Practice patterns in management of differentiated thyroid cancer since the 2014 British Thyroid Association (BTA) guidelines

BACKGROUND

The updated 2014 BTA guidelines emphasised a more conservative, risk adapted model for the management of low-risk differentiated thyroid cancer (DTC). In comparison to historical approach of total thyroidectomy combined with radioactive iodine, treatment de-escalation is increasingly supported.

AIMS

To evaluate the impact of the updated BTA guidelines on the management of DTC cases at regional UK centre.

METHODS

All DTC patients were retrospectively identified from regional thyroid MDT database between Jan2009-Dec2020. Oncological treatment and clinico-pathological characteristics were analysed.

RESULTS

623 DTC cases were identified; 312 (247 female: 65 male) between 2009 and 2014 and 311 (225 female: 86 male) between 2015 and 2020. Median age is 48 years (range 16-85). By comparing pre- and post-2015 cohorts, there was a significant drop in total thyroidectomy (87.1% vs 76.8%, p = 0.001) and the use of radioactive iodine (RAI) (73.1% vs 62.1%, p = 0.003) in our post-2015 cohort. When histological adverse features were analysed, extra-thyroidal extension (4.2% vs 17.0%, p=< 0.001), lymphovascular invasion (31.4% vs 50.5%, p=<0.001) and multi-centricity (26.9% vs 43.4%, p = 0.001) were significantly increased in the post 2015 cohort. Nonetheless, total thyroidectomy (TT) remains the treatment choice for low risk T1/2 N0 M0 disease in 65.3% (124/190) in post-2015 cohort for several reasons. Reasons include adverse histological features (50.8%), benign indications (32.5%), contralateral nodules (11.7%), patient preference (2.5%), and diagnostic uncertainty (2.5%).

CONCLUSION

Our study confirms a move towards a more conservative approach to patients with low-risk DTC in the UK, which is in keeping with the BTA 2014 guideline and international trends, but total thyroidectomy remains prevalent for low risk T1/2 N0 M0 disease for other reasons.

A quantitative assessment of the number of disease foci in papillary thyroid cancer

AIM

Multifocality is a frequent feature of papillary thyroid carcinoma (PTC). Its prognostic value is controversial although national guidelines recommend treatment intensification if present. However, multifocality is not a binary but discrete variable. This study aimed to examine the association between increasing number of foci and risk of recurrence following treatment.

METHODS

577 patients with PTC were identified with median follow-up of 61 months. Number of foci were taken from pathology reports. Log-rank test was used to assess significance. Multivariate analysis was performed and Hazard Ratios were calculated.

RESULTS

Of 577 patients, 206(35%) had multifocal disease and 36(6%) recurred. 133(23%), 89(15%) and 61(11%) had 3+, 4+ or 5+ foci respectively. The 5-year RFS stratified by number of foci was 95%v93% for 2+foci (p = 0.616), 95%v96% for 3+foci (p = 0.198) and 89%v96% for 4+foci (p = 0.022). The presence of 4 foci was associated with an over 2-fold risk of recurrence (HR 2.296, 95% CI 1.106-4.765, p = 0.026) although this was not independent of TNM staging. Of the 206 multifocal patients, 31(5%) had 4+foci as their sole risk factor for treatment intensification.

CONCLUSION

Although multifocality per se does not confer worse outcome in PTC, finding 4+foci is associated with worse outcome and could therefore be appropriate as a cut-off for treatment intensification. In our cohort, 5% of patients had 4+foci as a sole indication for treatment intensification, suggesting that such a cut off could impact clinical management.

Evaluation of Histopathological Risk Model in a Cohort of Oral Squamous Cell Carcinoma Patients Treated with Accompanying Neck Dissection

To investigate the applicability of the validated histological risk model in a cohort of oral cavity squamous cell carcinoma patients treated concurrently with neck dissections. Primary tumours from 85 patients with primary excision of T1 and T2 Oral Squamous Cell Carcinomas (TNM 7th edition) including neck dissection were scored by three pathologists in consensus according to the validated risk model. The risk score data, along with traditional dataset values, were analysed to determine possible association with nodal metastasis and extracapsular spread. Seventy-two patients (54%) were classified with low or intermediate risk and 62 (46%) patients were 'high risk'. A chi squared test showed that cases with nodal metastasis were highly statistically significant with the overall risk model score (X² = 22.62 p = 0.0001). None of the neck dissections from tumours with low risk score showed evidence of metastasis (NPV = 100%) suggesting the risk score may also be a useful tool for predicting an absence of metastasis. Risk assessment of low-stage oral squamous cell carcinoma primary tumours may be predictive of the presence or absence of metastasis at presentation. Knowledge of the risk score and its constituent parts may inform treatment decisions at multidisciplinary meetings. Low risk squamous cell carcinoma may be a rare variant with low metastatic potential and excellent long-term survival.

Population-based p16 and HPV positivity rates in oropharyngeal cancer in Southeast Scotland

We assessed a population-based cohort of patients diagnosed with oropharyngeal squamous cell carcinoma in Southeast Scotland over 13 months. p16 and human papilloma virus (HPV) expression were determined, and correlated with stage, treatment, smoking and alcohol history, and disease outcomes. Retrospective analysis was performed on 60 patients. p16 immunohistochemistry and HPV genotyping were performed on formalin-fixed paraffin-embedded tissues. HPV infection (as defined by p16 positivity and/or HPV PCR positivity) was identified in 57% of samples, while dual positives were detected in 45% of cases. HPV16 was most prevalent of the HPV types and was associated with 90% of positive samples. Cause-specific 1-year and 2-year survivals were 82.5% and 78.2%, respectively. The p16-positive and HPV-positive groups demonstrated significantly increased cause-specific survival in comparison with their negative counterparts.

Uncommon presentation of nasopharyngeal extramedullary plasmacytoma: a case report and literature review

OBJECTIVE

We report an exceptional presentation of extramedullary plasmacytoma of the nasopharynx without bone marrow involvement or other characteristics of multiple myeloma.

METHOD

Case report and a review of the world literature concerning the clinical presentation, histopathological features, optimal treatment and prognosis of nasopharyngeal extramedullary plasmacytoma.

RESULTS

Reports of patients with symptomatic extramedullary plasmacytomas of the nasopharynx eventually being documented with histopathological evidence are not uncommon; however, the converse appears to be an extremely rare event. The patient was completely asymptomatic and following a paroxysm of coughing, expectorated a polypoidal nodule, which on histopathological investigation had features suggestive of extramedullary plasmacytoma.

CONCLUSION

Although these tumours commonly present with significant nasal symptoms, this exceptional presentation in an asymptomatic patient has never been previously reported. Unusual presentations of rare tumours can pose considerable diagnostic dilemmas to both the surgeon and histopathologist. Awareness of these rarities is important to ensure the best patient care.