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Contradictory results of a more extensive search on cruciferous vegetables and breast cancer
The Breast 21 (2012) 783
Contents lists available at SciVerse ScienceDirect
The Breast journal homepage: www.elsevier.com/brst
Letter to the Editor
Contradictory results of a more extensive search on cruciferous vegetables and breast cancer A recent article in The Breast describes a meta-analysis on the effect of cruciferous vegetables and the risk of breast cancer.1 The authors conclude that more research is needed, because of the small number of studies found and they especially ask for large prospective cohort studies. The reason the authors found only a small number of studies (53) was their limited search. A more systematic search would have retrieved more relevant papers. The authors specifically searched for ’risk’ where all articles on brassica and breast cancer are potentially relevant, and they included additional articles not on brassica. The 408 references we retrieved in PubMed included, among several relevant studies,2–5 two large cohort studies (in total 4000 cases, 130,000 subjects) not included in the original review6,7 that specifically investigated the association of broccoli and other vegetable consumption on breast cancer without finding a relevant effect. When performing a systematic review or meta-analysis, researchers should always consult a medical information specialist/ clinical librarian to optimize their searches. This will lead to more complete and objective results. The widely recognized Prisma Statement8 as well as the Cochrane Handbook9 state the demands for searching and reporting systematic reviews. Appendix A. PubMed search strategy on cruciferous vegetables and breast cancer
#5 #4 #3 #2 #1
1. Liu X, Lv K. Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis. Breast, http://dx.doi.org/10.1016/j.breast.2012. 07.013; 2012. 2. Velie EM, Schairer C, Flood A, He JP, Khattree R, Schatzkin A. Empirically derived dietary patterns and risk of postmenopausal breast cancer in a large prospective cohort study. Am J Clin Nutr 2005;82:1308–19. 3. Huang XE, Hirose K, Wakai K, Matsuo K, Ito H, Xiang J, et al. Comparison of lifestyle risk factors by family history for gastric, breast, lung and colorectal cancer. Asian Pac J Cancer Prev 2004;5:419–27. 4. Cui X, Dai Q, Tseng M, Shu XO, Gao YT, Zheng W. Dietary patterns and breast cancer risk in the shanghai breast cancer study. Cancer Epidemiol Biomarkers Prev 2007;16:1443–8. 5. Malin AS, Qi D, Shu XO, Gao YT, Friedmann JM, Jin F, et al. Intake of fruits, vegetables and selected micronutrients in relation to the risk of breast cancer. Int J Cancer 2003;105:413–8. 6. Wang L, Lee IM, Zhang SM, Blumberg JB, Buring JE, Sesso HD. Dietary intake of selected flavonols, flavones, and flavonoid-rich foods and risk of cancer in middle-aged and older women. Am J Clin Nutr 2009;89:905–12. 7. Adebamowo CA, Cho E, Sampson L, Katan MB, Spiegelman D, Willett WC, et al. Dietary flavonols and flavonol-rich foods intake and the risk of breast cancer. Int J Cancer 2005;114:628–33. 8. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 2009;62:e1–34. 9. Higgins JPT, Green S. Cochrane handbook for systematic reviews of interventions. Available from: http://www.cochrane-handbook.org/ [cited 2012 August 23].
Wichor M. Bramer* Biomedical Information Specialist, Medical Library, Erasmus MC – University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
Search executed 3 September 2012.
Search Query
References
Items found
#4 NOT ((Animals[mh] OR Plants[mh]) NOT Humans[mh]) 408 #1 AND #2 AND #3 629 breast[mh] OR breast neoplasms[mh] OR breast*[tiab] 569947 OR mamma*[tiab] OR nipple*[tiab] cancer[sb] 4418245 Brassicaceae[mh] OR brassica*[tiab] OR collard green*[tiab] 68053 OR broccoli*[tiab] OR kale*[tiab] OR cabbage*[tiab] OR (cauliflower*[tiab] NOT cauliflower like*[tiab]) OR brussel sprout*[tiab] OR brussels sprout*[tiab] OR crucifer*[tiab] OR arugula*[tiab] OR bok choy*[tiab] OR chard*[tiab] OR daikou*[tiab] OR kohlrabi*[tiab] OR mustard green*[tiab] OR radish*[tiab] OR horseradish*[tiab] OR turnip*[tiab] OR watercress*[tiab] OR gardencress*[tiab] OR wasabi*[tiab] OR mustard seed*[tiab] OR rutabaga*[tiab] OR rapeseed *[tiab] OR cress[tiab] OR cresses[tiab] OR barbarea[tiab] OR lepidium*[tiab] OR nasturtium*[tiab] OR tropaeolum *[tiab] OR raphanus[tiab]
[mh] ¼ MeSH terms [tiab] ¼ words in title or abstract [sb] ¼ PubMed subset (see http://www.nlm.nih.gov/bsd/pubmed_subsets/cancer_strategy.html for the full strategy). 0960-9776/$ – see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.breast.2012.10.003
Johannes C.F. Ket Medical Information Specialist, Medical Library, Sint Lucas Andreas Ziekenhuis, Amsterdam, The Netherlands Bianca M.R. Kramer Information Specialist Health and Medical Sciences, University Library Utrecht University, Utrecht, The Nederlands * Corresponding author. E-mail address: [email protected] (W.M. Bramer) 3 September 2012
