[Multicenter randomized controlled study of temozolomide versus semustine in the treatment of recurrent malignant glioma]

OBJECTIVE

To evaluate the efficacy and safety of temozolomide (TMZ) versus semustine (Me-CCNU) in the treatment of recurrent glioblastoma multiforme (GBM) or anaplastic astrocytoma (AA).

METHODS

A total of 151 patients with recurrent GBM or AA were enrolled into this randomized, multicentre and open-label study. And 144 patients (intent-to-treat (ITT) population) were assigned randomly into 2 groups. TMZ was given orally at 200 or 150 mg×m(-2)d(-1) (prior chemotherapy) for 5 days, repeated every 28 days. Me-CCNU was given orally at 150 mg×m(-2)×d(-1) once, repeated every 28 days. The treatment periods were within 2 - 6 months and the follow-up period was 6 months. Gadopentetate dimeglumine-magnetic resonance imaging (GD-MRI) or contrast-enhanced computed tomography was performed at 2, 3 and 6 months after treatment to evaluate the image-based progression. Progression-free survival (PFS), overall survival rates at the end of follow-up period and adverse events rates were evaluated.

RESULTS

PFS at 6 months was 78.87% in TMZ group and 55.88% in Me-CCNU group (P < 0.05). Overall survival rates at the end of follow-up period were 96.89% in TMZ group and 97.30% in Me-CCNU group (P > 0.05). The objective response rate of TMZ and Me-CCNU groups were complete response (CR) (19.44% vs 6.38%), partial response (PR) (26.39% vs 14.89%), stable disease (SD) (26.39% vs 34.03%) and progressive disease (PD) (27.78% vs 44.68%, P < 0.01). Adverse events rates of TMZ and Me-CCNU were 29.11% and 45.15% respectively (P < 0.05).

CONCLUSION

The efficacy of TMZ for patients with recurrent GBM or AA is better than that of Me-CCNU. And TMZ has an acceptable safety profile and its adverse events are mostly mild.

Candidate genes influencing sensitivity and resistance of human glioblastoma to Semustine

OBJECTIVE

The prognosis of glioblastoma (GBM) is poor. The therapeutic outcome of conventional surgical and adjuvant treatments remains unsatisfactory, and therefore individualized adjuvant chemotherapy has aroused more attention. Microarrays have been applied to study mechanism of GBM development and progression but it has difficulty in determining responsible genes from the plethora of genes on microarrays unrelated to outcome. The present study was attempted to use bioinformatics method to investigate candidate genes that may influence chemosensitivity of GBM to Semustine (Me-CCNU).

METHODS

Clinical data of 4 GBM patients in Affymetrix microarray were perfected through long-term follow-up study. Differential expression genes between the long- and short-survival groups were picked out, GO-analysis and pathway-analysis of the differential expression genes were performed. Me-CCNU-related signal transduction networks were constructed. The methods combined three steps before were used to screen core genes that influenced Me-CCNU chemosensitivity in GBM.

RESULTS

In Affymetrix microarray there were altogether 2018 differential expression genes that influenced survival duration of GBM. Of them, 934 genes were up-regulated and 1084 down-regulated. They mainly participated in 94 pathways. Me-CCNU-related signal transduction networks were constructed. The total number of genes in the networks was 466, of which 66 were also found in survival duration-related differential expression genes. Studied key genes through GO-analysis, pathway-analysis and in the Me-CCNU-related signal transduction networks, 25 core genes that influenced chemosensitivity of GBM to Me-CCNU were obtained, including TP53, MAP2K2, EP300, PRKCA, TNF, CCND1, AKT2, RBL1, CDC2, ID2, RAF1, CDKN2C, FGFR1, SP1, CDK6, IGFBP3, MDM4, PDGFD, SOCS2, CCNG2, CDK2, SDC2, STMN1, TCF7L1, TUBB.

CONCLUSION

Bioinformatics may help excavate and analyze large amounts of data in microarrays by means of rigorous experimental planning, scientific statistical analysis and collection of complete data about survival of GBM patients. In the present study, a novel differential gene expression pattern was constructed and advanced study will provide new targets for chemosensitivity of GBM.

Chemoradiotherapy in patients with anal cancer: impact of length of unplanned treatment interruption on outcome

The aim of this retrospective analysis was to evaluate feasibility and effectiveness of definitive chemoradiotherapy without split-course technique in anal cancer patients. From 1993 to 2003, 81 patients were treated; 13 were excluded due to various chemotherapeutic regimes, thus 68 patients were analysed. In case of acute grade 3 toxicities, treatment was halted until improvement or resolution independent of dose. Short interruption was defined as completing treatment without exceeding eight cumulative treatment days beyond scheduled plan, other patients were considered to have had prolonged interruption. Median follow-up was 46 months. Median overall treatment time was 53 days corresponding to an interruption of eight cumulative treatment days. Thirty-five patients (51%) had treatment interruption of <or=8 days. No acute grade 4 toxicities were observed; one fatality occurred during treatment due to ileus-like symptoms according to acute grade 5 toxicity. Comparing patients with short vs. prolonged interruption 5-year actuarial rates for local control were 85% vs. 81% (p = 0.605) and for colostomy-free survival 85% vs. 87% (p = 0.762), respectively. Chemoradiotherapy with short individualised treatment interruptions seems to be feasible with acceptable acute or late toxicities. Treatment is highly effective in terms of local control and colostomy-free survival.

