NRG Oncology/RTOG1205: A Randomized Phase II Trial of Concurrent Bevacizumab and Reirradiation Versus Bevacizumab Alone as Treatment for Recurrent Glioblastoma

PURPOSE

To assess whether reirradiation (re-RT) and concurrent bevacizumab (BEV) improve overall survival (OS) and/or progression-free survival (PFS), compared with BEV alone in recurrent glioblastoma (GBM). The primary objective was OS, and secondary objectives included PFS, response rate, and treatment adverse events (AEs) including delayed CNS toxicities.

METHODS

NRG Oncology/RTOG1205 is a prospective, phase II, randomized trial of re-RT and BEV versus BEV alone. Stratification factors included age, resection, and Karnofsky performance status (KPS). Patients with recurrent GBM with imaging evidence of tumor progression ≥ 6 months from completion of prior chemo-RT were eligible. Patients were randomly assigned 1:1 to re-RT, 35 Gy in 10 fractions, with concurrent BEV IV 10 mg/kg once in every 2 weeks or BEV alone until progression.

RESULTS

From December 2012 to April 2016, 182 patients were randomly assigned, of whom 170 were eligible. Patient characteristics were well balanced between arms. The median follow-up for censored patients was 12.8 months. There was no improvement in OS for BEV + RT, hazard ratio, 0.98; 80% CI, 0.79 to 1.23; P = .46; the median survival time was 10.1 versus 9.7 months for BEV + RT versus BEV alone. The median PFS for BEV + RT was 7.1 versus 3.8 months for BEV, hazard ratio, 0.73; 95% CI, 0.53 to 1.0; P = .05. The 6-month PFS rate improved from 29.1% (95% CI, 19.1 to 39.1) for BEV to 54.3% (95% CI, 43.5 to 65.1) for BEV + RT, P = .001. Treatment was well tolerated. There were a 5% rate of acute grade 3+ treatment-related AEs and no delayed high-grade AEs. Most patients died of recurrent GBM.

CONCLUSION

To our knowledge, NRG Oncology/RTOG1205 is the first prospective, randomized multi-institutional study to evaluate the safety and efficacy of re-RT in recurrent GBM using modern RT techniques. Overall, re-RT was shown to be safe and well tolerated. BEV + RT demonstrated a clinically meaningful improvement in PFS, specifically the 6-month PFS rate but no difference in OS.

Behavioral and health outcomes from the NRG Oncology/NSABP B-36 trial comparing two different adjuvant therapy regimens for early-stage node-negative breast cancer

BACKGROUND

The NSABP B-36 compared four cycles of doxorubicin and cyclophosphamide (AC) with six cycles of 5-fluorouracil, epirubicin, and cyclophosphamide (FEC-100) in node-negative early-stage breast cancer. A sub-study within B-36, focusing on symptoms, quality of life (QOL), menstrual history (MH), and cardiac function (CF) was conducted.

PATIENTS AND METHODS

Patients completed the QOL questionnaire at baseline, during treatment, and every 6 months through 36 months. FACT-B Trial Outcome Index (TOI), symptom severity, and SF-36 Vitality and Physical Functioning (PF) scales scores were compared between the two groups using a mixed model for repeated measures analysis. MH was collected at baseline and subsequently assessed if menstrual bleeding occurred within 12 months prior to randomization. Post-chemotherapy amenorrhea outcome was examined at 18 months and was defined as lack of menses in the preceding year. Logistic regression was used to test for association of amenorrhea and treatment. CF assessment was done at baseline and 12 months. Correlation analysis was used to address associations between changes in baseline and 12-month PF and concurrent CF changes measured by LVEF.

RESULTS

FEC-100 patients had statistically significantly lower TOI scores during chemotherapy (P = 0.02) and at 6 months (P < 0.001); lower Vitality score at 6 months (P < 0.01), and lower PF score during the first year than AC patients. There were no statistically significant QOL score differences between the two groups beyond 12 months. No significant differences in symptom severity between the two groups were observed. Rates of amenorrhea were significantly different between FEC-100 and AC (67.4% vs. 59.1%, P < 0.001). There was no association between changes in LVEF and PF (P = 0.38).

CONCLUSIONS

Statistically significant QOL differences between the two groups favored AC; however, the magnitude was small and unlikely to be clinically meaningful. There was a clinical and statistically significant difference in risk for amenorrhea, favoring AC.

TRIAL REGISTRY

NCT00087178; Date of registration: 07/08/2004.

The Correlative Strength of Objective Physical Assessment Against the ECOG Performance Status Assessment in Individuals Diagnosed With Cancer

BACKGROUND

Individuals with cancer experience loss of function and disability due to disease and cancer-related treatments. Physical fitness and frailty influence treatment plans and may predict cancer outcomes. Outcome measures currently used may not provide sufficiently comprehensive assessment of physical performance.

OBJECTIVE

The objectives of this study are to: (1) describe the development of a functional measure, the Bellarmine Norton Assessment Tool (BNAT), for individuals with cancer; and (2) assess the relationship between the BNAT and the Eastern Cooperative Oncology Group (ECOG) Performance Status, a commonly used classification system by oncologists.

DESIGN

This was a prospective cohort correlation study.

METHODS

The BNAT encompasses 1 self-reported physical activity question and 4 objective tests: 2-Minute Step Test, 30-Second Sit to Stand, Timed Arm Curl, and Timed Up and Go. The BNAT score and its components were compared with ECOG Performance Status scores assigned by oncologists and analyzed for correlation and agreement.

RESULTS

A total of 103 male and female individuals (ages 33-87 years) with various cancer diagnoses participated. The mean (SD) ECOG Performance Status score was 0.95 (0.87), range 0 to 3, and the mean BNAT score was 14.9 (4.3), range 5 to 24. Spearman agreement association of BNAT and ECOG Performance Status scores revealed a significant moderate negative relationship (r = -0.568).

LIMITATIONS

The BNAT was compared with the ECOG Performance Status, a commonly used but subjective measure. Additionally, a common data set was used for both deriving and evaluating the BNAT performance scale.

CONCLUSIONS

There was a moderate negative linear relationship of BNAT to ECOG Performance Status scores across all participants. Utilization of the BNAT may reflect overall physical performance and provide comprehensive and meaningful detail to influence therapeutic decisions.

Multidisciplinary approach to low-dose CT screening for lung cancer in a metropolitan community

BACKGROUND

Lung cancer is the primary cause of cancer death in men and women in the USA, led by Kentucky. In 2015, the Centers for Medicare and Medicaid Services initiated annual lung cancer screening with a low-dose computed tomography (LDCT) scan. This observational cohort study evaluated the multidisciplinary approach to this screening in our metropolitan community.

METHODS

We present the prospective findings of patients who underwent a screening lung LDCT scan over a 2-year period at our institution in Kentucky. Patients who fulfilled the screening criteria were identified during an office visit with their primary care provider.

RESULTS

Of the 4170 patients who underwent a screening lung LDCT scan, a total of 838 (20.9%) patients had nodules >4 mm. Of the 70 patients diagnosed with lung cancer, Stage 1 non-small cell lung cancer was most commonly detected [38 cases (54.3%)]. A follow-up lung LDCT scan (n = 897), pulmonary function test (n = 157), positron emission tomography scan (n = 12) and a lung biopsy (n = 53) were performed for certain individuals who had anomalies observed on the screening lung LDCT scan. A total of 42% of patients enrolled in group tobacco cessation classes quit smoking.

