Jonathan Said

Abstract We herein present an overview of the upcoming 5 th edition of the World Health Organization Classification of Haematolymphoid Tumours focussing on lymphoid neoplasms. Myeloid and histiocytic neoplasms will be presented in a separate accompanying article. Besides listing the entities of the classification, we highlight and explain changes from the revised 4 th edition. These include reorganization of entities by a hierarchical system as is adopted throughout the 5 th edition of the WHO classification of tumours of all organ systems, modification of nomenclature for some entities, revision of diagnostic criteria or subtypes, deletion of certain entities, and introduction of new entities, as well as inclusion of tumour-like lesions, mesenchymal lesions specific to lymph node and spleen, and germline predisposition syndromes associated with the lymphoid neoplasms.

BACKGROUND: DNA fragments that appeared to belong to an unidentified human herpesvirus were recently found in more than 90 percent of Kaposi's sarcoma lesions associated with the acquired immunodeficiency syndrome (AIDS). These fragments were also found in 6 of 39 tissue samples without Kaposi's sarcoma, including 3 malignant lymphomas, from patients with AIDS, but not in samples from patients without AIDS. METHODS: We examined the DNA of 193 lymphomas from 42 patients with AIDS and 151 patients who did not have AIDS. We searched the DNA for sequences of Kaposi's sarcoma-associated herpesvirus (KSHV) by Southern blot hybridization, the polymerase chain reaction (PCR), or both. The PCR products in the positive samples were sequences and compared with the KSHV sequences in Kaposi's sarcoma tissues from patients with AIDS. RESULTS: KSHV sequences were identified in eight lymphomas in patients infected with the human immunodeficiency virus. All eight, and only these eight, were body-cavity-based lymphomas--that is, they were characterized by pleural, pericardial, or peritoneal lymphomatous effusions. All eight lymphomas also contained the Epstein-Barr viral genome. KSHV sequences were not found in the other 185 lymphomas. KSHV sequences were 40 to 80 times more abundant in the body-cavity-based lymphomas than in the Kaposi's sarcoma lesions. A high degree of conservation of KSHV sequences in Kaposi's sarcoma and in the eight lymphomas suggests the presence of the same agent in both lesions. CONCLUSIONS: The recently discovered KSHV DNA sequences occur in an unusual subgroup of AIDS-related B-cell lymphomas, but not in any other lymphoid neoplasm studied thus far. Our finding strongly suggests that a novel herpesvirus has a pathogenic role in AIDS-related body-cavity-based lymphomas.

Induction of differentiation and apoptosis in cancer cells through ligands of nuclear hormone receptors (NHRs) is a novel and promising approach to cancer therapy. All-trans-retinoic acid (ATRA), an RA receptor-specific NHR ligand, is now used for selective cancers. The NHR, peroxisome proliferator-activated receptor gamma (PPARgamma) is expressed in breast cancer cells. Activation of PPARgamma through a synthetic ligand, troglitazone (TGZ), and other PPARgamma-activators cause inhibition of proliferation and lipid accumulation in cultured breast cancer cells. TGZ (10(-5) M, 4 days) reversibly inhibits clonal growth of MCF7 breast cancer cells and the combination of TGZ (10(-5) M) and ATRA (10(-6) M, 4 days) synergistically and irreversibly inhibits growth and induces apoptosis of MCF7 cells, associated with a dramatic decrease of their bcl-2 protein levels. Similar effects are noted with in vitro cultured breast cancer tissues from patients, but not with normal breast epithelial cells. The observed apoptosis mediated by TGZ and ATRA may be related to the striking down-regulation of bcl-2, because forced over-expression of bcl-2 in MCF7 cells cultured with TGZ and ATRA blocks their cell death. TGZ significantly inhibits MCF7 tumor growth in triple immunodeficient mice. Combined administration of TGZ and ATRA causes prominent apoptosis and fibrosis of these tumors without toxic effects on the mice. Taken together, this combination may provide a novel, nontoxic and selective therapy for human breast cancers.

PURPOSE: To integrate stage, grade, and Eastern Cooperative Oncology Group (ECOG) performance status (PS) into a clinically useful tool capable of stratifying the survival of renal cell carcinoma (RCC) patients. PATIENTS AND METHODS: The medical records of 661 patients undergoing nephrectomy at University of California Los Angeles between 1989 and 1999 were evaluated. Median age was 61 years, male-to-female ratio was 2.2:1, and median follow-up was 37 months. Survival time was the primary end point assessed. Sixty-four possible combinations of stage, grade, and ECOG PS were analyzed and collapsed into distinct groups. The internal validity of the categorized was challenged by a univariate analysis and a multivariate analysis testing for the accountability of each UCLA Integrated Staging System (UISS) category against independent variables shown to have impact on survival. RESULTS: Combining and stratifying 1997 tumor-node-metastasis stage, Fuhrman's grade and ECOG PS resulted in five survival stratification groups designated UISS, and numbered I to V. The projected 2- and 5-year survival for the UISS groups are as follows for the groups: I, 96% and 94%; II, 89% and 67%; III, 66% and 39%; IV, 42% and 23%; and V, 9% and 0%, respectively. UISS accounted for the significant variables in the variate analysis. CONCLUSION: A novel system for staging and predicting survival for RCC integrating clinical variables is offered. UISS is simple to use and is superior to stage alone in differentiating patients' survival. Our data suggests that UISS is an important prognostic tool for counseling patients with various stages of kidney cancer. Further prospective large-scale validation with external data is awaited.

PURPOSE: To create a comprehensive algorithm that can predict postoperative renal cell carcinoma (RCC) patient outcomes and response to therapy. PATIENTS AND METHODS: A prospective cohort study was performed with outcome assessment on the basis of chart review of 814 patients who underwent nephrectomy between 1989 and 2000. At diagnosis, M1 or N1/N2M0 metastatic disease (M) was present in 346 patients (43%), whereas 468 patients had no metastatic disease (NM) (N0M0). On the basis of UCLA Integrated Staging System category and the presence of metastases, patients were divided into low-risk (LR), intermediate-risk (IR), and high-risk (HR) groups. Decision boxes integrating tumor-node-metastasis staging, tumor grade, and performance status were compiled for determining a patient's risk group. RESULTS: NM-LR patients had 91% disease-specific survival at 5 years, lower recurrence rate, and better disease-free survival compared with NM-IR and HR patients. Disease progressed in 50% of NM-HR patients. Disease-specific survival of NM-HR patients who received immunotherapy (IMT) for recurrent disease was similar to that of M-LR patients treated with cytoreductive nephrectomy and adjuvant IMT. Time from recurrence to death for NM-HR patients was inferior to that for M-LR patients. After IMT, approximately 25% of M-LR and 12% of M-IR patients had long-term progression-free survival. M-HR patients did poorly despite IMT. CONCLUSION: Stratifying RCC patients into high-, intermediate-, and low-risk subgroups provides a clinically useful system for predicting outcome and provides a unique tool for risk assignment and outcome analysis. Subclassifying RCC into well-defined risk groups should allow better patient counseling and identification of both NM-HR subgroups that need adjuvant treatment and nonresponders who need alternative therapies.