The Impact of BRAF V600E Mutation Allele Frequency on the Histopathological Characteristics of Thyroid Cancer

BACKGROUND

A BRAF V600E mutation in papillary thyroid cancer (PTC) has been shown to be associated with aggressive behavior. Nevertheless, not all BRAF V600E PTCs behave aggressively. Allele frequency (AF) is the number of mutated molecules divided by the total number of wild-type molecules at a specific location in the genome. The relationship between BRAF V600E AF and the histopathological features of thyroid malignancies is not well understood. We hypothesized that the BRAF V600E AF will correlate directly with aggressive histopathological behavior. The aim of this study was to examine this relationship.

METHODS

A retrospective chart review was performed for patients treated for BRAF V600E thyroid malignancies from 2019 to 2022 at McGill University tertiary care hospitals (n = 317). Patients with BRAF V600E-positive malignancies that included information on AF were included (n = 44). The correlation between AF and tumor histopathological features was analyzed.

RESULTS

Out of the 44 nodules with a BRAF V600E mutation, those with aggressive features of PTC had a mean AF of 25.8%, which was significantly higher than the non-aggressive group with a mean AF of 10.25% (p = 0.020). Additionally, there was a statistically significant difference in mean AF between patients with a positive sentinel LN (29%) and those with a negative sentinel LN (17.8%) (p = 0.021). Classical PTC was present in 29.5% (13/44) of nodules, with a mean AF of 15.6%. The tall cell subtype was found in 64% (28/44) of nodules, with a mean AF of 23%. Solid and hobnail subtypes were less common in this study, and there was no statistically significant relationship between AF and histopathological subtypes (p = 0.107). Nodules smaller than 1cm had a mean AF of 13.3%, while nodules ranging from 1 2cm had a mean AF of 20.6%, and those larger than 2cm had a mean AF of 27.7%. However, no statistical difference was observed between AF and nodule size (p = 0.160).

CONCLUSION

In this study, BRAF V600E mutations in conjunction with AF help to determine whether thyroid malignancies will display aggressive behavior. This pre-operative finding can help thyroid specialists to determine the extent of thyroidectomy and whether lymph node dissection is required.

The Difference in Clinical Behavior of Gene Fusions Involving RET/PTC Fusions and THADA/IGF2BP3 Fusions in Thyroid Nodules

BACKGROUND

Molecular testing has been used as an adjunct to morphological evaluation in the workup of thyroid nodules. This study investigated the impact of two gene fusions, RET/PTC and THADA/IGF2BP3, that have been described as oncogenic events in thyroid neoplasms.

METHODS

We performed a retrospective, single-centered study at a McGill University teaching hospital in Montreal, Canada, from January 2016 to August 2021. We included patients who underwent surgery for thyroid nodules that pre-operatively underwent molecular testing showing either RET/PTC or THADA/IGF2BP3 gene fusion.

RESULTS

This study included 697 consecutive operated thyroid nodules assessed using molecular testing, of which five had the RET/PTC fusion and seven had the THADA/IGF2BP3 fusion. Of the five nodules in the RET/PTC group, 100% were malignant and presented as Bethesda V/VI. Eighty percent (4/5) were found to have lymph node metastasis. Twenty percent (1/5) had extrathyroidal extensions. Sixty percent (3/5) were a diffuse sclerosing variant of papillary thyroid carcinoma, and the rest were the classical variant. Of the seven THADA/IGF2BP3 nodules, all presented as Bethesda III/IV and 71.4% (5/7) were malignant based on the final pathology analysis, and 28.6% (2/7) were NIFTP. All the THADA/IGF2BP3 fusion malignancies were a follicular variant of papillary thyroid carcinoma. None had lymph node metastasis or displayed extrathyroidal extensions.

CONCLUSIONS

RET/PTC nodules presented as Bethesda V/VI and potentially had more aggressive features, whereas THADA/IGF2BP3 nodules presented as Bethesda III/IV and had more indolent behavior. This understanding may allow clinicians to develop more targeted treatment plans, such as the extent of surgery and adjuvant radioactive iodine treatment.

Development and validation of the modified index of fragility in head and neck cancer surgery

BACKGROUND

This study aims to develop and validate, a clinically useful modified index of fragility (mIFG) to identify patients at risk of fragility and to predict postoperative adverse events.

METHOD

An observational study was performed using the American College of Surgeons National Surgical Quality Improvement Program database, from 2006 to 2018. All patients undergoing nonemergency head and neck cancer surgery were included. A seven-item index (mIFG) was developed using variables associated with frailty, cachexia, and sarcopenia, drawn from the literature (weight loss, low body mass index, dyspnea, diabetes, serum albumin, hematocrit, and creatinine). Multivariable logistic regression was used to model the association between mIFG, postoperative adverse events and death. A validation cohort was then used to ascertain the diagnostic accuracy of the mIFG.

