Table 1. Characteristics of studies included in the meta-analysis.

Study	Country	Study period	No. of cases (non-responders)	No. of all patients	Adjustment	Follow-up period
Xie 2016 [17]	China	2003–2008	18	52	Tumor size, the expression of ALDH1	3–123 months
Fuso 2005 [29]	Italy	1997–2004	26	73	Na.	3–140 months
Liu 2013 [18]	China	2002–2011	40	103	Na.	6–113 months
Martinelli 2015 [31]	Italy	1990–2011	60	275	Pathologic response, Vaginal involvement, Lymph nodes positivity	4–119 months
Yang 2015 [30]	China	2007–2012	33	115	Na.	6–75 months
Mori 2010 [32]	Japan	2002–2006	4	30	Na.	26–83 months
Li 2012 [33]	China	2000–2011	43	154	Na.	6–142 months
Shoji 2013 [34]	Japan	2002–2011	5	23	Na.	9–90 months