Concurrent RT With 5-FU/Epirubicin and Cisplatin or Irinotecan for Locally Advanced Upper GI Adenocarcinoma

Upper gastrointestinal (GI) cancers are a group of common and highly virulent diseases that include esophageal, gastric, pancreatic, and biliary tract cancers. Based on the American Cancer Society's estimates, there will be 14,250 esophageal, 22,710 gastric, and 31,860 pancreatic cancers diagnosed in 2004 in the United States.[1] The majority of patients present with advanced disease, and the prognosis for all sites is poor. Even for patients with resected disease, the rate of recurrence-including local failure and distant metastasis- is very high. Improvement in survival will rely on the development of effective multimodality treatment plans. Although recently developed chemotherapy regimens have shown some improvement in the treatment of advanced upper GI adenocarcinoma, most have only modest clinical efficacy. Combined chemotherapy and radiotherapy has demonstrated survival benefits in patients with locally advanced unresectable adenocarcinomas of the esophagus, gastroesophageal junction, stomach, and pancreas.[2-4] Survival advantages have also been shown with chemoradiation in the perioperative setting in upper GI cancers.[ 5-7] Infusional fluorouracil(Drug information on fluorouracil) (5-FU) concurrent with radiation has been accepted as the standard treatment for locally advanced upper GI adenocarcinomas. Epirubicin(Drug information on epirubicin) (Ellence) is a semisynthetic derivative of doxorubicin(Drug information on doxorubicin). The antitumor activity of epirubicin, like that of other anthracyclines, is thought to result from intercalation between DNA base pairs and stabilization of the topoisomerase II DNA complexes, leading to irreversible DNA strand breakage.[8] It has been estimated that epirubicin is about 75% as myelotoxic and 50% as cardiotoxic as doxoru bicin. Cisplatin(Drug information on cisplatin) is a heavy metal compound, which has the activity of a bifunctional alkylating agent and a broad spectrum of antitumor activity. The combination of 5-FU and cisplatin has been considered the reference regimen for advanced gastric cancer. The ECF regimen of epirubicin, cisplatin, and 5-FU has resulted in a significant response and survival benefit for advanced unresectable esophagogastric cancer.[9-12] Long-term follow-up of a prospectively randomized study demonstrated an advantage with the ECF combination compared with FAMTX (5-FU, doxorubicin [Adriamycin], methotrexate(Drug information on methotrexate)).[ 13] The overall response rate was 46% with ECF and 21% with FAMTX; the median survival was 8.7 vs 6.1 months; and the 2-year survival was 14% vs 5%. Preliminary results of a phase III study showed that pre- and postoperative ECF increases the rate of complete resection of locally advanced gastric cancer.[14] The study also demonstrated improved disease-free survival in patients who had ECF treatment before and after surgery, compared to those who had surgery alone. Although the study has not shown the survival benefit of perioperative ECF treatment, disease-free survival is improved in the ECF treatment arm. Re sults from several phase II studies suggest that ECF may prolong survival in patients with locally advanced or metastatic pancreatic cancer with tolerable toxicities.[15,16] Irinotecan(Drug information on irinotecan) (Camptosar), a camptothecin derivative, is a topoisomerase I inhibitor that traps the topoisomerase I/DNA cleavable complex following cleavage of single-strand DNA. Collision of the replication fork converts the single-strand break into a doublestrand break, thus inducing apoptosis. The antitumor activity of irinotecan has been well documented in colorectal cancer.[17] In upper GI malignancies, irinotecan has shown significant activity as a single agent[18] and also in combination with 5-FU.[19] In vitro and animal studies with epirubicin and camptothecins have demonstrated synergistic antitumor activity with enhanced DNA damage and tumor cell killing.[20] A recent randomized study compared concurrent chemoradiation with epirubicin (60 mg/m²) and externalbeam radiotherapy (40 Gy in fractions of 2.5 Gy four times a week for 4 consecutive weeks) to radiation alone in 220 patients with locally advanced cervical cancer.