RESULTS

A total of 23,438 cases were included (16,407 in the derivation group and 7031 in the validation group). There was a total of 4273 postoperative major adverse events (AE) and deaths, 1023 postoperative pulmonary complications and 1721 wound complications. Using the derivation cohort, the 7-item mIFG was independently associated with death, major AEs, pulmonary and wound complications, when controlling for significant covariates. The mIFG predicted death and major adverse events using the validation cohort with an accuracy of 0.70 (95% CI: 0.63-0.76) and 0.64 (95% CI: 0.63-0.66), respectively. The mIFG outperformed the modified Frailty index.

CONCLUSION

The modified index of fragility is a reliable and easily accessible tool to predict risk of postoperative adverse events and death in patients undergoing head and neck cancer surgery.

Coexisting Molecular Alterations Increase the Risk of Malignancy in Thyroid Nodules with Copy Number Alterations

Molecular mutations and alterations play a role in thyroid tumorigenesis. Different alterations are associated with different clinical and pathological characteristics. Copy number alterations (CNAs) are known to be present in some thyroid tumors; however, their idiosyncratic clinicopathological implications are not yet well elucidated. A retrospective chart review was performed to identify patients with CNAs on pre-operative molecular testing results who subsequently underwent surgical treatment between January 2016 and April 2022 at McGill University teaching hospitals. Of the 316 patients with thyroid nodules who opted for molecular testing with ThyroSeqV3 followed by surgery, 67 (21.2%) nodules were positive for CNAs, including 23 Bethesda III, 31 Bethesda IV, 12 Bethesda V and 1 Bethesda VI nodules. On surgical pathology, 29.9% were benign and 70.1% were malignant or non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Among those that were malignant/NIFTP, 17.02% were considered to be aggressive cancers. The presence of other molecular alterations was found to be an independent predictor of malignancy in multivariate analysis (OR = 5.087, 95% C.I. = 1.12-23.04, p = 0.035). No unique factor was correlated with aggressiveness; however, CNA-positive thyroid nodules that were associated with high-risk mutations such as BRAF V600E, TP53, NTRK1/3 fusion, or PTEN mutation with high allele frequency (AF) ended up being aggressive cancers. Most of the CNA-positive thyroid nodules resulted in follicular patterned tumors in 41 (65.2%) cases and oncocytic tumors in 20 (29.9%) cases. This study demonstrates that 70.1% of surgically resected thyroid nodules with CNAs were malignant/NIFTP. Most CNA-positive thyroid nodules were either oncocytic patterned tumors or follicular patterned tumors. Furthermore, CNA-positive thyroid nodules were more likely to be malignant if they were associated with other molecular alterations or mutations.

Prognostic Indicators of EIF1AX-Mutated Thyroid Tumor Malignancy and Cancer Aggressiveness

The risk of malignancy (ROM) of EIF1AX-mutated thyroid nodules has been theorized to be contingent on the position of the mutation within the gene and the presence of co-existing mutations. However, due to EIF1AX's low mutation frequency, sample sizes currently reported in the literature are too diminutive to appraise the clinical utility of molecular diagnostic testing. The objective of this study was to elucidate prognostic indicators of EIF1AX-mutated thyroid tumors and cancer aggressiveness by examining a large cohort of cytologically indeterminate thyroid nodules (CITNs) that underwent molecular testing and subsequent surgical resection. This is a multicenter study involving 764 subtotal and total thyroidectomy patients that underwent preoperative molecular testing at two quaternary care hospitals. A five-year retrospective review was performed on the 42 charts of patients that opted for surgery following a positive EIF1AX mutation on ThyroseqV3 results from January 2018 to May 2022. Patient demographics, cytopathology results, molecular testing results, and postoperative histopathology were reviewed. Of the 42 surgically resected nodules that harbored an EIF1AX mutation, 16 (38.1%) were benign, six (14.3%) were non-invasive follicular thyroid neoplasms with papillary-like nuclear features (NIFTPs) or well-differentiated thyroid neoplasms of uncertain malignant potential (WDT-UMPs), and 20 (47.6%) were malignant. An isolated EIF1AX mutation conferred a ROM of 47.6%, whereas the ROM for nodules with at least one additional molecular alteration was 72.7%. The ROM increased to 100% for nodules with at least one additional molecular alteration and the A113_splice site mutation. Six malignant nodules were aggressive, with five having variegated components of poorly differentiated thyroid carcinoma (PDTC). EIF1AX-mutated thyroid nodules are more susceptible to malignancy in the presence of the A113_splice site mutation and when co-mutated with RAS and/or TP53. This deleterious amalgam is associated with aggressive disease and renders these nodules PDTC. A preoperative molecular test finding of an EIF1AX mutation can be a useful tool for thyroid specialists to optimize clinical management.