CONCLUSIONS

This study provides a unique perspective of a lung LDCT scan screening program driven by primary care providers in a state plagued by cigarette smoking and lung cancer deaths and offers a valuable message into the prevention, high-risk screening and diagnosis of lung cancer.

ACTR-32. NRG ONCOLOGY RTOG 1205: RANDOMIZED PHASE II TRIAL OF CONCURRENT BEVACIZUMAB AND RE-IRRADIATION VS. BEVACIZUMAB ALONE AS TREATMENT FOR RECURRENT GLIOBLASTOMA

This study sought to determine whether re-irradiation (ReRT) and concurrent bevacizumab (BEV) improves overall survival (OS) compared to BEV alone in recurrent glioblastoma (GBM). Patients (pts) were randomized 1:1 to ReRT (35 Gy/10 fractions) plus BEV (IV 10 mg/kg q2 wks) vs. BEV alone. With 160 pts, there was 80% power to detect a 31% reduction in death hazard for BEV+RT at a one-sided significance level of 0.10 using a log rank test. OS and PFS were estimated by Kaplan-Meier and HRs estimated by exact binomial distribution. Objective response was assessed using MacDonald and RANO criteria. From 11/2012 to 4/2016, 182 pts were randomized, with 170 eligible, analyzable pts. 11 pts did not receive protocol treatment. Patient characteristics (age, KPS, re-resection rates) were balanced between arms. Median f/u for censored pts was 12.8 months (mos; min-max, 0.03–52.8). BEV+ReRT did not improve OS vs BEV alone, with median OS of 10.1 vs 9.7 mos, (HR=0.98, 95% CI=0.70–1.38, p=0.46). Median PFS for BEV+RT and BEV was 7.1 vs. 3.8 mos, respectively (HR=0.73, 95% CI=0.53–1.0, p=0.051). BEV+ReRT improved 6-mo PFS rate (PFS6): 54 vs. 29%, (HR=0.42, 95% CI=0.34–0.5, p=0.001). Overall, treatment was well tolerated: 5% acute and 0% delayed grade 3+ treatment-related AE. Most patients died from recurrent GBM. CONCLUSION: RTOG 1205 is the first, prospective, randomized multi-institutional study to evaluate the safety and efficacy of ReRT in recurrent GBM using modern RT techniques. Overall, ReRT was shown to be safe and well tolerated. BEV+ReRT did not demonstrate a benefit in OS but an improved PFS6, and clinically meaningful PFS improvement. Molecular correlates of response analyses are ongoing. Funded by U10CA180868, U10CA180822 from the National Cancer Institute.

Myelopreservation with the CDK4/6 inhibitor trilaciclib in patients with small-cell lung cancer receiving first-line chemotherapy: a phase Ib/randomized phase II trial

BACKGROUND

Chemotherapy-induced damage of hematopoietic stem and progenitor cells (HSPC) causes multi-lineage myelosuppression. Trilaciclib is an intravenous CDK4/6 inhibitor in development to proactively preserve HSPC and immune system function during chemotherapy (myelopreservation). Preclinically, trilaciclib transiently maintains HSPC in G1 arrest and protects them from chemotherapy damage, leading to faster hematopoietic recovery and enhanced antitumor immunity.

PATIENTS AND METHODS

This was a phase Ib (open-label, dose-finding) and phase II (randomized, double-blind placebo-controlled) study of the safety, efficacy and PK of trilaciclib in combination with etoposide/carboplatin (E/P) therapy for treatment-naive extensive-stage small-cell lung cancer patients. Patients received trilaciclib or placebo before E/P on days 1-3 of each cycle. Select end points were prespecified to assess the effect of trilaciclib on myelosuppression and antitumor efficacy.

RESULTS

A total of 122 patients were enrolled, with 19 patients in part 1 and 75 patients in part 2 receiving study drug. Improvements were seen with trilaciclib in neutrophil, RBC (red blood cell) and lymphocyte measures. Safety on trilaciclib+E/P was improved with fewer ≥G3 adverse events (AEs) in trilaciclib (50%) versus placebo (83.8%), primarily due to less hematological toxicity. No trilaciclib-related ≥G3 AEs occurred. Antitumor efficacy assessment for trilaciclib versus placebo, respectively, showed: ORR (66.7% versus 56.8%, P = 0.3831); median PFS [6.2 versus 5.0 m; hazard ratio (HR) 0.71; P = 0.1695]; and OS (10.9 versus 10.6 m; HR 0.87; P = 0.6107).

CONCLUSION

Trilaciclib demonstrated an improvement in the patient's tolerability of chemotherapy as shown by myelopreservation across multiple hematopoietic lineages resulting in fewer supportive care interventions and dose reductions, improved safety profile, and no detriment to antitumor efficacy. These data demonstrate strong proof-of-concept for trilaciclib's myelopreservation benefits.

CLINICAL TRAIL NUMBER

NCT02499770.

Identifying Health Information Technology Needs of Oncologists to Facilitate the Adoption of Genomic Medicine: Recommendations From the 2016 American Society of Clinical Oncology Omics and Precision Oncology Workshop

At the ASCO Data Standards and Interoperability Summit held in May 2016, it was unanimously decided that four areas of current oncology clinical practice have serious, unmet health information technology needs. The following areas of need were identified: 1) omics and precision oncology, 2) advancing interoperability, 3) patient engagement, and 4) value-based oncology. To begin to address these issues, ASCO convened two complementary workshops: the Omics and Precision Oncology Workshop in October 2016 and the Advancing Interoperability Workshop in December 2016. A common goal was to address the complexity, enormity, and rapidly changing nature of genomic information, which existing electronic health records are ill equipped to manage. The subject matter experts invited to the Omics and Precision Oncology Workgroup were tasked with the responsibility of determining a specific, limited need that could be addressed by a software application (app) in the short-term future, using currently available genomic knowledge bases. Hence, the scope of this workshop was to determine the basic functionality of one app that could serve as a test case for app development. The goal of the second workshop, described separately, was to identify the specifications for such an app. This approach was chosen both to facilitate the development of a useful app and to help ASCO and oncologists better understand the mechanics, difficulties, and gaps in genomic clinical decision support tool development. In this article, we discuss the key challenges and recommendations identified by the workshop participants. Our hope is to narrow the gap between the practicing oncologist and ongoing national efforts to provide precision oncology and value-based care to cancer patients.

Abstract P3-12-01: Impact of treatment on quality of life (QOL) and menstrual history (MH) in the NSABP B-36: A randomized phase III trial comparing six cycles of 5-fluorouracil (5-FU), epirubicin, and cyclophosphamide (FEC) to four cycles of adriamycin and cyclophosphamide

Background

NSABP B-36 compares 6 cycles of FEC-100 with 4 cycles of standard AC in pts with node-negative breast cancer. As reported separately, no significant differences between the two treatment arms were observed in the primary endpoint of disease-free survival or in the secondary endpoints of overall survival, recurrence-free, or distant recurrence-free intervals. Greater toxicity was reported in pts who received FEC compared to AC. We present here the results of the QOL and MH studies obtained prospectively in conjunction with the treatment study. We hypothesized that pts on FEC would experience greater treatment toxicity in the first 12 months of the study, and would have greater rates of amenorrhea at 18 months compared to pts on AC.

