Suitability of PSA-detected localised prostate cancers for focal therapy: experience from the ProtecT study.

BACKGROUND: Contemporary screening for prostate cancer frequently identifies small volume, low-grade lesions. Some clinicians have advocated focal prostatic ablation as an alternative to more aggressive interventions to manage these lesions. To identify which patients might benefit from focal ablative techniques, we analysed the surgical specimens of a large sample of population-detected men undergoing radical prostatectomy as part of a randomised clinical trial. METHODS: Surgical specimens from 525 men who underwent prostatectomy within the ProtecT study were analysed to determine tumour volume, location and grade. These findings were compared with information available in the biopsy specimen to examine whether focal therapy could be provided appropriately. RESULTS: Solitary cancers were found in prostatectomy specimens from 19% (100 out of 525) of men. In addition, 73 out of 425 (17%) men had multiple cancers with a solitary significant tumour focus. Thus, 173 out of 525 (33%) men had tumours potentially suitable for focal therapy. The majority of these were small, well-differentiated lesions that appeared to be pathologically insignificant (38-66%). Criteria used to select patients for focal prostatic ablation underestimated the cancer's significance in 26% (34 out of 130) of men and resulted in overtreatment in more than half. Only 18% (24 out of 130) of men presumed eligible for focal therapy, actually had significant solitary lesions. CONCLUSION: Focal therapy appears inappropriate for the majority of men presenting with prostate-specific antigen-detected localised prostate cancer. Unifocal prostate cancers suitable for focal ablation are difficult to identify pre-operatively using biopsy alone. Most lesions meeting criteria for focal ablation were either more aggressive than expected or posed little threat of progression.

Somatic allelic deletion of nm23 in human cancer.

Tumor progression to the metastatic phenotype is accompanied in certain cell types by reduced expression of the nm23 gene. We have localized human nm23-H1 to chromosome 17 by somatic cell hybrid analysis. Regional localization in the CEPH database and in situ hybridization is reported. Somatic allelic deletion of nm23-H1 was observed in human breast, renal, colorectal, and lung carcinoma DNA samples, as compared to DNA from matched normal tissues. A homozygous deletion of nm23-H1 was observed in a lymph node metastasis of a colorectal carcinoma, indicating that nm23-H1 can be recessively inactivated. The data identify nm23-H1 as a novel, independent locus for allelic deletion in human cancer, a characteristic shared with previously described suppressor genes.

Elevated levels of MDM-2 and p53 expression are associated with high grade non-Hodgkin's lymphomas.

The role of p53 in the evolution of non-Hodgkin's lymphomas (NHL) is unclear. Mutations of the p53 gene appear to be relatively uncommon but stabilized p53 protein, as detected by immunohistochemistry, has indicated a more frequent involvement of p53. As dysfunction of p53 protein has also been suggested to occur after overexpression of the mdm-2 protein, we have therefore investigated a series of non-malignant hyperplastic reactive lymphoid tissues and NHL to examine whether the levels of expression of MDM-2 correlated to positivity of p53 protein staining. Northern blot analysis of MDM-2 expression was compared to glucose-6-phosphate dehydrogenase (G6PD) expression by densitometry to quantify the relative levels of MDM-2 expression. Consistent low levels of MDM-2 expression were observed in non-malignant lymphoid tissue and in low grade NHL, however, 13/15 high grade NHL exhibited a 2-15-fold increase in MDM-2 expression. Interestingly similar elevations in p53 mRNA expression were also observed in 6/15 high grade NHL. Positive staining of the p53 protein did not, however, correlate with elevated mRNA levels of either MDM-2 or p53. The significance of these observations is discussed.

Investigation of the effect of BB-94 (batimastat) on the colonization potential of human lymphoma cells in SCID mice.

