Viruses and Cancer

A report on research in progress at Caltech on the viruses that--instead of killing cells--cause them to multiple at a much faster rate.

curious that over 30 pages are allocated to insulinomas and virtually the same to all the other gastrointestinal and pancreatic endocnne tumours.
As I have already hinted, the only major omission that I can find is the limited reference to the use of octreoscan as a diagnostic agent, which in Europe has become an essential part of the modern diagnostic protocol for the investigation of neuroendocrine cancers. However, this can clearly be updated in future editions, as I am sure this will reach a second edition. Furthermore, in a future edition a little more emphasis could be included on the non-surgical therapies of these cancers.
Who is going to buy this book? Reference libraries should consider this a must, and it will certainly be purchased by oncologists, endocrinologists and surgical oncologists with an interest in thyroid and endocrine cancers. However, the general oncologist is probably not going to have this on his shelf. It is also unfortunate that within the next year there is going to be a rival European book published which is likely to cover the same ground. However, it may well be that the volumes are complementary rather than directly rivalling each other.
In conclusion, this is an excellent book which plugs a gap that needed filling. It is a must for the reference library and a must for those rare oncologists who have a particular interest in endocrine malignancies. The story of viruses and cancer is important for two distinct reasons. First, some 15% or more of human cancer incidence is linked with virus infection. Major malignancies in the world, such as cancer of the uterine cervix, primary liver cancer, nasopharyngeal carcinoma (NPC) and several forms of adult T-cell leukaemias and lymphomas, have viruses as an essential component of their aetiology and pathogenesis. Second, oncogenic viruses opened up cancer genetics. Oncogenes were first found in retroviruses long bef6re it was realised that the viruses had purloined cellular genes. Tumour-suppressor proteins were first identified through the study of DNA viruses, as viral proteins such as E6 and E7 of the human papillomaviruses sequester the Rb and p53 proteins, which is the phenotypic equivalent of a genetic knockout. Thus, studies of oncogenic viruses have had a significance far beyond that proportion of cancer actually caused by them.

NS Reed
This volume on viruses and cancer represents papers given at the 51st Symposium of the British Society for General Microbiology. It provides a useful overview of current research into oncogenic viruses. While some chapters are broad reviews, others are focused more narrowly on the authors' own research. I particularly enjoyed David Lane's chapter on tumoursuppressor genes and p53 and Karen Vousden's article on cell transformation by human papillomaviruses. More than 50 pages in the volume are devoted to Epsten-Barr virus (EBV) in relation to B-cell transformation and tumours, whereas only two pages discuss NPC. This is in inverse ratio to the prevalee of these tumours, and reveals the inclinations of EBV specialists: lymphomas are easier to study than carcinomas. Human adenoviruses, perhaps the most potent oncogenc viruses of all when experimentally inoculated into rodents, receive no mention at all, not even in George Klein's introductory article. Perhaps they are deemed uninteresting because they have not been associated with human cancer, and not for want of trying. Yet this very negation is fascinating and puzzling.
In the majority of well-studied viral cancers, the viral genome plays a direct role in cell transformation and the maintenance of the malignant phenotype. Integrated or episomal viral genes are found in the tumour cell clones. However, it is also becoming increasingly evident that viruses can predispose to cancer indirectly. In this volume Ian Weller illustrates HIV-related cancers with respect to immune deficiency, while Jan Butel and colleagues discuss hver cancer is relation to hepatitis B and C viruses, where chronic liver damage may promote the emergence of the premalignant clones of liver cells not infected by the virus. Viral carcinogenesis may be direct or indirect, but in both cases it can be prevented by immunisation against viral infection in the first place. Here, vaccination is discussed only in relation to human and bovine papillomaviruses and feline leukaemia virus. However, successful intervention studies against hepatitis B virus are already under way in West Africa, and time will tell if this leads to a significant drop in the incidence of liver cancer. There appears to be a synergistic relationship between virus and dietary carcinogens briefly mentioned by Butel et al. for liver cancer and by Saveria Campo for bovine papillomavirus type 4. A more thorough discussion of co-factors in viral oncogenesis and the prospects for prevention would not have come amiss. Nonetheless, for those intrested in the relation of viruses to cancer, this volume provides a useful introduction to the field. This is the third volume in the series of reviews highlighting growth areas in haematological oncology aimed at both clinicians and research workers. The editors set themselves a very difficult task in accepting such a wide remit and by and large achieve a lot. However, such review texts become rather piecemeal and lack the continuity of a monograph or text committed to a specific topic. Consequently, in this volume there is something for everyone but no topic is fully covered, e.g. the epidemiology and viral aetiology of lymphomas are included, but these are not put into the context of clinical manifestation, immunophenotyping or pathology. For the clinician reviewing a topic or for the hard-pressed examination candidate multiple texts are thus required, while the researcher is more likely to find value in the bibliographies and hence the original papers.
Those critical comments are applicable to all such texts and must not detract from the well-written individual contributions, all by respected authorities in their field. Cartwright and McNally's Epidemiology of Non-Hodgkin's Lymphomas is an excellent reference source, although so many large tables make it difficult for the reader. I was confused by the comment that 'no clear geographical associations emerged' in childhood NHL and then the discussion of Burkitt's lymphoma, for which there is a very characteristic geographical variation. There were many other intriguing items of interest which, as the authors suggest, do really warrant further research. Onions has produced a very fine and comprehensive overview of the viral aetiology of lymphoid malignancies, as has Myrtle Gordon on the stromal microenvironment. The stroma is a complex area to study but represents a real growing point of haematological research, and this is a timely review of the subject. The back-to-back chapters on myeloma therapy are especially helpful to the practitioner deciding on therapy for an individual patient, and in particular Diana Sampson's final recommendations are clear and very useful. Peripheral blood stem cell transplantation is very much the flavour of the month, for obvious reasons, but with the available growth factors changing so rapidly texts such as this one inevitably become