Jörg Hemmer

Prognostic Value of Graph Theory-Based Tissue Architecture Analysis in Carcinomas of the Tongue

Several studies on oral squamous cell carcinomas (OSCC) suggest that the clinical value of traditional histologic grading is limited both by poor reproducibility and by low prognostic impact. However, the prognostic potential of a strictly quantitative and highly reproducible assessment of the tissue architecture in OSCC has not been evaluated. Using image analysis, in 193 cases of T1-2 (Stage I-II) OSCC we retrospectively investigated the prognostic impact of two graph theory-derived structural features: the average Delaunay Edge Length (DEL_av) and the average homogeneity of the Ulam Tree (ELH_av). Both structural features were derived from subgraphs of the Voronoi Diagram. The geometric centers of the cell nuclei were computed, generating a two-dimensional swarm of point-like seeds from which graphs could be constructed. The impact on survival of the computed values of ELH_av and DEL_av was estimated by the method of Kaplan and Meier, with relapse-free survival and overall survival as end-points. The prognostic values of DEL_av and ELH_av as computed for the invasive front, the superficial part of the carcinoma, the total carcinoma, and the normal-appearing oral mucosa were compared. For DEL_av, significant prognostic information was found in the invasive front (p < 0.001). No significant prognostic information was found in superficial part of the carcinoma (p = 0.34), in the carcinoma as a whole (p = 0.35), or in the normal-appearing mucosa (p = 0.27). For ELH_av, significant prognostic information was found in the invasive front (p = 0.01) and, surprisingly, in putatively normal mucosa (p = 0.03). No significant prognostic information was found in superficial parts of the carcinoma (p = 0.34) or in the total carcinoma (p = 0.11). In conclusion, strictly quantitative assessment of tissue architecture in the invasive front of OSCC yields highly prognostic information.

The behaviour of neurogenic tumours of the maxillofacial region

In 37 patients with neurogenic tumours of the maxillofacial region, epidemiology, clinical, sonographical and computer tomographical findings as well as the results of fine needle aspiration cytology (FNAC), histopathological evaluation of biopsies and flow cytometric determination of DNA ploidy, were analyzed in order to detect characteristics distinguishing the behaviour of the neoplasm prior to resection. Simultaneous histopathological and flow cytometric evaluation of biopsies is recommended to avoid the danger of mistaking ancient schwannomas for malignancies and vice versa. FNAC proved to be unreliable in these cases. The retromaxillary/pterygomandibular region appeared to be the most likely site for malignant schwannoma. Von Recklinghausens neurofibromatosis in the patient or in their family should lead to immediate investigation of any mass developing in the vicinity of the facial or trigeminal nerves.

Comparison of DNA flow cytometry and fluorescence in situ hybridization with a set of 10 chromosome-specific DNA probes in four head and neck carcinomas

Four squamous cell carcinomas of the oral cavity were simultaneously analysed by DNA flow cytometry (FCM) and fluorescence in situ hybridization (FISH) with alpha-telomeric DNA probes specific for chromosomes 1, 2, 3, 6, 7, 8, 10, 12, 17, and X. Nuclei with 2 hybridization signals for most chromosomes were in agreement with flow cytometric DNA content in a diploid tumor, but a monosomy 8 for half of the cells indicated a tumor clone with an aberrant chromosome 8. Aberrations of virtually all chromosomes were found in 3 aneuploid tumors. Comparing the relative numbers of disomal and aneusomal nuclei with the corresponding proportions of DNA diploid and aneuploid sample cells provided evidence that the flow cytometrically diploid cell population of an aneuploid tumor consisted of both karyotypically normal and abnormal cells. Although there was a high degree of concordance between aberrant DNA content and magnitude of chromosomal aberration, discrepancies between both methods suggested a notable clonal heterogeneity in aneuploid tumor cell populations. These results demonstrate that a simultaneous application of DNA flow cytometry contributes to broaden the utility of interphase cytogenetics.

Dose dependence of the cytokinetic and cytotoxic effects of epirubicin in vitro.

SummaryCHO cells were exposed in vitro for 1 h to concentrations of 0.1–20 μg/ml of the cytostatic drug epirubicin. Population growth, survival fractions, cell-cycle-phase distribution, and BrdU incorporation were analyzed. A fraction of the cells showed a transitory cytostatic reaction at 1 μg/ml, and >99% of the cells were killed at 10 μg/ml. The survival curve was biphasic with a steep slope at concentrations of up to 5 μg/ml. Approximately 0.1% of the cells were resistant to higher concentrations of epirubicin. Bivariate DNA/BrdU flow cytometry revealed that the sensitive cells were blocked and probably killed in the G2M phase of the cell cycle.

Anticancer Drug Action Assessed by Serial DNA Flow Cytometry during Induction Chemotherapy in Oral Squamous Cell Carcinoma: Impacts on the Development of Individualized Treatment Strategies

Biopsy specimens from 53 advanced oral squamous cell carcinomas were taken before and after intra-arterial induction chemotherapy and analyzed by DNA flow cytometry. The 5-year overall survival rate was 90% in patients with diploid carcinomas in contrast to only 18% of those with pretherapeutically aneuploid tumors. A clear decrease of aneuploid cell numbers during chemotherapy indicated that DNA flow cytometry substantially allows monitoring of cytotoxic effects in vivo. Even if the immediate response to chemotherapy was significantly better in carcinomas with a complete disappearance of aneuploid tumor cells during treatment than in cases with persisting aberrant cells, the overall survival rate was nearly identical in both groups.

Monitoring of intra-arterial treatment with epirubicin and cisplatin in oral carcinoma by DNA flow cytometry

Twenty-two patients with squamous cell carcinoma of the oral cavity were treated intra-arterially with epirubicin and cisplatin. Biopsies were taken before, during, and after treatment and analysed by DNA flow cytometry. Clinical response to therapy was better in the diploid group as well as in previously aneuploid tumors which showed complete disappearance of the abnormal clone in the course of treatment. Poor reduction of tumor volume corresponded with persistence of aneuploid cells.

Endoreduplication in conjunction with tumor progression in an aneuploid laryngeal squamous cell carcinoma

We report the case of a 58-year-old man who presented with a squamous cell carcinoma pT1a G2 of the left vocal cord. Six months after histologically verified complete resection, the patient experienced an endolaryngeal and extralaryngeal local recurrence pT4 pN2b G2. We applied DNA flow cytometry (FCM) and comparative genomic hybridization (CGH) on both primary and recurrent tumor. The primary tumor and the endolaryngeal compartment of the relapse was an aneuploid cell clone with a FCM DNA index of 1.42 and 1.44, respectively. The extralaryngeal compartment showed a shift featuring a DNA index of 2.78. In the primary tumor and in both compartments of the recurrence there was an identical pattern of complex chromosomal imbalances as detected in CGH (CGH karyotype: rev ish enh [8q24.2-q24.3, 10q26.1-q26.3, 11q24-q25, 12q24.2-q23.33,X], dim [4q, 13q14.3-q31], amp[1p36.1-p36.2]). Hence, the recurrence was not associated with further gains and losses of chromosomal material. However, in the anterior part of the recurrence, the aneuploid tumor cell genome had completely doubled, obviously due to endoreduplication. Immunohistochemical analysis of several cell-cycle regulators revealed altered expression of checkpoint proteins, pointing to a complex disturbance in cell-cycle regulation.