Molecular classification served as a significant marker of survival following endometrial cancer (EC) recurrence, with patterns of recurrence that varied based on molecular subgroups, according to findings published in Gynecologic Oncology.

“Over the past years, the management of [EC] has become considerably more personalized, mainly as a result of the introduction of the new molecular classification and of sentinel lymph node mapping,” Sara Imboden, MD, of the University of Bern, and colleagues wrote. “Prospective studies taking the molecular classification into account are finally on the way to optimize treatment strategies.”

Dr. Imboden and colleagues aimed to determine the value of molecular classification in patients with recurrent EC. The study included 594 patients with molecularly classified EC who had primary surgical treatment between 2004 and 2015 at the Karolinska University Hospital, Sweden, and the Bern University Hospital, Switzerland.

Recurrence & Survival Vary by Tumor Type

Of the total study cohort, 101 patients had a recurrence. These included the following tumor types: polymerase epsilon ultra-mutated (POLEmut; N=2), mismatch repair deficient (MMRd; N=33), p53 abnormal (p53abn; N=30), and non-specific molecular profile (NSMP; N=36). The mean age at recurrence was 71 and the mean follow-up time was 54 months.

Median time to first recurrence was 16 months (95% CI, 12-20 months). The shortest median time was seen in MMRd patients (13 months; 95% CI, 5-21 months). Investigators found that the pattern of recurrence was distinct among molecular subgroups; MMRd tumors had more locoregional recurrences, while p53abn cases had more abdominal recurrences. Median survival following recurrence was best for MMRd cases (43 months; 95% CI, 11-76 months) compared with 39 months (95% CI, 21-57 months) and 10 months (95% CI, 7-13 months) for NSMP and p53abn cases, respectively (log-rank, P=.001).

Mean age at the time of recurrence for the 101 patients who experienced a recurrence was 71, and the mean BMI was 30 kg/m2. A minimally invasive surgical approach for primary staging surgery was used in 68 patients, including 40 laparoscopic surgeries and 28 robotic surgeries. Lymphadenectomy was done in 64 patients, with a mean of 34 lymph nodes removed per patient. Most patients with recurrence had grade 3 tumors (54%) and 56% had lymphovascular space invasion.

Directions for Future Research

Overall, the study results demonstrated that MMRd EC had more locoregional recurrence and the best survival rates following recurrence, whereas p53abn cases had abdominal recurrence more frequently and experienced the poorest prognosis of all patients with recurrence.

“To the best of our knowledge, this is the first study analyzing the association of molecular classification with pattern of recurrence and survival after recurrence in [EC],” Dr. Imboden and colleagues wrote.

The study team also noted that, while the study provided “evidence of different intrinsic tumor biologies among the molecular subgroups affecting the pattern of recurrence and the survival after recurrence,” the association of molecular subgroup, pattern of recurrence, and oncological outcome should be investigated in prospective studies.