Total surface area is useful for differentiating between aggressive and favorable multifocal papillary thyroid carcinomas

The Impact of Total Tumor Diameter on Lymph Node Metastasis and Tumor Recurrence in Papillary Thyroid Carcinomas

(1) Introduction: The impact of multifocality/bilaterality on the prognosis of papillary thyroid carcinoma (PTC) is a matter of debate. In order to clarify this debate, several studies have attempted to identify additional parameters associated with poor prognosis, including total tumor diameter (TTD), in the context of multifocal PTCs. In this context, this study was carried out to investigate the impact of TTD on tumor recurrence and lymph node metastasis (LNM) in PTCs. (2) Materials and Methods: The sample of this single-center retrospective study consisted of 706 patients diagnosed with PTC. TTD was calculated as the sum of the largest diameters of tumor foci in multifocal tumors. The resulting TTDs were grouped into TTDs ≤ 10 mm, TTDs > 10 mm, TTDs ≤ 20 mm, and TTDs > 20 mm, using 10 mm and 20 mm as cutoff values. (3) Results: There was no significant difference between multifocal papillary microcarcinomas (PTMCs) with a TTD of >10 mm and unifocal PTCs with a primary tumor diameter (PTD) of >10 mm except for advanced age and lymphovascular invasion (LVI). In addition, perineural invasion (PNI) and TTD > 10 mm were found to be significant risk factors for LNM, and PNI, TTD > 10 mm, TTD > 20 mm, and bilaterality were found to be significant risk factors for recurrence. LVI, and TTD > 10 mm were found to be independent significant predictors for recurrence, and LVI and extrathyroidal extension (ETE) were found to be independent significant predictors for LNM. (4) Conclusions: Considering TTD > 10 mm in recurrence risk categorization models and adopting a clinical approach that takes into account multifocal PTMCs with TTD > 10 mm along with unifocal PTCs with PTD > 10 mm may be more useful in terms of clinical management of the disease.

Clinicopathological implications of histological mapping in radical prostatectomy specimens

OBJECTIVE

The present study aims to elucidate the clinicopathological implications of histological mapping in radical prostatectomy specimens.

METHODS

This study included 76 prostatic cancers with histological mapping. The examined characteristics from the histological mappings were the largest tumor dimension, distance from the tumor core to resection margin, tumor dimension from the apex to base, tumor volume, tumor surface area, and proportion of the tumor. In addition, these histological parameters from the histological mapping were compared between patients with positive surgical margin (PSM) and negative surgical margin (NSM).

RESULTS

Patients with PSM were significantly correlated with a higher Gleason score and pT stage than those with NSM. Among the histological characteristics from mappings, there were significant correlations between PSM and the largest tumor dimension, tumor volume, tumor surface area, and proportion of tumor (P < 0.001, P < 0.001, P < 0.001, and P = 0.017, respectively). The distance from the tumor core to the resection margin was significantly longer with PSM than with NSM (P = 0.024). According to the linear regression test, the tumor volume, tumor surface area, and largest tumor dimension were significantly correlated with Gleason score and grade (P = 0.019, P = 0.036, and P = 0.016, respectively). There were no significant differences in the histological factors between the apical and non-apical involved subgroups.

CONCLUSION

Various clinicopathological characteristics assessed from the histological mappings, such as the tumor volume, tumor surface area, and proportion of the tumor, can be useful for interpreting PSM after radical prostatectomy.

Negative Histopathological Prognostic Factors Affecting Morbidity in T1 Differentiated Thyroid Carcinoma

Background: The aim was to evaluate (i) if multifocality is a negative prognostic factor, (ii) the association of diameter of the largest tumor, total tumor diameter, and the ratio of the largest tumor diameter to total tumor diameter (DR) with histopathological and clinical outcome parameters in T1 differentiated thyroid carcinoma (DTC). Methods: In 1014 T1N0/1Mx patients, correlation between multifocality, contralateral lobe involvement, capsular-vascular invasion, diameter of the largest tumor, total tumor diameter, DR, and follow-up results were investigated. Results: Persistent/recurrent disease and necessity for additional radioiodine treatment (RAIT) were more frequent in cases with multifocality and contralateral lobe involvement (p = 0.035, p = 0.015, p = 0.021, and p = 0.04). Persistence/recurrence, reoperation in the neck, and additional RAIT were more frequent in patients with the size of the largest tumor focus >1 cm (p = 0.024, p < 0.001, and p = 0.002) and N1 status (p < 0.001, p < 0.001, and p < 0.001). Mean total tumor diameter was higher in patients with capsular invasion, contralateral lobe, and lymph node involvement (p = 0.001, p = 0.003, and p = 0.013). Conclusion: Multifocality, contralateral lobe involvement, diameter of the largest tumor >1 cm, and N1 status are related with increased risk of disease persistence, recurrence, reoperation, and additional RAIT. Sum of diameter of all tumor foci are associated with capsular invasion.

