Thomas K. Zirbes

Lymph Node Size and Metastatic Infiltration in Colon Cancer

Background: Detection of metastatic lymph nodes in colon cancer is essential for determining stage and adjuvant treatment modalities. Lymph node size has been used as one possible criterion for nodal metastasis. Although enlarged regional lymph nodes are generally interpreted as metastases, few data are available that correlate lymph node size with metastatic infiltration in colon cancer.Methods: In a prospective morphometric study, the regional lymph nodes from 30 colon specimens from consecutive patients with primary colon cancer were analyzed. The lymph nodes were counted and the largest diameter of each lymph node was measured and analyzed for metastatic involvement by histological examination.Results: A total of 698 lymph nodes were present in the 30 specimens examined for this study. A mean number of 23 (range, 19–39) lymph nodes was found in each specimen. Of these nodes, 566 (81%) were tumor-free and 132 (19%) contained metastases. The mean diameter of the lymph nodes free of metastases was 3.9 mm, whereas those infiltrated by metastases averaged 5.9 mm in diameter (P< 0.0001). Of the tumor-free lymph nodes, 528 (93%) measured < 5 mm in diameter, whereas 70 (53%) lymph nodes containing metastases measured < 5 mm in diameter.Conclusions: Lymph node size is not a reliable indicator for lymph node metastasis in colon cancer. A careful histological search for small lymph node metastasis in the specimen should be undertaken to avoid false-negative node staging.

Correlation of the immunohistochemical reactivity of mucin peptide cores MUC1 and MUC2 with the histopathological subtype and prognosis of gastric carcinomas.

The expression of MUC1 and MUC2 mucin peptide core antigens in gastric carcinomas was studied by immunohistochemistry to determine correlations with TNM stage and histo‐pathological classifications as well as a possible prognostic impact. Paraffin‐embedded specimens from 128 gastric carcinomas with a minimal follow‐up of 5 years were immunostained. In addition to a polyclonal antiserum generated against polymorphic epithelial mucin (MUC1) from human milk, 2 monoclonal antibodies (MAbs), HMFG2 (anti‐MUC1) and 4F1 (anti‐MUC2), were applied. Reactivity of carcinomas was correlated with the classifications of the UICC (TNM), WHO and Laurén. Correlations with overall survival were analyzed using the Kaplan and Meier product limit method. MUC1 immunoreactivity was associated with an advanced pTNM stage. The demonstration of both mucin species (MUC1, MUC2) displayed a statistically significant correlation with tubular/papillary vs. signet‐ring cell differentiation as well as with intestinal‐type vs. diffuse‐type of tumor growth according to Laurén. In particular, MUC2 was only rarely detectable in signet‐ring cell and diffuse‐type tumors. MUC1 correlated with poor prognosis in all cases and the subgroup of stage I tumors. According to the histopathological classifications, a similar result was observed in signet‐ring cell and diffuse‐type carcinomas. In contrast, MUC2 reactivity was associated with a favourable prognosis of intestinal‐type carcinomas. In the non‐neoplastic gastric mucosa, both peptide cores were recognized in the superficial epithelium, whereas parietal cells contained only MUC1, and intestinal metaplasia almost exclusively MUC2 antigens.

Prognostic impact of p21/waf1/cip1 in colorectal cancer

In addition to the tumor suppressor gene p53, Cyclin Dependent Kinases (CDK) are well known to influence the cell cycle in normal human tissues and various neoplasias as well. The purpose of our present study was to evaluate the expression of the CDK‐inhibitor p21/waf1/cip1 in colorectal cancer with special emphasis on the prognostic impact. Between 1985 and 1991, 294 patients (median age, 65 years) underwent surgical operative therapy for colorectal cancer. Formalin‐fixed and paraffin‐embedded tumor specimens were investigated. For immunohistochemistry the Catalysed Reporter Deposition (CARD) technique was performed. The survival propability was calculated and possible prognostic risk factors were tested using multivariate analysis. The p21/waf1/cip1 staining pattern was positive in 197 (67%) specimens and negative in 97 (33%) samples. No significant correlation could been calculated between p21/waf1/cip1 expression and other variables such as age, sex, WHO‐Classification, localisation, grading, TNM‐classification or UICC‐stage. Patients with a positive staining reaction had a significantly better survival (p < 0.0052). Moreover, p21/waf1/cip1 was shown to be an independent prognostic parameter by multivariate analysis (p < 0.022). In contrast with these findings, the p53 tumor status had no impact on survival. P21/waf1/cip1 appears to be an independent prognostic parameter in colorectal cancer and is associated with a favorable survival. This feature may be related to a cell cycle arrest in the G1 phase induced by p21/waf1/cip1, resulting in lower tumor cell proliferative activity. Int. J. Cancer (Pred. Oncol.) 89:14–18, 2000.

