Rising incidence of thyroid cancer in Singapore not solely due to micropapillary subtype

The impact of lymph node ratio on disease recurrence in papillary thyroid microcarcinoma

INTRODUCTION

Lymph node (LN) metastases in papillary thyroid microcarcinomas (microPTCs) are common. The lymph node ratio (LNR) has been proposed as a risk factor for recurrence in papillary thyroid cancer. However, its relevance in microPTC is undetermined.

METHODS

Patients who underwent resection of their microPTC with concomitant LN clearance between 2005 and 2018 were identified. The LNR was calculated as the ratio of positive LNs to the total number of LNs.

RESULTS

Data on 50 patients (36 female [72%]; median age 47 years [range: 19-84]) who underwent LN clearance (28 central [56%] vs 22 central + lateral [44%]) were analysed. Positive LNs were found in over two-thirds of the patients (n = 34; 68%). After a median follow-up of 61 months, 14 patients (28%) had developed recurrence. Positive LNs were not found to impact recurrence-free survival; extranodal extension and an LNR ≥ 0.26 were found to significantly increase the risk of recurrence on unadjusted analyses (p < 0.05).

CONCLUSIONS

LN metastases are frequent among patients with microPTC. A higher LNR seems to be associated with recurrence. Additional studies are needed to further clarify these findings and to assess the possible role of LNR in treatment and surveillance.

Role of Truncated O-GalNAc Glycans in Cancer Progression and Metastasis in Endocrine Cancers

Glycans are an essential part of cells, playing a fundamental role in many pathophysiological processes such as cell differentiation, adhesion, motility, signal transduction, host-pathogen interactions, tumour cell invasion, and metastasis development. These glycans are also able to exert control over the changes in tumour immunogenicity, interfering with tumour-editing events and leading to immune-resistant cancer cells. The incomplete synthesis of O-glycans or the formation of truncated glycans such as the Tn-antigen (Thomsen nouveau; GalNAcα- Ser/Thr), its sialylated version the STn-antigen (sialyl-Tn; Neu5Acα2-6GalNAcα-Ser/Thr) and the elongated T-antigen (Thomsen-Friedenreich; Galβ1-3GalNAcα-Ser/Thr) has been shown to be associated with tumour progression and metastatic state in many human cancers. Prognosis in various human cancers is significantly poor when they dedifferentiate or metastasise. Recent studies in glycobiology have shown truncated O-glycans to be a hallmark of cancer cells, and when expressed, increase the oncogenicity by promoting dedifferentiation, risk of metastasis by impaired adhesion (mediated by selectins and integrins), and resistance to immunological killing by NK cells. Insight into these truncated glycans provides a complimentary and attractive route for cancer antigen discovery. The recent emergence of immunotherapies against cancers is predicted to harness the potential of using such agents against cancer-associated truncated glycans. In this review, we explore the role of truncated O-glycans in cancer progression and metastasis along with some recent studies on the role of O-glycans in endocrine cancers affecting the thyroid and adrenal gland.

Hashimoto's thyroiditis on outcomes in papillary thyroid cancer revisited: experience from South East Asia

INTRODUCTION

The association between Hashimoto Thyroiditis (HT) and papillary thyroid cancer (PTC) remains uncertain. HT, the most common inflammatory condition of the thyroid, is postulated to increase the risk of PTC and yet confer cancer-retarding effects. In this study, we aim to evaluate the prevalence of HT in patients surgically treated for PTC and evaluate the long-term prognostic implications.

METHODS

This is a retrospective study of 521 patients with PTC who underwent hemi- or total thyroidectomy between January 2000 and December 2018 at a tertiary referral centre. Patients were categorised into two group: group A (n=402) consists of patients with PTC without HT, whereas group B (n=119) consists of patients with PTC and HT. Demographic and clinicopathological details, recurrence rates and overall survival were collected. Univariate and multivariate analyses were performed to evaluate for clinical factors associated with HT.

RESULTS

A total of 521 patients with a mean age of 46.7 years were evaluated. HT was detected in 22.8% of patients with PTC. On multivariate analysis, presence of HT was associated with a lower incidence of extrathyroidal extension (hazard ratio: 0.59, 95%confidence interval 0.37-0.95). Also, patients with HT tend to have fewer cycles of radioactive iodine and correspondingly have excellent response to treatment. However, no differences in recurrence rates and overall survival were detected.

CONCLUSIONS

One-fifth of patients with PTC have coexisting HT. These patients tend to have less-aggressive tumour features such as extrathyroidal extension. However, the effect of HT on recurrence and overall survival appears to be inconsequential clinically.

