大腸癌のリンパ節転移個数と予後 The Relationship between the Number of Metastatic Lymph Nodes and Prognosis of Patients with Colorectal Cancer

1977年から1989年までに当科で治癒切除を受けた大腸癌取扱い規約のstage III,IVの大腸癌症例のうち,深達度ss,sまたはa_1,a_2の100例を対象として,転移リンパ節個数と予後の関係について検討した.転移個数を1個,2個,3個,および4個以上に分けて5年生存率を比較すると,それぞれ56%,63%,34%,35%であった.転移個数を2個以下と3個以上の2群に分けて5年生存率を比較すると,それぞれ59%,35%であり,両群間に有意差が認められた.一方,TNM分類に準じた3個以下と4個以上の比較では,それぞれ54%,35%であり,統計学的有意差ではなかった.さらに,大腸癌取扱い規約に基づくn_1転移陽性例のみの比較でも,転移個数3個以上では2個以下に比して治療成績不良であった.以上より,転移リンパ節個数2個以下と3個以上の2群に群別することは,予後を推測するうえで有用であると考えられる.

We examined the relationship between the number of metastatic lymph nodes and prognosis of patients with colorectal cancer. One hundred patients with histologically proven lymph node metastasis and depth of wall invasion of ss(a_1)or s(a_2)underwent curative surgery for colorectal cancer in our department between 1977 and 1989. The 5-year survival rates for patients with 1, 2, 3 and 4 or more metastatic nodes were 56%, 63%, 34%, 35% respectively. Based on the above result, the patients were divided into 2 groups, those with 1 or 2 metastatic lymph nodes and those with 3 or more nodes, and the 5-year survival rates of the two groups were compared. The rate was 59% in the first group and 35% in the second, the difference being statistically significant. When the 5-year survival rate was calculated for patients with 1-3 metastatic lymph nodes and those with 4 or more nodes according to the TNM classification by the UICC, it was 54% in the first group and 35% in the second, but the difference was not significant. It appears likely that the classification of cases by 1 or 2 metastatic lymph nodes and 3 or more nodes is more useful for predicting the prognosis for patients with colorectal cancer.