Predictive Impact of Metastatic Lymph Node Burden on Distant Metastasis Across Papillary Thyroid Cancer Variants.

Background: While numerous factors determine prognosis in papillary thyroid carcinoma (PTC), distant metastasis (M1) represents one of the most dire. Escalating nodal burden and aggressive histology may contribute to higher metastatic risk, but this relationship is poorly defined and challenging to anticipate. We evaluate the predictive impact of these histological features on predicting distant metastases at initial presentation. Methods: Univariate and multivariable logistic regression models of conventional and aggressive thyroid cancer variants (well-differentiated papillary thyroid carcinoma [WDPTC], diffuse sclerosing variant [DSV], tall cell variant [TCV], poorly differentiated thyroid cancer [PDTC], and anaplastic thyroid carcinoma [ATC]) identified via U.S. cancer registry data were constructed to determine associations between M1 status and quantitative nodal burden. Associations between metastatic lymph node (LN) number and M1 disease were modeled using univariate and multivariable logistic regression with interaction terms, as well as a linear continuous probability model. Results: Overall, M1 prevalence at disease presentation was 3.6% (n = 1717). When stratified by subtype, M1 prevalence varied significantly by histology (WDPTC [1.0%], DSV [2.3%], TCV [4.1%], PDTC [17.4%], ATC [38.4%] [p < 0.001]). For WDPTC, M1 prevalence escalated with metastatic LN number (0 LN+ [0.5%], 1-5 LN+ [2.0%], 6-10 LN+ [3.4%], >10 LN+ [5.5%] [p < 0.001]) and LN ratio (p < 0.001). A statistically significant interaction was observed between histology and increasing nodal burden for M1 risk. On multivariable analysis, each successive metastatic LN conferred increased M1 risk for WDPTC (odds ratio [OR] 1.06 [1.05-1.08], p < 0.001) and TCVs (OR 1.04 [1.02-1.07], p < 0.001). In contrast, other aggressive variants had a higher baseline M1 risk, but this did not vary based on the number of positive LN (DSV, OR 1.02 [0.95-1.10], p = 0.52; PDTC, OR 1.00 [0.98-1.02], p = 0.66; ATC, 1.00 [0.98-1.02], p = 0.97). Conclusions: Progressive nodal burden independently escalates the risk of distant metastasis in WDPTC and TCVs of PTC. Conversely, aggressive variants such as PDTC and ATC have substantial M1 risk at baseline and appear to be minimally affected by metastatic nodal burden. Consideration of these factors after surgery may help tailor clinical decision-making for treatment and surveillance. Further studies are warranted to calibrate the ideal management approach for these higher risk patient groups.

Incidental parathyroidectomy in thyroidectomy and central neck dissection.

BACKGROUND: Although higher thyroidectomy volume has been linked with lower complication rates, its association with incidental parathyroidectomy remains less studied. The volume relationship is even less clear for central neck dissection, where individual parathyroid glands are at greater risk. METHODS: Patients undergoing thyroidectomy with or without central neck dissection were evaluated for incidental parathyroidectomy, hypoparathyroidism, and hypocalcemia. Univariate and multivariable analyses were performed using binary logistic regression. RESULTS: Overall, 1,114 thyroidectomies and 396 concurrent central neck dissections were performed across 7 surgeons. Incidental parathyroidectomy occurred in 22.4% of surgeries (range, 16.9%-43.6%), affecting 7.1% of parathyroids at risk (range, 5.8%-14.5%). When stratified by surgeon, lower incidental parathyroidectomy rates were associated with higher thyroidectomy volumes (R2 = 0.77, P = .008) and higher central neck dissection volumes (R2 = 0.93, P < .001). On multivariable analysis, low-volume surgeon (odds ratio 2.94, 95% confidence interval 2.06-4.19, P < .001), extrathyroidal extension (odds ratio 3.13, 95% confidence interval 1.24-7.87, P = .016), prophylactic central neck dissection (odds ratio 2.68, 95% confidence interval 1.65-4.35, P <.001), and therapeutic central neck dissection (odds ratio 4.44, 95% confidence interval 1.98-9.96, P < .001) were the most significant factors associated with incidental parathyroidectomy. In addition, incidental parathyroidectomy was associated with a higher likelihood of temporary hypoparathyroidism (odds ratio 2.79, 95% confidence interval 1.45-5.38, P = .002) and permanent hypoparathyroidism (odds ratio 4.62, 95% confidence interval 1.41-5.96, P = .025), but not permanent hypocalcemia (odds ratio 1.27, 95% confidence interval 0.48-3.35, P = .63). Higher lymph node yield in central neck dissection was not associated with higher incidental parathyroidectomy rates (odds ratio 1.13, 95% confidence interval 0.85-8.81, P = .82). CONCLUSION: Higher surgical volume conferred a lower rate of incidental parathyroidectomy. Nonetheless, greater lymph node yield in central neck dissections did not result in greater parathyroid-related morbidity. Such findings support the value of leveraging surgical volume to both optimize oncologic resection and minimize complication rates.

