Many solid tumors carry genetic changes targeted by existing compounds

May 31, 2013, Fox Chase Cancer Center

Nearly two-thirds of solid tumors carry at least one mutation that may be targeted, or medicated, by an existing compound, according to new findings from researchers Fox Chase Cancer Center that will be presented at the 49th Annual Meeting of the American Society of Clinical Oncology on June 3. The results suggest that it may one day become commonplace for doctors to sequence tumors before deciding on a treatment regimen.

"Extended sequencing of a patient's tumor is not something that's routinely done now," says study author Patrick Boland, MD, a /oncology fellow at Fox Chase. "Our ultimate hope is that, if we determine testing is worthwhile, it becomes routine for a doctor to send off a tumor sample to look for before deciding on a course of treatment."

In some forms of cancer, such as , doctors do check for a limited number of mutations. Mutations found with this focused testing only affect the treatment of a small proportion of patients. However, most tumors likely have many mutations, some of which may be targeted specifically by drugs already on the market, or under development.

To investigate, 77 patients with solid tumors—primarily and — underwent genetic profiling looking for nearly 200 mutations associated with cancer. Boland and his co-author Alan Skarbnik reviewed the DNA sequencing to analyze the net results of testing and consider the potential impact on .

Most of the patients—96%—carried one mutation or more. Nearly two-thirds had at least one mutation the researchers termed "actionable," meaning it is targeted by a drug that is on the market or in development. Many of the mutations were amplifications, in which multiple copies of a single gene were present, which ramps up its effect on the body.

Boland stresses that even though these are present, in many cases it's not clear which ones – if any – are driving the cancers. "Even if we find a [change], we don't know if it's something that's driving the tumor to grow, or something that just happened along the way." The results from this study highlight the need for more research to understand the basic biology of tumors, he notes. "We need our colleagues in the basic sciences to continue investigating the genetic underpinnings of cancer, so we can determine which mutations are most important to target."

The sequenced data was reviewed by the patients' doctors, and in some cases, they prescribed new medications that targeted the identified mutations. Even though patients had all tried—and failed—treatments in the past, some responded well to the new medicine, including one patient who has been on the treatment for at least 6 months.

A major limiting factor in sequencing all tumors, says Boland, is cost—the list price of the sequencing test used in the study, from the company Foundation Medicine, is nearly $6,000. "We hope that, once sequencing tumors becomes the standard of care, it will be routinely covered by insurance."

Indeed, genetic sequencing is getting more affordable, notes Boland. Once tumor DNA can be analyzed readily, doctors learn more regarding how to use that information to guide treatment, and patients get more access to medicines that target these mutations which may be beneficial. It may become commonplace for most doctors to sequence tumors before deciding how to treat them. "The expectation is that, sometime soon, these kinds of tests will be done on a routine basis," predicts Boland. "We're not there yet."

Explore further: Tumors with ALK rearrangements can harbor more mutations

Related Stories

Tumors with ALK rearrangements can harbor more mutations

April 22, 2013
The identification of potentially targetable kinase mutations has been an exciting advancement in lung cancer treatment. Although the mutations driving many lung carcinomas remain unknown, approximately 50 percent of lung ...

Researchers identify genetic mutation for rare cancer

January 15, 2013
By looking at the entire DNA from this one patient's tumor, researchers have found a genetic anomaly that provides an important clue to improving how this cancer is diagnosed and treated.

Genetic diversity within tumors predicts outcome in head and neck cancer

May 20, 2013
A new measure of the heterogeneity – the variety of genetic mutations – of cells within a tumor appears to predict treatment outcomes of patients with the most common type of head and neck cancer. In the May 20 issue ...

First prospective trial shows molecular profiling timely for tailoring therapy

May 15, 2013
A clinical trial has shown that patients, and their physicians, are eager to jump into next-era cancer care—analysis of an individual's tumor to find and target genetic mutations that drive the cancer. Results of the study, ...

Researchers narrow the search for biomarkers of drug resistance in head and neck cancer patients

May 31, 2013
Researchers from Fox Chase Cancer Center will present data at the 49th Annual Meeting of the American Society of Clinical Oncology on Saturday, June 1, which shows the discovery of potential biomarkers that may be used to ...

Patients with BRCA1 mutations, but not BRCA2 mutations, had poorer prognosis compared with noncarriers

April 9, 2013
Patients with breast cancer who had a BRCA1 mutation had significantly worse overall and recurrence-free survival rates compared with patients without BRCA mutations, but no evidence for a difference in survival was found ...

Recommended for you

Some brain tumors may respond to immunotherapy, new study suggests

December 10, 2018
Immunotherapy has proved effective in treating a number of cancers, but brain tumors have remained stubbornly resistant. Now, a new study suggests that a slow-growing brain tumor arising in patients affected by neurofibromatosis ...

Study finds higher risk of breast cancer for women after giving birth

December 10, 2018
Younger women who have recently had a child may have a higher risk of breast cancer than their peers of the same age who do not have children, according to a large-scale analysis co-led by a University of North Carolina Lineberger ...

A code for reprogramming immune sentinels

December 10, 2018
For the first time, a research team at Lund University in Sweden has successfully reprogrammed mouse and human skin cells into immune cells called dendritic cells. The process is quick and effective, representing a pioneering ...

Researchers develop personalized medicine tool for inherited colorectal cancer syndrome

December 10, 2018
An international team of researchers led by Huntsman Cancer Institute (HCI) at the University of Utah (U of U) has developed, calibrated, and validated a novel tool for identifying the genetic changes in Lynch syndrome genes ...

Study shows key enzyme linked to therapy resistance in deadly lung cancer

December 10, 2018
Researchers at The University of Texas MD Anderson Cancer Center have identified a link between an enzyme tied to cancer formation and therapy resistance in patients with epidermal growth factor receptor (EGFR)-mutant non-small ...

Potential seen for tailoring treatment for acute myeloid leukemia

December 8, 2018
Advances in rapid screening of leukemia cells for drug susceptibility and resistance are bringing scientists closer to patient-tailored treatment for acute myeloid leukemia (AML).

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.