Incidental papillary carcinoma in patients treated surgically for benign thyroid diseases

Cancer after thyroidectomy: a multi-institutional experience with 1,523 patients

BACKGROUND

The incidence of thyroid cancer in patients treated operatively for thyroid disease has been historically low (<5%). Previous series have not specifically addressed cancer rates in both euthyroid and hyperthyroid patients. This study examined cancer frequency in patients referred for removal of benign thyroid disease in a multi-institutional series.

STUDY DESIGN

A total of 2,551 patients underwent thyroidectomy at 3 high-volume institutions. Indeterminate/malignant fine-needle aspiration diagnosis was excluded (n = 1,028). Cancer cases were compared among 1,523 patients with Graves' disease (n = 264), nodular goiter (n = 1,095), and toxic nodular goiter (n = 164). Fisher's exact test, chi-square test, Wilcoxon rank sum, Kruskal-Wallis nonparametric t-tests, and multivariable logistic regression were used.

RESULTS

Overall, 238 (15.6%) cancers were recorded: Graves' disease (6.1%), nodular goiter (17.5%), and toxic nodular goiter (18.3%). Cancer rates were significantly different among these groups (p < 0.01) and significantly higher in nodular goiter and toxic nodular goiter vs Graves' disease (p < 0.01); no significant differences in cancer rates were noted among institutions. Overall, 275 patients had thyroiditis (18%). There was a significant association with younger age, male sex, nodular thyroids, and cancer (p < 0.05). Presence of thyroiditis or performance of preoperative fine-needle aspiration was not associated with cancer. Mean cancer size was 1.1 cm (46% >0.5 cm; 39% >1 cm). Most patients underwent total thyroidectomy (80%).

CONCLUSIONS

These data confirm higher than expected incidental thyroid cancer rates (15.6%) in the largest multi-institutional surgical series to date. Nodular thyroids, males, and young patients were more likely to harbor incidental carcinoma. These data support consideration of initial total thyroidectomy as the preferred approach for patients referred to the surgeon with bilateral nodular disease.

Clinical Review: Hashimoto's thyroiditis and papillary thyroid carcinoma: is there a correlation?

CONTEXT

The link between Hashimoto's thyroiditis (HT) and papillary thyroid cancer (PTC) has long been a topic of controversy. There are conflicting reports; some suggest that these two are positively correlated, whereas other studies report no relationship.

EVIDENCE ACQUISITION

We performed a systematic literature review of original studies that investigated the correlation between HT and PTC. The two main search engines used to identify articles were OVID Medline and PubMed. The included studies were categorized into a fine-needle aspiration biopsy (FNAB) group and an archival thyroidectomy specimen group.

EVIDENCE SYNTHESIS

There is no clear evidence to support the correlation between HT and PTC. Population-based FNAB studies report no linkage, whereas many of the studies of thyroidectomy specimens report a positive relationship. The average prevalence rate of PTC in patients with HT was 1.20% in 8 FNA studies of 18 023 specimens and 27.56% in 8 archival thyroidectomy studies of 9 884 specimens. The relative risk ratio of finding evidence of PTC in HT specimens ranged from .39 to 1.00 in the FNA group (average RR = .69) in contrast to 1.15 to 4.16 from the archival thyroidectomy studies (average RR = 1.59). In addition, there are many studies in the literature that propose a genetic link between HT and PTC involving the PI3K/Akt pathway and RET/PTC gene rearrangements.

CONCLUSION

Although limited by the lack of definitive pathology, population-based FNA studies did not find a statistically significant correlation between HT and PTC. Thyroidectomy studies, which reported a statistically significant positive correlation, are subject to selection bias. More prospective studies with longer follow-up are needed to further elucidate this relationship.

Likelihood ratio-based differentiation of nodular Hashimoto thyroiditis and papillary thyroid carcinoma in patients with sonographically evident diffuse hashimoto thyroiditis: preliminary study

OBJECTIVES

To assess the efficacy of sonography for discriminating nodular Hashimoto thyroiditis from papillary thyroid carcinoma in patients with sonographically evident diffuse Hashimoto thyroiditis.

METHODS

This study included 20 patients with 24 surgically confirmed Hashimoto thyroiditis nodules and 40 patients with 40 papillary thyroid carcinoma nodules; all had sonographically evident diffuse Hashimoto thyroiditis. A retrospective review of the sonograms was performed, and significant benign and malignant sonographic features were selected by univariate and multivariate analyses. The combined likelihood ratio was calculated as the product of each feature's likelihood ratio for papillary thyroid carcinoma. We compared the abilities of the original sonographic features and combined likelihood ratios in diagnosing nodular Hashimoto thyroiditis and papillary thyroid carcinoma by their sensitivity, specificity, and Youden index.

