Here's an interesting observation. Chile ranks first in the world for deaths from testicular cancer, according to the World Health Organization (WHO) and Chile’s Ministry of Health (see: Highest death rates for testicular cancer found in Chile). Read on, if you are interested, in the following excerpt from the article:
In 2009, 121 Chilean men died from the disease and 63 of those were 15 to 30 years old, the age group most at risk from the disease. In the U.K., however, where the population is three and a half times the size of Chile, there were only 70 deaths from testicular cancer in 2008, according to the Cancer Research U.K.’s figures. “Testicular cancer figures are low in Chile in relation to the other types of cancers found here, but yes, the figures are high in comparison with the rest of the world,” [said a cancer specialist ].....Testicular cancer has a 95 percent cure rate if caught and treated in time. Such treatments have been available in Chile for over two decades. Cancer experts in Chile recognize that the country has an unusually high rate of testicular cancer, but no one is sure why. “Less than 5 percent of cases can be explained by exclusively genetic or hereditary causes,” [according to a Chilean urologist] “Neighboring countries with the same ‘culture’ have much lower reported mortality rates from the disease than in Chile,” [according to a cancer expert]. [Another cancer expert offered]...a different theory altogether. “This is only a theory and I have no evidence to support this but there’s a lot of natural contamination of water in Chile, by various metals especially arsenic, and perhaps this could have something to do with the high numbers of cases,” he said. “Really, though, no one knows for sure.”
Heavy metal exposure as a possible etiology seems to be a stretch for me. It occurred to me, however, that an infectious etiology might be possible. There was not much current work on this idea but I did find one abstract that draws an epidemiological parallel between testicular cancer and Hodgkin's disease among young males (see: (see: Viral etiology of testicular tumors). Here is an excerpt from the abstract from this older article:
Testicular carcinoma and Hodgkin's disease are among the most frequent malignancies afflicting young men in the 15 to 39-year age group. These malignancies share other epidemiological characteristics as well, including multiple histological tumor types, higher rates of occurrence in white, urbanized populations and upper social classes, relative infrequency among black populations, low but definite familial occurrence and an early geographically acquired lifetime risk irrespective of later migration. Both diseases are increasing in this country. This epidemiological similarity suggests exposure to an infectious agent early in life. The Epstein-Barr virus is known to be oncogenic and neonatal exposure with early infection is believed to be associated with Burkitt's lymphoma in African children. High titers of antibodies to the Epstein-Barr virus capsid antigen also have been reported in a series of studies comparing patients with Hodgkin's disease and controls. Because testicular cancer is epidemiologically similar to Hodgkin's disease and, therefore, might be expected to manifest similar Epstein-Barr virus findings, we performed a viral screen (Epstein-Barr virus, cytomegalovirus, and hepatitis A and B viruses) on blood samples from 56 consecutive patients with clinical stage I germ cell tumors of the testis who had received no active therapy after orchiectomy. Our results show a high incidence (80 per cent) of previous exposure to Epstein-Barr virus and support the hypothesis of a possible infectious origin for testicular carcinoma.
The problem with this theory is that it doesn't explain the lower incidence for testicular cancer in culturally similar neighboring countries where the males would presumably be exposed to similar viruses. I suppose there is also the possibility of some sort of anomaly of cancer data collection or diagnosis in Chile.