Mold Toxin May Be Behind Testicular Cancer
Cancer researcher proposes theory of cause of disease that strikes mostly young men
WEDNESDAY, Feb. 13, 2002 (HealthDayNews) -- The treatment of testicular cancer is something of a modern success story, with the vast majority of cases now curable.
But the cure doesn't come without a cost -- infertility, for one. And the search for a definitive cause has yielded no good suspects.
Enter a Wake Forest University cancer researcher, who has come up with an interesting -- albeit highly preliminary -- hypothesis that might explain why the disease strikes the way it does.
Gary Schwartz, an associate professor of cancer biology and public health sciences, proposes that testicular cancer, the most common form of cancer among young men, might be caused by exposure to ochratoxin A, a carcinogen found in mold that grows on grains and coffee beans. It's also found in animals, particularly pigs, that eat moldy grain.
"Really, it's an idea," says Schwartz. "It's a guess. It's not proven."
Schwartz's theory is outlined in the February issue of Cancer Causes and Controls, and it reads much like a detective tale.
Too often, searching for the cause of a particular disease is close to impossible. Testicular cancer, however, has several unique characteristics that make the search less daunting.
For one thing, the disease is most prevalent among white males in the 15-to-34 age range, which suggests that exposure to the carcinogen occurs very early in life, even as early as the womb.
Testicular cancer rates are also higher in Northern Europe than in Central or Southern Europe, and are the highest in Denmark, which has 7.8 cases per 100,000 per year. It's also more common among people of higher socioeconomic levels, the same group most likely to be breast-fed.
Oddly, the incidence of this type of cancer went way down among Danish and Norwegian men born during World War II, and increased again after the end of the war.
That provided an important clue, Schwartz says.
"The tip-off is that whatever causes it is related to some kind of goods or provisions because these countries were occupied and Sweden was blockaded," explains Schwartz. "Whatever it is is very likely to be related to some commodity. The question is 'What?'"
The plot thickens when you consider that pigs are apt to develop certain kidney problems when they eat rye that often contains ochratoxin A.
The mold is also known to cause kidney cancer in rats and mice. In fetuses, the testicles develop from the kidneys.
"It's not implausible that something that causes cancer in a kidney could also cause cancer in an organ that developed out of the kidney," says Schwartz. "It's definitely a guess, but it's not an outlandish guess."
As it turns out, Danes have some of the highest rates of pork consumption in the world. They also eat a great deal of rye, the cereal grain most often contaminated by ochratoxin A. Weather conditions during the harvest season promote growth of the mold, Schwartz explains.
Schwartz's theory goes like this: A woman eats products contaminated with ochratoxin A while she's pregnant, or her child consumes them as a youngster. This damages the testicular DNA, and puberty triggers a malignancy.
If his hypothesis holds true, Schwartz says women could take drugs such as aspirin and the vitamins A, C and E, which reduce the DNA damage of ochratoxin A.
"It's a great start," says Marianne Berwick, an associate attending epidemiologist at Memorial Sloan-Kettering Cancer Center in New York City. "He's done his best to support it with different types of evidence, but at this point all he really has is an interesting hypothesis."
Schwartz's hypothesis now needs to undergo rigorous scientific testing but, as Berwick points out, many scientific discoveries start out just this way.