title: The changing characteristics and molecular profiles of papillary thyroid carcinoma over time: a systematic review.
abstract: BACKGROUND
  The genetic alterations of papillary thyroid carcinoma (PTC) have been reported to change over the past few decades. We performed this systematic review to further examine the trends and modifications of patient demographic, clinicopathological features and molecular profiles of PTC over time.
  
  
  METHODS
  A literature search was performed within six electronic databases to identify relevant articles. The inclusion criteria were published studies investigating BRAF mutations, RET/PTC rearrangements or RAS mutations in PTCs or classical PTCs. Two teams of reviewers independently screened titles and abstracts of all articles. Full texts of potential articles were read and extracted data were listed and stratified into an excel file according to country, city, institution, and surgical time period. Student t test and Pearson Chi-square were used to analyze the trends of demographic and clinicopathological features of PTC patients and the prevalence of each genetic alteration in individual institutions.
  
  
  RESULTS
  From 3139 articles, we included 16 articles for final analysis. Our results showed an increasing trend of BRAF and a decreasing trend of RET/PTC prevalence over time in PTCs and classical PTCs, accompanied by an older age of PTC patients, an increase in proportion of PTMC and less aggressive behaviours of tumours.
  
  
  CONCLUSIONS
  The demographic and clinicopathological characteristics and molecular profile of PTCs have been changing over the past few decades. These modifications suggest changes in etiologies and risk factors of thyroid cancer that influence the tumorigenesis of PTCs.
authors: Department of Pathology, University of Yamanashi, Yamanashi, Japan.|Department of Pathology, Cho Ray Hospital, Ho Chi Minh City, Vietnam.
authors: Huy Gia
authors: HG
authors: Vuong
authors: Faculty of Medicine, University of Jordan, Amman, Jordan.
authors: Ahmed M A
authors: AM
authors: Altibi
authors: Faculty of Medicine, Menoufia University, Shebin El-Kom, Menoufia, Egypt.
authors: Amr Hesham
authors: AH
authors: Abdelhamid
authors: Pham Ngoc Thach University of Medicine, Ho Chi Minh City, Vietnam.
authors: Phuong Uyen Duong
authors: PU
authors: Ngoc
authors: University of Medicine and Pharmacy, Ho Chi Minh City, Vietnam.
authors: Vo Duy
authors: VD
authors: Quan
authors: Faculty of Medicine, Zagazig University, Zagazig, Egypt.
authors: Mohamed Yousef
authors: MY
authors: Tantawi
authors: Faculty of Medicine, Alexandria University, Alexandria, Egypt.
authors: Mohamed
authors: M
authors: Elfil
authors: University of California, Los Angeles, CA, USA.
authors: Tran Le Huy
authors: TL
authors: Vu
authors: Faculty of Medicine, Al-Azhar University, Cairo, Egypt.
authors: Ahmed
authors: A
authors: Elgebaly
authors: Department of Pathology, University of Yamanashi, Yamanashi, Japan.
authors: Naoki
authors: N
authors: Oishi
authors: Department of Pathology, University of Yamanashi, Yamanashi, Japan.
authors: Tadao
authors: T
authors: Nakazawa
authors: Department of Immunogenetics, Institute of Tropical Medicine, Leading Graduate School Program, and Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto, Nagasaki, Japan.
authors: Kenji
authors: K
authors: Hirayama
authors: Department of Pathology, University of Yamanashi, Yamanashi, Japan.
authors: Ryohei
authors: R
authors: Katoh
authors: Department of Clinical Product Development, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan.
authors: Nguyen Tien
authors: NT
authors: Huy
authors: Department of Pathology, University of Yamanashi, Yamanashi, Japan.
authors: Tetsuo
authors: T
authors: Kondo
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics*; D002291:Carcinoma, Papillary / Q000235:genetics* / Q000473:pathology; D016009:Chi-Square Distribution; D005260:Female; D015321:Gene Rearrangement; D011905:Genes, ras; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D048493:Proto-Oncogene Proteins B-raf / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics; D012307:Risk Factors; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology; D013997:Time Factors; D059467:Transcriptome
chemical_list: D014408:Biomarkers, Tumor; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human; C482119:BRAF protein, human; D048493:Proto-Oncogene Proteins B-raf
keywords: BRAF; RAS; RET/PTC; papillary; thyroid carcinoma