ret/PTC expression may be associated with local invasion of thyroid papillary carcinoma.
OBJECTIVE
The exact role of ret/PTC in the development of papillary carcinoma remains unclear. Expression of the ret/PTC oncogene was examined immunohistochemically to address its role in the progression of thyroid carcinomas.


METHODS
Paraffin-embedded samples from 34 clinically evident thyroid papillary carcinomas and 19 occult papillary carcinomas were analyzed using an antibody raised against the ret tyrosine kinase domain.


RESULTS
Expression of ret/PTC was demonstrated in 6/19 (32%) occult carcinomas. The frequency of expression of ret/PTC in clinically evident carcinomas in 16/34 (47%) was significantly higher than in normal tissues (0%) and follicular adenomas (1/14, 7%, P < 0.01).ret/PTC expression was observed more frequently in the peripheral areas of clinically evident carcinomas (P < 0.01). Although there was no correlation of ret/PTC expression with tumor size, lymph node metastasis, or distant metastasis, the incidence of ret/PTC expression in tumors with extrathyroidal invasion (13/19, 68%) was significantly higher than those without extrathyroidal invasion (3/15, 20%, P < 0.01). Local invasion was found in none of the occult carcinomas. The frequency of expression in occult carcinomas was significantly lower than in clinically evident carcinomas with extrathyroidal invasion (P < 0.05).


CONCLUSIONS
The ret/PTC oncogene may be involved in the local invasion of thyroid papillary carcinomas.
Miki
H
H
Second Department of Surgery, School of Medicine, University of Tokushima, Japan. miki@clin.med.tokushima-u.ac.jp
Kitaichi
M
M
Masuda
E
E
Komaki
K
K
Yamamoto
Y
Y
Monden
Y
Y
D000236:Adenoma / Q000378:metabolism / Q000473:pathology; D018276:Carcinoma, Medullary / Q000378:metabolism / Q000473:pathology / Q000556:secondary; D002291:Carcinoma, Papillary / Q000378:metabolism* / Q000473:pathology* / Q000556:secondary; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D009361:Neoplasm Invasiveness; D056918:Nuclear Receptor Coactivators; D015513:Oncogene Proteins / Q000096:biosynthesis*; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology*; D014157:Transcription Factors
C111382:NCOA4 protein, human; D056918:Nuclear Receptor Coactivators; D015513:Oncogene Proteins; D014157:Transcription Factors