Systematic Reviews
Copyright ©The Author(s) 2017.
World J Meta-Anal. Apr 26, 2017; 5(2): 41-53
Published online Apr 26, 2017. doi: 10.13105/wjma.v5.i2.41
Table 1 Characteristics of the included meta-analyses
First author, Yeara (Country)bDatabases searched (Period)cStudies included (n)Studies published between (Years)Total subjects involvedTotal cancer casesHeterogeneity presents?Pooled RR (95%CI) for primary outcome (n)dPooled RR (95%CI) for secondary outcome (n)Pooled RR (95%CI) for Sub-group analysiseAMSTAR score
Bladder cancer
Zhang X, 2013 (China)[15]MEDLINE, EMBASE and Ovid (January 1966 to October 2012)RCTs (3), Cohort (5) and CC (5)2001-201212662682511Yes (q = 0.001, I2 = 62.6%)1.07 (0.95-1.21) (↔)LSU = 1.21 (0.92-1.51) (8) (↔)RCTs = 0.83 (0.63-1.10) (↔); Cohort = 1.11 (0.91-1.35) (↔); CC = 1.12 (0.98-1.28) (↔)7
Breast cancer
Bonovas S, 2005 (Greece)[16]MEDLINE (1966 to March2005) and SCI (1970 to March2005)RCTs (7), Cohort (4) and CC (5)1993-200532723824599No (q = 0.12, I2 = 30%)1.03 (0.93-1.14) (↔)NoneRCTs = 1.04 (0.81-1.33) (↔) ; Cohort = 1.06 (0.92-1.21) (↔); CC = 0.99 (0.83-1.18) (↔)7
Undela K, 2012 (India)[17]PubMed (1966 to January 2012) and ASCO, AACR conference abstractsCohort (13) and CC (11)1993-2011244098876759Yes (q < 0.001, I2 = 57%)0.99 (0.94-1.04) (↔)LSU = 1.03 (0.96-1.11) (10) (↔); Recurrence 0.53 (0.37-0.76) (2) (↓)Cohort = 1.01 (0.98-1.04) (↔); CC = 0.95 (0.84-1.08) (↔)5
Colorectal cancer
Bonovas S, 2007 (Greece)[18]MEDLINE (1966 to December 2006) and WS (1970 to December 2006)RCTs (6), Cohort (3) and CC (9)2000-2007152772138734No (q = 0.35, I2 = 7%)0.92 (0.90-0.95) (↓)NoneRCTs = 0.95 (0.81-1.11) (↔); Cohort = 0.96 (0.84-1.11) (↔); CC = 0.92 (0.89-0.95) (↓)7
Bardou M, 2010 (Canada)f[47]EMBASE, MEDLINE, CENTRAL, and ISI WKRCTs (11)NA959841659No (NA)0.94 (0.85-1.04) (↔)NoneNA--
Bardou M, 2010 (Canada)f[48]EMBASE, MEDLINE, CENTRAL, and ISI WKCohort (8) and CC (13)NA1606234NANo (NA)0.92 (0.87-0.98) (↓)NoneCohort = 0.89 (0.75-1.05) (↔); CC = 0.92 (0.90-0.94) (↓)--
Ditah I, 2010 (United States)[49]fNARCTs (6), Cohort (6) and CC (12)Up to Jun 2010> 1.7 millionNANA0.89 (0.85-0.94) (↓)NoneRCTs = 0.95 (0.80-1.13) (↔); Cohort = 0.89 (0.85-0.94) (↓); CC = 0.86 (0.79-0.94) (↓)--
Samadder NJ, 2010 (United States)[50]fMEDLINE, EMBASE, WS and abstracts of national GI conferences (up to October 2009)Cohort (5) and CC (17)NA2.5 millionNAYes (q < 0.01, I2 = 47%)0.88 (0.84-0.93) (↓)Rectal = 0.81 (0.62-1.05) (8) (↓)Cohort = 0.88 (0.84-0.93) (↓); CC = 0.90 (0.86-0.94) (↓)--
Liu Y, 2014 (China)[19]PubMed, EMBASE, WS, Cochrane Library (up to 30th July 2013)RCTs (11), Cohort (13) and CC (18)1995-20137908674519317Yes (q < 0.001, I2 = 66.5%)0.90 (0.86-0.95) (↓)LSU = 0.96 (0.88-1.04) (20) (↔)RCTs = 0.96, (0.85-1.08) (↔); Cohort = 0.93 (0.87-0.99) (↓); CC = 0.84 (0.76-0.93) (↓)7
Lytras T, 2014 (Greece)[20]MEDLINE (1966 to July 2013)RCTs (8), Cohort (13) and CC (19)1996-20138224019130992Yes (q < 0.001, I2 = 71%)0.91 (0.87-0.96) (↓)NoneRCTs = 0.90 (0.78-1.04) (↔); Cohort = 0.91 (0.83-1.00) (↓); CC = 0.92 (0.87-0.98) (↓)0034
