Urethral Cancer

Posted on 13/10/2017 by admin — No Comments ↓

What is Urethral Cancer?

Urethral cancer (UC) is the rarest type of urological cancer, with less than 2000 known cases. Urethra is a tube-shaped organ that connects the bladder with the urethral opening for the removal of urine. Males and females have a different anatomy of the urethra, and it plays a role when deciding on treatment. UC is a carcinoma- it develops from cells of the urethral lining^[1].

urethral cancer

Causes

The exact causes of UC are not known. There are risk factors that have been associated with UC:

Chronic irritation of urethra
Infection- sexually transmitted diseases, HPV
Arsenic ingestion has been linked to UC
Exposure to radiation (for example-previous cancer treatment)^[2]

Symptoms

Initially there might be no symptoms. Mostly the symptoms are associated with narrowing of the urethra, like trouble emptying the bladder or overflow incontinence. More specific symptoms are perineal pain and haematuria. Other symptoms include:

Diminished stream of urine
Voiding sensation
Frequent urination, also during night
Itching
Purulent or watery, smelling discharge
Pain in the pubic area
Haematospermia
Swelling of the urethral opening
Pain during intercourse^[2]

Diagnosis

Physical examination

During physical examination, some signs can be found that suggest UC:

Fistula from urethra to the skin
Regional lymph nodes enlarged and painful
Bloody or mucosal discharge from urethra
Fistula to the vagina
Urethral diverticula
Abscess or tissue necrosis
Lesions of the penis or vagina
Palpable mass ^[4,1]

Laboratory studies

There are no blood analyses that can prove the diagnosis of UC. Usually they are used for differentiating UC from an infection. Increased alkaline phosphatase levels can suggest skeletal metastases. Urine analysis and culture should be performed in order to exclude infection^[4].

Histology

To confirm the diagnosis, usually transurethral biopsy is performed. During this procedure a sample of tissue is taken to further evaluate it^[4]. There are 4 histological types of urethral cancer:

Urothelial carcinoma- with malignant cells that resemble the epithelium of bladder (also see transitional cell carcinoma)
Squamous cell carcinoma– composed of sheets of large tumor cells in various shapes

Squamous cell carcinoma

Adenocarcinoma- composed of simple columnar epithelium (also see bile duct adenocarcinoma)
Clear cell adenocarcinoma- cuboidal, different sized cells (also read about clear cell renal cancer) ^[7]

male urethral cancer

Imaging studies

MRI is the method of choice in diagnosing UC.MRI shows the extent of disease and can help in planning the treatment. MRI can also help the assessment of therapy.

CT and X-ray of the chest, pelvis and the abdomen is also helpful in assessing metastatic distribution of UC^[4].

Other tests

Flexible cystoscopy is a minimally invasive procedure during which a flexible tube with camera is inserted into urethra to visually evaluate it. During cystoscopy a papillary mass, erythematous areas or ulceration of the mucosa can be seen, and it can suggest cancer ^[4].

Staging

Staging of any cancer is important part of planning the treatment. UC is staged based on the TNM classification- tumor, node, and metastasis.

T-primary tumor

Tx- primary tumor cannot be assessed
T0- no evidence of primary tumor
Ta- non-invasive carcinoma
Tis-carcinoma in situ
T1- tumor invades subepithelial connective tissue
T2-tumor invades corpus spongeosum, prostate (in men) or periurethral muscle (in women)
T3-tumor invades corpus cavernosum, tissue beyond prostatic capsule (in men) or anterior vagina, neck of the bladder (in women)
T4- tumor invades other organs- the bladder

N- lymph nodes

Nx- lymph nodes cannot be assessed
N0- no metastasis in regional lymph nodes
N1- metastases in single lymph node, not bigger than 2cm
N2- metastases in single lymph node, bigger than 2cm, but smaller than 5cml
N3- metastases in lymph node that are larger than 5 cm

M-metastases

Mx- metastases cannot be assessed
M0- no metastases
M1- distant metastases present (most commonly liver and lungs)^[2]

Treatment

Therapy for urethral cancer varies with the stage and location of the tumor. Since this tumor is so rare, there is no statistically certain choice for treatment^[4,5].

Radiation therapy

Radiation therapy is used as primary treatment option, as well as combination together with chemotherapy and/or surgery. In small, early stage lesions radiation can be very successful and the treatment will not require surgery. Radiation also has high rate of success in woman, because surgery has significantly higher risk of morbidity ^[4,5].

Chemotherapy

Chemotherapy is sometimes used alone, but more often together with radiation therapy. The data about the effects of chemotherapy are limited. Similarly to squamous cell cancer, chemotherapy regime of methotrexate, vinblastine doxorubicin and cisplatin is used in combination with radiation for locally advanced disease^[4,5].

Surgical treatment

Surgery is the method of choice for both males and females. The extent of surgical treatment depends of the stage and location of the cancer. There have been 4 methods described for surgical treatment:

Conservative therapy and local excision
- Transurethral excision of low grade tumor
- Endoscopic treatment with transurethral electro-resection or laser therapy
- Segmental resection with reconstruction- a part of urethra is removed, and the healthy part is mobilized to create new urethral opening. Not usable for woman.
Partial penectomy
- Excision of the lesion with around 2cm margins
- Can be used for distal, infiltrative tumors in men
Radical penectomy
- Removal of the penis, urethra and penile root
En block resection
- For tumors higher than T2 stage in the prostatic part of urethra
- Procedure includes removal of the affected urethra as well as local lymphnodes
- In women portions of perineal tissue also are removed
- In women most cases require removal of the vagina ^[5]

Prognosis

Urethral cancer is very rare and the treatment usually is very aggressive. Despite aggressive treatment with radiation, chemotherapy and surgery, recurrence rate is more than 50%. Due to the aggressive treatment, many patients experience complications:

Stricture (narrowing) of urethra
Inflammation of bladder and urethra caused by radiation
Bowel irritation
Fibrosis
Bleeding
Formation of fistula
Secondary cancer^[6]

Survival rate

Both sexes

Age- more than 65 years and African American race
Size, tumor location
Stage, grade, involvement or lymph nodes and metastasis
Type of treatment
Presence of concomitant bladder cancer

For men:

Invasion of the cancer in prostate
Invasion in lymph vessels and nerves
Tumors in the proximal urethra have a worse prognosis.

The 5 year survival rate depends on the stage of the tumor. For lower stage tumors it is around 83%, while in later stage tumors the survival rate is around 45% ^[6].

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References

General patient information: http://www.webmd.com/cancer/tc/urethral-cancer-treatment-patient-information-nci-pdq-general-information-about-urethral-cancer
Causes and staging: http://www.urologyhealth.org/urologic-conditions/urethral-cancer/causes
Symptoms: http://www.medicinenet.com/urethral_cancer/page2.htm
Diagnosis: http://emedicine.medscape.com/article/451496-workup#c4
Treatment: http://uroweb.org/wp-content/uploads/08-Primary-Urethral-Carcinoma_LR1.pdf
Prognosis and relevant anatomy: https://www.cancer.gov/types/urethral/hp/urethral-treatment-pdq
Histology and prognostic factors: http://www.pathologyoutlines.com/topic/urethracarcinoma.html

Urethral Cancer

What is Urethral Cancer?

Causes

Symptoms