Causes and risk factors
The major risk factors are phimosis (preputial narrowing), poor local hygiene, smoking, a sexual history of many partners or first sexual intercourse at a very young age, UVA treatments, the presence of warts and chronic inflammatory conditions such as for example balanoposthitis, lichen sclerosus and atrophic (balanitis xerotica obliterante). It is also proven that HPV (human papilloma virus), especially types 16 and 18, is responsible for the transmission of genital warts, sharp warts and squamous cell carcinomas; it is found in 40-50% of PC cases but other cofactors are needed to pass from a stage of simple local viral infection to the presence of cancer and, moreover, the presence of HPV in the PC does not worsen the prognosis. Pre-pubertal circumcision is a protective factor that reduces the risk of PC by 3-5 times.
Which are the symptoms?
In more than 95% of cases the PC is therefore a squamous cell carcinoma, often preceded by premalignant lesions; malignant penile melanomas and basal cell carcinomas are much rarer. Premalignant lesions are in turn subdivided into those less frequently associated with subsequent tumor development (cutaneous wart, obliterating xerotic balanitis, lichen sclerosus and atrophic) and into those most frequently associated with it (penile intraepithelial neoplasia, Queyrat's erythroplasia, Bowen's disease). The clinical presentation of the PC is variable (ulcerated lesion, exophytic, papule), typically painless and with onset, in descending order, on the glans, foreskin, coronal sulcus, shaft. Metastases are preferentially lymph nodes, when they affect the liver, bones, lungs at a distance.
How is it diagnosed?
The diagnosis of PC is primarily based on an accurate physical examination of the external genitalia, aimed at verifying: number, location, size and morphology (papillary, nodular, ulcerative or flat) of the penile lesion (s); relations with adjacent structures; color and margins of the lesion; length of the penis. A biopsy of the lesion is therefore necessary to have histological certainty of the type of the lesion and to be able to continue with the most appropriate treatment. An MRI scan of the erect penis, obtained by local injection of prostaglandin E1, is useful for evaluating the possible invasion of the corpora cavernosa by the tumor. Another important aspect is the palpation of the inguinal lymph nodes, the first site of any metastases. In the absence of palpatory abnormalities, an ultrasound can help to detect any abnormal lymph nodes and can also be used as a guide for a needle aspiration biopsy. If swollen inguinal lymph nodes are found, CT examination, magnetic resonance imaging and PET-FDG are useful tests to investigate the presence of pelvic lymph node metastases and any distant metastases. In metastatic and symptomatic patients, bone scan is indicated.
How is it treated?
The treatment of primary PC is as conservative as possible taking into account the size, location and relationship with the surrounding tissues. Fundamental in surgical treatment is obtaining pathology-free resection margins, in order to avoid recurrence. Therefore, it ranges from minimal surgical resections of the disease (which can also be performed with alternative techniques such as laser therapy, cryotherapy) to ever greater resections, such as glandulectomy, partial penile amputation (if the corpora cavernosa is invaded) and total (if the urethra is invaded). In the case of further invasive disease, therapy includes neoadjuvant chemotherapy and, in responsive patients, subsequent surgery. In advanced and metastatic diseases, the therapy is palliative chemotherapy. Radiotherapy is both a possible alternative for limited lesions (<4 cm) and a further palliative option. Inguinal and / or pelvic lymphadenectomy, unilateral or bilateral, is performed in case of positivity or suspected positivity of the corresponding lymph nodes.