Phase II trial of cetuximab in patients with refractory colorectal cancer that expresses the epidermal growth factor receptor

PURPOSE

To evaluate the antitumor activity and toxicity of single-agent cetuximab in patients with chemotherapy-refractory colorectal cancer whose tumors express the epidermal growth factor receptor.

PATIENTS AND METHODS

Phase II, open-label clinical trial. Patients were required to have EGFr expression demonstrated on formalin-fixed paraffin-embedded tumor tissue by immunohistochemical staining before study participation. Patients were required to have received irinotecan, either alone or in a combination regimen, and to have demonstrated clinical failure on this regimen before study entry. Cetuximab was administered weekly by intravenous infusion. The first dose of 400 mg/m(2) was given during the course of 2 hours. Subsequent weekly treatments were given at a dose of 250 mg/m(2) during the course of 1 hour.

RESULTS

Fifty-seven eligible patients were treated. All were assessable for toxicity and response. The most commonly encountered grade 3 to 4 adverse events, regardless of relationship to study drug, were an acne-like skin rash, predominantly on the face and upper torso (86% with any grade; 18% with grade 3), and a composite of asthenia, fatigue, malaise, or lethargy (56% with any grade, 9% with grade 3). Two patients (3.5%) experienced grade 3 allergic reactions requiring discontinuation of study treatment. A third patient experienced a grade 3 allergic reaction that resolved, and the patient continued on the study. Neither diarrhea nor neutropenia were dose limiting in any of the 57 patients treated. Five patients (9%; 95% CI, 3% to 19%) achieved a partial response. Twenty-one additional patients had stable disease or minor responses. The median survival in these previously treated patients with chemotherapy-refractory colorectal cancer is 6.4 months.

CONCLUSION

Cetuximab on this once-weekly schedule has modest activity and is well-tolerated as a single agent in patients with chemotherapy-refractory colorectal cancer whose tumors express the epidermal growth factor receptor. Further studies of cetuximab will evaluate the use of cetuximab in conjunction with first-line and adjuvant treatments for this disease.

A Phase II Study of Intravenous Exatecan Mesylate (DX-8951f) Administered Daily for Five Days Every Three Weeks to Patients with Metastatic Adenocarcinoma of the Colon or Rectum

BACKGROUND

To evaluate the antitumor activity, toxicities, and pharmacokinetics (PK) of DX-8951f administered as a 30-min infusion daily for 5 days every 3 weeks in patients with fluorouracil-resistant metastatic colorectal carcinoma.

PATIENTS AND METHODS

Sixteen patients were enrolled. All had metastatic colorectal carcinoma resistant to or progressing after chemotherapy containing 5-fluorouracil and no prior chemotherapy with camptothecin derivatives. DX-8951f was administered until disease progression or unacceptable toxicity. Responses were assessed after every two courses.

RESULTS

Fifteen patients were evaluable. Fifty-one courses of therapy were delivered (median 2). Responses were one minor response, six stable disease, and eight progressive disease. The principal adverse event was neutropenia, with grade 3 and 4 toxicities in three and eight patients, respectively. Non-hematologic toxicities were mild to moderate; the most common were fatigue, nausea, and diarrhea. Plasma concentrations of DX-8951 were well described using a linear two-compartment PK model. There was no evidence of nonlinearity in the elimination of PK or auto-inhibition or induction of DX-8951 clearance over the 5 days of administration.

CONCLUSIONS

DX-8951f at this dose and schedule had no significant activity in this patient population. The toxicity profile, mainly hematologic, was consistent with previous reports. The clearance and volume of distribution were not different from those previously reported.

Irinotecan (Campto) in the treatment of pancreatic cancer

Irinotecan (Campto) is a topoisomerase I inhibitor currently approved for the treatment of metastatic colon cancer. Single-agent irinotecan has also demonstrated modest activity in a number of other advanced solid tumors, including lung, gastric and pancreatic cancer. Preclinical data suggest a potentially additive and/or synergistic interaction between irinotecan and gemcitabine (Gemzar). This combination has demonstrated improved response rates in patients with pancreatic cancer. Unfortunately, a recently reported Phase III trial of gemcitabine with or without irinotecan revealed no survival benefit for the combination. Future combinations of irinotecan continue to be explored in an effort to further improve the treatment of this relatively chemorefractory disease. Thus far, no single agent or combination has been shown to be superior to gemcitabine alone as palliative therapy for advanced/metastatic pancreatic cancer. A promising combination of irinotecan with oxaliplatin (Eloxatin) and fluorouracil will be assessed in a Phase III study.

Understanding and managing chemotherapy-induced diarrhea

Diarrhea is particularly problematic in patients receiving fluoropyrimidines and/or irinotecan. Careful patient monitoring, patient education, and good patient-provider communication are the primary tools of prevention. The patient must be carefully evaluated on a regular basis early in treatment, so that mid-course corrections, dose adjustments, or dose delays can be instituted early on if indicated. Diet need not be modified as a preventive measure, but once diarrhea occurs, a number of modifications must be made. Maintenance of fluid intake is critical and inability to maintain adequate hydration would be a primary indication for parenteral fluid support. Oral intake of fluids should not be limited to plain water only, since electrolytes need to be replenished. Early recognition of diarrhea and early pharmacologic intervention can greatly facilitate successful resolution of this treatment complication.

Clinical characteristics and outcomes from an institutional series of acinar cell carcinoma of the pancreas and related tumors

PURPOSE

Acinar cell carcinoma is a rare tumor of the exocrine pancreas. Clinical features such as prognostic information, survival, and treatment outcomes are unknown. We present the largest retrospective review to date.

PATIENTS AND METHODS

Thirty-nine patients with pathologically confirmed acinar neoplasms of the pancreas were identified between August 1981 and January 2001. Demographic data, tumor characteristics, and treatment information were obtained by chart review. Survival probabilities were estimated by using the Kaplan-Meier method and compared using the log-rank test.

RESULTS

The median survival for all patients was 19 months. On the basis of a univariate analysis, the patients' stage of disease correlated significantly with survival. The median survival of patients with localized disease was 38 months, versus 14 months for those presenting with metastases (P = 0.03). Patients who could be treated with surgery as first-line therapy had a longer survival time (36 months) compared with those who did not have surgery (14 months). Two of 18 patients who received chemotherapy and three of eight patients who received radiation had a major response.

CONCLUSION

The survival curves suggest a more aggressive cancer than pancreatic endocrine neoplasms but one that is less aggressive than ductal adenocarcinoma of the pancreas. Those patients who present with localized disease have a much better prognosis than those who present with metastases. There is a high recurrence rate after complete surgical resection, suggesting that micrometastases are present even in localized disease and that adjuvant therapies may be indicated. Chemotherapy and radiation afford disappointing results, however, and novel therapies are needed.

Radical resection of rectal cancer primary tumor provides effective local therapy in patients with stage IV disease

BACKGROUND

The optimal use of radical surgery to palliate primary rectal cancers presenting with synchronous distant metastases is poorly defined. We have reviewed stage IV rectal cancer patients to evaluate the effectiveness of radical surgery without radiation as local therapy.

METHODS

Eighty stage IV patients with resectable primary rectal tumors treated with radical rectal surgery without radiotherapy were identified. Sixty-one (76%) patients received chemotherapy; response information was available for 34 patients.

