Real-World Outcomes of Differentiated Thyroid Cancer in Oman: A Decade after ATA Guidelines

Abstract

Objectives

The aim of the study was to evaluate the application of the 2015 American Thyroid Association (ATA) guidelines for differentiated thyroid cancer (DTC) management in Oman and to identify predictors of excellent treatment response.

Materials and Methods

This retrospective cohort study included DTC patients followed at Suhar Hospital, Oman, between January 2018 and June 2024. Data on demographics, histopathology, treatment modalities, and follow-up outcomes were extracted from electronic health records. Patients were stratified into low, intermediate, and high risk based on the ATA guidelines, and treatment responses were categorized as excellent, biochemical incomplete, structural incomplete, or indeterminate.

Statistical Analysis

Descriptive statistics summarized baseline characteristics and treatment patterns. Comparative analyses used t-tests for continuous variables and chi-squared tests for categorical variables. Logistic regression models identified predictors of excellent response, with odds ratios (ORs) and 95% confidence intervals (CIs) calculated.

Results

A total of 178 DTC patients were included, with a mean age at diagnosis of 38 years; 87.1% (n = 155) were females. The most common surgery was total thyroidectomy without neck dissection (56.7%, n = 101). The majority of patients (75.3%) were classified as low risk. Radioactive iodine (RAI) therapy was administered to 69.1% of patients, including 61% of low-risk cases. At a median follow-up duration of 48 months (interquartile range [IQR], 24–84; range, 6–204), 61.2% achieved an excellent response, with significant improvement in outcomes over time, including a decrease in positive thyroglobulin antibodies from 15.2 to 5.1% (p = 0.001) and an increase in no evidence of disease on neck ultrasound from 89.2 to 93.8% (p = 0.071). Multivariate analysis identified younger age (OR = 0.97; 95% CI: 0.94–0.99), receipt of RAI (OR = 3.54; 95% CI: 1.56–8.00), and low-risk ATA stratification (OR = 5.15; 95% CI: 1.61–16.53) as significant predictors of excellent response.

Conclusions

This study highlights the frequent use of RAI in low-risk DTC patients in Oman, suggesting potential overtreatment. The identified predictors of excellent response can inform risk-adapted management strategies. Further research is needed to optimize DTC treatment in this population and align practices with international guidelines.

Keywords

differentiated thyroid cancer - American Thyroid Association guidelines - Oman - outcomes - radioactive iodine - thyroidectomy - risk stratification

Introduction

Differentiated thyroid cancer (DTC), comprising papillary and follicular subtypes, is the most common endocrine malignancy worldwide. Its rising incidence has been attributed to the increased diagnostic sensitivity and potential environmental factors.[1] Although most patients experience excellent long-term survival, management should be individualized to avoid overtreatment and minimize morbidity.[2] The 2015 American Thyroid Association (ATA) guidelines introduced a risk-adapted approach, advocating selective use of radioactive iodine (RAI), more conservative surgery in low-risk patients, and dynamic risk stratification during follow-up.[3] These recommendations have reshaped global treatment paradigms, yet their adoption and outcomes vary across health care systems and regions.[4]

In Oman, thyroid cancer is among the most commonly diagnosed malignancies in women. The National Cancer Registry reported 1,285 primary thyroid cancers between 1996 and 2015, with age-standardized incidence rates of 7.6 per 100,000 in females and 2.0 in males.[5] Despite this burden, granular data on long-term outcomes, treatment patterns, and adherence to ATA guidelines remain limited. A prior study at the National Diabetes and Endocrine Center reviewed 346 DTC cases diagnosed between January 2006 and May 2016; 82.7% were disease free at the last follow-up, and lymph node involvement, extrathyroidal extension (ETE), and angiovascular invasion emerged as key prognostic indicators to tailor therapy and surveillance.[6] Building on that foundation, we retrospectively analyzed DTC cases managed at Suhar Hospital's endocrine clinic from January 2018 to June 2024 to (1) describe real-world treatment patterns and outcomes and (2) identify predictors of an excellent response, with the goal of informing local practice and regional protocols.

Materials and Methods

Study Design and Setting

We conducted a retrospective cohort study at the endocrine clinic of Suhar Hospital, Oman, including patients with DTC who were followed between January 2018 and June 2024.

