What is Testicular Cancer (Seminoma of the Testicle)?

Seminoma of the testicle is a type of testicular cancer. The testes are the male gonads, located within the scrotum. They function in production of sperm (spermatogenesis) and production of sex hormones. The testes actually develop on the posterior surface of the abdominal cavity before migrating to their position in the scrotum, through the inguinal canal, during the 7th month of embryological development. Maldescent of the testes (cryptorchidism) is a risk factor for testicular cancer. It is a common condition of neonatal boys, occurring in up to 30% of premature babies and 5% of term infants. The vast majority will descend spontaneously by the age of 1 year, but no further spontaneous descent will occur beyond this age.

Anatomy of the male reproductive system

Statistics

Seminoma on a whole is uncommon, accounting for approximately 1% of all malignancies in men but has increased incidences in younger men. Testicular cancer is the most common solid organ malignancy in men aged 15-35. Seminoma of the testis accounts for approximately half of germ cells tumours (tumours arising from spermatozoa precursors). It is most common between the ages of 30-40 with sex incidence being obviously male. Geographically, the tumour is found worldwide but with highest incidence in developed countries. Lowest incidence is in African and Asian countries whilst the highest incidence is in Scandinavian countries.

Risk Factors

Cryptorchidism: Almost 10% of testicular tumours are found in patients with cryptorchidism (undescended testes) However, the increased risk of testicular cancer is not confined to the maldescended testis – with up to 25% of these malignancies occurring in the normally descended, contralateral testis. This suggests a common aetiological factor for both testicular cancer and testicular maldescent, rather than maldescent being a cause of testicular cancer.
Other predisposing factors 
Other predisposing factors include, previous testicular cancer, family history of testicular cancer, HIV infection and abnormalities of testicular development (including Klinefelter’s syndrome – where you have two or more X chromosomes).
In utero exposure to oestrogens has been postulated as a predisposing factor in the development of testicular cancer, but remains controversial.
Other potentially predisposing factors include testicular torsion, mumps orchitis, testicular trauma and occupational exposure to various substances including wood dust and chromate dyes. However, definitive evidence of a causative role for these factors is yet to be proven.

Progression

This type of tumour spreads by local destruction of testicular tissue, followed less commonly by lymphatic invasion and spread to regional lymph nodes. However, less than 30% of patients with seminoma will develop metastatic disease. Occasionally, the tumour may spread via the blood to sites such as the lung, liver or bone.

Symptoms

Most patients present with a nodule or painless swelling of the testes which may be discovered incidentally by your sexual partner. Occassionally pain is involved but this is more common for other conditions of the testes such as infection.
Some men may also present initially with symptoms such as a neck mass, bone pain, cough or shortness of breath if the cancer has already spread to other organs. However, the condition normally presents in its early stages.

Clinical Examination

Your doctor will look and feel the scotum and testicles for any evidence of enlargement or nodules. This is usually done standing initially to note the normal position of the testes. The normal testicle is palpated first so it can be compared with the other. Firm, hard or fixed areas may indicate malignancy so will be treated seriously by your doctor and will require further investigation.
You doctor should also palpate surrounding structures, your abdomen and nodes in the neck to determine any evidence of spread of the tumour.

How is it Diagnosed

Most patients with a lump or abnormality in the testicles will undergo a scrotal ultrasound which can determine whether the mass is within the testicle and give some details about its consistency. This is followed by radiography and blood tests looking for tumour markers (enzymes and substances released into the blood by tumour cells).
Radiographic imaging may include chest x-ray, CT scan of the abdomen, and a CT scan of the chest to determine evidence of metastatic disease. Radical inguinal orchiectomy (removal of the testicle for biopsy) is sometimes necessary to obtain the diagnosis.

Prognosis

Seminoma of the testis is associated with a good prognosis, with most tumours following an indolent course. In cases without evidence of lymphatic spread, 5 year survival approaches 100%. Even in the presence of early lymphatic spread, survival is approximately 95%. Thus, as with many malignancies, early diagnosis and intervention are critical to subsequent prognosis in patients with seminoma of the testicle and other testicular malignancies.

