Endocrine Abstracts

Objectives: Anaplastic thyroid carcinoma (ATC) is one of the malignancies with the highest mortality among all cancers. Immune cells are highly abundant in ATC tumors and increased infiltration with tumor-associated macrophages is associated with decreased survival. We hypothesize that systemic inflammatory markers are also associated with survival in patients with ATC and are more elevated in ATC compared to poorly differentiated thyroid carcinoma (PDTC).

Methods: Clinical and biochemical data were retrospectively collected from patients with ATC or PDTC that were treated at our hospital between 1999 and February 2023. Patients with inflammatory or infectious comorbidities were excluded. Inflammatory markers at diagnosis were compared between ATC and PDTC patients and survival was compared between patients with and without systemic inflammation.

Results: Seventy-two ATC patients and 26 PDTC patients were included. As expected, median survival in PDTC patients was significantly longer than in ATC patients (51 [95%-CI: 12-89] months vs 3 [1-5] months respectively). C-reactive protein (CRP, mean concentrations 50.4 vs 6.9 mg/l, P<0.001), erythrocyte sedimentation rate (ESR, 47.5 vs 21.7 mm/hour, P=0.007), absolute white blood cell count (WBC, 13.7 vs 8.0 x10⁹/l, P<0.001) and the percentage of patients with distant metastases at diagnosis (56.3% vs 40.7%, P < 0.001) were all significantly higher in ATC patients when compared to PDTC patients. Albumin concentrations, neutrophil-to-lymphocyte ratio (NLR) and age at diagnosis were not significantly different between both patient groups. Within ATC patients, CRP concentrations (r= -0.558, P<001), WBC (r= -0.405, P=0.001), distant metastases (r= -0.326, P=0.006) and NLR (r= -0.394, P=0.006) at diagnosis were significantly correlated with survival, while sex, albumin and ESR were not. Within ATC patients, the subgroup of patients with elevated CRP at diagnosis had a significantly longer survival than patients without elevated CRP (median survival 1 [0-2] and 10 [0-23] months respectively, P=0.009). The same was true for ATC patients with and without leukocytosis at diagnosis (median survival 1 [0-2] and 5 [0-14] months respectively, P=0.004). On the contrary, median survival of ATC subgroups with and without elevated ESR were not significantly different. In a Cox regression model with the variables CRP concentration, WBC and distant metastases at diagnosis, both CRP concentration and distant metastases at diagnosis were significantly correlated to survival.

Conclusion: Systemic inflammation is more prevalent in ATC when compared to PDTC. Elevated CRP and leukocytosis at diagnosis are prognostic markers in ATC patients.