Methods

Among the 1,357 pts enrolled in the QOL study, 1,332 (675 AC, 657 FEC) submitted the baseline form and had QOL follow-up (fup) information. Pts completed: 1) the FACT-B instrument; 2) a symptom checklist; and 3) the SF-36 Vitality Scale, all at baseline, day 1 of cycle 4, and at 6, 12, 18, 24, 30, and 36 months after random assignment. FACT-B Trial Outcome Index (TOI), symptom severity, and vitality scores were compared between the two treatment arms using a mixed model for repeated measures analysis with adjustment for the baseline scores, type of surgery, and hormone receptor status, examining the first 12 months and the later time points separately. Menstrual status was collected at baseline for all enrolled pts, with subsequent assessments on day 1 of cycle 4, and at 6, 12, 18, 24, 30, and 36 months for pts with menstrual bleeding within 12 months prior to random assignment and not having had a hysterectomy and/or bilateral oophorectomy (1, 096 pts). Post-chemotherapy amenorrhea was defined as the lack of menstrual periods during the 12 months preceding the 18-month fup evaluation. Data from 921 pts (475 AC, 446 FEC) were available for analysis. Logistic regression, adjusted for type of surgery and hormone receptor status, was used to test for association of amenorrhea status and treatment.

Results

Both TOI and vitality scores were worse for pts on FEC compared to those on AC at 6 months (p&lt;0.01) with no significant difference at 12 months and beyond. No significant differences in symptom severity between the two treatment arms were observed. The rates of post-chemotherapy amenorrhea were significantly different between FEC and AC (66.8% vs. 58.7%, p=0.01) with positive hormone receptor status as an independent risk factor (p=0.03).

Conclusions

Women receiving FEC had diminished QOL at 6 months after random assignment, but no difference at 12 months or later. Premenopausal women receiving FEC experienced a higher rate of post-chemotherapy amenorrhea than women receiving AC.

Support

NCI grants U10-CA-12027, -37377, -69974, -69651 and -44066-26, and Pharmacia & Upjohn Company, a subsidiary of Pfizer, Inc.

Citation Format: Patricia A Ganz, John W Wilson, Hanna Bandos, André Robidoux, Alexander HG Paterson, Johnathan Polikoff, Luis Baez-Diaz, Adam M Brufsky, Louis Fehrenbacher, Aroop Mangalik, Patrick J Ward, Louise Provencher, John T Hamm, Philip J Stella, Robert L Carolla, Richard G Margolese, Henry R Shibata, Edith A Perez, Norman Wolmark. Impact of treatment on quality of life (QOL) and menstrual history (MH) in the NSABP B-36: A randomized phase III trial comparing six cycles of 5-fluorouracil (5-FU), epirubicin, and cyclophosphamide (FEC) to four cycles of adriamycin and cyclophosphamide [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P3-12-01.

Axitinib and/or bevacizumab with modified FOLFOX-6 as first-line therapy for metastatic colorectal cancer: a randomized phase 2 study

BACKGROUND

In this multicenter, open-label, randomized phase 2 trial, the authors evaluated the vascular endothelial growth factor receptor inhibitor axitinib, bevacizumab, or both in combination with chemotherapy as first-line treatment of metastatic colorectal cancer (mCRC).

METHODS

Patients with previously untreated mCRC were randomized 1:1:1 to receive continuous axitinib 5 mg twice daily, bevacizumab 5 mg/kg every 2 weeks, or axitinib 5 mg twice daily plus bevacizumab 2 mg/kg every 2 weeks, each in combination with modified 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX-6). The primary endpoint was the objective response rate (ORR).

RESULTS

In all, 126 patients were enrolled from August 2007 to September 2008. The ORR was numerically inferior in the axitinib arm (n = 42) versus the bevacizumab arm (n = 43; 28.6% vs 48.8%; 1-sided P = .97). Progression-free survival (PFS) (11.0 months vs 15.9 months; 1-sided P = .57) and overall survival (OS) (18.1 months vs 21.6 months; 1-sided P = .69) also were numerically inferior in the axitinib arm. Similarly, efficacy endpoints for the axitinib/bevacizumab arm (n = 41) were numerically inferior (ORR, 39%; PFS, 12.5 months; OS, 19.7 months). The patients who received axitinib had fewer treatment cycles compared with other arms. Common all-grade adverse events across all 3 treatment arms were fatigue, diarrhea, and nausea (all ≥49%). Hypertension and headache were more frequent in the patients who received axitinib. Patients in the bevacizumab arm had the longest treatment exposures and the highest rates of peripheral neuropathy.

CONCLUSIONS

Neither the addition of continuous axitinib nor the axitinib/bevacizumab combination to FOLFOX-6 improved ORR, PFS, or OS compared with bevacizumab as first-line treatment of mCRC.

A multicenter, phase I, dose-escalation study to assess the safety, tolerability, and pharmacokinetics of etirinotecan pegol in patients with refractory solid tumors

PURPOSE

This study was designed to establish the maximum tolerated dose (MTD) and to evaluate tolerability, pharmacokinetics, and antitumor activity of etirinotecan pegol.

EXPERIMENTAL DESIGN

Patients with refractory solid malignancies were enrolled and assigned to escalating-dose cohorts. Patients received 1 infusion of etirinotecan pegol weekly 3 times every 4 weeks (w × 3q4w), or every 14 days (q14d), or every 21 days (q21d), with MTD as the primary end point using a standard 3 + 3 design.

RESULTS

Seventy-six patients were entered onto 3 dosing schedules (58-245 mg/m(2)). The MTD was 115 mg/m(2) for the w × 3q4w schedule and 145 mg/m(2) for both the q14d and q21d schedules. Most adverse events related to study drug were gastrointestinal disorders and were more frequent at higher doses of etirinotecan pegol. Late onset diarrhea was observed in some patients, the frequency of which generally correlated with dose density. Cholinergic diarrhea commonly seen with irinotecan treatment did not occur in patients treated with etirinotecan pegol. Etirinotecan pegol administration resulted in sustained and controlled systemic exposure to SN-38, which had a mean half-life of approximately 50 days. Overall, the pharmacokinetics of etirinotecan pegol are predictable and do not require complex dosing adjustments. Confirmed partial responses were observed in 8 patients with breast, colon, lung (small and squamous cell), bladder, cervical, and neuroendocrine cancer.

CONCLUSION

Etirinotecan pegol showed substantial antitumor activity in patients with various solid tumors and a somewhat different safety profile compared with the irinotecan historical profile. The MTD recommended for phase II clinical trials is 145 mg/m(2) q14d or q21d.

Histological alterations in male A/J mice following nose-only exposure to tobacco smoke

The incidence and multiplicity of grossly observed and microscopic lesions of the respiratory tract of A/J mice exposed nose-only to mainstream smoke (50, 200, or 400 mg total particulate matter/m3 from 2R4F cigarettes) was compared to those of filtered air controls. Animals were necropsied at the end of exposure (5 mo) or following 4 or 7 mo of recovery. Lungs were visually inspected for tumors at all necropsies and examined histopathologically at 9 and 12 mo. At 5 mo no tumors were recorded. No significant elevations in tumor incidence or multiplicity were recorded although at 9 mo multiplicity was elevated in the mid-exposure group (0.90 versus 0.55 tumors per animal for controls). At 12 mo, multiplicity was increased over the 9-mo necropsy at all exposures except 200 mg/m3; however, there were no dose-related trends in multiplicity or incidence. Histopathological alterations included hyperplasia, metaplasia, and inflammation of the nose and larynx and proliferative lesions of the lungs. At 9 mo, the multiplicity of focal lung lesions was 1.4 per animal in controls but averaged 1.0 among smoke-exposed groups. There was an inverse relation (p < .059) between smoke concentration and the percentage of hyperplastic lesions at 9 mo. At 12 mo the high-exposure group had slightly increased multiplicity of 2.3 lesions compared with 1.6 among controls, while the percentage of hyperplasic lesions was similar between groups. Nose-only inhalation of mainstream tobacco smoke resulted in chronic inflammatory changes of the respiratory tract yet failed to produce statistically significant changes in tumor incidence or multiplicity.