Position paper from the Japan Thyroid Association task force on the management of low-risk papillary thyroid microcarcinoma (T1aN0M0) in adults

The incidence of thyroid carcinoma has been increasing worldwide. This is interpreted as an increase in the incidental detection of papillary thyroid microcarcinomas (PTMCs). However, mortality has not changed, suggesting overdiagnosis and overtreatment. Prospective clinical trials of active surveillance for low-risk PTMC (T1aN0M0) have been conducted in two Japanese institutions since the 1990s. Based on the favorable outcomes of these trials, active surveillance has been gradually adopted worldwide. A task force on the management of PTMC in adults organized by the Japan Thyroid Association therefore conducted a systematic review and has produced the present position paper based on the scientific evidence concerning active surveillance. This paper indicates evidence for the increased incidence of PTMC, favorable surgical outcomes for low-risk PTMC, recommended criteria for diagnosis using fine needle aspiration cytology, and evaluation of lymph node metastasis (LNM), extrathyroidal extension (ETE) and distant metastasis. Active surveillance has also been reported with a low incidence of disease progression and no subsequent recurrence or adverse events on survival if conversion surgery was performed at a slightly advanced stage. Active surveillance is a safe and valid strategy for PTMC, because it might preserve physical quality of life and reduce 10-year medical costs. However, some points should be noted when performing active surveillance. Immediate surgery is needed for PTMC showing high-risk features, such as clinical LNM, ETE or distant metastasis. Active surveillance should be performed under an appropriate medical team and should be continued for life.

Papillary thyroid microcarcinoma with lung metastases: a case report and review of the literature

BACKGROUND

Distant metastasis from papillary thyroid microcarcinoma (PTMC) is rare. Here we report a case of PTMC with multiple lung metastases.

CASE PRESENTATION

A 64-year-old man presented to our hospital with abdominal pain. Computed tomography incidentally revealed multiple lung nodules. The lung tumor was histologically diagnosed as metastasis of papillary thyroid carcinoma (PTC) by core needle biopsy via thoracoscopy. The patient was referred to our department for further examination. Neck ultrasonography revealed a 0.9 cm hypoechoic nodule in the right lobe of the thyroid gland, which was diagnosed as PTC by fine-needle aspiration cytology. Subsequently, total thyroidectomy was performed, followed by radioiodine therapy. Iodine-131 (131-I) scintigraphy showed a strong accumulation in the lung metastasis. The patient presented no evidence of progression of lung metastasis for 25 months after the operation.

CONCLUSIONS

Lymph node metastasis or extraglandular extension has been reported in the few published cases of metastatic PTMC, including the present case, and the average age of these cases was 58.8 ± 12.0 years. Although active surveillance without surgical resection is expected to become a standard of care for PTMC, this case indicates that a subset of PTMC patients with risk factors may develop distant metastases. Hence, careful preoperative screening is required to avoid complications associated with completion thyroidectomy.

Factors Associated with Malignancy in Patients with Maximal Thyroid Nodules ≥2 Cm

Purpose

The relationship between large thyroid nodules and the risk of malignancy is controversial. This study aimed to examine the relationship between thyroid nodule size and the risk of malignancy of maximal thyroid nodules ≥2 cm and the risk of accompanied by occult thyroid carcinoma.

Methods

This was a retrospective study of patients who underwent near-total or total thyroidectomy for thyroid nodules from January 2016 to January 2019 at the First Affiliated Hospital,Zhejiang University School of Medicine. Clinical, biochemical, and pathological characteristics were examined for association with malignancy using univariable, multivariable, and receiver operating characteristic curve analyses.

Results

Finally, 367 patients (277 females (75.5%) and 90 males (24.5%)) with a mean age of 49.0±13.5 years were included. Multivariable logistic regression analysis showed that age (OR=0.959, 95% CI: 0.939–0.979, P<0.001), Hashimoto’s thyroiditis (OR=2.437, 95% CI: 1.162–5.112, P=0.018), the diameter of maximal nodule (small) (OR=0.706, 95% CI: 0.541–0.919, P=0.010), and punctate echogenic foci (OR=2.837, 95% CI: 1.598–5.286, P<0.001) were independently associated with malignancy. Of 223 patients who had non-suspicious malignant nodules (TI-RADS <4), 12.7% (n=29) patients showed malignancy at postoperative pathology. Only age was associated with occult PTC in the univariable analyses (OR=0.962, 95% CI: 0.934–0.991, P=0.011). When TPOAb was used as a continuous variable for statistical analysis, it showed a significant difference in the ROC curve, and the results showed TPOAb >31.4 mIU/L was more associated with occult PTC (P=0.006). A predictive model including four independent risk factors of malignancy showed an optimal discriminatory accuracy (area under the curve, AUC) of 0.783 (95% CI=0.732–0.833).