EIF1AX mutation in thyroid tumors: a retrospective analysis of cytology, histopathology and co-mutation profiles

Background

The EIF1AX mutation has been identified in various benign and malignant thyroid lesions, with a higher prevalence in poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma, especially when combined with RAS or TP53 mutation. However, data and clinical significance of EIF1AX mutations in thyroid nodules is still limited. We investigated the prevalence of EIF1AX mutations and co-mutations in cytologically indeterminate thyroid nodules at our institution.

Methods

A 5-year retrospective analysis was performed on surgically resected thyroid nodules with identified EIF1AX mutations on molecular testing with ThyroseqV3®. Mutation type and presence of co-mutations were correlated with histopathologic diagnosis and clinical characteristics. Histopathology diagnoses were subsequently categorized as benign, borderline, malignant or aggressive malignant (≥ 10% PDTC component). Chi-square test was used to compare the malignancy associations of the: 1) A113_splice mutation compared to non-A113_splice mutations 2) singular A113_splice mutations compared to singular non-A113_splice mutations. Fisher’s Exact Test was used to determine the association of A113_splice mutation with aggressive malignancies compared to non-A113_splice mutations. A p value of 0.05 or less was considered statistically significant.

Results

Out of 1583 patients who underwent FNA, 621 had further molecular testing. 31 cases (5%) harbored EIF1AX mutations. Of these cases, 12 (38.7%) were malignant, 2 (6.5%) were borderline, and 17 (55%) were benign. 4/31 cases (13%) were aggressive malignant (≥ 10% PDTC component). The most prevalent mutation was the A113_splice mutation at the junction of intron 5 and exon 6 (48%). All other mutations, except one, were located at the N-terminal in exon 2. 7/31 cases (22.6%) harbored ≥ 1 co-mutation(s), including 4 RAS, 3 TP53, 1 TERT and 1 PIK3CA, with 86% of them being malignant. All 4 nodules with RAS co-mutations were malignant including one PDTC.

Conclusion

Our study reports the largest cohort of EIF1AX mutations in Bethesda III/IV FNA samples with surgical follow-up to our knowledge. The presence of the EIF1AX mutation confers a 45.2% risk of malignancy (ROM) or borderline after surgery. However, the coexistence of EIF1AX mutations with other driver mutations such as RAS, TERT or TP53 conferred an 86% ROM. While 55% of thyroid nodules were benign at the time of surgery, the possible malignant transformation of these nodules, had they not been resected, is unknown. Finally, 13% of the nodules with EIF1AX mutations were aggressive with a significant PDTC component. These findings can further aid in clinical decisions for patients with thyroid nodules.

Graphic Abstract

Molecular Testing for Thyroid Nodules: The Experience at McGill University Teaching Hospitals in Canada

In the past few decades, molecular characterization of thyroid cancer has made significant progress and is able to identify thyroid-cancer-related molecular markers that can then be applied clinically for improved decision making. The aim of this review is to provide a general overview about the molecular markers (mutations and alterations) of thyroid cancers, present several molecular tests, and discuss the clinical applications of identifying these markers supported by the clinical experience of several high-volume thyroid cancer specialists at the McGill university hospitals in Montreal, Canada. Our group experience showed that molecular testing can reclassify more than half of the patients with indeterminate thyroid nodules (Bethesda III and IV) into benign and spare these patients from unnecessary diagnostic surgery. Furthermore, it can help optimize the initial management in thyroid cancers with no evidence of high risk of recurrence of disease preoperatively. While routine molecular testing is not firmly established for thyroid FNA specimens that are suspicious or positive for malignancy (Bethesda V and VI), knowledge of a thyroid nodule’s molecular risk group profile in such cases, together with its clinical and radiologic features, can help select the optimal surgical options (lobectomy versus upfront total thyroidectomy and central neck dissection), as demonstrated by our studies.

Framing Concerns about Body Image during Pre- and Post-Surgical Consultations for Head and Neck Cancer: A Qualitative Study of Patient–Physician Interactions

Patients with head and neck cancer report high unmet psychosocial needs as they undergo lifesaving treatments that can significantly alter their appearance and cause functional impairments. This qualitative analysis of recordings of 88 pre- and post-surgical consultations involving 20 patients respond to the need for empirical studies of patient–provider conversations about body image concerns. It indicates that the emphasis on concerns about survival, cure, and physical recovery during clinical consultations may leave concerns about the impacts of surgery on appearance and function unexplored and even silenced. The interviews with patients and medical team members that complement the analysis of the recordings suggest that an emphasis on survival, cure, and physical recovery can respond to the need for reassurance in the context of serious illness. However, it can also be problematic as it contributes to the silencing of patients’ concerns and to a potential lack of preparedness for the consequences of surgery. The results of this study can contribute to raising surgeons’ awareness of the interactional dynamics during clinical consultations. Moreover, the results highlight the unique role that surgeons can play in validating patients’ psychosocial concerns to support patients’ rehabilitation in both physical and psychosocial domains.

