Retrospective Cohort Study
Copyright ©The Author(s) 2025.
World J Clin Cases. Sep 6, 2025; 13(25): 105204
Published online Sep 6, 2025. doi: 10.12998/wjcc.v13.i25.105204
Table 1 Characteristics of 39 poorly differentiated thyroid carcinoma patients, n (%)
    
M0 (n = 18)
M1 (n = 16)
M2 (n = 5)
P value
Age, median (years, IQR)41 (26-59)52 (49-63)58 (51-62)0.042
Age0.060
    < 45 years10 (55.6)3 (18.8)1 (20.0)
    ≥ 45 years8 (44.4)13 (81.2)4 (80.0)
Sex0.045
    Female13 (72.2)7 (43.8)5 (100)
    Male5 (27.8)9 (56.2)0
Tumor size (cm)0.222
    ≤ 23 (16.7)00
    > 2-46 (33.3)6 (37.5)3 (75.0)
    > 49 (50.0)10 (62.5)1 (25.0)
T stage0.536
    T13 (16.7)00
    T24 (22.2)5 (31.2)1 (20.0)
    T35 (27.8)3 (18.8)1 (20.0)
    T46 (33.3)8 (50.0)3 (60.0)
N stage0.323
    N017 (94.4)13 (81.2)5 (100)
    N14 (10.3)3 (18.8)0
Extrathyroidal invasion6 (33.3)8 (50.0)4 (80.0)0.166
Initial metastatic sites
    Lung09 (56.3)3 (60.0)
    Bone03 (18.8)0
    Lung, bone02 (12.5)2 (40.0)
    Lung, brain01 (6.3)0
    Bone, brain01 (6.3)0
Type of thyroid surgery0.041
    Lobectomy or subtotal thyroidectomy04 (25.0)0
    Total thyroidectomy18 (100)12 (75.0)5 (100)
131I therapy11 (61.1)12 (75.0)5 (100)0.217
131I cumulative dose, median (mCi, IQR)75 (15-100)100 (97-162)580 (100-835)0.005
External beam radiation therapy3 (16.7)7 (43.8)3 (60.0)0.099
External beam radiation therapy, median (cGy, IQR)5600 (3950-6200)3720 (1725-5310)5000 (4750-5500)0.634
Targeted therapy03 (18.8)1 (20.0)-
    Lenvatinib01 (6.25)0
    Lenvatinib, sorafenib02 (12.5)0
    Lenvatinib, sorafenib, cabozantinib001 (20.0)
Cancer-specific mortality1 (5.6)10 (62.5)5 (100)0.001
Overall mortality2 (11.1)12 (75.0)5 (100)0.001
Follow-up, median (years, IQR)8.0 (2.4-14.3)2.0 (1.4-5.2)4.2 (2.8-8.1)0.156
Table 2 Risk factors associated with cancer-specific mortality in poorly differentiated thyroid carcinoma patients, n (%)
    
Survival (n = 23)
Mortality (n = 16)
Univariate HR (95%CI)
P value
Multivariate HR (95%CI)1
P value
Age
    < 45 years11 (47.8)3 (18.8)Reference
    ≥ 45 years12 (52.2)13 (81.2)3.47 (0.95–12.6)0.060
Sex
    Female14 (60.9)11 (68.8)Reference
    Male9 (39.1)5 (31.2)1.58 (0.52–4.81)0.416
Tumor size
    ≤ 2 cm3 (13.0)0 Reference
    > 2-4 cm7 (30.4)8 (53.3)
    > 4 cm13 (56.5)7 (46.7)1.39 (0.62–3.12)0.423
T stage
    T1/T28 (34.8)5 (31.2)Reference
    T3/T415 (65.2)11 (68.8)1.31 (0.44–3.85)0.627
N stage
    N023 (100)12 (75.0)ReferenceReference
    N104 (25.0)6.86 (1.82–25.8)0.00410.1 (2.34–43.3)0.002
M stage
    M017 (73.9)1 (37.5)ReferenceReference
    M16 (26.1)10 (62.5)
    M205 (31.2)2.96 (1.53–5.74)0.0012.41 (1.07–5.39)0.033
Extrathyroidal invasion
    No14 (60.9)7 (43.8)Reference
    Yes9 (39.1)9 (56.2)1.64 (0.61–4.43)0.329
Type of thyroid surgery
    Total thyroidectomy21 (91.3)14 (87.5)Reference
    Lobectomy or subtotal thyroidectomy2 (4.3)2 (6.2)3.48 (0.71–17.0)0.124
131I cumulative dose
    < 100 mCi14 (60.9)7 (43.8)Reference
    ≥ 100 mCi9 (39.1)9 (56.2)1.42 (0.52–3.83)0.493
External beam radiation therapy
    No20 (87.0)6 (37.5)ReferenceReference
    Yes3 (13.0)10 (62.5)4.42 (1.50–13.0)0.0073.07 (0.86–11.0)0.084
Table 3 Clinical features of five patients who developed metastatic disease during follow-up
Patient number
Age/Sex
TNM at diagnosis
Type of thyroid surgery
Time from PDTC diagnosis to metastasis (years)
Cumulative dose of RAI before metastasis (mCi)
Positive finding at detection
Sites of metastasis
Time from metastasis to death (years)
Cumulative dose of RAI (mCi)
External beam radiation therapy, dose (cGy)
Targeted therapy
144/FT4N0M0Total thyroidectomy11.90CT    Lung, bone5.99806000
251/FT4N0M0Total thyroidectomy1.7100PET/CT    Lung2.51000Lenvatinib, sorafenib, cabozantinib
358/FT4N0M0Total thyroidectomy0.730RAI scan    Lung2.15805000
462/FT2N0M0Total thyroidectomy4.9160Chest X-ray    Lung, bone3.28354500
577/FT3N0M0Total thyroidectomy0.930Chest X-ray    Lung0.6600
Table 4 Risk factors associated with distant metastasis in poorly differentiated thyroid carcinoma patients, n (%)

M0 (n = 18)
M1 + M2 (n = 21)
Univariate OR (95%CI)
P value
Age
    < 45 years10 (55.6)4 ((19.0)Reference
    ≥ 45 years8 (44.4)17 (81.0)5.31 (1.27–22.2)0.018
Sex
    Female13 (72.2)12 (57.1)Reference
    Male5 (27.8)9 (42.9)1.95 (0.51–7.49)0.328
Tumor size
    ≤ 2 cm3 (16.7)0Reference
    > 2-4 cm6 (33.3)9 (45.0)
    > 4 cm9 (50.0)11 (55.0)1.72 (0.62–4.83)0.301
T stage
    T1/T27 (38.9)6 (28.6)Reference
    T3/T411 (61.1)15 (71.4)1.59 (0.42–6.07)0.496
N stage
    N017 (94.4)18 (85.7)Reference
    N11 (5.6)3 (14.3)2.83 (0.27–29.9)0.370