Tumor size in endometrial cancer

Tumor size was determined in 142 patients with clinical Stage I endometrial cancer treated primarily by total abdominal hysterectomy, bilateral salpingo‐oophorectomy, and lymph node biopsies between July 1979 and August 1988. Only 4% of patients with tumor size less than or equal to 2 cm had lymph node metastasis; this increased to 15% for tumors more than 2 cm and increased further to 35% when the entire uterine cavity was involved (multivariate P = 0.01). Five‐year survival was 98% for patients with tumors less than or equal to 2 cm, 84% with tumors more than 2 cm, and 64% with tumors involving the whole uterine cavity (Mantel‐Cox P = 0.005). For endometrial cancer patients with Grade 2 tumors and less than one‐half myometrial invasion, the risk of lymph node metastasis is often considered too low to justify adjuvant pelvic radiation therapy. This intermediate‐risk group is better defined by including tumor size as a prognostic factor. For this subgroup (Grade 2, less than one‐half endometrial invasion) there were no lymph node metastasis associated with tumors less than 2 cm, but 18% had nodal disease when tumors were larger than 2 cm. Tumor size is an important prognostic factor that is particularly helpful in directing adjuvant radiation therapy in patients without staging lymph node biopsies.