RESULTS

Radical resection was accomplished by low anterior resection (n = 65), abdominoperineal resection (n = 11), and Hartmann's resection (n = 4). Surgical complications were seen in 12 patients (15%), with 1 death and 4 reoperations. The local recurrence rate was 6% (n = 5), with a median time to local recurrence of 14 months. Only one patient received pelvic radiotherapy as salvage treatment. One patient required subsequent diverting colostomy. Median survival was 25 months. On multivariate analysis, the extent of metastasis and response to chemotherapy were determinants of prolonged survival.

CONCLUSIONS

For patients who present with distant metastases and resectable primary rectal cancers, radical surgery without radiotherapy can provide durable local control with acceptable morbidity. The extent of metastatic disease and the response to chemotherapy are the major determinants of survival. Effective systemic chemotherapy should be given high priority in the treatment of stage IV rectal cancer.

Adjuvant therapy of cancers of the colon and rectum

Important advances have been made in our understanding of the role of adjuvant therapy for colorectal cancer. Current standard 5FU-based regimens have been convincingly shown to reduce the incidence of recurrences and to prolong overall survival in patients with resected stage III colon cancer. Colon cancer patients with stage II disease have a better-overall prognosis than those with stage III; however, the relative merits of adjuvant treatment in these patients remains controversial. Combined chemotherapy plus radiation therapy is currently the standard adjuvant approach for stage II and III rectal cancer patients. Despite the advances that have been made, far too many patients with resectable colorectal cancer ultimately relapse and die of their disease. There remains a pressing need for continued development of improved adjuvant treatments. Participation of eligible patients in clinical trials must continue to be actively encouraged. Only in this way will we be able to continue to build and expand on the progress that has been made thus far.

A phase II trial of farnesyl protein transferase inhibitor SCH 66336, given by twice-daily oral administration, in patients with metastatic colorectal cancer refractory to 5-fluorouracil and irinotecan

BACKGROUND

ras genes encode Ras proteins that are important for signal transduction in cancer cells. Farnesyl protein transferase (FPTase) is an enzyme that is responsible for a critical post-translational modification of Ras.

PATIENTS AND METHODS

We report the results of a phase II trial of SCH 66336, an FPTase inhibitor, in patients with metastatic colorectal cancer. This is the first reported experience of an FPTase inhibitor in this disease. All patients were considered refractory to first- and second-line therapy. A total of 21 evaluable patients were treated with a starting dose of 200 mg b.i.d. given continuously.

RESULTS

The major side-effects were fatigue (grade 1 in 42%, grade 2 in 42% and grade 3 in 14%), diarrhea (grade 1 in 23% and grade 3 in 42%) and nausea (grade 2 in 16%). Elevations in serum creatinine (grade 2 or 3) were observed in 19% of patients and appeared to be related to dehydration induced by diarrhea. Significant hematological toxicity was not observed (only grade 1 thrombocytopenia in 19% and grade 2 or 3 anemia in 28%). Pharmacological studies revealed adequate mean pre-dose plasma concentrations in this group of patients on day 15 of therapy. No objective responses were observed, although stable disease was seen in three patients for several months. Administration of SCH 66336 was accompanied by gastrointestinal toxicity.

CONCLUSIONS

Future development of this compound cannot be recommended as monotherapy in this disease.

Safe and cost effective use of alteplase for the clearance of occluded central venous access devices

PURPOSE

To determine whether cryopreserved solutions of the thrombolytic agent alteplase could be used as a safe, effective, and economically reasonable alternative to urokinase in patients presenting with occluded central venous access devices (CVADs).

MATERIALS AND METHODS

Alteplase has been reported as an efficacious alternative to urokinase for treatment of occluded CVADs. However, the practicality of using alteplase as the thrombolytic of choice for this indication remained conjectural. To make this approach economically feasible, alteplase was diluted to 1 mg/mL and 2.5-mL aliquots were stored at -20 degrees C until use. A need to confirm that the cryopreserving and thawing of the reconstituted solution did not compromise the safety and efficacy reported from prior trials was recognized. A quality assessment initiative was undertaken to concurrently monitor the safety and efficacy of this approach. Patients presenting with occluded CVADs received a sufficient volume of the thawed alteplase solution to fill the occluded catheter(s). Data, including efficacy, adverse reactions, dwell time, and catheter type, were collected over a 5-month period.

RESULTS

One hundred twenty-one patients accounting for 168 attempted clearances were assessable for safety and efficacy. One hundred thirty-six (81%) of the 168 catheter clearance attempts resulted in successful catheter clearance (95% confidence interval, 74% to 86%). No adverse events were reported.

CONCLUSION

Cryopreserved 1-mg/mL aliquots of alteplase are safe and effective in the clearance of occluded CVADs when stored at -20 degrees C for 30 days. The ability to cryopreserve alteplase aliquots makes it an economically reasonable alternative to urokinase in the setting of CVAD occlusion.

Assessing the predictive value of clinical complete response to neoadjuvant therapy for rectal cancer: an analysis of 488 patients

BACKGROUND

Patients with transmural or node-positive rectal cancer benefit from the addition of chemoradiation to surgical resection. Administration of the chemoradiation (combined modality therapy) preoperatively has gained popularity in recent years. Some patients undergo apparent complete tumor regression after preoperative combined modality therapy, and controversy exists about the proper management of these patients. Some investigators have proposed that such patients should simply be observed and not undergo resection.

STUDY DESIGN

The purpose of this study was to determine the significance of clinical complete response to preoperative combined modality therapy. Specifically, we have attempted to determine the frequency with which a clinical complete response (based on the absence of detectable tumor on preoperative digital rectal examination and proctoscopy) correlates with a pathologic complete response (based on the absence of cancer cells in the resected specimen). A retrospective review of the clinical and pathologic characteristics of 488 patients from the Memorial Sloan-Kettering prospective colorectal database who received preoperative chemoradiation followed by resection for primary rectal cancer was performed. The indications for preoperative therapy included clinical or ultrasound T3 or T4 tumors or node-positive disease.

RESULTS

The clinical complete response rate to preoperative therapy was 19%. All patients underwent resection subsequent to preoperative therapy regardless of response. The pathologic complete response rate among all patients was 10%. The pathologic complete response rate among clinical complete responders was 25%. Clinical complete response was a significant predictive factor for pathologic complete response, but the majority (75%) of clinical complete responders had persistent foci of tumor that were not detectable on preoperative examination or proctoscopy.

CONCLUSIONS

Clinical complete response to preoperative therapy as determined by preoperative digital rectal examination and proctoscopy or EUA is not an accurate predictor of pathologic complete response. A significant percentage of clinical complete responders have persistent deep tumors or nodal involvement. We do not recommend making treatment decisions based solely on the absence of clinically palpable or visible tumor after chemoradiation. Our data suggest that all acceptable-risk patients with a diagnosis of primary rectal cancer should undergo resection, regardless of their response to preoperative therapy.

A phase II study of irinotecan in patients with advanced hepatocellular carcinoma

BACKGROUND

Advanced hepatocellular carcinoma has a poor prognosis. In a Phase II clinical trial, two academic centers assessed irinotecan, a topoisomerase-1 inhibitor with broad spectrum clinical activity, in patients who had advanced hepatocellular cancer.

METHODS

Patients who had had up to one prior chemotherapy regimen were eligible. Bidimensionally measurable disease, a good performance status, and adequate major organ function were required. At a starting dose of 125 mg/m2, irinotecan was administered weekly for 4 weeks followed by a 2 week break, which constituted 1 treatment cycle. Patients were restaged radiologically after two cycles of therapy. Dose attenuations were made as indicated for toxicity.

