Heterogeneic expression of blood group A and H isoantigens in bladder tumors: association with nuclear volume

DNA methylation of the ABO promoter underlies loss of ABO allelic expression in a significant proportion of leukemic patients

Background

Loss of A, B and H antigens from the red blood cells of patients with myeloid malignancies is a frequent occurrence. Previously, we have reported alterations in ABH antigens on the red blood cells of 55% of patients with myeloid malignancies.

Methodology/Principal Findings

To determine the underlying molecular mechanisms of this loss, we assessed ABO allelic expression in 21 patients with ABH antigen loss previously identified by flow cytometric analysis as well as an additional 7 patients detected with ABH antigen changes by serology. When assessing ABO mRNA allelic expression, 6/12 (50%) patients with ABH antigen loss detected by flow cytometry and 5/7 (71%) of the patients with ABH antigen loss detected by serology had a corresponding ABO mRNA allelic loss of expression. We examined the ABO locus for copy number and DNA methylation alterations in 21 patients, 11 with loss of expression of one or both ABO alleles, and 10 patients with no detectable allelic loss of ABO mRNA expression. No loss of heterozygosity (LOH) at the ABO locus was observed in these patients. However in 8/11 (73%) patients with loss of ABO allelic expression, the ABO promoter was methylated compared with 2/10 (20%) of patients with no ABO allelic expression loss (P = 0.03).

Conclusions/Significance

We have found that loss of ABH antigens in patients with hematological malignancies is associated with a corresponding loss of ABO allelic expression in a significant proportion of patients. Loss of ABO allelic expression was strongly associated with DNA methylation of the ABO promoter.

Prognostic criteria in patients with stage D2 prostate cancer. Correlation with mean nuclear volume

BACKGROUND

Histologic grading, especially the Gleason score (GS), is considered to be of value in determining the prognosis of patients with prostate cancer. However, subjective histologic grading is characterized by low reproducibility. Conversely, estimates of mean nuclear volume (MNV), developed by Gunderson and Jensen based on a stereologic technique, is a method with high reproducibility. Furthermore, it has been reported that MNV provides an accurate prognosis of bladder cancer. In this study MNV was compared with two histologic grading methods in determining the prognosis of Stage D2 prostate cancer.

METHODS

A retrospective, prognostic study of 31 patients with Stage D2 prostate cancer treated with transurethral resection of the prostate or needle biopsy between January, 1983, and July, 1994, was performed. Unbiased estimates of MNV were compared with age at the time of diagnosis, histologic grading according to World Health Organization (WHO) classification, and GS on the prognostic value.

RESULTS

Age at the time of diagnosis, WHO classification and GS had no value as prognostic criteria, and only MNV correlated significantly with prognosis of Stage D2 prostate cancer (P = 0.0017).

CONCLUSION

Results of this study indicate that MNV is prognostically superior to morphologic grading of malignancy, such as GS and WHO classification, in Stage D2 prostate cancer.

Quantitative histopathology in the prognostic evaluation of patients with transitional cell carcinoma of the urinary bladder

BACKGROUND

Morphologic grading of malignancy is considered to be of prognostic value in patients with transitional cell carcinomas of the urinary bladder (TCC). This qualitative approach is, however, associated with low reproducibility. Grading of malignancy can be carried out on a reproducible, quantitative scale.

METHODS

A retrospective, prognostic study of 110 patients treated for TCC in clinical Stages Ta-T4 (median follow-up time, 6 years) was performed, evaluating various grading techniques. Unbiased estimates of the volume-weighted mean nuclear volume (nuclear vV), nuclear volume fraction, estimates of nuclear mean profile area (aH(nuc)), nuclear profile density index (NI), and mitotic profile density index (MI) were obtained by stereologic and morphometric techniques.

