European journal of cancer. Part B, Oral oncology最新文献

Multiple tumours of the salivary glands are very rare and their combinations according to histological classification of the tumours, localisation and origin (origin in independent topographical areas or in the same tissue) are diverse.

The following two categories can be distinguished: common occurrence of multiple salivary gland tumours with identical histology, or with different histology. In either group the tumours can be unilateral or bilateral, synchronous or metachronous. The most common multiple tumours with an identical histology are Warthin tumours and pleomorphic adenomas. Bilateral occurrence has been observed especially in oncocytomas, acinic cell carcinomas and basal cell adenomas. In the group of multiple tumours with differing histology, Warthin tumours and pleomorphic adenomas show a number of combinations with other adenomas or carcinomas of the salivary glands. Notable also is the simultaneous occurrence of salivary gland tumours with other oral tumours or extraglandular tumours, especially thyroid carcinomas and breast carcinomas.

Multiple salivary gland tumours must be distinguished by nomenclature from tumours with biphasic differentiation and hybrid tumours. Tumours with biphasic differentiation are defined as regular, recurring mixtures of two cellular components in the same tumour and have a corresponding term in the tumour classification. Hybrid tumours are very rare and are composed of two different tumour entities within the same topographical area. Each of the tumour entities conforms with an exactly defined tumour category.

All the oral cancer patients registered at the Regional Cancer Centre, Trivandrum, during January to July 1995 were subjected to detailed pedigree analysis. This revealed that oral cancer tends to aggregate in families. Like other familial cancers, a family history of oral cancer was associated mostly with an early age of onset of the disease. Family members without habits such as tobacco chewing, smoking or alcohol consumption were also affected. These observations prompt us to suggest the probable inheritance of an oral cancer susceptibility gene in these families. The familial aggregation, mostly site-specific, with an autosomal dominant mode of inheritance, was observed in 0.94% of the total oral cancers. This necessitates the need to undertake studies to elucidate the molecular lesions responsible for oral cancer susceptibility in families.

Acidic glycoconjugates represent the major non-fibrous macromolecular components that form the extracellular and cell-associated matrices of all animal tissues. The constituent molecules are principally structural glycoproteins and proteoglycans. While their protein component is determined by gene pools, it is the polyanionic (acidic) nature of the polysaccharides, determined by their degrees of carboxylation and sulphation, which confers both functional and diagnostic status on these molecules. Sulphated glycoconjugates in the basal laminae have been reported to play a role in tumour invasion and metastasis. In this study, we used cationic colloidal gold together with transmission electron microscopic methods to compare the expression of acidic glyconconjugates in the basal lamina of both normal rat tongue mucosa and experimentally induced oral carcinomas. Results indicated that heparan sulphate rich glycoconjugates were predominant and were mostly confined to the lamina lucida of the basal lamina in normal oral mucosa. Conversely, observation of basal laminae associated with induced carcinomas showed less intense and more widely dispersed gold labelling for heparan sulphate. The observed differences in gold labelling may reflect modified metabolism of sulphated glycoconjugates or result from the action of degradative enzymes in the induced tumours.

The expression of glycoconjugates specific to Jack fruit lectin (JFL) and peanut agglutinin (PNA) in various clinicopathological stages of tumour progression in the oral mucosa were studied. These included various clinical forms of dysplastic and non-dysplastic oral leucoplakias, carcinomas, normal keratinising (gingiva) and non-keratinising (buccal mucosa) epithelia. It was seen that the binding patterns of PNA and JFL in the epithelial cells of various types of oral lesions were more or less similar. Normal non-keratinising epithelium showed mild membrane staining only in the spinal layers, while normal keratinising epithelium showed a moderate membrane staining and mild cytoplasmic staining in all layers. Moderate membrane and mild cytoplasmic staining were observed in leucoplakias, irrespective of various clinical or histological types. In carcinomas, the intensity of lectin binding was high, particularly in the membrane of differentiated cells. Correlation analysis of the binding pattern of PNA and JFL showed significant correlation in the membrane and cytoplasm of all layers with histological stages of tumour progression. The present study thus showed that PNA and JFL may be used as cytochemical probes in differentiating malignancy from benign lesions of the oral mucosa.

