Running head: CANNABINOIDS EFFECT ON CANCER
Cannabinoids Therapeutic Use for Cancer Patients’ Quality of Life and Tumor Growth
Angelyse Kenngott
Stony Brook University
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Abstract
The current study strives to replicate and extend previous findings regarding cannabis use to
improve quality of life and decrease tumor growth for cancer patients. A group of 100 cancer
patients who are either experienced cannabis users or non-experienced cannabis users will be
compared on their quality of life questionnaire scores and tumor growths over one year. Using ttest results are expected to indicate that, experienced cannabis users will score lower on the
quality of life questionnaire compared to non-experienced cannabis users, and all participants
will have slowed tumor growth. Implications for research and applied work in the area show
cannabis is a positive treatment for cancer patients.
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Cannabinoids Therapeutic Use for Cancer Patients’ Quality of Life and Tumor Growth
Cannabis grows naturally in the plant Cannabis sativa (Walsh, Nelson & Mahmoud,
2003). Cannabis sativa creates 60 different compounds known as cannabinoids; an active
compound removed from cannabis. The most useful cannabinoid is delta-9tetrahydrocannabinol (THC) due to it high potency and abundance found in the plant (Guzmán,
2003). In the 19th century cannabis was one of the leading three medicines to be prescribed in the
United States (Huskey, 2006). In 1986 THC was approved by the FDA and is available today in
an artificial form known as Dronabinol (Walsh et al., 2003). Cannabis has been used for
medicinal purposes for thousands of years and has shown a wide array of effects on cancer
patient’s quality of life (Huskey, 2006). Quality of life for a cancer patients changes while going
through different treatments and affects their physical appearance, appetite, pain and over all
level of exhaustion. Two out of three cancer patients have reported having significant pain
during some point of their treatment, which is one of the most feared aspects of being diagnosed
with cancer, with 50% of patients not getting adequate analgesia (Huskey, 2006). Recently with
18 states making cannabis legal for medicinal use many studies have taken place to see the
effects it has on cancer patients as an alternative to many other treatments and medications used
that have negative side effects (Huskey, 2006). Although much research still needs to be done to
weigh the positives and negatives THC has on its users.
There are both positive and negative side effects that are associated with cannabis use.
Studies have shown that cannabinoids exert both positive and negative effects on the immune,
reproductive, digestive, cardiovascular, ocular and central nervous system (Kogan, 2005).
Cannabis is shown to be beneficial for cancer patients in many different aspect of their life such
as: analgesia, antitumor effect, muscle relaxation, mood elevation, and relief of insomnia, as well
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as being well tolerated by most patients (Walsh et al., 2003). Many studies have concluded that
THC has similar potency as codeine for relieving pain and could also lead to positive
psychological effects like reducing depression and anxiety (Guzmán, 2003). It has been shown
that long-term cannabis users have no changes in psychological, neurological and blood tests
(Guzmán, 2003). Some negative side effects have been found and are more common in elderly
cannabis users (Voth & Schwartz, 1997). Voth and Schwartz have found that the negative effects
of THC depend largely on the way it is delivered into the users body, the duration of use and
immunologic state of the user and can sometimes be linked to distortion of reality, dysphoria,
changes in concentration and euphoria (1997). Cannabis also has shown to have some of the
same harmful chemicals as tobacco making it harmful for long-term use (Walsh et al., 2003).
Cannabinoids have also been linked to slowing down or stopping cancer tumors from
growing or spreading. The treatment to stop tumor growth is blocking the angiogenic process;
this is the most promising antitumor approach now available for cancer patients (Guzmán, 2003).
Cannabinoids could be delivered by several different pathways and have shown to help patients
with leukemia, glioma, breast, prostate, colon, and thyroid cancer (Hermanson & Marnett,
2011). Cannabinoids kills most of the tumors cell by blocking the cell cycle and then down
regulating the growth factor the cell needs to proliferate, this also show a decrease in new blood
vessels from spreading into the cancer, in studies mice have shown to live longer lives and have
decrease tumor size (Kogan, 2005). This is an effective way to treat tumor cells because not
only does it kill the cells but it does not affect there non-cancer counterparts and it may also
protect the cells from cell death (Guzmán, 2003). Although there is a lack of preclinical data
using cannabinoids to targets the endocannabinoid system, it has been shown to be one of the
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most promising and cutting edge ways to reduce the progression of cancer in patients
(Hermanson & Marnett, 2011).
