Supplementary Data 4. Newcastle-Ottawa Scale quality assessment analysis.

Article	Selection	Comparability	Exposure	Total stars
Meijer-Jorna [4]	1b, 2a 3a 4a	1a, age sex and location	1a 2a 3a	3
Meijer- Jorna [16]	1b 2a 3a 4a	1a demographic data, location, flow analysis, and prior treatment	1a 2a 3a	3
Meijer- Jorna [28]	1b 2a 3a 4a	1a cases and controls same person,	1a 2a 3a	3
Lu [117]	1a 2a 3a 4a	Patients characteristics unclear	1a 2a 3a	3
Zhan [29]	1a 2a 3a 4a	Patients characteristics somewhat similar previous surgery not mentioned cases and controls same person	1d 2a 3a	3
Pavlov [18]	1a 2a 3a 4a	Case and control same person, similar characteristics, and recurrence recorded	1a 2a 3a	3
Pavlov [19]	1a 2a 3a 4a	Case and control same person,	1a 2a 3a	3
Wautier [23]	1a 2b 3a 4a	Small number of cultured cells (only from two patients)	1a 2a 3c	3
Liu [17]	1a 2a 3a 4a	1a	1b 2a(28y) 3a	3
Marler [15]	1a 2b 3a 4	1a	1a 2a	3
Kulungowski [26]	1a 2a 3a 4a	Age sex location type of anomaly	1a 2a 3a	3
Maclellan [25]	1a 2a 3a 4a	Age sex location type of anomaly	1a 2a 3a	3
Dawson [24]	1a 2a 3a 4a	1a	1a 2a 3a	3
Duyka [27]	1a 2a 3a 4a	1a	1a 2a 3a	3
Redondo [11]	1a 2a 3c 4c	1a	1a 2a 3 NA	3
Ryu [22]	1a 2a 3b 4a	Case–Control	1a 2a 3a	3