Diagnostic radiography and adult acute myeloid leukaemia: an interview and medical chart review study.

BACKGROUND: Aetiology of acute myeloid leukaemia (AML) is not well understood, perhaps because of its distinct subtypes. High-dose ionising radiation is a known risk factor, but less is known about risk from low-dose exposure such as from diagnostic radiography. METHODS: Subjects were 412 matched case-control pairs. Ten-year subject histories of diagnostic radiography were based on interview and medical records. RESULTS: There was no convincing association between AML risk and ionising radiation exposure from diagnostic imaging procedures, either for AML overall or for any AML subtype. CONCLUSION: The association between diagnostic radiography and AML risk remains uncertain.

Analysis of cyclin-dependent kinase inhibitor expression and methylation patterns in human prostate cancers.

BACKGROUND: Downregulation of genes which negatively control cell cycle progression represents a possible mechanism for prostate tumorigenesis. We examined the expression levels of the p16, p15, p14, and retinoblastoma-susceptibility (RB) genes in primary prostate cancers and human prostate cancer cell lines, and correlated this with the DNA methylation levels of two loci in p16. METHODS: The mRNA levels of p16, p15, and p14 were examined by reverse transcriptase-PCR (RT-PCR). DNA methylation of the p16 5' CpG island was determined by bisulfite genomic sequencing, while methylation of exon 2 shared by the p16 and p14 genes was measured by a quantitative bisulfite-based technique, methylation-sensitive single-nucleotide primer extension (Ms-SNuPE). RB protein levels were assessed by immunohistochemical staining of histologic sections of normal and tumor prostate tissues, using a monoclonal antibody (mAB). RESULTS: Overexpression of p16 mRNA was found in 6/9 (67) of prostate tumors compared to the adjacent normal prostate, whereas elevated p14 and p15 levels were only observed in 2/9 (22) and 1/6 (17) of prostate cases, respectively. There was no statistically significant association of grade (P = 0.18) and stage (P = 1.00) of prostate cancer to the elevated p16 levels in the tumors. The p16 5' CpG island was completely unmethylated in these tissues. In contrast, exon 2 of p16/p14 was methylated in both the tumor and normal adjacent prostates, and was increased in 8/11 (73) of tumors relative to normal tissues. There was no association between p16 overexpression and increased p16/p14 exon 2 methylation in these tumors (P = 1.00). Diminished RB levels in prostate tumors that had upregulated p16 mRNA were found, although absent RB was also detected in tumors without elevated p16 levels. The expression levels of the two genes, RB and p16, were not correlated statistically (P = 0.16). CONCLUSIONS: Our studies show that although the levels of the cell cycle regulators p16, p15, p14, and Rb are altered in prostate cancers, there is no apparent correlation to grade, stage, or any pattern of regulation between the related genes. Exon 2 of p16/p14 is methylated in a majority of prostate tumors compared to the unmethylated upstream 5' region, and may be a potential tumor marker for human prostate cancer.

Progressive increases in de novo methylation of CpG islands in bladder cancer.

We conducted a quantitative analysis of the extent of de novo methylation of four CpG islands in human urinary transitional cell carcinomas of different stages and grades to determine how frequently these CpG islands became methylated in transition cell carcinomas during progression. The CpG islands included exon 5 of PAX6, exon 2 of p16, the 5' end of the deleted in bladder cancer gene, and the 5' end of transmembrane protein containing epidermal growth factor and follistatin domains. These sequences were not methylated in normal urothelial tissues; however, 48 of the 54 tumors examined (89%) showed methylation levels in excess of 20% for at least one of the markers. The number of markers concurrently methylated in individual tumors increased with the stage of the tumor, with several of the more aggressive invasive cancers showing hypermethylation of all four markers compared with the less aggressive invasive cancers. However, considerable methylation defects were present in superficial, preinvasive, papillary tumors. These data demonstrate that 89% of bladder cancers have increased methylation of CpG islands relative to their normal counterparts and suggest the occurrence of a hypermethylator phenotype in which multiple independent CpG islands become concurrently methylated in individual tumors in a process associated with tumor progression.

Quantitative measure of c-abl and p15 methylation in chronic myelogenous leukemia: biological implications.