Treatment

Treatment involves radical surgical inguinal orchidectomy (removal of the testicle) as part of the diagnosis of testicular seminoma- with tissue diagnosis and histological distinction from other forms of testicular cancer being important in subsequent management.
Seminoma of the testicle is exquisitely radiosensitive and post-surgical radiotherapy is a key part of the treatment approach. Retroperitoneal lymph node dissection is indicated in patients found to have limited metastatic spread in addition to radiotherapeutic treatment.
Chemotherapy is advocated in patients with advanced seminoma. Observation is an experimental approach in the post-operative management of early stage testicular seminoma but should be reserved for highly motivated individuals or as a research tool. It is important to offer semen cryopreservation to all men presenting with testicular carcinoma prior to the commencement of therapy should they wish to preserve fertility. Improvement in symptoms is an important measurement.
Specific monitoring may be by measurement of serum tumour markers (a-fetoprotein, BHCG and LDH) but these are relatively unreliable in the detection of tumour recurrence in patients with seminoma. Appropriate follow-up should include regular self-examination, serial chest x-ray and regular abdominal and thoracic CT. The symptoms that may require attention are visceral pain from metastases and neurogenic pain if nerve tissue is compressed. Coughing and breathlessness from lung involvement may require specific treatment.

References

  1. Andrology Australia. Treatment of Testicular Cancer [online]. 2003 [cited April 17, 2003]. Available from URL: http://www.andrologyaustralia.org/testicular/treatment/radio.htm
  2. Barker JL, Paulino AC. Seminoma. eMedicine [online]. 2002 [cited: November 6, 2002]. Available from URL: http://www.emedicine.com/PED/topic2078.htm
  3. Cotran RS. Kumar V. Collins T. Robbins Pathologic Basis of Disease. Sixth Edition. Philadelphia: WB Saunders Company; 1999.
  4. Davis JW, Schellhammer P. Testicular Seminoma. eMedicine [Online] 2004 [cited: July 8, 2004]. Available from URL: http://www.emedicine.com/med/topic2250.htm
  5. Docimo SG, Silver RI, Cromie W. The Undescended Testicle. Diagnosis and Management. American Family Physician [online]. 2000 [cited: 1 November 2000]. Available from URL: http://www.aafp.org/afp/20001101/2037.html
  6. Dogra VS. Mojibian H. Cryptorchidism. eMedicine [Online] 2004 [cited: July 9 2004] Available from URL: http://www.emedicine.com/radio/topic201.htm.
  7. Dr Timothy Price, Clinical Haematology-Oncology Department, The Queen Elizabeth Hospital.
  8. Frontiers in Bioscience; Seminoma of the Testis. Available from URL: http://www.bioscience.org/atlases/tumpath/mreprod/testis/3/synopsis.htm
  9. Guyton AC, Hall JE. Textbook of Medical Physiology. Tenth Edition. Philadelphia: WB Saunders Company; 2000.
  10. Junilla J, Lassen P. Testicular Masses. American Family Physician [serial online] 1998 [cited: February 15, 1998]; 57(4). Available from URL: http://www.aafp.org/afp/980215ap/junnila.html
  11. Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL. Harrison’s Principles of Internal Medicine. Sixteenth Edition. USA: McGraw-Hill Companies Inc; 2005.
  12. Light D. Testicle, Malignant Tumours. eMedicine [Online] 2004 [cited: July 9, 2004]. Available from URL: http://www.emedicine.com/radio/topic680.htm
  13. McMinn RMH. Last’s Anatomy Regional and Applied. Ninth Edition. London: Churchill Livingstone; 2003.
  14. Steele G, Richie J, Oh W, Michaelson D, Clinical manifestations, diagnosis, and staging of testicular cancer, UpToDate, 2006.
  15. The Australian Institute of Health and Welfare. Cancer in Australia 2001 [online]. 2004 [cited: December 2004]. Available from URL: http://www.aihw.gov.au/publications/can/ca01/ca01.pdf