Surveillance renal transplant biopsies and subclinical rejection at three months post-transplant in pediatric recipients

Subclinical acute rejection (SCR) has been increasingly recognized in adult renal transplant recipients with the advent of surveillance biopsies. However, in children, surveillance biopsies are not routinely performed at most centers. Therefore, the incidence, predisposing factors, treatment, and clinical outcomes of SCR remain unclear in children. From August 2004 to December 2005, we performed 36 protocol biopsies at three months post-transplantation. All patients had received induction therapy with basiliximab and were maintained on prednisone, MMF, and tacrolimus. Sixteen cases of SCR were detected by biopsy (44%). Age, gender, race, donor source, or serum creatinine did not discriminate between children with SCR and those with normal biopsies. All cases of SCR were treated with high doses of methylprednisolone. At one yr post-transplant, renal function was similar in children with SCR to those with normal surveillance biopsies (p = 0.62). Because of the high incidence of SCR, the maintenance dose of MMF was increased by 50% in 20 children transplanted after December 2005. This resulted in a significant decline in the incidence of SCR from 44 to 15% (p < 0.05). However, the incidence of polyomavirus (BK) viremia also increased significantly in these children (p < 0.005).

CONCLUSION

A high incidence of SCR was found on surveillance biopsies at three months post-transplant and could not be predicted by age, gender, race, donor source, or serum creatinine. The occurrence of SCR declined significantly by increasing the dose of MMF, but resulted in an increase in BK viremia. We conclude that surveillance biopsies provide valuable information in the management of pediatric renal transplant recipients. Increasing immunosuppression to avoid SCR should be weighed against the risk for infection.

[Radiotherapy and chemotherapy in the treatment of cancer of the rectum]

The North American consensus conference held in 1990 concluded that the best currently available adjuvant treatment for cancer of the rectum (T3, N1 to N3) was postoperative combination radiotherapy and chemotherapy. In 1994, the consensus conference held in Paris concluded that the benefit observed after preoperative irradiation warranted assessment of the effect of preoperative radiochemotherapy. To decide between these two consensus conclusions, it would be most logical to compare preoperative radiotherapy with postoperative radiochemotherapy in a group of patients with similar echo-endoscopic or imaging findings.

[Developments up to now and current status of adjuvant chemo- and radiotherapy in colonic and rectal carcinoma]

A review is given of the historical and current concepts of adjuvant chemo- and radiotherapy of colorectal cancer. Early studies analyzing the use of single drug regimens were followed by a second study generation investigating adjuvant chemotherapeutic combinations. 5-FU proved to be the most efficient single drug investigated and 5-FU/MeCCNU/vincristin the most efficient chemotherapeutic combination, but no significant improvement in 5-year survival rates was achieved. Clear progress was noted with the introduction of levamisol (LEV) for modulation of 5-FU. A 33% improval in the 5-year survival rate in patients with stage III colon carcinoma was documented. It was therefore recommended (NIH consensus conference 1990) that all patients with stage III colon carcinoma be treated with this regimen unless admitted to other trials of adjuvant therapy. Preoperative radiotherapy with a dosage of 35-45 Gy can lead to downstaging of rectal cancer. Nevertheless, significant improvement in patient survival has not been proved convincingly using either isolated pre- or postoperative adjuvant radiotherapy. However, combined radiochemotherapy has been shown to improve both patient survival and local tumor control compared to surgical resection alone. It is therefore recommended that all stage II and III rectal cancer patients be treated with adjuvant combined radiochemotherapy. 5-FU/MeCCNU is currently expected to be the most efficient chemotherapy in combination with radiotherapy. Early data point out that MeCCNU could possibly be omitted. Intraoperative radiotherapy (IORT) allows further dosage escalation in order to improve local tumor control without affecting radiosensitive structures. Available data are still sparse and mostly based on the treatment of advanced carcinoma. A general validation of IORT is not yet possible, but current data are promising.

Improving adjuvant therapy for rectal cancer by combining protracted-infusion fluorouracil with radiation therapy after curative surgery

BACKGROUND

The combination of radiation therapy and chemotherapy with fluorouracil plus semustine after surgery has been established as an effective approach to decreasing the risk of tumor relapse and improving survival in patients with rectal cancer who are at high risk for relapse or death. We sought to determine whether the efficacy of chemotherapy could be improved by administering fluorouracil by protracted infusion throughout the duration of radiation therapy and whether the omission of semustine would reduce the toxicity and delayed complications of chemotherapy without decreasing its antitumor efficacy.

METHODS

Six hundred sixty patients with TNM stage II or III rectal cancer received intermittent bolus injections or protracted venous infusions of fluorouracil during postoperative radiation to the pelvis. They also received systemic chemotherapy with semustine plus fluorouracil or with fluorouracil alone in a higher dose, administered before and after the pelvic irradiation.

RESULTS

With a median follow-up of 46 months among surviving patients, patients who received a protracted infusion of fluorouracil had a significantly increased time to relapse (P = 0.01) and improved survival (P = 0.005). There was no evidence of a beneficial effect in the patients who received semustine plus fluorouracil.

CONCLUSIONS

A protracted infusion of fluorouracil during pelvic irradiation improved the effect of combined-treatment postoperative adjuvant therapy in patients with high-risk rectal cancer. Semustine plus fluorouracil was not more effective than a higher dose of systemic fluorouracil given alone.

Long term response to chemotherapy in patients with visceral metastatic melanoma

PATIENTS AND METHODS

Eight patients who remain in long term remission 4 to 15 years after chemotherapy for visceral metastatic melanoma are described. These patients were observed among some 1100 patients with visceral melanoma seen at the Sydney Melanoma Unit between 1977 and 1989. Only about one-third of such patients received chemotherapy, almost always with single agent dacarbazine or a nitrosourea.

