Challenges in oncology career: are we closing the gender gap? Results of the new ESMO Women for Oncology Committee survey

BACKGROUND

Following a European Society for Medical Oncology Women for Oncology (ESMO W4O) survey in 2016 showing severe under-representation of female oncologists in leadership roles, ESMO launched a series of initiatives to address obstacles to gender equity. A follow-up survey in October 2021 investigated progress achieved.

MATERIALS AND METHODS

The W4O questionnaire 2021 expanded on the 2016 survey, with additional questions on the impact of ethnicity, sexual orientation and religion on career development. Results were analysed according to respondent gender and age.

RESULTS

The survey sample was larger than in 2016 (n = 1473 versus 482), especially among men. Significantly fewer respondents had managerial or leadership roles than in 2016 (31.8% versus 51.7%). Lack of leadership development for women and unconscious bias were considered more important in 2021 than in 2016. In 2021, more people reported harassment in the workplace than in 2016 (50.3% versus 41.0%). In 2021, ethnicity, sexual orientation and religion were considered to have little or no impact on professional career opportunities, salary setting or related potential pay gap. However, gender had a significant or major impact on career development (25.5% of respondents), especially in respondents ≤40 years of age and women. As in 2016, highest ranked initiatives to foster workplace equity were promotion of work-life balance, development and leadership training and flexible working. Significantly more 2021 respondents (mainly women) supported the need for culture and gender equity education at work than in 2016.

CONCLUSIONS

Gender remains a major barrier to career progression in oncology and, although some obstacles may have been reduced since 2016, we are a long way from closing the gender gap. Increased reporting of discrimination and inappropriate behaviour in the workplace is a major, priority concern. The W4O 2021 survey findings provide new evidence and highlight the areas for future ESMO interventions to support equity and diversity in oncology career development.

Validation of a multi-ancestry polygenic risk score and age-specific risks of prostate cancer: A meta-analysis within diverse populations

Background

We recently developed a multi-ancestry polygenic risk score (PRS) that effectively stratifies prostate cancer risk across populations. In this study, we validated the performance of the PRS in the multi-ancestry Million Veteran Program and additional independent studies.

Methods

Within each ancestry population, the association of PRS with prostate cancer risk was evaluated separately in each case-control study and then combined in a fixed-effects inverse-variance-weighted meta-analysis. We further assessed the effect modification by age and estimated the age-specific absolute risk of prostate cancer for each ancestry population.

Results

The PRS was evaluated in 31,925 cases and 490,507 controls, including men from European (22,049 cases, 414,249 controls), African (8794 cases, 55,657 controls), and Hispanic (1082 cases, 20,601 controls) populations. Comparing men in the top decile (90-100% of the PRS) to the average 40-60% PRS category, the prostate cancer odds ratio (OR) was 3.8-fold in European ancestry men (95% CI = 3.62-3.96), 2.8-fold in African ancestry men (95% CI = 2.59-3.03), and 3.2-fold in Hispanic men (95% CI = 2.64-3.92). The PRS did not discriminate risk of aggressive versus nonaggressive prostate cancer. However, the OR diminished with advancing age (European ancestry men in the top decile: ≤55 years, OR = 7.11; 55-60 years, OR = 4.26; >70 years, OR = 2.79). Men in the top PRS decile reached 5% absolute prostate cancer risk ~10 years younger than men in the 40-60% PRS category.

Conclusions

Our findings validate the multi-ancestry PRS as an effective prostate cancer risk stratification tool across populations. A clinical study of PRS is warranted to determine whether the PRS could be used for risk-stratified screening and early detection.

