Related Experiment Video
Updated: Jul 6, 2025
Spontaneous Murine Model of Anaplastic Thyroid Cancer
Published on: February 3, 2023
Survival Outcomes of Medullary Thyroid Cancer With and Without Amyloid Deposition
Eman Toraih1, Mohammad Hussein2, Allison Anker3
1Division of Endocrine and Oncologic Surgery, Department of Surgery, School of Medicine, Tulane University, New Orleans, Louisiana; Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
Objective:
Amyloid deposition within tumor stroma is a distinctive histologic feature of medullary thyroid cancer (MTC). However, its prognostic significance remains uncertain. We aimed to elucidate the impact of amyloid status on survival outcomes in a large cohort.
Methods:
The Surveillance, Epidemiology, and End Results registry was queried to identify patients diagnosed with MTC from 2000 to 2019. Patients with amyloid-positive (International Classification of Diseases for Oncology, third edition code 8345/3) and amyloid negative (International Classification of Diseases for Oncology, third edition code 8510/3) tumors were analyzed. Overall and disease-specific survival were compared between matched cohorts using Kaplan-Meier and Cox proportional hazards analyses.
Results:
Of the 2526 MTC patients, 511 of which were amyloid-positive and 2015 that were amyloid negative. Amyloid-positive patients displayed lower T stage (T3/4: 28% vs 85%, P < .001) and less extrathyroidal extension (11.3% vs 81.6%, P < .001). No difference in distant metastasis rate was observed between groups (14.5% vs 14.4%, P = .98). However, amyloid-positive patients showed a tendency for distal lymph node metastasis (1.2% vs 0.3%, P = .020). On univariate analysis, amyloid-positive status showed comparable overall survival times (mean 172.2 vs 177.8 months, P = .17), but a trend toward worse cancer-specific survival (hazard ratios [HR] = 1.31, 95% CI = 0.99-1.71, P = .051). After adjusting for covariates, amyloid deposition did not independently predict overall (HR = 1.15, 95% CI = 0.91-1.47, P = .25) or cancer-specific survival (HR = 1.30, 95% CI = 0.96-1.77, P = .09). Initiating therapy later than 1 month following diagnosis was associated with worse overall survival (HR = 1.25, 95% CI = 1.02-1.54, P = .029).
Conclusions:
The presence of amyloid in MTC paradoxically associates with lower T stage yet exhibits a trend toward worse cancer-specific mortality. Amyloid deposition alone does not independently influence prognosis. Delayed treatment adversely impacted overall survival.
