Increase in Thyroid Cancer (TC) Incidence in Cyprus: Overdiagnosis or True Increase of clinically relevant TC?

Date 21 October 2018
Event ESMO 2018 Congress
Session Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Topics Thyroid Cancer
Aetiology, Epidemiology, Screening and Prevention
Presenter Haris Charalambous
Citation Annals of Oncology (2018) 29 (suppl_8): viii645-viii648. 10.1093/annonc/mdy302
Authors H.C. Charalambous1, A. Demetriou2, S. Frangos3, P. Pavlou2
  • 1Oncology, Bank of Cyprus Oncology Centre, 2006 - Nicosia/CY
  • 2Cyprus Cancer Registry, Ministry of Health, 1448 - Nicosia/CY
  • 3Nuclear Medicine, Bank of Cyprus Oncology Centre, 2006 - Nicosia/CY

Abstract

Background

An increase in Thyroid Cancer (TC) incidence has been seen in most countries worldwide. The same has also been reported for Cyprus¹. The most fundamental issue is whether this increase is due to increased investigations (opportunistic screening) and overdiagnosis of small incidental TC or due to a true increase in clinically relevant TC.

Methods

Data collection in the Cyprus Cancer Registry (CyCR) is guided by the MECC Manual of Coding and Staging for Cancer Registration. In this study, we considered only invasive cancer (ICD-O-3 behavior code=3). From 1998 until 2015 there were 2490 thyroid cancer diagnoses recorded in the CyCR, from which 2309 (92.7%) had histology and staging information recorded. We undertook analysis of the staging of recorded cases in the CyCR and calculated APC (Annual Percent Change) to ascertain whether the increase seen is due to small localized cancers (suggesting opportunistic screening) or also true for locally advanced / Lymph node positive tumours.

Results

The APC for all patients is 11.1% yearly increase. When analyzing by stage, the APC for regional (i.e. locally advanced) TC was 16.3% higher than for localized disease at 11.9%. There was also a statistically significant increase in metastatic cases, but this needs to be interpreted with caution due to the small number of patients with metastatic disease (data not presented).Table: 1826P

SubgroupJoinpointsAPCLower CI of APCUpper CI of APCSignificance probability at α = 0.05
Total011.19.412.80.000
Local111.910.113.70.000
Regional016.312.520.20.000

Conclusions

Analysis of the Cyprus Cancer Registry data provide evidence of a large increase in TC in Cyprus, being due to an increase of both localized and also locally advanced tumours. It is therefore likely that the increase in TC is not only due to opportunistic screening, but also due to a true increase of larger, clinically relevant tumours.

Clinical trial identification

Legal entity responsible for the study

Haris Charalambous.

Funding

Has not received any funding.

Editorial Acknowledgement

Disclosure

All authors have declared no conflicts of interest.