Conclusion

Relatively young age (<54.5 years), Hashimoto’s thyroiditis, the diameter of the maximal nodule, and punctate echogenic foci were independently associated with thyroid malignancy in patients with maximal thyroid nodules ≥2 cm. Young age (<54.5 years) and TPOAb >31.4 mIU/L were associated with occult PTC.

The association of preoperative thyroid-stimulating hormone level and the risk of differentiated thyroid cancer in patients with thyroid nodules: A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis was conducted to determine the value of preoperative thyroid-stimulating hormone (TSH) levels in assessing the risk of differentiated thyroid cancer (DTC) in patients with thyroid nodules.

METHODS

This meta-analysis included 23,799 subjects (15,406 non-Chinese and 8,393 Chinese) with thyroid nodules. Multivariate and individual adjusted odds ratios (OR) were calculated for a 1 mU/L increase in preoperative TSH levels to determine the risk of malignant DTC.

RESULTS

The OR for DTC in relation to preoperative TSH levels was significant in Chinese (1.25 [1.11, 1.40], Z = 3.67, p = 0.0002) and non-Chinese subjects (1.12 [1.03, 1.22], Z = 2.72, p = 0.006). The overall random-effects model indicated that there was a significantly increased risk for DTC in patients with thyroid nodules (OR 1.16 [1.06, 1.27], Z = 3.29, p = 0.007).

CONCLUSIONS

A significant association between higher TSH levels and risk of DTC was observed in both population groups investigated, with higher ORs for Chinese subjects.

Gender-specific correlation of intranodular chronic lymphocytic thyroiditis with thyroid nodule size, echogenicity, and histologically-verified cytological class of malignancy risk

No data are available on the cytologically and histologically demonstrated presence of intranodular chronic lymphocytic thyroiditis (ICLT) and on the ICLT relationship with thyroid nodule characteristics such as size, echotexture and nature (benign or malignant). We wished to fill this gap by analyzing data in a gender-specific fashion. We studied 408 thyroid nodules from 408 consecutive persons (325 females and 83 males). Nodules were isoechoic (n = 268) or hypoechoic (n = 140), ICLT +ve (n = 113 [27.7%]) or ICLT -ve (n = 295), cytologically low-risk (n = 197) or high-risk (n = 211), histologically benign (n = 263) or malignant (n = 145). ICLT prevailed in females (97/113) and in hypoechoic nodules (58/140 [41.4%] vs 55/268 [20.5%], P < 0.0001). Compared to males, females had (i) smaller nodules (18.5 ± 9.4 vs 23.3 ± 13.4 mm, P = 0.0002), a difference due to the isoechoic nodules (21.1 ± 9.8 vs 26.6 ± 14.1 mm, P = 0.0006), (ii) lower rates of high-risk nodules (161/325 [49.5%] vs 50/83 [60.2%], P = 0.082) and malignant nodules (110/325 [33.8%] vs 35/83 [42.2%] P = 0.16). ICLT +ve nodules were smaller than the ICLT -ve ones (15.4 ± 6.9 vs 20.9 ± 11.2 mm, P < 0.0001), a difference due to the isoechoic nodules (17.5 ± 6.5 vs 23.6 ± 11.7 mm, P = 0.0003). The smallest nodules were hypoechoic, cancerous and ICLT +ve nodules in males (9.5 ± 4.0 mm); the largest were isoechoic, cytologically risky and ICLT -ve in males (29.1 ± 13.2 mm). Compared to ICLT -ve nodules, malignancy prevailed in ICLT +ve nodules (55/113 [48.7%] vs 90/295 [30.5%], P = 0.0006), both in hypoechoic (37/58 [63.8%] vs 41/82 [50.0%]) and isoechoic nodules (18/55 [32.7%] vs 49/213 [23.0%]). ICLT +ve hypoechoic nodules of females and ICLT -ve hypoechoic nodules of males had the greatest rate of malignancy (67% both), while ICLT -ve isoechoic nodules of females had the lowest (19%). In conclusion, presence/absence of ICLT is associated with some sexually dimorphic characteristics of thyroid nodules. Adding the specification of ICLT positivity/negativity in cytological reports may help improving the risk of malignancy at least in some groups of thyroid nodules.