Data Source and Study Population

Data were extracted from the Ministry of Health's national electronic health record system, capturing demographics, clinical characteristics, histopathology, treatments, and outcomes. Eligible patients had a confirmed diagnosis of DTC and received follow-up care at the clinic during the study period. Non-Omani patients and patients with medullary or anaplastic thyroid cancer were excluded. Cases with incomplete clinical or follow-up data were also excluded. [Fig. 1] depicts the case selection flow diagram.

Fig. 1 A flow diagram showing the patient selection and exclusion criteria.

Variables

We collected the following details:

• Demographic data: Age at diagnosis and sex.

• Histopathology: Tumor subtype, size, multifocality, incidental microcarcinomas (foci discovered incidentally after surgery), ETE, lymph node involvement, and vascular invasion.

• Treatment data: Extent of surgery (lobectomy; total thyroidectomy ± neck dissection), RAI therapy (number of doses, cumulative dose), and post-RAI whole-body scan (WBS) findings.

• Follow-up: Thyroglobulin (Tg) was measured by electrochemiluminescence immunoassay (Roche Cobas e601; functional sensitivity of ∼0.04 ng/mL). Thyroglobulin antibody (TgAb) was measured by chemiluminescent immunoassay (Siemens; laboratory reference < 60 IU/mL negative), neck ultrasound findings, ATA response to treatment category, and duration of follow-up. Thyroid stimulating hormone at the last follow-up was available for all patients, but it was not a prespecified outcome, so it was not analyzed.

Risk stratification and response assessment: Patients were stratified as low, intermediate, or high risk according to the ATA DTC risk stratification system.[3] Treatment response was categorized as excellent, biochemical incomplete, structural incomplete, or indeterminate per the ATA criteria.[3]

Statistical Analysis

Analyses were performed in SPSS v23.0 (IBM, Armonk, NY). Continuous variables are summarized as mean ± standard deviation (SD) or median (interquartile range), as appropriate, while categorical variables are summarized as frequencies and percentages. Between-group comparisons used the t-test or Mann–Whitney U test for continuous variables and the chi-squared or Fisher's exact test for categorical variables. Multivariable logistic regression identified predictors of an excellent response, reported as odds ratios (ORs) with 95% confidence intervals (CIs). Two-sided p < 0.05 was considered statistically significant. Complete case analysis was used; percentages and denominators are based on nonmissing data only.

Results

Baseline Clinical and Histopathological Characteristics

Among 178 patients with DTC, the mean age at diagnosis was 38.0 ± 12.0 years; 87.1% (n = 155) were females and 12.9% (n = 23) were males. The most common primary surgery was total thyroidectomy without lymph node dissection (56.7%, n = 101). Other procedures included lobectomy (2.8%, n = 5), lobectomy followed by completion thyroidectomy (18.5%, n = 33), total thyroidectomy with lymph node dissection (16.3%, n = 29), and staged neck dissection after initial total thyroidectomy (5.6%, n = 10). Indications for surgery were solitary thyroid nodule (48.3%, n = 86), multinodular goiter (36.5%, n = 65), and thyrotoxicosis (15.2%, n = 27). Incidental differentiated thyroid carcinoma was present in 50% (n = 89) of cases. Tumors were unifocal in 64.6% (n = 115) of patients and multifocal in 35.4% (n = 63) of patients. The predominant histopathology was classic papillary thyroid carcinoma (PTC; 72%, n = 128), followed by follicular variant PTC (13.5%, n = 24), follicular thyroid carcinoma (8%, n = 14), and other subtypes (6.7%, n = 12). Lymph node metastases were present in 24.7% (n = 44) of patients, lymphovascular invasion in 21.9% (n = 39) of patients, and ETE in 14.6% (n = 26) of patients ([Table 1]).