RESULTS

The diagnostic capabilities of the sonographic features varied greatly, with Youden indices ranging from 0.175 to 0.700. Compared with single features, combinations of features were unable to improve the Youden indices effectively because the sensitivity and specificity usually changed in opposite directions. For combined likelihood ratios, however, the sensitivity improved greatly without an obvious reduction in specificity, which resulted in the maximum Youden index (0.825). With a combined likelihood ratio greater than 7.00 as the diagnostic criterion for papillary thyroid carcinoma, sensitivity reached 82.5%, whereas specificity remained at 100.0%. With a combined likelihood ratio less than 1.00 for nodular Hashimoto thyroiditis, sensitivity and specificity were 90.0% and 92.5%, respectively.

CONCLUSIONS

Several sonographic features of nodular Hashimoto thyroiditis and papillary thyroid carcinoma in a background of diffuse Hashimoto thyroiditis were significantly different. The combined likelihood ratio may be superior to original sonographic features for discrimination of nodular Hashimoto thyroiditis from papillary thyroid carcinoma; therefore, it is a promising risk index for thyroid nodules and warrants further investigation.

Coexistence of papillary thyroid cancer with Hashimoto thyroiditis

Aims

Conflicting data have been reported with regard to Hashimoto thyroiditis (HT) and risk of malignancy. The aim of this study was to evaluate coexistence of papillary thyroid cancer (PTC) with HT.

Patients and methods

This is a retrospective cohort study in which HT was diagnosed in 452 (F/M ratio = 405:47, median age 53.5 ± 12.1 years) of 7,545 patients qualified for thyroidectomy throughout the years 2002 to 2010. Pathological reports were reviewed to identify prevalence of PTC in HT vs. non-HT patients.

Results

PTC was diagnosed in 106 of 452 (23.5 %) HT patients vs. 530 of 7,093 (7.5 %) non-HT patients (p < 0.001). Metastases to level VI lymph nodes were observed in 81 of 106 (76.4 %) patients with PTC in HT vs. 121 of 530 (22.8 %) patients with PTC in non-HT disease (p < 0.001).

Conclusions

HT was associated with a threefold increase of PTC prevalence as compared to other non-HT thyroid diseases, and the spread of PTC to level VI lymph nodes was four times more frequent in HT than in non-HT patients.

Blood neutrophil-to-lymphocyte ratio correlates with tumor size in patients with differentiated thyroid cancer

BACKGROUND AND OBJECTIVES

Inflammation has been implicated in the initiation and progression of thyroid cancer. Neutrophil-to-lymphocyte ratio (NLR) is a simple index of systemic inflammatory response, and has been shown to be a prognostic indicator in some types of cancer. The aim of this study was to examine the relationship between NLR and clinicopathological features in patients with differentiated thyroid cancer.

METHODS

Total white blood cell and differential counts of 159 patients with differentiated thyroid cancer were compared to those of 318 age- and sex-matched controls undergoing thyroidectomy for benign thyroid nodules. Clinicopathological variables, stratified by NLR tertiles, were analyzed.

RESULTS

There was no difference in NLR between patients having benign and malignant thyroid nodules (P = 0.293). Cancer patients in the higher NLR tertile had significantly larger tumor size (P = 0.004). Higher NLR was observed in patients with high American Thyroid Association (ATA) risk of recurrence.

CONCLUSIONS

High preoperative NLR was associated with increased tumor size and high ATA risk of recurrence in patients with differentiated thyroid cancer.

The role of insulin-like growth factor 1 in the development of benign and malignant thyroid nodules

OBJECTIVE

This study aims to investigate the role of IGF-1 in the development of nodular thyroid disease.

MATERIAL AND METHODS

A total number of 100 consecutive patients operated for nodular thyroid disease in our institution were included in this prospective study. In addition to classical pathological examinations, nodules and extranodular healthy tissues were sampled and immunochemically stained for IGF-1. The materials were independently evaluated using an Allred Scoring System ranging from 0 to 8. If the score was ≥1, the tissue was accepted as IGF-1 positive.

RESULTS

IGF-1 positivity was observed in 88% and 58% of the samples obtained from nodules and extranodular healthy tissues, respectively. Allred 8-unit scores were higher in benign nodules (n=89; 4.1±2.3) and papillary carcinomas (n=7; 6.7±1.3), than in extranodular healthy tissues in the same patients (2.3±2.3 and 3.3±1.9, respectively); and higher in papillary carcinomas than in benign nodules, when the scores were compared to each other (p<0.01 for all comparisons).

