Deep sequencing.

Top Line: What is the optimal sequence of chemotherapy and radiation for women with node positive (IIIC) endometrial cancer?

The Study: Women with stage IIIC (lymph node positive) endometrial cancer benefit from both chemotherapy and radiation. The combined modality arms of both GOG-258 and PORTEC-3 included both concurrent chemoradiation and adjuvant chemo. However, there are other combinations of chemo and radiation out there. This study used a large multi-institutional cohort of nearly 700 patients to compare outcomes for different chemo and radiation sequences following definitive surgery in patients with node positive endometrial cancer. All patients underwent hysterectomy, bilateral salpingo-oophorectomy, and pelvic node dissection with about ⅔ also having para-aortic node dissection. About ⅔ of patients had pelvic nodal disease (IIIC1) and endometrioid histology, respectively. Adjuvant therapy regimens were categorized as upfront chemo (chemo alone → RT), concurrent (chemo/RT→ chemo), sandwich (chemo→ RT→ chemo), upfront RT (RT alone→ chemo), and finally chemo alone with vaginal cuff brachytherapy. Overall, treatment sequence was not associated with OS or RFS, and this still held true after stratifying for histology and grade. The type of radiation delivered was also not associated with OS or RFS. While chemo-brachy was associated with more nodal recurrences, distant metastasis was the most common site of recurrence overall. 

TBL: The sequence of chemotherapy and radiation does not appear to significantly affect treatment outcomes for women with resected stage IIIC endometrial cancer. | Hathout, Int J Radiat Oncol Biol Phys 2021