Pill that sent cancer into remission may be 'a one-off,' doc says
Published Thursday, March 12, 2015 10:31AM EDT
Last Updated Thursday, March 12, 2015 2:09PM EDT
The case of a B.C. woman whose Stage 4 colorectal cancer went into remission after she took a blood pressure medication may be causing a stir, but her doctor says researchers are a long way from replicating the unexpected turnaround.
Last fall, retired costume designer Trish Keating, 67, joined a clinical trial with the B.C. Cancer Agency in Vancouver to run genomic tests on her colon cancer. When tests revealed that a specific protein was acting as the driving force behind her cancer, she was put on a blood pressure medication that blocks the protein. Within five weeks, tests found her cancer was barely detectable.
Keating's doctor, Dr. Howard Lim, a medical oncologist with the B.C. Cancer Agency, says it's wonderful to see Keating's cancer in remission, but notes there are still many unanswered questions.
"Right now, this is really quite exciting for Trish but to be quite frank, we do need to take a step back and (ask) is this still durable? How long will this last? Those are the questions we don't know yet," Lim told CTV's Canada AM Thursday from Vancouver.
"And that's why Trish and I are taking this day by day."
Keating’s treatment was part of a clinical trial into the evolving field of personalized oncogenomics, or POG. It involves sequencing the genome of cancer tumours to try to identify potential treatments, says Lim.
"What we're trying to do is figure out the blueprint of someone's cancer -- what are the driver pathways that causes someone's cancer to grow? -- and then tailor treatment toward someone's cancer," he said.
But, he stressed, researchers have a long way to go.
"It's not an exact science and that's why it's still highly experimental."
Lim notes that Keating was an "outlier" and her cancer is rather unique. His team is still going through their genomics database to see who else might benefit from the same treatment, and potentially develop a clinical trial.
But in most cases, he says, genomic testing reveals that standard chemotherapy drugs are the best option.
Keating was told she could try a chemo drug or one of two blood pressure drugs. She didn't want to do chemo again, so went with the blood pressure drug, which turned out to be successful -- to the surprise of everyone.
"This is a one-off, or what we would call 'n=1' in a case report. We're still trying to figure out why, in particular, this has worked so well," Lim said.
Lim's team has not revealed the name of the blood pressure medication they used until a study of her case is published in a peer-reviewed medical journal.
The study has seen several other "extraordinary experiences" among other patients trying other treatments, Lim says. They've also had a few misses, in which suggested therapies failed to work.
Nevertheless, Lim believes says this form of personalized medicine is the future of cancer treatment, and says several cancer agencies besides his are doing their own research into oncogenomics.
Similar research is being done in cardiology too, to help doctors make better decisions about which heart medications will work for which patients.
Beyond the fact that oncogenomics is still highly experimental, it's also fairly laborious and expensive, Lim points out. It takes about two to three months to complete a genome analysis at a cost of about $25,000 per patient.
He says that, since Keating's story went public, he's been getting 10 to 20 patients a day contacting him asking for the same treatment, but he says he has to remind them to wait, as the approach is still experimental.