Combined Chemotherapy-Radiation Therapy for Lung Cancer
スポンサーリンク
概要
- 論文の詳細を見る
From the above it is clear that a great many variables, unrelated to treatment efficacy, might affect the outcome of a combined chemotherapy- radiation therapy clinical trial. It is also evident that there is no compelling reason for choosing any particular design. The best option at this time might be to design studies that seek to define optimal ways to combine chemotherapy and radiation therapy. This information will be especially important as new, more active, chemotherapy regimens are discovered. I propose that a major factor causing poor treatment results in lung cancer and in other solid tumors is poor tumor blood supply and poor tumor blood flow. It is known that tumor tissue is hypoxic and acidotic. There are at least 3 causes ; 1) a decrease in number of blood vessels per unit area of tumor, 2) vascular compression caused by pressure related to tumor growth in a relatively confined space, and 3) rheologic disturbances in blood flow through cancers produced by increased plasma viscosity and decreased flexibility of circulating blood cells. lmpaired microcirculatory blood flow in cancer causes radiation resistance because of hypoxia and may cause chemotherapy resistance by preventing drugs from reaching cancer cells in adequate concentration and for adequate time. How might this condition be improved ? With regard to drug delivery to cancer it has been demonstrated, in animal models, that radiation therapy will increase vascular permeability in tumor tissue. Increased vascuhr permeability may allow higher concentrations of chemotherapy drugs to reach cancer cells. This, if true in humans, might be a rationale for starting treatment with radiation therapy. Other laboratory and clinical studies that I have conducted suggest that chemotherapy can correct some of the above mentioned rheologic disturbances. The laboratory parameter studied was flow of red blood cells or whole blood through filters with 3 micron or 5 micron diameter pores. In a study of patients with advanced, unresectable squamous cell lung cancer if a majority of chemotherapy was administered at a time when red blood filterability was improved by prior chemotherapy adninistraticn an 85% response rate was achieved (15% complete). These findings suggest that chemotherapy might be started first with radiation therapy beginning several days later. I am currently evaluating whether radiation therapy also increases blood filterability. If so patients might be started on radiation therapy with chemotherapy administered at the time of maximal improvement. This data will be reported.
- 日本肺癌学会の論文
- 1991-10-01