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10 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
POLE-ultramutated endometrial cancer carries a fault in the proofreading part of a DNA-copying enzyme, so its cells pile up enormous numbers of mutations. It looks aggressive under the microscope yet almost never comes back after surgery, so trials are testing whether radiotherapy and chemotherapy can be dropped altogether.
The Cancer Genome Atlas defined the POLE-ultramutated class in 2013: tumours with a hotspot mutation in the exonuclease domain of DNA polymerase epsilon, most often P286R or V411L, which carry more than a hundred mutations per megabase, far more even than mismatch-repair-deficient tumours. About seven percent of endometrial cancers fall into this class. They are more often high grade, endometrioid, with prominent lymphocyte infiltration and ambiguous histology, and they occur in younger, thinner women than the average endometrial cancer patient. Because the pathogenic hotspots are few, a targeted sequencing test settles the class, and the ProMisE algorithm and the WHO 2020 classification both place POLE testing first because a POLE mutation overrides an abnormal p53 or mismatch-repair result.
The defining clinical fact is an excellent outcome regardless of grade or stage. In the molecular analysis of PORTEC-3, women with POLE-ultramutated tumours had almost no recurrences in either arm, so chemotherapy added nothing; the same pattern appeared in PORTEC-1 and PORTEC-2 and in the TransPORTEC pooled cohorts. The ESGO/ESTRO/ESP 2021 guideline therefore lets clinicians omit adjuvant therapy for stage I and II POLE-ultramutated disease, and the RAINBO programme's POLEmut-BLUE trial is testing de-escalation prospectively: no adjuvant treatment for stage I and II tumours and radiotherapy alone for stage III. The rationale is that the ultramutated tumour is intensely immunogenic and any residual cells are cleared by the immune system after surgery.
| Setting | Approach | Guideline |
|---|---|---|
| Diagnosis and classification | Hysterectomy with bilateral salpingo-oophorectomy and sentinel node mapping; molecular classification of every endometrial cancer with POLE sequencing, MMR and p53 immunohistochemistry. | not mapped |
| Stage I to II after surgery | Observation without adjuvant treatment is acceptable under the ESGO/ESTRO/ESP guideline; vaginal brachytherapy where local protocol still requires it. | not mapped |
| Stage III after surgery | Pelvic radiotherapy without chemotherapy, as in RAINBO POLEmut-BLUE; chemoradiation with chemotherapy remains an option outside trials. | not mapped |
| Advanced or recurrent (rare) | Checkpoint inhibitor with or without chemotherapy by extrapolation from the mismatch-repair-deficient class. | not mapped |