Table 1 Descriptive statistics of eligible studies

Year

2000–2013

13 (12 %)

2013–2014

23 (21 %)

2014–2014

0 (0 %)

2014–2015

75 (68 %)

N

111 (100 %)

Cancer site

Gastric

16 (13 %)

Colorectal

15 (12 %)

Lung

15 (12 %)

Brain

12 (9 %)

Esophageal

10 (8 %)

Prostate

10 (8 %)

Hepatic

9 (7 %)

Breast

6 (5 %)

Pancreatic

6 (5 %)

Cervical

5 (4 %)

Head and neck

4 (3 %)

Ovarian

4 (3 %)

Renal

4 (3 %)

Urinary bladder

4 (3 %)

Any

2 (2 %)

Hematologic

2 (2 %)

Endometrial

1 (1 %)

GIST

1 (1 %)

Neuroblastoma

1 (1 %)

N

127 (100 %)

Agnostic ^a

No

85 (77 %)

Yes

21 (19 %)

Agnostic parent

5 (5 %)

N

111 (100 %)

Survival analysis

OS

92 (83 %)

RFS

36 (32 %)

DSS

10 (9 %)

MFS

9 (8 %)

PFS

6 (5 %)

N

111 (100 %)

Quantification method

qRT-PCR

84 (66 %)

ISH

28 (22 %)

qPCR

11 (9 %)

qRT-PCR or ISH

2 (2 %)

RT-qPCR

1 (1 %)

Unreported

1 (1 %)

N

127 (100 %)

Continent

Asia

94 (74 %)

Europe

15 (12 %)

America

13 (10 %)

Multiple

3 (2 %)

Unreported

2 (2 %)

N

127 (100 %)

Study design

Unreported

106 (83 %)

Retrospective

19 (15 %)

Prospective

2 (2 %)

N

127 (100 %)

Sampling method

Unreported

113 (89 %)

Consecutive

5 (4 %)

Population

5 (4 %)

Random

4 (3 %)

N

127 (100 %)

Tissue preservation ^b

L

66 (52 %)

Unreported

34 (27 %)

P

18 (14 %)

LP

6 (5 %)

L + RNALater

3 (2 %)

N

127 (100 %)

Pre-biopsy treatment

No

77 (61 %)

Unreported

46 (36 %)

Yes

4 (3 %)

N

127 (100 %)

Post-biopsy treatment

Unreported

98 (77 %)

Yes

27 (21 %)

No

2 (2 %)

N

127 (100 %)

Total number of lncRNAs studied

1

87 (78 %)

2–10

4 (4 %)

11–45033

15 (14 %)

Unreported

5 (5 %)

N

111 (100 %)

Outcomes

Clinical and Non-clinical

76 (68 %)

Clinical only

35 (32 %)

N

111 (100 %)

Use of validation method for survival

Unreported

99 (89 %)

External

5 (5 %)

Internal

4 (4 %)

Both

2 (2 %)

Yes

1 (1 %)

N

111 (100 %)