Classification of parathyroid cancer
Annals of Surgical Oncology, 04/13/2012
Schulte KM et al. – This study confirms the validity of both classification systems for disease outcome in patients with parathyroid cancer.Methods
- This study contains 82 formerly unreported patients with parathyroid cancer.
- Death due to disease was the primary end point, and recurrence and disease-free survival were the secondary end points.
- Data acquisition used a questionnaire of predefined criteria.
- Low risk was defined by capsular and soft tissue invasion alone; high risk was defined by vascular or organ invasion, and/or lymph node or distant metastasis.
- A differentiated classification system further classified high-risk cancer into vascular invasion alone (class II), lymph node metastasis or organ invasion (class III), and distant metastasis (class IV).
- Statistical analyses included risk analysis, Kaplan-Meier analysis, and receiver–operating characteristic (ROC) analysis.
- Follow-up ranged 2–347 months (mean 76 months).
- Mortality was exclusive to the high- risk group, which also predicted a significant risk of recurrence (risk ratio 9.6; 95% confidence interval 2.4–38.4; P < 0.0001), with significantly lower 5-year disease-free survival (χ2 = 8.7; P < 0.005 for n = 45).
- The differentiated classification also provided a good prognostic model with an area under the ROC curve of 0.83 in ROC analysis, with significant impairment of survival between classes (98.6%, 79.2%, 71.4%, 40.0%, P < 0.05 between each class).