RESULTS

The apparently cured patients did not differ from the overall group of patients with visceral metastases in baseline characteristics, but 6 of the 8 had nodular lung metastases.

CONCLUSIONS

While the mechanism remains uncertain, one possibility could be that chemotherapeutic agents cause mutations which allow expression of antigenicity in tumour cells. In any case, the fact of occasional exceptionally good responses, perhaps amounting to cure, constitutes an argument for a trial of chemotherapy in patients with visceral metastatic melanoma.

Schedule dependent potentiation of antitumor drug effects by alpha-difluoromethylornithine in human gastric carcinoma cells in vitro

A clone of human gastric cancer cells (AGS-6) and the parental line (AGS-P) from which it was isolated were used in cell survival studies to determine whether pretreatment for 24, 48 or 72h with alpha-difluoromethylornithine (DFMO, 5mM) would increase the cell's sensitivity to 5-Fluorouracil (5FU), Adriamycin (Adria), 1-(2-chloroethyl)-3-(4-methyl cyclohexyl)-1-nitrosourea (MeCCNU), or Bleomycin (Bleo). Generally, the AGS parental cells were most sensitive to the anticancer agents after exposures to DFMO. However, there was no way to predict in advance from DFMO-induced changes in ornithine decarboxylase (ODC), polyamine or cell kinetics values, how long an exposure to DFMO was required before sensitization to an anticancer agent occurred. The degree of potentiation for a single drug was variable from time to time during exposure to DFMO, and broad differences in the sensitizations were demonstrated among the four anticancer drugs. The AGS-6 clone exhibited little or no increased sensitivity as a result of pretreatment with DFMO, even though the DFMO-induced reductions in ODC and polyamine values in these cells were similar to those produced in the more sensitive parental line.

Priming with low doses of methyl-CCNU reduce the toxicity of high doses of methyl-CCNU and melphalan, and increase the lifespan of mice implanted with Lewis lung carcinoma

Pretreatment of mice with low doses of methyl-CCNU was shown to reduce the toxicity of lethal doses of methyl-CCNU or melphalan administered one or two days following the low dose. There was an increase in survival rate, body weight, thymus and kidney wet weight. Tissue morphology was less affected in the primed mice as compared to mice receiving the high dose or a high-low dose combination. In mice implanted s.c. with Lewis lung carcinoma, priming with 5 mg kg-1 methyl-CCNU 2 days before injection of a very high (35 mg kg-1) dose significantly increased the lifespan as compared to treatment with the high dose alone or with high-low dose combination. When the dose of methyl-CCNU was further increased to 40 mg kg-1 toxic death occurred, which was, however, significantly reduced by 'priming' with the low dose given. When low-high dose combination was used twice (the high dose was given on day 7 or 9, and 18 or 20 after tumour inoculation), priming with 5 mg kg-1 (but not with 10 mg kg-1) two days prior to the high dose was beneficial in reducing toxic death (in two experiments) and either increasing lifespan or not significantly increasing it. In no case was there protection of the tumour by the low-high dose combinations.

The effect on survival of initial chemotherapy in advanced breast cancer: polychemotherapy versus single drug

Since current clinical trials assessing new agents occur in patients with advanced breast cancer having failed one and sometimes many polychemotherapy programs, these new agents may not be given a fair trial. In an effort to assess the possibility of using an alternative study design, we analyzed older clinical trials that used a controlled study design, randomizing between a single new drug and an established polychemotherapy program with a cross-over design upon failure. We were interested in noting that the pooled data did display a slight survival advantage (median 3.7 months) for the group receiving polychemotherapy as initial therapy. The survival distributions were clearly not significant using the log rank test, but did approach significance using the Smirnov. It is apparent that, while some slight advantage does occur for that group of patients receiving initial polychemotherapy, the magnitude of this effect is not great and is short in duration. Serious consideration should be given to the assessment of new agents as first-line therapy, particularly should they have a unique mode of action or lessened morbidities or toxicities.

Phase II evaluation of dibromodulcitol and actinomycin D, hydroxyurea, and cyclophosphamide in previously untreated patients with malignant melanoma

In this Eastern Cooperative Oncology Group (ECOG) phase II study, dibromodulcitol (DBD) and a combination of actinomycin D, hydroxyurea, and cyclophosphamide (AHC) were compared with methyl-CCNU, the current ECOG standard, in patients who had received no prior chemotherapy for disseminated malignant melanoma. The response rates were 6% (3/50) for AHC, 9% (3/34) for DBD, and 14% (7/49) for methyl-CCNU. Median survival times were 4, 5, and 6 months, respectively. Neither regimen appears to offer any advantage over methyl-CCNU as front-line therapy for patients with disseminated melanoma.

A randomized clinical trial of combination chemotherapy in advanced colorectal cancer

One hundred and sixty-five patients with advanced colorectal cancer were entered into a prospectively randomized trial of combination chemotherapy comparing three 5-fluorouracil plus methyl CCNU (FM)-based regimens: FM plus ICRF-159 (FMI), FM plus triazinate (FMT), and FM plus vincristine (FMV). Patients were stratified according to performance status, anatomic site of primary indicator lesion, and prior chemotherapy. Those with abnormal kidney or liver function were randomized between FMI and FMV because triazinate depends on both hepatic and renal mechanisms for elimination. There were no significant differences between the treatment regimens in objective response rate (11%-17%), interval to progression (median, 10-14 weeks), or survival (median, 5-6 months). The primary side effect observed was hematologic toxicity, which tended to increase in severity with repeated courses of therapy. Although ICRF-159 and triazinate have been shown to have limited single-agent phase II activity against colorectal cancer in previous trials, neither agent combined with 5-fluorouracil plus methyl CCNU has an improved treatment effect compared with FMV. We do not recommend the further use of these regimens in the treatment of advanced colorectal cancer.