Table 1 Baseline clinical, surgical, and pathological characteristics

No. of patients (N = 178)		Frequency
Age at diagnosis (y)	Mean ± SD	38 ± 12
Gender	Male	23 (13%)
	Female	155 (87%)
Thyroid cancer primary surgery	Lobectomy	5 (3%)
	Lobectomy then completion	33 (19%)
	Total thyroidectomy with dissection	29 (16%)
	Total thyroidectomy without dissection	101 (57%)
	Total thyroidectomy without dissection, then dissection	10 (6%)
Surgery indication	Solitary thyroid nodule	86 (48%)
	Multinodular goiter	65 (37%)
	Thyrotoxicosis	27 (15%)
Percentage of incidental thyroid carcinoma	No incidental	89 (50%)
	Unifocal incidental	27 (15%)
	Multifocal incidental	62 (35%)
Subtype of cancer	Papillary carcinoma (classic)	128 (71.9%)
	Papillary carcinoma (follicular variant)	24 (13%)
	Papillary carcinoma (oncocytic)	7 (4%)
	Papillary carcinoma (columnar)	2 (1%)
	Poorly differentiated papillary carcinoma	1 (1%)
	Follicular carcinoma	14 (8%)
	Hürthle cell carcinoma	2 (1%)
Tumor focality	Unifocal	115 (65%)
	Multifocal	63 (35%)
Largest size tumor (mm)	Mean ± SD	19.3 ± 15.4
Lymph nodes (n = 167)	No lymph nodes	123 (74%)
	Metastatic	44 (26%)
Lymphovascular invasion (n = 153)	Present	39 (25%)
	Absent	114 (75%)
Extrathyroidal extension (n = 163)	Present	26 (16%)
	Absent	137 (84%)

Abbreviation: SD, standard deviation.

Postsurgical Therapy

WBS data were available for 108/178 patients (60.7%). Among those with a WBS report (n = 108), cervical remnant uptake was seen in 86 (79.6%) patients, regional nodal uptake in 4 (3.7%) patients, and pulmonary metastases in 6 (5.6%) patients. RAI therapy was administered to 69.1% (n = 123) of patients: 56.7% (n = 101) received one dose, 10.1% (n = 18) two doses, and 1.1% (n = 2) more than two doses. The remaining 30.9% (n = 55) did not receive RAI. By ATA risk category, 75.3% (n = 134) were low risk, 12.9% (n = 23) intermediate risk, and 11.8% (n = 21) high risk ([Table 2]).

Table 2 Postoperative management and radioactive iodine (RAI) administration

Outcome (number of cases)[a]		Frequency
Post-RAI treatment whole-body scan (n = 108)	No remnants	12 (11%)
	Neck avid remnants	86 (80%)
	Local lymph nodes metastasis	4 (4%)
	Lung metastasis	6 (6%)
RAI status (n = 176)	Did not receive	55 (31%)
	Received one dose	101 (58%)
	Received two doses	18 (10%)
	Received more than two doses	2 (1%)
Postoperative TgAb (suppressed state); n = 117	Positive	23 (20%)
	Negative	94 (80%)
ATA risk stratification (n = 178)	Low-risk DTC	134 (75%)
	Intermediate-risk DTC	23 (13%)
	High-risk DTC	21 (12%)

Abbreviations: ATA, American Thyroid Association risk; DTC, differentiated thyroid cancer; TgAb, thyroglobulin antibody.

^a Percentages use nonmissing denominators; totals vary by availability.

Follow-Up Outcome

The median follow-up duration was 48 months (interquartile range [IQR], 24–84; range, 6–204). At the last visit, nonstimulated Tg was less than 0.2 ng/mL in 68.0% (n = 121) patients, 0.2 to 1.0 ng/mL in 14.0% (n = 25) patients, and greater than 1.0 ng/mL in 18.0% (n = 32) patients. TgAbs were positive in 5.1% (n = 9) patients. The neck ultrasound showed no evidence of disease in 93.8% (n = 167) cases. Per the ATA response criteria, 61.2% (n = 109) had an excellent response, 15.7% (n = 28) had a biochemical incomplete response, 5.1% (n = 9) had a structural incomplete response, and 18.0% (n = 32) had an indeterminate response.

Changes over Time

The prevalence of TgAb positivity decreased from 15.2% at baseline to 5.1% at last follow-up (p = 0.001). The proportion of patients with no evidence of disease on cervical ultrasound increased from 89.2 to 93.8% (p = 0.071). Analyses were restricted to patients with measurements at both time points. [Fig. 2] displays paired comparisons between the first and last follow-up.

