LYMPH-NODE INVOLVEMENT AND TUMOR DEPTH IN RECTAL CANCERS - AN ANALYSIS OF 805 PATIENTS

BACKGROUND: Superficial rectal tumors are said to involve regional lym ph nodes rarely. This presumption must be proven beyond any doubt if l ess radical surgery is to be offered for such patients. PATIENTS AND M ETHODS: Eight hundred five cases (467 males; median age, 64 (range, 19 -97) years) of rectal cancer were reviewed. RESULTS: Lymph node positi vity, number of lymph nodes involved, lymphatic vessel, and venous and perineural invasion were significantly increased with increasing dept h of invasion of tumor through the bowel wail in univariate analysis. The percentage of lymph node involvement at each tumor depth was as fo llows: T1, 5.7 percent; T2, 19.6 percent; T3, 65.7 percent; T4, 78.8 p ercent. Overall lymph node involvement was 59 percent. For patients yo unger than 45 years of age, the percentage of lymph node involvement w as 33.3, 30, 69.3, and 83.3 percent compared with 3.1, 8.4, 64.2, and 78.8 percent for patients aged 45 years or above for T1, T2, T3, and T 4, respectively. CONCLUSION: Increased depths of tumor penetration bey ond T1 and age less than 45 years have an excessive incidence of lymph node positivity. The finding of lymphatic vessel invasion on biopsy i s highly indicative of lymph node metastasis.