Mutational status may supersede tumor size in predicting the presence of aggressive pathologic features in well differentiated thyroid cancer

Background

In clinical practice, thyroid tumor size plays a critical role in the staging of thyroid malignancies and in the selection of nodules that should undergo ultrasound-guided fine-needle aspiration. Thyroid tumor size is influenced by the elapsed time since the beginning of oncogenesis and by the presence of somatic mutations driving growth, such as BRAF^V600E mutations, associated with aggressive phenotypes, and RAS-like mutations, associated with more indolent behavior. Although large nodules are often considered to be more alarming, the true impact of tumor size on prognosis remains controversial. The aim of this study was to assess the relationship between mutational status, tumor size and aggressiveness, with emphasis on BRAF^V600E and RAS-like mutations.

Method

We conducted a multicentric retrospective chart review in Montréal, Canada, of all patients who underwent thyroid surgery between January 2016 and December 2020, with well-differentiated thyroid cancer on final pathology, and who had undergone molecular testing revealing the presence of BRAF^V600E mutations or RAS-like mutations (NRAS, HRAS or KRAS).

Results

We included 214 cases. There were 117 (54.7%) cases of BRAF^V600E and 97 (45.3%) cases of RAS-like mutations. The BRAF^V600E group was statistically associated with a smaller mean tumor size when compared with the RAS group of 1.55 cm and 2.04 cm, respectively. In a multivariate model, tumors with BRAF^V600E mutations were also more likely to display aggressive pathological features, including extra-thyroidal extension, lymph node metastasis, columnar cell features, tall cell histology, or hobnail histology (OR 26.69; 95% CI 11.15–70.81). In contrast, tumor size was not associated with pathologic aggressive features on multivariate analysis (OR 0.81; 95% CI 0.54–1.22).

Conclusion

This study demonstrates that thyroid tumors expressing BRAF^V600E mutations correlate with aggressive pathologic features more than tumors expressing RAS-like mutations. When comparing tumors with BRAF^V600E and RAS-like mutations, the former were found to be smaller. As a result of this finding, this study suggests that molecular alterations may better predict aggressive pathologic features than the size of the tumor.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40463-022-00559-9.

BRAF V600E mutation is associated with aggressive features in papillary thyroid carcinomas ≤ 1.5 cm

Background

While some studies suggest that the BRAF V600E mutation correlates with a high-risk phenotype in papillary thyroid microcarcinoma (PTMC), more evidence is necessary before this mutation can be used to help guide decision making in the management of small thyroid nodules. This study investigated whether BRAF V600E mutation is associated with aggressive features in PTMC (≤ 1 cm) and small PTC (1–1.5 cm).

Methods

Retrospective chart review was performed on 121 patient cases. Patients who underwent thyroid surgery for PTMC (≤ 1 cm) or small PTC (1–1.5 cm) were included if molecular testing was done for BRAF V600E mutation. Two study groups were created based on tumour size: PTMC (n = 55) and small PTC (n = 66). The groups were analysed for the presence of a BRAF V600E mutation and aggressive features, including macroscopic extrathyroidal extension (ETE), lymph node metastasis (LNM), and high-risk histological features (tall cell, columnar cell, hobnail, solid/trabecular, and diffuse sclerosing). The Fischer exact test was used to calculate statistical significance.

Results

BRAF V600E mutations were detected in 43.6% of PTMC and 42.4% of small PTC. Of the mutated PTMC nodules, 54.1% demonstrated aggressive characteristics as compared to 19.4% of the non-mutated PTMCs (p = 0.010). Of the mutated small PTC tumours, 82.1% had aggressive features. In contrast, 28.9% of the non-mutated small PTCs showed aggressive features (p < 0.001).

Conclusions

Our findings demonstrate an association between a BRAF V600E mutation and aggressive features in PTMC (≤ 1 cm) and small PTC (1–1.5 cm). Therefore, determining the molecular status of these thyroid nodules for the presence of BRAF V600E can help guide patient management.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40463-021-00543-9.

The Role of the ThyroSeq v3 Molecular Test in the Surgical Management of Thyroid Nodules in the Canadian Public Health Care Setting

