Testicular Cancer – A New Approach To Diagnosis

A study conducted by the researchers at IRC (Institute of Cancer), UK, discovered several genetic parameters that may potentiate the risk of developing testicular cancer in adult men. The researchers claim that a carefully designed genetic test may help in predicting the risk of testicular cancer in adult men with significant precision. The results of the study were published in the peer-reviewed journal Nature Genetics (1).

The lead author of the study and the senior researcher at IRC, Dr. Clare Turnbull claimed that the study has identified numerous variations and alterations in the DNA that are associated with testicular cancer risk in men. The study has also opened new doors to the efficacy of genetic approach for the diagnosis of this disease in men.

Testicular Cancer – A Brief Overview

Testicular cancer is characterized by the malignant transformation of glandular cells within the testicles. The primary male gonads or testicles takes part in the production of testosterone and sperm. Testicles are made of different cellular types and each type may lead to the formation of single or multiple clinical varieties of cancer. However, in majority of the testicular cancer cases, the cancer begins in the germ cells, which take part in the sperm production. This is why, these cancers are referred to as TGCT (testicular germ cell tumors).

Testicular cancer is more prevalent in young males (the peak age of incidence is 15 to 34 years). Fortunately, most cases respond very well to the timely treatment.

Genetic Markers, Risk Loci And Testicular Cancer Risk

Previous genetic studies conducted on a larger scale, have established the co-relation between the testicular cancer and genetic markers. Another study suggested that nearly 50% of all testicular cancer cases are genetically associated i.e. inherited.

This inherited risk has nothing to do with a mutated gene; in fact, it is associated with minor variations in the DNA, also called risk loci.

Dr. Turnbull and his team compiled the data from 3 individual studies for the comparison. The sample consisted of 7,319 DNA samples obtained from men suffering from TGCT and 2308 DNA samples from non-TGCT.

The results indicated that at least 19 new risk DNA changes are linked with an increased risk of developing testicular cancer in men. Altogether, the research team identified at least 44 DNA mutations that may aggravate the risk of testicular cancer in men. The researchers speculated that when a healthy man is evaluated against these genetic markers, it becomes easier to ascertain the risk profile for TGCT by up to 10 times. This can offer better surveillance and an early diagnosis which can be used in better treatment and preventive measures.

Studies to evaluate all 44 markers suggested that men with these genetic changes have a 7% higher risk of developing TGCT. In other words, these men are 14 times more likely to develop testicular cancer when compared to general population.

The team also unraveled the mechanism to a certain extent that leads to DNA variations and disrupt the normal functioning of germ cells, consequently promoting testicular cancer. They discovered the processes that:

• Disrupt the chromosomal stability
• Intervene with the signaling pathways linked to KIT, a cancer gene.

The team speculates that based on the above discoveries, new drugs can be prepared that specifically target the variants of DNA. The lead author thinks there is still more work to be done in this field in order to determine many other genetic markers that can be used for patient surveillance and care.

References

• Litchfield, K., Levy, M., Orlando, G., Loveday, C., Law, P. J., Migliorini, G., ... & Kristiansen, W. (2017). Identification of 19 new risk loci and potential regulatory mechanisms influencing susceptibility to testicular germ cell tumor. Nature Genetics.