Incidence and Mortality Risk Spectrum Across Aggressive Variants of Papillary Thyroid Carcinoma.

Importance: While well-differentiated papillary thyroid carcinoma (WDPTC) outcomes have been well characterized, the prognostic implications of more aggressive variants are far less defined. The rarity of these subtypes has led to their consolidation as intermediate risk for what are in fact likely heterogeneous diseases. Objective: To analyze incidence, clinicopathologic characteristics, and outcomes for aggressive variants of papillary thyroid carcinoma (PTC). Design, Setting, and Participants: This cohort study used data from 2000 to 2016 from hospital-based and population-based US cancer registries to analyze aggressive PTC variants, including diffuse sclerosing (DSV), tall-cell (TCV), insular, and poorly differentiated (PDTC) subtypes. These variants were compared against WDPTC and anaplastic cases. Data analysis was conducted from January 2019 to October 2019. Main Outcomes and Measures: Age-adjusted incidence was calculated via annual percentage change (APC) using the weighted least-squares method. Overall survival and disease-specific survival were analyzed via Cox regression. Propensity-score matching was used to adjust survival analyses for clinical and demographic covariates. Results: Collectively, 5447 aggressive PTC variants were identified (including 415 DSV, 3339 TCV, 362 insular, and 1331 PDTC cases), as well as 35 812 WDPTC and 2249 anaplastic cases. Over the study period, a substantial increase in aggressive variant incidence was observed (APC, 9.1 [95% CI, 7.33-10.89]; P < .001), surpassing the relative increases observed in WDPTC (APC, 5.1 [95% CI, 3.98-6.12]; P < .001) and anaplastic cases (APC, 1.9 [95% CI, 0.75-3.05]; P = .003; parallelism P < .007). Survival varied markedly based on histologic subtype, with a wide spectrum of mortality risk noted; 10-year overall survival was 85.4% (95% CI, 84.6%-86.3%) in WDPTC, 79.2% (95% CI, 73.6%-85.3%) in DSV, 71.9% (95% CI, 68.4%-75.6%) in TCV, 45.1% (95% CI, 40.2%-50.6%) in PDTC, 27.9% (95% CI, 20.0%-38.9%) in the insular variant, and 8.9% (95% CI, 7.5%-10.6%) in anaplastic cases (P < .001). These differences largely persisted even after adjusting for inherent differences in baseline characteristics by multivariable Cox regression and propensity-score matching. Conclusions and Relevance: An upsurge in aggressive PTC incidence was observed at a rate beyond that seen in WDPTC or anaplastic thyroid carcinoma. Moreover, long-term survival outcomes for aggressive PTC subgroups exhibit heterogeneous clinical behavior and a wide range of mortality risk, suggesting that treatment should be tailored to specific histologic subtypes. Given increasing prevalence and disparate outcomes, further investigation to identify optimal therapeutic strategies is needed in these diverse, understudied populations.