Background: Although the current gold standard for diagnosing thyroid nodule malignancy is ultrasound-guided fine-needle aspiration (FNA) cytology, about 20-25% of cytological evaluations are considered indeterminate for malignancy. This limitation has led to the emergence of next-generation sequencing panels, for example, ThyroSeq v3 (TSv3), which recognize highly diagnostic genetic mutations of common thyroid carcinomas in FNA samples and classify them as test-negative or test-positive, helping optimize treatment for indeterminate thyroid nodules (ITNs). Our goals were to evaluate the benign call rate (BCR) of TSv3 and assess its diagnostic performance and clinical utility while highlighting the points of consideration for a public Canadian institution. Methods: This is a single-center study conducted at the Royal Victoria Hospital (McGill University Health Centre) in Montreal, Canada, between January and February 2019. Patients were offered TSv3 following the McGill algorithm for ITN workup, a novel protocol developed at our institution to select only diagnostic surgery candidates to minimize waste of public resources, considering the single-payer health care system. Patient demographics, cytopathology results, TSv3 data, treatment plan, and final histopathology result were reviewed. Results: A total of 50 ITNs underwent TSv3 testing; molecular analysis yielded 20 (40%) "positive" results and 24 (48%) "negative" results. Six (12%) results were classified as "currently negative" or "negative but limited." "Currently negative" results indicate a low-risk mutation that alone is insufficient for development of a malignant lesion. "Negative but limited" results indicate a sample that is nondiagnostic for malignancy due to low cell count. BCR was calculated as ("negative" and "currently negative")/total, resulting in a BCR of 58%. Twenty-three (46%) patients were scheduled for surgery and 27 (54%) patients continued with surveillance. Ninety-one percent (20 of 22) of the resected target nodules were malignant on final pathology. Conclusions: TSv3 proved beneficial in classifying ITNs as positive or negative, avoiding surgery in the latter cases. We found a lower reduction rate in surgery and BCR than the previously published studies, which is attributable to the criteria of the McGill algorithm. In the Canadian public health care system, preventing unnecessary surgery represents significant cost savings for the provincial government while also improving patient quality of life.

Carcinoembryonic antigen levels correlated with advanced disease in medullary thyroid cancer

Background

Medullary thyroid cancer (MTC) cells are capable of secreting various tumor markers including calcitonin and carcinoembyronic antigen (CEA). The purpose of this study is to determine whether abnormal CEA levels may be used as a tumor marker to predict the severity of disease in MTC.

Methods

A retrospective analysis was completed for 33 patients with MTC who had preoperative serum CEA levels. Univariate and multivariate analyses were used to quantify the relationship between serum CEA levels and tumor stage and prognosis.

Results

On multivariate analysis, elevated preoperative CEA levels were significantly associated with the size and stage of tumor, distant metastasis, decreased biochemical cure, and mortality. There was a significant association between tumor size greater than 37 mm and elevated CEA levels (> 271 ng/ml). There was also a positive correlation with increased cancer stage (> 377 ng/ml), distant metastasis (> 405 ng/ml), and contralateral compartment location of lymph node metastasis (> 162 ng/ml). When pre-operative CEA levels are > 500 ng/ml, patient mortality was 67%.

Conclusion

In this study, both pre-operative calcitonin and CEA levels were significantly correlated with the extent of disease in MTC. While calcitonin has a linear relationship with disease progression, abnormal CEA levels were a better indicator of advanced disease. CEA levels > 271 ng/ml are significant for advanced tumor size and staging, metastasis to the central compartment, and decreased chance of biochemical cure. CEA levels greater than 500 ng/ml are associated with significant patient mortality.

Re-visiting the ATA 2015 sonographic guidelines - who are we missing?: A retrospective review

BACKGROUND

The American Thyroid Association published revised guidelines in 2015 on the management of differentiated thyroid cancer in adults. One of the key changes introduced in the revision proposes that diagnostic biopsy be based on ultrasound findings (i.e. size and nodule characteristics). The overall effect of these changes results in fewer nodules requiring biopsy. This study was conducted to determine if the changes to the guidelines will result in overlooked thyroid cancers, specifically malignancies with aggressive characteristics measuring between 1 and 1.49 cm.

METHODS

Patients (n = 2083) with thyroid nodules who underwent total or subtotal/hemi thyroidectomy with or without neck dissection by a single surgeon between 2006 and 2016 were retrospectively enrolled. Demographic information and nodule characteristics were collected for all patients. Ultrasonography and final pathology reports were reviewed for patients with thyroid nodules between the sizes of 1-1.49 cm (n = 155).

RESULTS

45% (n = 70) of patients with nodules between 1 and 1.49 cm were "low suspicion" nodules according to ultrasound. 47 of these nodules contained malignancies on final histopathological examination, 100% of which were of the papillary subtype. 21% (n = 10) of these malignant nodules demonstrated extrathyroidal extension and 34% (n = 16) were associated with regional metastases.

CONCLUSIONS

Reliance on sonographic patterns alone could result in missed cancer diagnoses in patients with thyroid nodules measuring between 1 and 1.49 cm. Moreover, a portion of these malignancies may be associated with aggressive features. The effect of this finding on long-term outcomes is unclear.

The role of repeat fine needle aspiration in the management of indeterminate thyroid nodules

Background

Management decisions are not straightforward when the Ultrasound Guided Fine Needle Aspiration (USFNA) demonstrates a Bethesda score of either category III or IV, and a diagnostic hemi-thyroidectomy or a repeat USFNA (r-USFNA) could be performed. The aim of this study is to assess the effectiveness of r-USFNA in the management of indeterminate thyroid nodules by evaluating the likelihood of obtaining a definite diagnosis.