Gastric cancer
Shimoyama S, 2011 (Japan)[21]PubMed Central (1993 to 2008)RCTs (6)1994-200737851284No (q = 0.42, I2 = 0.0%)1.37 (0.57-3.25) (3) (↔)UGIC = 1.20 (0.94-1.53) (3) (↔)None0
Singh PP, 2013 (United States)[22]PubMed (1966 to 1st December 2012), EMBASE (1988 toRCTs (post-hoc analyses) (3),2004-201254599755581Yes (q < 0.01, I2 = 89%)0.68 (0.51-0.91) (↓)NoneRCTs = 0.83 (0.66-1.05) (↔); OSs = 0.65 (0.45-0.93) (↓)8
1st December 2012) and WS (1993 to 1st December 2012)Cohort (1) and CC (7)
Wu X, 2013 (China)[23]PubMed and EMBASE (up to March 2013)RCTs (3), Cohort (3) and CC (5)2004-201311369187611Yes (q < 0.001, I2 = 88.9%)0.73 (0.58-0.93) (↓)NoneRCTs = 0.84 (0.61-1.14) (↔); Cohort = 0.87 (0.77-0.99) (↓); CC = 0.56 (0.31-1.01) (↔)6
Ma Z, 2014 (China)[24]Cochrane CRCT (Issue 12, 2012), PubMed, EMBASE, ISI WK, CNKI, CBML, CSJFD and Wanfang DatabaseCC (6)2004-2013607935993Yes (q < 0.001, I2 = 97%)0.56 (0.35-0.90) (↓)NoneNone6
Gynaecologic cancer
Liu Y, 2014 (China)[25]PubMed, EMBASE and Cochrane Library (up to 10th February 2014)RCTs (4), Cohort (5) and CC (5)2000-201392872112904Yes (q = 0.016, I2 = 42.3%)0.89 (0.78-1.01) (↔)Endometrial = 0.90 (0.75-1.07) (10) (↔); Ovarian = 0.79 (0.64-0.98) (5) (↓)RCTs = 0.97 (0.62-1.50) (↔); Cohort = 0.97 (0.87-1.09) (↔); CC = 0.61 (0.40-0.91) (↓)7
Haematological cancer
Bonovas S, 2007 (Greece)[26]MEDLINE (1966 to December 2006) and WS (1970 to December 2006)RCTs (6), Cohort (1) and CC (7)1996-20064120535619Yes (q < 0.001, I2 = 71%)0.85 (0.64-1.12) (↔)NoneRCTs = 0.92 (0.72-1.16) (↔); OSs = 0.83 (0.53-1.29) (↔)5
Yi X, 2014 (China)[27]PubMed, EMBASE and Cochrane CRCT (January 1966 to July 2013)RCTs (6), Cohort (4), CC (10)1996-2012113958415297Yes (q < 0.001, I2 = 59%)0.81 (0.70-0.92) (↓)NoneRCTs = 0.92 (0.77-1.09) (↔); OSs = 0.79 (0.67-0.93) (↓)4
Kidney cancer
Zhang X, 2014 (China)[28]MEDLINE, EMBASE and Cochrane Library (January 1966 to October 2012)RCTs (2), Cohort (5) and CC (5)2001- 201231432362829Yes (q < 0.001, I2 = 87.8%)0.92 (0.71- 1.19) (↔)LSU = 1.01 (0.83-1.22) (6) (↔)RCTs = 1.01 (0.57-1.79) (↔); Cohort = 1.07 (0.96-1.20) (↔); CC = 0.74 (0.45-1.23) (↔)5
Liver cancer
Pradelli D, 2013 (Italy)[29]MEDLINE (up to March 2012)Cohort (3) and CC (2)NANA2574Yes (q < 0.001, I2 = 65%)0.58 (0.46-0.74) (↓)LSU = 0.66 (0.55-0.80) (↓)None6
Singh S, 2013 (United States)[30]MEDLINE (1966 to 25th May 2012), EMBASE (1988 to 25th May 2012) and WS (1993 to 25th May 2012)RCTs (3), Cohort (4) and CC (3)2005-201214594174298Yes (q = 0.08, I2 = 58%)0.63 (0.52-0.76) (↓)NoneRCTs = 0.95 (0.62-1.45) (↔); OSs = 0.60 (0.49-0.73) (↓)8
Zhang H, 2013 (China)[52]MEDLINE, EMBASE and Cochrane Library (January 1966 to March2013)Cohort (4) and CC (3)2005-201347255939785Yes (q = 0.004, I2 = 68.6%)0.61 (0.49-0.76) (↓)NoneCohort = 0.62 (0.3-0.89) (↓); CC = 0.63 (0.49-0.82) (↓)5
Shi M, 2014 (China)[31]PubMed, BIOSIS Previews, WS, EMBASE, EBSCO and Cochrane LibraryRCT (IPD analysis) (1), Cohort (5) and CC (6)2005-2013564031335756Yes (q < 0.001, I2 = 65%)0.58 (0.51-0.67) (↓)HCDS = 0.53 (0.36-0.79) (6) (↓)RCT = 1.06 (0.66-1.71) (↔); Cohort = 0.51 (0.44-0.58) (↓); CC = 0.63 (0.54-0.73) (↓)6
