THE PREDICTIVE VALUE OF TUMOR-REGRESSION RATES DURING CHEMORADIATION THERAPY IN PATIENTS WITH ADVANCED HEAD AND NECK SQUAMOUS-CELL CARCINOMA

OBJECTIVE: The Value of tumor regression rates in predicting survival outcome during chemoradiation therapy was prospectively evaluated. MET HODS AND MATERIALS: Sixty-two patients diagnosed with focally advanced stage III/IV unresectable head and neck squamous cell carcinoma under went weekly clinical and endoscopic serial assessment of primary and n odal tumor sizes during chemoradiation therapy between July 1993 and S eptember 1995. Chemoradiation therapy consisted of protocol treatment using supradose intra-arterial targeted cisplatin (SIT-P) at 150 mg/m( 2) four times at weekly intervals along with intravenous sodium thiosu lfate at 9 g/m(2) and concurrent conventionally fractionated radiother apy at 1.8 to 2.0 Gy/fraction (fx) to a total dose of 68 to 74 Gy. Tum or reduction was serially measured as a percentage of the original pre treatment size at weekly intervals by the same team of surgical and ra diation oncologists. Correlations were then made between tumor regress ion rates and survival. RESULTS: Complete or near complete regression of disease during chemoradiation therapy as compared with nonresponsiv e/partially responsive disease was associated with better survival out come (P = 0.001 and P = 0.013, respectively). Among patients exhibitin g complete or near complete regression of disease, rapid tumor reducti on (median = 4.2 weeks) was associated with inferior survival outcome when compared with slower disease regression (median = 6.4 weeks, P = 0.007). CONCLUSIONS: Our findings fail to support the ''traditional'' hypothesis that rapid tumor regression during treatment is predictive of an improved survival outcome. Treatment strategies that alter ongoi ng therapy based upon initial tumor regression rates should be avoided . (C) 1997 by Excerpta Medica, Inc.