Development of MeCCNU-resistance in clonally derived lines of Lewis lung carcinoma

The development of resistance to MeCCNU in four clonal lines of Lewis lung carcinoma derived from lung colonies has been examined. Treatment of the clones with 15 mg/kg MeCCNU once in each in vivo passage resulted in a rapid reduction in tumour responsiveness to this drug. This shows that MeCCNU resistance can arise at rates which may be applicable in spontaneous tumours and their metastases. Karyotypic heterogeneity was evident very early after isolation of the clones and this has potentially important implications for the experimental use of clones and for the features of metastatic disease. Karyotype analysis of one of the clones at each passage suggested that development of resistance was associated with the selection of a single sub-population of tumour cells but the kinetics of resistance development cannot be totally explained in terms of this simple selection.

Glutathione and related enzymes in rat brain tumor cell resistance to 1,3-bis(2-chloroethyl)-1-nitrosourea and nitrogen mustard

Reduced glutathione (GSH) and activities of several glutathione-related enzymes were measured in two 9L rat brain tumor cell lines with differing sensitivities to both 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) and nitrogen mustard. GSH, measured by a specific high-performance liquid chromatographic method, was found to be approximately twice as high in 9L cells sensitive to BCNU but resistant to nitrogen mustard. The nitrogen mustard resistant cell line was also found to have 2.5-fold more bulk glutathione transferase activity and approximately 3-fold more gamma-glutamyl transpeptidase activity. Glutathione reductase activity, protein thiol, and total protein content were similar in the two cell lines. Pretreatment of 9L cells with 50 microM buthionine sulfoximine for 24 h to deplete GSH only slightly potentiated BCNU cytotoxicity in a clonogenic assay whereas that of nitrogen mustard was markedly potentiated in both cell lines. Similarly, buthionine sulfoximine pretreatment had little effect on the induction of sister chromatid exchanges by BCNU, but significantly increased the number of sister chromatid exchanges induced by nitrogen mustard in both cell lines. Depleting GSH also had no significant effect on the cytotoxicity of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea and 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea to 9L cells. Pretreatment of 9L cells with 1 mM GSH significantly protected against nitrogen mustard cytotoxicity. Moreover, nitrogen mustard incubated with GSH and glutathione transferase was 4-fold less cytotoxic than nitrogen mustard incubated with GSH alone. Incubation of BCNU with GSH alone or with glutathione transferase had no effect on BCNU cytotoxicity. These results indicate that elevated GSH and glutathione transferase activity is one mechanism of cellular resistance to nitrogen mustard in the 9L cell line, but it does not correlate with resistance to BCNU or other clinically important nitrosoureas.

Enhancement of semustine-induced cytotoxicity by chlorpromazine and caffeine in a human melanoma xenograft

Chlorpromazine (CPZ) and caffeine (CFN) enhance the cytotoxicity of nitrosoureas in conventional murine tumor systems, but this effect was not confirmed in a randomized clinical trial which compared the action of semustine (MeCCNU) against the combination of MeCCNU, CPZ, and CFN. Since differences in repair systems are known to exist between cells of human or murine origin, we have employed a human melanoma xenograft system to quantify the drug interaction. The enhancement in human melanoma cells was similar to that observed with conventional murine tumor systems. Alkaline elution studies and determination of radioactivity from labeled MeCCNU pointed to increased drug retention and fixation of DNA damage as the mechanism of enhancement. Although toxicity studies were limited to murine tissues, there was evidence of increased toxicity, especially if MeCCNU was combined with both CPZ and CFN. Thus, a true therapeutic synergism may not be present for the combination. Some explanations for the failure to detect such drug interaction in clinical trials and the relevance of advanced preclinical tumor systems are discussed.

Effect of Fluosol-DA/O2 on tumor-cell and bone-marrow cytotoxicity of nitrosoureas in mice bearing FSA-II fibrosarcoma

The perfluorochemical emulsion, Fluosol-DA, combined with carbogen breathing, potentiates the effects of radiation and a number of chemotherapeutic agents in several rodent tumors. The interaction of Fluosol-DA with drugs may be quite complex. In addition to increasing the oxygen supply in the tumor, Fluosol-DA may alter the pharmacokinetics of the drug and function as a drug delivery system. A series of 4 nitrosoureas of varying lipophilicity were administered as single doses intravenously (i.v.) to C3H/Be/FeJ mice bearing subcutaneous FSa-IIC fibrosarcomas. Doses of 40 mg/kg of CCNU, 15 mg/kg of BCNU, 20 mg/kg of MeCCNU and 15 mg/kg of chlorozoticin followed by 2 hr of breathing 95% oxygen produced tumor growth delays of 7.5, 4.0, 3.8 and 2.7 days, respectively. When the drug injection was followed immediately by 0.3 ml of Fluosol-DA and 2 hr of breathing 95% oxygen, the tumor growth delay produced by CCNU, BCNU, MeCCNU and chlorozoticin increased 2-fold, 10-fold, 4.5-fold and 3.5-fold, respectively. Administration of the drugs in Fluosol-DA followed by 2 hr of 95% oxygen breathing resulted in a 3.5-fold increase in tumor growth delay with CCNU, a 17-fold increase with BCNU, a 12.5-fold increase with MeCCNU and a 6-fold increase with chlorozoticin compared to drug and 95% oxygen breathing. These results are quantified in terms of cell survival by the tumor excision assay. Effects on the bone marrow from each treatment were measured using the granulocyte-monocyte colony-forming units (CFU-GM) assay. There was no correlation between the lipophilicity of the nitrosoureas tested and the tumor growth delay produced by each treatment.

