bubble_chart Overview

Carcinoma of the penis is not uncommon and accounts for a significant proportion of male tumors. The incidence of penile carcinoma varies greatly due to factors such as country, region, ethnicity, religion, and hygiene habits. Generally, the incidence is lower in European and American countries, while it is higher in Asian, African, and Latin American countries. However, the incidence is very low among Jewish populations and in Muslim countries that practice Islam.

bubble_chart Etiology

Carcinoma of the penis is closely related to phimosis and redundant prepuce, with long-term irritation from smegma being the primary disease cause. Clinically, about half of the cases have phimosis. Jewish males undergo circumcision shortly after birth and almost never develop carcinoma of the penis. Islamic males are circumcised during childhood, and their incidence of penile carcinoma is significantly lower than that of other ethnic groups. However, circumcision in adulthood does not reduce the incidence of penile carcinoma. The relationship between trauma, sexually transmitted diseases, and the onset of penile carcinoma remains inconclusive.

bubble_chart Clinical Manifestations

Carcinoma of the penis often originates in the glans or the inner lining of the foreskin. Due to its growth beneath the foreskin, early detection is difficult. The lesion appears as a papillary or flat protrusion, with raised edges around the ulcer, secreting foul-smelling fluid, and may eventually penetrate the foreskin to expose the tumor. Carcinoma of the penis rarely occurs in the shaft of the penis or the urethral meatus, possibly due to less exposure to smegma, and is commonly found near the coronal sulcus, where smegma irritation is most frequent. Carcinoma of the penis seldom invades the corpus spongiosum or the bladder. Generally, if the tumor exceeds 15 cm, metastasis is common. Flat tumors are more prone to lymph node metastasis than papillary ones. The tumor may invade the corpus cavernosum upon penetrating the tunica albuginea, though this is uncommon and usually occurs after lymph node metastasis. Over 90% of penile carcinomas are squamous cell carcinomas. Most tumors are low-grade, and survival rates are not strongly correlated with cellular grade. However, undifferentiated carcinomas have a poor prognosis.

bubble_chart Diagnosis

The typical case of carcinoma of penis is not difficult to diagnose through clinical examination. However, due to the presence of phimosis or delayed medical attention, the diagnosis is often delayed. If an ulcer or mass is present on the glans or foreskin and does not respond to 10–14 days of antibiotic treatment, carcinoma of penis should be suspected. When the diagnosis of a mass or ulcer on the glans cannot be confirmed, a biopsy should be performed.

Carcinoma of penis may metastasize to the inguinal lymph nodes, presenting as palpable superficial lymphadenopathy. Due to the high incidence of lymphadenitis, confirmation requires biopsy or lymphangiography. Metastatic lymph nodes are often hard, fixed, and non-tender. If the lymph nodes do not shrink after the primary lesion has been excised or after antibiotic treatment, and if the lymphadenopathy is located medial to the junction of the great saphenous vein and femoral vein, it is highly likely to be a metastatic site of carcinoma of penis and should be taken seriously.

bubble_chart Treatment Measures

(1) Surgical Treatment Surgical excision of the lesion is the primary treatment method. If the lesion is confined to the foreskin, circumcision can be performed, with statistics showing a recurrence rate of around 50%. If the tumor invades the glans penis, partial penectomy may also be performed. Generally, resection 2 cm away from the tumor is sufficient, and frozen section examination of the resection margin should confirm the absence of tumor during the procedure. Since the spread of carcinoma of the penis is often due to embolic metastasis rather than the lymphatic infiltration into surrounding tissues typical of most tumors, local recurrence is rare in the vast majority of cases after a 2 cm margin resection. If there is no inguinal lymph node metastasis, the 5-year survival rate post-surgery is 70–80%. For larger tumors where the residual pendulous portion of the penis is too short to allow standing urination, total penectomy with perineal urethrostomy is performed. Recent reports indicate that Nd:YAG laser therapy for carcinoma of the penis yields favorable results.

The indications for inguinal lymph node dissection have been debated for years. In cases of carcinoma of the penis where no enlarged inguinal lymph nodes are clinically palpable, the incidence of micrometastasis in lymph nodes is 2–5%. However, some reports suggest a false-negative rate as high as 38%, with metastasis occurring in 20–50% of cases. Routine inguinal lymph node dissection is not currently recommended, as over half of patients may not have metastatic lesions, and the procedure can lead to complications such as skin necrosis, infection, pulmonary embolism, and late-stage (third-stage) lower limb lymphedema, which are relatively common and cause unnecessary suffering. If clinically suspicious metastatic lesions (i.e., enlarged lymph nodes) are present, a biopsy may be performed, with serial sectioning if necessary during seasonal epidemics. Lymph node dissection is performed if metastasis is confirmed. Routine bilateral lymph node dissection during seasonal epidemics is generally not recommended. The lymph node located medially at the junction of the great saphenous vein and femoral vein is termed the "sentinel node." If metastasis is confirmed, deep and superficial inguinal lymph node dissection should be performed, including resection of the iliac and inguinal lymph nodes.

(2) Radiotherapy Radiotherapy is controversial. Some advocate radiotherapy alone for carcinoma of the penis, but its application is limited due to complications such as urethral stricture, urinary fistula, penile necrosis, and edema caused by high-dose irradiation. Infection and necrosis in carcinoma of the penis can also reduce the efficacy of radiotherapy. Early-stage carcinoma of the penis may be treated with X-ray irradiation in combination with bleomycin, with good results.

(3) Drug Therapy Currently, anticancer drugs such as fluorouracil and cyclophosphamide are used for carcinoma of the penis, but their efficacy is not significant. Some have reported good results with bleomycin, with a total dose of up to 300 mg. Chemotherapy can also be combined with surgery and radiotherapy.

bubble_chart Prognosis

The prognosis of carcinoma of the penis is related to tumor stage, timing of treatment, treatment methods, patient age, and tumor malignancy. Approximately three-quarters of patients with stage I carcinoma of the penis survive for 5 years after surgery, while the 5-year survival rate drops to half for those clinically diagnosed at stage I. For patients with metastasis who undergo inguinal lymph node dissection, the 5-year survival rate is only about one-third.