We used a sensitive, quantitative bisulfite PCR assay, methylation sensitive single nucleotide primer extension (Ms-SNuPE), to measure methylation of the 5' CpG islands of c-abl and p15 in chronic myelogenous leukemia (CML) patients during progression. We found that the Pa promoter of c-abl was methylated in 81% (17/21) of the white blood cells (WBCs) of CML patients, which correlates with previous reports. In contrast, WBCs from healthy donors, acute myelogenous leukemias, acute lymphocytic leukemias, and myelodysplastic syndromes were unmethylated at the c-abl Pa promoter locus. We also observed p15 hypermethylation in 24% (8/34) of CML cases. Methylation of the p15 but not c-abl Pa promoters was associated with CML progression (P = 0.047 vs 0.46), and the two events were independently acquired. We conclude that de novo methylation of c-abl and p15 both occur in CML, and analysis of DNA methylation changes using the bisulfite-based MS-SNuPE assay allows both a sensitive and quantitative assessment of these molecular events compared to other methods currently utilized. (Blood. 2000;95:2990-2992)

Somatic mutations at the SRD5A2 locus encoding prostatic steroid 5alpha-reductase during prostate cancer progression.

Prostate cancer is a serious public health problem in many industrialized countries. Androgens appear to play a critical role in its etiology. Specifically, the active androgen in the prostate, dihydrotestosterone (DHT) which is synthesized by the enzyme steroid 5alpha-reductase from testosterone (T), acts as a mitogen. Hence androgen-deprivation is commonly used during prostate cancer therapy. Two isozymes for steroid 5alpha-reductase have been reported. The type II enzyme is prostate-specific and encoded by the SRD5A2 gene. We have investigated a polymorphic (TA)n dinucleotide repeat in the 3' UTR (untranslated region) of the SRD5A2 gene in 30 matched samples of constitutional ("germline") DNA from peripheral blood lymphocytes and microdissected, pure tumor DNA. We report here 8 LOH (loss of heterozygosity) events and 9 cases of microsatellite instability at this marker. Therefore, almost 57% of the samples examined showed evidence of somatic mutations at the 3' UTR of the SRD5A2 locus. Our data suggest that the SRD5A2 gene may be involved in prostate cancer progression and that this may have relevance for treatment of the disease.

DNA methylation differences associated with tumor tissues identified by genome scanning analysis.

Most investigations on the role of DNA methylation in cancer have focused on epigenetic changes associated with known tumor suppressor genes. This may have led to an underestimation of the number of CpG islands altered by DNA methylation, since it is possible that a subset of unknown genes relevant to cancer development may preferentially be affected by epigenetic rather than genetic means and would not be identified as familial deletions, mutations, or loss of heterozygosity. We used a recently developed screening procedure (methylation-sensitive arbitrarily primed-polymerase chain reaction to scan genomic DNA for CpG islands methylated in white blood cells (WBCs) and in tumor tissues. DNA methylation pattern analysis showed little interindividual differences in the WBCs and normal epithelium (adjacent to colon, bladder, and prostate cancer cells), but with some tissue-specific differences. Cancer cells showed marked methylation changes that varied considerably between different tumors, suggesting variable penetrance of the methylation phenotype in patients. Direct sequencing of 8 of 45 bands altered in these cancers showed that several of them were CpG islands, and 2 of these sequences were identified in GenBank. Surprisingly, three of the bands studied corresponded to transcribed regions of genes. Thus, hypermethylation of CpG islands in cancer cells is not confined to the promoters of growth regulatory genes but is also found in actively transcribed regions.

Early acquisition of homozygous deletions of p16/p19 during squamous cell carcinogenesis and genetic mosaicism in bladder cancer.

