To compare the clinical outcome of patients with subclinical Cushing syndrome (SCS) due to an adrenal incidentaloma (the autonomous hypersecretion of a small amount of cortisol, which is not enough to cause clinically-evident disease) who underwent surgery or were managed conservatively. The most appropriate management of SCS patients is controversial, either adrenalectomy or close follow-up being recommended for their treatment. Over a 15-year period, 45 SCS patients were randomly selected to undergo surgery (n = 23) or conservative management (n = 22). All surgical procedures were laparoscopic adrenalectomies performed by the same surgeon. All patients were followed up (mean, 7.7 years; range, 2–17 years) clinically by 2 experienced endocrinologists 6 and 12 months after surgery and then yearly, or yearly after joining the trial, particularly monitoring diabetes mellitus (DM), arterial hypertension, hyperlipidemia, obesity, and osteoporosis. The study end point was the clinical outcome of SCS patients who underwent adrenalectomy versus those managed conservatively. All 23 patients in the surgical arm had elective surgery. Another 3 patients randomly assigned to conservative management crossed over to the surgical group due to an increasing adrenal mass >3.5 cm. In the surgical group, DM normalized or improved in 62.5% of patients (5 of 8), hypertension in 67% (12 of 18), hyperlipidemia in 37.5% (3 of 8), and obesity in 50% (3 of 6). No changes in bone parameters were seen after surgery in SCS patients with osteoporosis. On the other hand, some worsening of DM, hypertension, and hyperlipidemia was noted in conservatively-managed patients. Based on the results of this study, laparoscopic adrenalectomy performed by skilled surgeons appears more beneficial than conservative management for SCS patients complying with our selection criteria. This trial is registered with Australian Clinical Trials Registry number, ANZCTR12608000567325.

In order to identify genetic factors related to thyroid cancer susceptibility, we adopted a candidate gene approach. We studied tag- and putative functional SNPs in genes involved in thyroid cell differentiation and proliferation, and in genes found to be differentially expressed in thyroid carcinoma. A total of 768 SNPs in 97 genes were genotyped in a Spanish series of 615 cases and 525 controls, the former comprising the largest collection of patients with this pathology from a single population studied to date. SNPs in an LD block spanning the entire FOXE1 gene showed the strongest evidence of association with papillary thyroid carcinoma susceptibility. This association was validated in a second stage of the study that included an independent Italian series of 482 patients and 532 controls. The strongest association results were observed for rs1867277 (OR[per-allele] = 1.49; 95%CI = 1.30–1.70; P = 5.9×10⁻⁹). Functional assays of rs1867277 (NM_004473.3:c.−283G>A) within the FOXE1 5′ UTR suggested that this variant affects FOXE1 transcription. DNA-binding assays demonstrated that, exclusively, the sequence containing the A allele recruited the USF1/USF2 transcription factors, while both alleles formed a complex in which DREAM/CREB/αCREM participated. Transfection studies showed an allele-dependent transcriptional regulation of FOXE1. We propose a FOXE1 regulation model dependent on the rs1867277 genotype, indicating that this SNP is a causal variant in thyroid cancer susceptibility. Our results constitute the first functional explanation for an association identified by a GWAS and thereby elucidate a mechanism of thyroid cancer susceptibility. They also attest to the efficacy of candidate gene approaches in the GWAS era. Although follicular cell-derived thyroid cancer has an important genetic component, efforts in identifying major susceptibility genes have not been successful. Probably this is due to the complex nature of this disease that involves both genetic and environmental factors, as well as the interaction between them, which could be ultimately modulating the individual susceptibility. In this study, focused on genes carefully selected by their biological relation with the disease, and using more than 1,000 cases and 1,000 representative controls from two independent Caucasian populations, we demonstrate that FOXE1 is associated with Papillary Thyroid Cancer susceptibility. Functional assays prove that rs1867277 behaves as a genetic causal variant that regulates FOXE1 expression through a complex transcription factor network. This approach constitutes a successful approximation to define thyroid cancer risk genes related to individual susceptibility, and identifies FOXE1 as a key factor for its development.

The clinical and histopathological records of 149 consecutive patients with papillary thyroid microcarcinoma (PTMC), homogeneously studied and operated on by the same surgeon in the period 1990 to 2001, were reviewed. After a mean 6.5-year follow-up, three cases of loco-regional recurrence (2%) were observed. These three patients had all undergone partial thyroidectomy only and tumour relapse occurred in the residual thyroid tissue. No recurrence was observed in patients treated by total thyroidectomy and 131I. At variance with other reported series, no lymph node recurrence was observed in our series, in particular in the group of 23 patients with evidence of nodal metastases at initial diagnosis (three of whom were revealed by 131I scan after surgery). Therefore, a preventive effect of 131I treatment in our patient population can be hypothesized. However, prolonged follow-up will be necessary to clarify this. Due to the inability of current imaging modalities to select pre-operatively PTMC patients at risk for recurrence (presence of thyroid capsular invasion, multifocality and microscopic lymph node metastases), it appears reasonable to offer the patient total thyroidectomy when a pre-operative diagnosis of PTMC is reached. Moreover, the policy of our thyroid cancer centre is that, in these patients, post-surgical 131I scan should be obtained in order to detect unknown metastatic deposits, and 131I treatment should also be considered in patients with poor clinical and histopathological prognostic factors. In contrast, in patients operated on for benign thyroid disease and with delayed diagnosis of PTMC at definitive histopathological examination, re-operation might be avoided in the presence of unifocal disease without thyroid capsular invasion and with ultrasound-‘normal’ residual thyroid tissue. Close clinical and ultrasound follow-up is recommended, especially in patients who have undergone conservative surgery only.