Comparative evaluation of the prognostic value of MUC1, MUC2, sialyl-Lewisa and sialyl-Lewisx antigens in colorectal adenocarcinoma

Comparative evaluation of the prognostic value of MUC1, MUC2, sialyl‐Lewisa and sialyl‐Lewisx antigens in colorectal adenocarcinoma

Increased galectin-3 expression in gastric cancer: correlations with histopathological subtypes, galactosylated antigens and tumor cell proliferation.

Galectin-3 represents an endogenous galactoside-binding lectin which may be involved in tumor cell adhesion and proliferation. In order to evaluate its biological significance in human gastric cancer, we investigated its expression in the stomach of a large series of patients (n = 193) by immunohistochemical staining with the monoclonal antibody Mac-2. Compared to normal tissues, primary gastric adenocarcinomas showed a slight increase in galectin-3 expression. However, there was no correlation of membrane-bound and cytoplasmic galectin-3 with histopathological differentiation parameters (according to the WHO and Laurén classifications) or tumor progression (as documented by pTNM staging). Nuclear galectin-3 reactivity was significantly stronger in diffuse-type cancer compared to the intestinal-type tumors. Galectin-3 binds to terminal GalNAcα(1–3) bound to polylactosamine chains and related glycotopes. Therefore, the strong coexpression of membrane/cytoplasmic galectin-3 with Griffonia simplicifolia agglutinin I (GSA I) binding sites (Galα1–3Gal-, GalNAcα–) on carcinoma cells seems to be interesting. On the other hand, nuclear galectin-3 immunoreactivity did not correlate with the incidence of Ki-67-positive tumor cells. A prognostic value of galectin-3 regarding patient survival could not be established.

Histopathological Subtypes and Prognosis of Gastric Cancer Are Correlated with the Expression of Mucin-Associated Sialylated Antigens: Sialosyl-Lewisa, Sialosyl-Lewisx and Sialosyl-Tn

The expression of three sialylated mucin-associated antigens – sialosyl-Lewisa (SLEA), sialosyl-Lewisx (SLEX) and sialosyl-Tn (STN) – and their correlation with the TNM stage, histopathological growth pattern and prognosis was investigated in a series of 127 gastric carcinomas. Various classification systems (pTNM, WHO and Laurén) did not display any correlation with an expression of the sialomucin antigens under study. SLEA reactivity was strongly associated with an unfavorable outcome of the total population, whereas SLEX and STN did not exert such an impact. However, in the subgroups of pTNM stage I as well as pN0 patients, SLEA and SLEX reactivity of the tumors was associated with a worse prognosis. In the subgroup of diffuse-type cancers as defined according to Laurén’s classification, the expression of all three antigens indicated a worsening of the prognosis.

Expression of Bcl-2 and Bcl-xL in Cutaneous and Bone Marrow Lesions of Mastocytosis

Mastocytosis is a rare disease characterized by accumulation of mast cells in tissues. To investigate whether an altered regulation of mast cell apoptosis might be involved in the pathogenesis of mastocytosis, expression of the apoptosis-preventing molecules bcl-2 and bcl-xL was studied by immunohistochemistry in skin and bone marrow lesions of mastocytosis patients. In addition, reverse transcription-polymerase chain reaction was used to investigate levels of bcl-2 and bcl-xL mRNA in cutaneous mastocytosis lesions. Since activating mutations of c-kit are known to be associated with some forms of mastocytosis, human mast cell cultures were also stimulated via c-kit and the expression of bcl-2 and bcl-xL was assessed by immunoblotting. In patients with mastocytosis, the expression of bcl-2 protein but not bcl-xL in cutaneous mast cells was significantly enhanced, compared to healthy controls. Evaluating different subgroups of adult and pediatric mastocytosis patients, all groups were found to express significantly increased levels of bcl-2 protein, and none of the patient groups was found to overexpress bcl-xL, with the exception of solitary mastocytomas that showed a tendency for up-regulated bcl-xL protein. Furthermore, the expression of bcl-2 mRNA was significantly enhanced in cutaneous lesions of adult and pediatric patients, while bcl-xL mRNA levels were only slightly increased in pediatric, but not in adult patients with mastocytosis. In contrast to the skin lesions, bone marrow infiltrates of patients with systemic mastocytosis showed only low or absent immunoreactivity for bcl-2, but marked expression of bcl-xL. In vitro, stimulation of two different mast cell culture systems by activation of c-kit resulted in up-regulation of bcl-2 and also in an increase of bcl-xL, although less pronounced. Thus, overexpression of bcl-2 and bcl-xL leading to prolonged survival of mast cells may contribute to the pathogenesis of mastocytosis. Our findings may help to develop new strategies for the treatment of this disease.

