Wolf Achterrath

Irinotecan in the Treatment of Colorectal Cancer: Clinical Overview

PURPOSE AND METHODS For more than three decades, the therapeutic options for patients with advanced colorectal cancer have almost exclusively been based on fluoropyrimidines. With the recognition that topoisomerase-I (TOP-I) is an important therapeutic target in cancer therapy, irinotecan, a semisynthetic TOP-I-interactive camptothecin derivative, has been clinically established in the treatment of colorectal cancer. RESULTS Irinotecan was investigated as second-line chemotherapy after prior treatment with fluorouracil (FU)-based regimens in two large randomized phase III trials comparing irinotecan with either best supportive care or an infusional FU/leucovorin (LV) regimen. The outcomes of these trials established irinotecan as the standard therapy in the second-line treatment of colorectal cancer. The therapeutic value of irinotecan in the first-line treatment of metastatic colorectal cancer was investigated in two large randomized phase III trials comparing the combination of irinotecan and FU/LV with FU/LV alone. Both trials demonstrated significant superior efficacy for the combination of irinotecan and FU/LV in terms of response rate, median time to disease progression, and median survival time. Consequently, the combination of irinotecan and FU/LV has been approved as first-line chemotherapy for patients with metastatic colorectal cancer and constitutes the reference therapy against which other treatment options must be tested in the future. CONCLUSION In this review, the clinical rationale and update of the present clinical status of irinotecan in the treatment of colorectal cancer and future prospects of irinotecan-based combinations are discussed.

Phase II study with the combination etoposide, doxorubicin, and cisplatin in advanced measurable gastric cancer.

In this phase II multicenter trial, 67 evaluable patients with advanced measurable gastric carcinoma were treated with a combination of etoposide, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and cisplatin (EAP). The overall response rate was 64%, including 21% complete responses (CRs). In 55 patients with metastatic disease, 31 responses (51%) including eight CRs (15%) were achieved. Responses were seen in all metastatic sites, but the response rate was lower in patients with peritoneal carcinomatosis. In 12 patients with locoregional disease, six CRs and six partial responses (PRs) were observed. Eight CRs (three and five in patients with metastatic and locoregional disease, respectively) were pathologically confirmed. The overall median response duration was 7 months; it was 16 months for patients achieving CR (22 months for pathologically confirmed CR [pCR]), and 6 months for PR. The median survival time for all patients was 9 months, for the patients who achieved CR 17 months, for pCR 23 months, and for PR 9.5 months. Median survival time for all patients with metastatic disease was 8 months, and for locoregional disease 12.5 months. Six patients (9%) (four local, two metastatic disease) were alive at 2 years, and four patients are alive and disease free at 35+ to 56+ months. Main toxicities were leukopenia and thrombocytopenia, with 64% of patients developing grade 3 to 4 myelosuppression and 12% severe infections. Nonhematologic toxicities of World Health Organization (WHO) grade 4 were not observed.

Preoperative chemotherapy in locally advanced and nonresectable gastric cancer: a phase II study with etoposide, doxorubicin, and cisplatin.

Thirty-four patients with locally advanced, nonresectable gastric cancer (staged by laparotomy) received etoposide, Adriamycin (doxorubicin; Adria Laboratories, Columbus, OH), and cisplatin (EAP). Thirty-three patients were evaluable for response and toxicity. Second-look surgery with removal of residual tumor by gastrectomy and lymphadenectomy was performed in case of complete/partial remission (CR/PR) after EAP. After successful resection (R0- and R1-resection), two cycles of EAP were administered for consolidation therapy. Patients refusing reoperation received up to six cycles of EAP. The response rate (CR/PR) after EAP was 70% (23/33), including a 21% (7/33) rate of clinical CRs (CCRs). Two patients had minor remission (MR)/no change and seven had progressive disease. There was one early death. Nineteen of 23 responders (5 CCRs, 14 clinical PRs [CPRs]) and one patient with MR underwent second-look surgery. Five CCRs were pathologically confirmed; 10 patients with CPR were without evidence of disease (NED) after resection. In three patients (CPR), R1-resections (microscopically tumor-cell positive proximal margin) were performed; two patients are disease-free, 22+ and 33+ months after consolidation chemotherapy. In two patients, the tumor was again considered nonresectable. Twenty patients were disease-free after EAP +/- surgery +/- consolidation chemotherapy. Toxicity was primarily hematologic. Leukopenia and thrombocytopenia of World Health Organization (WHO) grade 3 occurred in 30% and 9%, respectively and grade 4 in 18% and 9% of the patients, respectively. There was no increased peri- or postoperative morbidity. After a median follow-up of 20 months for disease-free patients, the relapse rate is 60% (12/20). The median survival time for all patients is 18 months and for disease-free patients 24 months. EAP is highly effective in locally advanced gastric cancer, and offers a chance for surgery with curative intention in patients with an otherwise fatal prognosis.

