The supplementary diagnostic power of selected immunohistochemical, molecular genetic and infective parameters in epithelial hyperplastic laryngeal lesions

Morphometric analysis of Ki-67 and p16 expression in laryngeal precursor lesions

Laryngeal precursor lesions represent areas of altered epithelium with an increased likelihood for progression to squamous cell carcinoma. The exact molecular mechanisms of malignant transformation of laryngeal mucosa are not completely clear, but are certainly due to deregulation of cell proliferation. To assess the potential value of the p16 and Ki-67 as markers of malignant progression, we undertook a retrospective immunohistochemical and morphometric analysis on biopsy specimens from patients with precancerous lesions in the larynx. Morphometric analysis of samples stained with p16 antibody showed epithelial cell positivity in 29 (100 %) of samples with simple hyperplasia, 31 (100 %) samples with basal/parabasal cell hyperplasia, 23 (88 %) samples with atypical hyperplasia and 20 (95 %) samples with in situ carcinoma. There was a significant difference in percentage of p16-positive cells between samples with simple hyperplasia and samples with in situ carcinoma. Morphometric analysis of samples stained with Ki-67 antibody showed epithelial cell positivity in 27 (93 %) of samples with simple hyperplasia, 30 (97 %) samples with basal/parabasal cell hyperplasia, 26 (100 %) samples with atypical hyperplasia and 18 (86 %) samples with in situ carcinoma. There was a significant difference not only in the percentage of Ki-67-positive cells between samples with simple hyperplasia and samples with in situ carcinoma, but also between samples with simple and basal/parabasal cell hyperplasia. Laryngeal epithelial precursor lesions show significantly opposite patterns in p16 and Ki-67 immunopositivity. Simple hyperplasia on average shows 12 % of Ki-67-positive cells and 46 % of p16-positive cells. In situ carcinoma on average shows 23 % of Ki-67-positive cells and 36 % of p16-positive cells.

[Application of Ljubljana classification in laryngeal precancerous lesions]

The diagnosis and treatment of laryngeal premalignant lesions has been frustrated because of failure to adequately define the histologic changes that may help in prediction of irreversible neoplastic transformation. To assess the grading of laryngeal hyperplastic epithelial lesion it was used a Ljubljana classification of histologic changes. It was done a retrospective study of 104 laryngeal hyperplastic lesions biopsies that were classified according to the Ljubljana classification comprising benign spinous layer augmentation (simple hyperplasia), benign basal and parabasal layer augmentation (abnormal hyperplasia), alteration of epithelial cells towards malignancy (atypical hyperplasia) and carcinoma in situ. One hundred and four biopsies with preneoplastic changes were reevaluated and classified according to Ljubljana classification. It was found 42 cases (40.4%) which showed simple, 38 (36.5%) abnormal, 21 (20.2%) atypical hyperplasia and 3 (2.9%) carcinoma in situ. Three cases of atypical hyperplasia (2.9% of all investigated cases) and one of abnormal (0.96%) progressed to invasive carcinoma during the observation ranging from 5 to 9 years (median 8.1). None of the cases classified as simple hyperplasia showed progression to malignancy. The Ljubljana classification focuses on the important clinical decision involving benign looking hyperplastic lesion that do not require strict follow-up (simple and abnormal hyperplasia); and "risky" epithelium that require close follow-up with repeated histologic assessment to recognize any malignant progression (atypical hyperplasia); and carcinoma in situ that requires fast and complete treatment. We suggest that the Ljubljana classification may give a reliable assessment of laryngeal hyperplastic epithelial lesions and can help in monitoring all those patients.

Divergent Patterns of Allelic Alterations in Premalignant Laryngeal Lesions Indicate Differences in the Impact of Morphological Grading Characteristics

OBJECTIVES

Classic histological grading and molecular genetic analysis of epithelial hyperplastic laryngeal lesions (EHLL) were correlated in an attempt to elucidate, which classic marker reflects best the gradual progression of laryngeal premalignant lesions as determined by an increasing number of molecular genetic aberrations.

METHODS

Thirty-two EHLL were grouped according to four grades of nuclear atypia, four degrees of epithelial maturation and three groups of overall and suprabasal mitotic activity. Overall and suprabasal proliferative activity were measured by MIB-1 immunostaining and staged according to four levels. Allelic imbalance was determined by PCR using 32 microsatellite loci at nine chromosomal arms.

RESULTS

Of the six classic criteria, only progressive mitotic indices correlated with allelic alterations in a remarkable variety of microsatellite markers, especially at chromosome 17p.

CONCLUSION

Using the number of allelic alterations as standard for assessment, this preliminary study gives first evidence that certain morphological criteria could reflect differently the gradual progression of premalignant laryngeal lesions with mitotic index being the most promising marker. Further studies with long-term follow-up are required to prove the predictive value of these criteria in daily practice.

Lymphatic metastasis and nm23H1 genetic instability in Chinese colon cancer patients

AIM: To investigate the pathogenic mechanism of colon cancer at the molecular level and to elucidate the relationship between intercellular adhesion molecule-1 (ICAM-1) and nm23H₁ genes and Chinese patients with colon cancer.

METHODS: DNA was extracted from paraffin-embedded materials. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze MSI and LOH. Expression of ICAM-1 was detected by Envision immuno-histochemistry. Experimental results were analyzed with Leica-Qwin computer imaging techniques and SPSS software of statistics.

RESULTS: ICAM-1 expression of lymphatic endothelium was negative in normal colon and positive in colon cancer respectively. The number of lymphatics positive for ICAM-1 was gradually increased with degree of cancer invasion (P < 0.01). In the group with metastasis of colon cancer, the number of lymphatics positive for ICAM-1 in lymph nodes was more than that in the group with no metastasis (P < 0.01). The frequency of MSI, LOH and nm23H₁ protein was 26.67%, 20.00% and 53.33% in colon cancer, respectively. In TNM staging, MSI (43.75%) and nm23H₁ protein (81.25%) in stages I + II were detected more easily than the corresponding indexes (MSI: 7.14%, P < 0.05 and nm23H₁: 21.43%, P < 0.01) in stages III + IV. By comparison, the frequency of LOH (35.71%) in stages III + IV was more than that of LOH (6.25%, P < 0.05) in stages I + II. LOH exhibited a rising trend along with the Duke’s staging. nm23H₁ protein in the group of tubular adenocarcinoma (60.00%) was higher expressed than that in the group of mucoid adenocarcinoma (20.00%) (P < 0.01), and exhibited a rising trend with the differentiation degrees of tubular adenocarcinoma. nm23H₁ protein in MSI positive group was higher expressed (75%) than that in MSI negative group (45.45%, P < 0.05).

CONCLUSION: The expression of ICAM-1 in lymphatic vessels is beneficial to the judgement of the invasion and metastasis ability of colon cancer and the anti-tumor immunity function, and shows an important clinical significance in predicting lymphatic metastasis of colon cancer. MSI and LOH may separately control the development of sporadic colon cancer with different pathways. LOH mostly arises in the late period of sporadic colon cancer and endows a high aggressive and poor prognostic phenotype. By compassion, MSI may be an early period molecule marker for sporadic colon cancer, enhanced expression of nm23H₁ protein can effectively inhibit colon cancer metastasis and improve prognosis of sporadic colon cancer patients.