ORANGE COUNTY — At least six children in Ladera Ranch have been diagnosed with Ewing sarcoma, prompting a public health review and calls for a federal investigation. Assistant U.S. Attorney Bill Essayli asked the Environmental Protection Agency to investigate the cancer cluster to determine if there is an environmental cause.

Ladera Ranch is a community in Orange County, California, with a population of approximately 26,000. The cases have drawn the attention of local officials and residents, who are seeking answers regarding the potential causes of the rare disease in their neighborhood. Hundreds of residents attended a community meeting to voice concerns about the cancer cases.

Many residents believe the cancer cases are linked to the use of herbicides and pesticides in the community. A temporary ban on the use of toxic chemical products is in place in Ladera Ranch while a local advisory committee reviews landscaping maintenance practices.

Katrina Foley is the vice-chair of the Orange County Board of Supervisors. She urged the state to expedite a review of the cases and provide timely, transparent updates in a letter sent last week. "Ladera Ranch families deserve answers, transparency and urgency from the state," Foley said. "We do not yet know what caused these cancers, but that uncertainty demands a comprehensive review of every credible factor, including possible environmental exposures, along with direct communication and the public release of the findings."

Essayli is an assistant U.S. attorney. He called on EPA Administrator Lee Zeldin to investigate if environmental factors could be driving the cancer cluster. "The Centers for Disease Control and Prevention (CDC) and National Cancer Institute recognize that unusual patterns of cancer and community concerns regarding potential environmental exposures should be evaluated through a systematic, science-based process," Essayli said.

R. Lor Randall is the Chair of the Department of Orthopedic Surgery at the University of California, Davis. He stated it would be premature to state that any particular exposure caused the Ladera Ranch cases. Randall stated the cases are sufficiently unusual and concerning to justify a rigorous public health investigation. Ewing sarcoma is not generally considered an inherited cancer, according to Randall.

Lily Dalton, 23, died from Ewing sarcoma in January after being diagnosed shortly after her college graduation. Residents have reported additional cancer cases in adults and pets in Ladera Ranch. The Orange County Health Care Agency has called for a review of cancer data with the California Cancer Registry, the UC Irvine Cancer Center, and the Orange County Agricultural Commissioner’s Office.

Ewing sarcoma is a rare cancer that primarily affects bone and soft tissue and is largely seen in children and young adults. The American Cancer Society reports there are no known lifestyle-related or environmental causes of Ewing sarcoma. The American Cancer Society states that fewer than 250 children and young adults are diagnosed with Ewing sarcoma in a single year. Approximately 200 children and teens are diagnosed with Ewing sarcoma each year, according to cancer.org.

Dr. Noah Federman is the director of the pediatric sarcoma program at UCLA. Federman served as the primary oncologist for many of the Ewing sarcoma cases in Ladera Ranch. Ewing sarcoma is caused by a genetic rearrangement of cancer cells, most commonly involving two genes coming together on two separate chromosomes, according to Federman.

The disease primarily affects people aged between 10 and 20, often developing during puberty when bones are growing, he said. Symptoms of Ewing sarcoma include pain, swelling, and tenderness near the affected area, which can be mistaken for sports injuries. Telltale red flags for Ewing sarcoma include severe pain that persists and occurs at night, accompanied by a mass at the site, according to Federman. Other symptoms of Ewing sarcoma include bone breaks without injury and paralysis in arms and legs if the tumor compresses the spinal cord, according to Federman. The cancer can metastasize to the lungs, other bones, bone marrow, lymph nodes, and rarely to the liver and brain, he said. Only 20 to 30% of patients with metastatic Ewing sarcoma will be long-term survivors, according to Federman. The city of Irvine banned the use of toxic synthetic pesticides on all public property about a decade ago.

The concentration of Ewing sarcoma cases in Ladera Ranch has triggered multiple levels of government response, from local health agencies to federal requests. The Orange County Health Care Agency is coordinating with state and academic institutions to review cancer data, while a resident-led push has resulted in a temporary ban on toxic chemical products pending a review of landscaping practices.