Demand for biospecimens in cancer research has increased but there are relatively few data on the trends in biospecimen usage. These data are needed to enable projection of future demand. We analyzed biospecimen usage in publications published at five-year intervals (2008, 2003, 1998, 1993, and 1988) in four cancer research journals (Cancer Research, Clinical Cancer Research, British Journal of Cancer and International Journal of Cancer). We categorized publications in three ways: 1) biospecimen utilization yes/no; 2) biospecimen cohort size; and 3) format of biospecimens used including frozen tissue, Formalin-Fixed Paraffin-Embedded (FFPE) tissue, fresh tissue, fluids, and hematological biospecimens. Biospecimens were used in 1292/3307 (39%) of publications analyzed and sufficient information was available to further classify biospecimen usage in 1228 publications. The proportion of publications in each journal using biospecimens ranged from 23% to 61% between journals, with no significant change within each journal over time. A more detailed review of tissue biospecimen use showed a significant increase in cohort sizes from 1988 to 2008 (mean 52 to 198, respectively; P < 0.0001). This reflected increased cohort sizes for both frozen and FFPE tissues from 1993 to 2008 (frozen, 59 to 119; FFPE, 66 to 194) but not fresh tissues. The relative proportion of studies using frozen or fresh tissues alone has decreased (71% to 24%) while those using FFPE alone or combined FFPE/frozen tissue cohorts has increased (24% to 72%) over this period. We conclude that the overall demand for biospecimens in cancer research has increased significantly (almost fourfold) over the past 20 years. We predict that average cohort sizes will increase by at least twofold for frozen and FFPE biospecimens over the next ten years, and that the majority of studies will be based on FFPE tissues or combined FFPE/Frozen tissue cohorts.