Table 1.

Overview of included studies.

	Author	Country	Year	S	NS	n (cT3)	TL	OP	2-Year OS		3-Year OS		5-Year OS		5-Year DSS		Type of Non-Surgical Organ Preservation
									TL *	OP *	TL *	OP *	TL *	OP *	TL *	OP *
1	Bryant et al. [12]	Australia	1995	R	7	97	42	55							18	28	RT alone
2	Kowalski et al. [13]	Brazil	1996	R	7	221	176	45	39	27	51	28	69	29			RT alone
3	Porter et al. [14]	NZ	1998	R	7	71	46	25							16	17	RT alone
4	Thakar et al. [15]	India	2000	R	7	119	65	54	13	14	13	17	18	25			RT alone
5	Nguyen-Tan et al. [16]	USA	2001	R	7	83	70	13									CRT
6	Sessions et al. [17]	USA	2002	R	7	65	36	29					16	16	10	13	RT alone
7	Dziegielewski et al. [18]	Canada	2012	R	7	126	35	91	4	34	8	46	11	63			Both CRT and RT, separate data available
8	Karlsson et al. [19]	Sweden	2014	R	7	71	17	54									CRT and RT, separately not specified in data
9	Timme et al. [20]	USA	2015	R	7	44	19	25	2	7	5	6	11	16			CRT
10	Connor et al. [21]	Scotland	2015	R	7	106	30	76							2	21	Both CRT and RT, separate data available
11	Timmermans et al. [22]	Netherlands	2016	R	7	1922	324	1598	109	510	131	661	180	973			CRT and RT, separately not specified in data
12	Daneshi et al. [23]	Iran	2018	R	7	151	127	24			27	13	37	15			CRT
13	Čoček et al. [24]	Czech Rep.	2018	R	7	70	45	25	8	6	11	8	17	13			CRT and RT, separately not specified in data
14	Bates et al. [25]	USA	2019	R	7	7569	1044	6525	282	1631	407	2414	522	3067			CRT
15	Shi et al. [26]	USA	2021	R	7	88	32	56	7	20	9	24	19	32			CRT
16	Lee et al. [27]	USA	2023	R	7	137	41	96	16	19	20	32	26	51			CRT and RT, not specified in data

All the included studies were level 3 evidence as per the Oxford Centre for Based Medicine (OCEBM) criteria. S—Study type, R—Retrospective, NS—Newcastle–Ottawa Scale, NZ—New Zealand, OS—Overall survival, DSS—Disease-specific survival, TL—Total laryngectomy, OP—Organ preservation, *—Events. CRT—Chemoradiation. RT—Radiation alone.