Investigators have discovered that cetuximab in addition to concurrent radiotherapy may be safe and effective at treating patients with locally advanced cutaneous squamous cell carcinoma, according to a recent study published by Chang et al in Oncotarget.
Treatment for locally advanced cutaneous squamous cell carcinoma remains poorly defined. Most of these tumors express high levels of epidermal growth factor receptors (EGFR). Cetuximab has previously shown the potential for activity in other EGFR-expressing cancer types and is capable of enhancing the efficacy of radiotherapy.
Study Methods and Results
In the new study, the investigators conducted a retrospective review of institutional data and identified 18 patients with locally advanced cutaneous squamous cell carcinoma who received cetuximab induction and concurrent radiotherapy.
“We performed a retrospective review of treatment outcomes and toxicities … to show an additional potentially effective treatment option for patients with [the disease]. The goal [of our research was] also to provide data to inform the design of potential prospective clinical trials,” emphasized the study authors.
The investigators noted that an intravenous loading dose of 400 mg/m² of cetuximab was administered. Subsequent weekly intravenous doses of 250 mg/m² were infused while the patients were receiving radiotherapy. Additionally, the treatment doses ranged from 4,500 to 7,000 cGy, with a dose fraction of 200 to 250 cGy.
The investigators found that the objective response rate was 83.2%—with 55.5% complete responses and 27.7% partial responses among the patients who received the treatment regimen.
Median progression-free survival was 21.6 months. After a follow-up of 1 and 2 years, the investigators demonstrated that the patients experienced a progression-free survival rate of 61% and 40%, respectively. With longer follow-up, some patients developed a local recurrence (16.7%), distant metastases (11.1%) or a second primary cancer (16.3%).
Cetuximab was well tolerated, with 68.4% of patients experiencing only mild acneiform skin rashes or grade 1 or 2 fatigue. Radiotherapy produced expected side effects—such as skin erythema, moist desquamation, and mucositis.
Conclusions
“Cetuximab plus radiotherapy represents an active and tolerable treatment option for [patients with locally advanced cutaneous squamous cell carcinoma], including patients with contraindications for checkpoint inhibitor therapy,” the study authors concluded.
Disclosure: For full disclosures of the study authors, visit oncotarget.com.
