Introduction

Not every practice-relevant finding from the 2026 ASCO Annual Meeting comes from a single blockbuster trial. Four updates spanning cervical, ovarian, and endometrial cancer are worth a clinician's attention this year: a reminder that a well-established curative treatment is being underused, an early look at circulating tumor DNA (ctDNA) as a recurrence marker in ovarian cancer, new data connecting endometrial cancer surgery to long-term cardiovascular risk, and a genuinely novel way of estimating cure rates in endometrial cancer using long-term follow-up from the RUBY trial.

A Reminder: Cervical Cancer Cannot Be Cured Without Brachytherapy

Concurrent chemoradiation with brachytherapy remains the standard of care for locally advanced cervical cancer (LACC), and brachytherapy is not an optional add-on. A review of US Oncology electronic medical record data from 2018 to 2022, spanning a large national community oncology database, found that only 76% of patients with LACC received brachytherapy as part of their treatment. Why the remaining 25% did not receive it is unclear from the data; the review suggests that attention has focused more on the choice between IMRT and VMAT for external beam radiation than on ensuring brachytherapy is delivered at all.

This is worth stating plainly: locally advanced cervical cancer cannot be cured without brachytherapy, regardless of how advanced the external beam technique is. This is a stage of disease with a high expected cure rate when treated correctly, and a gap this size in a large national dataset warrants attention from every practice treating cervical cancer. If a radiation oncology partner is not offering brachytherapy as part of a LACC treatment plan, that is worth a direct conversation.

ctDNA as a Recurrence Marker After Ovarian Cancer Debulking

Debulking status and CA-125 remain the current standard prognostic markers for recurrence in epithelial ovarian cancer, but circulating tumor DNA is emerging as a complementary tool. In a prospective cohort study, ctDNA was detected in 75% of patients overall (28 of 37), including ultra-low levels in 25% of cases.

The prognostic signal was striking in its early form: 85% of ctDNA-positive patients recurred, compared with zero recurrences among ctDNA-negative patients over an average follow-up of 7.6 months. Among optimally debulked patients, 82% of those who were ctDNA-positive recurred, versus none who were ctDNA-negative, though the follow-up interval here is still short. Unsurprisingly, 100% of suboptimally debulked patients recurred regardless of ctDNA status.

This is early, hypothesis-generating data rather than something ready to change practice today, but it points toward ctDNA eventually serving as an additional risk-stratification tool after ovarian cancer surgery, particularly for optimally debulked patients where current tools offer less discrimination.

Endometrial Cancer Surgery and Cardiovascular Risk

Endometrial cancer is increasingly being diagnosed in younger patients, and a comparison of patients undergoing oophorectomy at the time of endometrial cancer surgery against a benign comparison cohort found that the endometrial cancer group was younger, more likely to be of minority race, had higher BMI, and had increased rates of smoking, a risk profile that itself predicts cardiovascular disease. The study found a statistically significant increase in cardiovascular risk progression, including new-onset hypertension, atrial fibrillation, and need for antiplatelet therapy, in this population following oophorectomy.

Since cardiovascular disease, not cancer recurrence, is the predominant driver of non-oncologic mortality in endometrial cancer survivors, this reinforces a practical point: systematic cardiovascular risk assessment should be incorporated into routine endometrial cancer surveillance, not treated as an afterthought. It also strengthens the case, when oncologically appropriate, for ovarian preservation in younger patients with endometrial cancer, since early surgical menopause appears to compound an already elevated cardiovascular risk profile in this population.

RUBY: Modeling Cure Rates in Endometrial Cancer

The RUBY trial has already demonstrated that dostarlimab plus chemotherapy improves outcomes in dMMR/MSI-H endometrial cancer, and long-term follow-up presented this year adds a new dimension: an actual estimate of cure rate, using a statistical approach called a mixture cure model. This method distinguishes patients who are cured, meaning their long-term mortality risk reverts to that of the general population, from those with a durable but ultimately non-curative response.

At 55 months of follow-up, the robust overall survival benefit with dostarlimab plus chemotherapy was maintained, with a 66% reduction in risk of death versus placebo plus chemotherapy (HR, 0.34; 95% CI, 0.19–0.63); median overall survival was not reached in the dostarlimab arm versus 32.8 months with placebo. Applying the mixture cure model to this data, the estimated cure rate was 54% with dostarlimab plus chemotherapy versus 14% with placebo plus chemotherapy, a nearly fourfold increase in the estimated cured fraction.

This is a meaningful way to communicate what durable response actually means for a patient in front of you: a substantial proportion of patients treated with dostarlimab plus chemotherapy for dMMR/MSI-H endometrial cancer may, in fact, be cured of their disease rather than simply experiencing a prolonged remission. That is a genuinely new kind of conversation to be able to have with these patients, and one worth knowing about even if this specific statistical approach is unfamiliar.

For Patients

For people being treated for locally advanced cervical cancer, a specific type of radiation delivered from inside the body, called brachytherapy, is an essential part of curative treatment, not an optional extra. If a radiation plan for locally advanced cervical cancer does not include brachytherapy, it is worth asking your care team directly why not.

For people who have had surgery for ovarian cancer, a blood test that looks for circulating tumor DNA is being studied as an early way to help identify who is at higher risk of the cancer returning, though this is still early-stage research and not yet part of routine care.

For younger people diagnosed with endometrial cancer who are considering whether to keep their ovaries at the time of surgery, new data show that removing the ovaries is linked to a higher risk of cardiovascular problems like high blood pressure and irregular heart rhythm later on. This is worth discussing with your surgical team, since heart disease, not cancer recurrence, is the leading cause of death for many endometrial cancer survivors long-term.

For people with a specific subtype of advanced or recurrent endometrial cancer (called dMMR or MSI-high) being treated with dostarlimab plus chemotherapy, longer-term data suggest that roughly half of patients receiving this treatment may be cured of their cancer entirely, compared to about 1 in 7 patients who did not receive dostarlimab.

Key Takeaways

  • A national community oncology database review found only 76% of patients with locally advanced cervical cancer received brachytherapy, despite it being essential to curative treatment.

  • Early data suggest ctDNA after ovarian cancer debulking surgery is strongly associated with recurrence risk (85% of ctDNA-positive patients recurred versus 0% of ctDNA-negative patients), though follow-up remains short.

  • Oophorectomy at the time of endometrial cancer surgery was associated with a statistically significant increase in cardiovascular risk progression, supporting routine cardiovascular risk assessment in survivorship care.

  • Long-term RUBY trial data, using a mixture cure model, estimated a 54% cure rate with dostarlimab plus chemotherapy versus 14% with placebo in dMMR/MSI-H endometrial cancer, a nearly fourfold increase in estimated cured fraction.

References

  1. Szamreta D, et al. Radiotherapy use among locally advanced cervical cancer patients (LACC) in the United States community oncology setting. J Clin Oncol. 2026;44(suppl 16):abstr 5523.

  2. Anees M, et al. The use of circulating tumor DNA to stratify the risk of recurrence after surgical debulking in epithelial ovarian cancer. J Clin Oncol. 2026;44(suppl 16):abstr 5604.

  3. Presented at: 2026 ASCO Annual Meeting. Endometrial cancer surgery and cardiovascular risk factors following oophorectomy.

  4. Powell MA, et al. Robust overall survival benefit maintained at 4 years with dostarlimab plus chemotherapy in dMMR/MSI-H endometrial cancer: a mixture cure model analysis of the RUBY trial. Presented at: 2026 ASCO Annual Meeting.