Epidemiological trends in penile cancer and the evolving role of dynamic sentinel lymph node biopsy

Penile cancer (PeCa) is a rare but aggressive malignancy with growing global incidence. The most influential prognostic factor in PeCa is the presence of nodal metastasis. Current imaging modalities lack the diagnostic accuracy to reliably detect micro-metastasis in PeCa. Since 2015, Dynamic Sentinel Lymph Node Biopsy (DSLNBx) emerged as a means of accurately detecting nodal metastases in PeCa. The impact of DSLNBx on overall and cancer-specific survival years remains to be established in the Irish population.

Population based data was obtained from The National Cancer Registry of Ireland (NCRI) on all patients diagnosed with PeCa between 1994 and 2021. Log-rank Mantel-Cox analysis was applied to assess survival benefit associated with DSLNBx.

A total of 866 patients were diagnosed with PeCa in Ireland between 1994 and 2021 with population standardized incidence incrementing from 1.68 to 2.80 cases/100,000 males/year during this period. The most common histological subtype was squamous cell carcinoma (92.8%) followed by melanoma (2.7%), basal cell carcinoma (0.7%). Surgical excision constituted mainstay treatment (86.2%). DSLNBx was performed in 8% of cases of which 13% had node positive disease. Those who underwent DSLNBx were found to have a statistically significant increase in overall survival rate, χ² (1) = 4.067, P = 0.044. Cancer specific survival rate correlated positively in those who underwent DSLNBx also, but this did not reach statistical significance.

PeCa has growing incidence in Ireland. DSLNBx offers a means of accurately assessing presence of nodal metastasis whilst incurring minimal morbidity which has been associated with improved overall survival on univariate analysis.