Addition of bevacizumab to bolus fluorouracil and leucovorin in first-line metastatic colorectal cancer: results of a randomized phase II trial

PURPOSE

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, increases survival when combined with irinotecan-based chemotherapy in first-line treatment of metastatic colorectal cancer (CRC). This randomized, phase II trial compared bevacizumab plus fluorouracil and leucovorin (FU/LV) versus placebo plus FU/LV as first-line therapy in patients considered nonoptimal candidates for first-line irinotecan.

PATIENTS AND METHODS

Patients had metastatic CRC and one of the following characteristics: age > or = 65 years, Eastern Cooperative Oncology Group performance status 1 or 2, serum albumin < or = 3.5 g/dL, or prior abdominal/pelvic radiotherapy. Patients were randomly assigned to FU/LV/placebo (n = 105) or FU/LV/bevacizumab (n = 104). The primary end point was overall survival. Secondary end points were progression-free survival, response rate, response duration, and quality of life. Safety was also assessed.

RESULTS

Median survival was 16.6 months for the FU/LV/bevacizumab group and 12.9 months for the FU/LV/placebo group (hazard ratio, 0.79; P = .16). Median progression-free survival was 9.2 months (FU/LV/bevacizumab) and 5.5 months (FU/LV/placebo); hazard ratio was 0.50; P = .0002. Response rates were 26.0% (FU/LV/bevacizumab) and 15.2% (FU/LV/placebo) (P = .055); duration of response was 9.2 months (FU/LV/bevacizumab) and 6.8 months (FU/LV/placebo); hazard ratio was 0.42; P = .088. Grade 3 hypertension was more common with bevacizumab treatment (16% v 3%) but was controlled with oral medication and did not cause study drug discontinuation.

CONCLUSION

Addition of bevacizumab to FU/LV as first-line therapy in CRC patients who were not considered optimal candidates for first-line irinotecan treatment provided clinically significant patient benefit, including statistically significant improvement in progression-free survival.

Addition of bevacizumab to bolus fluorouracil and leucovorin in first-line metastatic colorectal cancer: results of a randomized phase II trial

PURPOSE

Bevacizumab, a monoclonal antibody against vascular endothelial growth factor, increases survival when combined with irinotecan-based chemotherapy in first-line treatment of metastatic colorectal cancer (CRC). This randomized, phase II trial compared bevacizumab plus fluorouracil and leucovorin (FU/LV) versus placebo plus FU/LV as first-line therapy in patients considered nonoptimal candidates for first-line irinotecan.

PATIENTS AND METHODS

Patients had metastatic CRC and one of the following characteristics: age > or = 65 years, Eastern Cooperative Oncology Group performance status 1 or 2, serum albumin < or = 3.5 g/dL, or prior abdominal/pelvic radiotherapy. Patients were randomly assigned to FU/LV/placebo (n = 105) or FU/LV/bevacizumab (n = 104). The primary end point was overall survival. Secondary end points were progression-free survival, response rate, response duration, and quality of life. Safety was also assessed.

RESULTS

Median survival was 16.6 months for the FU/LV/bevacizumab group and 12.9 months for the FU/LV/placebo group (hazard ratio, 0.79; P = .16). Median progression-free survival was 9.2 months (FU/LV/bevacizumab) and 5.5 months (FU/LV/placebo); hazard ratio was 0.50; P = .0002. Response rates were 26.0% (FU/LV/bevacizumab) and 15.2% (FU/LV/placebo) (P = .055); duration of response was 9.2 months (FU/LV/bevacizumab) and 6.8 months (FU/LV/placebo); hazard ratio was 0.42; P = .088. Grade 3 hypertension was more common with bevacizumab treatment (16% v 3%) but was controlled with oral medication and did not cause study drug discontinuation.

CONCLUSION

Addition of bevacizumab to FU/LV as first-line therapy in CRC patients who were not considered optimal candidates for first-line irinotecan treatment provided clinically significant patient benefit, including statistically significant improvement in progression-free survival.

A mixture of dioxins, furans, and non-ortho PCBs based upon consensus toxic equivalency factors produces dioxin-like reproductive effects

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD; dioxin) and related polyhalogenated aromatic hydrocarbons (PHAHs) alter the reproductive development of laboratory animals. Therefore, we exposed animals to a mixture of dioxins, furans, and polychlorinated biphenyls (PCBs) that included TCDD, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzofuran (1-PeCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), octachlorodibenzofuran (OCDF), 3,3',4,4'-tetrachlorobiphenyl (PCB77), 3,3',4,4',5-pentachlorobiphenyl (PCB126), and 3,3',4,4',5,5'-hexachlorobiphenyl (PCB169). The mixture composition approximated the relative abundance of these compounds in foodstuff (L. S. Birnbaum and M. J. DeVito, 1995, Toxicology Vol. 105, pp. 391-401). Following the work of Gray et al. with TCDD (1997, Toxicology and Applied Pharmacology Vol. 146, pp. 11-20), we exposed time-pregnant dams on gestation day (GD) 15 at doses up to 1.0 microgram TCDD toxic equivalency (TEQ)/kg and the development of offspring was monitored. This mixture significantly increased the time to puberty in both male and female offspring. At postnatal day (PND) 32 seminal vesicle weights were decreased; however, only ventral prostate weight was affected at PND 49 and no effects were seen at PND 63. In female offspring, the mixture caused dose-dependent increases in the incidence of vaginal thread. Ethoxyresorufin-O-deethylase (EROD) activity was higher than with TCDD the comparable TEQ exposure. Based on the slightly lowered responsiveness to the mixture, we used 2.0 microgram TEQ/kg to examine reproductive effects. This dose elicited the responses observed with 1.0 microgram TCDD/kg. Results indicate that the mixture causes a similar spectrum of effects seen with TCDD and the slightly lowered degree of response based on administered dose appears to be due to decreased transfer of mixture components to the offspring. Thus, the use of the WHO consensus TEFs (M. Van den Berg et al., 1998, Environ. Health Perspec. 106, 775-792) reasonably predicts the developmental toxicity of this mixture of dioxin-like PHAHs.