CONCLUSIONS

Allred 8-unit scores for IGF-1 increase in the presence of benign thyroid nodules, papillary cancer. The results of our study support the findings of previous studies demonstrating the role of IGF-1 in the development of thyroidal nodules.

Incidental versus clinically evident thyroid cancer: a 5-year follow-up study

BACKGROUND

The incidence of differentiated thyroid cancer in patients undergoing surgery for presumed benign thyroid disease (incidental thyroid cancer) is not negligible. The purpose of this study was to verify if incidental thyroid cancers have a different clinical course than the clinically evident thyroid cancer.

METHODS

A group of patients with incidental thyroid cancer (n = 95) has been compared to a control group with clinically evident thyroid cancer (n = 93). Both the histology and the outcome after a 5-year follow-up have been compared.

RESULTS

At the univariate analysis, the groups demonstrated significant differences in many pathologic features, remnant ablation (p < .001), and persistent disease (p = .006). Nevertheless, the multivariate analysis revealed that the outcome was not influenced by the preoperative or the incidental diagnosis.

CONCLUSION

Incidental thyroid cancers show a different pathological pattern when compared to clinically evident thyroid cancers. Nonetheless, the final outcome is not influenced by preoperative or postoperative diagnosis. Hence, patients with incidental thyroid cancer should follow the same postoperative protocols of patients with clinically evident thyroid cancer.

[Incidental differentiated thyroid carcinoma is less prevalent in Graves' disease than in multinodular goiter]

OBJECTIVE

Risk factors for differentiated thyroid carcinoma (DTC) are poorly understood, but serum TSH levels, thyroid nodularity, and presence of autoimmunity are well-recognized factors that modulate DTC prevalence. TSH stimulates proliferation of both normal and neoplastic follicular cells. Consequently, thyroid-stimulating immunoglobulins (TSI), because of its TSH-like action, should induce DTC progression in patients with Graves' disease (GD). The study objective was to compare the prevalence of incidental DTC in patients undergoing thyroidectomy for benign thyroid disease.

METHODS

The pathology reports of 372 patients with preoperative diagnosis of euthyroid multinodular goiter (EMG) or hyperthyroidism were reviewed. Scintigraphy results and serum TSI levels were used to diagnosed either GD or hyperactive MG (HMG) to hyperthyroid subjects. Prevalence of DTC in each category was calculated using a Chi-square test.

RESULTS

EMG, GD, and HMG were diagnosed in 221, 125, and 26 patients. There were 58 DTCs, distributed as follows [n (%)]: EMG, 49 (22.2%); GD, 8 (6.4%), and HMG, 1 (3.8%). Difference in prevalence of incidental DTC between the groups was statistically significant (p<0.001). After adjustment for age, patients with EMG had a greater DTC prevalence than GD patients, with an OR of 4.17 (p<0.001). Tumor size (mm, mean ± SD) was 6.92 ± 11.26, 1.97 ± 1.85, and 9.0 for EMG, GD and HMG respectively (p=0.017).

CONCLUSIONS

Incidental DTC was less prevalent in GD as compared to EMG irrespective of age. This finding may suggest a predisposition to develop DTC in patients with thyroid nodular disease and/or a potential effect of autoimmunity to protect against development of neoplastic disease.

Predictors of malignancy in patients with cytologically suspicious thyroid nodules

BACKGROUND

Fine needle aspiration (FNA), although very reliable for cytologically benign and malignant thyroid nodules, has much lower predictive value in the case of suspicious or indeterminate nodules. We aimed to identify clinical predictors of malignancy in the subset of patients with suspicious FNA cytology.

METHODS

We reviewed the electronic medical records of 462 patients who had FNA of thyroid nodules at our institution with a suspicious cytological diagnosis, and underwent surgery at Mayo Clinic between January 2004 and September 2008. Demographic data including age, gender, history of exposure to radiation and use of thyroid hormone was collected. The presence of single versus multiple nodules by ultrasonography, nodule size, and serum thyroid-stimulating harmone (TSH) level before thyroid surgery were recorded. Analysis of the latter was limited to patients not taking thyroid hormone or antithyroid drugs at the time of FNA.

