Study Design
Unique Values of the Prospective Cohort Incident-Tumor Biobank Method for Transdisciplinary Cancer Epidemiology Shuji Ogino* Shuji Ogino Tomotaka Ugai
The prospective cohort incident-tumor biobank method (PCIBM) is an unconventional design/method that utilizes a tissue biobank of incident cancer/precancer cases that have occurred in a prospective cohort study. Any prospective cohort study that has accumulated long-term exposure data and given rise to incident tumor cases with available tissues allows research using this method. PCIBM’s advantages over tumor tissue-based case-control studies include: 1) the availability of long-term exposure data before cancer diagnosis; 2) less recall bias in past exposures; 3) no differential recall bias in prediagnosis exposures between cancer vs. cancer-free participants; and 4) less patient selection bias. We illustrate the PCIBM, using the Nurses’ Health Study (NHS), NHS II, and Health Professionals Follow-up Study, which enrolled over 280,000 participants to follow for decades and assess long-term exposure statuses through biennial questionnaires and tumor development. These studies collected tissue specimens of various cancers that had occurred in the cohort participants. For example, we depict colorectal cancer (CRC)/precancer research using the PCIBM on the cohorts (Figure 1). It enabled numerous discoveries of novel etiological links between exposures and CRC incidence plus tumor phenotypes, including one between long-term aspirin use and decreased incidence of PTGS2 protein-positive CRC. For 17 years (as of 2024), no other prospective study has re-tested any of those etiological links. The PCIBM has also enabled the seamless integration of tumor microbiology and immunology into epidemiology. As long-term risk factor exposure appeared to play an important role in early-onset cancer etiology, incident tumor biobanks will contribute to research on the early-onset cancer epidemic. AI-based computational methods will upgrade the PCIBM for worldwide incident tumor biobanks to further improve our understanding of cancer biology/etiology and advance biomedical health sciences.
