Predictors of distant metastasis in acinic cell carcinoma of the parotid gland

Table 1 Demographics and clinical information, n (%)

Characteristic	Patients with lung metastases (n = 6)	Patients without lung metastases (n = 49)	P value
Age at diagnosis (yr)	57.8	40.2	0.064
Gender
Male	5 (83.3)	21 (42.9)
Female	1 (16.7)	28 (57.1)
Parotidectomy type			0.00013
Superficial	1 (16.7)	39 (79.5)
Total	5 (83.3)	10 (20.4)
Neck dissection	3 (50.0)	7 (14.3)	0.08
Positive margins	1 (16.7)	6 (12.2)	0.77
Gross nerve invasion	6 (100)	0	< 0.0001
Greatest dimension	5.20 cm	2.58 cm	< 0.0001
Initial overall stage
I	0	21 (42.8)
II	0	19 (38.7)
III	0	06 (12.2)
IV	6 (100)	2 (4.1)
Unknown
Initial T-stage
T1	0	24 (48.9)
T2	0	18 (36.7)
T3	0	6 (12.2)
T4	6 (100)	1 (2.0)
Tx	0	0
Initial nodal status
N0	5 (83.3)	47 (95.9)
N1	0	1 (2.0)
N2	1 (16.7)	1 (2.0)
N3	0	0
Nx	0	0
High-grade	3 (50)	1 (2.0)	0.019
Adjuvant XRT	5 (83.3)	14 (28.6)	< 0.001

XRT: X radiotherapy.

Table 2 Characteristics of patients with lung metastases

Patient characteristics	Grade	T-classification	Facial nerve invasion	Recurrence sites
63 yr Male	High	T4a	Yes	Local, distant (lungs)
77 yr Female	Low	T4a	Yes	Distant (lungs)
44 yr Male	High	T4a	Yes	Distant (lungs)
52 yr Male	High	T4a	Yes	Distant (lungs)
71 yr Male	Low	T4a	Yes	Regional, distant (lungs)
40 yr Male	Low	T4a	Yes	Local, regional, distant (lungs)