OBJECTIVETo explore the association of the expression of hypoxia-inducible factor 1α (HIF-1α) with microlymphatic vessel density(MLVD) and lymph node micro-metastasis in rectal cancer.

METHODSThe experimental group consisted of 40 middle-low rectal cancer specimens pathologically confirmed at the First Affiliated Hospital of Anhui Medical University between 2000 and 2003. Forty samples of normal tissues taken from the corresponding area around the cancer were used as the control group. Immunohistochemistry was used to detect HIF-1α expression and MLVD in both the tumor tissues and the adjacent normal tissues. Lymph node micrometastasis was ascertained using immunohistochemical staining with CK20.

RESULTSIn rectal cancer tissues, the HIF-1α expression was 77 386±14 911 and MLVD was 7.3±0.7, significantly higher than those in normal adjacent tissues(33 092±5877 and 0.3±0.2, both P<0.01). The HIF-1α expression was positively correlated with MLVD in rectal cancer(r=0.781, P<0.01). Thirty-one patients had no lymph nodes metastasis and 10 had micrometastasis. The HIF-1α expression and MLVD in specimens with lymph node micrometastasis was significantly higher than that in those without lymph node micrometastasis(P<0.05).

CONCLUSIONHIF-1α and MLVD play important roles in the development of rectal cancer,which may promote lymphatic micrometastasis in rectal cancer.