Cannabinoids in the treatment of cancer has shown many positive outcomes on patient’s
quality of life. Most patients who have been tested for using natural and synthetic cannabinoids
prefer this option to other antiemetic, and it has shown to have a less toxic effect than other
forms of chemotherapy (Guzmán, 2003). Cannabinoids are mostly used as appetite stimulates
for patients because two thirds of cancer patients have been diagnosed with anorexia which leads
to a high level of morbidity, it has been documented that anorexia, nausea and vomiting have
been the most inhibited factors of quality of life for patients (Kogan, 2005). Cannabinoids are
known to stop nausea and increase appetite. Other uses that are beneficial to cancer patients that
cannabinoids are used for include muscle relaxation, analgesia, improved sleep, decreased
anxiety, and mood elevation (Walsh et al., 2003). Most studies that have been to date have
involved the oral use of THC (Dronabinol) (Voth & Schwartz, 1997). A majority of these studies
do not take into account that the THC plasma level after use depends on many factors including:
method of use, time lapse since use, individual preference, and experience of the user (Walsh et
al., 2003). These factors will be addressed in the current study because these factors can have an
effect on results such as decreasing the validity if the experimenter does not take these into
account. There is currently a lack of research to show the effects of THC on cancer patients who
are experienced cannabis users versus the effects of THC on non- experienced cannabis users.
There is also a lot to be learned about using a vaporizer to inhale the THC because not many
studies have used this method of inhalation. Also there is lack of studies done using cannabis to
reduce tumor growth in humans.
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The purpose of the current study is to examine whether cancer patients who are
experienced cannabis users will score considerably lower on a test measuring quality of life than
cancer patients who are non-experienced cannabis users, and to see if tumor growth will decrease
for all participants. To this purpose, an experimental study will take place. The independent
variable will be the cancer patient: experienced cannabis users, and non-experienced cannabis
users. The dependent variable is the level of quality of life that will be scored using a Quality of
Life questionnaire, filled out by the participants after he/she has vaporized cannabis for a
targeted reason: pain, appetite loss and/or exhaustion, and tumor growth. Participants will use a
vaporizer to inhale the cannabis rather than burning the cannabis because it is a safer process
eliminating many toxic compounds found in cannabis smoke, and the long-term health risks of
using this method is significantly less (Walsh et al., 2003). It is hypothesized that cancer
patients with experienced cannabis use will have lower side effects which will cause them to
score lower on the Quality of Life questionnaire. In contrast it is predicted that cancer patients
who are non-experienced cannabis users will have more side effects causing them to score higher
on the Quality of Life questionnaire, and all participants’ will have decreased tumor growth. This
study could help to make cannabis a more acceptable method for increasing the quality of life in
many cancer patients; it would also help to develop a way to decrease the negative side effects of
cannabis and to reduce the growth in tumors.
Methods
Participants
Participants will be 100 cancer patients who are currently patients at Memorial Sloan
Kettering Cancer Center. All participants must have a cancerous tumor we can keep track of
growth through out the study. Fifty of the participants will be experienced cannabis users and
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fifty participants will be inexperienced cannabis users. The age range of the participants will be
21-50 with the mean age of 27.5. Fifty participants will be male and fifty participants will be
female. There will be twenty-five experienced cannabis male participants and twenty-five
experienced cannabis female participant. Also there will be twenty-five non-experienced
cannabis male participants and twenty-five non-experienced cannabis female participants. When
giving a prescreening questionnaire to all participants, XX% of participants will identify as
White, XX% as African American, XX% as Latino or Hispanic, XX% as Asian, and XX% as
other. Participants will be predominately white. Participants will come from households who
report the median income as $65,000, with a range from $30,000 to $150,000. All participants
will have a high school diploma. Participants will be recruited with fliers their doctors hand out
with information about a new study that will be conducted to increase cancer patient’s quality of
life, and reduce or stop tumor growth. There will be an expected rate of participation of seventy
five percent. Each participant will be required to sign a consent form that informs them of
procedures, what their commitments will be, and their ability to withdraw from the study at any
time, the risks, benefits, and compensation. An initial screening process will take place, which
will include a questionnaire about their side effect to treatments, quality of life, and past cannabis
use. They will also have to have a full body computed tomography scan (CAT Scan) to show the
experimenter where their tumors are located, and its current size. Only cancer patients with
cancerous tumors and a high quality of life score that shows significant pain, appetite loss and/or
exhaustion will be able to participate in this study. Participants will be compensated with free
cannabis and a cannabis vaporizer to improve quality of life, and also all doctors’ visits
throughout the study will be free of charge.