We looked for p16/p19 deletion and p16 promoter methylation, as well as loss of 9p21 heterozygosity in pure squamous cell carcinomas (SCC), and in transitional cell carcinomas (TCC) of the bladder with SCC components. Homozygous deletion of p16/p19 was detected in 11 of 21 (52%) cases of pure SCCs and in three of ten (30%) cases of TCC with SCC. Three cases of TCC with SCC had p16/p19 deletion, hypermethylation of the p16 promoter, or LOH on 9p21 only in the SCC components, suggesting that these molecular alterations occurred preferentially in SCC. Interestingly, homozygous deletion of p16/p19 was observed in squamous metaplasia from bladder cancer patients (five of 11, 45%), showing that this change occurred in preneoplastic cells. On the other hand, p16/p19 deletions were not found in squamous metaplasias from non cancerous patients. Hypermethylation of the p16 promoter was observed in two of 14 tumors (14%) and none of seven metaplasias examined. These data suggest that: (a) p16/p19 deletion is associated with early carcinogenesis of SCC of the bladder, and squamous metaplasia of the bladder cancer patient has already sustained genetic changes found in cancer, and (b) genetic mosaicism occurs in cases of TCC with SCC, with the SCC component showing more frequent 9p21 alterations than the TCC component.

p53 protein and gene alterations in pathological stage C prostate carcinoma.

PURPOSE: We determined the extent of p53 immunoreactivity in pathological stage C prostate cancer as well as its correlation to tumor grade, substage, recurrence and proliferation rate. To define better the temporal relationship of p53 nuclear reactivity in prostate cancer p53 immunoreactivity was evaluated in all associated prostatic intraepithelial neoplasia lesions. MATERIALS AND METHODS: Using immunohistochemistry p53 status and proliferation rate were determined in 96 tumors from patients with pathological stage C prostate cancer. Single strand conformational polymorphism in exons 5 to 8 was used in a subset of specimens to assess the association of p53 nuclear accumulation with mutations in the p53 gene. RESULTS: p53 Nuclear reactivity was demonstrated in 10 tumors (10.4%), including 6 with high and 4 with low level nuclear reactivity. Of the tumors 86 (89.6%) had no evidence of p53 immunoreactivity. Each of the 6 tumors with high level p53 reactivity had associated areas of prostatic intraepithelial neoplasia that also showed p53 nuclear reactivity. Furthermore, pathological stage C substage (C1, 2 or 3) was significantly associated with p53 nuclear reactivity (p = 0.04). Proliferation rates were correlated with p53 nuclear reactivity (p = 0.09), while there was no association with tumor grade or recurrence. p53 Gene alterations were noted in 2 of the 3 p53 positive tumors versus no alterations in the p53 gene of 3 p53 negative tumors. CONCLUSIONS: p53 Nuclear accumulation is uncommon in pathological stage C prostate cancer and its presence in premalignant prostatic intraepithelial neoplasia lesions suggests that it may be an early event in a subset of prostate cancers.

Presence of p53 mutations in primary nasopharyngeal carcinoma (NPC) in non-Asians of Los Angeles, California, a low-risk population for NPC.

Mutatins of the p53 tumor suppressor gene are rare in nasopharyngeal carcinoma (NPC) patients who reside in high-risk areas, such as Southeastern China. Among this high-risk group, a pre-existing infection with the EBV and consumption of Cantonese salted fish are closely associated with NPC. We investigated the prevalence of p53 mutations in 28 primary NPC specimens from white (including Hispanic) and African-American patients in Los Angeles, who are at low risk for NPC. Using PCR-based single-strand conformational polymorphism and direct sequencing, we found four mutations (14%) in exons 5-8 of the p53 gene in four patients. All were C-to-T transition mutations: two were present in exon 5-one at codon 142 [CCT (Pro)-->CTT (Leu)] and another at codon 144 [CAG (Gln)-->TAG (stop codon)]. The other two mutations were identified in exon 8: one at codon 273 [CGT (Arg)-->CAT (His)], a CpG site, and one at codon 271, a silent mutation [GAG (Glu)-->GAA (Glu)]. This is the first report investigating the presence of p53 missense mutations in NPC among a low-risk population. Our data indicate that p53 is also an infrequent event among NPC patients at low risk for the disease.

Thrombospondin-1 expression in bladder cancer: association with p53 alterations, tumor angiogenesis, and tumor progression.

