Dietmar Öfner

Methylation changes in faecal DNA: a marker for colorectal cancer screening?

DNA methylation is a common molecular alteration in colorectal cancer cells. We report an assessment of faecal DNA from patients with colorectal cancer and controls to determine the feasibility, sensitivity, and specificity of this approach. By use of MethyLight analysis of faecal DNA from three independent sets of patients, we identified SFRP2 methylation as a sensitive single DNA-based marker for identification of colorectal cancer in stool samples (sensitivity 90% [CI 56-100] and specificity 77% [46-95] in the training set [n=23]; sensitivity 77% [46-95] and specificity 77% [46-95] in an independent test set [n=26]). Whether a combination of genetic and epigenetic markers will identify colorectal cancer at an early stage remains to be shown.

Tumor microcirculation and diffusion predict therapy outcome for primary rectal carcinoma

PURPOSE The aim of our study was to correlate perfusion indices and apparent diffusion coefficients with therapy outcome after chemoradiation. METHODS AND MATERIALS In 34 patients with primary rectal carcinoma (cT3) undergoing preoperative chemoradiation, pretherapeutic perfusion indices and apparent diffusion coefficients were obtained by dynamic or diffusion-weighted magnetic resonance imaging. Therapy response was defined if the pathologic observation revealed no invasion into the perirectal fat after chemoradiation. RESULTS In 18 patients, a response and in 16, no response was observed. Statistically significant differences were found for the mean perfusion index (p < 0.001; 7.5 +/- 1.5 mL/min/100 g vs. 10.7 +/- 2.7 mL/min/100 g) and for the intratumoral cumulative fraction of pixels with perfusion-indices > 12 mL/min/100 g (p < 0.001, 3.7 +/- 4.0% vs. 24.7 +/- 17.9%). A three-way ANOVA resulted in significant effects for therapy responder/nonresponder (p < 0.001) and for apparent diffusion coefficient and the individual patients. CONCLUSION Perfusion indices and apparent diffusion coefficients inside the tumor region seem to be of predictive value for therapy outcome of preoperative therapy in patients with primary rectal carcinoma. Higher parameter levels in the nonresponding group could be explained by increased shunt flow or increased angiogenic activity in aggressive tumor cell clusters resulting in reduced nutrients supply and higher fraction of intratumoral necrosis respectively.

Presence and possible significance of immunocytochemically demonstrable metallothionein over-expression in primary invasive ductal carcinoma of the breast

Metallothioneins (MTs) are ubiquitous low-molecular-weight proteins with a high affinity for heavy metal ions such as zinc, copper and cadmium. MT over-expression has been associated with resistance against anticancer drugs. In the present study we investigated 86 cases (45 cases of tumour category pT1 and 41 of category pT2) of routinely fixed and paraffin-embedded primary breast carcinomas immunohistochemically with a monoclonal antibody to an epitope of MT shared by its I and II isoforms. Immunohistochemically demonstrated MT over-expression was found in the invasive components of 7 of 32 pT1 and 17 of 28 pT2 invasive ductal carcinomas, whereas all 26 invasive lobular carcinomas gave weak or negative results. Fourteen of 17 pT2 and 2 of 7 pT1 invasive ductal carcinomas with MT over-expression developed metastases during follow-up with poor prognostic outcome. In contrast only 3 of 11 pT2 and none of the 25 pT1 cases without MT over-expression had a poor clinical course (P < 0.001). It is concluded that MT over-expression is associated with significantly poor prognosis particularly in pT2 invasive ductal breast carcinomas.

Prognosis and life expectancy in chronic liver disease

The aim of the present study was to define prognosis and life expectancy in patients with chronic liver disease of different etiologies and to relate them to an age- and sex-matched normal population. After a follow-up of 15 years, life expectancy of 620 patients with chronic liver disease was retrospectively calculated and compared with an age- and sex-matched normal population. Among patients with cirrhosis, prognosis was dependent upon the Child classification (P=0.001). Patients with alcoholic cirrhosis and fatty liver disease were younger (P=0.01) and had a lower life expectancy than patients with other causes of chronic liver disease (P=0.004). Patients with hepatitis B and hepatitis C cirrhosis showed a comparable prognosis and a significantly lower life expectancy than the age- and sex-matched population. Cryptogenic and autoimmune liver diseases showed a comparable life expectancy but a significantly shorter life expectancy than the normal population. In patients withα1-antitrypsin deficiency-associated cirrhosis, a high viral coinfection rate was found (P=0.01). For patients with noncirrhotic hemochromatosis, prognosis was poorer than that for the age- and sex-matched population. In patients with asymptomatic primary biliary cirrhosis, chronic persistent hepatitis B, andα1-antitrypsin deficiency without cirrhosis, life expectancy was equal to that of the normal population. Prognosis and life expectancy in chronic liver disease depend on stage, cause, and symptoms of chronic liver disease; age; and possibilities of treatment. In patients with hereditary liver disease, additional viral infection or alcohol abuse lead to a significant deterioration of life expectancy. Patients with alcoholic chronic liver disease have the poorest prognosis.

