Targeted cancer treatments better traditional methods

MIAMI: Cancer treatments that attack tumors based on their individual genetic traits-not their location in the body-far outperform traditional methods, extending survival for twice as many patients, a study said yesterday. The precision medicine field of targeted therapy involves testing tumors for clues about their genetic mutations, and matching patients with new drugs designed to block cancer’s growth on a molecular level.

Researchers in Texas began studying the impact of these therapies in 2007, after seeing the success of Gleevec (imatinib) — a breakthrough drug approved by US regulators in 2001 that showed huge success against chronic myeloid leukemia. The results of the first and largest precision medicine trial to look at survival across a host of cancer types and many different targeted therapies were released at the American Society of Clinical Oncology meeting in Chicago, the world’s largest annual cancer meeting.

The study, called IMPACT, enrolled 3,743 patients at Texas MD Anderson Cancer Center from 2007 to 2013. All the patients had advanced cancers, or “end-stage disease,” involving cancers of the gastrointestinal tract, breast, or lung. Melanoma and cancer of the female reproductive tract were also included, along with more rare types of cancer.

Those enrolled had typically tried at least four-and sometimes up to 16 other treatments that failed to halt the growth of their cancer. Patients who received molecular targeted therapies either got an investigational drug then being tested in a clinical trial, or an FDA-approved targeted therapy commercially approved for another indication.

After three years, 15 percent of people treated with targeted cancer therapies were alive, compared to seven percent in the nontargeted group. After 10 years, six percent of the targeted group was alive, compared to just one percent in the other group.

Still far from a cure

On the whole, targeted therapies led to an average of four months of life without the cancer advancing, known as progression-free survival, and nine extra months of overall survival. Those who were treated with traditional approaches lived just under three months without cancer growing, and 7.3 months longer overall. Researchers say the field has grown immensely since 2007, and that further research will improve the range of therapies available to cancer patients.

“When IMPACT first opened, we tested for no more than one to two genes,” said lead investigator Apostolia Tsimberidou, professor of investigational cancer therapeutics at MD Anderson. “Now patients are being tested for hundreds of actionable genes, amplifications and mutations, as well as for immune markers,” she added. “Ideally, in the future, patients’ tumor testing and cell-free DNA analysis will become the standard of care at the time of diagnosis, in hopes of making a difference for patients upfront, especially in those with hard-to-treat cancers.”

Colon cancer treatment costs more in US In related news, people diagnosed with advanced colon cancer pay twice more per month for treatment in the United States than in Canada, but do not live any longer, researchers said Friday. Canadian residents of British Columbia paid an average of $6,195 per month, compared to patients in the northwestern US state of Washington who paid $12,345, said the study released at the American Society of Clinical Oncology (ASCO) conference in Chicago. The two regions are about 700 miles (1,100 kilometers) apart, have similar income levels, and a racial makeup that is mainly white with a significant Asian minority. Canada has a single payer heath system, while the United States has a mix of private insurance and government-funded health insurance.

“To our knowledge, this is the first study to directly compare treatment cost and use, along with health outcomes, in two similar populations treated in different health care models,” said lead author Todd Yezefski, a senior fellow at the Fred Hutchison Cancer Research Center in Seattle, Washington. The findings “may help us improve care and potentially lower health care costs,” he added. The study tracked 1,622 patients with metastatic colorectal cancer in British Columbia and 575 in Washington state. The median age of the patients in Canada was 66, while in the United States it was 60.

More patients in the US (79 percent of those diagnosed) than in Canada (68 percent) opted to undergo the most aggressive treatment available. Both groups were treated with similar kinds of chemotherapy. Despite paying about twice as much, US patients lived an average of 21.4 months after diagnosis. Canadian patients lived an average of 22.1 months. Among those who decided not to pursue treatment, the average survival was 5.4 months in Washington and 6.3 months in British Columbia.

“As oncologists, we see the burden of high costs on patients and their families every day,” said ASCO chief medical officer Richard Schilsky. “This study adds important context to the ongoing national conversation about rising treatment costs.”