Stability assessment of serum tumour markers: Calcitonin, chromogranin A, thyroglobulin and anti-thyroglobulin antibodies.

BACKGROUND: There is limited published data on the stability of calcitonin, chromogranin A, thyroglobulin and anti-thyroglobulin antibodies in serum. The aim of this study was to determine stability at three temperature conditions over 7 days, reflecting current laboratory practices. METHODS: Surplus serum was stored at room temperature, refrigerated and in the freezer; for 1, 3, 5 and 7 days. Samples were analysed in batch and analyte concentrations compared to that of a baseline sample. Measurement Uncertainty of the assay was used to determine the Maximal Permissible Difference and thus the stability of the analyte. RESULTS: Calcitonin was found to be stable for at least 7 days in the freezer but only 24 h refrigerated. Chromogranin A was stable for 3 days when refrigerated and only 24 h at room temperature. Thyroglobulin and anti-thyroglobulin antibodies were stable under all conditions for 7 days. CONCLUSION: This study has enabled the laboratory to increase the add-on time limit of Chromogranin A to 3 days, and up to 60 min for calcitonin and inform optimal storage and transportation conditions for referring specimens.

Reduction mammaplasty: a review of managed care medical policy coverage criteria.

BACKGROUND: Insurance companies evaluate the medical necessity for breast reduction surgery based on internal company medical policies, but the correlation of insurance company criteria to the scientifically established indications for reduction mammaplasty has never been studied. The authors obtained 90 insurance company medical policies for reduction mammaplasty to determine whether the criteria on which coverage determinations are made are consistent with published data regarding the indications for this procedure. METHODS: The authors reviewed the medical literature on reduction mammaplasty and identified what conclusions can reasonably be drawn from this literature on the common insurance criteria used to determine medical necessity for reduction mammaplasty. Conclusions based on the medical literature regarding volume of reduction, symptom presentation, conservative therapy, obesity, presence of bra strap grooving and intertrigo, and age at time of reduction were formulated, and these conclusions were compared with the criteria of 90 different health insurance reduction mammaplasty medical policies. RESULTS: The authors were unable to identify any medical policies that could be supported in entirety by the medical literature and many that are completely unfounded based on the medical literature. CONCLUSIONS: Insurance company medical policy requirements with respect to reduction mammaplasty are, in many cases, arbitrary and without scientific basis. Requirements for a specific volume of reduction, a minimum age, a maximum body weight, and a trial of conservative therapy are required by the majority of managed care medical policies, even though scientific support for any of these requirements is not evident in the medical literature.