Immunohistochemically demonstrated metallothionein expression in malignant melanoma.

Metallothioneins are ubiquitous proteins with a high affinity for heavy metal ions, e.g. zinc, copper and cadmium. Experimentally, metallothionein over‐expression in cell lines derived from a variety of cancers has been associated with resistance to anticancer drugs and irradiation therapy. Using a monoclonal antibody (E9) to metallothionein we investigated immunoreactive expression in routinely fixed and paraffin‐embedded tissue from 63 cases of malignant melanoma and 13 secondary deposits. Whereas a variety of cells in normal skin showed metallothionein expression, all forms of benign naevi studied were uniformly negative. In contrast 13/30 ‘thin’ (≤1.5 mm; 0.7 ± 0.4). 25 29 ‘thick’ malignant melanoma (> 1.5 mm; 5.5 ± 3.9) and 12/13 metastases were positive. Six patients with thin and 19 with thick melanoma with metallothionein expression died during a mean observation period of 6.4 ± 1.8 and 3.6 ± 2.5 years, respectively, their survival distribution function analyses giving statistically significant results for both the vertical tumour thickness (P < 0.0001) and metallothionein expression (P < 0.0001). These immunohistochemical results, based on routinely processed paraffin‐embedded tissue, suggest that metallothionein expression in malignant melanoma is significantly associated with progressive disease and might therefore be a useful prognostic indicator.

Apolipoprotein(a) phenotype-associated decrease in lipoprotein(a) plasma concentrations after renal transplantation.

High lipoprotein(a) [Lp(a)] plasma concentrations are an independent risk factor for atherosclerosis. In the general population, Lp(a) levels are primarily determined by allelic variation at the apolipoprotein(a) [apo(a)] gene locus. Apo(a) isoforms of various sizes are associated with different Lp(a) concentrations. Patients with end-stage renal disease (ESRD) have elevated plasma concentrations of Lp(a), which are not explained by the size variation at the apo(a) gene locus. To further investigate the origin of the elevated Lp(a) plasma concentrations, we examined Lp(a) concentrations and apo(a) phenotypes in 154 ESRD patients undergoing renal transplantation. In a prospective longitudinal study we observed a rapid normalization of Lp(a) levels from an average concentration of 25.9 +/- 28.7 mg/dL before to 17.9 +/- 25.5 mg/dL 3 weeks after renal transplantation (P < .0001). Only patients with high-molecular-weight phenotypes had a significant decrease in Lp(a) plasma concentrations. This study demonstrates the nongenetic origin of elevated Lp(a) concentrations in ESRD patients, which is obviously caused by the disease. It further confirms a phenotype-associated elevation of Lp(a) concentrations in ESRD.

Deep penetrating dermatofibroma versus dermatofibrosarcoma protuberans. A clinicopathologic comparison

A study of the clinical, histological, and immunohistochemical features of 20 cases of deep penetrating dermatofibroma (DPDF) and eight cases with 14 specimens (eight primary, one reexcision, five secondary tumors) of dermatofibrosarcoma protuberans (DFSP) showed distinct entities. Clinically, DPDF usually appeared as a nodule (-2 cm) of the (lower) limbs, whereas DFSP affected the trunk (shoulder) with irregularly arranged plaques or nodules (>5 cm). Histologically, DFDF showed a regular silhouette with a smooth, nodular (four of 20) or scalloped (16 of 20) lower margin and variable sclerosis (nine of 20): DFSP, irregularly infiltrated fatty tissue in a lacelike/honeycomb (eight of 14), multilayered (three of 14), or mixed pattern (three of 14), but without sclerosis. Immunohistochemically, DPDF was mostly negative with QBEnd 10(CD34; 18 of 20) but positive for factor XIIIa (17 of 20), actin (HHF35; 10 of 20), and metallothionein (MT:12 of 20), DFSP was positive for CD34 (13 of 14), yet with some sparing of central tumor parts, highly cellular tumor nodules, and myxoid areas; factor XIIIa and MT were consistently negative, as was HHF35 in (1 of 14 caes. In a multivariate analysis of histologic and immunohistochemical criteria, the combination of sclerosis and labeling with MT was most valid (p= 0.0001) for diagnosis: all DPDF showed either labeling with MT in “early” (metabolically active) lesions or sclerosis in “late” lesions, not present in DFSP.

