Penile cancer is rare – 1 in 100 000 in USA/Europe.
More common in South America, SE Asia and parts of Africa.
Incidence increases with age – from 50 – 60s onwards.
More common in regions with high rates HPV. Vaccination expected to reduce risk.
Risk factors
- Circumcision in childhood reduces risk
- Phimosis increases risk > 10 x
- Chronic penile inflammation (balanoposthitis, BXO)
- Sporalene / ultraviolet A phototherapy (for psoriasis)
- Smoking
- HPV infection
- Rural areas, low socioeconomic status and unmarried status
- Multiple sexual partners and early age of first intercourse (presumably related to HPV)
Neonatal circumcision definite reduces the incidence of penile cancer, but adult circumcision does not appear to reduce risk.
Pre-malignant lesions like CIS are also associated with progression to penile cancer.
Pathology
95 % of penile cancers are squamous cell carcinoma.
Other tumours include melanomas, lymphoma, Kaposi sarcoma, BCC or metastases.
There are multiple subtypes of SCC:
| Good prognosis | Intermediate prognosis | Poor prognosis |
|
Verrucous Papillary Warty
|
Usual type
Mixed Pleomorphic warty |
Basaloid
Sarcomatoid |
Pathological grading is important and helps determine TNM staging.
Grading is graded 1 – 3 (or sarcomatoid) based on cytological atypia, keratinisation, intercellular bridges, mitotic activity and tumour margins.
2022 WHO classification divides to HPV-associated and HPV-independent.
Pathological factors portending poorer prognosis:
- Perineural invasion
- Lymphovascular invasion
- Depth of invasion
- Grade
These factors all increase the risk of lymph node metastases, which is the single most important factor affecting survival and development of metastases.
Staging
| Tx | Tumour can’t be assessed |
| T0 | No evidence primary tumour |
| Tis | Carcinoma in situ |
| Ta | Non invasive verrucous carcinoma |
| T1a | Invades subepithelial tissue – no LVI, not poorly differentiated |
| T1b | Invades subepithelial tissue – LVI or poorly differentiated |
| T2 | Invades corpus spongiosum (+/- urethra) |
| T3 | Invades corpus cavernosum |
| T4 | Invades other adjacent structures |
| cNx | Nodes can’t be assessed |
| cN0 | No palpable or visibly enlarged nodes |
| cN1 | Palpable mobile unilateral inguinal node |
| cN2 | Palpable mobile multiple or bilateral inguinal node |
| cN3 | Fixed inguinal nodal mass or pelvic lymphadenopathy |
| pNx | Nodes can’t be assessed |
| pN0 | No regional lymph nodes |
| pN1 | Metastasis in one or two inguinal lymph nodes |
| pN2 | Metastasis in more than two unilateral, or bilateral inguinal nodes |
| pN3 | Extranodal extension in inguinal nodes, or pelvic lymph node mets |
| Mx | Distant mets can’t be assessed |
| M0 | No distant mets |
| M1 | Distant mets |
| Gx | Grade of differentiation can’t be assessed |
| G1 | Well differentiated |
| G2 | Moderately differentiated |
| G3 | Poorly differentiated |
| G4 | Undifferentiated |