BACKGROUND: Thrombospondin-1 (TSP) is a 430-kd glycoprotein that is an important component of the extracellular matrix and is known to be a potent inhibitor of angiogenesis (i.e., formation of new blood vessels) both in vitro and in vivo. Several reports suggest that TSP possesses tumor suppressor function, possibly through its ability to inhibit tumor neovascularization. It has recently been shown that TSP expression is enhanced by the product of the p53 gene (also known as TP53). PURPOSE: We examined the role of TSP expression in tumor recurrence and overall survival in patients with invasive bladder cancer. We also examined the relationship between alterations in p53 protein expression, TSP expression, and tumor angiogenesis. METHODS: Tumors from 163 patients (with a median follow-up of 7.7 years) who underwent radical cystectomy for invasive transitional cell carcinoma of the bladder (63 patients with organ-confined disease and no lymph node involvement, 48 patients with extravesical extension of the disease and no lymph node involvement, and 52 patients with metastasis to regional lymph nodes) were examined for TSP expression by immunohistochemistry, utilizing monoclonal antibody MA-II, which recognizes an epitope in the amino-terminal region of TSP. For each tumor, microvessel density counts and p53 protein expression status (via immunohistochemistry) were also determined. TSP expression was graded as low, moderate, or high without knowledge of clinical outcome, p53 status, and microvessel density count; tumors with moderate and high TSP levels were considered as one group. Groups of patients were compared by Kaplan-Meier product limit estimates of overall survival, the complement of cumulative incidence curves for recurrence-free survival, and the stratified logrank test. Reported P values are two-sided. RESULTS: TSP expression was significantly associated with disease recurrence (P = .009) and overall survival (P = .023). Patients with low TSP expression exhibited increased recurrence rates and decreased overall survival. TSP expression was an independent predictor of disease recurrence (P = .002) and overall survival (P = .01) after stratifying for tumor stage, lymph node status, and histologic grade, but it was not independent of p53 status. TSP expression was significantly associated with p53 expression status (P = .001) and microvessel density counts (P = .001). Tumors with p53 alterations were significantly more likely to demonstrate low TSP expression, and tumors with low TSP expression were significantly more likely to demonstrate high microvessel density counts. Results of an analysis of variance were compatible with the hypothesis that p53 affects tumor angiogenesis by regulating the level of TSP expression. CONCLUSIONS AND IMPLICATIONS: These data support the concept that TSP may possess a tumor-inhibitory function. TSP may act, in part, through the regulation of tumor neovascularity. These results may also provide insight into one mechanism by which p53 exerts its tumor suppressor effects, i.e., through the control of tumor angiogenesis.

Relationship of tumor angiogenesis and nuclear p53 accumulation in invasive bladder cancer.

The purpose of this investigation was to evaluate the relationship between tumor angiogenesis and nuclear p53 accumulation in invasive bladder cancer. We studied 161 patients with invasive transitional cell carcinoma of the bladder who had previously undergone radical cystectomy. Analysis was performed to determine the presence of p53 nuclear accumulation and extent of tumor-associated angiogenesis. p53 status identified a group of patients at high risk for tumor progression (p53-altered tumors), and microvessel density determinations added additional prognostic information by identifying a subset of aggressive tumors within the wild-type p53 subgroup. At 5 years, patients with tumors exhibiting no evidence of p53 alterations and low microvessel counts demonstrated 3% recurrence and 88% survival, compared to 43% recurrence and 59% overall survival for patients with intermediate vessel counts and 61% recurrence and 43% overall survival for patients with the highest vessel counts (P < 0.001 and P = 0.003, respectively). Angiogenesis also provides additional prognostic information to patients with tumors that demonstrate p53 alterations. An association between angiogenesis and p53 status did exist (P = 0. 05); however, 27% of the tumors that showed no evidence of p53 alterations exhibited high microvessel counts, and 26% of tumors with evidence of p53 alterations had low microvessel counts. Tumor-associated angiogenesis adds additional useful prognostic information to that which is obtained from p53 status in patients with invasive transitional cell carcinoma of the bladder. Although an association between p53 status and the degree of angiogenesis was identified, other factors appear to play a role in the regulation of tumor-induced neovasularization.

Contiguous patches of normal human mammary epithelium derived from a single stem cell: implications for breast carcinogenesis.