RESULTS

Of the 462 patients, 327 had lesions suspicious for follicular neoplasm (S-FN) or Hürthle cell neoplasm (S-HCN), 125 had cytology suspicious for papillary carcinoma (S-PC) and 10 had a variety of other suspicious lesions (medullary cancer, lymphoma and atypical). Malignancy rate for suspicious neoplastic lesions (FN+HCN) was ∼15%, whereas malignancy rate for lesions S-PC was 77%. Neither age, serum TSH level, or history of radiation exposure were associated with increased malignancy risk. The presence of multiple nodules (41.1% vs. 26.4%, p=0.0014) or smaller nodule size (2.6±1.8 cm vs. 2.9±1.6 cm, p=0.008) was associated with higher malignancy risk. In patients with cytology suspicious for neoplasm (FN, HCN) malignancy risk was higher in those receiving thyroid hormone therapy than in nonthyroid hormone users (37.7% vs. 16.5%, p=0.0004; odds ratio: 3.1), although serum TSH values did not differ significantly between thyroid hormone users and nonusers.

CONCLUSION

In patients with cytologically suspicious thyroid nodules, the presence of multiple nodules or smaller nodule size was associated with increased risk of malignancy. In addition, our study demonstrates for the first time, an increased risk of malignancy in patients with nodules suspicious for neoplasm who are taking thyroid hormone therapy. The reason for this association is unknown.

Complex thyroid nodules with nondiagnostic fine needle aspiration cytology: histopathologic outcomes and comparison of the cytologic variants (cystic vs. acellular)

Management of complex thyroid nodules (CTN) is a common dilemma due to their high prevalence and frequent nondiagnostic fine needle aspiration cytology (FNAC). In order to know the rate of malignancy, we reviewed our experience about histopathologic diagnosis of CTN with nondiagnostic FNAC, and we analyzed if cytological variants of nondiagnostic FNAC indicated different histopathologic outcomes. We conducted a review of 927 consecutive aspirations performed between 2003 and 2008. We selected patients without history of radiation, with echographic CTN, and nondiagnostic FNAC, who underwent surgery. We analyzed histopathologic results and compared patients with benign and malignant nodules, and searched for differences between patients with cystic changes in FNAC (C-FNAC), and patients with acellular or only bloody FNAC (A-FNAC). Thirty-six patients were included (mean age 45.7 ± 13 years; 30 females). Four patients had malignant nodules; all were papillary carcinomas. Patients with benign nodules had a similar profile to patients with malignant nodules. Patients with C-FNAC (n = 21) were younger (41.3 ± 12.6 vs. 51.8 ± 11.2 years; P < 0.02), had more lymphocytic thyroiditis (33.3 vs. 0%; P < 0.02), a slightly higher rate of carcinoma in the nodule (14.3 vs. 6.6%; P: ns), and also of papillary microcarcinoma outside the nodule (9.6 vs. 0%; P: ns) than patients with A-FNAC. In conclusion, we report an 11.1% malignancy rate in CTN with nondiagnostic FNAC. Nodules with C-FNAC variant had a slightly higher rate of malignancy than A-FNAC, which may be in relation with younger age and higher prevalence of lymphocytic thyroiditis in this group of patients.

Hashimoto's thyroiditis is not associated with increased risk of thyroid cancer in patients with thyroid nodules: a single-center prospective study

BACKGROUND

The risk of thyroid carcinoma in patients with thyroid nodules associated with Hashimoto's thyroiditis (HT) is a debatable issue. The studies defining the true risk of thyroid malignancy are scanty and mainly depend on retrospective series. To eliminate inherent bias of retrospective studies, this prospective study was carried out to evaluate the true malignancy rate of unselected thyroid nodules in patients with HT who underwent fine-needle aspiration cytology (FNAC).

METHODS

These prospective data were gathered on all patients newly diagnosed with thyroid nodules who were sent for FNAC between May 2006 and August 2009. All patients were evaluated for the presence of HT diagnosis by measuring thyroid autoantibodies. If a patient had at least one positive thyroid autoantibody, then the patient was defined as HT with thyroid nodules. There were 164 patients (147 women and 17 men) with thyroid nodules associated with HT (HT group). There were 551 patients (432 women and 119 men) with thyroid nodules without HT (control group). All patients underwent FNAC and ultrasonography (US).

RESULTS

The malignancy rate was 1.0% in HT group (2 out of 191 nodules) and 2.7% in the control group (19 out of 713 nodules), a not significant (p = 0.19) difference. In the two cytologically malignant nodules in HT group and 19 in the control group, papillary thyroid carcinoma was diagnosed after thyroidectomy and histopathological examination. US features of nodule echogenicity, structure, margin, and Doppler flow were similar between the two groups. US features of microcalcification and absence of peripheral halo were more prominent in the nodules of the control group (p = 0.002 and p < 0.001, respectively).

CONCLUSIONS

On the basis of cytopathological criteria, thyroid nodules in patients with HT are no more likely to be malignant than in those without HT. Many of the US features of benign thyroid nodules are similar in patients with and patients without HT.