COMBINED MODALITY THERAPY INCREASING LOCAL-CONTROL OF PANCREATIC-CANCER

Twenty patients with inoperable locally advanced Stage II and III panc reatic cancer were treated with combined modality therapy. Radiotherap y consisted of split courses of 2000 cGy each and, as needed, an addit ional 1400 cGy, separated by 2-week intervals. Simultaneous multidrug regimen chemotherapy consisted of 5-fluorouracil, continuous infusion, 1 g/m2 days 1-5; streptozotocin, 300-500 mg/m2 days 1, 2, 3; and cisp latin, 100 mg/m2 day 3 of every 4-week radiotherapy course (RT-FSP). P rimary tumors decreased more than 50% in volume in 11 of 20 patients. Computed tomography scans demonstrated apparent complete disappearance of the primary tumor in 7 patients. Only 3 patients had tumor regrowt h within the radiotherapy field, all after the end of radiotherapy. Lo cal control improved as measured by increased frequency of tumor shrin kage and decreased frequency of primary tumor growth, recognizing the limitations of a pilot study and comparisons to best historical result s achieved with standard short 5-fluorouracil schedules and radiothera py. Successful local control largely eliminates the most common cause of refractory pain and may decrease the need for some forms of early p alliative surgical intervention. Tumor shrink-age sometimes downstages tumors, creating frequent investigational opportunities for either el ective extirpative surgery or intraoperative radiotherapy. This pilot experience also supports testing of expanded eligibility staging crite ria for combined modality treatment and testing of new drugs as part o f 5-fluorouracil-radiotherapy-based regimens.