J Cancer Res Ther. 2013 Apr-Jun;9(2):240-4. doi: 10.4103/0973-1482.113365.

The histological characteristics of clinically normal mucosa adjacent to oral cancer.

Cankovic M, Ilic MP, Vuckovic N, Bokor-Bratic M.

Clinic for Dentistry, Faculty of Medicine, University of Novi Sad, Serbia.

 

ABSTRACT:

BACKGROUND: The ‘field cancerization’ theory tries to explain the risk of local recurrences and development of second primary tumors in oral sqamous cell carcinoma (OSCC) patients. According to this theory it is assumed that clinically normal mucosa adjacent to oral cancer, except molecular, has already developed certain premalignant histopathological changes.

AIMS: The aim of this study was to determine histological characteristics of clinically normal-looking mucosa at different distances from the apparent tumor lesion margins in OSCC patients.

MATERIALS AND METHODS: Normal-appearing oral mucosa biopsy specimens were obtained from 30 new (untreated) oral cancer patients from sites at a distance of 10 mm and 20 mm from the tumor lesion margins and were compared with normal oral mucosa from 30 control patients with benign oral lesions. Results: A total of 21 patients (70%) in the OSCC group demonstrated histological abnormalities under microscopic examination versus 7 (23.3%) control patients (P<0.01). Seventeen oral cancer patients (57%) showed significant difference in incidence and type of histological changes of normal-looking mucosa at a distance of 10 mm from the tumor lesion; 8 (27%) demonstrated reactive changes, 6 (20%) mild dysplasia and 3 (10%) squamous cell carcinoma, compared to histological abnormalities registered in 11 (OSCC) patients (36%) at a distance of 20 mm from the tumor; 10 (33%) displayed reactive changes and 1 (3%) mild dysplasia.

CONCLUSIONS: Histological abnormalities of clinically normal-looking oral mucosa taken at different distances from the tumor lesion indicated the existence of subclinical field change and represent an important parameter during the assessment of the adequacy of surgical resection margins in oral cancer management.

PMID: 23771366

 

Additional text:

It is known that oral squamous cell carcinoma starts with multiple cumulative epigenetic and genetic changes caused by carcinogens (smoking, alcohol, radiation), ultimately leading to clinical visible changes called invasive neoplasm or cancer. The results of this study indicate that clinically normal-looking mucosa adjacent to primary tumor lesion (in the area of about 20 mm) in patients with oral squamous cell carcinoma had suffered certain histomorphologic changes.

 

Figure 1Fig 1.200 reactive changes

Figure 2Fig 2.200a displasia 1

Figure 3Fig 3.100 diplasia 2

Figure 4Fig 4.200 displasia 3

Figure 5

Fig 5.200 carcinoma

 

Figure 1: Microphotograph of oral mucosa with reactive changes (H and E, x 200)

Figure 2: Microphotograph of oral mucosa with dysplastic changes (H and E, x 200a)

Figure 3: Microphotograph of oral mucosa with dysplastic changes (H and E, x 100)

Figure 4: Microphotograph of oral mucosa with dysplastic changes (H and E, x 200)

Figure 5: Microphotograph of oral mucosa with infiltrative squamous cell keratinized carcinoma (H and E, x 200)

 

These histological abnormalities manifested with signs of chronic mucosal irritation, cellular atypia, mild epithelium dysplasia or even squamous cell carcinoma (in 10% of patients), that are caused by the effects of the carcinogens (smoking and alcohol) on the entire oral mucosa. In 40% of patients who both smoke and consume alcohol, histological abnormalities in the form of epithelial dysplasia (precancer) and carcinoma were found, and these changes was no recorded in the group of those who do not smoke and drink alcohol.

Taken together, the results of this work suggest that surgeons during the removal of the tumor must extend resection margins. Therefore it is necessary to give greater importance to field cancerization in oral squamous cell carcinoma patients for the successful treatment and prevention of local recurrences and second primary tumors.

 

Acknowledgments: This work was supported by the Faculty of Medicine, University of Novi Sad, Serbia,  Clinical Centre of Vojvodina, Clinic for Maxillofacial and Oral Surgery.

Contact: Cankovic Milos, Dentistry Clinic, Faculty of  Medicine, Hajduk Veljkova 12, Novi Sad, Serbia, +381637781739; +38121661-2222, E-mail: doctore@uns.ac.rs

 

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