We have assessed the effectiveness of the metalloproteinase inhibitor BB-94 (batimastat) in reducing the colonization potential of the human Burkitt lymphoma Namalwa cell line. In this study Namalwa cells were injected intraperitoneally into SCID mice and their spread to the spleen, liver and lung studied over a 3 week period. The human cells were detected in the mouse tissues by polymerase chain reaction (PCR) amplification of a human alu repeat sequence. Comparison of BB-94-treated animals with an untreated control group provided no evidence for a significant reduction in the colonization of mouse tissues by the human lymphoma cells in the presence of the drug. Tumour growth, after subcutaneous injection of the Namalwa cells into SCID mice, was similarly unaffected by BB-94. The significance of these results is discussed.

Gestational choriocarcinoma of the ovary diagnosed by analysis of tumour DNA.

Gestational choriocarcinoma of the ovary is a rare form of malignancy which can be difficult to distinguish from primary ovarian choriocarcinoma. The ability to make such a diagnosis could, however, have important implications for therapy. We report here a case of choriocarcinoma whose origins were difficult to determine and which behaved clinically more like a primary rather than a gestational choriocarcinoma. We have analysed DNA from this tumour by using polymerase chain reaction (PCR) amplification of a range of polymorphic alleles and have demonstrated that the tumour was in fact gestational. Furthermore, the lack of chromosome Y sequences and the presence of heterozygosity of the spouse's alleles, indicated that this tumour arose as a result of dispermic fertilisation of an empty ovum by sperm carrying the X chromosome.

2D-gel analysis of proteins in chronic lymphocytic leukemia cells and normal B-lymphocytes.

Protein synthesis was analysed in leukaemic cells from 10 chronic lymphocytic leukaemia (CLL) patients by 2D-gel electrophoresis of 14C-labelled proteins. There appeared to be only minor differences between each of the CLL samples, but there was evidence that the level of expression of a few of the proteins might have correlated to the stage of the disease. Comparison of the CLL samples to populations of normal B-lymphocytes demonstrated marked differences in protein synthesis between the leukaemic and non-malignant cells. We subsequently used the fluorescence activated cell sorter (FACs) to separate CD5+ from CD5- B-lymphocytes, but observed that the protein synthesis exhibited by these two populations was essentially the same, and both were very different to that observed in CLL cells. The significance of these observations with respect to the origins of CLL is discussed.

Peripheral T cell lymphoma: The Sheffield Lymphoma Group experience (1977-2001).

Peripheral T-cell lymphomas (PTCL) account for approximately 10% of all non-Hodgkin's lymphomas. The aim of this retrospective study was to analyse the presentation, management, outcome and significant prognostic factors in a large series of patients with PTCL. It includes 104 consecutive patients who presented to the Sheffield Lymphoma Group between 1977 and 2001. Clinical parameters were recorded for each subgroup. End points were response to treatment and survival. Survival analysis was used to assess the prognostic value of the variables. PTCL not otherwise specified contributed 52% of cases followed by anaplastic large cell lymphoma with 17% and angiocentric type with 13% of cases. The overall complete remission (CR) of the series was 59%. Stage at diagnosis affected response to treatment with 81% of cases in stage 1 and 2 achieving CR compared to 43% in stages 3 and 4 (p60 years (p<0.05), high grade histology (p<0.001), presence of B symptoms (p<0.005), nodal presentation (p<0.005) and advanced stage at diagnosis (p<0.001). Histological sub-type did not significantly correlate to outcome. In conclusion whilst a number of prognostic indicators can assist in determining the outcome in PTCL, these lymphomas are complex and often follow an unpredictable course. In order to make the best clinical decisions in individual cases, more clinical study is required.

Localised extranodal non-Hodgkin's lymphoma of the gastrointestinal tract: Sheffield Lymphoma Group experience (1989-1998).

