash. Ed Ilgren, a W.R. Grace consultant, spoke about the
incidence of disease in Libby, Montana, home of the W.R. Grace/Zonolite
Co. Vermiculite processing mine and mills. He suggested that 50% of the
reported mesotheliomas in 1982 among Libbyites could not be linked to
asbestos exposure. He said that the diagnoses lacked confidence because
an autopsy was not performed. He also said one could not safely point
to tremolite asbestos as a co-factor because there were other sources
of asbestos exposure in and around Libby. He noted that the town's
drinking water was contaminated with creosote, implying that other carcinogens
were responsible for the high incidence of cancer in Libby. He did not
mention the fact that for years W.R Grace dumped hundreds of tons of tremolite
contaminated mill tailings into the river upstream from the town's
water supply intake pipes. Nor did he talk about the incidence of asbestos
related diseases among actual employees with more than ten years of exposure
or their relatives. Nor did he even attempt to make the issue relevant
by bringing up-to-date the number of reported mesothelioma, lung cancer
and asbestosis cases that have been diagnosed since 1982 ( a very large
number). It left me puzzled and dissatisfied.
I could tell that he had a bias so I approached him after his presentation.
I asked him about the data he relied on and where he got it (he thanked
several corporations before his speech for their assistance, including
Grace, Manville, Union Carbide and others). He asked who I was. I told
him I was a lawyer. He asked if I represented plaintiffs. I said yes.
He then said that he would not speak to me, that it would be "a conflict
of interest." I reminded him that I was simply asking him what data
he was relying on and, moreover, the facts I was relying on where verified
under oath from Grace employees (like Earl Lovick). Imagine it. He can
get up before a hall filled with scientists, doctors, researchers, industry
apologists and government officials and downplay the carcinogenesis of
tremolite and chrysotile asbestos, but he won't talk to a lawyer who
was asking simple questions about what data he was relying on to reach
his sweeping conclusions.
He later admitted that the Grace mining and milling plants were "shitholes".
He also kept wanting to draw a distinction between the nasty plant conditions
before Grace purchased the plant and the scrubbed version after Grace
bought it. He kept repeating the year 1976. I reminded him that W.R. Grace
bought out the Zonolite Company in 1963. The "shithole" to which
he was referring was in fact owned and operated by the same company who
pays him to testify that tremolite is benign and that the plant was clean
-- W.R. Grace.
A few more parting shots: three days of speeches from the world's best
and brightest did not yield any discussion on possible treatments for
peritoneal mesothelioma. They seem to be forgotten.
Also, it's cliche, but it bears repeating: an ounce of prevention is
worth a pound of cure. There was no mention that Mesothelioma is preventable
if we eliminate asbestos exposures. There was a speaker from Russia who
spoke about the carcinogenesis of asbestos in rats -- hardly a fresh topic!
Meanwhile, in Abest, Russia, they continue to mine and manufacture millions
of tons of raw asbestos. There were speakers from Canada, which continues
to be the world's leading exporter of chrysotile asbestos. I understand
many asbestos products are still being used in France, and I'm sure
this is the case in most of Asia and Japan, as well as South Africa.
Finally, a bit of history.
An epidemiologist from Canada spoke about the high levels of asbestos in
the air in the towns of Asbestos, Thetford Mines andBlack Lake, all located
in Quebec. These open pit asbestos mines were open for business in 1880.
He wanted to assess the risk faced by women in these mining towns for
getting mesothelioma. Tremolite asbestos was a significant source of the
airborne fiber. Dr. Camus talked about his research methods to determine
what the levels of exposure were for housewives in these towns back in
the 1930s, 1940's, 1950's and so on. One source was the women
themselves. He asked them about the levels of dust in the town. They reminesced
about how on windy days the entire town was covered in a fog. They spoke
of a fine film of asbestos dust on the city sidewalks each morning. They
joked that on Sunday Morning the town busybodies could tell who was going
to Church and who wasn't by the size of the footprints on the sidewalk!
He showed us pictures from the 1950s showing that the mill tailings piles
were taller than the top of the church steeple in the town. We also saw
photographs of the asbestos contaminated piles that backed up against
the homes and yards of the townspeople.
The epidemiologist talked about the mesothelioma risks that bystanders
(women who did not work in the mines or mills) in Asbestos and Thetford
Mines faced relative to the general population elsewhere. He said that
a threshold level above which a person will likely contract asbestosis
is "25 Fiber Years." To put that number in context, he estimated
that the inhabitants of Thetford Mines had cumulative exposures of 122
Fiber Years! Dwellers of Quebec had the equivalent of 74 Fiber Years.
He noted that there were a higher incidence of mesothelioma cases in Thetford
Mines, which was a richer source of tremolite than the town of Asbestos.