Interplay Between Anatomic and Molecular Factors in the Current Management of Endometrial Cancer

The case presented here offers various dilemmas, for which answers are unclear and are being answered by ongoing studies. 1 Yuan J Sun SY Isolated tumor cells in sentinel lymph nodes: Does it really matter?. Int J Radiat Oncol Biol Phys. 2023; 117: 297 Abstract Full Text Full Text PDF PubMed Scopus (3) Google Scholar For stage IA, grade 1 with substantial lymphovascular space invasion (LVSI), American Society for Radiation Oncology guidelines favor brachytherapy while European guidelines place this patient in at least the high-intermediate-risk group, favoring external beam radiation therapy. The revised quantification of PORTEC-1 and -2 data found that patients with ≥4 involved vessels (substantial LVSI) had a 26.3% rate of pelvic lymph node recurrence compared with 6.7% for 1 to 3 foci (focal LVSI) and 3.3% with no LVSI. However, in the PORTEC studies, lymph nodes were not pathologically assessed. This patient had sentinel lymph node biopsy done showing isolated tumor cells, which are considered node negative, but do increase the risk of additional nodal involvement (range, 0%-10%). One recent study also found that nodal involvement on sentinel lymph node biopsy, including isolated tumor cells, was increased for patients with substantial LVSI. 2 Pifer PM Bhargava R Patel AK et al. Is the risk of substantial LVSI in stage I endometrial cancer similar to PORTEC in the North American population? A single-institution study. Gynecol Oncol. 2020; 159: 23-29 Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar For these reasons, we would favor external beam radiation therapy with intensity modulated radiation therapy in this patient, as our preferred adjuvant treatment, provided the ≥4 involved vessels definition was used to define substantial LVSI.