Funding

This work was supported by the National Cancer Institute at the National Institutes of Health (grant numbers U19 CA214253 to C.A.H., U01 CA257328 to C.A.H., U19 CA148537 to C.A.H., R01 CA165862 to C.A.H., K99 CA246063 to B.F.D, and T32CA229110 to F.C), the Prostate Cancer Foundation (grants 21YOUN11 to B.F.D. and 20CHAS03 to C.A.H.), the Achievement Rewards for College Scientists Foundation Los Angeles Founder Chapter to B.F.D, and the Million Veteran Program-MVP017. This research has been conducted using the UK Biobank Resource under application number 42195. This research is based on data from the Million Veteran Program, Office of Research and Development, and the Veterans Health Administration. This publication does not represent the views of the Department of Veteran Affairs or the United States Government.

A Rare Germline HOXB13 Variant Contributes to Risk of Prostate Cancer in Men of African Ancestry

A rare African ancestry-specific germline deletion variant in HOXB13 (X285K, rs77179853) was recently reported in Martinican men with early-onset prostate cancer. Given the role of HOXB13 germline variation in prostate cancer, we investigated the association between HOXB13 X285K and prostate cancer risk in a large sample of 22 361 African ancestry men, including 11 688 prostate cancer cases. The risk allele was present only in men of West African ancestry, with an allele frequency in men that ranged from 0.40% in Ghana and 0.31% in Nigeria to 0% in Uganda and South Africa, with a range of frequencies in men with admixed African ancestry from North America and Europe (0-0.26%). HOXB13 X285K was associated with 2.4-fold increased odds of prostate cancer (95% confidence interval [CI] = 1.5-3.9, p = 2 × 10^-4), with greater risk observed for more aggressive and advanced disease (Gleason ≥8: odds ratio [OR] = 4.7, 95% CI = 2.3-9.5, p = 2 × 10^-5; stage T3/T4: OR = 4.5, 95% CI = 2.0-10.0, p = 2 × 10^-4; metastatic disease: OR = 5.1, 95% CI = 1.9-13.7, p = 0.001). We estimated that the allele arose in West Africa 1500-4600 yr ago. Further analysis is needed to understand how the HOXB13 X285K variant impacts the HOXB13 protein and function in the prostate. Understanding who carries this mutation may inform prostate cancer screening in men of West African ancestry. PATIENT SUMMARY: A rare African ancestry-specific germline deletion in HOXB13, found only in men of West African ancestry, was reported to be associated with an increased risk of overall and advanced prostate cancer. Understanding who carries this mutation may help inform screening for prostate cancer in men of West African ancestry.

Effect of HIV infection on TB treatment outcomes and time to mortality in two urban hospitals in Ghana-a retrospective cohort study

Introduction

Tuberculosis (TB) is currently causing more deaths than Human Immunodeficiency Virus (HIV) globally. Ghana as one of the 30 high burden TB/HIV countries has a high annual TB case-fatality rate of 10%. The study sought to assess the effect of HIV infection on TB treatment outcomes and assess the time to mortality after treatment onset.

Methods

We conducted a review of treatment files of TB patients who were treated from January 2013 to December 2015 in two urban hospitals in the Accra Metropolis. Modified Poisson regression analysis was used to measure the association between HIV infection and TB treatment outcomes. Kaplan-Meier survival estimates were used to plot survival curves.

Results

Seventy-seven percent (83/107) of HIV infected individuals had successful treatment, compared to 91.2% (382/419) treatment success among HIV non-infected individuals. The proportion of HIV-positive individuals who died was 21.5% (23/107) whilst that of HIV-negative individuals was 5.5% (23/419). Being HIV-positive increased the risk of adverse outcome relative to successful outcome by a factor of 2.89(95% CI 1.76-4.74). The total number of deaths recorded within the treatment period was 46; of which 29(63%) occurred within the first two months of TB treatment. The highest mortality rate observed was among HIV infected persons (38.6/1000 person months). Of the 107 TB/HIV co-infected patients, 4(3.7%) initiated ART during TB treatment.

Conclusion

The uptake of ART in co-infected individuals in this study was very low. Measures should be put in place to improve ART coverage among persons with TB/HIV co-infection to help reduce mortality.

