Clinicopathological study on para-aortic lymph node metastasis without pelvic lymph node metastasis in endometrial cancer

Aim One of the important risk factors for recurrence of endometrial cancer is lymph node metastasis. The regional lymph nodes are pelvic lymph nodes (PLN) and para-aortic lymph nodes (PAN). PAN metastasis was often detected in the cases with PLN metastasis. However, PAN metastasis not associated with PLN metastasis was identified in a few cases. We focused on nine cases with PAN metastasis and without PLN metastasis. Material and Methods The subjects of this study were 260 cases that were diagnosed with endometrial cancer. The initial treatments were surgery, including pelvic and para-aortic lymphadenectomy. Nine of these cases had PAN metastasis but did not have PLN metastasis. We retrospectively analyzed the clinicopathological factors and prognosis in cases with PLN-PAN+ cases. Results A total of 91 (35%) cases were identified as positive for either PLN or PAN. PAN metastases were detected in 62.6% of the cases that had some regional lymph node metastases and 3.5% of all cases were PLN- and PAN+. In all PLN-PAN+ cases, PAN swelling was not detected by preoperative chest-abdominal computed tomography scan. There were no clear trends among risk factors of regional lymph node metastasis. The 5-year progression-free survival was 87.1% for PLN-PAN- cases, 67.5% for PLN+PAN- cases, 44.4% for PLN-PAN+ cases, and 33.2% for PLN+PAN+ cases. Conclusion During diagnosis and treatment for endometrial cancer, PLN-PAN+ cases should also be considered because the prognosis in PLN-PAN+ cases tended to be lower than that in PLN-PAN- cases and PLN+PAN- cases.