RESULTS

Fourteen patients were enrolled over a 10-week period in 1997. There were ten males and four females. The median age was 58 years (range, 38-74 yrs). The Eastern Cooperative Oncology Group median performance status was 1 (range, 0-1). Two patients had prior chemotherapy (14%), and 1 patient (7%) had had radiation. A total of 30 cycles of therapy were delivered (median, 1; range, 1-6). Considerable toxicity was observed, mostly neutropenia, diarrhea, nausea, vomiting, and fatigue. All patients required at least one dose attenuation for toxicity. One partial response (7%; confidence interval, 0-20%) was noted to last 7 months. One patient had transient stable disease, and all others (86%) had progression of disease as their best response.

CONCLUSIONS

Irinotecan had modest activity in advanced hepatocellular cancer. Toxicity was substantial, presumably reflecting impaired underlying liver function or poor ability to metabolize and eliminate the drug. The current study indicated that continued new therapy assessment is warranted for this disease.

A phase II study of irinotecan in patients with advanced hepatocellular carcinoma

BACKGROUND

Advanced hepatocellular carcinoma has a poor prognosis. In a Phase II clinical trial, two academic centers assessed irinotecan, a topoisomerase-1 inhibitor with broad spectrum clinical activity, in patients who had advanced hepatocellular cancer.

METHODS

Patients who had had up to one prior chemotherapy regimen were eligible. Bidimensionally measurable disease, a good performance status, and adequate major organ function were required. At a starting dose of 125 mg/m2, irinotecan was administered weekly for 4 weeks followed by a 2 week break, which constituted 1 treatment cycle. Patients were restaged radiologically after two cycles of therapy. Dose attenuations were made as indicated for toxicity.

RESULTS

Fourteen patients were enrolled over a 10-week period in 1997. There were ten males and four females. The median age was 58 years (range, 38-74 yrs). The Eastern Cooperative Oncology Group median performance status was 1 (range, 0-1). Two patients had prior chemotherapy (14%), and 1 patient (7%) had had radiation. A total of 30 cycles of therapy were delivered (median, 1; range, 1-6). Considerable toxicity was observed, mostly neutropenia, diarrhea, nausea, vomiting, and fatigue. All patients required at least one dose attenuation for toxicity. One partial response (7%; confidence interval, 0-20%) was noted to last 7 months. One patient had transient stable disease, and all others (86%) had progression of disease as their best response.

CONCLUSIONS

Irinotecan had modest activity in advanced hepatocellular cancer. Toxicity was substantial, presumably reflecting impaired underlying liver function or poor ability to metabolize and eliminate the drug. The current study indicated that continued new therapy assessment is warranted for this disease.

A phase II study of irinotecan in patients with advanced hepatocellular carcinoma

BACKGROUND

Advanced hepatocellular carcinoma has a poor prognosis. In a Phase II clinical trial, two academic centers assessed irinotecan, a topoisomerase-1 inhibitor with broad spectrum clinical activity, in patients who had advanced hepatocellular cancer.

METHODS

Patients who had had up to one prior chemotherapy regimen were eligible. Bidimensionally measurable disease, a good performance status, and adequate major organ function were required. At a starting dose of 125 mg/m2, irinotecan was administered weekly for 4 weeks followed by a 2 week break, which constituted 1 treatment cycle. Patients were restaged radiologically after two cycles of therapy. Dose attenuations were made as indicated for toxicity.

RESULTS

Fourteen patients were enrolled over a 10-week period in 1997. There were ten males and four females. The median age was 58 years (range, 38-74 yrs). The Eastern Cooperative Oncology Group median performance status was 1 (range, 0-1). Two patients had prior chemotherapy (14%), and 1 patient (7%) had had radiation. A total of 30 cycles of therapy were delivered (median, 1; range, 1-6). Considerable toxicity was observed, mostly neutropenia, diarrhea, nausea, vomiting, and fatigue. All patients required at least one dose attenuation for toxicity. One partial response (7%; confidence interval, 0-20%) was noted to last 7 months. One patient had transient stable disease, and all others (86%) had progression of disease as their best response.

CONCLUSIONS

Irinotecan had modest activity in advanced hepatocellular cancer. Toxicity was substantial, presumably reflecting impaired underlying liver function or poor ability to metabolize and eliminate the drug. The current study indicated that continued new therapy assessment is warranted for this disease.

Phase I study of topoisomerase I inhibitor exatecan mesylate (DX-8951f) given as weekly 24-hour infusions three of every four weeks

Exatecan mesylate (DX-8951f) is a topoisomerase I inhibitor that has increased solubility and antitumor activity compared with other topoisomerase I inhibitors. The purpose of this study was to establish a safe dose of DX-8951f given as a weekly 24-h infusion 3 of every 4 weeks. DX-8951f was administered as a 24-h continuous infusion in escalating doses. Twenty-seven patients were treated with 81 courses of the drug. Dose-limiting toxicities included neutropenia, thrombocytopenia, and inability to administer all three doses in the first cycle. In minimally pretreated patients, a dose of 0.8 mg/m(2) was tolerable. In patients who were heavily pretreated, a slightly lower dose, 0.53 mg/m(2), was tolerated without any severe toxicities. Nonhematological toxicities were mild and consisted of mild diarrhea, asthenia, mild nausea, and constipation. Pharmacokinetic parameters could be well described with a one-compartment model in most patients, although the application of the one-compartment model probably resulted in an underestimated elimination half-life. In conclusion, the recommended Phase II dose for DX-8951f administered as a weekly 24-h infusion on a 3-of-4 week schedule is 0.8 mg/m(2) in minimally pretreated patients and 0.53 mg/m(2) in patients who are heavily pretreated.

Surgical debulking and intraperitoneal chemotherapy for established peritoneal metastases from colon and appendix cancer

BACKGROUND

Aggressive treatment of peritoneal metastases from colon cancer by surgical cytoreduction and infusional intraperitoneal (IP) chemotherapy may benefit selected patients. We reviewed our institutional experience to assess patient selection, complications, and outcome.

METHODS

Patients having surgical debulking and IP 5-fluoro-2'-deoxyuridine (FUDR) plus leucovorin (LV) for peritoneal metastases from 1987 to 1999 were evaluated retrospectively.

RESULTS

There were 64 patients with a mean age of 50 years. Primary tumor sites were 47 in the colon and 17 in the appendix. Peritoneal metastases were synchronous in 48 patients and metachronous in 16 patients. Patients received IP FUDR (1000 mg/m2 daily for 3 days) and IP leucovorin (240 mg/m2) with a median cycle number of 4 (range, 1-28). The median number of complications was 1 (range, 0-5), with no treatment related mortality. Only six patients (9%) required termination of IP chemotherapy because of complications. The median follow-up was 17 months (range, 0-132 months). The median survival was 34 months (range, 2-132); 5-year survival was 28%. Lymph node status, tumor grade, and interval to peritoneal metastasis were not statistically significant prognostic factors for survival. Complete tumor resection was significant on multivariate analysis (P = .04), with a 5-year survival of 54% for complete (n = 19) and 16% for incomplete (n = 45) resection.

CONCLUSIONS

Surgical debulking and IP FUDR for peritoneal metastases from colon cancer can be accomplished safely and has yielded an overall 5-year survival of 28%. Complete resection is associated with improved survival (54% at 5 years) and is the most important prognostic indicator.