Measures
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The independent variables are the cancer patients, experienced cannabis users and nonexperienced cannabis users. Experienced cannabis users means the participants has actively used
cannabis within six months; non-experienced cannabis users are participants who have not used
cannabis in over five years, if ever. Each participant will be giving instructions on how to use
the cannabis at home and will then have to fill out the quality of life questionnaire after every
use, the participants’ can use the cannabis three times a day for one year. The main material used
in this study is not only the cannabis but also the vaporizer. The reason the participants will use a
vaporizer which is an alternative to smoking cannabis is because the vaporizer does not allow
many of the harmful toxins found in cannabis to be inhaled leading to less negative side effects,
vaporizers also allows minimal smoke to be inhaled or released so there are less harmful side
effects for the participants’ family because there is no second hand smoke (Gieringer, St. Laurent
& Goodrich, 2004). The vaporizer provided to each participant would be a hand held
rechargeable one. It will be made by the company Vapir with the model number of NO2, and
will be made of black plastic and small enough to fit inside an every day bag. It has a little small
clear plastic piece the participant would connect to the hole the vapor comes out of and they will
use that to put their mouth on and inhale. They will have to hand the questionnaires into a doctor
bi-weekly. There will only be one doctor who meets with the participants bi-weekly, this doctor
will get paid for his time. The dependent variable is the scores the participants receive on the
quality of life questionnaire, and tumor growth. The quality of life questionnaire (Kenngott,
2013) is one that the experimenter has designed on their own because he was unable to find a
previous questionnaire that had the correct type of questions to measure the effect cannabis is
having on the quality of life of cancer patients. There will also be monthly CAT scan required by
all participants so the doctor and experimenter can keep track of any changes to the tumors they
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have throughout the study. In a smaller pilot test the experimenter ran, he calculates the alpha
reliability coefficient to be 0.88 and Pearson’s coefficient to be 0.65 for retest reliability
(Kenngott, 2013). There are 50 questions on each of the quality of life questionnaire. The
questions will be rated on a 10-point scale rated by the way the participants was feeling before
using cannabis and then after using cannabis and to report any side effects they are having,
where 0= none and 10= severe. The quality of life questionnaire is a self-report questionnaire.
An example of a question is “after using cannabis the pain I am experiencing is”. The range for
this questionnaire is 500 with 0 being the minimum and 500 the maximum.
Procedures
The present study is experimental and longitudinal. The independent variable is the
cancer patients with two levels of experienced cannabis users and inexperienced cannabis users.
The dependent variable is the scores on the quality of life questionnaire, and tumor growth. The
dependent variable will be measured after every time the participants uses the cannabis by
having the participant fill out an at home questionnaire and then they will hand the
questionnaires to the doctor at the bi-weekly visits, and tumor growth will be measured monthly
at the participants CAT scans. Experimenter effects will be controlled by having the same doctor
meet with the participant’s bi-weekly, and meeting with the experimenter first to find a
structured and standard way to hold every appointment. Before the first meeting participants will
fill out a consent form with the doctor and experimenter where the cannabis, cannabis vaporizer,
instructions for use and questionnaires will be giving out. The participants are then told they can
use cannabis up to three times a day as needed when they feel pain, appetite loss and/or
exhaustion. The participants have to vaporize the cannabis when they use it and will have to use
the already distributed amount each time, they will have to pull on the vaporizer for 15 seconds
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and hold the vapor in for 15 seconds before releasing for air. The participants will also be
instructed to wait twenty minutes before filling out the at home questionnaire to give time for the
cannabis to start it effects. The cannabis will be handed out to the participants in already
weighed and grinned third of a gram amounts. To standardize the amount each participant is
using there will be enough for three uses a day for the next two weeks and the participants will
get the next two weeks amount at their next doctors appointment. The doctor and experimenter
will always dress professionally with the doctor having a lab coat on whenever coming in contact
with participants. The participants will be classified into two groups depending on past cannabis
use, making two equal groups of 50 participants, with both having twenty-five male and twentyfive female in each group. Then the groups will fill out questionnaires about past treatments,
quality of life, cannabis use, and concerns they have about being diagnosed with cancer.