Extranodal non-Hodgkin's lymphoma (NHL) of the gastrointestinal tract accounts for about one third of all extranodal NHL. We retrospectively reviewed the clinical and histopathologic records of 71 patients with stage IE and IIE primary gastrointestinal NHL referred to the Sheffield Lymphoma Group (SLG) from 1989 to 1998. Cross-referencing with the Hospital Histopathology Department database revealed that only two-thirds of all cases were seen by the Group. The most common primary site was the stomach (45 patients, 63% of all cases), followed by the small intestine (16, 23%) and large intestine (9, 13%). The median age of patients was 62 years; the majority of patients presented with stage I (61%) and/or grade (65%) NHL. Mucosa-associated lymphoid tissue (MALT) lymphomas were the largest histologic subtype seen (57%), with 87% of these arising from the stomach; next most frequent was the diffuse large B-cell subtype (21% of all cases) most frequently arising from the intestine (60%). For treatment of gastric MALT lymphoma, a combined approach (surgery followed by chemotherapy, antihelicobacter therapy followed by chemotherapy) was favoured (22 cases). Five-year and 10-year overall survivals were 52% and 45% respectively. Knowledge of the Revised European American Lymphoma classification and the Helicobacter pylori/MALT association has influenced treatment approaches over the 10-year study period. For small intestinal lymphoma, surgery (with or without chemotherapy) gave 5- and 10-year survivals of 60%. Overall survival of patients with primary gastrointestinal lymphoma managed by the SLG is similar to that reported from other large series.

Immunohistological demonstration of progesterone receptor in breast carcinomas: correlation with radioligand binding assays and oestrogen receptor immunohistology.

The validity of determining the progesterone receptor status of breast carcinomas with a monoclonal antibody was investigated by comparison with data from a radioligand binding assay on adjacent cryostat sections of 103 tumours. Significant nuclear staining for progesterone receptor was observed in 37 (36%) of the tumours studied and this showed a close correlation with the results of radioligand binding assays for progesterone receptor. In three progesterone receptor positive tumours there was an apparent paradoxical absence of oestrogen receptor; progesterone receptor normally depends on the presence of oestrogen receptor, but these rare tumours may be essentially progesterone receptor positive. It is concluded that this monoclonal antibody is an appropriate reagent for use in the immunohistological determination of progesterone receptor status of breast carcinomas; that it advantageously identifies both the occupied and unoccupied receptor sites; and that it provides information about tumour cell heterogeneity with respect to receptor status.

Obstructive uropathy associated with myelomonocytic infiltration of the prostate.

A 72 year old man was diagnosed with chronic myelomonocytic leukaemia (CMML) according to the FAB group classification. He presented with symptoms of anaemia, urinary frequency, hesitancy, and nocturia. He was later admitted with acute urinary retention and acute renal failure, which resolved with treatment. A transurethral resection of the prostate was performed. Histological examination showed fibromuscular hyperplasia with dense infiltration by myelomonocytes which stained positively with chloroacetate esterase; immunohistochemical staining was positive for lysozyme, CD43, CD45, and CD68. Following treatment with oral etoposide he transformed to acute myeloid leukaemia and eventually died. Myelomonocytic infiltration of the prostate has not been reported before. This case extends the spectrum of disease previously recognised in CMML.

Demand management in urine cytology: a single cytospin slide is sufficient.

AIMS: Current practice in most laboratories stipulates the preparation of duplicate slides for the analysis of urine cytology specimens. This study evaluates whether the duplicate slide is necessary. METHODS: Cytospin diagnosis was assessed in three ways. First, all urine cytology preparations from a single month in 1998 were reviewed; the two slides for each case were reported separately and then the two reports on each case were examined for disparity. Second, the slides from all urine cytospin cases indexed as "suspicious" or "malignant" in 1998 were reviewed similarly. Third, 48 cytospin slides from 24 cases were divided into two randomised groups, which were reported and the two reports compared. Finally, the frequency of repeat specimen collection in cases that were deemed inadequate for diagnosis was also assessed. RESULTS: The cases from a single month (n = 129) were representative of the annual workload and showed no discrepancies of the type: suspicious or malignant/other. Of the 60 suspicious or malignant cases from 1998, there was no disparity in 50. The 10 cases with disparity were all suspicious on one slide and degenerate on the other. In the 24 randomised cases, there was no disparity in 21. The remainder were reported as suspicious or malignant/inadequate (that is, degenerate or acellular). After a report of inadequate for diagnosis, repeat samples were received in only 15% of cases. CONCLUSIONS: Using a single cytospin preparation causes minimal loss of clinically relevant information, but saves substantial resources (approximately 40%/case). A diagnosis of inadequate should prompt the collection of a repeat sample if the service is being used sensibly.