The role of irinotecan in colorectal cancer

Irinotecan, also known as CPT-11, is a topoisomerase I inhibitor currently approved for use as a second-line agent in the treatment of advanced colorectal cancer. Preliminary reports from randomized studies exploring combinations of CPT-11 plus 5-fluorouracil have shown improved antitumor activity versus 5-fluorouracil-based treatments alone, and suggest a first-line role for these combination regimens. The role of CPT-11/5-fluorouracil regimens in the adjuvant setting is now being actively explored. Studies of single-agent CPT-11 in the first-line treatment of metastatic colorectal cancer have shown activity; however response rates do not appear to be superior to those seen with standard first-line 5-fluorouracil-based regimens. The use of specific molecular markers as prognostic indicators of response or resistance to specific chemotherapies may, however, permit the identification of a selected population of patients with tumor characteristics that would specifically favor consideration of up-front use of single-agent CPT-11.

New therapies, new directions: advances in the systemic treatment of metastatic colorectal cancer

Colorectal cancer is the second leading cause of cancer death and it is clear that patients with metastatic disease have better quality of life and survival when given treatment. Despite four decades of experience of treating patients with fluorouracil, there remains considerable controversy about the optimum dose and scheduling, as well as biomodulation with leucovorin and methotrexate. However, irrespective of the dose and schedule, overall survival times are poor--about 1 year. Disappointingly, oral agents with similar mechanisms to fluorouracil do not improve survival rates in comparison with fluorouracil and leucovorin treatment. Irinotecan and oxaliplatin are newer agents that have improved the response rates for patients with metastatic disease when they are added to flurouracil and leucovorin. The combination of irinotecan, fluorouracil, and leucovorin has also improved overall survival. These are small advances in the fight against colorectal cancer, and further drug development is necessary.

Irinotecan plus fluorouracil/leucovorin for metastatic colorectal cancer: a new survival standard

BACKGROUND

Irinotecan is a topoisomerase I inhibitor that prolongs survival in patients with colorectal cancer refractory to fluorouracil (5-FU) and leucovorin (LV). This demonstrated activity of irinotecan as effective second-line therapy for colorectal cancer led to evaluation of combination irinotecan/5-FU/LV as first-line therapy for patients with metastatic disease. The results of two prospective phase III randomized, controlled, multicenter, multinational clinical trials in patients with previously untreated metastatic colorectal cancer served as the basis for U.S. and European approval of irinotecan/5-FU/LV for this indication. An overview of the findings of these two pivotal studies provides insights regarding the application of this new combination in clinical practice.

METHODS

Patients were randomly assigned to receive 5-FU/LV, either alone, or with concurrent irinotecan. The study conducted primarily in North America (study 1), employed bolus 5-FU/LV schedules, while the study performed primarily in Europe (study 2), employed infusional 5-FU/LV regimens. Major endpoints included tumor response rate, time to tumor progression (TTP), overall survival, quality of life, and safety.

RESULTS

In study 1, the respective confirmed response rates for irinotecan/5-FU/LV versus 5-FU/LV were 39% and 21% (p <.001); median TTPs were 7.0 months and 4.3 months, respectively (p =.004). In study 2, response rates for irinotecan/5-FU/LV versus 5-FU/LV alone were 35% and 22% (p =.005); median TTPs were 6.7 months and 4.4 months, respectively (p <.001). Survival time increased significantly with irinotecan/5-FU/LV versus 5-FU/LV alone in both studies (study 1: median 14.8 months versus 12.6 months, p =.042; study 2: median 17.4 months versus 14.1 months, p =.032). The combined analysis of the data from the two studies showed median survivals of 15.9 months versus 13.3 months, favoring the irinotecan-containing combinations (stratified-by-study p =.003). Patients in study 1 had a 36% lower risk of tumor progression and a 20% lower risk of death with the irinotecan combination than with 5-FU/LV alone; comparable risk reduction values in study 2 were 42% and 23%. While grade 3 diarrhea and vomiting were more common with irinotecan/5-FU/LV, grade 4 neutropenia, neutropenic fever, and mucositis were less common with irinotecan/5-FU/LV than with the Mayo Clinic 5-FU/LV regimen.

CONCLUSION

The combination of irinotecan/5-FU/LV is superior to 5-FU/LV alone as first-line therapy for patients with metastatic colorectal cancer, offering consistently improved tumor control and prolonged survival. Irinotecan-based combination therapy sets a new survival standard for the treatment of this life-threatening disease.

A phase II trial of irinotecan (CPT-11) for unresectable biliary tree carcinoma

BACKGROUND

Unresectable adenocarcinomas of the biliary tree have a very poor prognosis. No good chemotherapeutic regimen is available. Irinotecan has not yet been fully tested in this disease. We evaluated its activity in unresectable bile duct cancers.

PATIENTS AND METHODS

Twenty-five consecutive eligible patients at our two institutions were treated with irinotecan at a starting dose of 125 mg/m2. A cycle consisted of once-a-week treatments for four consecutive weeks, followed by two weeks of rest. All patients were required to have histologically confirmed diagnosis, clinically documented metastatic or unresectable carcinoma and measurable disease. Patients were evaluated for response, toxicity, and survival.

RESULTS

A total of 83 cycles of therapy were delivered. Two patients had a partial response (8%; 95% confidence interval (CI): 0%-18%) and ten additional patients had stable disease for at least two months (40%; 95% CI: 20.8%-59.2%). The therapy was well tolerated, with moderate myelosuppression and diarrhea as the main toxicities. The overall median survival was 10 months.

CONCLUSIONS

Irinotecan has minimal activity in biliary tree carcinomas, but is well tolerated with appropriate supportive care, and produces occasional objective responses.

A phase II study of irinotecan in patients with advanced hepatocellular carcinoma

BACKGROUND

Advanced hepatocellular carcinoma has a poor prognosis. In a Phase II clinical trial, two academic centers assessed irinotecan, a topoisomerase-1 inhibitor with broad spectrum clinical activity, in patients who had advanced hepatocellular cancer.

METHODS

Patients who had had up to one prior chemotherapy regimen were eligible. Bidimensionally measurable disease, a good performance status, and adequate major organ function were required. At a starting dose of 125 mg/m2, irinotecan was administered weekly for 4 weeks followed by a 2 week break, which constituted 1 treatment cycle. Patients were restaged radiologically after two cycles of therapy. Dose attenuations were made as indicated for toxicity.

RESULTS

Fourteen patients were enrolled over a 10-week period in 1997. There were ten males and four females. The median age was 58 years (range, 38-74 yrs). The Eastern Cooperative Oncology Group median performance status was 1 (range, 0-1). Two patients had prior chemotherapy (14%), and 1 patient (7%) had had radiation. A total of 30 cycles of therapy were delivered (median, 1; range, 1-6). Considerable toxicity was observed, mostly neutropenia, diarrhea, nausea, vomiting, and fatigue. All patients required at least one dose attenuation for toxicity. One partial response (7%; confidence interval, 0-20%) was noted to last 7 months. One patient had transient stable disease, and all others (86%) had progression of disease as their best response.

CONCLUSIONS

Irinotecan had modest activity in advanced hepatocellular cancer. Toxicity was substantial, presumably reflecting impaired underlying liver function or poor ability to metabolize and eliminate the drug. The current study indicated that continued new therapy assessment is warranted for this disease.

