Epidemiolgy:
Kevin
Rare in the U.S., one per one hundred thousand each year or less than 1% of male cancers.1 Circumcision done early in life has been found to protect against penile cancer however if the procedure is done later in life has no effect. This can explain higher incidence in areas of the world where circumcision is not routine. Narrowing of the opening of the prepuce (foreskin) known as phimosis, is common in men that have been diagnosed with cancer of the penis.
Etiology:
Kevin
The following are risk factors for developing penile carcinoma:2
  • Age 60 or older
  • Uncircumcised men
  • HPV or other sexually transmitted diseases
  • Phimosis (a condition where the foreskin of the penis cannot be pulled back over the glans)
  • Poor personal hygiene
  • Use of tobacco products
Signs & Symptoms:
Jenn
Some of the signs and symptoms of penile cancer:3

  • Change in the skin of the penis.
  • Wart-like growth or lesion that may or may not be painful
  • Open sore that won’t heal
  • Reddish rash
  • Small crusty bumps
  • Flat blush brown growths
  • Swelling at the end of the penis
  • Persistent, smelly discharge under the foreskin
  • Swollen lymph nodes in the groin if the cancer has spread
Diagnostic Procedures:
Jenn
Penile lesions usually affect the skin on the surface of the penis, so a doctor often can find cancers and other abnormalities by looking closely at the penis.4

Diagnostic procedures include:
  • Biopsy
  • Fine needle aspiration
  • Computed tomography
  • Magnetic resonance imaging
  • Ultrasound
Histology:
Rachel
  • The most common type of penile cancer is well-differentiated squamous cell carcinoma.5
  • Transitional cell carcinoma, adenocarcinoma, and undifferentiated or mixed carcinomas represent approximately 15%, 5%, and 1%, respectively.
  • Most carcinomas of the penis start within the preputial area, arising in the glans, coronal sulcus, or the prepuce.
Lymph node drainage:
Rachel
  • The lymphatic drainage of the skin of the shaft and the prepuce channels into the superficial inguinal nodes located above the fascia lata.5
  • For the most part, the lymphatic drainage can be considered bilateral. There is a rich network of lymphatics within the penis and at its base.
  • The sentinel nodes are located above and medial to the junction of the epigastric and saphenous veins. These are the primary drainage sites for carcinoma of the penis. It might not be necessary to do a complete nodal dissection if these groups of nodes are not involved.
Metastatic spread:
Brandon
The most common site for metastasis in penile cancer is the inguinal lymph nodes.6 In patients with clinically nonpalpable inguinal nodes, there is a 20% chance of micrometastasis elsewhere throughout the body. Nodal metastasis is reported in roughly 35% of all patients. Patients with palpable inguinal lymph nodes have a 50% incidence of metastasis.
Grading:
Brandon
For the most part if tumors are not specified by a certain grading system, the most common system is cell differentiation..10 With this system cells are determined how (well or poorly) differentiated they are compared to the normal cells in the surrounding area. Grade 1 usually has a much better prognosis than Grade 4:7
  • GX: Grade cannot be assessed (undetermined grade)
  • G1: Well Differentiated (low grade)
  • G2: Moderately Differentiated (intermediate grade)
  • G3: Poorly Differentiated (high grade)
  • G4: Undifferentiated (high grade)
Staging:
Ashley
The staging of penile cancer is as follows:8
AJCC cropped.jpg
Figure 1. Reprinted from Radiation Oncology Management Decisions.1

Radiation side effects:
Ashley
The goal of external beam radiation therapy and brachytherapy is to destroy cancer cells and prevent them from multiplying.9 While irradiating the cancer tissues, there is healthy tissue that is irradiated as well. While radiation personnel pay close attention to the doses to these tissues, side effects can occur. Some of the side effects that men experience with penile cancer include swelling, redness and sensitivity at the radiation site. In some cases, men may experience tender, oozing or peeling skin and/or a burning sensation while urinating. In external beam radiotherapy, the patient may experience any number of symptoms throughout their treatment. However, with brachytherapy, side effects are greatest approximately 1-2 weeks after treatment is completed and improve over a 1-2 month span. Patients may notice the skin of the penis become pigmented or tighter and telangiectasia (blood vessels) may also become visible. More serious side effects include necrosis, narrowing of the urethra and an abnormal opening between the urethra and skin. Patients with radiation to the nodal areas may also experience tiredness, nausea, or diarrhea.
Prognosis:
- The 5 year survival rate for stage I and II penile cancer is 85%10
- The 5 year survival rate for stage III and some stage IV penile cancer is 59%
- If the cancer has spread to distant body parts, the 5 year survival rate is 11%
Treatments:
Surgery: the most common treatment for all stages of penile cancer11
  • Mohs microsurgery
  • Laser surgery
  • Cryosurgery
  • Wide local excision
  • Partial or total penectomy
Radiation therapy
  • Requires customized bolus
  • 2.5-3.5Gy per fraction for a total of 50-55Gy
  • 1.8-2Gy per fraction for a total of 60-65Gy (last 5-10Gy given in reduced portals
Brachytherapy
  • 60-65Gy in 6-7 days
  • Single or double plane 60-70Gy in 5-7 days
Chemotherapy: used to treat advanced stage tumors11
Biotherapy: uses patient’s immune system to fight the cancer
Radiosensitizers: drugs that make tumor cells more sensitive to radiation therapy
TD 5/5:
Lindsey
Tissue dose associated with 5% injury rate within 5 years12
-Skin: Acute and chronic dermatitis 5500cGy
-Rectum: Ulcer, stricture 6000cGy
-Bladder: Contracture 6000cGy
-Testis: Sterilization 100cGy
References:
  1. Washington C, Leaver D. Principles and Practice of Radiation Oncology. 3rd ed. St. Louis, MO. Mosby Elsevier; 2010: 839.M
  2. MedicineNet.com. Penis Cancer. http://www.medicinenet.com/penis_cancer/article.htm . Accessed June 17, 2013
  3. Penile Cancer Symptoms. Available at:
    http://www.mdanderson.org/patient-and-cancer-information/cancer-information/cancer-types/penile-cancer/symptoms/index.html. Accessed on June 13, 2013
    .
  4. How is penile cancer diagnosed. American Cancer Sociey. Available at:
    http://www.cancer.org/cancer/penilecancer/detailedguide/penile-cancer-diagnosis. Accessed June 19, 2013
  5. Chao K, Perez C, Luther B. Radiation Oncology Management Decisions. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2011: 544-545.
  6. Chao K, Perez C, Luther B. Radiation Oncology Management Decisions. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2002: 481
  7. National Cancer Institute. Available at: http://www.cancer.gov/cancertopics/factsheet/detection/tumor-grade. Accessed on June 21,2013.
  8. Chao K, Perez C, Luther B. Radiation Oncology Management Decisions. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2011: 546.
  9. Radiation Therapy for Penile Cancer. American Cancer Society. http://www.cancer.org/cancer/penilecancer/detailedguide/penile-cancer-treating-radiation-therapy. Revised January 17, 2013. Accessed June 17, 2013.
  10. Survival Rate for Penile Cancer. American Cancer Society. http://www.cancer.org/cancer/penilecancer/detailedguide/penile-cancer-survival-rates. Accessed June 17, 2013.
  11. Penile Cancer Treatment. National Cancer Institute. http://www.cancer.gov/cancertopics/pdq/treatment/penile/Patient/page4. Accessed June 17, 2013.
  12. Washington CM, Leaver D. Principles and Practice of Radiation Therapy. 3rd ed. St. Louis, MO: Mosby Elsevier; 2010: 81.



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