Atrophic variants of dermatofibroma and dermatofibrosarcoma protuberans

Dermal atrophy of more than 50% of the locoregional dermis may be the predominant histopathological feature in dermatofibroma and dermatofibrosarcoma protuberans. This may cause diagnostic difficulties. In the present study 26 cases of atrophic dermatofibroma were compared with three cases of atrophic dermatofibrosarcoma protuberans. Clinically, both conditions mostly occurred on the (upper) trunk of females. While atrophic dermatofibroma usually presented as a reddish, umbilicated lesion (0.5–1‐cm), often suspected to be a basal cell carcinoma, atrophic dermatofibrosarcoma protuberans showed irregularly arranged tan‐brown plaques (3–6 cm). Histologically, atrophic dermatofibroma showed a regular silhouette with a smooth nodular (9/26) or scalloped lower margin with an intervening lace‐like pattern of superficial fatty tissue infiltration (17/26) and variable sclerosis; atrophic dermatofibrosarcoma protuberans showed a deep, irregular infiltration of fatty tissue in a lacelike/honeycomb and/ or multilayered pattern, but no sclerosis. Immunohistochemically, atrophic dermatofibroma was mostly negative with QBEnd 10 (CD34; 24/26), variably positive for factor XIIIa (20/26) and metallothionein (11/26). Labelling for factor XIIIa and metallothionein was usually seen in ‘early’ (metabolically active) lesions, while ‘late’ sclerotic ones were negative. In contrast to atrophic dermatofibroma all three atrophic dermatofibrosarcoma protuberans showed a consistently uniform profile: CD34 positive, factor XIIIa and metallothionein negative. Our study delineates atrophic dermatofibroma and atrophic dermatofibrosarcoma protuberans as distinct entities clearly distinguishable from each other by clinicopathologic criteria.

Immunohistochemical distribution of chromogranins A and B and secretogranin II in neuroendocrine tumours of the gastrointestinal tract

The aim of the present study was to investigate immunohistochemically the distribution of chromogranin A, chromogranin B, and secretogranin II in a series of 152 neuroendocrine tumours of the gastrointestinal tract. Tumour tissues from 25 argyrophil gastric carcinoids, 18 gastrin and 5 somatostatin-producing tumours, 4 ‘gangliocytic paragangliomas’, 49 classical argentaffin and 2 L cell appendiceal carcinoids, 27 classical ileal carcinoids, 17 rectal carcinoids, and 5 poorly differentiated neuroendocrine tumours of the stomach and rectum were immunostained with antibodies against chromogranin A, chromogranin B, and secretogranin II. Chromogranin A was the major granin expressed in gastric carcinoids and in serotonin-producing carcinoids of the appendix and the ileum. In contrast, strong chromogranin B and secretogranin II immunoreactivity was found in rectal carcinoids, in which chromogranin A was rarely expressed. Since chromogranin A is a widely used marker for neuroendocrine differentiation, it is of diagnostic importance that some gastrin-producing tumours, ‘gangliocytic paragangliomas’, poorly differentiated neuroendocrine carcinomas, and appendiceal L cell carcinoids completely lacked chromogranin A positivity. It is concluded that the various neuroendocrine tumours of the gastrointestinal tract show distinctly different patterns of granin expression, probably reflecting their histogenetical origin.

Argyrophilic nucleolar organizer region proteins (Ag-NORs) in human brain tumors: relations with grade of malignany and proliferation indices

SummaryProliferation indices and mean number of silver-stained nucleolar organizer region-associated proteins (Ag-NORs) are compared in 65 brain tumors, including 34 gliomas, 8 meningiomas, 17 metastatic tumors, and 6 other tumors. Immunocytochemical investigations include labeling with the monoclonal antibody Ki-67 which identifies the whole growth fraction, and with a monoclonal antibody against bromodeoxyuridine (BrdUrd) which detects cells in the S phase of the cell cycle after in vitro incubation with BrdUrd. When all types of tumors are collectively considered, mean numbers of Ag-NORs did not correlate with Ki-67 and Brd-Urd labeling indices (LIs) and mitotic index. Among tumor subtypes, only meningiomas showed significant correlations between Ag-NOR counts, LIs, and malignancy. Mean number of Ag-NORs did not correlate with proliferation indices and tumor grade in low-grade and high-grade gliomas. However, recurrent high-grade gliomas showed a tendency to higher Ag-NOR counts than primary tumors. This study indicates that counting of Ag-NORs in paraffin sections is of limited value in tumor neuropathology. Correlations found in meningeal tumors should be substantiated in larger series.