Gen-iku Kohama

Mode of invasion, bleomycin sensitivity, and clinical course in squamous cell carcinoma of the oral cavity

Forty patients with squamous cell carcinoma of the oral cavity were treated with bleomycin prior to undergoing surgery. The degree of the clinical effect of bleomycin and the postoperative clinical course of each case were estimated from the viewpoint of correlation with the mode of invasion. A strong correlation was found among the mode of invasion, bleomycin sensitivity, and clinical course. A slight effect of bleomycin and poor prognosis existed in the group with a diffuse invasion of mode of invasion, while the greatest effect of bleomycin and good clinical course were achieved in the group with a welldefined tumor‐host borderline.

Multivariate analysis of occult lymph node metastasis as a prognostic indicator for patients with squamous cell carcinoma of the oral cavity

The biologic aggressiveness of squamous cell carcinoma of the oral cavity is reflected in its ability to metastasize to regional cervical lymph nodes. Patients with clinically negative cervical lymph nodes are believed to have a good prognosis; however, the prognosis of patients with lymph node metastasis occurring after excision or radiotherapy of the primary tumor is poor.

Immunohistologic detection of lymphocyte subpopulations infiltrating in human oral cancer with special reference to its clinical significance

Cancer tissues from 30 patients with squamous cell carcinoma of the oral cavity were examined immunohistopathologically as to the responsiveness of the host against its own cancer cells in both biopsy and surgically resected specimens from the same patients. Subpopulations of the infiltrating lymphocytes in cancer tissues were identified on paraffin‐embedded serial sections by a modified indirect immunoperoxidase technique (PAB method) in which it was combined with peroxidase‐antiperoxidase (PAP) complex and avidin‐biotin system with rabbit anti‐human B‐cell, peripheral T‐cell sera. Macrophages were also identified by nonspecific acid esterase staining. T‐cells were predominant over B‐cells in 26 of 30 tissues in biopsy specimens and 23 of 30 in surgically resected specimens with bleomycin treatment. T‐cell infiltration in the peripheral region of the tumor was more prominent than that in the stroma among the cancer nests. T‐cells surrounded the cancer nests, occasionally accumulated around the cancer cells, infiltrated at the marginal part of the cancer nests, and frequently produced perivascular massive accumulations. B‐cells and macrophages, on the other hand, were almost absent or negligible around cancer tissues. The grade of T‐cell infiltration, especially in biopsied specimens, was correlated well to the size of the tumor, and also more marked significantly in patients without cervical lymph node metastasis than in those with lymph node metastasis. Furthermore, there was a significant correlation between the grade of T‐cell infiltration at the peripheral region of the invading cancer mass in initial biopsy specimens and the clinical tumor regression rates with bleomycin treatment, but it did not correlate to the surgically resected specimens. These facts suggest that T‐cells might inhibit the development and spreading of the cancer cells, and that the T‐cell infiltration correlates with the clinical course or prognosis of the oral cancer patients.

Clinical features and management of oral and maxillofacial tumors in children

OBJECTIVE To clarify the characteristics of oral and maxillofacial tumors in children, we carried out a clinical study of such tumors and reviewed the relevant procedures for treatment. Study design. Medical records of 105 patients less than 15 years of age who were treated for oral and maxillofacial tumors during the 20 years between 1976 and 1997 were retrieved and analyzed. RESULTS Of the 105 cases, 102 (97.1%) involved tumors that were benign; only 3 patients (2.9%) had tumors that were malignant. With regard to benign soft tissue tumor, the most common type was hemangioma (25/69; 36.2%), the second most common type was papilloma (19/69; 27.5%), and the most common site was the tongue. With regard to bone tumor, the most common type was odontoma (14/33; 42.4%), the second most common type was ameloblastoma (11/33; 33.3%), and the most common site was the mandible. Most of the odontogenic tumors (25/28; 89.3%) developed in patients more than 6 years of age; these tumors may develop after dental crown formation. In each case of benign soft tissue tumor, resection was performed; 4 of these tumors (2 hemangiomas, 1 lymphangioma, and 1 papilloma) recurred, but after re-resection recurrence has not been found for more than 4 years. In the cases of benign jawbone tumor, resection and enucleation were the procedures principally performed; 3 ameloblastomas recurred after enucleation, but after relatively wide resection for these recurrent tumors there has been no recurrence for more than 17 years. With regard to the ameloblastomas, enucleation with preservation of the periosteum was effective and bone regeneration occurred rapidly. CONCLUSIONS Most oral and maxillofacial tumors in children are benign. In any case of such benign tumor, including ameloblastoma, minimal surgical treatment should be the procedure of first choice.

Maxillofacial fractures sustained during sports

PURPOSE This study investigated the number and type of maxillofacial fractures caused by various athletic activities. PATIENTS AND METHODS The ninety-eight patients were treated between 1977 and 1993, and the type of sport involved, patient age and sex, cause of accident, site of injury, and mode of treatment were evaluated. RESULTS Sports-related maxillofacial fractures accounted for 10.4% of all patients with facial bone fractures. The number of different sports was 19, with the incidence of the fractures being most common in rugby and skiing, followed by baseball and soccer. The ratio of males to females was 5.5:1, and most of the patients were between 10 and 29 years of age. Total restriction from sports activity was between 8 and 12 weeks after initial treatment. CONCLUSION The treatment for sports-related maxillofacial fractures is not different from that for fractures from other causes. However, it is important to establish some standard for deciding the time when it is possible to participate in sports after a fracture.