Irinotecan plus fluorouracil and leucovorin for metastatic colorectal cancer. Irinotecan Study Group

BACKGROUND

The combination of fluorouracil and leucovorin has until recently been standard therapy for metastatic colorectal cancer. Irinotecan prolongs survival in patients with colorectal cancer that is refractory to treatment with fluorouracil and leucovorin. In a multicenter trial, we compared a combination of irinotecan, fluorouracil and leucovorin with bolus doses of fluorouracil and leucovorin as first-line therapy for metastatic colorectal cancer. A third group of patients received irinotecan alone.

METHODS

Patients were randomly assigned to receive irinotecan (125 mg per square meter of body-surface area intravenously), fluorouracil (500 mg per square meter as an intravenous bolus), and leucovorin (20 mg per square meter as an intravenous bolus) weekly for four weeks every six weeks; fluorouracil (425 mg per square meter as an intravenous bolus) and leucovorin (20 mg per square meter as an intravenous bolus) daily for five consecutive days every four weeks; or irinotecan alone (125 mg per square meter intravenously) weekly for four weeks every six weeks. End points included progression-free survival and overall survival.

RESULTS

Of 683 patients, 231 were assigned to receive irinotecan, fluorouracil, and leucovorin; 226 to receive fluorouracil and leucovorin; and 226 to receive irinotecan alone. In an intention-to-treat analysis, as compared with treatment with fluorouracil and leucovorin, treatment with irinotecan, fluorouracil, and leucovorin resulted in significantly longer progression-free survival (median, 7.0 vs. 4.3 months; P=0.004), a higher rate of confirmed response (39 percent vs. 21 percent, P<0.001), and longer overall survival (median, 14.8 vs. 12.6 months; P=0.04). Results for irinotecan alone were similar to those for fluorouracil and leucovorin. Grade 3 (severe) diarrhea was more common during treatment with irinotecan, fluorouracil, and leucovorin than during treatment with fluorouracil and leucovorin, but the incidence of grade 4 (life-threatening) diarrhea was similar in the two groups (<8 percent). Grade 3 or 4 mucositis, grade 4 neutropenia, and neutropenic fever were less frequent during treatment with irinotecan, fluorouracil, and leucovorin. Adding irinotecan to the regimen of fluorouracil and leucovorin did not compromise the quality of life.

CONCLUSIONS

Weekly treatment with irinotecan plus fluorouracil and leucovorin is superior to a widely used regimen of fluorouracil and leucovorin for metastatic colorectal cancer in terms of progression-free survival and overall survival.

High-dose-rate intraoperative brachytherapy for recurrent colorectal cancer

PURPOSE

Management of locally recurrent colorectal adenocarcinoma represents a significant challenge. Many of these tumors adhere to or invade into vital pelvic structures rendering surgery or external beam radiotherapy (EBRT) as palliative treatment. Therefore, a treatment approach was developed to evaluate the role of high-dose-rate intraoperative brachytherapy (HDR-IORT) and surgery as a component of therapy in the management of locally recurrent colorectal cancer. This is an update of our preliminary report with longer follow-up and larger patient numbers.

METHODS AND MATERIALS

Between January 1992 and September 1998, 74 patients with locally recurrent rectal cancer were treated with surgery and HDR-IORT. Additional EBRT was given to 29 patients, and 33 patients received 5-fluorouracil based chemotherapy. All patients underwent complete gross resection, and 21 of 74 had positive microscopic margin. The dose of HDR-IORT ranged from 10 to 18 Gy.

RESULTS

With a median follow-up of 22 months, the 5-year local control, distant metastasis disease-free, disease-free, and overall survival rates were 39%, 39%, 23%, and 23%, respectively. The only predictor of improved local control was a negative margin of resection with a 5-year local control rate of 43%, compared to 26% in those with positive margin (p = 0.02). For overall survival, a negative microscopic margin (p = 0.04) and the use of IORT + EBRT (p = 0.04) were significant predictors of improved survival. The incidence of peripheral neuropathy was 16%.

CONCLUSION

The results with HDR-IORT in this group of patients are encouraging. Further improvements in local and distant control are still needed.

Oral chemotherapeutic agents for colorectal cancer

A number of novel oral chemotherapeutic agents are entering practice or are under development in the United States. Many of these agents display significant clinical activity against colorectal cancer. Many classes of compounds, including fluoropyrimidine analogs, dihydropyrimidine dehydrogenase (DPD) inhibitors, topoisomerase inhibitors, farnesyl transferase inhibitors, and others, are being developed for oral administration. This manuscript describes the progress of clinical development of these agents and also explores the relative merits and challenges of these approaches. Economic issues, patient preference, and patient selection issues surrounding oral chemotherapy for colorectal cancer will also be discussed.

MethyLight: a high-throughput assay to measure DNA methylation

Cytosine-5 DNA methylation occurs in the context of CpG dinucleotides in vertebrates. Aberrant methylation of CpG islands in human tumors has been shown to cause transcriptional silencing of tumor-suppressor genes. Most methods used to analyze cytosine-5 methylation patterns require cumbersome manual techniques that employ gel electrophoresis, restriction enzyme digestion, radiolabeled dNTPs or hybridization probes. The development of high-throughput technology for the analysis of DNA methylation would significantly expand our ability to derive molecular information from clinical specimens. This study describes a high-throughput quantitative methylation assay that utilizes fluorescence-based real-time PCR (TaqMan) technology that requires no further manipulations after the PCR step. MethyLight is a highly sensitive assay, capable of detecting methylated alleles in the presence of a 10,000-fold excess of unmethylated alleles. The assay is also highly quantitative and can very accurately determine the relative prevalence of a particular pattern of DNA methylation. We show that MethyLight can distinguish between mono-allelic and bi-allelic methylation of the MLH1 mismatch repair gene in human colorectal tumor specimens. The development of this technique should considerably enhance our ability to rapidly and accurately generate epigenetic profiles of tumor samples.

Failure to confirm major objective antitumor activity for streptozocin and doxorubicin in the treatment of patients with advanced islet cell carcinoma

BACKGROUND

The combination regimen of streptozocin plus doxorubicin is the current standard chemotherapeutic treatment of symptomatic or progressing metastatic islet cell carcinoma. This regimen previously has been reported to have a major objective response rate of 69% in a randomized cooperative group trial. However, the authors believed that this favorable response rate was not consistent with their institutional experience at Memorial Sloan-Kettering Cancer Center (MSKCC).

METHODS

The authors retrospectively reviewed the records of all islet cell carcinoma patients under care at MSKCC who were treated with streptozocin plus doxorubicin since the publication of the study mentioned earlier. Sixteen such patients treated between February 1992 and February 1998 were identified. Their clinical characteristics, sites of measurable disease, response to treatment, time to treatment failure, and survival status were reviewed.

RESULTS

All patients were treated with the starting doses as outlined by the published cooperative group report. All had bidimensionally measurable disease on computed tomography (CT) scans. Only 1 of 16 patients (6%; 95% confidence interval, 0-30%) achieved a major objective response by standard CT response criteria, with response ongoing during treatment at 18 months. Nine patients (56%) had stable disease while receiving treatment (range of treatment, 2-17+ months). Six patients (38%) had progression of disease as their best response while receiving treatment. The median overall survival of this patient group had not yet been reached at last follow-up, with > 60% of patients alive with follow-up ranging from 10-67+ months.