Mortality Risk of Nonoperative Papillary Thyroid Carcinoma: A Corollary for Active Surveillance.

Background: Active surveillance is established as an alternative to surgery for papillary thyroid microcarcinomas, but inclusion criteria and mortality risk for pursuing a nonsurgical approach have not been clearly defined. To gauge the feasibility of expanding active surveillance thresholds, we investigated the effects of increasing size and age on disease-specific survival (DSS) in a large nonoperative thyroid cancer cohort, compared against a matched group of surgical patients. Methods: Papillary thyroid carcinoma patients staged T1-4N0M0 were identified in the Surveillance, Epidemiology, and End Results (SEER) database between 1975 and 2015, stratified by nonsurgical and surgical management. Propensity score matching was performed to adjust for imbalances in covariates. Multivariable models were constructed using restricted cubic splines to model nonlinear relationships of age and tumor size with DSS. Results: Overall, 1453 nonoperative patients and 54,718 surgical patients met the inclusion criteria. Collectively, increasing age and size after certain thresholds independently led to greater differences in DSS between nonsurgical and surgical patients. For younger ages (14-55 years), surgical approach compared with nonsurgical approach was not associated with any difference in the 10-year DSS among 0-4 cm cancers (99.8% vs. 100%, p = 0.470), 4.1-6 cm cancers (98.8% vs. 100%, p = 0.599), or >6 cm cancers (97.3% vs. 100%, p = 0.718). Older patients with larger tumors (>75 years, >6 cm) demonstrated the greatest difference in DSS (48.1% vs. 91.3%, p < 0.001). Similar results were found when applying propensity score matching. For age, restricted cubic spline plots showed minimal relative survival hazard in nonoperative cases beginning after age 60 years, with a change point illustrating acceleration in relative hazard beyond age 72 years. For size, relative survival hazard was observed after 2.0 cm and increased slowly with nodule growth up to an inflection point of 4.5 cm. Beyond this, mortality risk escalated with each additional year without plateau. Conclusions: Increasing age and size lead to progressively greater mortality risk without surgery, but only beyond certain thresholds. We define escalating gradients at which a nonsurgical approach may be deemed appropriate, and beyond which survival benefits from surgery become apparent. Such findings reconcile controversial observations regarding age and size in active surveillance and further reshape evolving treatment paradigms in thyroid cancer.

Quantitative survival impact of composite treatment delays in head and neck cancer.

BACKGROUND: Multidisciplinary management of head and neck cancer (HNC) must reconcile increasingly sophisticated subspecialty care with timeliness of care. Prior studies examined the individual effects of delays in diagnosis-to-treatment interval, postoperative interval, and radiation interval but did not consider them collectively. The objective of the current study was to investigate the combined impact of these interwoven intervals on patients with HNC. METHODS: Patients with HNC who underwent curative-intent surgery with radiation were identified in the National Cancer Database between 2004 and 2013. Multivariable models were constructed using restricted cubic splines to determine nonlinear relations with overall survival. RESULTS: Overall, 15,064 patients were evaluated. After adjustment for covariates, only prolonged postoperative interval (P < .001) and radiation interval (P < .001) independently predicted for worse outcomes, whereas the association of diagnosis-to-treatment interval with survival disappeared. By using multivariable restricted cubic spline functions, increasing postoperative interval did not affect mortality until 40 days after surgery, and each day of delay beyond this increased the risk of mortality until 70 days after surgery (hazard ratio, 1.14; 95% confidence interval, 1.01-1.28; P = .029). For radiation interval, mortality escalated continuously with each additional day of delay, plateauing at 55 days (hazard ratio, 1.25; 95% confidence interval, 1.11-1.41; P < .001). Delays beyond these change points were not associated with further survival decrements. CONCLUSIONS: Increasing delays in postoperative and radiation intervals are associated independently with an escalating risk of mortality that plateaus beyond certain thresholds. Delays in initiating therapy, conversely, are eclipsed in importance when appraised in conjunction with the entire treatment course. Such findings may redirect focus to streamlining those intervals that are most sensitive to delays when considering survival burden. Cancer 2018. © 2018 American Cancer Society.

