EMD-55900

Feline oral squamous cell carcinoma (FOSCC) is characterised by invasive and metastatic behaviour and is poorly responsive to current treatments, hence the need for new therapeutic strategies. FOSCC shares molecular targets with human head and neck squamous cell carcinoma (HNSCC), among these the epidermal growth factor receptor. Cetuximab is an anti‐epidermal growth factor receptor monoclonal antibody employed in the therapy of HNSCC and, interestingly, previous work in vitro suggested that it displays cytostatic and cytotoxic properties also against FOSCC. With the present study, we aimed at further investigating the effects of cetuximab on invasion and metastasis pathways proven to be relevant in human patients. To this purpose, FOSCC cell lines SCCF1, SCCF2 and SCCF3 were treated with cetuximab for 48/72 h and subjected to Western blot for matrix metalloproteinases‐2/9 (MMP‐2/9) and epithelial–mesenchymal transition markers vimentin, E‐, P‐ and N‐cadherin. Treatment with cetuximab resulted in downregulation of MMP‐2/‐9 in all of the three cell lines in a dose‐dependent manner. Moreover, cetuximab downregulated vimentin and P‐cadherin in SCCF1, upregulated E‐cadherin whilst downregulating P‐/N‐cadherins in SCCF2, and impaired P‐/N‐cadherins in SCCF3. An in vitro scratch test also demonstrated that cetuximab delayed cell migration in SCCF3. These data suggest that cetuximab mitigates invasion and metastasis processes by impairing MMPs and epithelial–mesenchymal transition pathways in FOSCC, indicating that this monoclonal antibody may help to counteract malignant progression and improve the management of locally invasive disease.

Anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibodies are effective in treating RAS wild-type metastatic colorectal cancer (mCRC). However, their administration induces skin toxicity, markedly reducing patients' quality of life. This study is aimed at identifying the risk factors associated with anti-EGFR monoclonal antibody-induced skin toxicities.

Patients with mCRC (n = 116) who received anti-EGFR monoclonal antibody treatment were retrospectively evaluated. Primary endpoint was evaluation of the risk factors for grade ≥ 2 overall skin toxicities during all the treatment periods. Furthermore, factors associated with each grade ≥ 2 skin symptoms were assessed.

Incidence of total grade ≥ 2 skin toxicity symptoms was 61.2%, and those of grade ≥ 2 rash, dry skin, fissures, and paronychia were 34.5%, 25.9%, 20.7%, and 25.0%, respectively. Multivariate logistic regression analyses revealed that liver metastasis was an independent risk factor for overall grade ≥ 2 skin toxicities (adjusted odds ratio [OR], 2.88; 95% confidence interval [CI], 1.22-6.78; P = 0.02) and prophylactic administration of antibiotics as a preventive factor (OR 0.10; 95%CI 0.01-0.91; P = 0.04). For grade ≥ 2 rash, prophylactic use of systemic antibiotics and topical steroid ointment was a preventive factor (OR 0.37; 95%CI 0.16-0.89; P = 0.03). Moreover, liver metastasis (OR 8.37; 95%CI 1.98-35.47; P = 0.004) and prophylactic administration of antibiotics (OR 0.15; 95%CI 0.03-0.76; P = 0.02) were significantly associated with grade ≥ 2 paronychia.

Liver metastasis was suggested to be a risk factor for the incidence of overall grade ≥ 2 skin toxicities; moreover, preemptive systemic antibiotic administration drastically decreased this risk during all periods of anti-EGFR treatment for mCRC.