Novel testing defines the future of prostate and colon cancer

Friday, April 12, 2013
Professor Bapat
LMP Professor Bharati Bapat in her lab at Mount Sinai Hospital.

Can prostate and colorectal cancer patients receive earlier and more accurate diagnoses and can some of these patients avoid unnecessary treatment? These questions are at the core of innovative research being conducted by the Department of Laboratory Medicine and Pathobiology’s (LMP) Professor Bharati Bapat.

With the goal of providing customized patient care, Prof. Bapat is using genetic and epigenetic (changes in gene function that do not disrupt the underlying DNA sequence) approaches to study groups of patients who have prostate, colorectal, bladder and kidney cancer. Using tissue, urine and blood samples from these patients, her lab is focused on discovering specific gene signatures called biomarkers. These biomarkers allow Prof. Bapat to understand the specific roles of the genes in normal and cancerous cells and can help identify the aggressiveness of these types of cancers.

One of her primary areas of research is in prostate cancer: a disease that accounts for 27 per cent of all new cancer cases in men in Canada. While the current prostate-specific antigen (PSA) test is widely used for screening this type of cancer, it is not ideal because it may provide false-positive or false-negative test results. To provide more accurate diagnoses, Prof. Bapat is studying DNA methylation biomarkers. These biomarkers can be easily detected in urine and could eliminate the need for unnecessary, invasive tumour biopsies.

To pursue this essential research, Prof. Bapat was given the Movember GAP1 research award for the Global Prostate Cancer Biomarker Initiative in 2012. The goal of this international initiative is to better predict aggressive prostate cancer and provide individualized patient care. The initiative provides Prof. Bapat valuable access to blood and urine samples from the United Kingdom. When they are combined with Canadian samples from University Health Network’s BioBank and Sunnybrook Health Sciences Centre, she has a powerful platform to study these biomarkers. 

Along with prostate cancer, her other main area of research is in colorectal cancer. Using samples recruited from six international registries, she is interested in defining biomarkers that are related to distinct subtypes of colon cancer. She is also currently working with The International Society for Gastrointestinal Hereditary Tumours Incorporated (InSiGHT) to create a comprehensive categorization system that collects and analyzes previously undefined genetic changes in patients’ blood samples and tumours.

“The InSiGHT initiative is a good example of how these global initiatives can be used for more than one disease. Even though we’re studying colon cancer genes, the same strategy can be used for any other genes and applied to cancer and to other diseases,” says Prof. Bapat. “It’s similar with our research focus on the (epi)genetic markers for prostate cancer. We’re studying urine biomarkers, but you can envision that the same non-invasive strategy could be used to look for biomarkers in stool for colon cancer patients.”

The success of this research relies on local, national and international collaboration. “These kinds of studies can only be done in a multidisciplinary environment where you work with different experts who contribute their unique perspectives,” says Dr. Bapat. “We work with urologists, pathologists, oncologists, surgeons and other basic scientists - it’s important to get perspectives from both the clinical and the laboratory side.”

Prof. Bapat’s second-year PhD Candidate, Darko Zdravic points out, “I feel privileged to have the opportunity to pursue my PhD with Dr. Bapat at the University of Toronto’s Department of Laboratory Medicine and Pathobiology. Working on this translational prostate cancer biomarker research project has allowed me to gain exposure to the clinical as well as laboratory setting. I have gained a newfound appreciation for the gravity of the clinical problems that we’re trying to address.”

As an expert in her field, and as an LMP faculty member since 2000, Prof. Bapat’s passion for her research is clear. “By addressing clinical problems in the laboratory setting, I’m interested in improving patient care and alleviating anxiety for patients and their families through our research,” she says. “I also like to see how students get inspired and motivated by these projects and it’s really exciting to train the next generation of researchers and physician-scientists.”