Methods

We reviewed the medical records of all patients with thyroid nodules between 2011 and 2015 at the Jewish General Hospital (Montreal, Canada). Three hundred fifty-one patients who had undergone a surgical procedure (hemi or total thyroidectomy) and a diagnosis of B3 or B4 on the primary USFNA (p-USFNA) were included in the study. Ninety-six of the included patients also had a repeat USFNA prior to the surgery. Demographic data, type of procedure, and McGill Thyroid Nodule Score (MTNS) were obtained from the medical records. Malignancy rates were calculated based on the final surgical histopathology report.

Results

Upon r-USFNA, an average 76 % of patients did not change Bethesda categories, 7.4 % downgraded to a benign category. The results showed that, on an average 17.3 % of patients with p-USFNA of B3 and 20 % of patients with p-USFNA of B4, upgraded to a malignant or suspicious for malignancy category, thus changing the clinical management to total thyroidectomy. Our data demonstrates that r-USFNA facilitates choosing the correct surgery of total thyroidectomy in about 20 % of nodules that have upgraded from B3/B4 to a more definite malignant category.

Conclusions

r-USFNA in patients with indeterminate diagnoses (B3 or B4) increases categorization into more definite categories. Approximately 20 % of patients are found to have malignant thyroid nodules and suspicious for malignancy thyroid nodules upon repeating the biopsy, hence a diagnostic hemi-thyroidectomy was avoided and a more definitive surgery could be performed. Furthermore, repeat USFNA results in a fewer number of hemi-thyroidectomy and completion thyroidectomy procedures.

Can preoperative thyroglobulin antibody levels be used as a marker for well differentiated thyroid cancer?

Background

It has been reported that thyroglobulin antibody are more frequently elevated in patients with thyroid cancercompared to general population. This study aims at evaluating whether preoperative thyroglobulin antibody (TgAb) levels increase the likelihood that a thyroid nodule is malignant.

Methods

A retrospective review of 586 patients who underwent thyroidectomy was conducted. Demographic data, TgAb levels, and final histopathology were recorded. Patients were divided into two groups: TgAb positive (defined as TgAb ≥ 30 IU/ml) and TgAb low/negative (defined as TgAb < 30).

Results

Preoperative TgAb levels were available in 405 patients. There were 353 (87 %) patients in the TgAblow/negative group (malignancy rate: 50.42 %) and 52 (13 %) patients in the TgAb positive group (malignancy rate: 65.38 %). The sensitivity, specificity, positive predictive value and negative predictive value of TgAb ≥ 30 IU/ml for thyroid malignancy were 16.04 %, 90.67 %, 65.38 % and 49.58 %, respectively. The relative risk of having a malignant thyroid nodule when the TgAb titers were≥30 IU/ml was 1.30 (CI1.04-1.62) and the odds ratio was 1.86 (CI 1.01-3.41). Both the Pearson chi-square test (p = 0.024) and Fisher’s exact test (p = 0.017) yielded statistical significance between the two groups.

Conclusions

In this study, patients with preoperative TgAb ≥ 30 IU/ml had a higher rate of malignancy when compared topatients with TgAb < 30 IU/ml. This suggests that an elevated TgAb level may indicate that a thyroid nodule is at an increased risk for malignancy.

Seasonal Difference in Postthyroidectomy Hypocalcemia

Objective

Hypocalcemia following thyroidectomy often prolongs hospital stay and is potentially life-threatening. The objective of this study is to determine whether the season when thyroidectomy is performed is associated with postoperative hypocalcemia.

Study Design

Retrospective case series of patients undergoing thyroid surgery from 2009 to 2015.

Setting

Tertiary care academic institution in Montreal, Canada.

Subjects and Methods

A consecutive sample of 823 patients undergoing thyroidectomy by a single high-volume otolaryngologist for a suspected or confirmed thyroid malignancy. Patient demographics, procedure type, calcium and vitamin D supplementation, and seasonal rate of hypocalcemia postthyroidectomy were calculated and compared.

Results

Average seasonal rates of postthyroidectomy hypocalcemia in the winter, spring, summer, and autumn were, respectively, 8.3% (8 of 216), 7.3% (12 of 165), 1.5% (3 of 201), and 3.5% (8 of 228; P < .005). Patients operated in the winter were 5.6 times more likely to develop hypocalcemia as compared with those in the summer ( P < .01; 95% confidence interval: 1.7-18.7). In a multiple regression analysis factoring in season when surgery was performed, procedure type, and preoperative vitamin D/calcium supplementation, surgery occurring in the winter predicted a hypocalcemia event (correlation coefficient [SE]: 0.72 [0.024], P = .026; 0.006 [0.025], P = .81; 0.004 [0.019], P = .82, respectively).

Conclusion

In this study, patients undergoing thyroidectomy in the winter months were more likely to develop postoperative hypocalcemia when compared with those operated in the summer. Further studies are needed to understand the role of vitamin D in the observed seasonal difference in hypocalcemia rates.

Preoperative vocal cord paralysis and its association with malignant thyroid disease and other pathological features

Background

Vocal cord paralysis (VCP) is found in both benign and malignant thyroid disease. This study was performed to determine if the presence of preoperative VCP predicts malignancy.

