Young Talent at the Queen's Cancer Research Institute
Dr. Chris Booth
Cancer Care and Epidemiology
It’s natural to assume that a cancer drug or treatment that survives clinical trials and enters routine practice will perform as it did during the trials. But that’s not always the case – and there are good reasons why.
To be part of a clinical trial, patients must have the disease or condition that the trial treatment is designed to address, but otherwise they are usually reasonably fit, young, active, and free of other diseases that might complicate the interpretation of trial results. As well, trial patients are treated by specialists at state-of-the-art cancer hospitals. In other words, the strict eligibility criteria that apply to clinical trial subjects don’t necessarily apply to everyday patients, who more often than not are elderly, have multiple illnesses and are treated in hospitals big and small.
“Results of clinical trials reflect what happens when a new drug is given to ‘Olympic’ patients, by ‘Olympic’ doctors and nurses in ‘Olympic centres,’” says Dr. Chris Booth, a medical oncologist and associate professor at Queen’s. “But what happens when you take potentially toxic medications that have been given to these ‘Olympians’ in tightly-controlled situations and treat thousands of patients who are older, sicker, with other co-morbidities, and who are treated by real doctors in the real world?”
To answer this question, Booth analyzes data in the Ontario Cancer Registry and provincial treatment records, a massive repository of population-based data about every cancer patient in Ontario. It contains decades’ worth of anonymous information about cancer type, the patient’s age, treatment, long-term survival, geographic location and a host of other factors that together paint a vivid picture of cancer care and outcomes in Ontario. For cancer health services researchers like Booth, the registry is a gold mine of information that can offer vital clues about changes in cancer incidence, how it is being treated, whether there are gaps in care that need to be addressed as well as patient outcomes achieved in the “real world.” Another Queen’s professor of oncology, Dr. Bill Mackillop, pioneered the use of the Ontario Cancer Registry for health services and outcomes research in the early 1990s, and successfully lobbied for Ontario’s chemotherapy and radiation treatment records to be made available for research.
One way Booth’s work has made a difference involves an investigation on the use of adjuvant chemotherapy in patients who have had surgery for lung cancer. An international clinical trial led by the NCIC Clinical Trials Group and published in 2004 showed that adjuvant therapy improved the survival rates of lung cancer patients by as much as 15 percent. It was a landmark finding that, almost immediately, changed treatment recommendations worldwide. Subsequent research by Booth and colleagues showed that “real world” patients treated in Ontario derived a survival benefit very close to that seen in the clinical trial. But while use of adjuvant therapy for lung cancer increased after 2004, the increase was not as much as expected. The study also revealed that some cancer hospitals in the province used adjuvant therapy more often than others – thus opening the door for further improvement in care and better outcomes for patients with lung cancer in Ontario.
“Society invests a huge amount of time and money towards finding new treatments for cancer,” says Booth, “but if we invest some of those resources to ensure that doctors do some of the things that we already know work, the population health benefits would be enormous.”
(e)Affect Issue 5, Spring 2014