Innovative use of a known medication provides a hopeful alternative to conventional chemotherapy for individuals diagnosed with appendix cancer.
Researchers at the University of California San Diego School of Medicine have discovered that an FDA-approved drug typically used for breast cancer may be an effective treatment for a particular type of appendix cancer.
In the results of a clinical trial published in the October 16, 2024, online issue of the Journal of Clinical Oncology, the oral drug palbociclib demonstrated its ability to stabilize tumor growth and lower blood tumor marker levels in patients suffering from peritoneal mucinous carcinomatosis (PMC), a cancer that starts in the appendix and frequently does not respond to standard chemotherapy methods.
“The fact that a medication designed for breast cancer can effectively treat a specific kind of appendix cancer, where treatment options are limited, represents a major breakthrough in tackling this illness,” stated co-senior author Andrew Lowy, MD, a professor in the Department of Surgery and chief of the Division of Surgical Oncology at UC San Diego School of Medicine, as well as the clinical director for cancer surgery at Moores Cancer Center at UC San Diego Health. “This discovery brings forth the first targeted therapy for this uncommon cancer.”
Appendix cancer is very rare, making up less than 1% of all gastrointestinal cancers. The American Cancer Society estimates that there are fewer than 2,000 new cases diagnosed each year in the United States.
The study included 16 individuals diagnosed with PMC, most of whom had undergone previous treatments unsuccessfully. Researchers examined the genetic changes present in these tumors and found that tumors with mutations in the GNAS gene responded positively to the drug. In over 80% of these patients, there was a decrease in blood markers linked to cancer activity.
Lab results also indicated that the drug halted or slowed the growth of cancer cells, providing a more manageable alternative to chemotherapy, which often leads to severe side effects.
“This drug can be used right away, eliminating the need for waiting on a new medication to be developed or for FDA clearance,” noted co-senior author Shumei Kato, MD, an associate professor at UC San Diego School of Medicine and a medical oncologist at UC San Diego Health.
Kato, who is also affiliated with the UC San Diego Moores Cancer Center, emphasized that this study highlights the innovative use of existing cancer therapies.
“The results pave the way for a promising new phase in the treatment of appendix cancer, as well as possibly other rare cancers with similar genetic profiles.”
Future research will focus on exploring how palbociclib can be combined with traditional chemotherapy and newer targeted therapies for improved efficacy.
“This groundbreaking study reinforces our unique standing as the only National Cancer Institute (NCI)-designated Comprehensive Center in the area and our dedication to finding and providing state-of-the-art treatment options,” expressed Diane Simeone, MD, the director of Moores Cancer Center at UC San Diego Health. “As an academic medical institution, our clinical researchers are at the forefront of trials that are revealing promising new therapies and bringing hope to patients who have had limited options in the past.”
Co-authors of this study include: Jonathan Weitz, Daisuke Nishizaki, Joy Liau, Jay Patel, Isabella Ng, Siming Sun, Dana Ramms, Jingjing Zou, Brian Wishart, Jordan Rull, Joel Baumgartner, Kaitlyn Kelly, Rebekah White, Jula Veerapong, Mojgan Hosseini, Hitendra Patel, Gregory Botta, Silvio Gutkind, and Herve Tiriac, all associated with UC San Diego.
Financial backing for the research was partially provided through grants from the Levine Family Chancellor’s Endowed Chair in Surgical Oncology, National Organization for Rare Disorders, and the Appendix Cancer Pseudomyxoma Peritonei Research Foundation (R21CA273974, 1F32CA265052-01), along with generous contributions from the estate of Elisabeth and Ad Creemers, the Euske Family Foundation, the Gastrointestinal Cancer Research Fund, and the Peritoneal Metastasis Research Fund. Confocal imaging and histology core supported by the UC San Diego Health Specialized Cancer Support Center (P30 2P30CA023100).
