Table 1. Characteristics of included studies.
| Author / Year of publication / Country | Institution | Surgical Period | No. of cases | Mean of age | Tissue treatment method | Patient selection criteria | Detection method (Manufacturer) |
|---|---|---|---|---|---|---|---|
| Mathur/2011/US [13] | University of California at San Francisco | 1991 – 1995 1996 – 2000 2000 – 2005 |
74 103 51 |
46.4 43.5 48.7 |
Frozen Frozen Frozen |
Consecutive patients underwent initial evaluation and treatment at the institution. Thyroidectomy was performed in all cases. | BRAF, RAS: Direct sequencing (Applied Biosystem) RET/PTC: Nested PCR |
| Jung/2014/US [14] | University of Pittsburgh | 1974 – 1985 1990 – 1992 2000 2009 |
62 22 24 65 |
37.0 a 51.0 a 50.0 a 53.0 a |
FFPE FFPE FFPE FFPE |
Cases were chosen consecutively within each of preselected periods until the numeric target was fulfilled. No selection criteria of cPTCs were described. | BRAF, RAS: Real-time LightCycler PCR and fluorescent melting curve analysis (Roche) RET/PTC: Dual-color interphase FISH |
| Romei/2012/Italy [11] | Endocrine units of Pisa, Perugia and Milan | 1996 – 2000 2001 – 2005 2006 – 2010 |
56 98 106 |
40.9 44.0 47.6 |
Frozen Frozen Frozen |
Cases were neither consecutive nor selected, and the same procedures of collection were followed in the three centers. No selection criteria of cPTCs were described. | BRAF: Direct sequencing (Applied Biosystem) RET/PTC: Southern blotting |
| Nam/2012/Korea [18] | Seoul St. Mary's Hospital | 2008 – 2009 | 355 | 46.9 | FFPE | Thyroid tumor tissues were sampled from patients with PTC who underwent thyroidectomy. No selection criteria of cPTCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Lee/2014/Korea [19] | Seoul St. Mary's Hospital | 2011 – 2012 | 200 | 45.7 | FFPE | The patients with PTC who underwent surgery at the institution during the selected time period were enrolled in this study. No selection criteria of cPTCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Smyth/2005/Ireland [20] | St. James's Hospital | 1982 – 2003 | 18 | 49.6 | FFPE | Samples of PTC accessioned between 1982 – 2003 were analysed. No selection criteria of cPTCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Kowalska/2016/Poland [21] | Holycross Cancer Center | 2000-2004 2005-2009 2010-2013 |
152 195 254 |
52.0 a 53.0 a 54.0 a |
FFPE FFPE FFPE |
Archived tumor tissue was retrieved from 785 unselected PTCs diagnosed between 2000-2013. No selection criteria of PTCs were described. | BRAF: Direct sequencing (Applied Biosystem), Allele-specific PCR and quantitative real time PCR (Qiagen) |
| Nakazawa/2009/Japan [22] | University of Yamanashi | 2001 – 2006 | 14 | 50.4 | FFPE | Surgical specimens were retrieved from the institution. A thorough review of clinical data revealed no history of radiation exposure. No selection critera of cPTCs were described. | RET/PTC: Nested PCR |
| Vuong/2016/Japan [23] | University of Yamanashi | 2011 – 2014 | 59 | 49.3 | FFPE | We selected randomly patients with primary PTC who had been initially treated at the institution. No selection criteria of cPTCs were described. | RET/PTC: Nested PCR |
| Lee/2013/Korea [26] | Samsung Medical Center | 2008 – 2009 | 396 | 47.0 | FNAB | Patients who underwent thyroidectomy for primary PTC during the time period were enrolled. No selection criteria of cPTCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Kang/2013/Korea [27] | Samsung Medical Center | 2010 – 2011 | 128 | 48.0 | FFPE | Patients with PTC were randomly retrieved from the surgical pathology files. No selection criteria of cPTCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Zheng/2013/China [24] | Tianjin Medical University Cancer Hospital | 2001 – 2010 | 977 | 46.0 | FFPE | A chart reviewed identified 2046 patients with PTC who underwent surgery during the time period. Among of them, 977 patients had PTMCs. No selection criteria of PTMCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Lu/2013/China [25] | Tianjin Medical University Cancer Hospital | 2013 – 2014 | 1984 | 45.0 a | FFPE | The clinical data was reviewed on 1990 PTMCs during the time period. No selection criteria of PTMCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Barzon/2008/Italy [28] | University of Padova | 2005 – 2007 | 83 | 43.6 | Frozen | Consecutive patients who underwent thyroidectomy at the institution in the selected period and had a pathological diagnosis of PTC. No selection criteria of PTCs were described. | BRAF: Direct sequencing (Applied Biosystem) |
| Pelizzo/2011/Italy [29] | University of Padova | 2008 – 2009 | 270 | 48.9 | FNAB | Consecutive patients within selected time period were prospectively enrolled. All patients had a sonographic single node and/or a node with suspected features who underwent US-guided FNA and subsequent thyroidectomy at the institution. | BRAF: Direct sequencing (Applied Biosystem) |
| Hwang/2009/Korea [30] | Samsung Medical Center | 2008 | 135 | 47.0 | FNAB | Consecutive patients with PTC that had been confirmed surgically were included in the study. All patients underwent ultrasound and ultrasound-guided FNA. | BRAF: Direct sequencing (Applied Biosystem) and allele-specific PCR |
Abbreviations: cPTC, classical papillary thyroid carcinoma; PTMC, papillary thyroid microcarcinoma; FFPE, formalin-fixed paraffin embedded; FNAB, Fine-needle aspiration biopsy
a Median value