CONCLUSIONS

A retrospective analysis of the authors' 6-year experience with the combination of streptozocin plus doxorubicin in patients with islet cell carcinoma failed to confirm the high objective response rate previously reported for this regimen. There remains an urgent need for improved chemotherapeutic alternatives for patients with this disease.

CpG island hypermethylation in human colorectal tumors is not associated with DNA methyltransferase overexpression

The molecular basis of aberrant hypermethylation of CpG islands observed in a subset of human colorectal tumors is unknown. One potential mechanism is the up-regulation of DNA (cytosine-5)-methyltransferases. Recently, two new mammalian DNA methyltransferase genes have been identified, which are referred to as DNMT3A and DNMT3B. The encoded proteins differ from the predominant mammalian DNA methyltransferase DNMT1 in that they have a substantially higher ratio of de novo to maintenance methyltransferase activity. We have used a highly quantitative 5' nuclease fluorogenic reverse transcription-PCR method (TaqMan) to analyze the expression of all three DNA methyltransferase genes in 25 individual colorectal adenocarcinoma specimens and matched normal mucosa samples. In addition, we examined the methylation patterns of four CpG islands [APC, ESR1 (estrogen receptor), CDKN2A (p16), and MLH1] to determine whether individual tumors show a positive correlation between the level of DNA methyltransferase expression and the frequency of CpG island hypermethylation. All three methyltransferases appear to be up-regulated in tumors when RNA levels are normalized using either ACTB (beta-actin) or POLR2A (RNA pol II large subunit), but not when RNA levels are normalized with proliferation-associated genes, such as H4F2 (histone H4) or PCNA. The frequency or extent of CpG island hypermethylation in individual tumors did not correlate with the expression of any of the three DNA methyltransferases. Our results suggest that deregulation of DNA methyltransferase gene expression does not play a role in establishing tumor-specific abnormal DNA methylation patterns in human colorectal cancer.

Phase II clinical trial of 13-cis-retinoic acid and interferon-alpha-2a in patients with advanced esophageal carcinoma

BACKGROUND

Interferon in combination with 5-fluorouracil has been shown to be active in squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the esophagus. 13-cis-retinoic acid (CRA) has chemopreventive activity in SCC of the head and neck, and, in combination with interferon, has antitumor activity in SCC of the skin and cervix.

METHODS

The activity and toxicity of CRA and interferon-alpha-2a (IFN) in patients with advanced esophageal carcinoma was evaluated in a Phase II single institution trial. Patients had unresectable or metastatic AC or SCC of the esophagus. One prior chemotherapy regimen was allowed. IFN was given by daily subcutaneous injection at a dose of 3 million U and CRA was taken orally at a dose of 1 mg/kg/day in 2 divided doses. Treatment was given in cycles of 4 weeks and continued until documented disease progression.

RESULTS

Of the 19 patients entered, 15 were evaluable for response and toxicity. One patient was evaluable for response only and one patient was evaluable for toxicity only. Evaluable patients were predominantly male (15 patients), and had AC (13 patients). All had AJCC Stage IV disease and 12 were pretreated. Patients completed an average of two cycles of therapy (range, one to six cycles) prior to progression of disease. National Cancer Institute Common Toxicity Criteria Grade 3/4 toxicity was notable for nausea (25%) and fatigue (31%). No major objective responses were recorded. Eleven patients with AC and 3 patients with SCC had rapid progression of disease. One patient with AC was found to have a minor response for 22 weeks and 1 patient with AC had stable disease for 45 weeks.

CONCLUSIONS

This regimen had no significant activity in patients with advanced AC of the esophagus. Further evaluation of IFN plus CRA, using this dose and schedule, is not recommended. In comparison with prior trials of this therapy, a surprising amount of severe nausea and fatigue was observed in this trial.

A phase II trial of interferon alpha-2a and carboplatin in patients with advanced malignant mesothelioma

We defined the antitumor activity, toxicity, and tolerability of a combined chemoimmunotherapy approach in patients with advanced malignant mesothelioma using daily low-dose interferon alpha-2a and carboplatin given every 4 weeks. This was a phase II study of 15 patients with surgically unresectable or metastatic malignant mesothelioma. All patients had measurable or assessable disease. No prior chemotherapy or immunotherapy was allowable. Carboplatin was given at 150 mg/m2 daily on days 1-3 and interferon alpha-2a at 3 million units subcutaneously daily throughout the study. Treatment was recycled every 28 days. Therapy was continued until disease progression. Fifteen patients were assessable for toxicity and 14 for response. One partial response (7%, 95% CI, 0-20%), with a response duration of 40 weeks, was seen. Most patients had early progression of disease. Toxicity was tolerable, and grade III/IV toxicity was uncommon. The median time to progression was 14 weeks (range, 1-52 weeks). The median survival was 25 weeks (range, 8-66 weeks). The combination of low-dose interferon alpha-2a and carboplatin did not result in greater antitumor activity than that reported for single-agent carboplatin in advanced malignant mesothelioma. Although toxicity was mild, carboplatin and low-dose interferon, given at this dose and schedule, cannot be recommended for this patient group.

Phase II clinical trial of 13-cis-retinoic acid and interferon-alpha-2a in patients with advanced esophageal carcinoma

BACKGROUND

Interferon in combination with 5-fluorouracil has been shown to be active in squamous cell carcinoma (SCC) and adenocarcinoma (AC) of the esophagus. 13-cis-retinoic acid (CRA) has chemopreventive activity in SCC of the head and neck, and, in combination with interferon, has antitumor activity in SCC of the skin and cervix.

METHODS

The activity and toxicity of CRA and interferon-alpha-2a (IFN) in patients with advanced esophageal carcinoma was evaluated in a Phase II single institution trial. Patients had unresectable or metastatic AC or SCC of the esophagus. One prior chemotherapy regimen was allowed. IFN was given by daily subcutaneous injection at a dose of 3 million U and CRA was taken orally at a dose of 1 mg/kg/day in 2 divided doses. Treatment was given in cycles of 4 weeks and continued until documented disease progression.

RESULTS

Of the 19 patients entered, 15 were evaluable for response and toxicity. One patient was evaluable for response only and one patient was evaluable for toxicity only. Evaluable patients were predominantly male (15 patients), and had AC (13 patients). All had AJCC Stage IV disease and 12 were pretreated. Patients completed an average of two cycles of therapy (range, one to six cycles) prior to progression of disease. National Cancer Institute Common Toxicity Criteria Grade 3/4 toxicity was notable for nausea (25%) and fatigue (31%). No major objective responses were recorded. Eleven patients with AC and 3 patients with SCC had rapid progression of disease. One patient with AC was found to have a minor response for 22 weeks and 1 patient with AC had stable disease for 45 weeks.

CONCLUSIONS

This regimen had no significant activity in patients with advanced AC of the esophagus. Further evaluation of IFN plus CRA, using this dose and schedule, is not recommended. In comparison with prior trials of this therapy, a surprising amount of severe nausea and fatigue was observed in this trial.

Phase I clinical and pharmacologic study of weekly cisplatin combined with weekly irinotecan in patients with advanced solid tumors

PURPOSE

In vitro synergy between cisplatin and irinotecan (CPT-11) has been reported. We designed a combination schedule of these agents to maximize the potential for synergistic interaction.

