Occurrence of Second Oral Potentially Malignant Disorder following Excision of Primary Lesion: A Prospective Study of Cases from a Tertiary Care Centre

Background

Early diagnosis and timely management of potentially malignant oral disorders may prevent malignant transformation and prompt diagnosis of frank malignancies favours better prognosis. The aim of this study was to evaluate the outcome of surgical management of oral potentially malignant disorders of the oral cavity and observe the prevalence of recurrence at the primary site and occurrence of another potentially malignant lesion in these patients.

Methods

The study participants included patients who had undergone clinical oral examination, surgical excision of biopsy-proven cases of dysplastic oral potentially malignant disorders (leukoplakia, erythroplakia, non-healing ulcerative and erosive areas, etc.) who were on routine follow-up as per the standard guidelines. These patients were followed up closely during each monthly follow-up visit for the first year. The patients were then prospectively analysed for any recurrence of lesion. On follow-up visits, detailed clinical oral examination was done to note the prevalence of a new lesion in any oral cavity sub site other than the previous site. If a new lesion was detected, then biopsy followed by surgical excision was followed as per standard guidelines. The follow-up period after the second surgical intervention was 12 months.

Results

Fifty patients with potentially malignant oral disorders underwent surgical excision. The majority of the study subjects were males (39/50) and 41 of them were below 65 years of age. Of 50 patients, 13 (26%) had second oral potentially malignant lesion other than the primary site. The rate of recurrence of the lesions at the primary site was 4% (2/50). Of these patients with recurrence, all had malignant transformation (2/2). Also, patients who were initially diagnosed with moderate dysplasia had a higher chance of recurrence. A second lesion at a site different from the primary lesion was seen in 26% of the cases.

Conclusion

Surgical management of such lesions with one-centimetre oncological margins in all dimensions contrary to the routine five millimetre surgical margins reduces the chance of recurrence.

[Immunotherapy of head and neck cancer. Current developments]

In order to improve the prognosis for patients with head and neck squamous cell cancer (HNSCC) the introduction of new therapeutic strategies is necessary. The concept of immunotherapy has been applied and improved for several years and recent studies have used tumor-specific antigens which facilitates targeted oncologic therapy. However, immunotherapy is hampered by the fact that immunosuppressive mechanisms are pronounced and relevant effector cells are suppressed, especially in patients with HNSCC. Successful immunotherapy could induce an antitumor immune response by restitution of these cell populations. Current anti-tumor immunotherapy includes unspecific immune stimulation, genetic modification of tumor and immune cells, the use of monoclonal antibodies, e.g. cetuximab, adoptive cell transfer and tumor vaccination. In the future, these biologic therapies alone or in combination with conventional therapeutic regimens could present a valuable therapeutic option for HNSCC patients.

Bispecific targeting of EGFR and uPAR in a mouse model of head and neck squamous cell carcinoma

OBJECTIVES

To investigate the efficacy of the bispecific targeted toxin, dEGFATFKDEL, on head and neck carcinoma cell lines in vitro and in vivo.

MATERIALS AND METHODS

A deimmunized bispecific anti-cancer agent was constructed to simultaneously target both the overexpressed EGF receptor on carcinomas and the urokinase receptor (uPAR), that is found on the endothelial cells of the neovasculature within tumors. Flow cytometry assays were performed to determine the level of EGFR expressed on a variety of carcinoma lines. These lines were then tested in tritiated leucine incorporation assays to determine the efficacy of dEGFATFKDEL. Human vein endothelial primary cells were also tested to determine the effectiveness of the ATF portion of the molecule that binds uPAR. Furthermore, mouse studies were performed to determine whether dEGFATFKDEL was effective at inhibiting tumor growth in vivo.

RESULTS

UMSCC-11B and NA, two head and neck squamous cell carcinomas, highly expressed EGFR. Both the carcinoma lines and the human vein endothelial cells were inhibited at sub-nanomolar concentrations by dEGFATFKDEL. The tumor studies showed that the tumors treated with dEGFATFKDEL were significantly inhibited whereas the negative control and untreated tumors progressed. In a separate in vivo study involving another carcinoma line, MDA-MB-231, the effectiveness of dEGFATFKDEL was confirmed. No toxicity was seen at the doses used in either of these mouse studies.

CONCLUSIONS

This bispecific agent is effective in a mouse model of head and neck squamous cell carcinoma. Further study of this reagent for use in the treatment of carcinomas is warranted.