Thyroid cancer overdiagnosis and overtreatment: a cross- sectional study at a thyroid cancer referral center in Ecuador

Abstract

Background In contrast to the rapid increase in thyroid cancer incidence, the mortality has remained low and stable over the last decades. In Ecuador, however, thyroid cancer mortality has increased. The objective of this study is to determine possible drivers of high rates of thyroid cancer mortality, through a cross-sectional analysis of all patients attending a thyroid cancer referral center in Ecuador. Methods From June 2014 to December 2017, a cross-sectional study was conducted at the Hospital de Especialidades Eugenio Espejo, a regional reference public hospital for endocrine neoplasia in adults in Quito, Ecuador. We identified the mechanism of detection, histopathology and treatment modalities from a patient interview and review of clinical records. Results Among 452 patients, 74.8% were young adults and 94.2% (426) were female. 13.7% had a family history of thyroid cancer, and patients’ median tumor size was 2 cm. The incidental finding was 54.2% whereas 45.8% was non-incidental. Thyroid cancer histology reported that 93.3% had papillary thyroid cancer (PTC), 2.7% follicular, 1.5% Hurtle cells, 1.6% medullary, 0.7% poor differentiated, and 0.2% anaplastic carcinoma. The mean MACIS (metastasis, age, completeness, invasion, and size) score was 4.95 (CI 4.15–5.95) with 76.2% of the thyroid cancer patients having MACIS score less than or equal to 6. The very low and low risk of recurrence was 18.1% (79) and 62% (271) respectively. An analysis of 319 patients with non-metastatic thyroid cancer showed that 10.7% (34) of patients had surgical complications. Moreover, around 62.5% (80 from 128 patients with thyroglobulin laboratory results) of TC patients had a stimulated-thyroglobulin value equal or higher than 2 ng/ml. Overall, a poor surgical outcome was present in 35.1% (112) patients. Out of 436 patients with differentiated thyroid carcinoma, 86% (375) received radioactive iodine. Conclusion Thyroid cancer histological characteristics and method of diagnosis are like those described in other reports without any evidence of the high frequency of aggressive thyroid cancer histology. However, we observed evidence of overtreatment and poor surgical outcomes that demand additional studies to understand their association with thyroid cancer mortality in Ecuador.

Inappropriate use of thyroid ultrasound: a systematic review and meta-analysis

“…Patients with thyroid cancer diagnoses have a higher rate of bankruptcy than patients with other malignancies [6] and experience significantly higher rates anxiety and depression [28,29]. Moreover, the majority of patients with cancer, regardless of size and method of diagnosis, are treated with thyroid surgery which can cause clinically significant morbidity associated with alterations in voice due to damage to recurrent and superior laryngeal nerves, hypoparathyroidism, and, rarely, airway obstruction associated with bilateral vocal cord dysfunction, hematoma formation, or infection [5,30,31]. This concern is particularly relevant when the surgery is performed by a low volume surgeon, which describes the majority of surgeons currently conducting these procedures [32].…”

“…In fact, despite increased diagnosis and treatment of thyroid cancer, the mortality rate continues to be extremely low, given the overall indolent nature of most lesions [4]. The high incidence and low mortality have raised concerns about thyroid cancer overdiagnosis [5], or the detection of subclinical cancers never destined to cause harm. Thyroid cancer overdiagnosis exposes people to potential medical and financial side effects of treatment without an equal expectation of benefit, as the cancer is unlikely to advance [6]; patients with thyroid cancer are at higher risk of bankruptcy than patients with other types of cancer or those without cancer [6,7].…”

Discovery and Validation ofRUNX1DNA Methylation in Differentiating Papillary Thyroid Cancer from Benign Nodules

“…Thyroid cancer (TC) is the most common endocrine malignancy [1,2]. Papillary thyroid cancer (PTC) with low malignancy and good prognosis is the most common subtype, accounting for about 85% of all TC cases [3].…”

Clinical Value of Ultrasonography and Serum Markers in Preoperative N Staging of Thyroid Cancer

“…In most countries, the incidence of thyroid cancer (TC) has increased over the last 3 decades [ 1 ]. Due to the presence of abundant cervical lymphatic drainage in the area, patients with TC often have central or lateral cervical lymph node metastasis (LNM) [ 2 , 3 ].…”