Improvement of human tumor cloning assay by suspension of fibroblasts into the bottom layer of agarose.

Twenty-nine human tumors were cultured on a soft agarose cloning assay under three conditions: (1) standard (control); (2) standard with varying numbers of mitomycin C-treated 3T3 Swiss mouse embryonic fibroblasts suspended into the bottom layer of agarose; and (3) standard with varying concentrations of conditioned medium derived from those same fibroblasts. Suspension of 1 X 10(5) fibroblasts into the bottom layer of agarose was found to significantly increase the number of colonies formed over control specimens, as did cultures with 30% conditioned medium. In addition, compared with control, both of these techniques increased the number of specimens which would allow optimal vitro chemotherapy sensitivity testing. Specifically, growth of at least 30 colonies per plate increased from 7% of specimens treated under control conditions to 36% and 52% of specimens treated with 30% conditioned medium and 1 X 10(5) fibroblast-supplemented agar, respectively. This data indicate that 3T3 Swiss mouse fibroblasts improve cloning efficiency when suspended in the bottom layer of agarose or when used to produce conditioned medium. As a consequence, these techniques may permit a better opportunity to define the role of the cloning assay for cancer chemotherapy.

Combined therapy for stage III-IV head and neck cancer: preliminary results.

As part of a combined modality treatment program using chemotherapy, surgery, and/or radiotherapy, 25 patients with previously untreated stage III or IV head and neck cancer received initial combination chemotherapy. Pathologically confirmed complete remission was noted in nine patients (36%). The overall objective major response rate (with all patients included in analysis) was 68%. The chemotherapy regimen included bleomycin, cisplatin, vinblastine, methotrexate, and 5-fluorouracil. A novel concept of drug scheduling was used, based on chemotherapy-induced improvement in RBC deformability. The underlying concept is that improved RBC deformability results in improved capillary blood flow and thereby, increased drug delivery to tumor cells. Treatment resulted in moderate hematologic and renal toxicity with no treatment-related deaths. This exceptionally high, pathologically confirmed complete response rate will hopefully provide a mechanism by which combined modality therapy can adequately be tested for its ability to prolong survival of patients with advanced head and neck cancer.