(from inception to 5th March 2014)
Lung cancer
Deng Z, 2013 (China)[32]gMEDLINE, EMBASE and WS (from inception to September 2013)RCTs (8) Cohort (7) and CC (8)1998-2012279530238024OSs = Yes (q < 0.001, I2 = 94.9%) RCTs = No (q = 0.483, I2 = 0.0%)1.03 (0.96-1.11) (↔)NoneRCTs = 0.95 (0.85-1.06) (↔); Cohort = 0.94 (0.82-1.07) (↔); CC = 0.85 (0.62-1.16) (↔)6
Tan M, 2013 (China)[33]PubMed (up to March 2012)RCTs (5), Cohort (7) and CC (7)1998-2011500940438013Yes (q < 0.001, I2 = 93.3%)0.89 (0.77-1.03) (↔)LSU = 0.81 (0.42-1.56) (↔)RCTs = 0.91 (0.76-1.09) (↔); Cohort = 0.94 (0.82-1.07) (↔); CC = 0.82 (0.57-1.16) (↔)6
Wang J, 2013 (China)[34]MEDLINE, EMBASE and Cochrane Library (January 1966 to November 2012)RCTs (5), Cohort (8) and CC (7)1998-2012498000937560Yes (q < 0.001, I2 = 93.6%)0.89 (0.78-1.02) (↔)LSU = 0.80 (0.39-1.64) (6) (↔)RCTs = 0.92 (0.79-1.06) (↔); Cohort = 0.93 (0.82-1.06) (↔); CC = 0.81 (0.57-1.16) (↔)8
Oesophageal cancer
Alexandre L, 2012 (United Kingdom)[35]PubMed, EMBASE and Cochrane CRCT (up to December 2011)Cohort (3)2004-2011352149310No (q = 0.88, I2 = 0.0%)0.86 (0.78-0.94) (↓)In patients with BE = 0.53 (0.36-0.78) (↓)None7
Andrici J, 2013 (Australia)f[51]MEDLINE, PubMed, EMBASE and Current Contents Connect (up to 29th October 2012)7 studiesNANANANo (q = 0.31, I2 = 15%)0.75 (0.67-0.84) (↓)In patients with BE = 0.56 (0.41-0.76) (↓); LSU = 0.45 (0.31-0.67) (↓)Prospective = 0.75 (0.67-0.86) (↓); Retrospective = 0.68 (0.54-0.86) (↓)--
Beales ILP, 2013 (United Kingdom)[36]The PubMed, EMBASE, Cochrane Library, WS, Wiley Interscience and Google Scholar (up to 1st February 2013)Cohort (5) and CC (6)2004-20126454353371203No (q = 0.42, I2 = 0.0%)0.81 (0.75-0.88) (6) (↓)In patients with BE = 0.56 (0.41-0.76) (4) (↓)None6
Singh S, 2013 (United States)[37]MEDLINE (1980 to 31st Aug 2012), EMBASE (1988 to 31st Aug 2012) and WS (1993 to 31st August 2012)RCT (Post hoc analyses) (1), Cohort (5) and CC (7)2004-201211329699285Yes (q < 0.01, I2 = 74%)0.72 (0.60-0.86) (↓)In patients with BE = 0.59 (0.45-0.78) (5) (↓); LSU = 0.44 (0.24-0.78) (2) (↓)RCT = 0.98 (0.69-1.40) (↔); Cohort = 0.79 (0.62-1.02) (↔); CC = 0.66 (0.51-0.85) (↓)8
Pancreatic cancer
Bonovas S, 2008 (Greece)[38]MEDLINE, Scopus, Google Scholar, and SCI (up to December 2007) and AACO and AACR conference abstractsRCTs (3), Cohort (4) and CC (5)1993-20079146013521Yes (q < 0.001, I2 = 86%)0.88 (0.63-1.23) (↔)NoneRCTs = 0.99 (0.44-2.21) (↔); Cohort = 1.11 (0.95-1.29) (↔); CC = 0.70 (0.37-1.33) (↔)7
Cui X, 2012 (China)[39]MEDLINE, BIOSIS Previews and Cochrane Library (from inception to 30th August 2011)RCTs (3), Cohort (5) and CC (8)2001-201116928637807Yes (q < 0.001, I2 = 81%)0.89 (0.74-1.07) (↔)LSU = 0.97 (0.76-1.23) (5) (↔)RCTs = 0.99 (0.44-2.21) (↔); Cohort = 1.05 (0.93-1.19) (↔); CC = 0.74 (0.51-1.07) (↔)8
Prostate cancer
