Molecular prognostic factors in locally irresectable rectal cancer treated preoperatively by chemo-radiotherapy.
OBJECTIVE
The aim of this study was to determine the relationship between survival and value of molecular markers in the primary tumour in a group of patients with irresectable rectal cancer, treated with preoperative chemo-radiotherapy.


METHODS
Immunohistochemistry for p53, p21, bcl-2 and Ki-67 was performed on pre-treatment biopsy specimens of 34 patients with irresectable rectal cancer. Preoperative treatment consisted of pelvic irradiation of 45-56 Gy, combined with 5FU and leucovorin (350/20 mg/m2 x 5 d; in weeks 1 and 5 during radiotherapy). The median follow-up was 38 months. Endpoints were pathological T-stage and survival after surgery.


RESULTS
Expression of p21 correlated significantly with survival (p=0.005). Survival and p21 expression also correlated significantly, when adjusted for tumour response (p=0.005, RR=4.8 (1.6-14.7)).


CONCLUSIONS
Expression of p21 predicts a worse survival in irresectable rectal cancer treated with preoperative chemo-radiotherapy. No relationship was found between tumour response in chemo-radiotherapy and p53, bcl-2 or Ki-67.
Reerink
Onne
O
Department of Radiotherapy Oncology, University Hospital Groningen, The Netherlands.
Karrenbeld
Arend
A
Plukker
John T M
JT
Verschueren
René C J
RC
Szabó
Ben G
BG
Sluiter
Wim J
WJ
Hospers
Geke A P
GA
Mulder
Nanno H
NH
D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000096:biosynthesis* / Q000235:genetics; D020360:Neoadjuvant Therapy; D011300:Preoperative Care; D011379:Prognosis; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics; D012004:Rectal Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000628:therapy*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis* / Q000235:genetics
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D019394:Ki-67 Antigen; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53