Biphenotypic leukemia with unusual chromosomal translocation in a patient treated for melanoma

A patient in complete remission from malignant melanoma but with refractory anemia after nitrosourea treatment developed acute biphenotypic leukemia. This disease, progression was accompanied by expansion of a cytogenetically abnormal clone. At first cytogenetic analysis, 1 year post discontinuation of chemotherapy, only 25% of the metaphases examined were hypodiploid with monosomy 7. Six months later, all of the metaphases seen were 45,XY,-7. Six months before overt acute leukemia was diagnosed, an additional chromosome abnormality emerged, t(2;3)(q31;q27). Although the translocation was present in all metaphases examined, the patient progressed into an acute leukemia with two components: one TdT-positive, Ia-positive, and the other TdT-negative, Ia-positive, monocytoid antigen-positive. This mixed leukemia was identified by double fluorescence staining for intranuclear TdT and surface labeling with a monocyte-specific monoclonal antibody.

Emergence of nitrosourea resistant sublines of Lewis lung tumour following MeCCNU treatment in vivo

Several different drug retreatment protocols were employed to examine the emergence of resistance to MeCCNU in Lewis lung tumours. Previous studies suggested that although the majority of cells in untreated Lewis lung tumours were sensitive to MeCCNU, there was a very small proportion of resistant cells (approximately 0.001%) that limited "tumour cure' with that drug. If such cells were inherently drug resistant then it should be possible to derive highly resistant tumours by repeated drug treatment. In the first experiment tumours were treated with a single high dose of MeCCNU (35 or 40 mgkg-1) and on regrowth, transplanted into fresh mice and tested for drug sensitivity. Using both excision cell survival and growth delay endpoints, only approximately 25% of tumours were significantly resistant to the test dose, suggesting that many tumours resist the effects of the drug for reasons other than the presence of inherently drug resistant cells. One of the tumours (R4), that regrew after the initial treatment and appeared to be resistant to the test treatment, was retreated with a further 30 mgkg-1 MeCCNU and became more resistant. This line, designated R4/1, was cross-resistant to the other nitrosoureas, BCNU and CCNU, but not to cyclophosphamide, melphalan, cis-platinum or ionising radiation. The effect of treatment dose on the kinetics of MeCCNU resistance development was also studied in a retreatment regimen where the tumours were allowed to regrow and then transplanted into fresh hosts for the next treatment. Resistance developed more quickly at an intermediate dose of 15 mgkg-1 than at 7.5 mgkg-1 where the selective pressure was lower, or at 30 mgkg-1 where there was probably extinction of partially resistant cells. Resistance to MeCCNU developed even more quickly when tumours were retreated several times in the same host, although in a similar experiment with cyclophosphamide no resistance occurred.

Methyl-CCNU and methotrexate therapy in patients with advanced colorectal cancer after failure of 5-fluorouracil chemotherapy

Thirty-six patients with advanced colorectal cancer whose disease progressed during treatment with 5-fluorouracil (5-FU) chemotherapy were treated with methyl-CCNU and methotrexate. Five patients (14%) achieved a partial response (PR), three (8%) showed disease regression less than that required for a PR, and three (8%) showed evidence of stable disease. Twenty-five patients (69%) progressed on treatment. Tumor regression was seen only in patients with good performance status (ECOG 0.1). The median survival time of patients achieving a PR was 31 weeks. Those patients with stable disease or disease regression less than a PR had median survival times of 49 and 32 weeks, respectively. The comparable figure for those patients with disease progression was 17 weeks. Myelosuppression, principally in the form of leukopenia and thrombocytopenia, was common. Nausea and vomiting were universal with methyl-CCNU, and mucositis and diarrhea occurred commonly due to methotrexate. These results demonstrate the limited activity of chemotherapy in refractory colorectal cancer. They also reaffirm that poor pretreatment performance status should exclude patients from futile attempts at palliative therapy or phase II clinical trials, as these patients derive little or no benefit from them.

Combined 5-fluorouracil (5-FU) and radiation therapy following resection of locally advanced gastric carcinoma

Twenty-five patients with locally advanced but resectable adenocarcinoma of the stomach were given concomitant postoperative radiotherapy to the tumor bed and chemotherapy with 5-Fluorouracil (5-FU). Twenty-two of the patients had regional lymph node involvement and seven had residual tumor in the surgical margins. Radiotherapy was delivered to a total dose of 5,000 rads in 7 weeks with a two-week split. 5-FU was given daily the first 3 days of each treatment period and was then continued weekly for a minimum of 1 year. At a median follow-up time of 19 months, 11 patients have relapsed, two locally and nine distally, and all have died. Thirteen patients remain alive, all but one disease-free, for a median of 21 months from diagnosis. One additional patient died of unrelated causes, free of tumor. The actuarial median survival for the whole group stands at 33 months with a projected 5-year survival of 40%. Treatment has been well tolerated.

