TABLE 2.

Prognostic factors associated with disease-specific survival (multivariate analysis)

Variable	HR (95% CI)	p value
Age at diagnosis (year)
< 45	Reference
45–59	0.46 (0.07–3.26)	0.439
60–69	0.70 (0.10–4.87)	0.721
70–79	1.39 (0.15–13.07)	0.772
80+	0 (0–1.77e170)	0.967
Race
White	Reference
Black	0.90 (0.16–4.85)	0.906
Other	0.72 (0.06–8.95)	0.797
Tumor size (cm)
< 3	Reference
≥3	5.60 (1.50–21.20)	0.012
Lymph nodes
Negative	Reference
Positive	19.86 (2.01–196.71)	0.307
Extent of disease
Local disease	Reference
Regional disease	1.54 (0.32–7.38)	0.588
Metastatic disease	104.45 (9.89–1103)	0.0001
Surgery
No	Reference
Yes	0.72 (0.17–3.01)	0.962
Extent of resection
Parathyroidectomy	Reference
En bloc resection	0.72 (0.17–3.01)	0.648
Unknown	2.04 (0.21–19.74)	0.539
Radiation
No	Reference
Yes	1.59 (0.44–5.85)	0.848
Grade
Well-differentiated	Reference
Moderately differentiated	6.23 (0.21–183.28)	0.289
Poorly differentiated	4.40 (0.22–89.79)	0.335
Undifferentiated	10.53 (0.34–325.84)	0.179