Table 7. Correlation of the levels of expression of cytoplasmic thymidine phosphorylase (TP-cyt) with clinical features.

	TP-cyt
	No or low expression (%)	High expression (%)	P
Primary tumour site
Oral cavity	6 (55)	5 (45)
Oropharynx	9 (90)	1 (10)	0.009
Hypopharinx	4 (100)	0 (0)
Larynx	1 (17)	5 (83)
Type of disease
Recurrence	5 (36)	9 (64)	0.007
Primary	15 (88)	2 (12)

TP-cyt: cytoplasmic thymidine phosphorylase.