In a study reported in a research letter in JAMA Oncology, Matsuo et al found that survival without adjuvant therapy in women with low-risk endometrial cancer was poorer among those with isolated tumor cells (ITCs) vs no lymph node metastasis in regional lymph nodes.
Study Details
The cohort study used National Cancer Database data from 2018 to 2022, identifying patients with ITCs (a cluster of tumor cells measuring no more than 0.2 mm or with no more than 200 cells in the regional nodes) and those with no nodal metastasis. All patients had undergone hysterectomy and node evaluation without receipt of adjuvant chemotherapy or radiotherapy. Survival outcomes were compared using inverse probability of treatment weighting (IPTW) analysis.
Key Findings
The ITC group consisted of 271 patients (mean age = 59.8 years). The node-negative group consisted of 43,289 patients (mean age = 60.7 years). Median follow-up was 3.1 years (interquartile range [IQR] = 2.1–4.3 years) in the ITC group and 3.3 years (IQR = 2.2–4.6 years) in the node-negative group.
In the IPTW cohort, 4-year overall survival was 89.5% (95% confidence interval [CI] = 84.5%–94.9%) in the ITC group vs 96.3% (95% CI = 96.1%–96.5%) in the node-negative group (hazard ratio [HR] = 3.15, 95% CI = 2.04–4.87).
Results for 4-year survival were similar to overall results in the IPTW cohort for the ITC group vs the node-negative group in patients aged 60 years or older (HR = 3.47, 95% CI = 2.14–5.61), those with grade 1 endometrioid histology (HR = 3.77, 95% CI = 2.32–6.14), and those with a tumor size of 4 cm or smaller (HR = 3.46, 95% CI = 1.90–6.31).
The investigators concluded: “In this cohort study, the presence of ITCs in regional lymph nodes was associated with decreased [overall survival] compared to no nodal metastasis for patients in the uterine factors–based low-risk endometrial cancer group who underwent surgery without adjuvant therapy. The 4-year [overall survival] rate of approximately 90% in the ITCs group was considered lower than expected for otherwise low-risk endometrial cancer. These statistics suggest that ITCs in regional lymph nodes may be prognostic in low-risk endometrial cancer.”
Koji Matsuo, MD, PhD, of Division of Gynecologic Oncology, University of Southern California, Los Angeles, is the corresponding author for the JAMA Oncology article.
DISCLOSURE: The study was supported by the Ensign Endowment for Gynecologic Cancer Research. For full disclosures of the study authors, visit jamanetwork.com.
