Measuring response in solid tumors: unidimensional versus bidimensional measurement.

BACKGROUND: Tumor shrinkage is a common end point used in screening new cytotoxic agents. The standard World Health Organization criterion for partial response is a 50% or more decrease in the sum of the products of two measurements (the maximum diameter of a tumor and the largest diameter perpendicular to this maximum diameter) of individual tumors. However, theoretically, the simple sum of the maximum diameters of individual tumors is more linearly related to cell kill than is the sum of the bidimensional products. It has been hypothesized that the calculation of bidimensional products is unnecessary, and a 30% decrease in the sum of maximum diameters of individual tumors (assuming spherical shape and equivalence to a 50% reduction in the sum of the bidimensional products) was proposed as a new criterion. We have applied the standard response and the new response criteria to the same data to determine whether the same number of responses in the same patients would result. METHODS: Data from 569 patients included in eight studies of a variety of cancers were reanalyzed. The two response criteria were separately applied, and the results were compared using the kappa statistic. The importance of confirmatory measurements and the frequency of nonspherical tumors were also examined. In addition, for a subset of 128 patients, a unidimensional criterion for disease progression (30% increase in the sum of maximum diameters) was applied and compared with the standard definition of a 25% increase in the sum of the bidimensional products. RESULTS: Agreement between the unidimensional and bidimensional criteria was generally found to be good. The kappa statistic for concordance for overall response was 0.95. CONCLUSION: We conclude that one dimensional measurement of tumor maximum diameter may be sufficient to assess change in solid tumors.

Docetaxel in patients with metastatic breast cancer: a phase II study of the National Cancer Institute of Canada-Clinical Trials Group.

PURPOSE: The National Cancer Institute of Canada-Clinical Trials Group (NCIC-CTG) conducted a phase II study to assess the efficacy and toxicity of docetaxel as first-line chemotherapy in metastatic breast cancer (MBC). PATIENTS AND METHODS: Fifty-one patients with measurable MBC were studied. Three patients were ineligible and were excluded from analysis. The planned dose of docetaxel was 100 mg/m2 intravenously (i.v.) every 3 weeks. Prior adjuvant chemotherapy was allowed if at least 12 months had elapsed from completion of treatment to recurrence. RESULTS: The most severe toxicity was granulocytopenia. Ten patients (20.8%) were hospitalized for febrile neutropenia. The protocol was amended to a starting dose of 75 mg/m2 for the last 16 patients. Sixty percent of patients experienced hypersensitivity reactions (HSRs). After two protocol amendments, the use of a premedication regimen of oral dexamethasone and i.v. H1 and H2 blockers prevented significant HSRs. Edema developed in 62% of patients and was cumulative, was present in 50% who received greater than 400 mg/m2, and was not improved by premedication regimens. Following an independent radiology review, 22 partial remissions and four complete responses in 47 assessable patients were confirmed (response rate, 55%; 95% confidence interval [CI], 40% to 69%). The response rate for 15 assessable patients registered at 75 mg/m2 was 40% (95% CI, 16% to 67%); for 32 assessable patients registered at 100 mg/m2, the response rate was 63%, (95% CI, 43% to 78%). CONCLUSION: Docetaxel is an active agent in MBC. Its activity as a single agent is comparable to many combination chemotherapy regimens and is not affected by prior adjuvant chemotherapy. Studies are ongoing to improve its therapeutic index and to incorporate docetaxel in combination chemotherapy regimens.

Phase II study of subcutaneous rHu-interleukin-2 and rHu-interferon alpha-2a in previously treated patients with multiple myeloma.

