Serum thyroglobulin level measured after thyroxine withdrawal is useful to predict further recurrence in whole body scan-negative papillary thyroid cancer patients after reoperation

Lymph node ratio independently associated with postoperative thyroglobulin levels in papillary thyroid cancer

OBJECTIVES

To investigate the impact of the lymph node ratio (LNR) on postoperative thyroglobulin (Tg) levels in patients with papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

This was a retrospective, cohort study. The association between clinicopathological variables and postoperative unstimulated Tg (uTg) levels, preablative-stimulated Tg (sTg) levels, and postablative unstimulated Tg levels was analysed.

RESULTS

A total of 300 patients with PTC were identified. Multivariate logistic analysis showed that M classification (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.62-3.34), and postoperative thyroid-stimulating hormone levels (OR, 1.01; 95% CI, 1.01-1.02) were independently associated with postoperative uTg levels. One hundred and sixteen patients underwent radioactive iodine (RAI) therapy. Multivariate analysis showed that LNR in the central neck (OR, 1.24; 95% CI, 1.02-1.51), LNR in the lateral neck (OR, 1.73; 95% CI, 1.09-2.77), RAI dose (OR, 1.43; 95% CI, 1.21-1.69), and M classification (OR, 1.79; 95% CI, 1.22-2.61) were independently associated with preablative sTg levels. Tumour size (OR, 1.01; 95% CI, 1.00-1.01), LNR in the central neck (OR, 1.28; 95% CI, 1.08-1.51), LNR in the lateral neck (OR, 1.66; 95% CI, 1.10-2.49), RAI dose (OR, 1.54; 95% CI, 1.34-1.79), and M classification (OR, 1.56; 95% CI, 1.12-2.19) were also independently associated with postablative uTg levels.

CONCLUSION

LNR was independently associated with postoperative Tg levels in patients with PTC. Patients with high LNR were more likely to have incomplete biochemical responses after surgery.

The Role of Thyroglobulin in Preoperative and Postoperative Evaluation of Patients With Differentiated Thyroid Cancer

Thyroglobulin (Tg) is secreted by thyroid follicular cells and stored in the thyroid follicular lumen as a component of thyroid hormone. It is known that both benign and well-differentiated malignant thyroid tissue can secrete Tg. In recent years, growing lines of evidence have shown that Tg plays an important role in the diagnosis and metastasis of preoperative differentiated thyroid carcinoma (DTC). The levels of Tg, whether in the serum or in a fine-needle aspiration washout fluid, are usually viewed as an excellent indicator in the monitoring of postoperative DTC, including the guidance and evaluation of radioactive iodine ablation. Nevertheless, some factors limit the application of Tg, such as the method used to measure Tg and the presence of Tg antibodies. This review aimed to summarize the role of Tg in the preoperative and postoperative evaluation of patients with DTC, and the factors influencing Tg. This review could provide a reference for a more accurate application of Tg in patients with DTC.

Comparison of day 3 and day 5 thyroglobulin results after thyrogen injection in differentiated thyroid cancer patients

BACKGROUND

It is necessary to stimulate serum thyroid-stimulating hormone (TSH) levels either endogenously by thyroid hormone withdrawal (THW) or exogenously by administration of recombinant human TSH (rhTSH) for radioactive iodine (RAI) therapy. Thyrotropin alfa (Thyrogen) has many advantages over THW. Radiation dose to laboratory staff while drawing blood for tests on the day 5 is one of the disadvantages of preferring Thyrogen. Our aim was to compare day 3 and day 5 blood test results after Thyrogen injections.

MATERIAL AND METHOD

In our study, Thyrogen was preferred in 32 differentiated thyroid cancer patients with a mean age of 50.5 ± 12.3 years. Thyrogen was injected on day 1 and day 2 intramuscularly in all patients before I-131 was given on day 3. A total of 22 patients received 5 mCi RAI for ablation control scintigraphy and 10 patients received 100-250 mCi RAI for ablation or therapy (high-dose group). Blood tests were performed on day 3 and day 5 after Thyrogen injections.

RESULTS

Mean TSH level was 98.1 mg/dl for day 3 and 29.5 mg/dl for day 5. In the diagnostic group, thyroglobulin (Tg) and anti-Tg levels were nearly the same on day 3 and day 5. In the therapy group, day 5 Tg levels were higher than day 3.

CONCLUSION

After Thyrogen injection of two consecutive days, blood sampling might be enough on day 3. Day 5 blood sampling may not be necessary routinely for radiation protection of laboratory staff. For the diagnostic group, if Tg and anti-Tg is normal then 5 mCi imaging may not be necessary.

Biomarkers of thyroid function and autoimmunity for predicting high-risk groups of thyroid cancer: a nested case-control study

Background

A remarkable increase in the number of thyroid cancer cases has been reported in recent years; however, the markers to predict high-risk groups have not been fully established.

Methods

We conducted a case–control study (257 cases and 257 controls) that was nested in the Cancer Screenee Cohort Study between August 2002 and December 2010; the mean follow-up time for this study was 3.1 ± 2.2 years. The levels of total triiodothyronine (TT3), free thyroxine (FT4), thyroid-stimulating hormone (TSH), thyroglobulin (Tg), anti-thyroperoxidase antibody (TPOAb), and anti-thyroglobulin antibody (TgAb) were measured using samples with pre-diagnostic status. Logistic regression models were used to examine the association between thyroid function/autoimmunity and thyroid cancer risk.

Results

When the markers were categorized by the tertile distributions of the control group, the highest tertile of FT4 (OR = 1.73, 95% CI = 1.11 - 2.69) and the middle tertile of TSH (OR = 1.77, 95% CI = 1.14 - 2.74) were associated with an increased risk of thyroid cancer by multivariate analyses. In addition, an elevated risk for thyroid cancer was found in subjects with TPOAb levels above 30 IU/mL (OR = 8.47, 95% CI = 5.39 - 13.33 for 30–60 IU/mL and OR = 4.48, 95% CI = 2.59 - 7.76 for ≥60 IU/mL). Stratified analyses indicated that some of these associations differed by sex, BMI, smoking status, and the duration of follow-up.

Conclusions

This study demonstrated that the levels of biomarkers of thyroid function/autoimmunity, particularly the presence of TPOAb, might be used as diagnostic markers for predicting thyroid cancer risk. Our findings suggest that careful monitoring of thyroid biomarkers may be helpful for identifying Korean populations at high-risk for thyroid cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2407-14-873) contains supplementary material, which is available to authorized users.