Basal Cell Carcinoma Does NOT Count as Neoplastic Disease in the PSI Score
Basal cell carcinoma should be excluded from the Pneumonia Severity Index (PSI) score's neoplastic disease criterion because it has a metastatic rate of less than 0.1% and does not represent systemic cancer burden. 1
Rationale for Exclusion
Negligible Metastatic Potential
- Basal cell carcinoma exhibits an extremely low metastatic rate of less than 0.1%, indicating negligible systemic cancer risk and supporting its exclusion from prognostic scoring systems 1, 2
- Although BCC is locally invasive and can cause substantial local tissue destruction and disfigurement, it rarely metastasizes to distant sites 3, 2
- The disease behaves characteristically indolent with minimal impact on systemic health 3
Standard Practice in Cancer Classification
- Non-melanoma skin cancers, particularly basal cell carcinoma, are routinely excluded from cancer registries and prognostic scoring tools because they do not significantly affect morbidity or mortality 1
- Including BCC in the PSI score would inappropriately inflate risk scores for patients whose systemic cancer burden remains unchanged, potentially leading to overtreatment 1
- Treating locally invasive BCC as a systemic malignancy conflates local tissue destruction with true metastatic disease, which are fundamentally different clinical problems 1
Distinction from Other Malignancies
- Although basal cell carcinoma accounts for approximately 75% of all skin cancers, it is deliberately separated from other malignancies in clinical practice due to its unique, low-risk behavior 2
- Non-melanoma skin cancers are rarely fatal, with less than 0.1% of deaths caused by these types of cancer 2
The Rare Exception
In the exceedingly rare circumstance of metastatic basal cell carcinoma (occurring in <0.1% of cases), the disease should be considered a systemic malignancy and counted in the PSI score. 1