Extent of Surgery for Low-Risk Differentiated Thyroid Cancer

Although the incidence of thyroid cancer is increasing, survival remains unchanged. Due to concern for overtreatment, surgical management of thyroid cancer has evolved. Papillary thyroid microcarcinoma measuring 1 cm or smaller are considered very low risk and can be managed with either thyroid lobectomy or active surveillance. Total thyroidectomy is no longer recommended for these cancers unless there is evidence of metastasis, local invasion, or aggressive disease. Recommendations for low-risk differentiated thyroid cancer measuring 1 cm to 4 cm remain controversial. This article explores the controversies over the extent of surgery for patients with very low-risk and low-risk differentiated thyroid cancer.

Predictive Factors of Recurrence for Multifocal Papillary Thyroid Microcarcinoma With Brafv600e Mutation: A Single Center Study of 1,207 Chinese Patients

Background: The American Thyroid Association (ATA) guidelines risk stratify Braf^v600e mutated multifocal papillary thyroid microcarcinoma (BMPTMC) into different recurrence risk groups by the extent of extrathyroidal extension (ETE). These findings and modifications for BMPTMC need to be verified in additional studies. Methods: A retrospective cohort study was conducted in BMPTMC patients who underwent total thyroidectomy (TT) and central lymph node dissection (CLND) from 2008 to 2013. Overall, 1,207 patients were included, and predictive factors were identified by univariate and multivariate analysis over a mean 7.5-year follow up. Results: BMPTMC with ETE to capsule shows the same recurrence rate (3.8%) with intrathyroidal BMPTMC. Moreover, BMPTMC with ETE only to strap muscle, which belongs to high-risk group according to ATA guideline, shows relatively lower recurrence rate (13.3%) compared with some intermediate risk categories such as cN1 and >5 pN1. Multivariate analysis using a Cox proportional hazards regression model shows that total tumor diameter (TTD) is associated with significantly higher recurrence for BMPTMC with or without other risk factors (Hazard Ratio (HRO) = 9.86 [95%CI 5.35-18.20], p = 0.00; HRO = 2.32 [95%CI 1.12-4.85], p = 0.02; respectively), while Hashimoto thyroiditis (HT) is found to be protective against the recurrence (HRO = 0.51 [95%CI 0.33-0.79], p = 0.00; HRO = 0.47 [95%CI 0.25-0.89], p = 0.02; respectively). Conclusions: Taken together, capsular ETE and gross ETE to the strap muscles did not have the expected significant influence on recurrence for Chinese BMPTMC patients who underwent TT and CLND. Rather than the extent of ETE, TTD and the lack of HT were identified as predictors for recurrence among BMPTMC with or without other risk factors (vascular invasion, cN1, pN1>5, pN1>3 cm).

SHOULD MULTIFOCAL PAPILLARY THYROID CARCINOMAS CLASSIFIED AS T1A WITH A TUMOR DIAMETER SUM OF 1 TO 2 CENTIMETERS BE RECLASSIFIED AS T1B?

OBJECTIVE

Considering the diameter of the largest tumor while determining T stage in multifocal papillary thyroid microcarcinomas (PTMCs) might cause underestimation of tumoral stage. We aimed to investigate the effect of total tumor diameter (TTD) on tumor node metastasis (TNM) classification in multifocal T1a PTMCs.

METHODS

T1 tumors were grouped as T1a or T1b according to 7th TNM edition. For patients with multifocal T1a, TTD (the sum of the maximal diameter of each focus) was calculated, and these patients were further subgrouped as TTD ≤1 cm or TTD 1 to 2 cm.

RESULTS

There were 724 patients with T1 tumors. Multifocality was observed in 150 (28.5%) of 527 patients with T1a and 84 (42.6%) of 197 patients with T1b tumors (P<.001). Lymph node metastasis (LNM), thyroid capsule invasion, and lymphovascular invasion were significantly higher in T1b compared to T1a (P<.001, P<.001, and P = .015, respectively). There were 8 (1.5%) patients with persistence but not any with recurrence in the T1a group. Persistence and recurrence were observed in 3 (1.5%) and 5 (2.5%) patients in the T1b group, respectively. Among 150 T1a patients with multifocal tumors, TTD was ≤1 cm in 89 (59.3%) and 1 to 2 cm in 61 (40.7%) patients. Number of tumor foci, LNM, and thyroid capsule invasion were significantly higher in multifocal T1a patients with TTD 1 to 2 cm compared to with TTD ≤1 cm (P<.001, P = .032, P = .014, respectively).

CONCLUSION

TTD might be used as a parameter to determine patients at higher risk for persistence, and T1a multifocal PTMCs with TTD 1 to 2 cm can be reclassified as T1b.

ABBREVIATIONS

ETE = extrathyroidal extension LNM = lymph node metastasis PTC = papillary thyroid carcinoma PTMC = papillary thyroid microcarcinoma RAI = radioactive iodine TNM = tumor, node, metastasis TTD = total tumor diameter.

Can ratio of the biggest tumor diameter to total tumor diameter be a new parameter in the differential diagnosis of agressive and favorable multifocal papillary thyroid microcarcinoma?

OBJECTIVES

In this study, we aimed to evaluate the usefulness of a new parameter -ratio of the biggest tumor diameter to total tumor diameter- for the differentiation of agressive and favorable papillary thyroid microcarcinomas (PTMC).