BACKGROUND: Several studies have shown that interferon alpha as a single agent produces responses in multiple myeloma patients, and may produces responses in multiple myeloma of interleukin-2 (rHu-IL-2) in multiple myeloma models indicate that rHu-IL-2 may have a therapeutic effect. In this phase II clinical trial, we combined rHu-interferon alpha-2a (rHu-IFN-2a) and rHu-IL-2, to assess the feasibility, toxicity and response rate when this treatment was given as subcutaneous injections to previously treated patients with relapsed or refractory multiple myeloma. PATIENTS AND METHODS: Seventeen patients with measurable serum M protein or urine paraprotein were entered on the study. Three patients were refractory to first line treatment; fourteen had relapsed following response to prior treatment. rHu-IFN alpha-2a was given three times per week continuously. rHu-IL-2 was given three times per week for 6 weeks followed by a 2-week break from treatment. Patients were assessed for response and toxicity at 4-week intervals. RESULTS: All patients were eligible and evaluable for toxicity; two patients were invaluable for response because they did not complete 4 weeks of treatment. All response-evaluable patients had a best objective response of stable disease which lasted a median of 22 weeks and was maintained for over one year in 5 patients. Toxicity was tolerable and was typical of rHu-IL-2 and rHu-IFN alpha-2a; fever, chills or rigors and lethargy were nearly universal; local toxicity at the injection site, headache, anorexia, nausea and vomiting were also common. CONCLUSIONS: No objective responses in serum M protein or urine paraprotein levels were noted thus we do not recommend further study of this combination in myeloma.

Didemnin B in favourable histology non-Hodgkin's lymphoma. A phase II study of the National Cancer Institute of Canada Clinical Trials Group.

Ten patients with previously untreated stage III/IV low grade histology non-Hodgkin's lymphoma received a 1-hour intravenous infusion of Didemnin B 2.3 mg/m2 weekly for 4 weeks repeated every 6 weeks. 40% of patients experienced significant hypersensitivity reactions, one of which was life-threatening, despite premedication with diphenhydramine and cimetidine. Other toxicities included nausea, vomiting, fatigue, diarrhea and skin rashes. No objective responses were seen. Given the serious toxicity and lack of activity in a non-pretreated group of patients, the study was closed early. Further investigation of Didemnin B at this dose and schedule is not recommended.

Gemcitabine is an active new agent in previously untreated extensive small cell lung cancer (SCLC). A study of the National Cancer Institute of Canada Clinical Trials Group.

BACKGROUND: The new pyrimidine antimetabolite Gemcitabine has shown preclinical efficacy in a number of solid tumour lines and acceptable toxicity in phase I trials. As part of an ongoing effort to identify active new agents in small cell lung cancer, the NCIC Clinical Trials Group studied Gemcitabine in previously untreated patients with extensive disease. PATIENTS AND METHODS: Twenty-nine newly diagnosed patients with untreated extensive small cell lung cancer and at least one bidimensionally measurable site received Gemcitabine as a 30 minute intravenous infusion weekly x 3 every 4 weeks. The starting dose was 1000 mg/m2/week in the first 17 patients and 1250 mg/m2/week in the remainder. Patients were reevaluated for response every 4 weeks. Those failing to respond after 2 cycles of therapy were to be offered standard chemotherapy. RESULTS: Of the 29 patients entered, all were evaluable for toxicity and 26 for response. One complete and 6 partial responses were seen giving a response rate of 27% (95% CI: 11%-47%). Median response duration was 12.5 weeks and the median survival of the entire population was 12 months. Toxic effects were mild to moderate: in particular serious myelosuppression was uncommon. CONCLUSIONS: Gemcitabine is active in previously untreated small cell lung cancer in doses which produce little toxicity. Combination studies of Gemcitabine with other agents active in this disease are warranted.

Docetaxel in advanced renal carcinoma. A phase II trial of the National Cancer Institute of Canada Clinical Trials Group.

