Both the presence of a micropapillary component and the micropapillary predominant subtype predict poor prognosis after lung adenocarcinoma resection: a meta-analysis

Table 1 The characteristics of the included studies

First Author (year)	Study Region	Starting and Ending Year	MP Pattern Definition	Total Number of Patients	Number of MP Patients	Age	TNM Staging Distribution				Surgical Approach				Median Follow-up Time	Outcome
First Author (year)	Study Region	Starting and Ending Year	MP Pattern Definition	Total Number of Patients	Number of MP Patients	Age	I	II	III	IV	Lobecto-my	Limited Resection	Pneumon-ectomy	Bilob- ectomy
Presence of micropapillary component
Liu (2014) [17]	China	2007.5–2012.2	MP component	248	79	60 (24–81)	110	30	81	27						OS
Tsubokawa(2016) [18]	Japan	2006.4–2010.12	MP component	347	49	unclear	325	11	11		192	155			40.6	DFS
Moon (2016) [19]	Korea	2010.1–2014.12	MP component	168	37	unclear	133	35			163			3	29.1 (0.4–62.2)	DFS
Yao (2016) [13]	China	2012.9–2014.2	MP component	20	5	62 (43–80)	7	8	5		17	3			30 (24–41)	DFS
Yi (2018) [14]	Korea	2009–2012	MP component	368	141	62.6 (30–91)	368				250	114	1		43 (0–73.9)	DFS
Micropapillary predominant subtype
Westaway (2013) [20]	Australia	2000–2010	MP predominant	152	8	68 (31–100)	79	42	31		133	8	11			OS
Sun (2014) [21]	China	2002.1–2011.12	MP predominant	136	22	57.6 (34–79)	136				119			17	74 (21–145)	DFS, OS
Warth (2015) [22]	Germany	2002–2010	MP predominant	674	53	62.6	264	145	243	22	549	22	87	16	38.2	DFS
Watanabe (2015) [8]	Japan	1998–2007	MP predominant	2316	139	unclear	I + II 1912		III + IV 404							OS
Zhang(2016) [9]	China	2007.1–2010.6	MP predominant	505	49	57 (24–83)	221	81	203		443	19	11	32	43 (22.9–57.5)	DFS, OS

MP pattern definition: Semiquantitative record various patterns that may be present in 5% increments, the presence of MP component is defined as the proportion of MP pattern > 5%, and the MP predominant subtype defined as the MP pattern present in the largest proportion [3, 4]

ISSN: 1749-8090