Intensity-Modulated Radiation Therapy Reduces PEG Tube Dependence and Severe Skin and Mucous Membrane Toxicity in Oropharyngeal Cancer
In a single-center experience reported in JAMA Otolaryngology-Head & Neck Surgery, Lohia et al found that intensity-modulated radiation therapy for oropharyngeal cancer reduces percutaneous endoscopic gastrostomy (PEG) tube dependence and severe skin and mucous membrane toxicity compared with conventional three-dimensional (3D) conformal radiation therapy. No differences in weight loss, change in performance status, rates of treatment failure, or overall or disease-free survival were observed.
Study Details
The study was a retrospective review of 159 patients with primary oropharyngeal squamous cell carcinoma with no history of chemotherapy, radiation therapy, or surgery of the head and neck who underwent definitive treatment with intensity-modulated radiation therapy (n = 103) or 3D conformal radiation therapy (n = 56) at the Hollings Cancer Center outpatient clinic at Medical University of South Carolina from 2000 to 2009. All patients received radiotherapy doses of 70 Gy in 35 daily fractions.
Primary endpoints consisted of PEG tube dependence 1 year after start of radiotherapy, weight loss during treatment, and change in Eastern Cooperative Oncology Group (ECOG) performance status. Secondary endpoints included overall survival, disease-free survival, disease recurrence, and toxicity profiles.
In the intensity-modulated radiation therapy and 3D conformal radiation therapy groups, 92% and 89% received chemoradiotherapy and 91% and 89% had stage III or IV disease. In the intensity-modulated radiation therapy group, 22% of patients received cisplatin and paclitaxel, 37% cisplatin alone, 10% carboplatin plus paclitaxel, 2% carboplatin alone, 16% cetuximab (Erbitux), and 4% cisplatin plus erlotinib (Tarceva). In the 3D conformal radiation therapy group, 64% received weekly cisplatin and paclitaxel, 12% cisplatin, and 11% cisplatin with fluorouracil.
Primary Endpoints
PEG tubes were placed at the start of treatment in 61% of intensity-modulated radiation therapy patients and 79% of 3D conformal radiation therapy patients (P = .04), but more intensity-modulated radiation therapy patients had tube placement after the start of therapy (P = .009). At 1 year, 13% vs 35% of patients remained PEG tube–dependent (P = .02), including 12% vs 38% of those with stage III or IV disease (P = .01). Median duration of PEG tube dependence was 154 vs 259 days (P < .001).
There was no significant difference between the two groups in weight loss (P = .86), no correlation between PEG tube presence and degree of weight loss in either group, and no significant interaction for PEG tube presence during treatment and degree of weight loss within or between groups.
There was no significant difference between the intensity-modulated radiation therapy and 3D conformal radiation therapy groups in change in ECOG performance status (P = .42).
Secondary Endpoints
Grade ≥ 3 skin toxicity (7% vs 23%, P = .02) and mucous membrane toxicity (37% vs 76%, P < .001) were reduced with intensity-modulated radiation therapy. There were no differences between groups in toxicity scores for toxic effects to the salivary gland, pharynx, or larynx. During the treatment period, 2% vs 0% of patients died as a result of treatment-related toxic effects, 19% vs 30% required treatment-related hospitalization, and 6% vs 11% required treatment delay due to toxic effects, with no significant differences observed for these outcomes.
There was no significant difference between the intensity-modulated radiation therapy group and the 3D conformal radiation therapy group in median overall survival (34.8 vs 57.5 months, P = .45) or disease-free survival (32.4 vs 46.9 months, P = .26) or rates of disease recurrence (hazard ratio = 0.82, 95% confidence interval = 0.47–1.41). Median time to recurrence was 6.5 vs 13.0 months.
The investigators concluded, “The use of [intensity-modulated radiation therapy] significantly improves PEG tube and toxicity-related outcomes compared with [3D conformal radiation therapy] in the treatment of oropharyngeal primary cancers. Given the association between mucosal toxic effects, PEG tube dependence, and dysphagia, these findings may be an indication of improved swallowing outcomes with [intensity-modulated radiation therapy].”
Shivangi Lohia, MD, of the Medical University of South Carolina, is the corresponding author for the JAMA Otolaryngology-Head & Neck Surgery article.
The study authors reported no potential conflicts of interest.
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