PATIENTS AND METHODS

To maximize the opportunity for synergy, we divided the cisplatin into four consecutive weekly treatments, followed by a 2-week rest. Each dose of cisplatin was immediately followed by a dose of irinotecan. The dose of cisplatin was fixed at 30 mg/m2/wk. The initial irinotecan dose was 50 mg/m2/wk and this was escalated by 30% increments in successive cohorts of three to six patients to establish the maximum-tolerated dose (MTD). Pharmacokinetics of irinotecan and its metabolites, SN-38 and SN-38 glucuronide (SN-38G), were analyzed.

RESULTS

Of 35 patients with solid tumors enrolled onto this trial, 30 were assessable for toxicity and response. The MTD for this regimen was 30 mg/m2/wk of cisplatin plus 50 mg/m2/wk of irinotecan in previously treated patients and 30 mg/m2/wk of cisplatin plus 65 mg/m2/wk of irinotecan in chemotherapy-naive patients. Neutropenia was the dose-limiting toxicity (DLT) encountered in this trial. Diarrhea was infrequent and rarely dose-limiting. Seven of 30 assessable patients achieved a partial response. No alteration in irinotecan, SN-38, or SN-38G pharmacokinetics resulted from the administration of cisplatin with irinotecan.

CONCLUSION

The administration of cisplatin and irinotecan on this weekly schedule provides a practical and well-tolerated regimen that has the potential to maximize any clinical synergy between the two agents. Evidence of substantial clinical activity was seen in this phase I study.

Irinotecan and cisplatin in upper gastrointestinal malignancies

Irinotecan (CPT-11 [Camptosar]), an active agent in the treatment of fluorouacil-refractory colorectal cancer, has antitumor activity in upper gastrointestinal cancers. Clinical trials from Japan indicate antitumor responses in gastric and pancreatic cancers. Cisplatin (Platinol), a central agent in the treatment of upper gastrointestinal malignancies, is a logical drug to study in combination with irinotecan in upper gastrointestinal cancers. In vitro studies have shown important sequence-dependent synergy of cisplatin/irinotecan combination therapy. Irinotecan appears to prevent removal of cisplatin-induced DNA-interstrand cross-links. Initial phase I and III trials of cisplatin plus irinotecan appear to confirm this synergy, with Japanese trials in gastric cancer showing an encouraging rate of response with acceptable toxicity. A phase I trial conducted at Memorial Sloan-Kettering Cancer Center has demonstrated the safety and tolerability of weekly cisplatin and irinotecan. Currently, a phase II trial of this weekly regimen is under way in patients with metastatic or recurrent esophageal cancer. The response proportion compares favorably to standard therapy, with relatively mild toxicity. Other phase II studies, including single-agent irinotecan in esophageal cancer and the combination of cisplatin and irinotecan in gastric cancer, are being initiated at other US institutions.

Irinotecan in the first-line treatment of colorectal cancer

Irinotecan (CPT-11 [Camptosar]) is currently approved for use as a second-line agent in the treatment of metastatic colorectal cancer. Phase II studies have also shown substantial single-agent activity of irinotecan in the first-line treatment of metastatic colorectal cancer. Response rates appear to be similar to those seen with standard first-line regimens, although direct randomized comparisons have not yet been reported. In the absence of definitive data showing irinotecan to be superior, its routine use as a single agent in the first-line treatment of colorectal cancer may be hard to justify, given the significant cost differential between irinotecan and current standard first-line regimens. Studies exploring combinations of irinotecan with fluorouracil may identify a first-line role for these combination regimens. Also, use of specific molecular markers may permit the identification of selected patients with tumor characteristics that would specifically favor consideration of upfront irinotecan monotherapy.

A phase II study of topotecan administered five times daily in patients with advanced gastric cancer

OBJECTIVE

Topotecan (Tpt), a semisynthetic analogue of camptothecin (Cpt), has shown excellent preclinical activity in a number of solid tumors. Cpt, the parent compound, has preclinical activity against several gastrointestinal tumors, including a gastric adenocarcinoma xenograft. A phase-II clinical trial was conducted to assess the activity to Tpt in patients with advanced gastric cancer.

MATERIALS AND METHODS

15 patients with advanced, incurable gastric adenocarcinomas were treated. Tpt 1.5 (mg/m2/day) was administered intravenously as a 30-min infusion daily for 5 consecutive days. Treatments were repeated on a 21-days cycle.

RESULTS

No major objective responses were observed in 13 evaluable patients (response rate = 0%; 95% confidence interval = 0-22%). The major dose-limiting toxicity in this trial was myelosuppression, which was severe in this patient population.

CONCLUSIONS

Tpt at the dose and schedule studies does not possess substantial antitumor activity in patient with gastric cancer, and the toxicities were formidable. We do not advocate further development of this drug in the treatment of gastric cancer. Tpt has shown more promising activity and tolerability in other patient populations, and these areas deserve further exploration.

9-Aminocamptothecin by 72-hour continuous intravenous infusion is inactive in the treatment of patients with 5-fluorouracil-refractory colorectal carcinoma

BACKGROUND

9-Aminocamptothecin (9AC) and its parent compound, camptothecin, have shown outstanding preclinical activity against colorectal carcinoma. Irinotecan (CPT-11), another camptothecin derivative, has demonstrated clinical activity in patients with 5-fluorouracil (5-FU)-refractory colorectal carcinoma.

METHODS

The authors performed a Phase II trial of 9AC involving patients with measurable metastatic colorectal carcinoma who had progressed through only one prior regimen of 5-FU-based chemotherapy. 9AC was given initially at a dose of 59 microg/m2/hour by continuous intravenous infusion for 72 hours, with treatments repeated every 14 days. Granulocyte-colony stimulating factor was given on Days 5-12.

RESULTS

Sixteen patients were treated on this trial. Fourteen were evaluable for response. Contrary to expectations, no major objective antitumor responses were observed. Eight patients experienced stable disease for a median of 4.1 months (range, 2.2-9.5 months). Toxicities, especially myelosuppression, were severe and necessitated a 15% reduction in the initial dose after the first 9 patients. Toxicities at this reduced dose remained unacceptable.

CONCLUSIONS

9AC did not demonstrate substantial activity against 5-FU-refractory colorectal carcinoma on the schedule studied. Toxicities at the doses and schedule studied were unacceptable in this patient population. Based on their results, the authors consider it unlikely that 9AC administered as a 72-hour continuous intravenous infusion will play a major role in the treatment of colorectal carcinoma.

Adjuvant treatment of colorectal cancer

The adjuvant therapy of colorectal cancer has seen many important advances in recent years. Chemotherapy improves long-term disease-free survival rates in high-risk patients with resected colon cancer. Combined modality therapy, using surgery, radiation therapy, and chemotherapy, improves both local control and survival in patients with stage II and III rectal cancer. We examine in detail the data on which current recommendations for adjuvant treatments are based. We also review some of the more promising experimental approaches currently under investigation.

Phase I clinical and pharmacokinetic study of irinotecan, fluorouracil, and leucovorin in patients with advanced solid tumors

PURPOSE

To determine the maximum-tolerable dose (MTD) of fluorouracil (5FU) when given with fixed doses of leucovorin and irinotecan (CPT-11), to define the dose-limiting toxicities of this combination, and to evaluate the effect of 5FU on the pharmacokinetics of CPT-11.