[21] The result demonstrated a survival benefit in the chemoradiation arm, with increased mild to moderate marrow suppression (no grade 4 leukopenia or grade 3 thrombocytopenia). There was no difference in treatment delays observed between the two arms, and no increased skin or normal organ toxicity. Therefore, the combination of radiotherapy with ECF (epirubicin, cisplatin, and 5-FU) or EIF (epirubicin, irinotecan, and 5-FU) chemotherapy for treatment of locally advanced upper GI adenocarcinoma holds promise. Ongoing Phase I Studies We are conducting two open-label phase I studies to evaluate concurrent, ascending doses of the combination of ECF or EIF with concurrent radiation when administered to patients with locally advanced upper GI adenocarcinoma. The primary end points are to find the dose for a phase II study, dose-limiting toxicity, and maximum tolerable dose. The response of these two combinations will also be determined for those patients with measurable or evaluable diseases. Trial Design Fluorouracil is administered as a continuous intravenous infusion via a Port-a-Cath through a portable infusion pump for 5.5 weeks during radiation treatment. Epirubicin and cisplatin or irinotecan is administered as a 60- to 90-minute infusion weekly for 5 weeks; administration is started on day 1 of radiation (days 1, 8, 15, 22, and 29 of the treatment plan) (Figure 1). All patients undergo treatmentplanning computed tomography and simulation. For nutritional support, most patients have feeding tubes (either G- or J-tubes) placed during chemoradiation treatment. Patients with histologically confirmed adenocarcinoma of the esophagus, stomach (including gastroesophageal junction), pancreas, and biliary tract, which is locally advanced unresectable or in whom postsurgery pathology showed positive margins, or with gross regional residual disease, are eligible for these two studies. Patients with adenocarcinoma of the esophagus, pancreas, and biliary tract status postresection and who are considered to have a high risk of recurrence (T3, T4, and/or lymph node metastases) are also acceptable. They should be older than 18 years old with relatively good overall performance status and reasonable liver and kidney function, with a left ventricular ejection fraction of at least 50%. Patients who had previous chemotherapy or radiation treatment are not qualified for either trial. Formal consent forms are signed by all patients undergoing treatment. The dose-escalation schedules of the studies are listed in Tables 1 and 2. Dose-limiting toxicities attributed to the study are defined as toxicities related to the treatment requiring discontinuation or significant dose reduction in study drugs. Toxicities are to be assessed according to the National Cancer Institute Common Toxicity Criteria scale. The maximum tolerated dose is defined as one dose level below the dose that induced dose-limiting toxicity in greater than one-third of patients in a given cohort. The dose modification is designed based on the type (hematologic vs nonhematologic) and grade of toxicities a patient may have. Results Both trials are at level 2 of their dose-escalating schedules. To date, there have been seven patients enrolled to the ECF trial and eight patients to the EIF trial. The characteristics of those patients are listed in Tables 3 and 4. Neutropenia, thrombocytopenia, nausea, vomiting, and diarrhea/dehydration are the main treatment-related toxicities for both trials. In the ECF trial, there was no doselimiting toxicity at level 1. One patient developed grade 3 dehydration at level 2 of the study, which is considered a dose-limiting toxicity. Three more patients will be added on that level for further evaluation. In the EIF trial, a 79-year-old patient with locally advanced biliary cancer at level 1 developed severe diarrhea (grade 3) and dehydration (grade 4) after her third dose of chemotherapy. She did not follow medical advice and was then admitted to the intensive care unit. She recovered from the event and was taken off study. Because of this case, four extra patients were added to that level, and no dose-limiting toxicity has been reached. There has been one patient enrolled on level 2, and so far there is no dose-limiting toxicity reported. There are three cases of Port-a- Cath-related upper extremity deepvein thrombosis in the EIF trial (two in level 1 and one in level 2), but not in the ECF trial. Although antitumor efficacy is not the primary end point of either trial, preliminary data are encouraging. In the ECF trial, among five enrolled locally advanced pancreatic cancer patients (three with unresectable disease and two with locally advanced disease post-operations), two patients had their diseases stabilized with de- creasing CA 19-9 and one patient achieved at least minimal response with normalized CA 19-9. One patient with T4, N1 duodenal adenocarcinoma, which was considered unresectable from prechemoradiation assessment, had curative surgical resection after treatment. The final pathology suggested that the disease was downstaged to T3, N0. The patient then had three more treatments of infusional 5-FU and cisplatin after surgery. There is still no evidence of disease. Another patient with a T3, N2 adenocarcinoma of gastroesophageal junction had his disease completely resected after therapy. In the EIF trial, all seven evaluable patients-including three cases of locally advanced pancreatic cancer, three cases of unresectable locally advanced cholangiocarcinoma, and one patient with T3, N2 gastroesophageal junction adenocarcinoma-achieved at least stable disease. The patient with gastroesophageal junction adenocarcinoma had complete surgical resection for his disease. Conclusion/ Both trials are actively ongoing, and no maximum tolerated dose has been reached.