64 Radiation Oncology ?? Biology ?? Physics October 1984, Volume 10, Sup. 2 306 CHEMOTHERAPY FOR RADIATION ONCOLOGISTS Stephen K. Carter Pharmaceutical Research and Development Division, Bristol-Myers Company Cancer Chemotherapy is a modality which can be curative or palliative depending upon the tumor in question, its stage and prior therapeutic history. One of the major hopes for increasing the curative potential of chemotherapy has been combining it with irradiation and/or surgery to attack micrometastatic disease. This has been called adjuvant chemotherapy. Despite initial enthusiasm and excitement adjuvant chemotherapy has been generally disappointing. The best data exist for Wilms' tumors, Ewing's sarcoma and embryonal rhabdomyosarcoma. The data for breast cancer and osteosarcoma are controversial and clearly at this time do not represent a major improvement in therapy. The data for gastrointestinal and lung cancer indicate no meaningful benefit. In the malignant lymphomas, where chemotherapy against microscopic disease is highly positive, adjuvant chemotherapy for early stage disease after curative intent irradiation has been equivocal at best. It therefore appears time to reevaluate the basic tenets of adjuvant chemotherapy as well as the design of future trials. New developments in cancer chemotherapy involve the search for new drugs, superior analogs of existing drugs, and ways of improving the therapeutic index. The preclinical evaluation of new drugs needs to be improved and systems developed which are more clinically relevant than the murine transplantable systems currently in use. One approach is to use human tumor related models in a related mixture of in vitro and in vivo systems. The clinical evaluation of new drugs is made difficult by the very success of chemotherapy which precludes utilizing the responsive tumors for new drug evaluation until after they have been heavily pretreated. Improving the therapeutic index involves increasing the dose of chemotherapy and/or diminishing the side effects. Approaches to increasing the dose include: bone marrow transplantation, targeting with monoclonal antibodies and regional drug delivery. The blocking of specific toxicities with biologic modifiers of drug action offer another opportunity for increasing drug dosage or at least making more tolerable the existing drug dosages. 307 SKIN CANCER AND ITS TREATMENT BY RADIOTHERAPY Peter J. Fitzpatrick, M.D. Princess Margaret Hospital, University of Toronto, Ontario The purpose of this refresher course is to provide the basic and clinical information necessary for the successful treatment of skin cancer by radiotherapy. Carcinomas of the skin are the commonest of all cancers. They are disfiguring but rarely fatal and can be managed in a variety of ways. Al ternat ives include surgery, radiation therapy, chemosurgery, cryotherapy, electrodesiccation and chemotherapy. The selection of optimal treatment is best made by a multidisciplinary oncologic team with decisions based on the probability of cure, cosmesis, function and relative comfort, time and cost of treatment. Basal and squamous cell carcinomas, melanoma, keratoacanthoma, Bowen’s disease and pre-malignant lesions will be reviewed . Special attention will be given to turnout-s at particular sites such as the eyelid, ear, nose and lip. The clinical aspects, technical details of radiotherapy, reactions, complications and results of treatment based on over 15,000 patients followed for a minimum of 8 years will be presented. For basal and squamous cell carcinomas treated by radiotherapy, the control rate is 95% and the cosmetic and functional results usually excellent.

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Page 1: Chemotherapy for radiation oncologists

64 Radiation Oncology ??Biology ??Physics October 1984, Volume 10, Sup. 2

306 CHEMOTHERAPY FOR RADIATION ONCOLOGISTS

Stephen K. Carter

Pharmaceutical Research and Development Division, Bristol-Myers Company

Cancer Chemotherapy is a modality which can be curative or palliative depending upon the tumor in question, its stage and prior therapeutic history. One of the major hopes for increasing the curative potential of chemotherapy has been combining it with irradiation and/or surgery to attack micrometastatic disease. This has been called adjuvant chemotherapy. Despite initial enthusiasm and excitement adjuvant chemotherapy has been generally disappointing. The best data exist for Wilms' tumors, Ewing's sarcoma and embryonal rhabdomyosarcoma. The data for breast cancer and osteosarcoma are controversial and clearly at this time do not represent a major improvement in therapy. The data for gastrointestinal and lung cancer indicate no meaningful benefit. In the malignant lymphomas, where chemotherapy against microscopic disease is highly positive, adjuvant chemotherapy for early stage disease after curative intent irradiation has been equivocal at best. It therefore appears time to reevaluate the basic tenets of adjuvant chemotherapy as well as the design of future trials.

New developments in cancer chemotherapy involve the search for new drugs, superior analogs of existing drugs, and ways of improving the therapeutic index. The preclinical evaluation of new drugs needs to be improved and systems developed which are more clinically relevant than the murine transplantable systems currently in use. One approach is to use human tumor related models in a related mixture of in vitro and in vivo systems. The clinical evaluation of new drugs is made difficult by the very success of chemotherapy which precludes utilizing the responsive tumors for new drug evaluation until after they have been heavily pretreated.

Improving the therapeutic index involves increasing the dose of chemotherapy and/or diminishing the side effects. Approaches to increasing the dose include: bone marrow transplantation, targeting with monoclonal antibodies and regional drug delivery. The blocking of specific toxicities with biologic modifiers of drug action offer another opportunity for increasing drug dosage or at least making more tolerable the existing drug dosages.

307 SKIN CANCER AND ITS TREATMENT BY RADIOTHERAPY

Peter J. Fitzpatrick, M.D.

Princess Margaret Hospital, University of Toronto, Ontario

The purpose of this refresher course is to provide the basic and clinical information necessary for the successful treatment of skin cancer by radiotherapy. Carcinomas of the skin are the commonest of all cancers. They are disfiguring but rarely fatal and can be managed in a variety of ways. Al ternat ives include surgery, radiation therapy, chemosurgery, cryotherapy, electrodesiccation and chemotherapy. The selection of optimal treatment is best made by a multidisciplinary oncologic team with decisions based on the probability of cure, cosmesis, function and relative comfort, time and cost of treatment. Basal and squamous cell carcinomas, melanoma, keratoacanthoma, Bowen’s disease and pre-malignant lesions will be reviewed . Special attention will be given to turnout-s at particular sites such as the eyelid, ear, nose and lip. The clinical aspects, technical details of radiotherapy, reactions, complications and results of treatment based on over 15,000 patients followed for a minimum of 8 years will be presented. For basal and squamous cell carcinomas treated by radiotherapy, the control rate is 95% and the cosmetic and functional results usually excellent.