Soft tissue, pelvic, and urinary bladder leiomyosarcoma as second neoplasm following hereditary retinoblastoma.

This report describes two patients who developed leiomyosarcomas, one involving the subcutaneous tissue of the thigh and the pelvic soft tissues and the other the urinary bladder, following hereditary retinoblastoma 36 and 38 years earlier, respectively. There is an increased risk of the development of sarcoma, most commonly osteosarcoma, as a second malignancy following hereditary retinoblastoma. Leiomyosarcoma developing as a second malignancy has rarely been reported and most have occurred in the field of previous radiotherapy. The literature on leiomyosarcoma occurring as a second neoplasm following retinoblastoma is reviewed.

Cytogenetic analysis of a United Kingdom series of non-Hodgkins lymphomas.

We describe cytogenetic analyses of cells derived from 40 non-Hodgkins lymphoma (NHL) node biopsies, 23 of which were from patients who had not been treated before biopsy. We noted that the chromosomes most frequently gained were X (32%), 12 (27%), and 3 (24%). Monosomies were much less common; loss of chromosome 13 (13.5%) was most frequent. Structural abnormalities primarily involved chromosomes 14 (70%), 1 (40.5%), 18 (38%), 6 (35%), and 17 (22%). Low-and high-grade disease showed similar patterns of structural changes; however, a markedly greater number of chromosome gains were associated with low-grade disease. Biopsy samples from patients who had previously been treated showed an increased frequency of structural abnormalities, as well as a significantly larger number of chromosome gains. The importance of these observations, particularly with regard to possible oncogene involvement in lymphoma evolution, is discussed.

Identification of different gene expression patterns in low and high grade non-Hodgkin's lymphomas by differential display.

We have compared the patterns of gene expression in non-Hodgkin's lymphoma (NHL) biopsy samples from patients with either low grade or high grade disease, by the polymerase chain reaction (PCR) based technique of differential display. By using a combination of 30 primer pairs we estimate that we were able to survey over 3,000 genes expressed in these tissues. In this study we compared a group of three low grade follicular centre lymphomas with a group of two high grade diffuse large cell lymphomas and scored only those PCR products that were represented in all samples of each group. In doing so we were able to avoid many of the problems associated with the occurence of false PCR-positives. 139 differences were then scored as representing genes which may be differentially expressed during the transformation from low to high grade disease. However, as many of these might simply reflect changing populations of cells, we focused on only those genes which appeared to be expressed exclusively in either low grade or high grade disease. We have identified 14 such genes, of which 10 were low grade specific and 4 were high grade specific. This approach therefore appears to offer a systematic method for the identification and characterisation of differentially expressed genes, which are characteristic of different NHL sub-types.

Cytogenetic analysis of non Hodgkin's lymphomas by ratio-painting and comparative genomic hybridization reveals unsuspected chromosomal abnormalities.