RESULTS

The T-stage and morphologic grade of malignancy were closely cross-correlated (+0.63 < Kendall tau < +0.71, 2P < 6.7 x 10(-16)). The estimation of nuclear vV was highly efficient, with more than 85% of the associated variation attributable to differences between tumors. A positive significant correlation between estimates of nuclear vV and aH(nuc) was detected (r = +0.79), whereas an inverse correlation was documented between nuclear vV and NI (r = -0.63). Estimates of nuclear volume fraction showed no correlation with nuclear vV. Comparisons between categorical and quantitative data revealed the following: a decrease in averaged estimates of NI for tumors in advanced T-stage and malignancy grade (2P < 0.0008); and nuclear vV and aH(nuc) increased on average, in tumors of high T-stage and malignancy grade. Estimates of MI were also positively correlated with the T-stage and the malignancy grade (+0.42 < Kendall tau < +0.49). Single-factor analyses showed prognostic effect of T-stage, grade of malignancy, and, apart from nuclear volume fraction, all quantitative histopathologic variables with regard to overall survival (2P < 0.03). None of the morphometric and stereologic parameters were of prognostic values with regard to recurrence-free survival (2P > 0.26). Multiple hazards regression analysis (Cox models) revealed that clinical stage of disease was the sole independent prognostic variable. Only estimates of nuclear vV added significant independent prognostic prediction with regard to recurrence-free survival in the 48 patients with Ta tumors (2P = 0.03).

CONCLUSIONS

The results suggested that estimates of nuclear vV are prognostically superior to morphologic grading of malignancy in noninvasive TCC, whereas both morphologically and quantitatively based malignancy grading are without prognostic value in invasive TCC.

Nuclear volume and expression of T-antigen, sialosyl-Tn-antigen, and Tn-antigen in carcinoma of the human bladder. Relation to tumor recurrence and progression

The T-antigen system and the mean nuclear volume have been proposed as risk variables in bladder tumors. This study includes 34 patients with initially noninvasive (Ta) transitional cell carcinomas who experienced different courses of disease. Tissue specimens of primary tumors were analyzed for the expression of T-antigen, Tn-antigen, and sialosyl-Tn-antigen using monoclonal antibodies (MoAb) and the lectin peanut agglutinin (PNA) in an indirect immunoperoxidase method. In addition, the mean nuclear volume was estimated by morphometry. Tissue from 7 of 13 patients (54%) who had invasive disease during a follow-up period of 5 years expressed T-antigen, as defined by MoAb HH8 in the primary tumor, whereas tissue of only 3 of 21 patients who did not have invasive disease expressed the antigen (P less than 0.02). No association was found between tumor progression to invasion and the expression of Tn-antigen or sialosyl-Tn-antigen. Tn-antigen expression was partially lost in invasive tumors (P less than 0.03) when compared with the expression in primary noninvasive tumors. A high mean nuclear volume in tissue specimens of primary tumors correlated with a progression to invasive disease (P less than 0.01). A significantly (P less than 0.003) higher mean nuclear volume was found in tumor areas that were positive for PNA compared with areas that were negative for PNA in primary tumors. A significantly lower mean nuclear volume was found in Tn-antigen-positive invasive Grade 3 tumor areas than in Tn-antigen-negative areas (P less than 0.005). The combined use of T-antigen expression and mean nuclear volume is of potential clinical interest for determining patients who are at high risk of disease progression.

Grading of nuclear pleomorphism in oral carcinomas. Higher prognostic value than stereological assessment of nuclear volume

A more objective and reproducible grading system is needed in order to give better prognostic indicators and thereby offer improved treatment to oral cancer patients. Recently, simple objective stereological techniques for cellular estimates have emerged, of which the estimate of mean nuclear volume has shown a correlation with prognosis for various cancers. We have therefore measured the mean nuclear volume in 44 invasive buccal mucosal squamous cell carcinomas and related it to the survival of patients. The mean nuclear volume did not correlate with prognosis for these patients (p = 0.25). However, the nuclear polymorphism, which is subjective even though it is based on well-described criteria in a histopathological grading system, correlated significantly with prognosis (p = 0.03). These findings indicate that the traditional histopathological evaluation of nuclear polymorphism includes valuable prognostic information.