Clinical significance of lymphovascular invasion in rectal cancer following neoadjuvant therapy / 中华消化外科杂志

ABSTRACT

Objective To investigate lymphovascular invasion (LVI) in mid-low rectal cancer following neoadjuvant therapy. Methods A total of 297 consecutive patients with mid-low rectal cancer received radical surgery from August 2002 to August 2005 at Beijing Cancer Hospital. All patients were divided into the neoadjuvant therapy group and a control group according to whether they underwent preoperative radiotherapy or radiochemotherapy. Histological assessment of tumor specimens was made, and correlation of LVI and prognosis was analysed using the chi-square test. The disease-free survival rate and overall survival rate were analysed by the Kaplan-Meier survival curve. Results The overall positive rate of LVI was 23.9% (71/297). The positive rates of LVI in neoadjuvant therapy group and control group were 21.5% (31/144) and 26. 1% (40/153), respectively,with no significant difference between the groups ( x2 = 0.872, P ＞ 0.05). In the neoadjuvant therapy and control groups, LVI was significantly associated with pathologic T and N stages as well as the degree of histological differentiation (x2 =13.490, 27.401,7.323;16. 188, 21.623, 16.534, P＜0.05). In the control group, LVI was closely associated with local recurrence (x2 =4. 010, P ＜0.05 ), whereas this was not the case in the neoadjuvant therapy group (x2 =0.000, P＞0.05). LVI was significantly associated with distal metastasis in both the neoadjuvant therapy and control groups (x2 = 4.950, 14. 332, P ＜ 0.05 ). The disease-free and overall survival rates of patients with LVI were 46.4% (26/56) and 56.7% (34/60), which were significantly lower than 75.1%(148/197) and 79.4% ( 166/209 ) of those with no LVI, respectively ( x2 = 16. 720, 12.660, P ＜ 0.05 ).Conclusions Neoadjuvant therapy does not significantly reduce LVI;however, the biological behaviour of LVI has changed. Patients with LVI may benefit from neoadjuvant radiotherapy.