Morphology, DNA ploidy and HPV in lung cancer and head and neck cancer.

Lung cancer and head and neck cancer have similar genotoxic risk factors. While the vast majority of lung cancers are caused by cigarette smoking alone, smoking together with heavy drinking are the major etiological agents of head and neck cancer. In addition, human papilloma virus (HPV) has been identified as an important causative factor of tonsillar carcinomas. In contrast, chromosomal instability and aneuploidy identifiable by DNA measurement are predominately associated with cancer progression. This selective review summarizes our studies that aimed to gain a better understanding of the biology and pathology of lung cancer and head and neck cancer. In particular, it was attempted (a) to develop a microscopy-based tumor classification system that provides insight into the genetics of cancer cells and in particular their DNA ploidy, (b) to apply this classification system to lung cancer and head and neck cancer and to correlate it with clinicopathological parameters and molecular biomarkers, and (c) to analyze molecular characteristics and in particular the presence of human papilloma virus in lung cancer and head and neck cancer. Therefore, we developed a core classification based on the semi-quantitative assessment of the size and type of tumor cell nuclei and mitoses. It was found that (1) nuclear and mitosis size correlated with the DNA content of the tumor cells, (2) tripolar mitoses were indicative of cancer with near-triploid DNA content, (3) morphological and DNA parameters indicating variability of the cancer genome were associated with poor prognosis of lung cancer patients, (4) HPV-positive head and neck squamous cell carcinomas were characterized by smaller tumor nuclei and reduced DNA amount compared to HPV-negative carcinomas, and (5) HPV is associated with lung cancer in certain geographical regions of the world.

Core classification of head and neck squamous cell carcinomas: correlations between morphology, DNA ploidy and HPV infection.

AIMS: The study intended to reveal whether HPV infection is reflected by nuclear morphology and DNA cytometry parameters in head and neck squamous cell carcinomas (HNSCC). METHODS: In total, 39 HNSCC were selected for reanalysis by histomorphology applying the core classification, DNA cytometry and HPV detection. For the core classification, HE sections were assessed by a score system to evaluate the nuclear size, the mitosis size, their variabilities and the presence of tripolar or tetrapolar mitoses. HPV was analyzed by consensus PCR followed by a hybridization method for virus typing. Static DNA cytometry was applied on single cell suspension focusing particularly on the parameters DNA modal value, DNA index peak, DNA index mean, 2c deviation index and 5c exceeding rate. Statistical analysis was done by T-test or Fisher's exact test. RESULTS: The analysis revealed that HPV positive HNSCC had significantly smaller nuclei than HPV negative cases. Increasing values of the nuclear size and mitosis size were significantly associated with higher indices of the DNA cytometry analysis. CONCLUSIONS: The study confirms that the core classification can provide information on the ploidy of HNSCC and that HPV positive tumors represent a distinct morphological and genetic carcinoma subtype.

Core classification of lung cancer: correlating nuclear size and mitoses with ploidy and clinicopathological parameters.

We attempted to establish a microscopy based tumour characterization providing insight into the genetics of cancer cells and in particular their DNA ploidy. The core classification defined semi-quantitative criteria for scoring the nuclear size ranging from small (core score 1) to giant nuclei (core score 4). By listing all nuclear sizes according to their relative frequencies it provided a measure for core size variability as a correlate of nuclear pleomorphism. Additionally, the mitosis size, their variability and the presence/abundance of tripolar and tetrapolar mitoses were determined. This classification was applied to 155 lung cancer samples from all major histologic types and the results were correlated with the analysis by DNA image cytometry and patient survival. The morphological assessments correlated highly significantly with the DNA ploidy parameters, e.g. small cell lung carcinomas showed the smallest values for nuclear size (mean core score of 1.18) and DNA content (DNA index mean of 2.08c) being highly significantly different from adenocarcinomas (1.95/3.10c), large cell lung carcinoma (2.00/3.26c) and squamous cell carcinoma (2.20/3.42c). In non-small cell lung carcinoma (NSCLC) in general and adenocarcinoma in particular, the core size variability correlated significantly with grading and survival. Furthermore, parameters indicative for chromosomal variability, i.e. 2c deviation index and 5c exceeding rate, were predictors of poor survival in NSCLC patients. As a complement to histologic tumour diagnosis the core classification should help to better stratify cancer subtypes.