Representation of cancer in the medical literature--a bibliometric analysis

Abstract

Background: There exists a lack of knowledge regarding the quantity and quality of scientific yield in relation to individual cancer types. We aimed to measure the proportion, quality and relevance of oncology-related articles, and to relate this output to their associated disease burden. By incorporating the impact factor(IF) and Eigenfactor™(EF) into our analysis we also assessed the relationship between these indices and the output under study.

Methods: All publications in 2007 were retrieved for the 26 most common cancers. The top 20 journals ranked by IF and EF in general medicine and oncology, and the presence of each malignancy within these titles was analysed. Journals publishing most prolifically on each cancer were identified and their impact assessed.

Principal findings: 63260 (PubMed) and 126845 (WoS) entries were generated, respectively. 26 neoplasms accounted for 25% of total output from the top medical publications. 5 cancers dominated the first quartile of output in the top oncology journals; breast, prostate, lung, and intestinal cancer, and leukaemia. Journals associated with these cancers were associated with much higher IFs and EFs than those journals associated with the other cancer types under study, although these measures were not equivalent across all sub-specialties. In addition, yield on each cancer was related to its disease burden as measured by its incidence and prevalence.

Conclusions: Oncology enjoys disproportionate representation in the more prestigious medical journals. 5 cancers dominate yield, although this attention is justified given their associated disease burden. The commonly used IF and the recently introduced EF do not correlate in the assessment of the preeminent oncology journals, nor at the level of individual malignancies; there is a need to delineate between proxy measures of quality and the relevance of output when assessing its merit. These results raise significant questions regarding the best method of assessment of research and scientific output in the field of oncology.

Figure 1. Number and Percentage of Publications, Relative to Cancer Incidence.

(a) Publication ratios for 26 most common cancers, ordered by their incidence (b) Percentage of Total Publications Versus Cancer Incidence.

Figure 2. Number and Percentage of Publications, Relative to Cancer Prevalence.

(a) Publication ratios for 23 most common cancers, ordered by their prevalence. Prevalence data was not available for 3 of the cancers; cancer of the gallbladder, vulva, and those involving the soft tissue and heart, (b) Percentage of Total Publications Versus Cancer Prevalence.

Figure 3. Impact Factor Versus Eigenfactor, General Medical Journals.

IF,EF scores, 100 titles in ‘medicine, general and internal’, JCR 2007. Top journals, by IF  =  New England Journal of Medicine (NEJM), Lancet, Journal of American Medical Association (JAMA), Annals of Internal Medicine, & Annual Review of Medicine. Top 5, by EF  =  NEJM, Lancet, JAMA, British Medical Journal (BMJ) and Annals of Internal Medicine.

Figure 4. Impact Factor Versus Eigenfactor Scores, Oncology Journals.

IF,EF scores for 132 titles in category ‘oncology’, JCR 2007. Top 5 journals, by IF  =  Ca:Cancer Journal Clinicians, Nature Reviews Cancer, Cancer Cell, the Journal of the National Cancer Institute, and the Journal of Clinical Oncology (JCO). Top 5, by EF  =  Cancer Research, the JCO, Oncogene, Clinical Cancer Research, and Nature Reviews Cancer.