Effects of preoperative immunochemoradiotherapy and chemoradiotherapy on immune responses in patients with rectal adenocarcinoma.
BACKGROUND
We previously reported that preoperative chemoradiotherapy (CRT) combined with intraoperative electron irradiation for cT3/T4 adenocarcinoma of the rectum reduced the local recurrence, with significant improvement of survival. Radiotherapy has been reported to reduce immune function. We examined the effects of PSK, a protein-bound polysaccharide, concomitant with preoperative CRT on immune responses.


METHODS
Thirty patients with cT3/T4 adenocarcinoma of the rectum were randomly assigned to 2 weeks' irradiation and 4 weeks' S-1 administration before surgery (control group), or the same CRT with simultaneous 4 weeks' PSK administration (PSK group). Both systemic and local immune responses were evaluated.


RESULTS
Significant increase of natural killer cell count in the peripheral blood and cytotoxic T-cell counts in the peri-tumoral and normal mucosa, and a significant decrease of serum immunosuppressive acidic protein level were observed in the PSK group.


CONCLUSIONS
Combined use of PSK with preoperative CRT may improve immune function.
Sadahiro
Sotaro
S
Department of Surgery, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, 259-1193, Japan. sadahiro@is.icc.u-tokai.ac.jp
Suzuki
Toshiyuki
T
Maeda
Yuji
Y
Tanaka
Akira
A
Kamijo
Akemi
A
Murayama
Chieko
C
Nakayama
Yuko
Y
Akiba
Takeshi
T
D000230:Adenocarcinoma / Q000097:blood / Q000276:immunology* / Q000628:therapy*; D000368:Aged; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000627:therapeutic use*; D007694:Killer Cells, Natural / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care / Q000379:methods; D011509:Proteoglycans / Q000627:therapeutic use*; D012004:Rectal Neoplasms / Q000097:blood / Q000276:immunology* / Q000628:therapy*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D007155:Immunologic Factors; D011509:Proteoglycans; C010770:polysaccharide-K