TCDD-mediated oxidative stress in male rat pups following perinatal exposure

2,3,7,8-tetrachlorododibenzo-p-dioxin (TCDD) is a highly persistent trace environmental contaminant and is one of the most potent toxicants known. Exposure to TCDD has been shown to cause oxidative stress in a variety of animal models. In this study, pregnant Long Evans rats were dosed with 1 microg TCDD/kg on gestational day (GD) 15 so as to investigate oxidative stress in the liver of male pups following gestational exposure to TCDD. Lipid peroxidation (TBARS), production of reactive oxygen species (ROS), and total glutathione (GSH) were assayed to identify changes in oxidative stress parameters in the pup liver at GD 21 and postnatal days (PND) 4, 25, 32, 49, and 63. Mean ROS levels in pups were elevated at all time points tested with a significant elevation at PND 4 and PND 25. However, pup hepatic lipid peroxidation was unchanged throughout the time course. In addition, hepatic total GSH levels were not significantly changed although the means for the TCDD-treated groups were less than those of the controls at all time points except PND 49. The results indicate that although the levels of ROS are increased following gestational/lactational exposure, this increase does not translate to direct oxidative damage or significant changes to endogenous antioxidant defense mechanisms. Further investigation into the effect of gestational/lactational exposure in pups should include additional endpoints for further characterization of the time course of the response, the effect upon extrahepatic tissues, and investigation of differences between male and female offspring.

Increasing uptake and bioactivation with development positively modulate diazinon toxicity in early life stage medaka (Oryzias latipes)

Diazinon, an organophosphate pesticide, becomes biotransformed to a more potent oxon metabolite that inhibits acetylcholinesterase (AChE). Early life stages (els) of medaka, Oryzias latipes, were used to determine how development of this teleost affects sensitivity to diazinon. With developmental progression, from day of fertilization to 7-day-old larvae, we found that the 96-h LC50 and AChE IC50 values decreased, indicating greater host sensitivity to diazinon upon continued development. We then examined changes in AChE activity, its inhibition by the active metabolite diazoxon, and uptake and bioactivation of the compound. AChE activity remained low during much of development but increased rapidly just prior to hatch. In addition, in vitro incubation of tissue homogenates from embryos or larvae showed no differences in the sensitivity of AChE to diazoxon. Uptake studies with 14C-diazinon revealed greater body burdens of 14C as medaka developed. In addition, AChE IC50 values determined by in vivo exposure to diazoxon were greater in larvae than in embryos. Because diazinon is bioactivated by the P450 enzyme system, two P450 inhibitors were used in vivo to explore the role of metabolism in sensitivity. When exposure to diazinon occurred in the presence of increasing amounts of piperonyl butoxide (PBO), AChE inhibition decreased in a dose-response fashion and 2.0 x 10(-5) M PBO alleviated any difference in inhibition between larvae and embryos. However, PBO did not alter total 14C uptake when exposed simultaneously with 14C-diazinon, nor did it affect AChE inhibition using diazoxon. Controls ruled out differential effects of PBO on uptake and inhibition. In addition, a second general P450 inhibitor, 1-aminobenzotriazole, also decreased AChE inhibition. Finally, using exogenous acetylcholinesterase as a trap for the oxon metabolite, larval microsomes displayed greater bioactivation of diazinon than did a microsomal preparation from embryos. Taken together, results suggest that uptake and bioactivation are working to enhance diazinon sensitivity in this developmental model of a teleost fish.

Disposition of polychlorinated dibenzo-p-dioxins, dibenzofurans, and non-ortho polychlorinated biphenyls in pregnant long evans rats and the transfer to offspring

Pharmacokinetic properties of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDFs), and non-ortho biphenyls (PCBs) play a critical role in their relative toxicity. The present study examined the transfer of these chemicals to offspring and placenta. Pregnant Long Evans rats received 0.0 (control), 0.05, 0.2, 0.8, and 1.0 microg/kg of dioxin toxic equivalence (TEQ) by oral gavage on the 15th gestational day (GD 15), using a dosing mixture that contained 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 1,2,3,7,8-pentachlorodibenzofuran (1-PeCDF), 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF), octachlorodibenzofuran (OCDF), 3,3',4,4'-tetrachlorobiphenyl (PCB 77), 3,3',4,4',5-pentachlorobiphenyl (PCB 126), and 3,3',4,4',5,5'-hexachlorobiphenyl (PCB 169) in ratios approximating that in food. Rats were euthanized on GD 16, GD 21, and postnatal day 4 (PND 4). The chemical concentrations in fetus, pup, placenta, and maternal liver, serum, and adipose tissue were determined using gas chromatography/high-resolution mass spectrometry. A dose-dependent increase in hepatic sequestration was seen with TCDD, PeCDD, 4-PeCDF, OCDF, PCB 126, and PCB 169, and the transfer to offspring was reduced at higher doses. 4-PeCDF, PeCDD and PCB 126 showed higher liver affinity than TCDD. TCDF, 1-PeCDF, and PCB 77 were metabolized rapidly. On GD 16, TCDD and the three PCBs reached equilibration between the fetus and placenta, but this did not occur with PeCDD and 4-PeCDF until GD 21, according to the lipid-based concentrations. Offspring compartments received more of the dosed compounds lactationally than transplacentally (7-28% versus 0.5-3%). The behavior of each congener was dose-dependent; therefore, extrapolation of high-dose experimental data should be used with caution.

Identification and characterization of a cDNA encoding cytochrome P450 3A from the fresh water teleost medaka (Oryzias latipes)

A new member of the CYP3A gene family has been cloned from the teleost fish medaka (Oryzias latipes) by reverse-transcriptase polymerase chain reaction (RT-PCR). Degenerate primers homologous to highly conserved regions of known CYP3A sequences were used for initial RT-PCRs. Individual PCR products were cloned, sequenced, and identified as those belonging to the cytochrome P450 superfamily based on amino acid sequence similarity and the presence of the highly conserved heme-binding region. PCR products were subsequently used as probes to screen a complementary DNA library. A full-length cDNA clone was identified containing a 1758-base-pair (bp) insert with an open reading frame encoding a single peptide of 500 amino acids. Comparisons of the deduced amino acid sequence to other known cytochrome P450 sequences indicate that this gene product is most similar to the CYP3A gene family and has been designated as CYP3A38 by the cytochrome P450 nomenclature committee. Northern blot analysis identified two abundant CYP3A related transcripts in liver of both male and female adults and demonstrated quantitative differences in abundance according to gender. Similarly, Western blot analysis demonstrated the presence of two abundant cytochrome P450 related proteins in liver of both male and female adults. These results suggests that O. latipes contains multiple forms of CYP3A. Heterologous expression of CYP3A38 cDNA in HEK 293 cells produced a single protein that was reactive with anti-scup P450A (CYP3A) polyclonal antibody. Microsomes of HEK 293 cells expressing recombinant CYP3A38 protein actively catalyzed the hydroxylation of testosterone.

In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin alters postnatal development of seminal vesicle epithelium

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been shown to alter male reproductive development of laboratory animals through in utero and lactational exposure. As a result of exposure, the accessory glands of the male reproductive tract, including the seminal vesicle, are decreased in size as determined by total weight of the tissue. Analysis of seminal vesicle weights over time suggests that the changes may be transient. Administration of 1.0 microg/kg TCDD during gestation caused a significant decrease in seminal vesicle weights of offspring 8-11 months of age. We examined the effects of TCDD on seminal vesicles from rats exposed in utero and lactationally. Pregnant Long Evans rats were gavaged on gestation day 15 with 1.0 microg/kg TCDD in corn oil. Male pups were euthanized and necropsied on postnatal days (PND) 15, 25, 32, 49, 63, and 120. Seminal vesicles were weighed and then fixed in 10% neutral buffered formalin and processed for microscopic examination. Seminal vesicle weights were not significantly decreased until PND 32. Androgen receptor mRNA expression in PND 25 seminal vesicles was not different from control. In the present study, TCDD exposure decreased seminal vesicle epithelial branching and differentiation. Control epithelial cells had tall columnar morphology with relatively abundant cytoplasm, whereas TCDD-treated cells had rounded nuclei and less cytoplasm. In addition, immunolocalization of proliferating nuclear antigen was confined to undifferentiated basal epithelial cells of controls but was found in both basal and luminal cells of the treated seminal vesicle. Results indicate that the TCDD-induced impaired growth of the rat seminal vesicles is associated with a dramatic decrease in the development of the epithelium.