Cure rates and tumor resistance in cured mice after nitrosourea treatment of EMT6 ascites tumors

Single-dose BCNU or chlorozotocin (CLZ) treatment of EMT6 mammary carcinoma tumors of the BALB/c mouse has only a transient effect on tumor growth, after which tumors follow control growth patterns. To test the hypothesis that drug access to tumor cells might be a factor in cell killing, we adapted the EMT6/KY tumor to ascites form. Injection of 10(5) EMT6/KY cells i.p. kills BALB/c mice with a mean survival time of 13.0 +/- 1.0 days. We have surveyed several nitrosoureas for their effects on the EMT6/KY ascites tumor after intraperitoneal injection of the drugs. Cure rates and percent increase in life span were used as endpoints. Also, we tested for induced host tumor resistance (TR) in cured mice, by challenging survivors with live EMT6 cells. Highest cure rates were obtained for treatment on days 2, 3, or 4 after inocula of 10(5) cells: CLZ (10 mg/kg), 83.3%; cis-acid (20 mg/kg), 75%, and CCNU (30 mg/kg), 70%. Other nitrosoureas, i.e. BCNU, PCNU, GANU, STZN, FCNU, ACNU, MeCCNU, NSC-88104 produced lower cure rates. Cured mice surviving challenges of 10(6) EMT6 cells were considered TR. TR mice did not correlate with cure rates for the 3 nitrosoureas giving high cure rates. As percent of survivors, TR mice were (for day 3 treatment): FCNU, 100%, BCNU, 100.0% and CLZ, 50.0%. Thus, cure rates and TR seem to depend on the structure of the nitrosourea, but through different mechanisms.

Management of cancer in the elderly. Implications of the aging process

Cancer is one of the most serious illnesses of the elderly. Screening programs focusing on its early detection in this age-group are needed to allow maximum opportunity for cure. Also important is convincing the older patients who smoke that stopping is still worthwhile. Compared with younger patients, the elderly have more intercurrent medical illnesses and are more likely to suffer from financial difficulties and loss of family support. These factors must be considered when managing these patients. Although age-imposed compromises in treatment are often made, available data suggest that a priori dose reduction of chemotherapy on the basis of age alone is not indicated in patients with solid tumors. Prospective clinical trials are needed to further address the issue of responsiveness to chemotherapy as a function of age. Such trials should include assessment of physiologic age and quality of life.

O6-Alkylguanine-DNA alkyltransferase activity correlates with the therapeutic response of human rhabdomyosarcoma xenografts to 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea

Immune-deprived female CBA/CaJ mice bearing xenografts of six different human rhabdomyosarcoma lines were treated with 1-(2-chloroethyl)-3-(trans-4-methylcyclohexyl)-1-nitrosourea (MeCCNU). Tumor responses were compared with levels of O6-methylguanine-DNA methyltransferase activity because of evidence indicating that repair of DNA interstrand cross-link precursors, mediated by the transferase, may be an important determinant of MeCCNU cytotoxicity. Levels of methyltransferase in tumor extracts were measured by determining the loss of O6-methylguanine from 3H-labeled methylated DNA. Five of the six tumor lines examined showed either no response to MeCCNU or regrowth after an incomplete response. In each instance, the extent of tumor regression correlated with the level of O6-methylguanine-DNA methyltransferase activity in tumor extracts. The single highly drug sensitive line was totally devoid of the activity. These results suggest that O6-methylguanine-DNA methyltransferase levels in human tumor cells may be a clinically useful predictor of sensitivity to the chloroethylnitrosoureas.

Eastern Cooperative Oncology Group experience with chemotherapy for inoperable gallbladder and bile duct cancer

In a prospective randomized Eastern Cooperative Oncology Group (ECOG) study, 53 eligible and evaluable patients with advanced gallbladder carcinoma and 34 with advanced bile duct carcinoma were treated with oral 5-fluorouracil (5-FU) or with oral 5-FU plus streptozotocin (Stz) or oral 5-FU + Methyl-CCNU (MeCCNU). Severe toxicity occurred in 2 of 30 patients receiving 5-FU (7%), in 14 of 26 receiving 5-FU + Stz (54%), and in 12 of 31 receiving 5-FU + MeCCNU (39%). Five of 53 patients with gallbladder carcinoma (2/18 [11%] on 5-FU, 2/16 [12%] on 5-FU + Stz, and 1/19 [5%] on 5-FU + MeCCNU) had objective response to treatment. There was no significant difference between treatments with respect to response or survival. Three of 34 patients with bile duct cancer (1/12 [8%] on 5-FU, 0/10 on 5-FU + Stz, and 2/12 on 5-FU + MeCCNU) had objective response to treatment. There was no significant difference between treatments with respect to response or survival. Patients with prior chemotherapy were randomized between MeCCNU alone and Stz alone. Among such patients, only 1 of 17 patients who had prior chemotherapy with other agents responded to MeCCNU alone, and none of 14 patients responded to Stz alone.

