Effects of short-term metformin therapy associated with levothyroxine dose decrement on TSH and thyroid hormone levels in patients with thyroid cancer.

AIM: Suppressive therapy with levothyroxine is the main step in treatment of differentiated thyroid cancer (DTC). However, subclinical hyperthyroidism is associated with deleterious effects on cardiovascular and skeletal systems. Metformin may have a suppressive effect on TSH level. METHODS: We performed a single blind randomized controlled trial on the effect of short term Metformin therapy on 50 non-diabetic patients with DTC (mean age of 39.68 ±8.7 years) under suppressive therapy with levothyroxine. Metformin (500 mg) or placebo was added to the drug regimen of the patients and levothyroxine dose decreased by 33%. TSH and thyroid hormone values were measured at the beginning of the study and 3 months after treatment. RESULTS: Forty-six patients had papillary and 4 had follicular carcinoma. The mean dose of levothyroxine was 2.2±0.48 µg/kg. The mean TSH level at the beginning of the study was 0.05±.04 mIU/L. The mean age, weight and baseline TSH level was not significantly different between metformin and placebo groups (P>0.2). In the metformin group, the mean (±SD) TSH level was significantly increased from 0.03±0.04 to 3.1±5.7 mIU/L after 3 months of intervention (P=0.01) and the mean thyroid hormone levels were significantly decreased (P<0.001). In the placebo group, the mean TSH level increased from 0.04±0.04 to 3.1±4.7 mIU/L after 3 months (P=0.003). Delta TSH was 3.0±5.6 mIU/L and 3.1±4.7 mIU/L in metformin and placebo groups, respectively (P=0.9). CONCLUSION: Adding 500 mg of metformin to drug regimen was not useful to compensate for 33% of levothyroxine dose reduction in patients with DTC.

Factors affecting sentinel lymph node detection failure in breast cancer patients using intradermal injection of the tracer

ObjetivoLa biopsia selectiva del ganglio centinela es el método estándar para la estadificación axilar del cáncer de mama. En algunas pacientes el ganglio centinela no es identificado durante la cirugía y tiene que realizarse una linfadenectomía axilar estándar. En este estudio hemos evaluado los factores predictores del fallo en la localización del ganglio centinela utilizando la administración intradérmica del radiotrazador combinada con la inyección de colorante azul de metileno.Material y métodosSe evaluaron retrospectivamente 202 pacientes consecutivas con cáncer de mama, clínicamente estadios I o II. Se analizan y comparan diferentes variables entre las pacientes cuyo ganglio centinela se localizó durante la cirugía y aquellas que no fue posible la detección del ganglio centinela.ResultadosEl ganglio centinela fue identificado en la linfogammagrafía previa en 180 pacientes (89%). El análisis uni y multivariable mostró que la no visualización del ganglio centinela en la linfogammagrafía, la experiencia del cirujano y la existencia de metástasis en los ganglios axilares se asocian con fallo de localización del ganglio centinela durante la cirugíaConclusionesEste estudio muestra la importancia de la linfogammagrafía previa a la cirugía para predecir aquellos pacientes con posible fallo en la localización quirúrgica del ganglio centinela. Recomendamos la necesidad de una fase de aprendizaje de la técnica antes de su aplicación clínica rutinaria(AU)

ObjectiveThe standard method for axillary lymph node staging in early breast cancer is sentinel lymph node biopsy. In some patients the sentinel lymph node can not be localized during surgery and these patients have to undergo standard axillary lymph node dissection. In this study we have evaluated the predictors of sentinel lymph node localization failure using 99mTc-antimony sulfide colloid and intradermal injection combined with blue dye technique.Material and methods202 consecutive patients with early stage breast cancer (clinically stage I or II) were retrospectively evaluated. Patients whose sentinel lymph node was localized during surgery were compared to those with localization failure considering several variables.ResultsSentinel lymph node was successfully located on the pre-operative lymphoscintigraphy images in 180 patients (89%). Both univariate and multivariate analyses showed that only sentinel lymph node non-visualization by pre-operative lymphoscintigraphy, experience of the surgeon, and axillary lymph node involvement are associated with sentinel node localization failure during surgery.ConclusionsThis study shows the importance of pre-operative lymphoscintigraphy in order to identify the group of patients with possible localization failure during surgery and warning the surgeon beforehand. We also recommend that all surgeons pass the learning curve of sentinel lymph node biopsy before routinely performing this procedure(AU)

Factors affecting sentinel lymph node detection failure in breast cancer patients using intradermal injection of the tracer.

OBJECTIVE: The standard method for axillary lymph node staging in early breast cancer is sentinel lymph node biopsy. In some patients the sentinel lymph node can not be localized during surgery and these patients have to undergo standard axillary lymph node dissection. In this study we have evaluated the predictors of sentinel lymph node localization failure using (99m)Tc-antimony sulfide colloid and intradermal injection combined with blue dye technique. MATERIAL AND METHODS: 202 consecutive patients with early stage breast cancer (clinically stage I or II) were retrospectively evaluated. Patients whose sentinel lymph node was localized during surgery were compared to those with localization failure considering several variables. RESULTS: Sentinel lymph node was successfully located on the pre-operative lymphoscintigraphy images in 180 patients (89%). Both univariate and multivariate analyses showed that only sentinel lymph node non-visualization by pre-operative lymphoscintigraphy, experience of the surgeon, and axillary lymph node involvement are associated with sentinel node localization failure during surgery. CONCLUSIONS: This study shows the importance of pre-operative lymphoscintigraphy in order to identify the group of patients with possible localization failure during surgery and warning the surgeon beforehand. We also recommend that all surgeons pass the learning curve of sentinel lymph node biopsy before routinely performing this procedure.