Cytogenetic analysis of cancer cells has proven to be a powerful tool in understanding malignant evolution and in providing clinically useful markers. In recent years the advent of new fluorescence in-situ hybridization (FISH) methods such as ratio-painting and comparative genomic hybridization (CGH) have enabled much more accurate karyotypes of malignant cells to be detected. In this study, we have examined the chromosomes present in malignant cells from a series of 6 low grade follicular centre and 2 high grade diffuse large cell non-Hodgkin's lymphomas (NHL) using conventional G-banding. In all cases chromosome abnormalities were observed, including the presence of marker chromosomes in six cases. The NHL cells were then subjected to the FISH method of ratio-painting. This provided a more accurate understanding of the origins of derivative chromosomes and identified the origins of all of the marker chromosomes. It also revealed hitherto unsuspected abnormalities. For example, in one case four abnormal chromosomes were demonstrated to contain material from chromosome 8, which had not been previously suspected from G-banding. Regions of amplification and deletion on the chromosomes were also investigated by CGH, which identified further unsuspected chromosomal abnormalities. For example, in case L124, trisomy of chromosome 7 was confirmed by CGH, but an unsuspected amplification of 3(p12) was also revealed. These approaches demonstrate the power of FISH technology in providing a more precise analysis of malignant cell chromosomes, and in doing so have produced comprehensive karyotypes of the NHL under study.

Investigation of the expression of housekeeping genes in non-Hodgkin's lymphoma.

Studies of quantitative changes in gene expression in malignant cells have often used housekeeping genes as controls against which the level of expression of a gene under study could be compared. We have now examined whether the expression of the most commonly used of these housekeeping genes can be regarded as reliable controls for gene expression studies in non-Hodgkin's lymphoma (NHL). We have used Northern blot analysis to compare the levels of expression of beta-actin, alpha-tubulin, beta 2-microglobulin and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) to that of ribosomal RNA. These studies demonstrated that whereas there was a reasonable correlation between the relative levels of rRNA and housekeeping gene expression in reactive hyperplastic nodes, there were major differences in the relative levels of expression of the housekeeping genes in both low and high grade lymphomas; only GAPDH showed any degree of consistency. These observations indicated that housekeeping gene expression was not a reliable control for estimating changes in the level of expression of other genes in NHL, and instead suggested that 18S or 28S rRNA expression offered a more accurate method of RNA quantitation.

Investigation of BCL-2 gene rearrangements in a United Kingdom series of low and high grade non-Hodgkin's lymphomas.

Rearrangements of the BCL-2 gene are thought to be the most frequent genetic changes that occur in non-Hodgkin's lymphomas (NHL), and are particularly associated with follicular low grade disease. Wide variations in the frequency of these rearrangements have, however, been reported in studies of NHL series from different parts of the world. We were therefore interested to determine the frequency of BCL-2 gene rearrangements in the different grades of NHL from a U.K. series. We have done this by using a combination of Southern blot hybridization and polymerase chain reaction (PCR) analysis. The frequencies of rearrangements in our series were 9/20 (45%) in low grade follicular NHL, 1/8 (12.5%) in low grade lymphocytic and 5/19 (26%) in high grade NHL. However, estimation of the high grade value was complicated by the fact that a number of the high grade samples in our series were from patients who had transformed from low grade follicular disease. If the patients were ranked on the basis of whether they had a history of low grade follicular disease then the frequency of BCL-2 rearrangement remained the same 13/29 (45%), but was only 1/10 (10%) in high grade NHL with no history of follicular disease. The former figure was intermediate between those reported for the USA and Japan series, but the latter high grade figure was the lowest reported from any series. The significance of BCL-2 rearrangements in the evolution of both low and high grade NHL is discussed.

MDR-1 expression in non-Hodgkin's lymphomas is unrelated to treatment intensity or response to therapy.

