Revista de ensayos clínicos sobre el cáncer

Adjuvant Therapy for Resected Exocrine Pancreatic Cancer by Half-Body Low-Dose Irradiation

Abstract

Jerry M. Cuttler, Philippe Garzon, Ron E. J. Mitchel, Ludwig E. Feinendegen, Kiyohiko Sakamoto and James S. Welsh

After surgery, pancreatic cancer has an extremely high rate of systemic recurrence and a very high rate of local recurrence, more than 80 percent and 20 percent, respectively. Conventional adjuvant therapy prolongs median survival, 28 versus 15 months, by eliminating many of the metastases before they grow into new tumours. In an effort to improve outcomes, the authors recommend evaluating half-body low-dose irradiation (HB LDI) therapy because limited clinical studies have shown HB LDI to be successful as an adjuvant treatment for different types of cancer. Each dose fraction in LDI therapy is 15 cGy, about 13 times below the 200 cGy dose fraction employed in each normal (high-dose) radiation treatment to destroy cancer cells. The LDI mechanism is stress-related repeated stimulation of the patient's very powerful adaptive protection systems by repeated exposure of the patient's upper body to a low dose of radiation. Five weeks of applying this repetitive stress to the patient appears to prolong the enhanced cancer-cell-killing and tissue repair for many months. A booster of this treatment after six months would extend the stimulation for years. This therapy can be started immediately after surgery because it also promotes tissue healing and has no adverse symptomatic side effects. Since adjuvant chemotherapy would normally start within four to six weeks after resection, there is little risk of a delay in providing HB LDI therapy and evaluating its benefit. In most cases the serum marker CA 19-9 can be monitored. If the effectiveness of this therapy is judged to be inadequate, then conventional adjuvant therapies would be provided.