Tissue clonality can be assessed in females by analyzing the methylation status of polymorphic DNA markers on X-linked genes because extensive de novo methylation of one allele at the preimplantation stage is associated with its permanent inactivation. We applied X chromosome inactivation toward understanding human breast morphogenesis by examining the nonmalignant breast epithelium from two reduction mammaplasties and a mastectomy. We found that entire lobules and large ducts of normal breast tissue have the same X chromosome inactivated, suggesting that they are derived from the same stem cell. The regions of inactivation of a particular X chromosome do not extend over an entire breast, so that ducts and lobules with opposite chromosomes inactivated are present within a single breast. Potential relevance of these observations for malignant transformation is discussed.

High frequency of acute promyelocytic leukemia among Latinos with acute myeloid leukemia.

A high frequency (24%) of acute promyelocytic leukemia (APL) was noted among acute myelocytic leukemia (AML) cases at the Los Angeles County-University of Southern California (LAC-USC) Medical Center, in comparison with the expected frequency of 5% to 15%. Because of the high proportion of Latinos in this center, we questioned if APL is more common in this ethnic group. The proportion of APL among the 80 AML patients of Latino origin was significantly higher (30; 37.5%) when compared with the 62 non-Latinos (4; 6.5%) (P = .00001). In an attempt to verify this finding on a larger group of patients, we analyzed 276 pathologically verified cases of AML in patients aged 30 to 69 years from the entire County of Los Angeles, registered on an ongoing population-based epidemiologic study of AML. APL was more frequent among the 47 Latinos (24.3%) than in the 229 non-Latinos (8.3%) (P = .0075). APL is seen in younger patients with AML, but Latino AML patients also had a higher frequency of APL after accounting for their younger age (age-adjusted odds ratio for APL among Latinos in LAC-USC Medical Center, 9.4 [95% confidence interval (CI) 2.9, 30] P = .0002; among Latinos in the population-based study, 3.0 [95% CI 1.3 to 6.9] P = .01). The different ethnic distribution of AML was found to be due to a higher proportion of APL cases per se, and not to a lower proportion of any other French-American-British subtype (P = .0004). These results, from two different populations of AML patients, indicate that Latinos with AML have a higher likelihood of the APL subtype of disease, which may suggest a genetic predisposition to APL and/or exposure to distinct environmental factor(s).

Angiogenesis in bladder cancer: relationship between microvessel density and tumor prognosis.

BACKGROUND: Tumor stage, histologic grade, and regional lymph node status are currently used to obtain prognostic information about bladder cancers. However, additional prognostic indicators are needed to aid clinicians in selecting patients who would benefit most from specific therapies. A majority of studies assessing the prognostic value of measuring tumor angiogenesis (i.e., measurement of tumor microvessel densities) have found a positive association between increasing microvessel densities and worsening prognosis. PURPOSE: We explored the relationship between established prognostic indicators and the extent of tumor-associated angiogenesis in patients with invasive transitional cell carcinoma (TCC) of the bladder, and we determined whether tumor microvessel density measurement could be used independently to predict bladder tumor behavior. METHODS: Tumor tissue was obtained from 164 patients with invasive primary TCC of the bladder. The extent of tumor-associated angiogenesis in this tissue was evaluated by immunohistochemical methods using HPCA-1, a mouse monoclonal antibody directed against the endothelial cell antigen, CD34. The number of microvessels in a 200x microscopic high-power field (hpf) containing the area of greatest neovascularization within or immediately adjacent to each tumor was determined. The patient population was then divided into three equivalently sized groups, with tumors containing low (< or = 64), intermediate (65-99), or high (> or = 100) numbers of microvessels per hpf. Kaplan-Meier product limit estimates of overall survival and the complement of cumulative incidence curves for recurrence-free survival were plotted. When analyzing survival or recurrence, the logrank test was used to compare groups of patients with and without stratification according to tumor stage. Analysis of variance was used to test for an association between microvessel density and established prognostic variables. Reported P values are from two-sided tests. RESULTS: Microvessel density was significantly associated with disease-free (P < .0001) and overall (P = .0007) survival. The estimated probabilities of recurrence at 5 years were 19% (95% confidence interval [CI] = 8-29), 56% (95% CI = 43-69), and 68% (95% CI = 55-81) for patients with lowest, intermediate, and highest microvessel counts, respectively. Overall survival at 5 years was estimated to be 68% (95% CI = 56-81), 44% (95% CI = 30-57), and 34% (95% CI = 21-47) for the same three patient groups. Microvessel density was associated with disease progression in patients with organ-confined tumors, tumors extending through the bladder wall, and tumors that had spread to regional lymph nodes. Tumor angiogenesis was found to be an independent prognostic indicator when evaluated in the presence of histologic grade, pathologic stage, and regional lymph node status. CONCLUSION: Tumor angiogenesis, as determined by microvessel density measurement, is an independent prognostic indicator for patients with invasive TCC of the bladder.