Fig. 2 A paired bar chart showing the outcome improvement during patients' follow-up (n = 178). anti-Tg, antithyroglobulin; US, ultrasound.

Factors Associated with RAI Therapy

Patients who received RAI were older (40.6 ± 10.2 vs. 36.6 ± 12.4 years; p = 0.039) and had larger tumors (24.0 ± 16.0 vs. 9.2 ± 7.6 mm; p = 0.001). The type of primary surgery was strongly associated with RAI use (p < 0.001): 95% of those undergoing thyroidectomy with lymph node dissection received RAI compared with 64% of those without dissection. RAI use was also associated with lymph node metastasis (98%), lymphovascular invasion (92%), and ETE (96%; all p < 0.010). By ATA risk category, 100% of high-risk patients, 86% of intermediate-risk patients, and 61% of low-risk patients received RAI (p < 0.010; [Table 3]).

Table 3 Factors associated with the receipt of radioactive iodine (RAI)

No. of analyzed cases: 176		RAI		p-value
		Received	Not received
		N (%)	N (%)
Age at diagnosis (y)	Mean ± SD	40.6 ± 10.2	36.6 ± 12.4	0.039
Sex	Male	18 (78%)	5 (22%)	0.291
	Female	103 (67%)	50 (33%)
Primary surgery	Thyroidectomy without dissection	84 (64%)	48 (36%)	0.001
	Thyroidectomy with dissection	37 (95%)	2 (5%)
Surgery indication	MNTG	40 (63%)	24 (38%)	0.003
	Thyrotoxicosis	13 (48%)	14 (52%)
	Solitary thyroid nodule	68 (80%)	17 (20%)
Incidental thyroid carcinoma	No incidental	65 (74%)	23 (26%)	0.143
	Incidental	56 (64%)	32 (36%)
Subtype of cancer	Papillary carcinoma	109 (68%)	51 (32%)	0.572
	Follicular carcinoma	12 (75%)	4 (25%)
Tumor focality	Unifocal	73 (64%)	41 (36%)	0.067
	Multifocal	48 (77%)	14 (23%)
Largest size of tumor (mm)	Mean ± SD	24.0 ± 16.0	9.2 ± 7.6	0.001
Lymph node metastases	Absent	74 (61%)	48 (39%)	0.001
	Present	42 (98%)	1 (2%)
Lymphovascular invasion	Present	36 (92%)	3 (8%)	0.001
	Absent	70 (62%)	43 (38%)
Extrathyroidal extension (ETE)	Present	25 (96%)	1 (4%)	0.002
	Absent	89 (65%)	47 (35%)
ATA risk stratification	Low-risk DTC	81 (61%)	52 (39%)	0.001
	Intermediate-risk DTC	19 (86%)	3 (14%)
	High-risk DTC	21 (100%)	0 (0%)

Abbreviations: ATA, American Thyroid Association; DTC, differentiated thyroid cancer; MNTG, multinodular thyroid goiter; SD, standard deviation; Tg, thyroglobulin.

Outcomes and Predictors of an Excellent Response

Excellent response was more frequent among patients treated with RAI than those managed without RAI (77.1 vs. 45.5%; p = 0.01; [Fig. 3]), particularly among the low-risk subgroup (74.7 vs. 28.4%; p = 0.001). On multivariable logistic regression, younger age (OR = 0.97; 95% CI: 0.94–0.99; p = 0.039), receipt of RAI (OR = 3.54; 95% CI: 1.56–8.00; p = 0.002), and low-risk ATA category (OR = 5.15; 95% CI: 1.61–16.53; p = 0.006) independently predicted an excellent response ([Table 4]).