Over-expression of the MDR-1 gene, which codes for P-glycoprotein, is thought to be an important mechanism in the drug resistance exhibited by many tumours. A number of chemotherapeutic agents which induce MDR-1 expression are also components of combination chemotherapies that are used in the treatment of high grade non-Hodgkin's lymphomas (NHL). We have therefore examined expression of MDR-1 in a series of NHL by Northern blot analysis as well as investigated the localization of P-glycoprotein by immunohistochemistry. The series included 11 hyperplastic reactive nodes and tonsils, 17 low grade NHL and 15 high grade NHL. The levels of MDR-1 mRNA were quantified by scanning densitometry and comparison with levels of glucose-6-phosphate dehydrogenase (G6PD). The MDR-1 mRNA was observed in both non-malignant and NHL tissues. Immunohistochemical staining revealed that expression of MDR-1 mRNA in reactive nodes was related to the presence of P-glycoprotein in lymphocytes, however, P-glycoprotein was apparent in both the reactive lymphocytes and tumour cells in the NHL samples. Elevated mRNA levels (2-3 fold increase) were observed in some low grade and high grade NHL relative to those observed in reactive lymphoid tissue. There appeared to be little correlation, however, between expression of the MDR-1 gene and either treatment intensity or response to therapy. The drug resistance that is often encountered in NHL patients is therefore likely to involve mechanisms other than over-expression of P-glycoprotein.

Investigation of the RB-1 tumour suppressor gene in a United Kingdom series of non-Hodgkin's lymphomas.

We have investigated the RB-1 tumour suppressor genes in a series of 20 non-Hodgkin's lymphomas (NHL). Polymerase chain reaction (PCR) amplification of polymorphic alleles indicated that there was evidence of allelic imbalance around 13q14, the site of the RB-1 gene, in at least 5 NHL. Immunohistochemical analysis of the RB-1 protein demonstrated wide variations in the percentage of cells exhibiting positive staining, but these usually correlated with differences in the proliferation index as indicated by staining of Ki67. Only 3/35 NHL exhibited significantly fewer cells expressing RB-1 protein than expressed Ki167. A comprehensive analysis of the mutation status of RB-1 in 20 NHL was carried out using PCR based strategies involving single strand conformational polymorphism (SSCP) gels. Most of the protein coding region was studied by analysing cDNA derived from its mRNA and the remaining 5'-end of the coding region investigated by analysing exon I of the gene. We also examined the promoter region of the gene. In none of the 20 NHL investigated were we able to identify a mutation: the only abnormal migrating fragment observed proved to be a polymorphism in exon I of the gene in 5 NHL. In one other case we detected instability at an intron repeat sequence, which had occurred during progression of the disease, but again no mutation of the protein coding region was found. The low levels of RB-1 protein expression that we had observed in a few of our NHL therefore did not appear to be due to mutation of the gene. These data suggest that mutation of RB-1 is not a common event in the evolution of NHL, but that there may be another, as yet unidentified, tumour suppressor gene near the RB-1 locus which is associated with NHL.

Analysis of the colonization of unirradiated and irradiated SCID mice by human lymphoma and non-malignant lymphoid cells.

We have evaluated the severe combined immunodeficient (SCID) mouse as an in-vivo model for the study of non-Hodgkin's lymphomas (NHL). Characterization of the immune system of the animals in our SCID mouse colony was carried out to assess the numbers of lymphoid cells present, to determine natural killer (NK) cell activity as a function of age and to examine the histology of the lymphoid organs. In this study four human NHL established cell lines (Daudi, Namalwa, U937, MC116), lymphoma cells from four fresh NHL biopsies and normal peripheral blood mononuclear cells (PBMC) and bone marrow cells were investigated, after intraperitoneal injection into the mice. The presence of the human NHL cells in the peritoneum and spleen was assessed by FACS analysis. The colonization potential was investigated in a range of tissues by polymerase chain reaction (PCR) amplification of human repetitive sequences. These studies revealed clear differences in the abilities of the NHL cell types to colonize the SCID mice. Namalwa, Daudi and U937 cells demonstrated the highest efficiency of colonization and readily formed tumours, whereas MC116, the NHL biopsy cell populations and the non-malignant lymphoid cells showed little ability to survive and colonize other tissues in the SCID mice. Whole body irradiation of the SCID mice appeared to improve the survival of human PBMC, NHL biopsy cells and MC116 cells in the peritoneum, but had little effect on their colonization potential. The significance of these studies is discussed.