Why "Sharks Get Cancer, Mole Rats Don't" | Cancer | Loyola Medicine
Friday, May 6, 2016

Why "Sharks Get Cancer, Mole Rats Don't"

New Book by Loyola Doctor Explains How Animals Provide Clues to Cancer Immunity

James Welsh, MD

MAYWOOD, IL –  A provocative new book by Loyola Medicine radiation oncologist James S. Welsh, MD, “Sharks Get Cancer, Mole Rats Don’t: How Animals Could Hold the Key to Unlocking Cancer Immunity in Humans,” explores how animals can help us understand how the immune system can be used to fight cancer.

Dr. Welsh is a professor in the Department of Radiation Oncology of Loyola University Chicago Stritch School of Medicine.

After publication, the book initially was named to Amazon’s list of Hot New Releases in Oncology and Medical Research and reached No. 1 on Barnes & Noble’s lists of new books in Immune System Physiology and Immunology.

“Dr. Welsh explores the scientific history of cancer like never before,” said Norman Wallis, PhD, executive director of the American College of Radiation Oncology. “With examples ranging from galaxies to dinosaurs, creepy mammals to disgusting sea creatures, and even particle physics, he weaves a story as good as any novel. And it comes together in a way that suggests a future cure for cancer.”
 
Dr. Welsh explores fascinating examples of how, in both animals and humans, the immune system in some cases effectively kills tumor cells, while in other cases cancer cells escape detection. He also explains how, contrary to popular belief, it’s possible to catch cancer -- as in the case of Tasmanian devils (marsupials in Australia the size of small dogs).

Tasmanian devils are on the verge of extinction due to a virulent form of contagious cancer. Similarly, clams on the Atlantic seaboard are vanishing due to a contagious leukemia transmitted in sea water. Dogs can contract a contagious cancer as well, but usually overcome it spontaneously. Thereafter, the dogs become impervious to this type of cancer, providing an intriguing clue about the role of the immune system in cancer. 

Animals offer many tantalizing clues about the nature of cancer in humans. Contrary to myth, sharks do get cancer. But naked and blind mole rats generally are not susceptible to the disease. In humans, an uncommon form of dwarfism called Laron syndrome confers near total cancer immunity. In another unusual phenomenon, a man died from ovarian cancer after receiving a kidney transplant from a woman who had the disease. In an even odder case, a tapeworm developed “cancer,” which spread throughout the patient’s body. And in perhaps the book’s most extraordinary case, Dr. Welsh describes the seemingly miraculous cure of one of his patients, named Daniel, who had advanced metastatic melanoma. (Dr. Welsh first wrote about the case in a 2014 Discover magazine article.)

The highly aggressive cancer had spread to Daniel’s liver and bones, and he appeared to have only a few months to live. Daniel suffered excruciating pain from a tumor in his femur (thigh bone). Dr. Welsh offered Daniel local radiation to shrink the tumor, relieve the pain and reduce the risk of a fracture. This palliative treatment was intended only to relieve symptoms, not cure the disease. But three months later, a CT scan found no trace of cancer anywhere. Daniel benefitted from a rare phenomenon called the abscopal effect, in which localized treatment not only shrinks the targeted tumor but distant tumors as well. It appears the local radiation somehow stimulated Daniel’s immune system to attack cancer throughout his body.

“The abscopal phenomenon represents an extreme example of the immune system’s ability to recognize and occasionally overpower even highly advanced cancer,” Dr. Welsh writes.

Earlier attempts to fight cancer with immunotherapy were disappointing. These treatments strengthened the immune system, but also boosted the strength and number of previously unrecognized or underappreciated immunological guardian cells that actually protect the tumor.

However, newer approaches to immunotherapy are showing promise. “Years of skepticism about cancer immunotherapy are finally fading...” Dr. Welsh concludes. “The revolution is on!”

“Sharks Get Cancer, Mole Rats Don’t” is published by Prometheus Books and distributed by Penguin Random House. 

About Loyola Medicine and Trinity Health

Loyola Medicine, a member of Trinity Health, is a quaternary care system based in the western suburbs of Chicago that includes Loyola University Medical Center (LUMC), Gottlieb Memorial Hospital, MacNeal Hospital and convenient locations offering primary and specialty care services from 1,877 physicians throughout Cook, Will and DuPage counties. LUMC is a 547-licensed-bed hospital in Maywood that includes the William G. and Mary A. Ryan Center for Heart & Vascular Medicine, the Cardinal Bernardin Cancer Center, a Level 1 trauma center, Illinois's largest burn center, a certified comprehensive stroke center and a children’s hospital. Having delivered compassionate care for over 50 years, Loyola also trains the next generation of caregivers through its teaching affiliation with Loyola University Chicago’s Stritch School of Medicine and Marcella Niehoff School of Nursing. Gottlieb is a 247-licensed-bed community hospital in Melrose Park with 150 physician offices, an adult day care program, the Gottlieb Center for Fitness, the Loyola Center for Metabolic Surgery and Bariatric Care and the Loyola Cancer Care & Research at the Marjorie G. Weinberg Cancer Center at Melrose Park. MacNeal Hospital is a 374-bed teaching hospital in Berwyn with advanced inpatient and outpatient medical, surgical and psychiatric services, advanced diagnostics and treatments. MacNeal has a 12-bed acute rehabilitation unit, a 25-bed inpatient skilled nursing facility, and a 68-bed behavioral health program and community clinics. MacNeal has provided quality, patient-centered care to the near west suburbs since 1919.

Trinity Health is one of the largest multi-institutional Catholic healthcare systems in the nation, serving diverse communities that include more than 30 million people across 22 states. Trinity Health includes 94 hospitals, as well as 109 continuing care locations that include PACE programs, senior living facilities and home care and hospice services. Its continuing care programs provide nearly 2.5 million visits annually. Based in Livonia, Mich., and with annual operating revenues of $18.3 billion and assets of $26.2 billion, the organization returns $1.1 billion to its communities annually in the form of charity care and other community benefit programs. Trinity employs about 133,000 colleagues, including 7,800 employed physicians and clinicians. Committed to those who are poor and underserved in its communities, Trinity is known for its focus on the country's aging population. As a single, unified ministry, the organization is the innovator of Senior Emergency Departments, the largest not-for-profit provider of home health care services—ranked by number of visits—in the nation, as well as the nation’s leading provider of PACE (Program of All Inclusive Care for the Elderly) based on the number of available programs.