Table 4 Multivariable predictors of an excellent response

No. of analyzed cases: 178		Outcome		Adjusted odds ratio (OR)
		Excellent response	Incomplete or indeterminate response	p-value	OR (95% CI)
		N (%)	N (%)
Age at diagnosis (y)	Mean ± SD	36.2 ± 10.9	41 ± 13.1	0.039	0.97 (0.94–0.99)
Primary surgery	Thyroidectomy without dissection	91 (68%)	43 (32%)	0.039	2.65 (1.05–6.67)
	Thyroidectomy with dissection	18 (46%)	21 (54%)		1.00
Incidental	No incidental	62 (70%)	27 (30%)	0.022	2.31 (1.13–4.72)
	Incidental	47 (53%)	42 (47%)		1.00
RAI	Did not receive RAI	25 (45%)	30 (55%)	0.002	1.00
	Received RAI	84 (69%)	37 (31%)		3.54 (1.56–8.00)
ATA risk stratification	Low-risk DTC	88 (66%)	46 (34%)	0.006	5.15 (1.61–16.53)
	Intermediate-risk DTC	14 (61%)	9 (39%)	0.038	4.36 (1.09–17.55)
	High-risk DTC	7 (33%)	14 (67%)		1.00
Total		109 (61%)	69 (39%)

Abbreviations: ATA, American Thyroid Association; CI, confidence interval; DTC, differentiated thyroid cancer; N, number; OR, odds ratio; RAI, radioactive iodine; SD, standard deviation; Tg, thyroglobulin.

Note: % represents the proportion of excellent responses by variable categories (raw %).

Fig. 3 Response to treatment outcome in low-risk patients related to radioactive iodine (RAI) treatment.

Discussion

This retrospective cohort of 178 patients with DTC at Suhar Hospital, Oman, examines real-world adoption of the 2015 ATA recommendations nearly a decade after their release. We describe treatment patterns, outcomes, and predictors of excellent response in a Middle Eastern setting, adding to the limited regional literature. The predominance of low-risk disease (75.3%) mirrors global epidemiology in which improved detection has shifted stage at presentation; classic PTC accounted for 72% of tumors in our cohort.[1] [7] Despite risk-adapted guidance, RAI was administered to 69.1% of patients, including 61% of those classified as low risk, indicating potential overuse relative to selective RAI recommendations.[3] Similar utilization patterns have been reported in the United Arab Emirates and Saudi Arabia, underscoring between-center variability in guideline uptake across the Gulf.[8] [9] [10] Observational data suggest RAI receipt in low-risk DTC is strongly influenced by physician practice style rather than tumor biology.[11] Recent guidance also emphasizes active surveillance (AS) for appropriately selected microcarcinomas and shared decision-making.[12] In our context, limited formal AS protocols, constrained longitudinal US/Tg capacity, travel burdens to tertiary centers, and a cultural preference for definitive surgery may suppress AS adoption. Targeted clinician education with audit and feedback, standardized AS pathways with recall systems, and bilingual decision aids could safely reduce reflex RAI use.[11] [12]

At a median follow-up of 48 months (IQR: 24–84), 61.2% achieved an excellent response—lower than the 82.7% disease-free survival reported in an earlier Omani series (2006–2016).[6] This difference likely reflects cohort composition, use of ATA dynamic response categories versus “disease-free” status, and shorter/heterogeneous follow-up. Eighteen percent of patients were classified as indeterminate based on Tg/TgAb; most were ultrasound negative (27/32) and nearly half had not received RAI, suggesting our excellent response rate may be conservative, especially among non-RAI patients, where low-level Tg may represent remnant rather than disease.[13] The 2025 ATA guidance defines an excellent response after total thyroidectomy without RAI as nonstimulated Tg less than 2.5 ng/mL with undetectable TgAb; a sensitivity analysis reclassifying eligible indeterminate cases using this threshold would likely modestly raise the excellent response estimate, but we acknowledge this analytically rather than recalculate here.[12]

Indicators of improvement over time were observed. TgAb positivity declined from 15.2 to 5.1% (p = 0.001), and the proportion with no evidence of disease on cervical ultrasound increased from 89.2 to 93.8% (p = 0.071) in paired analyses, supporting risk-adapted surveillance and dynamic reassessment.[3] RAI receipt was associated with higher excellent response rates (77.1 vs. 45.5%; p = 0.010), particularly within the low-risk subgroup (74.7 vs. 28.4%; p = 0.001). These associations should be interpreted cautiously because of confounding by indication in retrospective data: patients receiving RAI were older and had larger tumors, more lymph node metastases, lymphovascular invasion, and ETE, all factors that influence both treatment and outcome.[14] [15] Prospective data from Iranian and Filipino cohorts similarly question the necessity of RAI in low-risk DTC and favor individualized dosing strategies to limit exposure.[15] [16]