Methods

A retrospective analysis was performed on a cohort of 1923 consecutive patients undergoing thyroid surgery. The incidence of preoperative VCP was recorded. Patient and nodule characteristics were correlated with final pathology.

Results

1.3 % of our cohort was found to have preoperative VCP. Malignant pathology was discovered in 76 % of patients with preoperative VCP. Among these patients, 72 % had a left sided paralysis. 10.5 % of patients with preoperative VCP had perineural invasion (PNI) on final pathology, compared to 1.1 % of patients with normal VC function.

Conclusion

Preoperative VCP appears to be a strong, though not an absolute, indicator of malignancy. Most VCP were on the left side. Assessing for preoperative VCP is crucial in all patients who need thyroid surgery, as even benign nodules can be accompanied by preoperative vocal cord paralysis.

Frozen section analysis and sentinel lymph node biopsy in well differentiated thyroid cancer

Background

The aim of this study is to prospectively review the role of sentinel lymph node (SLN) biopsy in the management of well differentiated thyroid carcinoma (WDTC), and to determine the efficacy of intraoperative frozen section analysis at detecting SLN metastasis and central compartment involvement.

Methods

The SLN biopsy protocol using 1% methylene blue was performed in 300 patients undergoing thyroidectomy for WDTC. A limited pretracheal central compartment neck dissection (CCND) was performed on all patients. Lymph nodes staining blue were considered as SLN’s. Both frozen and permanent section analyses were performed.

Results

SLN’s with metastasis were found in 14.3% (43/300) of cases. Of this, 11% (33/300) were positive on intraoperative frozen section analysis. Frozen section results failed in predicting central compartment involvement in 15 cases (5%) whereas central neck compartment involvement was missed in 5 cases (1.7%) when based on permanent section results. On frozen section analysis, the sensitivity, specificity, positive predictive value and negative predictive value (95% CI) of our SLN biopsy technique aiming to remove all disease from the central compartment was 68.8% (53.6-80.9), 100% (98.1-100), 100% (87.0-100) and 94.4% (90.7-96.7) respectively with P < 0.0001. On permanent section analysis, the values were 89.6% (76.6-96.1), 100% (98.1-100), 100% (89.8-100), and 98.1% (95.3-99.3) with P < 0.0001.

Conclusion

This data series demonstrates that patients with WDTC have positive SLN’s in 14.3% of cases. Moreover, when the SLN’s are negative for metastasis on frozen section, the central compartment was disease-free in 94.4% of cases. Finally, this study shows that 23.3% of positive SLN’s were false negatives on intraoperative frozen section. According to this data, SLN involvement is an accurate predictor of central compartment metastasis, however surgeons should use caution when relying on intraoperative frozen section to determine whether to perform a CCND.

Value of thyroid incidentalomas on positron emission tomographic scans among thyroidectomy patients

OBJECTIVES

To evaluate the preoperative predictive value of a positive positron emission tomographic (PET) scan with respect to malignancy in future thyroidectomy candidates, particularly when the fine-needle aspiration biopsy (FNAB) results in indeterminate findings, and to establish the efficiency with which this can be incorporated as a preoperative marker and potentially contribute to a standardized scoring system for thyroid nodule patients.

METHODS

This retrospective study examined 1048 thyroidectomy patients, of whom 45 underwent PET with computed tomography for unrelated reasons, among which 13 results were focally positive. The final pathology was evaluated and compared to this result to determine the correlation.

RESULTS

All patients with positive PET results were shown postthyroidectomy to have a thyroid malignancy (13 of 13), corresponding to a positive predictive value of 100%. There was no correlation between a negative PET scan and malignancy, however. When integrating the PET scan criteria in the McGill Scoring System, 4 of these 13 were shifted into a high chance of malignancy group, allowing a more accurate assessment of their risk than they might have previously received.

CONCLUSION

In comparison with previous data, our results indicate a strong relationship between a positive PET scan and malignancy. If available and used in conjunction with the other preoperative diagnostic tools (outlined by the McGill Thyroid Nodule Scoring System), this test can hold significant merit in determining a therapeutic strategy, particularly in the face of an indeterminate FNAB.

Orbital decompression: cadaver study

BACKGROUND

Patients with Graves' ophthalmopathy may need surgical treatment to alleviate ophthalmologic complications. The degree of reduction in proptosis following surgical intervention remains difficult to predict.

OBJECTIVES

To elaborate a human model using cadaver orbits to study surgical management of Graves' ophthalmopathy. To evaluate quantitatively the contribution of each orbital wall decompression and their combinations in reduction in proptosis. To improve the ability to predict the degree of proptosis reduction according to the wall(s) chosen for decompression.

METHODS

Artificial exophthalmos was created in 12 cadavers' orbits by injecting a polysaccharide gel in the peribulbar and retrobulbar tissues. Proptosis reduction was measured following successive orbital decompression.