Primary liver cancer. An Eastern Cooperative Oncology Group Trial

One hundred ninety-two patients with unresectable primary liver cancer studied by members of the Eastern Cooperative Oncology Group (ECOG) were evaluable in a prospectively randomized clinical trial. Patient discriminants such as performance status were carefully evaluated to assess their influence on prognosis and to evaluate the importance of patient status on response and survival. Patients who were totally bedridden or with signs of overt liver failure were not entered on study. The median survival time for all evaluable previously untreated patients was 17 weeks (19 weeks for North American and European, and 10 weeks for South African black patients). Among the South African patients, however, there was a significantly larger proportion with an initially poor performance status. Prognostic variables (performance status, jaundice, and reduced appetite) dominate any differences among the treatments studied. Among North American and European patients on intravenous (IV) 5-fluorouracil (5-FU) + Methyl-CCNU (MeCCNU) + Adriamycin (ADM, doxorubicin), the 19% response rate is offset by 63% with severe toxicity and a median survival time of only 17 weeks, making this treatment unacceptable clinically. The median survival time of North American and European patients treated with IV 5-FU +/- MeCCNU was 28 weeks in contrast to a median survival time of 12 weeks with ADM (P less than or equal to 0.01). EST 2273 was the ECOG study of patients with primary liver cancer. The results of the first part of the trial were published in 1978. This report updates those findings and reports the results of patients entered subsequently on the second part of that study after it was amended in 1979. With more than 300 evaluable patients in EST 2273, this duet of studies is the largest ever conducted in patients with primary liver cancer, and draws a new baseline from which to measure the disease and its response to treatment.

Eastern Cooperative Oncology Group experience with chemotherapy for inoperable gallbladder and bile duct cancer

In a prospective randomized Eastern Cooperative Oncology Group (ECOG) study, 53 eligible and evaluable patients with advanced gallbladder carcinoma and 34 with advanced bile duct carcinoma were treated with oral 5-fluorouracil (5-FU) or with oral 5-FU plus streptozotocin (Stz) or oral 5-FU + Methyl-CCNU (MeCCNU). Severe toxicity occurred in 2 of 30 patients receiving 5-FU (7%), in 14 of 26 receiving 5-FU + Stz (54%), and in 12 of 31 receiving 5-FU + MeCCNU (39%). Five of 53 patients with gallbladder carcinoma (2/18 [11%] on 5-FU, 2/16 [12%] on 5-FU + Stz, and 1/19 [5%] on 5-FU + MeCCNU) had objective response to treatment. There was no significant difference between treatments with respect to response or survival. Three of 34 patients with bile duct cancer (1/12 [8%] on 5-FU, 0/10 on 5-FU + Stz, and 2/12 on 5-FU + MeCCNU) had objective response to treatment. There was no significant difference between treatments with respect to response or survival. Patients with prior chemotherapy were randomized between MeCCNU alone and Stz alone. Among such patients, only 1 of 17 patients who had prior chemotherapy with other agents responded to MeCCNU alone, and none of 14 patients responded to Stz alone.

Chemotherapy of advanced colorectal carcinoma: fluorouracil alone vs. two drug combinations using fluorouracil, hydroxyurea, semustine, dacarbazine, razoxane, and mitomycin. A phase III trial by the Eastern Cooperative Oncology Group (EST: 1278)

Patients with advanced colorectal cancer and no prior chemotherapy were randomized to six treatment regimens: A) fluorouracil (FU) alone; B) FU + hydroxyurea (HU); C) semustine (SE) + dacarbazine (DA); D) FU + HU alternating with SE + DA; E) SE + razoxane (RA); F) mitomycin (MI) + DA. There were no significant treatment differences with respect to response, which ranged from 9-23% (overall 32/207 or 15%) or median survival duration, which ranged from 17 weeks to 32 weeks. Patients treated with FU or FU + HU experienced substantially less toxicity than those on the other treatment arms.

Identification of a subpopulation of MeCCNU resistant cells in previously untreated Lewis lung tumours

A variety of experimental endpoints including excision cell survival, lung colony curability, tumour regrowth delay and i.m. tumour curability following MeCCNU alone and combined with gamma-radiation, were used to define the MeCCNU cell survival curve down to "tumour cure" level in previously untreated i.m. Lewis lung tumours. The survival curve was found to be biphasic, the tumour cells being markedly resistant to MeCCNU at high doses of the drug. Below 10 mg kg-1 the survival curve was exponential through the origin with a D10 of approximately 2 mg kg-1, while above 15 mg kg-1 the D10 was approximately 25 mg kg-1. From linear extrapolation of the terminal part of the cell survival curve to zero drug dose, it appeared that about 1 in 10(5) (or 0.001%) of tumour cells were resistant to MeCCNU.

Induced and inherent resistance to alkylating agents in human small-cell bronchial carcinoma xenografts

Inherent and induced resistance was investigated in human small-cell lung cancer xenografts. Specimens from three patients were established in immune suppressed mice; the sensitivity of the xenografts to cyclophosphamide, MeCCNU and melphalan was determined using the growth delay end-point. Clinical chemosensitivity data were available in two cases and inherent differences in sensitivity were noted both in the xenografts and clinically. Radioactively labelled melphalan uptake studies were performed with these two xenografts. A number of different strategies to induce resistance were explored. Only one method proved to be successful and in only one of the xenografts; this was with cyclophosphamide. The induced resistant line was characterised in terms of the time course of its production, the degree of induced resistance, the growth rate, the cross-resistance pattern and stability of the phenotype; the possibility of altered antigenicity was also examined.

Randomized trial of chlorozotocin, neocarzinostatin, or methyl-CCNU in patients with malignant melanoma

One hundred twenty-two patients with disseminated malignant melanoma were randomized using an unbalanced randomization to receive chlorozotocin, neocarzinostatin, or MeCCNU. Of the 114 evaluable patients, 46 received chlorozotocin, 47 received neocarzinostatin, and 21 received MeCCNU. The response rates to these three drugs were 9%, 4%, and 14% respectively. Median survival times were 4.2, 3.4, and 5.8 months respectively. Toxicity was acceptable with all three agents. Chlorozotocin and neocarzinostatin do not appear to offer any improved response rates over MeCCNU for patients with disseminated malignant melanoma.

