Significance of stromal desmoplasia and myofibroblast appearance at the invasive front in squamous cell carcinoma of the oral cavity.
BACKGROUND
Tumor invasion involves complex interactions between tumor and stromal cells. We examined the extent of connective tissue in the tumor stroma and whether myofibroblasts play a role in assisting cancer invasion and metastasis.


METHODS
Biopsy materials from 84 patients with oral squamous cell carcinoma (SCC) were used. We compared data from intrastromal collagen fibers using Azan staining, immunohistochemical identification of myofibroblasts by cytoskeletal markers, alpha-smooth muscle actin, vimentin, desmin, and clinicopathological parameters. Clinical outcome was compared by 5-year survival rate.


RESULTS
There were high levels of stromal collagen fibers in invasive tumors. Myofibroblast appearance increased with increasing tumor invasiveness. Lymph node metastasis occurred more frequently in the myofibroblast-positive group, and the survival rate was significantly poorer in this group.


CONCLUSIONS
Fibrous stroma in SCC appeared to have a desmoplastic response. However, an independent invasive mechanism may regulate the stroma, with tumor desmoplasia occurring in highly developed, invasive tumors.
Department of Oral and Maxillofacial Surgery, Division of Cancer Science, Graduate School of Medical Science, Kanazawa University, Kanazawa Ishikawa 920-8640, Japan. skawa@med.kanazawa-u.ac.jp
Shuichi
S
Kawashiri
Akira
A
Tanaka
Natsuyo
N
Noguchi
Takashi
T
Hase
Hiromitsu
H
Nakaya
Teruhisa
T
Ohara
Koroku
K
Kato
Etsuhide
E
Yamamoto
D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D003094:Collagen / Q000378:metabolism; D003893:Desmin / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology*; D005887:Gingival Neoplasms; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D007822:Laryngeal Neoplasms / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology*; D009361:Neoplasm Invasiveness; D017154:Stromal Cells / Q000473:pathology; D014062:Tongue Neoplasms / Q000473:pathology
D003893:Desmin; D003094:Collagen