Mono-Hodgkin's Link Seen

(AP)  Young adults who get mononucleosis, the "kissing disease," have more than double the risk of developing a rare type of cancer, a Danish study found.

Doctors have long suspected a link between mononucleosis and Hodgkin's disease, a highly treatable cancer of the lymph system. But the role played by the common virus that causes mono was uncertain. The virus, Epstein-Barr, is found in about one-third of Hodgkin's tumors.

In a study of over 63,000 young adults suspected of having mono, the researchers found that those who got mono had a higher-than-average chance of getting Hodgkin's, and the risk lasted for two decades. There was no increased risk for those who did not have mono.

"I think it removes the last shade of doubt that the virus actually has something to do with causing Hodgkin's disease," said Dr. Richard Ambinder of Johns Hopkins School of Medicine, who was not involved in the research. "The flip side to that is that everyone's got the virus, so it can't possibly be the whole story."

The Danish researchers stressed that Hodgkin's disease, also known as Hodgkin's lymphoma, is uncommon. About one in 1,000 of young adults with mono will get the cancer, they said.

"Only in rare circumstances will this lead to the development of Hodgkin's lymphoma. So there's no reason for any panic," said Dr. Mads Melbye, one of the researchers at Statens Serum Institut, the Danish equivalent of the U.S. Centers for Disease Control and Prevention.

The study is reported in Thursday's New England Journal of Medicine.

Hodgkin's accounts for less than 1 percent of cancer in the United States, and is most common in those ages 15 to 34 and those over 55. According to the American Cancer Society, about 7,600 new cases will be diagnosed this year.

Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, said parents and patients should not be overly concerned about the study's findings.

"This doesn't change our practice or our patterns. It enhances our knowledge," Lichtenfeld said.

Ambinder said the research raises the possibility of preventing Hodgkin's in those who have had mono or diagnosing it earlier.

"There's fertile ground for more research," he said.

Most everyone is infected at some point with the Epstein-Barr virus, which is spread through saliva, and the virus remains dormant for life. In children, there are usually few or no symptoms from the infection. But when exposure first occurs in adolescence or later, it can cause mono. Symptoms include fever, sore throat, swollen glands and fatigue.

The research included 38,555 Danish and Swedish patients diagnosed with mono and 24,614 Danish patients who were tested for mono but did not have it. Cancer registries were checked to determine how many later developed Hodgkin's disease, which typically occurred four years after mono.

Sixteen of 29 Hodgkin's tumors tested from the mono group contained the virus.

The findings suggest that there are other causes for Hodgkin's besides the Epstein-Barr virus, Melbye said. "It's a cause, not THE cause," he said.

Melbye said the study's results should apply to the United States, which has rather similar rates of mono and Hodgkin's.

By Stephanie Nano