According to a study published in the journal Radiology, researchers from Cancer Research UK’s Cambridge Experimental Cancer Medicine Center at the University of Cambridge, have determined that the best method to monitor how women with late-stage ovarian cancer are responding to treatment may be a magnetic resonance imaging (MRI) technique. The technique measures the movement of water molecules within the tumor.
After comparing three different MRI techniques, the team found that a “diffusion-weighted MRI” is the most effective at distinguishing when tumors that had spread from the ovaries into nearby tissues were not responding, and at indicating response to treatment.
Although CT scans are frequently used to help determine whether individuals with ovarian cancer should continue having chemotherapy after their first round of treatment, they can only detect changes in the size of the tumor, not differences in its structure.
Lead researcher of the study, Dr. Evis Sala from the University of Cambridge, explained:
“At the moment we rely on CT scans and blood tests to tell us what’s going on inside a patient’s tumor. But it’s difficult to judge how effective treatment has been from these alone, particularly when the cancer has spread to other tissues where it may behave differently to the primary tumor.
We’ve shown that diffusion-weighted MRI can give a much better idea of the density of tumors, in addition to their size, making it easier to determine which patients are benefitting most from the treatment. We are now collaborating on a nationwide study to see if this type of imaging could be an effective way of predicting treatment response in a much larger group of patients with advanced ovarian cancer.”
One of the 21 women who participated in the study is Daphne Tustian, who was diagnosed in May 2009 with advanced ovarian cancer. During the study, different MRI techniques were used to monitor her throughout her chemotherapy in order to help inform doctors how her treatment was going. In November 2009, Tustian’s cancer went into remission, although it returned just over one year later.
Tustian said:
“I know that at present doctors are trying to prolong my life – they are unable to cure the cancer in my body, but if they can give me more time with my family I am very happy with that.
When I enrolled on the trial, nurses explained to me that it may not benefit me directly but certainly would help others in the future.
I do feel that I have benefitted from the trial, however, as I was closely monitored and each at each stage how my cancer was responding to treatment. It saved me from having unnecessary chemotherapy and it can save other too. If someone is on chemotherapy and it’s not working it’s a waste of their time, of drugs, of money and a waste of life.”
All study participants received an MRI of the pelvis and abdomen, they also underwent 3 additional MRI techniques on top of the standard scans. The researchers compared the various imaging methods using different parameters, including Apparent Diffusion Coefficient (ADC), which measures the movement of water molecules in tumors.
After comparing the ADC measurements in the main tumor as well as in cancer cells that had metastasized from the ovaries into the abdominal lining, the researchers discovered that among individuals who responded to treatment, there was a larger increase in the ADC of the primary tumor, than patients who didn’t respond to treatment. In addition, they found no change in the in the sites of cancer spread.
Dr. James Brenton from Cancer Research UK’s Cambridge Research Institute, and senior author of the study, said:
“The increases in ADC seen in the primary tumor in patients who responded to treatment is due to the chemotherapy killing some of the cancer cells, which in turn increases the amount of space inside the tumor allowing water molecules to flow more easily.
The fact that there was little change in sites of cancer spread suggests that these cells may be more resistant and so need to be targeted with a different treatment to the primary tumor.”
Dr. Joanna Reynolds, Cancer Research UK’s director of centers, explained:
“A important aim of Cancer Research UK’s Experimental Cancer Medicine Network is to support the development of tests that can help doctors to quickly spot treatment resistant cells in the tumor, so therapy can be tailored appropriately.
Advanced ovarian cancer can be very difficult to treat, meaning it’s vital that patients are monitored closely to ensure they are benefitting from treatment. We’re excited to be funding the next stage of this research, which will look at the potential benefits of this test in a much larger group of patients.”
Written by Grace Rattue