Trends in the relative frequency of histologically diagnosed epithelial dysplasia and intra-oral carcinoma in Northern Ireland, 1975-1989.
Trends in the incidence of histologically diagnosed dysplastic lesions of the intra-oral mucosa have been investigated for the period 1975-89 in a well defined population of 1.5 million. These have been contrasted and compared with trends in the incidence of intra-oral carcinoma. Cases were ascertained from the records of all the histopathology laboratories that serve the Northern Ireland population. Over the 15-year period, there were 135 cases of histologically diagnosed epithelial dysplasia. In contrast to the significant increase in the incidence of intra-oral carcinoma, there was no significant change in the annual age standardised incidence of dysplastic lesions over the period. The ratio of malignant to dysplastic diagnoses rose from 2.5:1 to 5.4:1. Only 24 of the dysplastic lesions were known to have subsequently progressed to malignant carcinoma, representing 4.5% of all invasive tumours diagnosed during 1975-89. The results highlight a number of unresolved issues regarding the natural history of intra-oral carcinoma.
Gregg
T A
TA
School of Dentistry, Queen's University of Belfast, Royal Victoria Hospital, Belfast, Northern Ireland.
Cowan
C G
CG
Kee
F
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000473:pathology; D009062:Mouth Neoplasms / Q000453:epidemiology*; D009660:Northern Ireland / Q000453:epidemiology; D011230:Precancerous Conditions / Q000453:epidemiology*; D012044:Regression Analysis