Regarding the epidemiology of testis cancer, which of the following is FALSE?
Answer A
The trend of testis cancer is one of increasing incidence, the reason not being clear but dietary and environmental factors no doubt will be contributing to this. Rising incidence is seen with geographical increasing latitudes with Scotland having the highest incidence in the UK. Although you may not be expected to know all the intricacies of the epidemiology of individual European nations, it is relevant to know that the trend is on the increase.
With regards to germ cell neoplasia in situ (GCNIS) of the testis, which of the following is TRUE?
Answer D
The incidence across the general population is 0.8%. The incidence of GCNIS in the contralateral testis in patient with a testicular cancer is 5%. Progression to carcinoma is 50% at 5 years and 70% at 7 years. Testicular microlithiasis is not an independent risk factor and as per EAU guidelines and is only relevant in patients with other risk factors (such as cryptorchidism or atrophy) and exists in 2%–6% of the general population. Once GCNIS is diagnosed in the remaining testis, radiotherapy is advised which will affect spermatogonia and render patients subfertile but will not affect Leydig cell function.
Which of the following is FALSE with regard to tumour markers in testis cancer?
AFP has a half-life of 5–7 days. β hCG has a half-life of 24–36 hours. These need to be borne in mind when checking post-operative or post-treatment levels. Lactate dehydrogenase (LDH) is a ubiquitous enzyme which is non-specific for tumour type. Overall 50% of patients will have raised markers at diagnosis. 5%–10% of pure seminomas will have a raised β hCG (produced by syncytiotrophoblast elements). 90% of non-seminomatous GCTs may have elevated markers. 50%–70% will have a raised AFP (produced by yolk sac elements) and 40% will have a raised β hCG. β hCG is raised in 100% of choriocarcinoma’s and 40%–60% of embryonal carcinoma.
Which of the following does NOT cause serum HCG to rise?
Answer C
All except testicular lymphoma can cause a rise in HCG to some degree.
With regards to the genetics of testis cancer, which of the following is TRUE?
The risk is higher if a sibling is affected meaning that the gene locus is likely to be on the X chromosome. Familial studies have suggested a LOD (Logarithm of Odds) in the region of 2 (i.e., suggestive but not definitive of a familial inheritance pattern).
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