PATIENTS AND METHODS

CPT-11, leucovorin, and 5FU were administered in repeated 6-week cycles that consisted of weekly treatment with all three drugs for 4 consecutive weeks followed by a 2-week break. On day 1 of treatment, CPT-11 alone was given by 90-minute infusion, and pharmacokinetic sampling was performed over 24 hours. Leucovorin and 5FU were administered by brief intravenous injection on day 2. On days 8, 15, and 22, CPT-11 infusion was immediately followed by leucovorin and then 5FU. A second 24-hour pharmacokinetic sampling was performed on day 8, which permitted comparison of the pharmacokinetics of CPT-11 with and without 5FU. For the second 6-week cycle, leucovorin was administered first, followed by 5FU and then CPT-11, and a third pharmacokinetic sampling was performed.

RESULTS

Forty-two patients were entered onto this trial. The CPT-11 dose was initially fixed at 100 mg/m2. Leucovorin was fixed at 20 mg/m2. 5FU doses of 210, 265, 340, 425, and 500 mg/m2 were studied. When the 500-mg/m2 dose of 5FU was found to be tolerable, this was then maintained and CPT-11 was escalated to 125 and then 150 mg/m2. This final CPT-11 dose exceeded the MTD. Neutropenia was the major dose-limiting toxicity. Diarrhea was common, but was rarely dose-limiting. Coadministration of 5FU had no substantial effect on the pharmacokinetics of CPT-11 or SN-38. Among the 38 patients with colorectal cancer, six partial responses (PRs) were seen in this predominantly 5FU-refractory patient population.

CONCLUSION

5FU does not substantially affect the metabolism of CPT-11 to its active metabolite, SN-38. The combination of CPT-11125 mg/m2, 5FU 500 mg/m2, and leucovorin 20 mg/m2 is feasible and tolerable on this schedule.

Influence of inflammatory bowel disease on the ability of patients to tolerate systemic fluorouracil-based chemotherapy

PURPOSE

To evaluate the safety of administering fluorouracil (5FU)-based chemotherapy to cancer patients with inflammatory bowel disease (IBD).

PATIENTS AND METHODS

We retrospectively reviewed all patients entered into the Memorial Sloan-Kettering Cancer Center clinical data base from 1985 through 1995 who had a diagnosis of IBD, had a gastrointestinal malignancy, and were treated with systemic 5FU-based chemotherapy. A total of 19 patient charts were identified and reviewed.

RESULTS

Fifty-three percent of patients reviewed experienced severe (grade III/IV) diarrhea on treatment. Sixty percent of patients with a history of active IBD and 40% of patients with a history of inactive IBD experienced severe diarrhea on treatment. The incidence of severe diarrhea did not appear to be substantially influenced by age, schedule of 5FU administration, concurrent radiation, or type of IBD.

CONCLUSION

While there does appear to be an increased risk of diarrhea exacerbation in IBD patients treated with 5FU, a substantial number of patients tolerate chemotherapy without increased difficulty. The degree of IBD activity or other clinical parameters can not be used to predict accurately the likelihood of toxicity.

Irinotecan is an active agent in untreated patients with metastatic colorectal cancer

PURPOSE

To determine the response rate, survival, and toxicity of the new anticancer agent, irinotecan (CPT-11), in the treatment of metastatic colorectal cancer.

PATIENTS AND METHODS

Forty-one chemotherapy-naive patients with measurable metastatic colorectal cancer were treated with a 90-minute infusion of irinotecan 125 mg/m2 administered weekly for 4 weeks every 6 weeks. Pretreatment tumor biopsies to assess topoisomerase-I (Topo-I) activity were obtained from 11 patients. The pharmacokinetics for irinotecan and its active metabolite, SN-38, were determined in 18 patients.

RESULTS

Thirteen of 41 patients (32%) had a partial response (PR; 95% confidence interval, 18% to 46%). The median response duration was 8.1 months (range, 4.0 to 16.0) and the median survival time was 12.1 months (range, 2.1 to 21.7) for all 41 patients. Grade 3 or 4 toxicities were diarrhea (29% of patients) and neutropenia (22% of patients). Grade 3 or 4 diarrhea was substantially more prevalent in the initial 18 patients on study, with an incidence rate of 56%; a significant reduction in the incidence of severe diarrhea to 9% was noted with strict adherence to an antidiarrheal regimen of loperamide and diphenyldramine. No correlations were seen between pharmacokinetics of irinotecan/SN-38 and the clinical parameters of response, survival, or incidence of diarrhea.

CONCLUSIONS

Irinotecan has activity in the treatment of patients with metastatic colorectal cancer. Strict adherence to an antidiarrheal regimen of diphenhydramine/loperamide significantly reduced the incidence of diarrhea; the agent was thereafter well tolerated in the majority of patients.

A fixed-ratio combination of uracil and Ftorafur (UFT) with low dose leucovorin. An active oral regimen for advanced colorectal cancer

BACKGROUND

UFT is a fixed-ratio combination of uracil and Ftorafur, a prodrug that is absorbed orally and metabolized in vivo to 5-fluorouracil (5-FU). Uracil potentiates 5-FU through interference with its catabolism. The combination of UFT and leucovorin in patients with advanced incurable colorectal cancer, to evaluate preliminary activity and toxicity in this patient population.

METHODS

Twenty-one patients were treated. Twenty patients were evaluable for toxicity and response. Patients received UFT 350 mg/m2/day divided every 8 hours. Patients took a 5 mg tablet of leucovorin every 8 hours, concurrent with each UFT dose. Treatment was continued for 28 consecutive days, followed by a 7-day rest.

RESULTS

Five major objective responses (one complete and four partial) were observed. Toxicity was mild, with no dose-limiting myelosuppression. Four patients experienced grade 3 diarrhea or higher, and two patients experienced dose-limiting mucositis.

CONCLUSION

UFT and low dose leucovorin is a well tolerated, orally administered regimen with activity in colorectal cancer. A randomized comparison of this regimen with conventional parenteral regimens is warranted.

Continuous infusion fluorouracil/leucovorin and bolus mitomycin-C as a salvage regimen for patients with advanced colorectal cancer

BACKGROUND

No effective systemic salvage therapy exists for patients with advanced colorectal cancer who progress after receiving bolus fluorouracil (FU) and leucovorin (LV) chemotherapy. In vitro data suggest that bolus FU resistance can be overcome by continuous infusion (CI) FU, and that the cytotoxic effects of Mitomycin-C (MMC) and FU are synergistic. Based on this data, a Phase II trial of CI FU and LV with bolus MMC in patients with advanced colorectal carcinoma who progressed on only one previous chemotherapy regimen was performed.

METHODS

Twenty-eight patients with advanced colorectal carcinoma who had progressed after one previous chemotherapy regimen of bolus FU/LV were treated with bolus MMC 10 mg/m2 every 6 weeks and CI FU 200 mg/m2/day admixed with LV 10 mg/m2/day given 14 days on/7 days off.

RESULTS

The partial response rate in 24 evaluable patients was 17% (95% confidence interval, 2-32%) with a median response duration of 9.5 months (range, 4.2-12.0 months). Twelve (50%) additional patients achieved disease stabilization. Median survival was 9.9 months in the whole group (28 patients) and 11.5 months in the 24 evaluable patients. The major toxicities were grade 4 diarrhea occurring in two patients and grade 3 mucositis occurring in five patients. There was minimal myelosuppression (grade 3 thrombocytopenia in one patient) and no occurrences of hand-foot syndrome or cardiotoxicity.

CONCLUSIONS

This regimen demonstrates modest activity with acceptable toxicity in colorectal cancer patients who have failed a single-bolus FU/LV regimen. Modifications of this and other infusional FU-based chemotherapy regimens should be explored as potential salvage chemotherapy regimens in advanced colorectal cancer.