MATERIALS AND METHODS

The diameter of the biggest tumor focus was taken as the primary tumor diameter. Total tumor diameter was calculated as the sum of the maximal diameter of each lesion. Ratio of primary tumor diameter to total tumor diameter was defined as tumor diameter ratio (TDR). Positive and negative predictive value, sensitivity and specificity of TDR to predict capsular invasion, extrathyroidal extension (ETE) and lymph node metastasis (LNM) were determined.

RESULTS

Mean TDR was significantly lower in multifocal PTMC patients with capsular invasion, ETE, lymphovascular invasion and LNM compared to patients without these features. The sensitivities of TDR for the detection of LNM, ETE and capsular invasion were 100%, 100% and 94.2%, respectively. Specificity of TDR was 86.2% for LNM, 88% for ETE and 94.7% for capsular invasion. Best cut off values of TDR that can predict capsular invasion, ETE and LNM in multifocal PTMC were 0.62, 0.57 and 0.56, respectively. Multifocal papillary thyroid carcinoma patients with capsular invasion, ETE and LNM had significantly lower mean TDR when compared to ones without these features.

CONCLUSION

Decreased TDR was associated with capsular invasion, ETE and LNM in patients with multifocal PTMC and PTC. This new parameter might be particularly helpful for the detection of aggressive behavior in multifocal PTMCs.

Association of multifocality, tumor number, and total tumor diameter with clinicopathological features in papillary thyroid cancer

Tumor multifocality is not an unusual finding in papillary thyroid carcinoma (PTC), but its clinical significance is controversial. In this study, we aimed to evaluate impact of multifocality, tumor number, and total tumor diameter on clinicopathological features of PTC. Medical records of 912 patients who underwent thyroidectomy and diagnosed with PTC were reviewed retrospectively. Patients were grouped into four according to number of tumoral foci: N1 (1 focus), N2 (2 foci), N3 (3 foci), and N4 (≥4 foci). The diameter of the largest tumor was considered the primary tumor diameter (PTD), and total tumor diameter (TTD) was calculated as the sum of the maximal diameter of each lesion in multicentric tumors. Patients were further classified into subgroups according to PTD and TTD. Multifocal PTC was found in 308 (33.8 %) patients. Capsular invasion, extrathyroidal extension, and lymph node metastasis were significantly higher in patients with multifocal tumors compared to patients with unifocal PTC. As the number of tumor increased, extrathyroidal extension and lymph node metastasis also increased (p = 0.034 and p = 0.004, respectively). The risk of lymph node metastasis was 2.287 (OR = 2.287, p = 0.036) times higher in N3 and 3.449 (OR = 3.449, p = 0.001) times higher in N4 compared to N1. Capsular invasion, extrathyroidal extension, and lymph node metastasis were significantly higher in multifocal patients with PTD ≤10 mm and TTD >10 mm than unifocal patients with tumor diameter ≤10 mm (p < 0.001, p < 0.001 and p = 0.001, respectively). There was no significant difference in terms of these parameters in multifocal patients with PTD ≤10 mm and TTD >10 mm and unifocal patients with tumor diameter >10 mm. In this study, increased tumor number was associated with higher rates of capsular invasion, extrathyroidal extension, and lymph node metastasis. In a patient with multifocal papillary microcarcinoma, TTD >10 mm confers a similar risk of aggressive histopathological behavior with unifocal PTC greater than 10 mm.

Detection of Tumor Multifocality Is Important for Prediction of Tumor Recurrence in Papillary Thyroid Microcarcinoma: A Retrospective Study and Meta-Analysis

Background:

The clinicopathological characteristics and conclusive treatment modality for multifocal papillary thyroid microcarcinoma (mPTMC) have not been fully established.

Methods:

A retrospective study, systematic review, and meta-analysis were conducted to elucidate the clinicopathological significance of mPTMC. We investigated the multiplicity of 383 classical papillary thyroid microcarcinomas (PTMCs) and the clinicopathological significance of incidental mPTMCs. Correlation between tumor recurrence and multifocality in PTMCs was evaluated through a systematic review and meta-analysis.

Results:

Tumor multifocality was identified in 103 of 383 PTMCs (26.9%). On linear regression analysis, primary tumor diameter was significantly correlated with tumor number (R²=0.014, p=.021) and supplemental tumor diameter (R²=0.117, p=.023). Of 103 mPTMCs, 61 (59.2%) were non-incidental, with tumor detected on preoperative ultrasonography, and 42 (40.8%) were diagnosed (incidental mPTMCs) on pathological examination. Lymph node metastasis and higher tumor stage were significantly correlated with tumor multifocality. However, there was no difference in nodal metastasis or tumor stage between incidental and non-incidental mPTMCs. On meta-analysis, tumor multifocality was significantly correlated with tumor recurrence in PTMCs (odds ratio, 2.002; 95% confidence interval, 1.475 to 2.719, p<.001).

Conclusions:

Our results show that tumor multifocality in PTMC, regardless of manner of detection, is significantly correlated with aggressive tumor behavior.