New developments in the treatment of gastric carcinoma

The recent successes being achieved with combination chemotherapy regimens strongly indicate that gastric cancer is chemosensitive. With these regimens, objective remission rates of more than 50% were recorded, including approximately 10% complete remission (CRs). The finding that locally advanced disease (LAD) and technically unresectable disease could be rendered resectable by preoperative chemotherapy (EAP) was important. The median survival time was 18 months for all patients and 24 months for disease-free patients. At 30+ months, 21% of all patients are still living disease free. The expected survival of patients with unresectable LAD is approximately 4-6 months without any treatment and 6-9 months with standard chemotherapy. Compared with the latter results, the preoperative use of etoposide, adriamycin, and platinum (EAP) seems to improve the prognosis of patients with LAD. Moreover, such a multimodal approach may increase the number of long-term survivors among patients with resectable gastric cancer, especially those whose stage indicates a high risk of relapse (stage IIIa or IIIb). However, partly because of the severe toxicities (myelo-suppression, nausea/vomiting), a considerable number of patients cannot be treated with these new regimens. Considering the predominantly palliative treatment intentions in far-advanced (metastasized) gastric cancer, regimens with low toxicities and acceptable activity should be preferred. For these reasons, we developed and investigated the combination etoposide, leucovorin, and 5-FU (ELF) in a phase II trial in elderly patients (greater than 65 years) and in patients with cardiac risks who could not be treated with anthracyclines. The overall response rate in 51 evaluable patients was 53%, including six clinical CRs (12%). The median remission duration was 9.5 months and the median survival time was 11 months. Tolerability was excellent. The high remission rate and long medical survival time achieved with ELF, plus its good tolerability, make this combination a valuable alternative to anthracycline-containing regimens. In addition to developing new treatment plans and strategies, it is also desirable to predict treatment outcome with an acceptable degree of certainty. Combinations of variable defined patient subgroups with significantly different probabilities for achieving objective response and for survival. The results of this analysis may contribute to a more patient-oriented and risk-adapted chemotherapy and to better comparability of future studies.

Phase I Study of a Weekly Schedule of Irinotecan, High-Dose Leucovorin, and Infusional Fluorouracil as First-Line Chemotherapy in Patients With Advanced Colorectal Cancer

PURPOSE To determine the maximum-tolerated dose (MTD) of a weekly schedule of irinotecan (CPT-11), leucovorin (LV), and a 24-hour infusion of fluorouracil (5-FU24h) as first-line chemotherapy in advanced colorectal cancer and to assess preliminary data on the antitumor activity. PATIENTS AND METHODS Twenty-six patients with measurable metastatic colorectal cancer were entered onto this phase I study. In the first six dose levels, fixed doses of CPT-11 (80 mg/m2) and LV (500 mg/m2) in combination with escalated doses of 5-FU24h ranging from 1.8 to 2.6 g/m2 were administered on a weekly-times-four (dose levels 1 to 4) or weekly-times-six (dose levels 5 to 6) schedule. The dose of CPT-11 was then increased to 100 mg/m2 (dose level 7). RESULTS Seventy-nine cycles of 5-FU24h/LV with CPT-11 were administered in an outpatient setting. No dose-limiting toxicities were observed during the first cycle at dose levels 1 to 6, but diarrhea of grade 4 (National Cancer Institute common toxicity criteria) was observed in three patients after multiple treatment cycles. Other nonhematologic and hematologic side effects, specifically alopecia and neutropenia, did not exceed grade 2. With the escalation of CPT-11 to 100 mg/m2 (dose level 7), diarrhea of grade 3 or higher was observed in four of six patients during the first cycle; thus, the MTD was achieved. Sixteen of 25 response-assessable patients (64%; 95% confidence interval, 45% to 83%) achieved an objective response. CONCLUSION The recommended doses for further studies are CPT-11 80 mg/m2, LV 500 mg/m2, and 5-FU24h 2.6 g/m2 given on a weekly-times-six schedule followed by a 1-week rest period. The addition of CPT-11 to 5-FU24h/LV seems to improve the therapeutic efficacy in terms of tumor response with manageable toxicity.

New systemic frontline treatment for metastatic colorectal carcinoma

Options for first‐line chemotherapy in patients with metastatic colorectal carcinoma have broadened considerably with the introduction of irinotecan and oxaliplatin. Furthermore, the oral fluoropyrimidine capecitabine has demonstrated efficacy in Phase III trials and recently was approved for first‐line treatment in Europe and the United States. Capecitabine yielded similar median times to disease progression and median survival rates compared with bolus 5‐fluorouracil (5‐FU)/leucovorin (LV) (Mayo Clinic/North Central Cancer Treatment Group regimen), with superior and similar response rates, respectively. However, its role as a first‐line, single‐agent substitute for intermittent infusional 5‐FU/LV remains to be defined. The addition of irinotecan or oxaliplatin to 5‐FU/LV resulted in improved response rates and progression‐free survival in large, randomized trials; moreover, irinotecan‐containing regimens resulted in improved overall survival. Prevalent regimens of irinotecan/5‐FU/LV and oxaliplatin/5‐FU/LV have been compared in two randomized Phase III trials. One study demonstrated the statistical superiority of oxaliplatin/infusional 5‐FU/LV over irinotecan/bolus 5‐FU/LV in terms of response, time to disease progression, and median survival; however, those advantages may have been attributable to infusional administration or to major differences in second‐line therapy. A randomized Phase III study comparing irinotecan and oxaliplatin in combination with the same infusional 5‐FU/LV regimens and crossover in case of disease progression showed equivalent efficacy for both schedules in the first‐line setting, but the irinotecan combination proved beneficial in terms of safety. New molecular targeted agents, such as angiogenesis‐modulating compounds (e.g., bevacizumab) and epidermal growth factor receptor inhibitors (e.g., cetuximab), are under clinical investigation. This review updates current systemic frontline treatments and future perspectives for patients with advanced colorectal carcinoma. Cancer 2004.

