Induction chemotherapy followed by standard chemoradiotherapy versus standard chemoradiotherapy alone in patients with locally advanced cervical cancer (GCIG INTERLACE): an international, multicentre, randomised phase 3 trial

Background: Locally advanced cervical cancer is treated with chemoradiotherapy (standard of care), but many patients still relapse and die from metastatic disease. We investigated chemoradiotherapy with or without induction chemotherapy to determine whether induction chemotherapy improves both progression-free survival and overall survival. Methods: The INTERLACE trial was a multicentre, randomised phase 3 trial done at 32 medical centres in Brazil, India, Italy, Mexico, and the UK. Adults (aged ≥18 years) with locally advanced cervical cancer (FIGO 2008 stage IB1 disease with nodal involvement, or stage IB2, IIA, IIB, IIIB, or IVA disease) were randomly assigned (1:1), by minimisation, using a central electronic system, to standard cisplatin-based chemoradiotherapy (once-a-week intravenous cisplatin 40 mg/m2 for 5 weeks with 45·0–50·4 Gy external beam radiotherapy delivered in 20–28 fractions plus brachytherapy to achieve a minimum total 2 Gy equivalent dose of 78–86 Gy) alone or induction chemotherapy (once-a-week intravenous carboplatin area under the receiver operator curve 2 and paclitaxel 80 mg/m2 for 6 weeks) followed by standard cisplatin-based chemoradiotherapy. Stratification factors were recruiting site, stage, nodal status, three-dimensional conformal radiotherapy or intensity modulated radiotherapy, age, tumour size, and histology (squamous vs non-squamous). Primary endpoints were progression-free survival and overall survival within the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT01566240, and EUDRACT, 2011-001300-35. Findings: Between Nov 8, 2012, and Nov 17, 2022, 500 eligible patients were enrolled and randomly assigned to the chemoradiotherapy alone group (n=250) or the induction chemotherapy with chemoradiotherapy group. Of 500 patients, 354 (70%) had stage IIB disease and 56 (11%) stage IIIB disease. Pelvic lymph nodes were positive in 215 (43%) patients. 230 (92%) patients who received induction chemothera