Additional chemotherapy does not offer survival benefit for patients with locally advanced cervical cancer

Priscilla Lynch presents a round-up of some of the most topical research presented at this year’s ASCO Annual Meeting

Additional chemotherapy given after standard chemoradiation treatment does not improve survival for women with locally advanced cervical cancer, and is associated with additional side-effects, according to results of a phase 3 international trial presented at the 2021 ASCO Annual Meeting.

The findings are likely to immediately change practice for early adopters, who had hoped the regimen would reduce distant disease recurrence in patients. The standard treatment for locally advanced cervical cancer is chemoradiation with cisplatin-based chemotherapy concurrent with radiation. Yet a significant percentage of patients still relapse and die as a result of distant metastatic disease.

Because carboplatin and paclitaxel chemotherapy after chemoradiation are active initial treatments for the metastatic and relapsed setting and are successfully used as adjuvant therapy for other cancers – some oncologists routinely treat women with locally advanced cervical cancer with the regimen. However, until now, there has been no evidence from a large phase 3 study for or against the addition of chemotherapy in this setting.

The phase 3 OUTBACK trial of 919 patients with locally advanced cervical cancer, randomly assigned to receive standard cisplatin-based chemoradiation with or without additional chemotherapy with carboplatin and paclitaxel, demonstrated that chemotherapy following chemoradiation did not improve survival over standard chemoradiation alone.

At five years, OS was comparable for both groups – 72 per cent versus 71 per cent respectively, for those receiving adjuvant chemotherapy and those receiving standard care. Also, at five years progression-free survival (PFS) was 63 per cent in patients who received the additional treatment, compared with 61 per cent who did not. Patterns of disease recurrence were similar in the two treatment groups.

Serious adverse events (grade 3-5) were experienced by more patients up to one year after randomisation – 81 per cent of patients in the adjuvant chemotherapy group compared with 62 per cent in the standard treatment group. “The study confirms that chemoradiotherapy alone is currently our best possible treatment for women with locally advanced cervical cancer. Not only is there no benefit with adjuvant chemotherapy, but severe side-effects are also increased,” said lead author Dr Linda R Mileshkin, Medical Oncologist, Peter McCallum Cancer Centre, Melbourne, Australia.