As illustrated by prostate cancer screening provides an opportunity for early intervention and treatment. However the screening test needs to detect patients with cancer with a low rate of false positives and at a stage which can be treated. Recently the concept of treating patients at high risk of developing breast cancer or suffering a recurrence has been highlighted by the western studies with Nolvadex (tamoxifen). Thus roundtable discussion (held in Tokyo) discussed the different strategies in Japan compared to US & Europe for screening & early intervention/prevention of cancer for breast, prostate, bladder, liver, lung, gynaecological & GI cancers. The range of strategies for cancer screening, how it is funded, whether it is appropriately targeted and whether there is any evidence for a beneficial effect on morbidity or mortality & future prospects for improved sensitivity through new methodology or markers were discussed. Although the relative rates of cancer vary between Japan & the West, the same factors seem to influence cancer development & the data on intervention were seen to be valid. The changing patterns of cancer in Japan suggest a clear opportunity for reducing, the incidence of cancer through lifestyle modification. For some cancers, e.g. cervical & bladder where there is a clear link between abnormal cytology & development cancer true prevention is already practiced. In other cases, preventive treatment is limited by the efficacy of available therapies. As far as drug treatment is concerned, funding of healthcare in Japan does not recognise the concept of prevention although there is, in practice, no barrier to the use of interventions where there is a clear link between biochemical/histological markers & development of cancer.