In multivariable analysis, younger age (OR: 0.97; 95% CI: 0.94–0.99), RAI receipt (OR: 3.54; 95% CI: 1.56–8.00), and low-risk ATA stratification (OR: 5.15; 95% CI: 1.61–16.53) independently predicted an excellent response, consistent with reports that refine ATA criteria with additional prognostic factors, including molecular markers and tumor size.[7] [17] [18] Nonincidental presentation was also associated with higher odds of excellent response (OR: 2.31; 95% CI: 1.13–4.72), an observation that invites further study because incidental DTC is often considered biologically indolent. Our data, together with Greek and Saudi analyses, suggest heterogeneity within “incidental” disease and support outcome stratification by ATA risk rather than detection mode alone.[19] [20] [21] Underuse of AS for very low-risk microcarcinomas, endorsed in recent guidance and supported by U.S. surveys, likely represents a missed opportunity in our setting.[22] [23]

Patterns of RAI administration in this cohort, driven by older age, extensive surgery (95% among those undergoing thyroidectomy with dissection), and adverse histopathology (e.g., lymphovascular invasion 92%), are consistent with a risk-based approach, yet raise concerns about overtreatment among low-risk patients. Potential harms of RAI, including salivary gland dysfunction and second primary malignancies, should be weighed against benefits in shared decision-making.[3] [24] Regional data echo our observations: a Dubai series reported low recurrence (5.5%) but high persistence (15.3%) after surgery,[8] and Saudi cohorts highlighted morbidity from lymph node dissection without clear survival advantages in low-risk disease.[9] [13] [25] For the minority with distant metastases (3.3% in our cohort), disease-specific mortality remains a priority, in line with recent Saudi experience advocating intensified therapy in selected cases.[26] [Table 5] compares our findings with regional and local studies.

Table 5 Comparative overview of regional DTC cohorts

Variable	Suhar Hospital (2018–2024), Oman	NDEC (2006–2016), Oman[6]	Tawam Hospital (2008–2018), UAE[10]	KSUMC (2000–2020), Saudi Arabia[20]
Sample size	178 patients	346 patients	762 patients	674 patients
Mean age and sex	38 y; 87% females	38 y; 84% females	39.6 y; 76.5% females	47.2 y; 84.7% females
Most common histology	91% PTC	92% PTC	92% PTC	90% PTC
ATA risk stratification	Low, 75% Intermediate, 13% High, 12%	Low, 61% Intermediate, 36% High, 3%	AJCC stage: 88.6% stage I (ATA not reported)	Low, 60% Intermediate, 19% High, 21%
Primary surgery	Lobectomy, 3% Total thyroidectomy, 97%	Total thyroidectomy, 100%	Lobectomy, 6.2% Total thyroidectomy, 93.8%	Lobectomy, 10.7% Total thyroidectomy, 89.3%
RAI treatment	69% received (including 61% of low-risk patients)	80% received	Overall, 77.4% received RAI; fell to 60% by 2018	46% received
Response to treatment	ER, 61% (predominantly in low-risk cases), IR, 18%; SIR, 5%; BIR, 16%	ER, 83% (92% in low-risk cases)	Not reported	ER, 68% (mostly in low-risk cases); IR, 9.6%; SIR, 9.6%; BIR, 12%
Reported predictors	ER associated with RAI receipt, younger age, and ATA low risk	Disease-free survival associated with LN status, ETE, and lymphovascular invasion	Nationality and LN involvement predicted surgical extent and RAI use	Worse response associated with larger tumor size, lymphovascular invasion, and obesity

Abbreviations: ATA, American Thyroid Association risk category; AJCC, American Joint Committee on Cancer staging; BIR, biochemical incomplete response; ER, excellent response; ETE, extrathyroidal extension; IR, indeterminate response; KSUMC, King Saud University Medical City (Saudi Arabia); LN, lymph node; NDEC, National Diabetes and Endocrine Center (Oman); PTC, papillary thyroid carcinoma; RAI, radioactive iodine; SIR, structural incomplete response; y, year.