Studies on drug resistance in a human melanoma xenograft system

Alkylating agents and their functional analogues belong to the most useful antineoplastic drugs in the treatment of disseminated malignant melanoma. In conjunction with an open clinical phase II trial evaluating the combination of cisplatin and ifosfamide, 17 melanoma xenograft lines were established from patients often refractory to dacarbazine (DTIC). These xenograft lines were exposed to cisplatin, dacarbazine, dibromodulcitol, ifosfamide, methyl-CCNU, mitomycin C, and malonato-diaminocyclohexane-platinum II (PHM) at the respective LD 10/30 doses. Growth delay values less than 2 corresponded in 26/27 instances with progressive disease, whereas values greater than 2 corresponded in only 10/13 instances with achievement of a no-change status or a partial remission of the donor patient's disease. Among the panel of DNA-damaging agents tested, cross-resistance was incomplete. Some xenograft lines revealed unique chemosensitivity patterns in contrast to a uniform pattern of drug resistance in others (pleiotropic or multidrug resistance). The data confirm independently of results obtained in the phase II study that the combination of cisplatin and ifosfamide is effective against malignant melanoma refractory to dacarbazine. Suboptimal drug exposure, repeated up to 21 transplant generations, was employed to induce secondary resistance to either dacarbazine, melphalan or methyl-CCNU in a melanoma xenograft line originally quite sensitive to drug treatment. When the resistant sublines were exposed to the other agents, only partial cross-resistance was observed. Tumour volume responses to treatment with dacarbazine correlated with persisting DNA damage assayed 24 h after in vivo drug exposure in a sensitive line and the absence of such lesions in a resistant line.

cis-4-[[[(2-Chloroethyl)nitrosoamino]carbonyl]methylamino] cyclohexanecarboxylic acid, a nitrosourea with latent activity against an experimental solid tumor

cis-4-[[[(2-Chloroethyl)nitrosoamino]carbonyl]methylamino] cyclohexanecarboxylic acid (N-Me-cis-CCCNU) was synthesized in five steps from cis-4-aminocyclohexanecarboxylic acid via an N-tosylated intermediate. N-Me-cis-CCCNU, which is incapable of the facile decomposition that characterizes the clinically useful nitrosoureas, effected a significant cure rate of both early and established murine Lewis lung carcinoma, even though its in vitro half-life was approximately 5.5 times that of the unmethylated parent compound. This is the first observation of latent activity of a nitrosourea against an experimental solid tumor.

Therapeutic evaluation of five nitrosoureas in a human melanoma xenograft system

The development of nitrosoureas has switched from more lipophilic derivatives to congeners with higher water-solubility, since this property was presumably associated with a decrease in myelosuppression. We have compared the therapeutic efficacy of clinically well-known lipophilic nitrosoureas BCNU, CCNU, and MeCCNU with the recently introduced water-soluble nitrosoureas chlorozotocin (CZT) and hydroxyethyl-CNU (HeCNU), using a human melanoma xenograft system. There were considerable differences in tumor-inhibitory activity, with HeCNU ranking first and CZT last, and the rank order was similar for drug-induced lethality or bone marrow damage (in terms of reduced cellularity or macromolecular DNA damage). When the doses are expressed as percentages of the corresponding LD10/30 values, CZT ranks last and HeCNU low among conventional nitrosoureas. We conclude that water-solubility is not associated with reduced myelosuppression and that other guidelines will have to be adopted for rational development of nitrosoureas.

In vivo drug sensitivity assay of clonogenic human melanoma cells and correlation with treatment outcome

In vitro tests of tumor cell drug sensitivity have been suggested as a means of selecting more appropriate clinical strategies against human cancer and improving preclinical drug development. The lack of biotransformation in these in vitro assays precludes the meaningful assessment of several major chemotherapeutic agents, including dacarbazine and cyclophosphamide. In vivo drug exposure of tumor cells in agar diffusion chambers placed in mice offers a possible solution to problems of drug biotransformation and pharmacokinetics. We have prospectively used this system as an assay for sensitivity of clonogenic human melanoma cells. Tumor cells were tested fresh, cryopreserved, and/or cultured in vitro before or after clinical use of dacarbazine, semustine, and mitolactol in 41 patient-drug combinations in which a clinical correlation could be made. Tumor cell drug sensitivity in the assay using fresh or cryopreserved tumor cells was highly correlated with clinical response and resistance with clinical nonresponse. Cultured melanoma cells exhibited enhanced plating efficiency in comparison to both fresh and cryopreserved cells of the same tumor. Cultured cells also showed increased drug sensitivity which did not correlate with drug sensitivity of the same fresh or cryopreserved tumor or with clinical response. Tumor cell drug sensitivity assays carried out in vivo provide a possible basis for preclinical evaluation of drugs which are unsuitable for in vitro testing.

Ineffectiveness of chemotherapy in patients with metastatic ependymoma of the cauda equina

Six cases of intraspinal ependymoma metastasizing outside the central nervous system have been reported. This report documents a seventh case. This patient received multiple courses of combination and single-agent chemotherapy without evidence of tumor regression. All seven patients had four things in common: early onset of disease, numerous operations, massive local recurrence at the time distant metastases were noted, and a long time period from diagnosis to death.