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Marcos Roberto Tavares

Publications and source records attributed to Marcos Roberto Tavares.

6 recordsLinked to original sources
PubMed2006

Clinical suspicion and parathyroid carcinoma management.

CONTEXT AND OBJECTIVE: Adequate management of parathyroid carcinoma apparently relates to the surgeons ability to identify it at the first operation. The objective of this paper was to evaluate the role of clinical suspicion in the management of parathyroid carcinoma. DESIGN AND SETTING: Retrospective analysis of parathyroid carcinoma patients treated in Department of Head and Neck Surgery, Faculdade de Medicina da Universidade de São Paulo. METHODS: Cross-sectional study of 143 patients who underwent surgery from 1995 to 2000, due to hyperparathyroidism. These cases were reviewed to ascertain whether preoperative and intraoperative suspicion of parathyroid carcinoma were helpful during the operation, and which factors demonstrated the suspicion of cancer best. RESULTS: Among 66 patients with primary hyperparathyroidism there were four cases of parathyroid carcinoma (6.1%), and one case was found in secondary hyperparathyroidism (1.3%). Palpable nodules were found in five patients with primary hyperparathyroidism, four of them with parathyroid carcinoma. Preoperative levels of calcium in primary hyperparathyroidism with cancer patients varied from 12.0 mg/dl to 18.2 mg/dl. Two patients had gross macroscopic spread of the tumor to adjacent structures. Except for one patient, with extensive disease, tumors were resected en bloc. In secondary hyperparathyroidism, parathyroid carcinoma was found in a fifth mediastinal gland. One atypical adenoma was observed. CONCLUSIONS: High levels of calcium, palpable tumors and adherence to close structures are more common in parathyroid carcinoma. These clinical signs may be helpful for decision-making during parathyroid surgery.

Adenoma↗
PubMed2006

Immunohistochemistry quantification by a digital computer-assisted method compared to semiquantitative analysis.

PURPOSE: To compare immunostaining quantification obtained by a digital computer-assisted method with the well-established semiquantitative analysis. METHODS: Cytoplasmic staining of galectin-3 was obtained by standard immunohistochemical reactions in 25 cases of well-differentiated thyroid carcinoma. The expression index that associates the conventional area fraction of labeled cells with the immunostaining intensity score based on visual qualitative observation was used as the semiquantitative analysis. A digital computer-assisted method is described based on the use of an image processing program (ImageLab). Three parameters were obtained: (1) percentage of labeled cells; (2) digital immunostaining intensity, and (3) digital expression index. The proposed method allows numerical analysis of the immunostaining intensity. RESULTS: There was a strong correlation between the immunostaining intensity obtained by the two methods (Pearson correlation coefficient, r = 0.71, P = 0.0001). The same was observed between expression indexes (Pearson correlation coefficient, r = 0.66, P = 0.0001). CONCLUSION: Results obtained with our proposed digital computer-assisted method for immunoexpression analysis were concordant with the semiquantitative analysis. In addition, digital values can also resolve disagreement among different observers about the quality of staining intensity because the digital method does not classify the results into groups, but rather provides a numerical value for each individual case; thus, it increases the diagnostic and, more importantly, the prognostic sensitivity of the immunohistochemical analysis.

Analysis of Variance↗
PubMed2005

Angiogenesis as an indicator of metastatic potential in papillary thyroid carcinoma.

UNLABELLED: Angiogenesis is new blood vessel formation, a process that can lead to tumor development. Microvessel count has been correlated to metastasis in some neoplasias. PURPOSE: To determine if measurement of microvessel density is useful in predicting metastasis to the cervical lymph node and prognosis in patients with papillary thyroid carcinoma. METHODS: A retrospective analysis was performed in 30 patients that had undergone total thyroidectomy. They were divided in 2 groups of 15 patients--with and without metastatic disease. Immunohistochemistry was used to detect expression of CD34 in archival paraffin-embedded papillary thyroid tumors, and microvessel density was calculated based on it. Association between microvessel density and the presence of metastasis, according to histological subtype, disease recurrence, and AMES prognostic index groups was determined through statistical analysis. RESULTS: The median microvessel density for the patient group without metastasis (200.0 microvessels/mm2) was apparently, but not significantly, less than that observed among metastatic disease patients (254.4 microvessels/mm2) (P=.20). When papillary carcinoma subtypes were analyzed, this difference became significant (P=02). The follicular variant exhibited a greater microvessel density than the other subtypes, independent of metastasis presence. There was an apparent, but not significant, tendency for a larger median microvessel density in the group of patients that presented recurrence (294.4 microvessels/mm2 vs 249.6 microvessels/mm2, P=.11). There was no relationship between risk level and microvessel density: in the low- and high-risk groups, the median MVD was 304.0 microvessels/mm2 and 229.6 microvessels/mm2, respectively (P=.27). CONCLUSIONS: The results suggest that angiogenesis is more intense among metastatic tumors in the classic and the tall cell variants, indicating that microvessel count can be an indicator of the potential for metastasis in these subtypes of papillary thyroid carcinoma. Patients that developed recurrent disease had a tendency to exhibit higher angiogenesis; however, there was no association between microvessel density and the AMES prognostic index.

Adolescent↗
PubMed2004

Fat food habitual intake and risk of oral cancer.

This case-control study evaluated fat food habitual intake in the context of the Brazilian diet as a risk factor for oral cancer. A food frequency questionnaire was applied to 70 patients with oral carcinoma and an equal number of controls treated in the same hospital for acute non-neoplastic conditions. Participants were paired for age, gender and smoking status, and matched by frequency for the use of dental prostheses and length of smoking history. Conditional logistic regression for multivariate analysis indicated as risk factors the habitual intake of foods rich in animal and saturated fat: pork meat, soup, cheese, bacon and fried food. The multivariate model also indicated the protective effect of non-cooked butter or margarine, probably the most effective vehicle for vitamin A ingestion in the Brazilian diet. These findings suggest that there is a non-negligible scope for the prevention of oral cancer through the improvement of diet.

Adult↗