The relationship of comorbidities to mortality and cause of death in patients with differentiated thyroid carcinoma

Abstract

Understanding how comorbidities contribute to death in cancer patients is becoming an important topic. The present study assessed the role of comorbidities in overall mortality and causes of death in patients with differentiated thyroid carcinoma (DTC). This retrospective cohort study included 2070 patients who underwent thyroidectomy for DTC at a single institution between 2002 and 2005. Probabilities of overall, DTC-specific and other-cause death were examined according to the number of comorbidities, with consideration for competing events. The estimated 15-year cumulative incidences of overall, DTC-specific, and other-cause death were 7.3%, 1.6%, and 5.7%, respectively. Taking the group without comorbidities as a reference, we found that the group with 1–2 comorbidities and the group with ≥3 comorbidities had higher probabilities of other-cause death (subhazard ratios = 2.48 and 9.41, respectively; p < 0.01) and consequently shorter overall survival (hazard ratio = 1.95 and 5.33, respectively; p < 0.01), with adjustment for age, sex, and tumor-node-metastasis classification. In contrast, the probability of DTC-specific death was reduced in patients with ≥3 comorbidities (subhazard ratio = 6.81e-10, p < 0.01). For overall death, the relative proportion of death from DTC reduced when the number of comorbidities increased, and DTC-specific death was not observed in patients with ≥3 comorbidities. Our results show that death from DTC itself accounted for only a fraction of the overall deaths among patients who underwent surgery for DTC. Comorbidities increased overall mortality by increasing the probability of other-cause death. Patients with multiple comorbidities had a low probability of dying from DTC because they died earlier from comorbidities.

Thyroid Nodule Evaluation and Management in Older Adults: A Review of Practical Considerations for Clinical Endocrinologists

“…Although this topic has been studied in other cancer types, it remains underexplored in older adults with thyroid cancer. 82 This study showed that a higher number of comorbidities was associated with a higher probability of death from other causes and a lower probability of death from thyroid cancer. 82 In another single institution study of patients aged ≥70 years with thyroid nodules (N=1,129), 14% had coronary artery disease and 25% had a non-thyroidal malignancy (25%), and the presence of these comorbidities was associated with increased overall mortality.…”

“…82 This study showed that a higher number of comorbidities was associated with a higher probability of death from other causes and a lower probability of death from thyroid cancer. 82 In another single institution study of patients aged ≥70 years with thyroid nodules (N=1,129), 14% had coronary artery disease and 25% had a non-thyroidal malignancy (25%), and the presence of these comorbidities was associated with increased overall mortality. 11 If life expectancy is limited due to comorbidities, then harms associated with treatments should be balanced with the prospect of improved survival.…”

“…[79][80][81][82] Attempting to incorporate competing risks of death in the management of thyroid cancer, Yang et al used data from 29,225 patients with thyroid cancer (tumor size ≤2 cm) from SEER 83. The authors developed a nomogram based on a competing risks model to predict the probability of death for thyroid cancer patients.…”

The Association Between Lymph Node Stage and Clinical Prognosis in Thyroid Cancer

“…Although previous studies have shown that TC patients have favorable survival outcomes, with a mortality rate of ∼10% and a propensity to have lymph node metastases (11,12), certain lymph node involvement was reported to have an adverse impact on the prognosis for TC (13). Moreover, the prognosis for NX patients and the association between N stage and distant metastasis remain unknown.…”

Health-related quality of life analysis in differentiated thyroid carcinoma patients after thyroidectomy

“…Thyroidectomy is still the most commonly performed surgery for any type of thyroid carcinoma 20 . Surgical resection, radioactive iodine therapy, and long-term L-thyroxine replacement therapy can cause various problems in the daily life and psychological state of DTC patients 9 . Although DTC patients have low mortality rates, patients must undergo substantial lifelong surveillance for DTC recurrence 21 .…”