Bonovas S, 2008 (Greece)[40]MEDLINE (1966 to November 2007) and WK-SCI ExpandedRCTs (6), Cohort (6) and CC (7)1993-2007> 88487162372Yes (q < 0.001, I2 = 98%)0.95 (0.73-1.23) (↔)LSU = 0.93 (0.77-1.13) (6) (↔); APC = 0.77 (0.64-0.93) (5) (↓)RCTs = 1.06 (0.93-1.20) (↔); Cohort = 0.98 (0.89-1.09) (↔); CC = 0.74 (0.46-1.20) (↔)5
(1970 to November 2007)
Bansal D, 2012 (India)[41]PubMed (up to February 2012)Cohort (15) and Case-control (12)1993-2011189357156847Yes (q < 0.001, I2 = 82%)0.93 (0.87-0.99) (↓)LSU = 0.94 (0.84-1.05) (11) (↔); APC = 0.80 (0.70-0.90) (7) (↓)Cohort = 0.93 (0.87-1.01) (↔); CC = 0.87 (0.72-1.05) (↔)7
Zhang Y, 2013 (China)[42]NA7 studies2005-2010NANANA1.19 (1.01-1.40) (↑)NANA6
Skin cancer (Melanoma)
Dellavalle R, 2005 (United States)[43]Cochrane Skin Group Specialised Register (up to February 2003) and CENTRAL (Issue 1, 2005), MEDLINE (up to March 2003), EMBASE (up to September 2003), CANCERLIT (up to October 2002), WS (up to May 2003)RCTs (7)1993-199831198126No (q = 0.23, I2 = 29%)0.90 (0.56-1.44) (↔)Lovastatin = 0.52 (0.27-0.99) (1) (↓)None10
Freeman SR, 2006 (United States)[44]MEDLINE (from January 1966 to March 2003), EMBASE (from January 1980 to September 2003), The Cochrane CRCT (up to March2003), CANCERLIT (from January 1975 to October 2002), and WS - SCI (from January 1970 to May 2003)RCTs (12)1993-200339426127No (q = 0.31, I2 = 16.6%)0.87 (0.61-1.23) (↔)Lovastatin = 0.52 (0.27-0.99) (1) (↓)None6
Bonovas S, 2010 (Greece)[45]MEDLINE, Scopus, Google Scholar and SCI Expanded (up to June 2009)RCTs (16)1994-200662568165No (q = 0.25, I2 = 22%)0.92 (0.67-1.26) (↔)NoneNone6
Li X, 2014 (China)[46]PubMed ( up to 2013) anwd WS (1985-2013)RCTs (17), Cohort (4) and CC (7)1995-201351788711787Yes (q < 0.07, I2 = 33.8%)0.94 (0.85-1.04) (24) (↔); NMSC = 1.03 (0.90-1.19) (14) (↔)NoneNone4
aPublication year;
bCountry of study conducted;
cPeriod of literature search;
dn mentioned only where the number of studies differ from studies included;
eThough many subgroup analyses conducted in individual studies, here we focused mainly on subgroup analysis based on study design due to space constraint;
fConference abstracts;
gConducted among elderly people. APC: Advanced prostate cancer; BE: Barrett’s oesophagus; CBML: China BioMedical Literature; CC: Case-control; CNKI: Chinese National Knowledge Infrastructure; CRCT: Central Register of Controlled Trials; CSJFD: Chinese Scientific Journal Full-text Database; GI: Gastro-intestinal; HCDS: Higher cumulative dosage of statin; I2: I2 test value; IPD: Individual patient data; ISI WK: Institute for Scientific Information Web of knowledge (Former term for Web of science); LSU: Long-term statin use; n: Number of studies; NA: Not available; NMSC: Non-melanoma skin cancer; Oss: Observational studies; q: Cochran Q test P value; RCTs: Randomized controlled trials; RR: Relative risk; SCI: Science citation index; UGIC: Upper gastrointestinal cancer; WS: Web of science; ↔: Non-significant association; ↓: Statistically significantly decreased risk; ↑: Statistically significantly increased risk.