Apoptosis and expression of bcl-2 protein are inverse factors influencing tumour cell turnover in primary carcinoid tumours of the lung.

This study evaluates potential regulating factors in primary pulmonary carcinoid tumours, 16 typical and four atypical samples, with special emphasis on apoptosis and the bcl‐2 gene family. Furthermore, p53‐related oncogenes were analysed in a search for associated biological parameters.

Differences between Biopsy- or Specimen-related Laurén andWorld Health Organization Classification in Gastric Cancer

The extent of stomach resection in gastric cancer depends on tumor size, tumor location, depth of invasion, and the histological allocation to intestinal or diffuse type according to Laurén. As the latter is based on preoperative findings we performed a retrospective histomorphological study to quantify the differences between biopsy-related and surgical specimen-related Laurén classification. Additionally the World Health Organization (WHO) classification of preoperative endoscopic biopsies and surgical specimens were compared. Preoperative biopsies and resected tumor specimens from 100 patients with primary gastric carcinoma were retrospectively classified according toLaurén and WHO. The reclassification was independently performed by three pathologists who were not aware of the previous diagnoses. In 74% the Laurén classification of pre- and postoperative specimens was identical, whereas 26% of the cases showed a disagreement. Out of 48 tumors with preoperative diagnosis of an intestinal type, 10 tumors (20.8%) exhibited a diffuse growth pattern in the gastrectomy specimens; and 16% of the cases showed a disagreement of the pre- and postoperative histopathological type according to the WHO classification. Preoperative biopsy-related and surgical specimen-related Laurén classification differ in about one-quarter of the cases. Mostly, the preoperative diagnosis of an intestinal tumor type must be corrected into a diffuse or mixed type according to Laurén. Since this may have consequences for the surgical strategy, the extent of surgical resection, rebiopsies, and reconfirmation of an intestinal type should be performed at least in those cases with any doubts of this classification.

Bone Marrow Features and Clinical Findings in Chronic Myeloid Leukemia - A Comparative, Multicenter, Immunohistological and Morphometric Study on 614 Patients

A multicenter, immunohistochemical and morphometric study was performed on diagnostic pretreatment bone marrow biopsies in 614 adult patients with Ph chronic myeloid leukemia (CML) to compare histological features with clinical findings. For identification of mega-karyopoiesis we used the monoclonal antibody CD61 and additionally the PAS reaction to determine the subfraction of atypical micromegakaryocytes and precursors. Labelling of erythroid precursors was carried out by a monoclonal antibody directed against glycophorin C. In order to selectively stain macrophages and their activated subset we applied CD68 and the GSA-I lectin. Density of argyrophilic fibers (reticulin plus collagen) was measured following Gomoris silver impregnation method. In accordance with laboratory data morphological variables revealed a comparable amount of congruence in the various groups of CML patients derived from different sources. In about 26% of patients early (reticulin) to advanced (collagen) fibrosis was detectable. Significant correlations were calculated between the extent of myelofibrosis with splenomegaly, anemia and increasing numbers of erythroblasts and myeloblasts in the peripheral blood count. These features were assumed to indicate more advanced stages of the disease process with ensuing transition into myeloid metaplasia and consequently were associated with an unfavorable prognosis. Significant relationships were revealed between the number of CD61+ megakaryocytes and more important, also their precursor fraction with the degree of fibrosis. This result extends previous experimental findings regarding the impact of immature elements of this cell lineage for the generation of myelofibrosis. The significant association of erythroid precursors with the number of mature (resident) macrophages including their activated GSA-I subset may shed some light on their functional involvement in iron turnover and hemoglobin synthesis. A modified histological classification of predominant bone marrow features is introduced. This simplified synthesis staging system (Cologne Classification) is not only associated with certain sets of laboratory data, but also with different survival patterns.