High frequency of chromosome 9p allelic loss and CDKN2 tumor suppressor gene alterations in squamous cell carcinoma of the bladder.

BACKGROUND: In the Western Hemisphere, 90% of bladder cancers are transitional cell carcinomas, while only 7% are classified as squamous cell carcinomas. In contrast, in Egypt and regions of the Middle East and Africa, where infection by the trematode Schistosoma haematobium is endemic, squamous cell carcinoma is the most common bladder cancer as well as the most common cancer in men. PURPOSE: We planned experiments to understand the genetic defects underlying the development of squamous cell carcinoma and to determine if the morphologically and clinically distinct squamous cell carcinoma and transitional cell carcinoma of the bladder evolve following different genetic alterations. METHODS: Squamous cell carcinoma specimens from high-risk (Egypt, n = 19) and low-risk (Sweden, n = 12) populations were examined for genetic defects known to be involved in transitional cell carcinoma tumorigenesis. Homozygous deletions of the CDKN2 tumor suppressor gene were detected by comparative multiplex polymerase chain reaction. Mutations in the CDKN2 and p53 (also known as TP53) genes were analyzed by single-strand conformation polymorphism and DNA sequencing. Immunohistochemical staining of p53 protein was also performed. Allelic losses in chromosome arms 9p, 9q, and 17p were determined by microsatellite analysis. RESULTS: Homozygous deletions and sequence mutations in the CDKN2 gene were found in 67% (eight of 12) of squamous cell carcinoma specimens, a frequency three times higher than that reported for uncultured transitional cell carcinomas (P = .009). Hemizygous and homozygous deletions in 9p, where CDKN2 resides, were found in 92% (11 of 12) of uncultured squamous cell carcinomas, while only about 39% (35 of 90) of transitional cell carcinomas showed these losses (P = .001). Deletions in 9p with no change in 9q were found in 92% (10 of 11) of squamous cell carcinomas compared with only 10% (11 of 110) of transitional cell carcinomas (P < .001) reported in the literature. The frequency of p53 mutations in squamous cell carcinomas was similar to that reported for invasive transitional cell carcinomas (60%), but the type and position of mutations differed between the two tumor types. Allelic losses in chromosome arm 17p, where the p53 gene resides, were found to be less frequent in squamous cell carcinomas (38%) than in invasive transitional cell carcinomas (60%). CONCLUSIONS: Our results suggest that a putative tumor suppressor gene on 9p, possibly CDKN2, may contribute to squamous cell carcinoma tumorigenesis. Our data on squamous cell carcinoma and previously reported data on transitional cell carcinoma indicate that these two bladder carcinomas differ in their genetic alterations, suggesting that distinct underlying genetic defects may explain, at least in part, the pathological differences between the two tumors of the bladder epithelium. IMPLICATIONS: Development of diagnostic and therapeutic strategies for squamous cell carcinoma of the bladder based on its distinct genetic alterations is warranted.

Mosaicism in human epithelium: macroscopic monoclonal patches cover the urothelium.

Previous studies of chimeric animals and human tissues have shown the clonal nature of organ development, giving clues as to the normal development of organs and also to abnormal developments, such as atheromatous plaques. The clonal nature of bladder cancer in female patients has been demonstrated, but little has been known of the clonal development of the normal urothelium. Using an X chromosome inactivation analysis of cells microdissected from histologic slides from the female human bladder, macroscopic urothelial patches of monoclonality were detected. These patches are about 120 mm.2 in size, contain about 2 x 10(6) cells each and reflect the presence of coherent cellular families composed of stem cells and their differentiated derivatives. The large size of these patches was surprising when compared with previously reported patch sizes in other organ systems. The patches most probably are composed of the descendants of the original founder cells, which would suggest that only 200 to 300 cells participated in the formation of the urothelium. The limited number of stem cells, each giving rise to millions of cells may provide an explanation for the "field defect" that is often referred to in the pathogenesis of bladder cancer, as different cell patches may possess different predispositions to tumorigenesis.

