Promotional effects of CO(2) laser and scalpel incision on 4-NQO-induced premalignant lesions of mouse tongue.
OBJECTIVE
CO(2) laser and scalpel incision have been demonstrated to have promotional effects on oral neoplastic lesions. However, a precise understanding has not been achieved as to which modality has a more significant effect on cancer promotion. The purpose of this study was to determine the histological and biological changes after CO(2) laser surgery and scalpel incision in oral premalignant lesions.


METHODS
Premalignant lesions of mouse tongue induced by 4-nitroquinoline-1-oxide (4NQO) in drinking water for 4 months were used in this study. A 2-mm incision was made on the right margin of each mouse tongue, using either a CO(2) laser (group A) or a scalpel (group B). Mice without incisional treatment were used as controls (group C). Seven months after laser and scalpel treatments, hematoxylin-eosin staining and proliferating cell nuclear antigen (PCNA), epidermal growth factor receptor (EGFR), and p53 immunostaining were performed for tongue specimens.


RESULTS
The epithelia of right tongue margins showed more severe dysplasia than those of left tongue margins in both group A and group B. The PCNA labeling indices (LIs) and EGFR expression for right tongue margins were also higher than for left margins in both group A and group B. There was no obvious difference between these two groups. Almost no p53-positive staining was found in either group.


CONCLUSIONS
CO(2) laser surgery and scalpel incision seem to have similar promotional effects on oral premalignant lesions.
Ma
G
G
Second Department of Oral and Maxillofacial Surgery, Nagasaki University School of Dentistry, Nagasaki 852-8588, Japan.
Sano
K
K
Ikeda
H
H
Inokuchi
T
T
D015112:4-Nitroquinoline-1-oxide; D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis; D002273:Carcinogens; D066246:ErbB Receptors / Q000032:analysis; D007150:Immunohistochemistry; D053685:Laser Therapy / Q000009:adverse effects*; D008297:Male; D051379:Mice; D008808:Mice, Inbred CBA; D011230:Precancerous Conditions / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D014059:Tongue / Q000473:pathology / Q000601:surgery*; D014062:Tongue Neoplasms / Q000209:etiology* / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D014408:Biomarkers, Tumor; D002273:Carcinogens; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53; D015112:4-Nitroquinoline-1-oxide; D066246:ErbB Receptors