Volume 30, Issue 3 p. 621-627
Article
Free Access

Lung cancer: Clinical trial of radiotherapy alone vs. Radiotherapy plus cyclophosphamide

D. E. Bergsagel MD, DPHIL, FRCP(C)

Corresponding Author

D. E. Bergsagel MD, DPHIL, FRCP(C)

Chief of Medicine, The Princess Margaret Hospital, Toronto, Ontario, Professor of Medicine, The University of Toronto, Ontario

The Princess Margaret Hospital, 500 Sherbourne St., Toronto 284, Ontario, Canada===Search for more papers by this author
R. D. T. Jenkin MA, MB, FRCP(C), FFR

R. D. T. Jenkin MA, MB, FRCP(C), FFR

Staff Radiotherapist, The Princess Margaret Hospital, Toronto, Assistant Professor, Department of Radiology, University of Toronto

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J. F. Pringle MB, CHB, DMRT (EDIN), FFR

J. F. Pringle MB, CHB, DMRT (EDIN), FFR

Staff Radiotherapist, The Princess Margaret Hospital, Toronto; Associate, Department of Radiology, University of Toronto

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D. M. White MD, FRCP(C)

D. M. White MD, FRCP(C)

Clinical Assistant Professor of Medicine, University of Western Ontario

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J. C. M. Fetterly MD

J. C. M. Fetterly MD

Clinical Assistant Professor of Radiology, University of Western Ontario

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D. J. Klaassen BA, MD, FRCP(C)

D. J. Klaassen BA, MD, FRCP(C)

Lecturer in Medicine. University of Ottawa, Head, Section of Medical Oncology, Civic Hospital Division of Ottawa Cancer Clinic, and the Department of Medicine, Ottawa Civic Hospital

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R. S. R. McDermot BA, MD, CRCP(C)

R. S. R. McDermot BA, MD, CRCP(C)

Therapeutic Radiologist, The Ontario Cancer Foundation, Ottawa Clinic

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Abstract

Patients with non-resectable lung cancer confined to the central area of the thorax were randomly assigned treatment with radiotherapy to the primary lesion and mediastinum (group C), and radiotherapy plus either four (group B) or eight (group A) courses of high-dose intermittent cyclophosphamide. Cyclophosphamide therapy delayed the progression of metastatic lesions outside the irradiated field (median interval to progression 192 days for groups A and B vs. 114 days for group C), and prolonged survival (median 306 days for groups A and B vs. 216 days for group C). Assuming a tumor-doubling time of 18 days, the improved survival of the cyclophosphamide-treated patients could be explained by the inhibition of 90/18 = 5 tumor doublings or a tumor cell kill of 101,5. This result indicates that cyclophosphamide is only minimally effective in the treatment of lung cancer, but it is an active drug and it should be considered for inclusion in future trials of drug combinations.