Distribution of surviving tumor cells after chemoradiotherapy in tongue and floor of mouth carcinomas.
BACKGROUND
Conservative surgery according to the clinical response to induction therapy is applied in breast carcinomas but not yet in head and neck carcinomas. The possibility of conservative surgery after induction therapy for preservation of function was examined.


METHODS
Forty-three tongue and 15 floor of mouth carcinomas that had received induction therapy and tumor resection were submitted for a comparative investigation on the clinical effect of induction therapy and cancer cell degeneration, which was examined in semiserial specimens from the bread-loaf sections of the excised materials, and a classification of the surviving tumor cell distribution in the tissue was proposed. The distribution was divided into four patterns according to the dispersion and volume of the remaining tumor cells (pattern I, no surviving tumor cells; pattern IIA, viable tumor cells in the central superficial region of the original tumor tissue; pattern IIB, viable cells in the superficial portion, but distributed widely; pattern III, massive tumor cell nests in the deep portion, but centrally localized; pattern IVA, sporadical viable cell islands, but not in the periphery; and pattern IVB, diffuse viable cells scattered throughout the original tumor tissue).


RESULTS
The original tumor size did not affect the remaining viable tumor cell distribution pattern, but sporadic distribution patterns (patterns IVA and IVB) were observed in most of the T4 cases. In many cases, especially in tumors of the nondiffuse invasion type (invasion of grade 1 and 2), the tumor remission rate was inversely correlated with the dispersion of the viable tumor cells. However, some cases of grade 3 and 4 invasion exhibited sporadical surviving tumor cells even though a high tumor remission rate was obtained. These tumors, especially those located on the floor of the mouth, recurred with high frequency.


CONCLUSIONS
Conservative surgery can be applied to nondiffuse invasion cases, according to the tumor remission rate. In T3 and T4 cases exhibiting grade 3 or 4 invasion, conservative surgery is ill-advised, even if more than 90% tumor remission is obtained.
Department of Oral Surgery, Kochi Medical School, Japan.
T
T
Osaki
J
J
Hirota
K
K
Yoneda
T
T
Yamamoto
E
E
Ueta
D002277:Carcinoma / Q000473:pathology* / Q000628:therapy; D002470:Cell Survival; D003131:Combined Modality Therapy; D006801:Humans; D009062:Mouth Neoplasms / Q000473:pathology* / Q000628:therapy; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012074:Remission Induction; D014062:Tongue Neoplasms / Q000473:pathology* / Q000628:therapy