BACKGROUND: Most patients diagnosed with renal carcinoma developed metastatic disease at some time during their course, with available therapy inducing response in only a small proportion of patients. Docetaxel (Taxotere, RP56976) a semi-synthetic analogue of paclitaxel with a broad range of in vitro antitumor activity, was evaluated in a phase II study. METHODS: Eligibility criteria included histologically proven metastatic or advanced, bidimensionally measurable disease, no prior chemotherapy, immunotherapy, or hormonal therapy, adequate hematologic (neutrophils > or = 2.0 x 10(9)/L, platelets > or = 100 x 10(9)/L) and biochemical (serum creatinine and bilirubin < or = 1.5 x normal, transaminases < or = 3 x normal) parameters, WHO performance status of at least 2, and a life expectancy of > 12 weeks. Docetaxel was administered in a dose of 100 mg/m2 as a 1 hour intravenous infusion every 3 weeks. The first 2 patients entered onto the study were not premedicated for hypersensitivity reactions; subsequent patients received dexamethasone 10 mg and diphenhydramine 50 mg i.v. 30 minutes prior to docetaxel. RESULTS: Twenty patients were entered onto the study, with 2 considered inevaluable for response. Sixty cycles of therapy were administered, with only 2 cycles delivered at a dose of 55 mg/m2 or less. No objective responses were seen; 1 patient demonstrated a mixed response. Neutropenia was significant, with 42/60 cycles developing grade 3/4 granulocytopenia. Fifty-five percent of patients demonstrated hypersensitivity reactions despite the premedication regimen employed, higher than that of the phase I studies which established the dose and schedule used in this trial. CONCLUSIONS: 1) Docetaxel is an ineffective agent in advanced renal carcinoma. 2) The high rate of hypersensitivity reactions suggests the need for more intensive premedication and/or slower infusion times at this dose level.

Phase II study of weekly edatrexate as first-line chemotherapy for metastatic breast cancer: a National Cancer Institute of Canada Clinical Trials Group study.

PURPOSE: The National Cancer Institute of Canada (NCIC) Clinical Trials Group conducted a phase II study to assess the efficacy and toxicity of edatrexate, a folate antagonist, in 35 patients with metastatic breast cancer. PATIENTS AND METHODS: The planned dose of edatrexate was 80 mg/m2/wk administered intravenously as first-line therapy. Prior adjuvant chemotherapy was allowed provided at least 12 months had elapsed from the completion of treatment to the development of recurrence. RESULTS: Mucositis was the dose-limiting toxicity in 34 assessable patients, resulting in a mean delivered dose-intensity of 57 mg/m2/wk. Other toxicities included myelosuppression, rash, pneumonitis, and increased AST. Side effects were generally mild to moderate. The complete plus partial remission rate (13 patients; 41%) was impressive. CONCLUSION: Edatrexate is an active agent against metastatic breast cancer, with acceptable toxicity. A lower than planned delivered dose-intensity was mainly due to mucositis.

Gemcitabine in advanced renal cell carcinoma. A phase II study of the National Cancer Institute of Canada Clinical Trials Group.

BACKGROUND: Gemcitabine (2', 2'-difluorodeoxycytidine; dFdC) an anticancer agent with activity in preclinical models, was felt to be a promising new chemotherapy drug which warranted testing in patients with advanced renal cell carcinoma. METHODS: Eighteen patients with histologically proven metastatic or locally recurrent renal cell carcinoma and bidimensionally measurable disease were accrued to a phase II study of gemcitabine administered intravenously on days 1, 8 and 15 of a 28 day treatment cycle. Initial doses of gemcitabine were 800 mg/m2; doses in subsequent cycles were escalated to a maximum of 1250 mg/m2, toxicity permitting. RESULTS: One partial response was seen for a response rate of 6%. Hematologic toxicity was not severe with this dosing schedule; however, two patients developed dyspnea with bronchospasm after repeated injections of drug. CONCLUSIONS: The dose and schedule of gemcitabine employed results in only a modest response rate in patients with advanced renal carcinoma. Investigators should be aware of the possibility of dyspnea and bronchospasm developing shortly after gemcitabine administration.