Participants will then be instructed again about the cannabis use at home and how to fill out the
quality of life questionnaires at home, making sure there is a clear understanding of how to do
everything correctly. The study will run for one year with bi-weekly doctor visits that will take
place in a standard doctors office at Memorial Sloan Kettering Cancer Center. The study will
begin on February 1st and end February 1st of the following year. The participants will also have
to have a CAT scan on the first of the month every month to keep track of the tumors to see if the
cannabis has had any effect. The doctor will make sure that the rooms lighting temperature and
noise level are constant at every meeting and will also go over how the patients is using the
cannabis at home and discuss the questionnaires with the participants that they have handed in.
After these meetings the experimenter and doctor will go over the at home questionnaires the
patients filled out after using cannabis for a giving reason, this will help the doctor and
experimenter to keep an up to date understanding of how the patient is feeling, how the cannabis
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is working, and what to discuss with the participant at their next appointments. At the end of the
year the participants will take an additional quality of life questionnaire to see how they felt
about cannabis use, side effects, and if they felt they would like to continue using cannabis to
improve their quality of life, the participants will also have their last CAT scan to see if any
change has happened to their tumors over the one year. The questions used in the initial quality
of life questionnaire, the on going quality of life questionnaire and the final quality of life
questionnaire will be counterbalanced and have different wording for each questions and they
will be in a different order for each participant to prevent the confounding variable of carryover
effect.
Results
The main effect of this current study is the difference in levels of cancer patients’ quality
of life for experienced cannabis users and non-experienced cannabis users, and to keep track of
participants’ tumor growth. The hypothesis of this current study is experienced cannabis users
will score lower on the quality life questionnaire as opposed to non-experienced cannabis users
who will score higher on the quality of life questionnaire, and both groups will experience
decreased tumor growth. The independent variable is the cancer patients, and the dependent
variables are quality of life questionnaire scores, and tumor growth. The quality of life
questionnaire will determine the amount of pain, appetite loss and/or exhaustion the participant
feels before and after using cannabis. Experienced cannabis users are participants who have used
cannabis within six months, and non-experienced cannabis users are participants who have not
used cannabis in over five years. The participant must fill out the quality of life questionnaire
after every time they use cannabis; the participants can use cannabis three times daily for a year,
and will have an initial and final questionnaire making the maximum total of questionnaire for
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each participant being 1,097. The mean scores of the questionnaires will be compared between
the experienced and non-experienced cannabis users. The standard deviation for both the
experienced cannabis users and non-experienced cannabis users will be calculated. The mean
size of tumor growth during the yearlong study will also be calculated along with its standard
deviation.
Independent t-test will be used to examine the mean scores on the quality of life
questionnaire. It will compare the mean score of the two independent variables; experienced
cannabis users and non-experienced cannabis users. The mean of the scores on the questionnaire
are presented in Figure 1. The alpha level for this test will be .05. For the hypothesis to be
supported the t-test would reveal a statistically significant difference between the means of
scores for experienced cannabis users (M =XX, SD =XX) and non-experienced cannabis users
(M =XX, SD =XX), t(99) = X.XX, p < .05. This shows that experienced cannabis users score
significantly lower on quality of life test then non-experienced cannabis users.
In order to examine the hypothesis that participants will have reduced tumor growth we
will be calculating the change for the overall sample between pre and post-test assessments .We
will perform a dependent groups t-test that will compare the size of tumors growth shown (M
=XX, SD =XX) on a CAT scan starting at the initial doctors appointment then taken until the
following year. The alpha level for this test will be .05. The test would be statistically significant
if the tumor growth stops or reduces in size, t (99) = XX.XX, p < .05. This shows overall
participants tumor growth have stopped or decreased when using the cannabis treatment.
Discussion
The goal of the present study will be to determine if cannabis improves cancer patients’
quality of life and also reduces or stops tumor growth. There are two groups of cannabis users;
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experienced and non-experienced, who will take a quality of life questionnaire after every time
they use cannabis for a specified reason. The participants’ tumor growth will also be monitored
once a month. Expected results will show that experienced cannabis users will score lower on the
quality of life questionnaire with non-experienced cannabis users scoring higher on the quality of
life questionnaire, and both experienced and non-experienced cannabis users will show decrease
or a stop in tumor growth. The expected results support the hypothesis that experienced cannabis
users will score lower on the questionnaire and participates will have decreased tumor growth.