RESULTS

Decompression of one wall produced a nonstatistical significant reduction in proptosis. The combination of the medial and lateral walls significantly reduced the proptosis by a mean of 4.2 mm. Three-wall decompression gave a mean significant reduction of 6.6 mm, and when combined with the advancement of the lateral wall, it reduced proptosis by 12.5 mm.

CONCLUSIONS

We created an experimental model for research and didactic purposes for surgical mangement of Graves' ophthalmopathy. With this model, to obtain 5 mm or more of proptosis reduction, three-wall decompression is required. Advancement of the lateral wall achieved a further reduction in proptosis. For a proptosis reduction of less than 5 mm, decompression of the medial and lateral walls is appropriate.

Role of neck dissection following concurrent chemoradiation for advanced head and neck carcinoma

BACKGROUND

Our primary objective was to determine the role of neck dissection following concomitant chemoradiation (CRT) for advanced stage III-IV head and neck squamous cell carcinoma (HNSCC).

METHODS

One hundred eighty-four patients with HNSCC treated with CRT were included. One hundred twenty-three patients reached a regional complete response (CR) after CRT and no neck dissection was performed. Forty-five patients among the 58 who reached a regional partial response (PR) underwent a neck dissection.

RESULTS

Overall, regional CR rate after CRT was 68%. Patients who reached a regional CR (no neck dissection) had an overall neck recurrence rate of 5%. Patients with regional PR who underwent a neck dissection had a 7% neck recurrence rate.

CONCLUSIONS

Patients with regional CR not followed by a neck dissection have a low rate of neck recurrence. Systematic neck dissection is not mandatory for patients with nodes less than 6 cm reaching a regional CR. For patients with nodes larger than 6 cm, no firm recommendation can be given because of the small number of patients in this series. If the regional response is incomplete, cervical dissection is warranted.

Short polyglutamine tracts in the androgen receptor are protective against breast cancer in the general population

We studied the association of breast cancer with the polymorphic polyglutamine repeat of the androgen receptor (AR) in 255 incident cases of breast cancer and 461 matched controls from the Quebec City metropolitan area. Women for whom the sum of both of the AR (CAG)n-repeats alleles is 39 or less (short-allele AR genotypes) have one-half the risk of breast cancer compared with women for whom the sum of AR (CAG)n-repeats is 40 or more [odds ratio (OR), 0.5; 95% confidence interval (CI), 0.3-0.83; P = 0.007]. This association is stronger in postmenopausal women (180 cases, 297 controls; OR, 0.36; 95% CI, 0.19-0.7; P = 0.003). We also observed an interaction between the type of menopause (natural versus surgical) and the AR genotype on breast cancer risk. Alternately, when subjects were grouped according to their (CAG)n-repeat genotype [homozygous for short alleles (CAG)n < or = 20; other genotypes ("long allele")], results were similar (OR. 0.5; 95% CI, 0.27-0.82; P = 0.007). Thus, women with short-alleles AR genotypes appear to be protected against breast cancer. Short-alleles AR genotypes were observed in 16% of the general population as represented by the control group. Short polyglutamine repeats in the AR protein have been reported to be associated with an increase in the capacity of the receptor to activate transcription of reporter genes in vitro. Furthermore, androgens have been previously shown to inhibit in vitro the growth of breast cancer cell lines. This suggests that differences in the number of polyglutamines in the AR protein may influence individual risk of breast cancer, especially in postmenopausal women, and that this apparent protection could be the consequence of an increased response/sensitivity to androgens.

A prospective longitudinal study of platelet angiotensin II receptors for the prediction of preeclampsia

OBJECTIVES

We developed a simplified method using a relatively small volume of blood for the determination of platelet angiotensin II receptors by saturation analysis and we evaluated its performance for the prediction of preeclampsia.

DESIGN AND METHODS

A platelet suspension with minimal contamination by leukocytes and erythrocytes is obtained by centrifugation and washing. The platelet concentrate is incubated in a multi-well plate with increasing concentration of radiolabelled angiotensin II in the presence or absence of an excess of unlabelled angiotensin II. Bound and free fractions are separated using an oil mixture. Maximum binding is determined by Scatchard plot. This method was compared with a previously reported method. Our method was prospectively evaluated in 801 women attending our institution for routine prenatal care. A specimen was obtained at each trimester of pregnancy whenever possible. Diagnosis of preeclampsia was done postnatally by an experienced obstetrician.

RESULTS

The method showed acceptable correlation with a previously published method although a proportional bias of 2.1 was observed between the two methods. No differences in mean maximum binding were observed between normal and affected pregnancies at either trimester. Even when the results were analyzed longitudinally, using the change in maximum binding between two trimesters for each patient, no significant increase could be documented in preeclamptic pregnancies.

CONCLUSIONS

Platelet angiotensin II receptor measurement is not a clinically useful marker for the prediction of preeclampsia.