Pre-operative radio-chemotherapy enhances apoptotic cell death in oral squamous cell carcinoma.
The effect of pre-operative radio-chemotherapy (RCT) has been examined in a total of 15 oral squamous cell carcinomas (SCCs), in terms of apoptosis (cell loss) and proliferation. All the patients received pre-operative radiation at a dosage of 30 or 40 Gy, as well as anticancer agents including tagaful (FT), 5-fluorouracil (5-FU), bleomycin (BLM) and peplomycin (PEP). Surgical specimens were obtained before and after RCT, and serial sections were prepared for immunohistochemistry for p53 oncoprotein and Ki-67 antigen, as well as for terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL). TUNEL indices (TI; percentage of TUNEL-positive cells in the tumor cells) before and after RCT were 1.2+/-1.1 and 4.7+/-2.9 in the nine well-differentiated oral SCCs, and 1.0+/-0.7 and 3.9+/-2.1 in the six poorly differentiated SCCs, respectively. Similarly, Ki-67 indices (KI; percentage of Ki-67 antigen-positive cells in tumor cells) before and after RCT were 31.1+/-14.2 and 15.8+/-11.1 in the former, and 37.1+/-7.8 and 8.7+/- 13.4 in the latter, respectively. Thus, pre-operative RCT enhanced apoptotic cell death and abated proliferative activity significantly (P<0.05), regardless of histological differentiation. Enhancement of apoptosis was more prominent in the group treated with FT or 5-FU than with BLM or PEP. Oral SCC with >20% of nuclear p53-positive tumor cells was noted in six cases. Enhanced TI and abadement of KI did not differ among the p53-positive and -negative tumors.
Doi
R
R
First Department of Pathology, Tottori University, Yonago, Japan.
Makino
T
T
Adachi
H
H
Ryoke
K
K
Ito
H
H
D000328:Adult; D000368:Aged; D017209:Apoptosis; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D011300:Preoperative Care; D018714:Radiotherapy, Adjuvant; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53