This study has limitations. Its single-center, retrospective design may limit generalizability; molecular profiling (e.g., BRAF, RAS) was unavailable; and heterogeneity in follow-up (e.g., variable Tg stimulation) could bias outcomes. Quality-of-life and long-term toxicity measures were not captured, despite their growing relevance in DTC care.[24] Analyses followed a complete-case approach; missing values were excluded from denominators and no imputation was performed, so residual bias from informative missingness cannot be excluded. Future multicenter prospective studies in Oman and the wider Gulf should incorporate patient-reported outcomes, cost-effectiveness, and molecular markers to refine risk stratification and align regional practice with international standards.[27] [28]

Conclusion

Outcomes for DTC managed under the 2015 ATA framework in Oman are favorable, but opportunities remain to reduce RAI use among low-risk patients and expand AS, where appropriate. Younger age, RAI receipt, low-risk status, and nonincidental presentation predicted an excellent response and can inform individualized care. Broader adoption of dynamic risk stratification, structured AS pathways, and shared decision-making may further optimize management. Coordinated multicenter research is needed to guide regional protocols and ensure evidence-based, patient-centered practice.

Conflict of Interest

None declared.

Ethical Approval

The study was approved by the Suhar Hospital institutional review board (IRB Approval no.: MoH/CSR/25/30083). As a retrospective analysis with no direct patient contact, all data were anonymized. The study adhered to the Declaration of Helsinki.

Authors' Contributions

I.A. contributed to study conception, data analysis, and manuscript drafting.

S.A.G. contributed to patient care and manuscript review.

H.A.R. contributed to the statistical analysis and drafting of the results section.

A.A.R. contributed to patient care and manuscript review.

All authors approved the final manuscript.

Data Availability

Data supporting the findings are available from the corresponding author upon reasonable request.