The role of development and duration of exposure to the embryotoxicity of diazinon

Medaka, Oryzias latipes, were used as a laboratory surrogate for species of concern to define the effects of diazinon exposure on teleost embryogenesis. Medaka embryos were placed in a static, non-renewal system and exposures initiated on days 1, 3, or 5 of development. Following initiation of exposure, replicates (n=5) remained in diazinon for a total of 4 days or from the day of initiation to day 9 of development. This exposure scenario was designed to elucidate sensitive periods in development for diazinon-induced toxicity but also shows the effect of added exposure duration on the degree of toxicity. Embryos were observed daily and endpoints recorded included: edema formation, total hatch, mean day of hatch, percentage of larvae with swim bladder inflation, and total length of larvae on day 14, when observations were terminated. Diazinon exposure resulted in decreases in hatch success, swim bladder inflation and the total length of larvae. In addition, dose-response increases in the incidence of edemas of the pericardial sac and vitelline veins were recorded. As expected, severity of embryotoxicity was positively correlated with duration of exposure. While no developmental period was the most sensitive for all toxic effects, for certain endpoints the severity of effects was dependent on exposure timing. Total hatch was greatly affected in embryos exposed from day 1 until day 5 whereas edema was more prevalent in embryos exposed later in development. Finally, among endpoints recorded, total length of larvae was the most sensitive indicator of exposure with all exposure groups showing significant (P<0.05) decreases in length at 5 ppm.

Thiobencarb-induced embryotoxicity in medaka (Oryzias latipes): stage-specific toxicity and the protective role of chorion

Thiobencarb (S-(4-chlorobenzyl)-N,N-diethyl thiol carbamate) has been one of the herbicides previously associated with fish kills in agricultural drains near the Sacramento/San Joaquin rivers and their Delta. This area is an important spawning ground for fish, and thus there are concerns over possible toxic effects on early life stages of fishes. To define targets of thiobencarb embryotoxicity and to determine the degree of protection afforded by the chorion, medaka (Oryzias latipes) embryos were exposed under static nonrenewal conditions. Responses to exposures initiated at blastula or at initiation of heart beat (stages 10 and 23, respectively) were assessed. In addition, enzymatically dechorionated embryos (stage 13, gastrula) were exposed and compared to responses in embryos with intact chorions. Embryos were observed daily for development and for gross abnormalities including: bradycardia, pericardial edema, hemostasis, poor yolk resorption, cephalic and spinal deformities, and abnormal hatching. A subset was also evaluated for histologic alterations. Based on gross abnormalities, the concentration of thiobencarb affecting 50% (EC(50)) of embryos exposed at blastula was 3.6 mg/l, while the putative no observable effect concentration (NOEC) was 1.0 mg/l. For embryos exposed at onset of heart beat (stage 23), these values were 4.1 and 2.5 mg/l, respectively. Dechorionated embryos tended to be more sensitive than their chorionated cohorts (LC(50)=2.5 vs. 1.0 mg/l). Liver histologic alterations were seen in chorionated embryos at EC(50) levels and higher. Stage-specific toxicity was evident; nevertheless, the EC(50) and NOEC values for embryos treated at stage 10 and stage 23 were similar.

Further evaluation of intensified and increased total dose of cyclophosphamide for the treatment of primary breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-25

PURPOSE

In 1989, the National Surgical Adjuvant Breast and Bowel Project initiated the B-22 trial to determine whether intensifying or intensifying and increasing the total dose of cyclophosphamide in a doxorubicin-cyclophosphamide combination would benefit women with primary breast cancer and positive axillary nodes. B-25 was initiated to determine whether further intensifying and increasing the cyclophosphamide dose would yield more favorable results.

PATIENTS AND METHODS

Patients (n = 2,548) were randomly assigned to three groups. The dose and intensity of doxorubicin were similar in all groups. Group 1 received four courses, ie, double the dose and intensity of cyclophosphamide given in the B-22 standard therapy group; group 2 received the same dose of cyclophosphamide as in group 1, administered in two courses (intensified); group 3 received double the dose of cyclophosphamide (intensified and increased) given in group 1. All patients received recombinant human granulocyte colony-stimulating factor. Life-table estimates were used to determine disease-free survival (DFS) and overall survival.

RESULTS

No significant difference was observed in DFS (P =.20), distant DFS (P =.31), or survival (P =.76) among the three groups. At 5 years, the DFS in groups 1 and 2 (61% v 64%, respectively; P =. 29) was similar to but slightly lower than that in group 3 (61% v 66%, respectively; P = 08). Survival in group 1 was concordant with that in groups 2 (78% v 77%, respectively; P =.71) and 3 (78% v 79%, respectively; P =.86). Grade 4 toxicity was 20%, 34%, and 49% in groups 1, 2, and 3, respectively. Severe infection and septic episodes increased in group 3. The decrease in the amount and intensity of cyclophosphamide and delays in therapy were greatest in courses 3 and 4 in group 3. The incidence of acute myeloid leukemia increased in all groups.

CONCLUSION

Because intensifying and increasing cyclophosphamide two or four times that given in standard clinical practice did not substantively improve outcome, such therapy should be reserved for the clinical trial setting.

Alterations in physiological parameters of rainbow trout (Oncorhynchus mykiss) with exposure to copper and copper/zinc mixtures

Rainbow trout (Oncorhynchus mykiss) were exposed to sublethal concentrations of copper (Cu, 14 microgram/liter) and zinc (Zn, 57 and 81 microgram/liter) for a 21-day period. The four treatments included a control, a Cu control, a Cu and low-Zn treatment and a Cu and high-Zn treatment. Selected parameters [e.g., hemoglobin (Hb), hematocrit (Hct), plasma glucose, lactate and cortisol, differential leukocyte count, respiratory burst, tissue metal concentrations, hepatic metallothionein (MT), brain acetylcholinesterase (AChE)] were evaluated at 2, 7, 14, and 21 days of exposure. Whole blood and plasma parameters were not altered by exposure to metals. The percentage of lymphocytes was consistently decreased in the three metal treatments, while percentages of neutrophils and monocytes were increased. Respiratory burst activity was elevated in all metal treatments. Gill Zn concentration was highly variable, with no significant alterations occurring. Gill Cu concentration was elevated above control levels in all metal treatments. Gill Cu concentration in the two Cu/Zn treatments was also elevated above levels in the Cu control. Hepatic metal concentrations and MT levels were not altered from control values. Measurements of brain AChE indicated an elevation in this parameter across metal treatments. In general, alterations in physiological parameters appeared to be due to Cu, with Zn having no interactive effect.

