The rarity of appendix cancer, accounting for less than 1 percent of tumors that originate in the gastrointestinal tract, and the lack of scientific data for this disease means that current treatment guidelines recommend applying therapies to people with appendix cancer that are intended for those with colon cancer.

To understand why some patients with appendix cancer respond to standard treatment while others do not, University of California San Diego School of Medicine and Moores Cancer Center researchers, in collaboration with Foundation Medicine, performed genetic profiling on 703 appendiceal tumors — the largest such study of this disease to date — to compare mutations present in both cancer types.

The findings, published online August 8 in JCO Precision Oncology, confirm that genetic mutations in appendix cancer are distinct from those found in colon cancer and that mutations in the genes TP53 and GNAS are good predictors of survival among people with appendix cancer.

“For tumors that are rare like appendix cancer, obtaining molecular profiles will help identify potential treatment options since we don’t have the clinical trial data to help guide treatments as we do in common tumors,” said lead author John Paul Shen, MD, a postdoctoral fellow in the lab of co-author Trey Ideker, PhD, UC San Diego School of Medicine professor of medicine… Continue reading.