Metastatic tumours to the oral region are uncommon. There are more published cases of jawbone métastases than in oral soft tissues. The most common primary sources of metastatic tumours to the oral region are the breast, lung, kidney, bone and colon. The breast is the most common primary site for tumours metastasising to the jawbones, whereas the lung is the most common source for métastases to the oral soft tissues. In the jawbones, the common location of the metastatic lesions is the mandible, with the molar area being the most frequent involved site. In the oral soft tissues, the attached gingiva is the most common affected site followed by the tongue. In nearly 30% of cases, the metastatic lesion in the oral region is the first indication of an undiscovered malignancy at a distant site. The biological basis of the metastatic process is discussed.

Twenty-one patients with squamous cell carcinoma of the nasal columella and vestibule were treated at the Mount Vernon Centre for Cancer Treatment between March 1986 and January 1994. Tumours ranged from 15 to 55 mm in maximum dimension (median 25 mm). All patients were treated with radical intent with continuous hyperfractionated accelerated radiotherapy (CHART). This group was analysed with respect to tumour control, tumour cell kinetics and radiation-induced morbidity at a median time to last follow-up of 40 months. Particular attention was paid to the detailed evaluation of late radiation changes. Patients who were still alive were assessed as to the satisfaction with the cosmesis of their treated nose. Four patients had relapse of disease either at the primary site alone (2), in neck nodes (1) or in both regions (1). One patient was successfully salvaged with surgery. Cell kinetic studies showed that cancers at this site may have potential for rapid cellular repopulation similar to cancers developing at other head and neck sites. CHART was well tolerated by patients. Late skin changes were remarkedly slight (despite full skin dose) and overall cosmesis excellent with this radiotherapy schedule.

A retrospective study on 422 nasopharyngeal carcinoma (NPC) patients with cervical nodal metastases treated between 1984 and 1987 was performed. 169 received neoadjuvant chemotherapy (CHEMO) with cisplatinum and 5-fluorouracil for two or three courses prior to definitive radiotherapy and 253 were treated by radical radiotherapy alone (NCHEMO). While the primary tumour (T-stage) prognosticators had been comparable between the two groups, CHEMO had significantly more advanced cervical nodal metastases with bulkier nodes and more low-cervical and supraclavicular nodes (P < 0.05) which could account for its overall worse survival, poorer regional tumour control and a trend towards worse systemic tumour control. The worse regional control in CHEMO for Ho's N1 could be the result of more bulky nodes and more tumours infiltrating the skull base and/or causing cranial nerve(s) palsy. There was no statistical or apparent difference between CHEMO and NCHEMO for the same Ho's overall stages of NPC with comparable nodal and primary tumour characteristics for the clinical endpoints of actuarial survival rate (ASR), disease-free survival rate (DFS), free of local failure survival rate (FLF), and free from distant metastases survival rate (FDM), despite the presence of significantly more fixed nodes and bulky nodes. This suggests a possible beneficial effect of the neoadjuvant chemotherapy. However, multivariate analysis has not shown the administration of the neoadjuvant chemotherapy to be of prognostic significance. Even though the chemotherapy was well tolerated with little toxicity, we recommend against the routine use of neoadjuvant chemotherapy in cervical-node-positive NPC outside the context of a prospective randomised clinical trial.

A classification and staging system for oral leukoplakia is proposed based on the recently revised definition of this premalignant lesion. The initial experiences of this system are described on the basis of 100 patients with oral leukoplakia. The new classification and staging system seems very suitable for characterizing groups of patients with oral leukoplakia. Whether this system is also valuable with regard to guidelines for management of these patients has still to be proven.