Mesothelioma Research Program Update 2007
Over the past year, the University Health Network/The Princess Margaret Hospital Foundation have made progress in its Mesothelioma Research Program. Following are a number of distinct, but inter-related projects encompassed within the program. Progress in each of these areas will be summarized individually.
THE EARLY DETECTION PROJECT
This research study was launched in March 2005 under the leadership of radiologist, Dr. Heidi Roberts, and continues under the guidance of her colleague, Dr. Demetris Patsios. Brenda O’Sullivan is the project coordinator. The aim is to screen people who have either a strong history or chest x-ray evidence of asbestos exposure. Presently, the group is primarily interested in the early detection of mesothelioma and lung cancer. In the future, it plans on screening for other asbestos related lung diseases.
Each person enrolled in the study undergoes an in-depth interview questionnaire focusing on asbestos exposure history and other possible contributing factors. A small sample of blood is then obtained for use in associated studies aimed at the early detection of mesothelioma (see below for a description of some of these studies). Each participant then undergoes a Low Dose Computer Tomography (CT) scan of the chest.
The scan is read by a chest radiologist and a report generated, which is sent to the participant’s family physician. Depending on what is found on the scan, the participant is asked to return for further scans at regular intervals. If there is concern of an abnormal finding, further diagnostic studies are arranged. So far, two cases of mesothelioma and three lung cancers have been discovered and treated in over 400 study participants. The group is continuing to actively recruit individuals to this study from high risk occupations.
IDENTIFYING RISK FACTORS IN MESOTHELIOMA PATIENTS
Drs. Geoffrey Liu and Ming Tsao, two physicians and scientists at the Ontario Cancer Institute and Princess Margaret Hospital, are working to identify the genetic and environmental factors that lead to the development of mesothelioma. Many people are exposed to asbestos. Yet, only a small proportion develop mesothelioma. These scientists are studying the interaction between asbestos exposure (such as the amount of exposure and the type of asbestos) and genetic (inherited) factors that determine how the body responds to asbestos. In addition, genetics may play a role in how well a person does after their mesothelioma is treated. So studies are underway to determine the genetic factors associated with a patient’s response to drug therapy, while other studies are focused on developing animal models of human mesothelioma to better understand the basic mechanisms of this cancer. By understanding these basic factors about mesothelioma, the researchers hope they can identify new treatments for this deadly disease.
BLOOD TESTS FOR THE EARLY DETECTION OF MESOTHELIOMA
Blood tumour markers, which are proteins associated with tumours, are frequently used to help diagnose various cancers, to follow response to treatment and to help diagnose cancer early. Dr. Marc de Perrot, a surgeon scientist at Princess Margaret Hospital and the University Health Network, is currently investigating mesothelin and osteopontin, two mesothelioma markets, to detect early disease in populations exposed to asbestos. Combining these tumour markets with screening CT scans may provide an even earlier detection of mesothelioma than CT scans alone. The screening program should therefore lead to more patients being diagnosed at an earlier stage of the disease, which gives them greater hope for a cure. Furthermore, these markers can be used to detect recurrence of the disease as well as measure the effectiveness of treatment.
DEVELOPMENT OF IMMUNOMODULATION THERAPY
The human immune system plays a key role in fighting off various types of diseases, including cancer. Recently, Dr. de Perrot and fellow researcher, Dr. Masaki Anraku, discovered that the presence of certain immune cells in humans called CD8+ lymphocytes are associated with better outcome in mesothelioma patients. The stimulation of these immune cells (immunomodulation) can therefore become a potential treatment.
The research group is currently investigating these special lymphocytes in an animal model of mesothelioma to measure how well they kill tumour cells. Combination of immunomodulation therapy with current standard treatment provides hope for a better outcome for mesothelioma patients.
ONGOING TREATMENT STUDIES FOR PATIENTS WITH MESOTHELIOMA
Every person diagnosed with mesothelioma should undergo a thorough investigation and be offered appropriate treatment. Depending on the extent of disease and the general health of the patient, this treatment may vary all the way from an aggressive attempt to cure to a means of controlling symptoms and making the person comfortable. The Tri-modality Study, a combination of chemotherapy, surgery and radiation, patients with early stage mesothelioma continues at Princess Margaret Hospital and will soon be offered at other locations in Canada.
DR. MICHAEL JOHNSTON HAS MOVED TO HALIFAX
The leader of the Mesothelioma Research Program, Dr. Michael Johnston, has moved his clinical practice to the Nova Scotia Cancer Centre/QE II Medical Centre in Halifax, where he is a professor of Surgery at Dalhousie University.
His medical research, including maintaining leadership of the Mesothelioma Research Program, however, remains at the Princess Margaret Hospital in Toronto. In the near future the research group plans on offering many of the same research projects presently available in Toronto to people in the Maritimes.
Support for the mesothelioma research program is provided by the International Association of Heat and Frost Insulators and Asbestos Workers Local 95 of Ontario; International Association of Heat and Frost Insulators and Asbestos Workers (U.S.); Master Insulators Association of Ontario; United Association of Plumbing and Pipe Fitting Local 46; Sarnia Occupational Health Clinic for Ontario Workers; Loretta’s Legacy Foundation; Motley Rice LLC; and many others.