Physician Assistants and Nurse Practitioners in Head and Neck Surgery.

This chapter explores the role of advanced practice clinicians (APCs) and patient care coordinators in the head and neck cancer setting. APCs, which include physician assistants (PAs) and nurse practitioners (NPs), are licensed professional healthcare providers who diagnose and treat illnesses, order and interpret diagnostic tests, and prescribe pharmaceutical and non-pharmaceutical therapies. Although the training, education, and licensure differ between PAs and NPs, their roles are quite similar in head and neck surgery. They collaboratively participate in the medical and surgical management and coordination of head and neck cancer patients in a variety of settings including outpatient clinic, inpatient, and in the surgical suite. APCs can function autonomously in an outpatient clinic with the medical management of postoperative visits and new consults. In an inpatient setting, they perform daily inpatient rounds and manage patient care preoperatively and postoperatively. In head and neck surgery, registered nurses (RNs) usually function in the role of patient care coordinators. They serve as a liaison between the patient and all members of the multidisciplinary team. APCs and patient care coordinators work closely with medical oncologists, radiation oncologists, surgeons, and other allied health professionals to provide high-quality care and achieve optimal patient outcomes in the head and neck cancer setting.

Association of Quantitative Metastatic Lymph Node Burden With Survival in Hypopharyngeal and Laryngeal Cancer.

Importance: Nodal staging for laryngohypopharyngeal cancers is based primarily on size and laterality, with less value placed on absolute number of metastatic lymph nodes (LNs). We are aware of no studies to date that have specifically addressed the prognostic effect of quantitative nodal burden in larynx or hypopharynx malignancies. Objective: To assess the independent impact of quantitative metastatic LN burden on mortality risk. Design, Setting, and Participants: Univariate and multivariable models were constructed to evaluate the association between patients' number of metastatic LNs and their survival, adjusting for factors such as nodal size, laterality, extranodal extension, margin status, and adjuvant treatment. Participants were patients with squamous cell carcinoma of the larynx or hypopharynx undergoing upfront surgical resection for curative intent at a US hospital between 2004 and 2013, as identified in the National Cancer Database. A neck dissection of a minimum of 10 LNs was required. Main Outcomes and Measures: Overall survival. Results: Overall, 8351 cases were included (mean [SD] age, 61 [10.1] years; 6499 men [77.8%]; 4710 patients with metastatic LNs and 3641 with no metastatic LNs). Mortality risk escalated continuously without plateau as number of metastatic nodes increased, with the hazard per node (hazard ratio [HR], 1.19; 95% CI, 1.16-1.23; P < .001) most pronounced up to 5 positive LNs. Extranodal extension was also associated with increased mortality (HR, 1.34; 95% CI, 1.13-1.59; P < .001). Increasing number of nodes examined was associated with improved survival, albeit to a lesser degree (per 10 LNs: HR, 0.97; 95% CI, 0.96-0.98; P < .001) and without a detectable change point. Other nodal factors, including nodal size, contralateral LN involvement (TNM stage N2c), and lower LN involvement (levels 4-5), were not associated with mortality in multivariable models when accounting for number of positive LNs. A novel, parsimonious nodal staging system derived by recursive partitioning analysis exhibited greater concordance with survival than the TNM staging system outlined in the American Joint Committee on Cancer's AJCC Staging Manual, 8th edition. Conclusions and Relevance: The number of metastatic nodes is a predominant independent factor associated with mortality in hypopharyngeal and laryngeal cancers. Moreover, standard nodal staging factors like LN size and contralaterality have no independent prognostic value when accounting for positive LN number. Deeper integration of quantitative metastatic nodal disease may simplify staging and better triage the need for adjuvant therapy.