Precision Medicine Treatments Improve Cancer Patient Outcomes

Patients with advanced cancer who received precision medicine treatments were more likely to survive or have longer periods without their disease progressing than those who received standard therapies, according to a study published in Nature Communications.

Next-generation sequencing can help identify novel cancer targets, but interpreting molecular findings and accessing appropriate drugs or clinical trials can be challenging, the researchers noted.

To implement a precision medicine strategy, a team at UC San Diego Health established a multidisciplinary molecular tumor board (MTB) to advise treating physicians on course of care.

The board included a project manager to facilitate obtaining clinical biomarkers, as well as medication-acquisition specialists who would help design precision medicine strategies based on individual patients’ molecular tumor makeup. The MTB served as an advisory board, with the final decision made by the patient’s physician.

Of 429 patients evaluated by the MTB, 62 percent were matched to at least one drug. Twenty percent of patients matched to all recommended drugs, including combination therapies. In 38 percent of cases, the treating physician chose not to use the board’s recommended strategy, and instead opted for a standard therapy approach that may have been unmatched to the patient’s genetic alterations or had a low degree of matching.

The results showed that patients who received the entire regimen recommended by the MTB had significantly improved progression-free survival and overall survival when compared to patients who received the physicians’ choice treatment.

The three-year survival for patients with the highest degree of matching and who received a personalized cancer therapy was approximately 55 percent compared to 25 percent in patients who received therapy that was unmatched or had low degrees of matching.

“Overall, our MTB experience suggests that greater degrees of matching of tumors to drugs, including with customized N-of-one recommended combinations, was independently associated with better outcomes,” researchers stated.

While the approach showed potential for improving cancer patient outcomes, the researchers noted that there are several obstacles to implementing MTBs in healthcare organizations. First, because MTBs require multidisciplinary expertise, smaller practices may need to collaborate with other entities.

Additionally, there may be a lack of access to drugs or clinical trials that limits patients being treated with the recommended regimen. Clinical trials would need to be available locally, as well as expanded use of anticancer therapies.

There are also challenges with the use of next-generation sequencing, the researchers said. While this technique allows for the identification of novel potential targets for patients with cancer to improve outcomes, using this approach widely is difficult because of the variations in genetic makeup.

“One of the hurdles is that every cancer patient appears to be carrying different molecular and genomic patterns despite having the same cancer type,” said Shumei Kato, MD, associate professor of medicine at UC San Diego School of Medicine and first author of the study.

“This can be challenging since we are customizing therapy based on the unique genomic pattern patients have, and thus it is difficult to predict the response. In addition, this approach requires multidisciplinary expertise as well as access to drugs or clinical trials not always available in smaller practices.”

The method proved promising for advanced cancer types. Future studies should involve larger sample sizes to further explore the ability for precision medicine approaches to improve cancer outcomes.

“Our MTB successfully facilitated the interpretation of multiple testing modalities. Further clinical investigation is warranted in order to validate these findings, as well as to determine if there are matching score thresholds that determine the utility of precision therapies,” the team concluded.