Overstaging of transitional cell carcinoma: clinical significance of lamina propria fat within the urinary bladder.

Staging of transitional cell carcinoma of the bladder relies on an accurate assessment of the depth of tumor invasion within the bladder wall and surrounding structures. Fat adjacent to muscle invasive carcinoma is often interpreted to represent full-thickness invasion of the bladder wall with extension into the perivesical tissues. We present a case report highlighting our finding of significant regions of fat within the lamina propria of the urinary bladder and its clinical importance with respect to the overstaging of carcinoma of the bladder.

Accumulation of nuclear p53 and tumor progression in bladder cancer.

BACKGROUND: We have previously demonstrated a strong association between nuclear accumulation of p53 protein, as determined by immunohistochemical analysis, and mutations in the p53 gene. The purpose of this study was to determine the relation between nuclear accumulation of p53 and tumor progression in transitional-cell carcinoma of the bladder. METHODS: Histologic specimens of transitional-cell carcinoma of the bladder (stages Pa, noninvasive disease, to P4, disease with direct extension into adjacent organs or structures) from 243 patients who were treated by radical cystectomy were examined for the immunohistochemical detection of p53 protein. Nuclear p53 reactivity was then analyzed in relation to time to recurrence and overall survival. RESULTS: The detection of nuclear p53 was significantly associated with an increased risk of recurrence of bladder cancer (P < 0.001) and with decreased overall survival (P < 0.001). In patients with cancer confined to the bladder, the rates of recurrence for stage P1, P2, and P3a tumors that had no detectable nuclear p53 reactivity at five years were 7, 12, and 11 percent, respectively, as compared with 62, 56, and 80 percent, respectively, for tumors that had p53 immunoreactivity. Similar results were obtained when the presence or absence of p53 in the nuclei of the tumor cells was studied in relation to overall survival. In a multivariable analysis stratified according to grade, pathological stage, and lymph-node status, nuclear p53 status was an independent predictor (and in cancer confined to the bladder, the only independent predictor) of recurrence and overall survival (P < 0.001). CONCLUSIONS: In patients with transitional-cell carcinoma confined to the bladder, an accumulation of p53 in the tumor-cell nuclei detected by immunohistochemical methods predicts a significantly increased risk of recurrence and death, independently of tumor grade, stage, and lymph-node status. Patients with transitional-cell carcinoma confirmed to the bladder that demonstrates nuclear p53 reactivity should be considered for protocols of adjuvant treatment.

Mutational spectrum in the p53 gene in bladder tumors from the endemic area of black foot disease in Taiwan.

An elevated risk of bladder cancer has been reported in the endemic region of 'black foot disease' on the southwest coast of Taiwan and may be related to high arsenic levels in artesian well water. Thirteen urothelial tumors from this endemic region were examined for mutations in exons 5-8 of the p53 gene to identify the effects of possible exogenous factors at the DNA level. DNA was extracted from archival tissue after microdissection of tumors and analyzed by PCR-SSCP (polymerase chain reaction-based single strand conformation polymorphism), followed by direct sequencing. Eight cases (62%) showed mutations and 9 of the 10 point mutations observed were transitions. The type and position of the mutations were not significantly different when compared with the spectra of p53 mutations previously reported for transitional cell carcinomas (TCCs). However, two of the mutations were CGC-->CAC base changes at codon 175, a mutational hotspot for many tumor types but previously unreported in TCCs except in cases associated with inflammatory agents. Three of the tumors examined were found to contain double mutations, a relatively rare mutagenic event in human cancers. Our results suggest that the agents responsible for the high risk of bladder cancer in the black foot disease region may operate through an inflammation-based mechanism which increases the amount of DNA damage per mutagenic event.