Abstract P5-04-04: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Das GM, Kulkarni S, Oturkar C, Edge SB, Wilton JH, Wang J, Swetzig WM, Adjei AA, Bies R, Hutson AD, Morrison CD, Kaipparettu BA, Groman A, Kumar S, Capuccino H. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-04-04.

Detection of Human Papillomavirus Genotypes and Epstein-Barr Virus in Nasopharyngeal Carcinomas at the Korle-Bu Teaching Hospital, Ghana

Nasopharyngeal carcinomas (NPC) are endemic in Far East Asia and commonly harbour Epstein-Barr virus (EBV) which is known to serve as a key oncogenic promoter. Human papillomavirus (HPV) is known to contribute to the pathogenesis of NPC. However, in Ghana these two viruses have not been linked to NPC prevalence. This study was designed to determine the HPV genotypes and EBV involved in NPC tissue biopsies. A retrospective study design involving 72 formalin-fixed paraffin-embedded tissue (FFPET) samples of NPC from 2006 to 2012 were retrieved from the Department of Pathology, University of Ghana School of Biomedical and Allied Health Sciences. Sections were taken for histological analysis and for DNA lysate preparation. The DNA lysates were subjected to polymerase chain reaction (PCR) analysis to determine the presence of HPV genotypes and EBV. HPV specific primers were used to type for fourteen HPV genotypes (HPV-16, 18, 6/11, 31, 33, 35, 44, 42, 43, 45, 56, 52, 58, and 59). Out of the 72 NPC biopsies analyzed by PCR, EBV DNA was present in 18 (25%) cases and HPV DNA in 14 (19.23%). High risk HPV (HR-HPV) genotypes 18 and 31 were associated with the NPC. There were 3 (4.2%) cases of coinfection by both viruses. The EBV DNA present in the undifferentiated variant of the NPC and the histopathology of the NPC in Ghana is similar to the type described in endemic areas.

MANAGEMENT OF PROSTATE CANCER IN ACCRA, GHANA

INTRODUCTION

Africans living with prostate cancer in Africa face problems of early diagnosis and appropriate treatment.

AIM

To study the clinical incidence of prostate cancer, risk factors, TNM stage, their management and outcomes.

METHODS

A prospective study of Prostate Cancer cases managed at Korle Bu Teaching Hospital and hospitals in Accra, diagnosed by history, abnormal PSA/DRE, physical examination and histologically confirmed by biopsy from 2004 to 2013 was carried out. The cases were TNM staged and managed by approved protocol.

RESULTS

There were 669 cases with a mean age 70±0.045SE years, median Gleason Score of 7, organ confined Prostate Cancer(PC) in 415(62%), locally advanced in 167(25%) and metastatic Prostate Cancer in 87(13%) cases. The cases were followed for median of 10 months to ≥ 84 months. Organ confined cases were managed by: Radical Prostatectomy (RP) 92 (13.8%) with a mortality of 0.3%; brachytherapy 70 (10.5%) with a mortality of 0.1% and External Beam Radiotherapy (EBRT) 155 (23%) with a mortality 0.7%. In all, 98 men constituting (14.1%) cases with a mean age of 75+0.25SE years, life expectancy <10 years were treated by hormonal therapy with a mortality of 1.7%. Twenty cases who were for active surveillance (GS6), PSA <10ng/ml, life expectancy <10 years later all opted for EBRT. Locally advanced cases 25% all had neoadjuvant hormonal therapy then Brachytherapy in 3 (0.4%) mortality 0.15% and EBRT in 64 (9.5%), mortality 0.59%. Hormonal therapy was given in 100 (15%) locally advanced cases, mortality 5%. Metastatic prostate cancer cases (13%) were managed by hormonal therapy, mortality 6%.

CONCLUSION

Improved facilities and dedicated skilled teams led to a significant rise in proportion of organ confined Prostate Cancer from 15.3% to 62% curable by Radical Prostatectomy, brachytherapy or EBRT with longer disease free survival.

