The following article features coverage from the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

Adjuvant chemotherapy given after chemoradiation did not provide a survival benefit over chemoradiation alone in patients with locally advanced cervical cancer, according to results from the phase 3 OUTBACK trial.1

The results were presented as a late-breaking abstract at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting by Linda Mileshkin, MBBS, of the Peter McCallum Cancer Centre in Melbourne, Australia, and colleagues.

The OUTBACK trial included 919 patients with locally advanced cervical cancer that was suitable for chemoradiation with curative intent. Patients were randomized to 2 treatment arms and stratified by nodal status, stage, age, participating site, and planned extended-field radiotherapy.

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Half of patients (n = 456) were assigned to standard cisplatin-based chemoradiation, and half (n = 463) were assigned to chemoradiation followed by adjuvant chemotherapy with 4 cycles of carboplatin and paclitaxel.

Dr Mileshkin noted that 22% of patients assigned to adjuvant chemotherapy did not receive it as planned.

The 5-year overall survival rates were similar between the treatment arms — 72% for the adjuvant chemotherapy arm and 71% for the control arm (hazard ratio [HR], 0.91; 95% CI, 0.70-1.18; P =.91).

The 5-year progression-free survival rates were similar between the arms as well — 63% in the adjuvant chemotherapy arm and 61% in the control arm (HR, 0.87; 95% CI, 0.71-1.08; P =.61).

Grade 3-5 adverse events within a year of randomization were more common in the adjuvant chemotherapy arm than in the control arm — 81% and 62%, respectively.

Quality of life was poorer while patients received adjuvant chemotherapy and for the first 3 to 6 months after. However, quality of life was similar between the treatment arms beginning at 12 months.

“The study confirms that chemoradiotherapy alone is currently our best possible treatment for women with locally advanced cervical cancer,” Dr Mileshkin said in a press release.2 “Not only is there no benefit with adjuvant chemotherapy, but severe side effects are also increased.”

“This trial provides clear evidence that the addition of chemotherapy after chemoradiation does not extend survival,” ASCO President Lori J. Pierce, MD, said in the press release. 2 “The results are immediately practice-changing, showing that this approach should not be used to treat locally advanced cervical cancer. We can now spare our patients the side effects and toxicity that comes with additional chemotherapy.”

Disclosures: This research was supported by the National Health & Medical Research Council of Australia. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Read more of Cancer Therapy Advisor’s coverage of the 2021 ASCO Annual Meeting by visiting the conference page.


  1. Mileshkin L, Moore KN, Barnes EH, et al. Adjuvant chemotherapy following chemoradiation as primary treatment for locally advanced cervical cancer compared to chemoradiation alone: The randomized phase III OUTBACK Trial (ANZGOG 0902, RTOG 1174, NRG 0274). J Clin Oncol .2021;39:(suppl 15; abstr LBA3). doi:10.1200/JCO.2021.39.15_suppl.LBA3
  2. Additional Chemotherapy Does Not Offer Survival Benefit for Patients With Locally Advanced Cervical Cancer. [press release]. Alexandria, VA: American Society of Clinical Oncology; June 3, 2021.