Predicting the effect of accelerated fractionation in postoperative radiotherapy for head and neck cancer based on molecular marker profiles: data from a randomized clinical trial.

PURPOSE: To determine the prognostic and predictive values of molecular marker expression profiles based on data from a randomized clinical trial of postoperative conventional fractionation (p-CF) therapy versus 7-day-per-week postoperative continuous accelerated irradiation (p-CAIR) therapy for squamous cell cancer of the head and neck. METHODS AND MATERIALS: Tumor samples from 148 patients (72 p-CF and 76 p-CAIR patients) were available for molecular studies. Immunohistochemistry was used to assess levels of EGFR, nm23, Ki-67, p-53, and cyclin D1 expression. To evaluate the effect of fractionation relative to the expression profiles, data for locoregional tumor control (LRC) were analyzed using the Cox proportional hazard regression model. Survival curves were compared using the Cox f test. RESULTS: Patients who had tumors with low Ki-67, low p-53, and high EGFR expression levels and oral cavity/oropharyngeal primary cancer sites tended to benefit from p-CAIR. A joint score for the gain in LRC from p-CAIR based of these features was used to separate the patients into two groups: those who benefited significantly from p-CAIR with respect to LRC (n = 49 patients; 5-year LRC of 28% vs. 68%; p = 0.01) and those who did not benefit from p-CAIR (n = 99 patients; 5-year LRC of 72% vs. 66%; p = 0.38). The nm23 expression level appeared useful as a prognostic factor but not as a predictor of fractionation effect. CONCLUSIONS: These results support the studies that demonstrate the potential of molecular profiles to predict the benefit from accelerated radiotherapy. The molecular profile that favored accelerated treatment (low Ki-67, low p-53, and high EGFR expression) was in a good accordance with results provided by other investigators. Combining individual predictors in a joint score may improve their predictive potential.

Randomized clinical trial on 7-days-a-week postoperative radiotherapy for high-risk squamous cell head and neck cancer.

PURPOSE: To evaluate the normal tissue reactions and loco-regional control rates (LRC) in patients treated with 7-days-a-week postoperative continuous irradiation (p-CAIR) compared to conventionally fractionated 5-days-a-week postoperative radiotherapy (CF). MATERIALS/METHODS: Between 2001 and 2004, 279 patients with high-risk squamous cell cancer of the larynx (158 pts.) or cancer of the oral cavity/oropharynx (121 pts.) were enrolled. They were stratified according to the primary cancer site (larynx vs. others) and the treating center and randomized to receive 63 Gy in fractions of 1.8 Gy given 5-days-a-week (140 pts: CF) or 7-days-a-week (139 pts: p-CAIR). RESULTS: The acute and late toxicity was considered acceptable, although the proportion of patients with confluent mucositis was higher in p-CAIR compared to CF (60.0 vs. 33.3%). The actuarial 3-year LRC were 64 vs. 70% for CF and p-CAIR, respectively, p=0.32. A statistically significant improvement in 3-year LRC in p-CAIR arm appeared in a subset of the patients with cancer of the oropharynx/oral cavity (74% p-CAIR vs. 53% CF, p=0.02). By contrast, there was no improvement in LRC in a subset of the patients with cancer of the larynx (p=0.46). CONCLUSION: An improvement in LRC attributable to acceleration of postoperative radiotherapy appeared restricted to the patients with cancer of the oropharynx/oral cavity. In patients with cancer of the larynx acceleration of postoperative radiotherapy did not have any beneficial effect.

Randomized clinical trial on continuous 7-days-a-week postoperative radiotherapy for high-risk squamous cell head-and-neck cancer: a report on acute normal tissue reactions.

BACKGROUND AND PURPOSE: To analyse acute mucosal reactions in patients treated with continuous accelerated postoperative irradiation (p-CAIR) compared to conventionally fractionated postoperative radiotherapy (p-CF). PATIENTS AND METHODS: The patients were randomly assigned to receive 63 Gy in 1.8 Gy fractions 7-days-a-week given over a period of 5 weeks (n=88), or 63 Gy in 1.8 Gy fractions given 5-days-a-week over 7 weeks (n=87). It represents 65% of an overall trial size. Acute mucosal reactions were scored using modified Dische system. Polychotomous logistic regression was used to estimate the influence of the selected variables on maximum grade of mucositis, and percent of the body weight loss during radiotherapy. RESULTS: The average maximum Dische score and percent of the patients with confluent mucositis were higher in patients treated with p-CAIR, compared to p-CF (13.3 vs. 10.8 and 54 vs. 27%). Polychotomous logistic regression analysis revealed that fractionation scheme and tumour site have significantly influenced maximum Dische score. Tumour site (laryngeal vs. other) had even stronger influence on maximum Dische score than fractionation scheme. The average residual Dische score 8 weeks after radiotherapy was higher in p-CAIR compared to p-CF (2.1 vs. 1.4), and was, most frequently, related to persistent mucosal erythema (70 vs. 57% of pts.). No severe consequential toxicity of radiotherapy was observed, so far, in the trial. CONCLUSIONS: While the incidence, intensity and duration of mucosal reactions was higher in p-CAIR than in p-CF the accelerated treatment can be considered tolerable with respect to acute toxicity. In both arms of the trial slight or moderate mucosal erythema was the most frequent acute side effect, which did not completely subside within 8 weeks after irradiation.