Stages Predictor
Predicts the expected number of Mohs stages using a weighted algorithm based on tumor type, anatomical location, size, subtype, and high-risk features. Displays probability distributions for surgical planning.
Privacy: All calculations are performed locally in your browser. No patient data is transmitted, stored, or shared.
This platform is not a HIPAA Business Associate. Do not enter identifiable patient information.
Algorithm Methodology
Stage predictions are based on a weighted algorithm using published data from Leibovitch et al. (2005) and van Loo et al. (2014). The model calculates a base expected stage count from a probability table indexed by tumor type, NCCN zone (H/M/L), and size category (<5mm, 5-10mm, 10-20mm, >20mm).
Risk Modifiers (additive increments to expected stages):
- Infiltrative/morpheaform BCC subtype: +0.35
- Recurrent tumor: +0.30
- Perineural involvement: +0.40
- Ill-defined clinical borders: +0.20
- Prior radiation therapy: +0.25
Probability distributions are recalculated by shifting mass from single-stage outcomes toward multi-stage outcomes proportional to the total risk increment. Confidence levels reflect the number of active risk factors.
References
- Mulvaney PM, Schmults CD. Prognostic factors and staging in cutaneous squamous cell carcinoma. Facial Plast Surg Clin North Am. 2020;28(1):9-23.
- Hoorens I, Batjen D, Herms F, et al. Mohs micrographic surgery for basal cell carcinoma: an analysis of factors determining the number of Mohs stages. J Eur Acad Dermatol Venereol. 2021;35(1):184-190.
- National Comprehensive Cancer Network (NCCN). Basal Cell and Squamous Cell Skin Cancer. NCCN Clinical Practice Guidelines in Oncology. Version 1.2026.
For clinical decision support only. Stage predictions are statistical estimates and vary by individual case. This tool does not replace clinical judgment or intraoperative decision-making.