ESMO Congress 2024 | OncologyPRO

Abstract 862P

Background

Surgery remains the only curative treatment for locally advanced oral cavity squamous cell carcinoma (OCSCC). For ‘Borderline resectable’ OCSCC, conversion to surgery has shown improved outcomes, but historical induction chemotherapy (IC) yields a mere 40% conversion rate. Addition of targeted agents like cetuximab has not yielded satisfactory outcomes. We report our outcomes with multi-agent IC in combination with low-dose nivolumab (LD-Nivo) for this clinical setting.

Methods

We prospectively enrolled 28 (26 male, 2 female) patients (pts) with OCSCC between April 2023 and March 2024, deemed ‘Borderline Resectable’ per pre-defined criteria in the Head and Neck Multidisciplinary Tumor Board (MDT). All pts received nab-paclitaxel 175mg/m², carboplatin AUC 5, LD-Nivo (20mg or 40mg based on weight) along with triple oral metronomic therapy - Erlotinib 100mg OD, Celecoxib 200mg BD and 9mg/m² weekly Methotrexate. After two 21-day cycles, reassessment imaging was discussed in MDT for feasibility of resectability. The primary endpoint was the proportion of pts undergoing R0 resection after two cycles of planned induction therapy. Secondary endpoints were objective response rates (ORR) and adverse events (AE).

Results

Baseline characteristics and AE are tabulated. ORR was 66.6% (18 partial response, 9 stable disease). One pt withdrew consent after cycle 1. After 2 cycles, 21/27 (77.7%) pts underwent surgery, all were R0 resection. Three pts (11.1%) had a pathological complete response. All 21 pts received adjuvant concurrent chemoradiation with weekly cisplatin. At a median 7.4 months follow-up, one pt had progression in lung. There were no treatment-related deaths. Table: 862P

Baseline characteristics and AE

PARAMETER	VALUE
Median (IQR) Age	44 (39-54)
PRIMARY SITE Buccal mucosa Oral tongue	16 11
BORDERLINE RESECTABILITY CRITERIA 1. Buccal mucosa primary with diffuse margins and peritumoral edema going up to the level of sigmoid notch of mandible but not above 2. Oral tongue primary with extension to posterior one-third of tongue or floor of mouth	16 11
STAGE III IVA IVB	1 11 15
GRADE 3 AE Anaemia Thrombocytopenia Infections Diarrhea Febrile neutropenia Acneiform rash	3 3 3 2 1 1
Grade 4 Acute Kidney Injury	1
IMMUNE-RELATED AE Grade 2 polyarthritis Reactivation of tuberculosis	1 1

Conclusions

Preoperative multi-agent IC + LD-Nivo is feasible with a manageable safety profile. It has higher conversion rates to surgery than historical IC for ‘Borderline resectable’ OCSCC.