Abstract: | The correlation between intralesional 5-FU concentrations and the extent of antitumor effect with particular attention to histopathology was assessed in 30 patients with breast cancer. Therapy consisted of either UFT or FT-207 given preoperatively. Although the UFT-treated group showed a significantly higher intratumoral concentration of 5-FU, there was no intergroup difference in 5-FU levels in normal tissue. In addition, this greater concentration of intratumoral drug had no significant effect on therapeutic response; for both UFT and FT-207 treated groups, the histologic interpretation was rated as grade IIa. Regardless of which drug was used, when tumors were stratified according to histologic type, papillotubular carcinomas revealed the greatest tissue 5-FU levels. However the greatest histologic antitumoral responses were seen in scirrhous carcinomas; hence no correlation was seen here either. The results suggest that attainment of a high intratumoral 5-FU concentration is not reflected in a better histologic tumor response in patients receiving the above drug regimens. |