Objective To explore the clinical significance and the impact on prognosis of blood micrometastasis in the patients with pN0 esophageal squamous cell carcinoma. Methods Total RNA was extracted with TRIzol and mRNA was transcribed reversely into cDNA. RT-PCR was used to detect MMP-7 mRNA and hTERT mRNA in blood. △△Ct sample values were calculated with post-operative follow-up of 3 month, 6 month, 12 month. Results Statistical results suggested that blood micrometastasis was related to differentiation grade and pTNM staging (P=0.000, P=0.000 respectively), but not to age, sex, length of turnout (P0.05). Follow-up results suggested that the degree of invasion and tumor metastasis (recurrence) was no correlation; follow-up to 6 month and 12 month, tumor metastasis (recurrence) was associated with blood micrometastasis, and follow-up to 12 month, compared with the tumor metastasis (recurrence) probability of blood micrometastasis-positive patients and negative patients, the former was as 6.44 times as the latter. (OR=6.440, 95 % CI 1.547-26.822). Conclusion Blood micrometastasis testing is of great significance to early diagnosis and prognosis judgment in pN0 esophageal squamous cell carcinoma patients.

Two cell strains from human pancreatic cancer taken surgically were transplanted to the pancreas of pureline BALB/C-nu/nu nude mice and 9 generations of PTNMP-1 and 6 generations of PTNMP-2 were obtained. Biological properties were studied. It yielded a transplant success rate of 95% - 100% and large amount of CEA. Analysis of the karyotype confermed that they retained the karyotype of human cancer cells. Some lymphatic and blood stream metastasis and invasion could be found in the nude mice orthotopically transplanted with tumour, showing that the transplanted tumour had characteristics identical with the donor tumour.