Etoposide, folinic acid, and 5-fluorouracil in carboplatin-pretreated patients with advanced gastric cancer

SummaryA group of 20 patients with gastric cancer, refractory to or with no change after two or three cycles of carboplatin were treated with etoposide/folinic acid/5-fluorouracil (ELF). An objective remission rate of 45% (9/20), a median remission duration of 8 months and a median survival time of 11 months were achieved. Toxicities were mild to moderate only. These results are comparable to those being achieved with ELF in previously untreated gastric cancer patients and confirm its efficacy and good tolerability.

5-Fluorouracil, folinic acid, etoposide and cisplatin chemotherapy for locally advanced or metastatic carcinoma of the oesophagus

38 patients with advanced oesophageal carcinoma were treated with intravenous (i.v.) folinic acid (300 mg/m2), 5-fluorouracil (500 mg/m2), etoposide (100 mg/m2), and cisplatin (30 mg/m2) (FLEP), on days 1, 2 and 3, every 22-28 days. 26 patients had locally advanced disease (LAD) and 12 had metastatic disease (M1). Oesophagectomy was planned for patients with LAD in case of tumour regression after chemotherapy, while patients with M1 disease received chemotherapy only. The overall remission rate was 45% (17/38) including four clinical and two pathologically confirmed complete remissions. 16 patients underwent oesophagectomy, 12 after response to FLEP, and 4 after FLEP and subsequent irradiation +/- 5-fluorouracil/mitomycin. Toxicity was mainly haematological, with WHO grade 3 and 4 leukocytopenia in 50% and thrombocytopenia in 31% of the patients. Two treatment-related deaths were observed; one due to chemotherapy and one postoperatively. Median survival time of LAD patients was 13 months, and actuarial 2-year survival was 31%. Patients with complete tumour resection after FLEP had a median survival time of 18 months and a 2-year survival rate of 42%. Median survival of M1 patients was 6 months. FLEP is an active combination for oesophageal cancer, especially when used preoperatively in LAD.

Phase II study of carboplatin/ifosfamide in untreated advanced cervical cancer

SummaryA total of 32 patients with advanced squamous-cell carcinoma of the cervix were treated with 300 mg/m2 i. v. carboplatin and 5 g/m2 ifosfamide as a 24-h i. v. infusion, both given on day 1 every 4 weeks. In all, 3 (9%) complete responses (CRs) and 19 (59%) objective responses (CR+PR) were achieved in 32 patients. Myelosuppression with leukopenia and/or thrombocytopenia of WHO grade 4 in 28% and 13% of patients, respectively, was the main toxicity. The results of our study suggest that carboplatin/ifosfamide is active as neoadjuvant treatment in advanced cervical cancer.

Etoposide and split-dose cisplatin in small-cell lung cancer.

Forty-seven untreated patients with small-cell lung cancer (SCLC) were treated with a combination of etoposide ( 170 mg/m2 intravenously, i.v., days 3–5) and cisplatin (50 mg/ m2 i.v., days 1 and 7). Responding patients with limited disease received four cycles followed by irradiation (delivered to the primary site, mediastinum, and supraclavicular region) with 50 Gy. Prophylactic cranial irradiation (PCI) with 30 Gy was performed in patients who achieved complete remission. Responding patients with extensive disease received four to six cycles of chemotherapy. The overall objective response rate (complete response plus partial response, CR + PR) was 94% (44 of 47). CR rate (all patients) was 57% (27 of 47), 51% (19 of 37) in extensive disease and 80% (8 of 10) in limited disease. The median remission duration is 13 months (12 months in extensive disease and 26 months in limited disease). The median survival is 16 months for all patients ( 15 months in extensive disease, 28 months in limited disease). Mean follow-up is 13 months. Toxicity was primarily hematologie. Twelve of 47 patients had leukopenia of WHO grade 4, 30 of 47 of grade 3. Thrombocytopenia of WHO grade 3 and 4 occurred in 6 of 47 and 2 of 47 patients, respectively. There were four severe infections in neutropenic patients, but no chemotherapy-related lethal complications. The only treatment-related death was that of one patient who died in CR of progressive neurologic dysfunction 11 months after PCI. This schedule of etoposide and cisplatin induces high CR rates and a prolonged survival, especially in patients with extensive disease.