| Purpose: Rectal cancer is one of the most common carcinoma. Approximately 50% of patients who undergo a histological curative surgical procedure nevertheless subsequently develop recurrence or metastatic disease. It is considered that blood metastases only occurred in the middle and advanced rectal cancer and main through lymphatic-vein route, but clinics proved that even in the early focus, blood metastases occurred even before the lymphatic metastases, only the early blood metastases is not easy discovered. Except the widely regarded lymphatic metastatic route, peripheral blood micro-metastases of tumor cells the minimal tumor cells or tiny cancer focus residual in the abdominal cavity before or after resection is an important cause that resulted in the postoperative peritoneal spread recurrence and metastases. In clinical practice, we always regard the diagnosis and treatment of the peripheral blood metastases and peritoneal spread of rectal cancer cells towards the rectal cancer patients located above the peritoneal reflex. But to the rectal cancer patients located below the peritoneal reflex, we always just regard the regional extensive resection and lymphatic cleaning, andeasy to omit that lower rectal cancer still can metastases to the peritoneum abdominal organs along the lymph and blood route, leads to the deficiency of synthetic therapy, and occurred post-operation peritoneal spread recurrence and metastases than can be avoided, induced great prognosis judgment avoidance; if we treat all patients underwent curative surgery chemotherapy, patients who needn't chemotherapy at all will endure unnecessary waste and ill effect of chemotherapy drugs. So it's very important for the tumor synthetic therapy , exactly judging prognosis that exactly judging whether tumor micrometastases existed in the peripheral blood abdominal cavity of lower rectal cancer patients. A traditional measures to check micrometastases, as less precision, clinical meaning is little guidance. With the development of molecular-biology, especially with the mature and perfect of the reverse transcription polymerase chain reaction technique, RT-PCR, it's possible to detect the metastastic tumor cells in the peripheral blood and abdominal cavity. The study use CEA, CD44 as target, utilizing RT-PCR technique to detect micrometastases in the peripheral blood peritoneal lavage of the lower rectal cancer patient and discuss the probability of detecting, to study the relationship between micrometastases and the clinical biobehaviors, to provide theoretical basis of the synthetic therapy for intro- or after- the surgery with lower rectal cancer patients. Materials and methods: Rectal cancer cell lines SW480were cultured in RPMI 1640 media supplemented with 10% fetal calf serum. RNA was extracted by Trizol method, and stored at -80. 35 lower rectal cancer patients were selected randomly from patients underwent surgery in the Surgical Department of the Fourth Affiliated Hospital of HeBei Medical University from August 2000,to June 2001. 5 patients were benign illness in the abdominal cavity. All rectal cancer patients were histologically validated. There are 23 males and 12 females, aged 26 to 80 years (average 55 years old) and 11 Dukes' A stage, 13 Dukes' B stage, 9 Dukes' C stage, 2 Dukes' D stage. 5ml vein blood was got by 5ml sterile syringe pretreated by 0.5 ml heparin before therapy (surgery, radiotherapy, chemotherapy), nucleus cells were separated by lymphocyte extraction fluid, and RNA was extracted by Trizol method, stored at -80 'C for the RT-PCR examination. After the initial of the surgery, 100ml peritoneal washes were obtained, 50ml washes were done the peritoneal lavage cytology (PLC), RNA was extracted by Trizol method from the latter 50ml washes after centrifugation, after the gel electrophoresis and no degradation occurred, reverse transcribe was done. P -actin was the inner consultation standard by the transcribed cDNA, tumor cells existence were judged by CEA CD44v's expression through the amplification of the CEA... |
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