Contents lists available at SciVerse ScienceDirect
The Breast journal homepage: www.elsevier.com/brst
Letter to the Editor
Contradictory results of a more extensive search on cruciferous vegetables and breast cancer A recent article in The Breast describes a meta-analysis on the effect of cruciferous vegetables and the risk of breast cancer.1 The authors conclude that more research is needed, because of the small number of studies found and they especially ask for large prospective cohort studies. The reason the authors found only a small number of studies (53) was their limited search. A more systematic search would have retrieved more relevant papers. The authors specifically searched for ’risk’ where all articles on brassica and breast cancer are potentially relevant, and they included additional articles not on brassica. The 408 references we retrieved in PubMed included, among several relevant studies,2–5 two large cohort studies (in total 4000 cases, 130,000 subjects) not included in the original review6,7 that specifically investigated the association of broccoli and other vegetable consumption on breast cancer without finding a relevant effect. When performing a systematic review or meta-analysis, researchers should always consult a medical information specialist/ clinical librarian to optimize their searches. This will lead to more complete and objective results. The widely recognized Prisma Statement8 as well as the Cochrane Handbook9 state the demands for searching and reporting systematic reviews. Appendix A. PubMed search strategy on cruciferous vegetables and breast cancer
#5 #4 #3 #2 #1
1. Liu X, Lv K. Cruciferous vegetables intake is inversely associated with risk of breast cancer: a meta-analysis. Breast, http://dx.doi.org/10.1016/j.breast.2012. 07.013; 2012. 2. Velie EM, Schairer C, Flood A, He JP, Khattree R, Schatzkin A. Empirically derived dietary patterns and risk of postmenopausal breast cancer in a large prospective cohort study. Am J Clin Nutr 2005;82:1308–19. 3. Huang XE, Hirose K, Wakai K, Matsuo K, Ito H, Xiang J, et al. Comparison of lifestyle risk factors by family history for gastric, breast, lung and colorectal cancer. Asian Pac J Cancer Prev 2004;5:419–27. 4. Cui X, Dai Q, Tseng M, Shu XO, Gao YT, Zheng W. Dietary patterns and breast cancer risk in the shanghai breast cancer study. Cancer Epidemiol Biomarkers Prev 2007;16:1443–8. 5. Malin AS, Qi D, Shu XO, Gao YT, Friedmann JM, Jin F, et al. Intake of fruits, vegetables and selected micronutrients in relation to the risk of breast cancer. Int J Cancer 2003;105:413–8. 6. Wang L, Lee IM, Zhang SM, Blumberg JB, Buring JE, Sesso HD. Dietary intake of selected flavonols, flavones, and flavonoid-rich foods and risk of cancer in middle-aged and older women. Am J Clin Nutr 2009;89:905–12. 7. Adebamowo CA, Cho E, Sampson L, Katan MB, Spiegelman D, Willett WC, et al. Dietary flavonols and flavonol-rich foods intake and the risk of breast cancer. Int J Cancer 2005;114:628–33. 8. Liberati A, Altman DG, Tetzlaff J, Mulrow C, Gøtzsche PC, Ioannidis JP, et al. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration. J Clin Epidemiol 2009;62:e1–34. 9. Higgins JPT, Green S. Cochrane handbook for systematic reviews of interventions. Available from: http://www.cochrane-handbook.org/ [cited 2012 August 23].
Wichor M. Bramer* Biomedical Information Specialist, Medical Library, Erasmus MC – University Medical Center Rotterdam, 3000 CA Rotterdam, The Netherlands
Search executed 3 September 2012.
Search Query
References
Items found
#4 NOT ((Animals[mh] OR Plants[mh]) NOT Humans[mh]) 408 #1 AND #2 AND #3 629 breast[mh] OR breast neoplasms[mh] OR breast*[tiab] 569947 OR mamma*[tiab] OR nipple*[tiab] cancer[sb] 4418245 Brassicaceae[mh] OR brassica*[tiab] OR collard green*[tiab] 68053 OR broccoli*[tiab] OR kale*[tiab] OR cabbage*[tiab] OR (cauliflower*[tiab] NOT cauliflower like*[tiab]) OR brussel sprout*[tiab] OR brussels sprout*[tiab] OR crucifer*[tiab] OR arugula*[tiab] OR bok choy*[tiab] OR chard*[tiab] OR daikou*[tiab] OR kohlrabi*[tiab] OR mustard green*[tiab] OR radish*[tiab] OR horseradish*[tiab] OR turnip*[tiab] OR watercress*[tiab] OR gardencress*[tiab] OR wasabi*[tiab] OR mustard seed*[tiab] OR rutabaga*[tiab] OR rapeseed *[tiab] OR cress[tiab] OR cresses[tiab] OR barbarea[tiab] OR lepidium*[tiab] OR nasturtium*[tiab] OR tropaeolum *[tiab] OR raphanus[tiab]
[mh] ¼ MeSH terms [tiab] ¼ words in title or abstract [sb] ¼ PubMed subset (see http://www.nlm.nih.gov/bsd/pubmed_subsets/cancer_strategy.html for the full strategy). 0960-9776/$ – see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.breast.2012.10.003
Johannes C.F. Ket Medical Information Specialist, Medical Library, Sint Lucas Andreas Ziekenhuis, Amsterdam, The Netherlands Bianca M.R. Kramer Information Specialist Health and Medical Sciences, University Library Utrecht University, Utrecht, The Nederlands * Corresponding author. E-mail address: [email protected] (W.M. Bramer) 3 September 2012