• References

• 1 Lim H, Devesa SS, Sosa JA, Check D, Kitahara CM. Trends in thyroid cancer incidence and mortality in the United States, 1974–2013. JAMA 2017; 317 (13) 1338-1348
• 2 Tuttle RM, Alzahrani AS. Risk stratification in differentiated thyroid cancer: from detection to final follow-up. J Clin Endocrinol Metab 2019; 104 (09) 4087-4100
• 3 Haugen BR, Alexander EK, Bible KC. et al. 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer. Thyroid 2016; 26 (01) 1-133
• 4 Nixon IJ, Wang LY, Palmer FL. et al. The impact of the American Thyroid Association's risk stratification system on treatment recommendations for differentiated thyroid cancer. Thyroid 2017; 27 (04) 484-492
• 5 Al-Lawati JA, Al-Zakwani I, Fadhil I, Al-Bahrani BJ. Cancer incidence in Oman (1996–2015). Oman Med J 2019; 34 (04) 271-273
• 6 Kunjumohamed FP, Al Rawahi A, Al Busaidi NB, Al Musalhi HN. Disease-free survival of patients with differentiated thyroid cancer: a study from a tertiary center in Oman. Oman Med J 2021; 36 (02) e246
• 7 Grani G, Gentili M, Siciliano F. et al. A data-driven approach to refine predictions of differentiated thyroid cancer outcomes: a prospective multicenter study. J Clin Endocrinol Metab 2023; 108 (08) 1921-1928
• 8 Al-Haideri MH, Othman M, Ahmad D, Alshamsi M, Al Janabi M. Incidence of persistence and recurrence of differentiated thyroid cancer in post-surgical cases from a tertiary care hospital in Dubai, United Arab Emirates. Cureus 2024; 16 (07) e63555
• 9 Al-Qahtani KH, Tunio MA, Al Asiri M. et al. Clinicopathological features and treatment outcomes of differentiated thyroid cancer in Saudi children and adults. J Otolaryngol Head Neck Surg 2015; 44: 48
• 10 Azhar M, Aziz F, Almuhairi S. et al. Decline in radioiodine use but not total thyroidectomy in thyroid cancer patients treated in the United Arab Emirates: a retrospective study. Ann Med Surg (Lond) 2021; 64: 102203
• 11 Wallner LP, Banerjee M, Reyes-Gastelum D. et al. Multilevel factors associated with more intensive use of radioactive iodine for low-risk thyroid cancer. J Clin Endocrinol Metab 2021; 106 (06) e2402-e2412
• 12 Ringel MD, Sosa JA, Baloch Z. et al. 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer. Thyroid 2025; 35 (08) 841-985
• 13 Momesso DP, Tuttle RM. Update on the management of differentiated thyroid cancer. Endocrinol Metab Clin North Am 2014; 43 (02) 401-417
• 14 Atallah K, Awny S, Abdelwahab K. et al. Morbidity patterns and long-term outcomes of central lymph node dissection in thyroid cancer patients. Sci Rep 2025; 15 (01) 1-8
• 15 Norouzi G, Shafiei B, Hadaegh F. et al. Comparison of radioiodine ablation rates between low versus high dose, and according to the surgeon's expertise in the low-risk group of differentiated thyroid cancer. World J Nucl Med 2020; 20 (01) 17-22
• 16 Santiago AGG, Isidro MJ, Parra J. Predictors of response to therapy among post-thyroidectomy adult Filipino patients with papillary thyroid carcinoma based on the 2015 American Thyroid Association guidelines. J ASEAN Fed Endocr Soc 2021; 36 (02) 161-166
• 17 Maino F, Botte M, Dalmiglio C. et al. Prognostic factors improving ATA risk system and dynamic risk stratification in low- and intermediate-risk DTC patients. J Clin Endocrinol Metab 2024; 109 (03) 722-729
• 18 Wang H, Li Q, Tian T, Liu B, Tian R. Improving the risk prediction of the 2015 ATA recurrence risk stratification in papillary thyroid cancer. J Clin Endocrinol Metab 2025; 110 (02) 534-541
• 19 Christakis I, Dimas S, Kafetzis ID, Roukounakis N. Risk stratification of 282 differentiated thyroid cancers found incidentally in 1369 total thyroidectomies according to the 2015 ATA guidelines; implications for management and treatment. Ann R Coll Surg Engl 2018; 100 (05) 357-365
• 20 Jammah AA, AlSadhan IM, Alyusuf EY, Alajmi M, Alhamoudi A, Al-Sofiani ME. The American Thyroid Association risk stratification and long-term outcomes of differentiated thyroid cancer: a 20-year follow-up of patients in Saudi Arabia. Front Endocrinol (Lausanne) 2023; 14: 1256232
• 21 Al-Dahash R, Alsohaim A, Almutairi ZN. et al. Risk stratification of differentiated thyroid cancer at King Abdullah Specialized Children's Hospital Endocrinology Clinic in Riyadh, Saudi Arabia. Cureus 2023; 15 (12) e51372
• 22 Pitt SC, Yang N, Saucke MC. et al. Adoption of active surveillance for very low-risk differentiated thyroid cancer in the United States: a national survey. J Clin Endocrinol Metab 2021; 106 (04) e1728-e1737
• 23 Malik AA, Aziz F, Beshyah SA, Aldahmani KM. Characteristics and management of papillary thyroid microcarcinoma in the United Arab Emirates: experience from a large tertiary hospital. Saudi J Med Med Sci 2022; 10 (01) 42-48
• 24 Lubitz CC, Kiernan CM, Toumi A. et al. Patient perspectives on the extent of surgery and radioactive iodine treatment for low-risk differentiated thyroid cancer. Endocr Pract 2021; 27 (05) 383-389
• 25 Radi S, Al-Maghrabi M, Binmahfooz S, Franco M, Payne R, Tamilia M. Characteristics and prognostic markers of aggressive subtypes of thyroid cancer: a retrospective study. Cancer Rep (Hoboken) 2025; 8 (03) e70131
• 26 Howaidi A, Alswailem A, Hakami A. et al. Disease-specific mortality of differentiated thyroid cancer with distant metastases. J Endocr Soc 2025; 9 (04) bvaf034
• 27 Pambinezhuth F, Al Busaidi N, Al Musalhi H. Epidemiology of Thyroid Cancer in Oman. Ann Endocrinol Metab 2017; 1 (01) 11-17
• 28 Alseddeeqi E, Baharoon R, Mohamed R, Ghaith J, Al-Helali A, Ahmed LA. Thyroid malignancy among patients with thyroid nodules in the United Arab Emirates: a five-year retrospective tertiary centre analysis. Thyroid Res 2018; 11 (01) 1-7

Publication History

Article published online:
20 January 2026