Cancer treatment reports最新文献

Azacitidine is a pyrimidine ring analog of cytidine that is incorporated into RNA causing alteration in RNA synthesis and processing and resulting in inhibition of protein synthesis. Azacitidine as the deoxynucleotide is also incorporated into DNA inhibiting its synthesis and blocking cytosine methylation by noncompetitive inhibition of DNA methyltransferase. The resulting hypomethylation of DNA is thought to induce gene activation and expression and cell differentiation. This may be an underlying factor in azacitidine's antileukemic activity and also contributes to its carcinogenic and tumor-promoting properties in experimental models.

A limited sampling model was developed for vinblastine to estimate the total area under the concentration time curve (AUC) using only two timepoints. Detailed pharmacokinetic analysis (16 timepoints) was performed in 30 patients treated with a small bolus dose (3 mg/m2) of vinblastine. A model for the total AUC was developed by multiple linear regression, using the first 15 patients as the training data set: AUC = 38.0 C10 + 73.8 C36 - 12.9, where C10 and C36 represent the serum vinblastine concentration at 10 hours and 36 hours, respectively (r = 0.99, P less than 0.0001). The model was validated on the other 15 patients, the test data set (r = 0.94, P less than 0.0001), with a mean predictive error of 13%. Limited sampling models may facilitate large-scale pharmacodynamic studies of new anticancer drugs, in order to relate the estimated AUC to toxicity and/or response without the need for detailed pharmacokinetic analysis.

Intravenous or oral cyclophosphamide, 150-250 mg/m2 (500 mg maximum), once per week with alternate-day oral prednisone, 100 mg, was given to 57 myeloma patients resistant to melphalan and prednisone (MP). Seven responses in 28 primary MP-resistant patients and ten responses in 29 secondary MP-resistant patients were observed. Previous response to MP was not a significant factor in predicting response to weekly cyclophosphamide and alternate-day prednisone. The results suggest that the regimen of weekly cyclophosphamide and alternate-day prednisone may be as effective as more aggressive regimens in the treatment of patients with myeloma who have failed MP therapy. However, a randomized trial would be required to determine the relative contributions of cyclophosphamide and prednisone to the effectiveness of this regimen.

Twenty-one evaluable patients with metastatic colorectal carcinoma were treated with a combination of continuous-infusion cisplatin (25 mg/m2/day X 3 days) and bolus 5-fluorouracil (400 mg/m2/day X 3 days). Toxicity was minimal. Seven patients (33%) responded. All responses were observed among the 16 previously untreated patients (44%) and lasted a median of 30 weeks. The results indicate the need for phase III trials of this treatment.

For two chemotherapy regimens to be truly non-cross-resistant, each should be active as first-line therapy and also as second-line therapy. The effectiveness of both cyclophosphamide, doxorubicin, and vincristine (CAV) and etoposide and cisplatin (VPP) in previously untreated patients with small cell lung cancer has been well-documented. Also, VPP has caused tumor regression in up to 50% of patients when used as second-line therapy after CAV. The effectiveness of CAV after progression or relapse after VPP has not been documented. We identified 29 patients who received CAV after their tumors failed to respond or relapsed after VPP or etoposide and carboplatin (VPC). There were 21 male and eight female patients (median age, 57 years; range, 30-79). Thirteen patients were treated following failure to respond to VPP or VPC and 16 at the time of relapse. Eight patients had limited disease and 21 had extensive disease. Metastatic sites included liver (11 patients), bone (ten), lymph nodes (seven), bone marrow (three), brain (four), and contralateral lung (one). There were three complete responses (durations of 16, 22, and 26 weeks) and five partial responses (duration, 8+ to 36 weeks). Three patients had stable disease and 18 patients had disease progression while receiving treatment. The median survival of the entire group was 15 weeks. Responding patients had a median survival of 34 weeks (range, 8+ to 72+) and stable and nonresponding patients had a survival of only 9 weeks (range, 2-38). A granulocyte count nadir less than 500 X 10(9)/L was seen after 7.9% of evaluable treatment cycles and a platelet count nadir less than 50,000 X 10(9)/L occurred after only 5.3% of cycles. Five patients required transfusion for anemia, and two patients required dose reduction of vincristine for peripheral neuropathy. This study demonstrates that CAV has limited activity following failure to respond to VPP.

The hypothesis that more selective antitumor activity may be achieved by cytotoxic agents which selectively bind to estrogen receptors (ER) in human cancer cells was tested. We have synthesized three nitrosourea derivatives of estradiol or hexestrol, and compared the ER binding affinity and cytotoxic activity of these compounds against ER-positive and -negative breast cancer cell lines in vitro. Specific binding to ER in the cytosol of MCF-7 human breast cancer cells was demonstrated in these conjugates: 17 alpha-CNU greater than 17 beta-CNU greater than HEX-CNU greater than lomustine (CCNU). The order of cytotoxicity of these derivatives against human breast cancer cells appeared to correlate with their binding affinity to ER. All three estrogen nitrosourea conjugates were more cytotoxic than CCNU, a clinically useful antitumor nitrosourea which does not bind to ER. The contribution of the estrogen moiety to the cytotoxicity of 17 alpha-CNU was demonstrated by the greater activity of the conjugate than that of a combination of estrogen and CCNU. However, cytotoxicity of these compounds against the receptor-positive MCF-7 and receptor-negative Evsa-T human breast cancer cell lines was similar. The latter finding suggested that cytotoxicity of these conjugates may not be mediated through ER. The difference in stability of these nitrosourea conjugates in aqueous buffer may partly explain their differences in cytotoxicity.

This study of 2382 breast, 182 rectal, 817 colon, and 351 lung cancer patients treated with combination chemotherapy on eight phase III Eastern Cooperative Oncology Group protocols indicates that 69% would receive a higher dose of at least one drug if surface area were calculated from actual weight rather than from the minimum of actual and ideal weight. Forty-eight percent of the patients would have at least a 10% increase in drug dose based on actual weight. Only on the premenopausal adjuvant breast cancer protocol and among women on the rectal adjuvant study do the differences in dose based on actual rather than ideal weight increase significantly with age. On the postmenopausal adjuvant breast study and on the lung cancer study, the differences in dose decrease significantly with age. For all age decades and both sexes within each protocol, the mean differences between dose based on actual and dose based on ideal weights were on the same order as the rounding factors for the 11 drugs studied. From the literature on the effect of doses of common chemotherapies on leukopenia, it appears that the percent of hematologic toxicity would not be raised to unacceptable levels by using actual weight to set doses.