Methoxyresorufin: an inappropriate substrate for CYP1A2 in the mouse

Hepatic microsomes derived from Cypla2(-/-) knockout (KO) and parental strains of mice, C57BL/6N and 129Sv, were used to examine the specificity of methoxyresorufin and acetanilide as substrates for CYP1A2 activity. In addition, animals from each group were exposed to CYP1-inducing compounds. As expected, microsomes from untreated 1a2 KO mice did not have immunodetectable CYP1A2 protein; however, methoxyresorufin-O-demethylase (MROD, 25.5+/-6.1 pmol/min/mg protein) and acetanilide-4-hydroxylation (ACOH, 0.64+/-0.04 nmol/min/mg protein) activities were still present. Furthermore, induction of ethoxyresorufin-O-deethylase (EROD) by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in 1a2 KO mice was accompanied by a greater than 70-fold increase in MROD activity. In contrast, ACOH was only induced 2-fold by TCDD. As with 1a2 KO mice, the parental strains exposed to TCDD or 2,3,4,7,8-pentachlorodibenzofuran (4-PeCDF) showed substantial EROD and MROD induction, whereas ACOH activity was induced to a lesser degree. PCB153 (2,2',4,4',5,5'-hexachlorobiphenyl) resulted in low levels of both EROD and MROD induction. Results indicate that both substrates are subject to metabolism by non-CYP1A2 sources, and the apparent contribution of CYP1A1 activity to methoxyresorufin metabolism makes MROD unsuitable for differentiating CYP1A1 and CYP1A2 activities in the mouse.

Organophosphate-induced acetylcholinesterase inhibition and embryonic retinal cell necrosis in vivo in the teleost (Oryzias latipes)

Recent monitoring of the Sacramento-San Joaquin River system (CA) indicates that levels of the organophosphate pesticide, diazinon, exceed National Academy of Science guidelines and these levels result in toxicity in USEPA acute toxicity tests with Ceriodaphnia dubia. Since organophosphates (OPs) inhibit acetylcholinesterase (AChE), the present study examined the effects of diazinon on the embryonic nervous system of a model teleost, medaka, Oryzias latipes. Preliminary histological screens revealed limited retinal cell necrosis in control embryos with apparent increased necrosis in diazinon-exposed embryos. Subsequently, embryos were exposed to 1.8 x 10(-5), 4.4 x 10(-5), or to 8.8 x 10(-5) M diazinon and replicates were frozen for biochemical analysis or were fixed for histopathological analysis at days 3, 5, and 7 of development. Diazinon exposure significantly inhibited AChE activity within whole embryos and in homogenates of retinas from treated animals. Histological examination of embryos indicated that as the retina underwent differentiation into distinct cell layers, between days 5 and 7, small foci of necrotic cells became apparent within the inner nuclear layer and isolated individual pyknotic cells were observed in the ganglion layer. Quantification of foci of necrotic cells revealed that 8.8 x 10(-5) M diazinon increased number and area of these lesions. Enzyme histochemistry localized AChE activity to regions equivalent to sites of necrosis. Separate exposures of embryos to the OP, diisopropylphosphorofluoridate, produced large foci of necrotic cells at sites equivalent to those seen following diazinon exposure.

Phase I and II studies of toremifene

Toremifene (Fareston) is a triphenylethylene derivative structurally similar to tamoxifen (Nolvadex) that was selected for development based on its in vitro activity against breast cancer and its lesser uterotrophic effect than tamoxifen in rat models. In phase I and II studies conducted in several countries, toremifene was well tolerated over a wide range of doses (10 to 680 mg/d). The major side effects were hot flashes, nausea, and vomiting. Toremifene's excretion half-life is 5 days. It produces a modest decline in serum levels of luteinizing hormone, follicle-stimulating hormone, and antithrombin III, as well as an increase in sex hormone-binding globulin levels. In studies in which toremifene was used as first-line therapy in patients with estrogen receptor (ER)-positive or ER-unknown tumors, response rates to doses of 40 to 60 mg/day ranged from 30% to 54%. In two larger studies of patients who had proved refractory to tamoxifen therapy, toremifene produced an objective response rate of 4% to 5%. When patients with stable disease were added to those with objective responses, 27% to 28% of patients were considered to derive clinical benefit from toremifene. The dose range chosen for further study was 40 to 60 mg/d.

The efficacy of recombinant human granulocyte colony-stimulating factor and recombinant human granulocyte macrophage colony-stimulating factor in permitting the administration of higher doses of cyclophosphamide in a doxorubicin-cyclophosphamide combination. An NSABP pilot study in patients with metastatic or high-risk primary breast cancer. National Surgical Adjuvant Breast and Bowel Project

Colony-stimulating factors (CSFs) shorten the duration of myelosuppression following chemotherapy and, thus, allow the administration of higher doses. This study evaluates the efficacy of granulocyte macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) in allowing administration of high-dose cyclophosphamide in combination with doxorubicin. Ninety women with metastatic, locally advanced, or high-risk (> or = 10 positive nodes) breast cancer and no prior anthracycline treatment were given doxorubicin (60 mg/m2) with progressively increased doses of cyclophosphamide (1,200 mg/m2, 1,800 mg/m2, and 2,400 mg/m2). The first 60 patients received GM-CSF; the remaining 30, G-CSF. The maximum tolerated dose was not reached with 2,400 mg/m2 of cyclophosphamide. When compared to GM-CSF, G-CSF significantly reduced the duration of granulocytopenia (P < .001). No differences in duration of thrombocytopenia were noted. The results were not sufficiently consistent to indicate a trend toward reduction in rates of febrile neutropenia with one CSF versus the other. However, patients who received G-CSF were hospitalized less frequently than those receiving GM-CSF. With CSFs, high-dose cyclophosphamide in combination with doxorubicin can be safely administered on an outpatient basis. A shorter duration of granulocytopenia resulted from the use of G-CSF than from GM-CSF.

Inefficacy of low-dose continuous oral etoposide in non-small cell lung cancer

Etoposide is more active in small cell lung cancer when given over 5 days than as a single injection. To examine this concept further, we designed this Phase II study in NSCLC using continuous low-dose oral etoposide. We enrolled 19 patients with measurable disease and the standard eligibility criteria. 16 had no prior chemotherapy. Etoposide was given at a dose of 50 mg by mouth daily. The median duration of therapy was 63 days (14-212 days). Toxicity was mild myelosuppression and GI symptoms. Therapy was discontinued because of progression of disease in 13 patients, toxicity (GI) in 3 patients; intercurrent disease, self-removal, and other reasons in 1 patient each. No complete or partial responses were seen (95% CI: 0-17.6%). The median survival after entry into the trial was 159 days (41-571+ days). We conclude that low-dose continuous oral etoposide is a well-tolerated but ineffective regimen in non-small cell lung cancer.

Long-term intravenous hydroxyurea infusions in patients with advanced cancer. A phase I trial

BACKGROUND

Hydroxyurea is an S-phase specific drug. Constant exposure of tumor cells with a low S-phase fraction to the agent may result in improved cell kill. Because of its short half-life, a continuous intravenous infusion may result in better tumor exposure than intake by mouth. The goal of this trial was to find the longest tolerable duration of a continued intravenous infusion of hydroxyurea (HU) given at escalating doses.

METHODS

Eligible patients had histologically confirmed cancer without effective alternate therapy, normal blood counts, liver and kidney function. After giving informed consent, the infusion began via a permanent indwelling catheter utilizing a portable pump. Dose levels (in g/m2/d) were 0.5 for level I, 1.0 for level II, 1.66 for level III, and 2.5 for level IV.

