Introduction/Background Definitive concurrent chemoradiation [dChR] is the standard treatment for locally advanced cervical cancer [LACC]. Although there’s insufficient clinical evidence to support it, induction chemotherapy [iChT] previous to dChR may reduce the tumour burden and improve symptoms. We evaluated the overall survival [OS] (primary outcome), the complete radiological response rate [CRRR] and the disease-free survival [DFS] (secondary outcomes) of the patients [pts] treated with iChT+dChR at our institution.

Methodology This is a Portuguese, single-centre, retrospective cohort study, including all LACC pts treated with QRTd between 2012 and 2019. The control group received dChR and the experimental group iChT+dChR. Standard uni/multivariate analyses were performed, with logistic regression models assessing the impact of iChT on CRRR, and Cox regression models for OS/DFS.

Results 57 pts (median age 53yo, 90% squamous cell carcinoma) were included; 1 with FIGO IB2 stage, 3 IB3, 1 IIA2, 28 IIB, 5 IIIB, 11 IIIC and 8 IVA; 45 were treated with dChR and 12 with iChT+dChR (carboplatin/paclitaxel, median 3 cycles). FIGO staging was higher in the iChT+dChR group (p<0.001). One patient progressed during iChT, and all others were treated with dChR (1 with carboplatin, 55 with cisplatin, median 6 cycles/66.6Gy); 39% were treated with brachytherapy boost [BT]. The response rate was evaluable in 51 pts (5 died before radiological evaluation and 1 was waiting for it at the time of inclusion). The CRRR was lower in the iChT+dChR group (42% vs 76%, p=0.03), but not after adjusting for age, FIGO stage and BT use (p=0.06). With a median follow-up of 49 months, 23 pts died (33% of the dChR group and 67% of the iChT+dChR group): 13 due to progression, 3 due to treatment complications (radiation enterocolitis, pelvic fistulization/abscess), and 7 due to other causes. In univariate analysis, both DFS (median 11.3 vs 80.2 months, HR 5.8, p<0.001) and OS (median 22.2 months vs NR, HR 3.4, p=0.006) were lower in the iChT+dChR group. In multivariate analysis, adjusting for age and FIGO stage, the difference remained significant on DFS (p=0.01) but not on OS (p=0.10).

Conclusion Pts treated with iChT had worse CRRR, DFS and OS compared with dChR alone, possibly due to selection bias caused by inclusion of pts with worse prognosis in the iChT group. Although our data does not support the addition of iChT to dChR in LACC pts, it may be considered in symptomatic pts, with urgent need for treatment.

Disclosures Pedro Simões (presenting author) has no potential conflicts of interest to declare.

João Godinho – Scientific Advisory Board: Grunenthal

Luísa Leal-Costa has no potential conflicts of interest to declare.

Mafalda Casa-Nova – Scientific Advisory Board: Roche, Pfizer, Merck; Honoraria received: AstraZeneca, Tesaro, Novartis

Fernando Igreja has no potential conflicts of interest to declare.

Gustavo Mendinhos has no potential conflicts of interest to declare.

Rosa Madureira has no potential conflicts of interest to declare.

Vanessa Monteiro has no potential conflicts of interest to declare.

Vera Mendonça has no potential conflicts of interest to declare.

José Luís Passos-Coelho – Advisory/consultancy: Roche, Novartis, AstraZeneca, Lilly; research Grant/Funding (self): Roche, Novartis