16:04 11 September 2012
Young men who recreationally smoke marijuana are at twice the risk of being diagnosed with testicular cancer, a major American study has confirmed.
Findings published in the journal Cancer stated that the link looked specific to a type of tumour known as nonseminoma.
Victoria Cortessis of the University of Southern California led the study. She was quoted by the Telegraph as saying: "I myself feel like we need to take this seriously now.
"This is the third study consistently demonstrating a greater than doubling of risk of this particularly undesirable subtype of testicular cancer among young men with marijuana use."
Cortessis cited that the rates of testicular cancer have been rising sharply over the past century.
However, testicular cancer is often viewed as one of the least threatening types. Of the one in 270 who contract it, the American Cancer Society state the risk of dying from the disease is just one in 5,000 because of the effective treatment available to combat it.
Cortessis and her colleagues collected data from 163 young men who had been diagnosed with testicular cancer as well as nearly 300 in a comparison group who didn't have the disease. A long ranging study, both groups had been interviewed about their general health and drug use between 1987 and 1994.
They discovered that of the men who had the cancer, 81% of those had admitted to smoking the drug at some point while those in the comparison group were at 70%.
However, the study failed to chart whether those who used the drug a lot were at a higher risk.
But Cortessis is not dismayed by this, saying that plenty of prior evidence helps to establish a strong case for a link. She said: "It is hard to imagine a scenario whereby it is due to chance and I can't think of a systematic bias that would cause this. I will feel very confident that this is cause and effect once we have worked out the biology."