In an Australia-New Zealand phase III trial (Trans Tasman Radiation Oncology Group 05.01) reported in the Journal of Clinical Oncology, Porceddu et al found no benefit of adding carboplatin to postoperative radiation therapy in patients with high-risk cutaneous squamous cell carcinoma of the head and neck.
In the open-label trial, 310 patients from 22 sites in Australia and New Zealand were randomized between April 2005 and July 2014 to receive radiotherapy alone at 60 Gy in 30 fractions or 66 Gy in 33 fractions over 6 or 6.5 weeks (n = 157) or with weekly carboplatin (area under the curve = 2) starting on day 1, 2, or 3 of the radiotherapy and repeated on the same day each week to a maximum of 6 doses (n = 153).
The primary endpoint was freedom from locoregional relapse. Overall, 77% of patients had high-risk nodal disease; 19%, high-risk primary or in-transit disease; and 4%, both.
Locoregional Relapse and Survival Outcomes
Median follow-up was 60 months. Rates of freedom from locoregional relapse in the chemoradiotherapy vs radiotherapy groups were 89% vs 88% at 2 years and 87% vs 83% at 5 years (hazard ratio = 0.84, P = .58). Locoregional failure was the most common site of first treatment failure, with isolated distant metastases observed as the site of first failure in 7% of both groups. Disease-free survival was 83% vs 78% at 2 years and 73% vs 67% at 5 years (HR = 0.85, P = .44). Overall survival was 88% vs 88% at 2 years and 79% vs 76% at 5 years (HR = 0.95, P = .86).
The most common grade 3 or 4 adverse events in the chemoradiotherapy and radiotherapy groups were dermatitis (38% vs 49%) and mucositis (11% vs 10%). Any grade nausea occurred in 57% (55% grade 1 or 2) of the chemoradiotherapy group. Any grade constipation (21% vs 1%, P < .001), fatigue (26% vs 4%, P < .001), and dysgeusia (13% vs 5%, P = .018) were significantly more common in the chemoradiotherapy group. Grade 3 or 4 late toxicities were infrequent, with the most common being xersostomia (2% of radiotherapy group) and induration/fibrosis (2% of radiotherapy group).
The investigators concluded, “Although surgery and postoperative [radiotherapy] provided excellent [freedom from locoregional relapse], there was no observed benefit with the addition of weekly carboplatin.”
The study was supported by the National Health and Medical Research Council-Australian Government, Cancer Council Queensland, Queensland Government, and Cancer Australia.
Sandro Virgilio Porceddu, MD, of Princess Alexandra Hospital, Brisbane, is the corresponding author for the Journal of Clinical Oncology article.
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