RESULTS

Fourteen patients were entered. Five were men. Median age was 56 years of age (range: 32-67), median performance status 1 (range: 0-2). Diagnoses were as follows: colorectal cancer, seven; unknown primary site, three; breast cancer, two; melanoma, one; and adenoid-cystic carcinoma, one. Nine patients were pretreated with chemotherapy. Three patients were entered per dose level, except on level I, were five were entered. The mean duration of infusion was 12 weeks on level I, 5 weeks on II, 3 on III, 1 on IV. Toxicity included leukopenia below 2.0 K/mm3 in one patient each on levels III and IV, thrombocytopenia below 100 K/mm3 in one patient each on levels II and IV, and stomatitis in three patients (one on level II and two on IV). This toxicity was dose limiting. One patient on level III, with an unknown primary, had an objective response. HU levels were measured by a modification of the Fabricius-Rajewsky method. Mean plasma levels in micrograms per milliliter (SEM) were as follows: level I, 3.6 (0.23); level II, 5.1 (0.57); level III, 10.1 (1.55); and level IV, 16.7 (one point). Fetal hemoglobin rose two-fold and five-fold in two patients on level I after 9 and 16 weeks on therapy, respectively.

CONCLUSIONS

HU as a continuous intravenous infusion is well tolerated; the maximum duration of therapy is related inversely with the dose given. No major antitumor activity was seen. The greatest interest in the drug rests in its future use as a modulator and radiation potentiator. The increase in hemoglobin F was of interest and may be important in the treatment of sickle cell disease.

Phase I Study of Toremifene in Patients With Advanced Cancer

In the report entitled "Phase I Study of Toremifene in Patients With Advanced Cancer" by Hamm et al (J Clin Oncol 9:2036–2041, 1991), the chemical structure "R''' " for toremifene, N-desmethyltoremifene, and 4-hydroxytoremifene should have been "R''' = CL," and the following report should have been referenced: Kohler PC, Hamm JT, Wiebe VJ, et al: Phase I study of the tolerance and pharmacokinetics of toremifene in patients with cancer. Breast Cancer Res Treat 16:19-26, 1990

Phase I study of toremifene in patients with advanced cancer

A phase I multicenter evaluation of a novel antiestrogen, toremifene, was undertaken in postmenopausal women with various advanced difficult-to-treat malignancies. One hundred and seven women were treated at one of six dosage levels (10, 20, 40, 60, 200, or 400 mg/d orally) for at least 8 weeks. Weekly evaluations for toxicity were conducted. The most common side effects were nausea (31%), vomiting (12%), and hot flashes (29%). Five patients were removed from the study for possible adverse reactions: three patients experienced hypercalcemia; one experienced tremulousness, fatigue, and inability to think clearly; and one had vaginal bleeding. Twelve patients died while on study, 11 with disease progression and one with a pulmonary embolus. Sex hormone-binding globulin (SHBG) levels increased and there was a modest decline in serum antithrombin III levels. Four of 48 assessable patients had partial responses: three with breast cancer and one with endometrial cancer. Toremifene was generally well tolerated at the doses tested.

New hormonal approaches to the treatment of breast cancer

From this data we can draw several conclusions. Although many new hormonal agents have been developed, there has not been significant improvement in tumor response to single agents over the past several decades. By applying knowledge of tumor ER and PR patient populations can be selected which will have a higher response rate to a given hormonal agent. The approach of combining chemotherapy and hormonal therapy does not appear to significantly alter the course of the disease. Sequential use of Tamoxifen, Premarin, and chemotherapy has been shown in cell lines and animal models to synchronize cells thus increasing the efficacy of chemotherapy. Clinical trials of this synchronization generally show higher response rates including significantly higher CR rates than chemotherapy alone. This approach appears promising and is undergoing further trials. LHRH agonists and tamoxifen are effective in premenopausal women with receptor positive tumors and may replace surgical ablative therapy. Aminoglutethimide is gaining wider acceptance as second-line therapy in postmenopausal ER-positive patients. The new agent 4-OHA may be as effective as AG but with fewer side effects. Toremifine a new antiestrogen and RU486 a new antiprogesterone are undergoing trials. While these new agents appear promising with fewer side effects or greater specificity of action, with the exception of sequential hormone priming/chemotherapy they represent 'the same old approach'. By this we mean manipulation of the hormonal environment of the cell in a continuous fashion acting via the estrogen receptor mechanism to achieve tumor regression. While certain new agents may be more tolerable, it is unlikely that a 'break through' will occur with this approach. The problem is the emergence of cells resistant to hormonal therapy. This occurs either through proliferation of a preexisting resistant clone or development under selective pressure of resistant tumors. Some but not all of these resistant clones have escaped by virtue of not having estrogen receptor present. Others have defects further along the action cascade of estrogen stimulation, such as a defective receptor which cannot bind effectively to the nuclear acceptor sites, or lacking certain other growth factors such as TGF-beta. Whatever the deficit, most patients eventually develop resistant tumors. It is in this direction, toward manipulating later points in the estrogen cascade which our attention should turn to achieve more effective hormonal therapy.

Phase I study of the tolerance and pharmacokinetics of toremifene in patients with cancer

Toremifene is a triphenylethylene derivative structurally and pharmacologically similar to tamoxifen. This Phase I trial assessed the safety, pharmacokinetics, anti-estrogenic, and estrogenic effects of toremifene at six dose levels (10, 20, 40, 60, 200, and 400 mg/day). The most common side-effects associated with therapy included gastrointestinal (nausea/vomiting 43%), anti-estrogenic (hot flashes 29%), and CNS (dizziness/vertigo 12%). Three patients with bone metastases from breast cancer developed hypercalcemia. At doses greater than or equal to 40 mg/day a decline in LH and FSH occurred which was not statistically significant. At all doses tested SHBG rose during therapy. A dose dependent estrogenic blockade was seen on the vaginal epithelium following challenge with transdermal estradiol. Steady-state concentrations of toremifene were reached within 4 weeks, and at doses greater than or equal to 60 mg/day ranged from 879-3445 ng/ml. The half-life was found to be 5 days, and at three weeks following discontinuation of treatment concentrations greater than 24 ng/ml were detected. The N-desmethyl and 4-hydroxy metabolites achieved steady state levels within 4 weeks and had half-lives of 6 and 5 days respectively. Partial responses were seen in 4 patients, 3 with breast cancer treated at 200 mg/day and 1 with endometrial cancer treated at 400 mg/day.

A phase II trial of vinblastine, bleomycin, and cisplatin induction followed by dacarbazine and dibromodulcitol maintenance in the treatment of metastatic melanoma. A follow-up study of twenty-two patients

Twenty-two patients with metastatic melanoma were treated with a chemotherapy regimen consisting of two cycles of induction therapy with vinblastine, bleomycin, and cisplatin, followed by maintenance therapy with dacarbazine and dibromodulcitol. A 17% response rate was noted in this patient group, with a median survival of 40 weeks. Objective responses were limited to cutaneous, nodal, pulmonary, and one adrenal site of metastatic disease. Toxicity was acceptable and was limited to myelosuppression and nausea with emesis. Further study appears warranted to define the optimal treatment plan for metastatic melanoma.

A phase II trial of chlorambucil in non-small cell lung cancer

A Phase II trial of high-dose chlorambucil at 108 mg/m2 was undertaken in non-small cell lung cancer. No complete or partial objective responses were observed, and significant toxicity, including nausea, vomiting, and seizures, was noted. Chlorambucil at this dose and schedule of administration is not recommended for the treatment of non-small cell lung cancer.