# Independent Predictive Factor of Malignancy in Thyroid Follicular Neoplasms

## Serum Thyroglobulin Level Can Be Predictive of Follicular Thyroid Cancer

It is impossible to distinguish between a benign follicular neoplasm (FN) and a malignant one using only a cytologic examination of fine-needle aspiration biopsy, and so a thyroidectomy is done to determine malignancy. Therefore, researchers wanted to examine predictive malignancy factors for FN in the hopes of reducing the number of thyroidectomies that are done to diagnose follicular carcinomas in patients.

The study, which was published in the March 2012 edition of the *Journal of Surgical Oncology* as the article “Preoperative serum thyroglobulin concentration is an independent predictive factor of malignancy in follicular neoplasms of the thyroid gland,” was a retrospective study. Researchers reviewed the charts of 388 patients with FN. There were 314 females and 74 males; the mean age was 50 years (range: 9-81 years). Those 388 patients had been surgically treated between 1988 and 2009.

Using the chi-squared test and multivariate logistic regression, predictive factors for FN malignancy were identified.

The chart review revealed that the histopathological diagnoses for these 388 patients were:

- benign goiter: 135 (35%)
- adenoma: 126 (32%)
- carcinoma: 127 (33%)

The multivariate logistic regression showed that independent predictors of malignancy were age (odds ratio [OR] 1.88; p = 0.008), solitary tumor (OR 1.72; p = 0.037), and thyroglobulin (Tg) concentration (OR 2.36; p = 0.001).

A malignant FN was more common in patients who were > 45 years, had a solitary tumor, and pre-operative serum Tg level of > 400 ng/mL.

The researchers concluded that taking the serum Tg concentration may be helpful in trying to diagnose if a patient has a malignant FN. Tg concentration, along with age and presence of a solitary tumor, is an independent predictor of malignancy, so checking the concentration may reduce the number of patients who need to undergo diagnostic thyroidectomies.

### Sources

- Petric R, Perhavec A, Gazic et al. Preoperative serum thyroglobulin concentration is an independent predictive factor of malignancy in follicular neoplasms of the thyroid gland.
*J Sur Oncol*. 2012;105(4): 351-6. doi: 10.1002/jso.22030.