Cyclooxygenase-2 expression in medullary thyroid carcinoma.

BACKGROUND: Recent studies have demonstrated that cyclooxygenase-2 (COX-2) expression is associated with the carcinogenesis of numerous neoplasms. The aim of this study was to evaluate the role of COX-2 in medullary thyroid carcinoma (MTC). METHODS: Tissue specimens of thyroid neoplasms were obtained from 22 patients with MTC and 15 control subjects with nonmalignant thyroid specimens. RESULTS: This immunohistochemical study confirms the presence of COX-2 in a significant number of MTCs. A large area of staining was noted in only 2 patients in the control group (13%) compared with 18 (82%) in the medullary carcinoma group. On a scale of 0 to 3, the average area of positive staining measured 2.35 in the study group and 0.9 in the control group (p < .0001). The average intensity of staining on a scale of 0 to 5 (deep brown) was 2.15 and 0.8 mm, respectively (p < .001). CONCLUSION: COX-2 is expressed significantly in MTC including a larger area of staining and greater intensity than in nonmalignant thyroid tissue. These findings may have important treatment implications for the use of COX-2 inhibitors in patients with MTC.

Value of minimal residual disease in patients with early cancer of the tongue.

PURPOSE: The clinical course of patients with squamous cell carcinoma (SCC) of the tongue is often unpredictable. Some patients have a fair course with good response to treatment, whereas others have aggressive locoregional disease despite diagnosis at an early stage. The purpose of the present study was to determine if histochemical staining for cytokeratins of the negative neck nodes obtained in prophylactic neck dissection could predict treatment failure in patients with SCC of the tongue. MATERIALS AND METHODS: Between 1990 and 2000, 18 patients with early squamous cell carcinoma of the tongue (T1,T2N0M0) underwent partial glossectomy with neck dissection at the Rabin Medical Center in Israel. All had clear resection margins and no evidence of neck metastasis and were expected to do well. Nevertheless, 6 patients had an aggressive course and died of disease shortly after presentation because of local or regional failure. In an attempt to predict failure of treatment and patients' outcome, paraffin-embedded blocks from the pathologically negative lymph nodes were subjected to immunohistochemical staining for cytokeratin using polyclonal antibodies. The antigen-antibody complex was identified by using the biotinylated secondary antibody and followed by the streptavidin-peroxidase detection method. RESULTS: None of the 142 sections from pathologically negative lymph nodes stained positive for keratin. On multivariate analysis, a statistically significant relationship was found between disease-free survival, early recurrence (P =.03), and metastasis to the neck (P =.008). CONCLUSIONS: Keratin staining failed to yield evidence of micrometastasis. Further studies with more samples are needed to confirm these findings.