Enhanced antitumor effect of RGD fiber-modified adenovirus for gene therapy of oral cancer

Current clinical success rates of adenoviral vector (Adv)–based gene therapy of squamous cell carcinoma (SCC) of the head and neck remain unsatisfactory. A major problem with this approach is thought to be related to low Adv transduction efficiency due to weak expression of the adenovirus receptor, coxsackie–adenovirus receptor (CAR), in SCC. To improve the limited infectivity of Adv in oral SCC, we constructed mutated Adv incorporating the integrin-binding motif, RGD, in the HI loop of the fiber knob. The mutated Adv infected target cells through integrins commonly expressed in oral SCC. LacZ marker gene expression after infection with this mutated Adv (Adv-F/RGD) in oral SCC cell lines that showed reduced expression of CAR was approximately 5–10 times higher than that obtained with the parental Adv containing wild-type fiber knob (Adv-F/wt). In an in vitro study, transduction of oral cancer cell lines with Adv-F/RGD expressing human IL-2 (AxCAhIL2-F/RGD) resulted in greater production of cytokine than AxCAhIL2-F/wt infection. In an in vivo therapeutic xenograft model of oral SCC in nude mice, AxCAhIL2-F/RGD demonstrated antitumor effects superior to those of AxCAhIL2-F/wt. These data suggest that exploitation of genetically altered adenovirus vectors with integrin-binding motifs may offer significant improvements in oral SCC gene therapy.

Significance of glutathione S-transferase-π as a tumor marker in patients with oral cancer

Background. The authors analyzed the clinical usefulness of glutathione‐S‐transferase‐π (GST‐π) as a tumor marker in patients with oral cancer.

Expression of Rb, pRb2/p130, p53, and p16 proteins in malignant melanoma of oral mucosa

We previously reported that pRb2/p130 gene, one of the Rb family members, was immunohistochemically abundantly expressed in well-differentiated oral squamous cell carcinomas, whereas in undifferentiated ones the expression was low. Oral malignant melanoma is extremely rare, however the prognosis is poor because it tends to locally invade tissue or metastasize and its biological behavior appears to be different from cutaneous malignant melanoma. The present study dealt with the expression of pRb2/p130, Rb, p53, and p16 in 13 cases of malignant melanoma of oral mucosa as revealed by immunohistochemical staining. The stage classification of the 13 patients was as follows; stage II: eight patients, stage III: three patients, and stage IV: two patients. pRb2/p130 was expressed in only two stage II-cases, neither of which have shown any evidence of recurrence or metastasis for over 14 years. Positive staining for Rb was found in three cases consisting of one stage II-case, one stage III-case, and one stage IV-case. p53 was expressed in two cases, one a stage II and the other a stage IV. Positive staining for p16 was found in seven cases consisting of four stage II-cases, two stage III-cases, and one stage IV-case. pRb2/p130 may be inversely correlated with the malignancy of oral malignant melanoma, but further study is needed.

pRb2/p130 protein expression is correlated with clinicopathologic findings in patients with oral squamous cell carcinoma.

pRb2/p130 is one of the retinoblastoma (Rb) gene family and a suppressor oncogene. Immunohistochemically, the expression of pRb2/p130 was reported to be correlated inversely with the degree of malignancy in lung carcinoma and endometrial carcinoma. In the current study, the correlation between expression of pRb2/p130 and clinicopathologic factors in oral squamous cell carcinoma was investigated.

Variations in the tensor veli palatini muscle with special reference to its origin and insertion.

Objective Previous research on the tensor veli palatini muscle (TVP) has produced conflicting descriptions of its functions and topographical relationships with other orofacial structures. The goal of this study was to describe the morphology of the TVP in a systematic and comprehensive manner. Methods One hundred nineteen sides of 77 human heads from donated cadavers were partially dissected under a binocular microscope. Histological examination of the hard tissue–muscle interfaces was also undertaken. Results There were two adjacent origins of the TVP: the cranial base origin (CB origin) and the auditory tube cartilage origin (AT origin). The CB origin always lay anterior to the AT origin and there was no septum or loose tissue between the two muscular laminae leading from these origins. The muscle fibers converged on a central tendinous plate in the muscle belly, which gradually became a common tendon that rounded the pterygoid hamulus before inserting into the palatine aponeurosis. Notably, secondary insertions were found on the maxillary tuber (33.6%) and/or in the submucosal tissue near the palatoglossal arch (37.8%). Maxillary insertions were almost exclusively associated with an AT origin that was wide as or wider than the CB origin. Histological observations confirmed that the hamulus acted purely as a pulley and suggested that a connecting band to the tensor tympani had no or few functions of an intermediate tendon. Conclusions The TVP appears to act as the dilator tubae and that this function can be maintained by preserving or reconstructing the maxillary insertion during push-back surgery, even if hamulotomy is necessary.