This present study is different from previous studies because not only is the cannabis
vaporized but also it focuses on cancer patients’ quality of life, and uses a specifically designed
questionnaire carefully made to accurately measure the changes in quality of life for the
participants over time while using cannabis as a treatment to improve quality of life. This study
is also different because it also focused on tumor growth, which is being measured along with
quality of life. These differences add to previous research because it shows that cannabis can be
used for multiple treatments at the same time. The findings in this study will have the same
finding as previous research. Guzmán found that cannabis has a palliative effect on patients with
cancer (2003). These finding are the same as what will be found from measuring the quality of
life questionnaire showing cannabis has a relaxing effect on participants helping to reduce pain.
This shows that cannabis is a positive treatment to give cancer patients who experience pain and
need help to comfortably relax. In another previous study it was found that persons who have
previously used cannabis have better responses to smoked cannabis (Voth & Schwartz, 1997).
This also agrees with the findings of the quality of life questionnaire because experienced
cannabis users score lower due to less side effects to using cannabis. This is a positive finding
because this can give doctors a new outlook to using cannabis as a treatment for patients who
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have previous experience using cannabis knowing these patients will have less side effects and a
better response to this treatment.
This study shows strength, one being the study design. The study is experimental and
longitudinal, using repeated measures and independent groups. Using repeated measures allows
each group to be a control for itself and keeps an up to date record of how the participants are
reacting to the giving treatment. Another strength of this study is the sample size, having 100
participants is a large sample size, which enables the experimenter to have more power.
This study does also show some limitations. The first being there is no control group to
compare the results to, this makes its difficult to tell if the cannabis is the only reason quality of
life has increased and tumor growth has decreased. Another limitations this present study has are
the questionnaire used. The quality of life questionnaire is a questionnaire that the experimenter
has designed for this study and has used once when running a pilot study, making the
questionnaire not a commonly and well-used measure to find participants quality of life.
Founded by the expected results, the final conclusion is cannabis is a positive treatment
to increase cancer patient’s quality of life and decrease tumor growth. Because cannabis will be
shown to be effective for increasing patients quality of life doctors can now use this as a more
commonly prescribed method to help treat cancer patients to minimize negative side effects of
cancer and cancer treatments such as pain, appetite loss, and/or exhaustion. This finding could
also lead to more states allowing cannabis to be a treatment that is legally accepted. This can also
change people’s minds that have a negative outlook towards cannabis. These findings could also
introduce treatments for other illness that have common side effects as cancer making this a
more diverse treatment. Cannabis as a treatment can be used in many settings when used through
a vaporizer because it is not harmful for the people around you so it could be used in homes,
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hospitals, and other places that allow smoking. For future research in this field of treatment
control groups would be beneficial to compare the cannabis to a placebo. Studies can also
research how cannabis is effective for others illness. Also finding a way to make cannabis a less
habit-forming treatment would be beneficial to patients. Overall cannabis is shown to be a
positive medical treatment for cancer patients with both tumors and side effects from cancer
treatments by improving patient’s quality of life and stopping or decreasing tumor growth. With
more studies and a growing acceptance of cannabis the medicinal use for it could include a
variety of different uses. This is one treatment that still has a lot to be learned about but can be
very helpful to many people in the future.
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References
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745-755. doi:10.1038/nrc1188
Hermanson, D., & Marnett, L. (2011). Cannabinoids, endocannabinoid, and cancer.
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Huskey, A. (2006). Cannabinoids in Cancer Pain Management. Journal Of Pain &
Palliative Care Pharmacotherapy, 20(3), 43-46. doi:10.1300/J354v20n03_11
Kogan, N. M. (2005). Cannabinoids and Cancer. Mini Reviews In Medicinal Chemistry,
5(10), 941-952. doi:10.2174/138955705774329555
Voth, E. A., & Schwartz, R. H. (1997). Medicinal Applications of Delta-9Tetrahydrocannabinol and Marijuana. Annals Of Internal Medicine, 126(10), 791798.
Walsh, D., Nelson, K., & Mahmoud, F. (2003). Established and potential therapeutic
applications of cannabinoids in oncology. Supportive Care In Cancer: Official
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137-143.
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Figure 1. Mean scores on Quality of Life Questionnaire for Cancer Patients. Experienced
cannabis users scored lower on the Quality of Life Questionnaire than non-experienced cannabis
users.