Trial Information

A Multi-modality Imaging Assessment of Chemobrain

In this study, 3 groups of 8 women each, between the ages of 18 and 65, will participate in
this study. The "affected patient group" will be women with complaints of memory dysfunction
who have received adjuvant chemotherapy (one or more anticancer drugs used in combination
with surgery), for the treatment of breast cancer. These patients will be those that are
being treated at Huntsman Cancer Institute/Hospital.

The second "patient control group" will be age-matched (same age) women with breast cancer
who have undergone similar chemotherapy and have no complaints of memory problems.

The non-patient group will be age-matched (same age) women who have not undergone any type
of chemotherapy. These individuals will be recruited from friends of female family members
of the two breast cancer groups.

All individuals will be assessed for dementia (intellectual deterioration) and brain
problems using the same kind of neuropsychological testing. All subjects will be age-matched
as close as possible, to eliminate age related effects. Subjects will be right-handed,
primarily-English speakers with normal hearing.

The purpose of this study is to use modern imaging techniques to better understand
chemobrain. These imaging techniques include FDG-PET (FDG is the abbreviation for the
radiopharmaceutical fluorodeoxyglucose and PET is Positron Emission Tomography) and
functional MRI (fMRI)). They will be used to look at the metabolism (chemical activity) in
specific areas of the brain and the entire brain overall. By using FDG-PET doctors will see
how the brain activates. By using fMRI doctors will see how the brain works when you are
challenged with certain mental tasks that make you concentrate and remember. FDG-PET and
fMRI might provide important information on the brain that may be connected with
chemotherapy.

This study will be an important first step to understand the problem of chemobrain. The
imaging evaluations will make it possible to explore the changes in brain function that may
be responsible for chemobrain and hopefully make it possible to predict which people may be
affected by this problem.

Many people who undergo chemotherapy particularly adjuvant chemotherapy have complained
about cognitive dysfunction for many years. This cognitive decline effects up to 16 -50% of
individuals receiving long-term adjuvant chemotherapy [Tannock 2004, Matsuda 2005].Cancer
survivors frequently refer to this cognitive dysfunction as "chemobrain" or "chemofog." The
majority of individuals who are affected are woman who have undergone adjuvant chemotherapy
for breast cancer. The table below is a summary of many of the studies that have been
performed assessing cognition and chemobrain.

Women who experience chemobrain typically complain of inability to concentrate, memory
dysfunction, word finding difficulties, difficulty with learning, slowed processing
abilities, and often difficulty with writing and speaking. A particularly disturbing
complaint for many individuals is the inability to multitask. Only recently, have
researchers begun studying the impact of chemotherapy on cognitive functioning. This is a
difficult area to study however. Part of the problem in assessing chemobrain using
scientific principals is sorting out which problems are due to chemotherapy and which are
due to having a serious illness like cancer that can result in physical debilitation,
depression, sleep disruption, hormone shifts, and fatigue--all of which can affect cognitive
functioning.

There are a number of theories at to why chemobrain may occur. One is that some types of
chemotherapy can cross the blood/brain barrier and cause neurotoxicity. Another is that the
cognitive problems are created by certain free radicals, the toxic elements that many types
of chemotherapy produce [Joshi 2005]. Another theory is that some people have a genetic
background that makes them more susceptible to the effects of chemotherapy. Most likely it
is not just a single etiologic factor but a multifactorial process that combine to
predispose certain individuals to develop chemobrain. Chemotherapy isn't the only cancer
treatment that may cause cognitive disturbance and memory complaints. Other cancer
treatments that have been implicated as causing complaints of cognitive dysfunction include
hormone therapy, immunotherapy, and radiation therapy. Hormone therapy is common in woman
being treated with conventional chemotherapy. It is not entirely clear if women undergoing
hormone therapy which alters the amount of systemic estrogen experience memory problems.
Some studies link memory to the amount of estrogen in the brain. Other studies haven't found
this link.