Hepatitis B virus genotypes among chronic hepatitis B patients reporting at Korle-Bu teaching hospital, Accra, Ghana

Introduction

Knowledge of hepatitis B virus (HBV) genotype is an important predictive variable which might have an impact in management and treatment of patients with chronic hepatitis B infection. In Ghana very little information is available on hepatitis B genotypes. This study was conducted to determine the distribution of HBV genotypes circulating among chronic hepatitis B patients reporting at the Korle-Bu Teaching Hospital (KBTH), Accra, Ghana.

Methods

Blood samples (10 ml) were collected from 250 consenting patients. DNA was extracted and amplified using polymerase chain reaction technique. Restriction fragment length polymorphism (RFLP) was used for the detection of genotypes.

Results

Out of the 250 chronic hepatitis B patients who were HBsAg positive, 91 (36.4%) were males aged 29.8 ± 9.1 and 159 (63.6%) females aged 33± 12.1 years. HBV DNA was detected in 111 (44.4%) but only 58 (52%) of these were typeable. These were classified as genotype A, 8 (7.2%); genotype D, 3 (2.7%) and genotype E, 47 (42.3%). Our results did not show any association between the infecting genotype and age (X²= 0.923; p-value=0.623) or gender (X²= 0.283, p= 0.579).

Conclusion

Consistent with similar studies worldwide, the results suggest that genotypes A, D and E were the genotypes circulating among chronic hepatitis B patients who reported to the Korle-Bu Teaching Hospital with genotype E being the most predominant and therefore constitutes an important public health concern. We recommend further epidemiological studies to understand the implication of genotype E in terms of disease progression and treatment.

Giardia lamblia infections in children in Ghana

INTRODUCTION

Though giardiasis is an important public health problem in Ghana, several aspects of its epidemiology, particularly the molecular epidemiology has not been investigated adequately. This could be a major hindrance to effective surveillance and control of giardiasis in the country. The study was carried out to determine the prevalence, risk factors and genotypes of Giardia lamblia infecting children at a paediatric hospital in Ghana.

METHODS

A total of 485 patients including 365 diarrhoea and 120 non-diarrhoea children were enrolled into the study. Stool samples were collected and analysed for parasite presence using microscopy, ELISA and PCR. Positive samples were subsequently characterized into assemblages by PCR-RFLP, and further confirmed with sequencing of the glutamate dehydrogenase (gdh) gene. Epidemiological data on demographic, clinical and behavioral features of the study subjects were also collected.

RESULTS

Prevalence of G. lamblia infections in diarrhoea and non-diarrhoea children were 5.8% and 5% respectively (P>0.5). Sequence data confirmed Giardia lamblia assemblage B as the predominant genotype in both diarrhoea and non-diarrhoea cases. There was no significant association of G. lamblia infection with any of the epidemiological variables investigated.

CONCLUSION

Our findings suggest that assemblage B could be the predominant genotype causing giardiasis in children. Increased public health education focusing on good sanitary practices, particularly among mothers and children, could decrease the risk of G. lamblia infection.

Coping strategies of HIV-affected households in Ghana

Background

HIV and negative coping mechanisms have a cyclical relationship. HIV infections may lead to the adoption of coping strategies, which may have undesired, negative consequences. We present data on the various coping mechanisms that HIV-affected households in Ghana resort to.

Methods

We collected data on coping strategies, livelihood activities, food consumption, and asset wealth from a nationally representative sample of 1,745 Ghanaian HIV-affected households. We computed coping strategies index (CSI), effective dependency rate, and asset wealth using previously validated methodologies.

Results

Various dehumanizing coping strategies instituted by the HIV-affected households included skipping an entire day’s meal (13%), reducing portion sizes (61.3%), harvesting immature crops (7.6%), and begging (5.6%). Two-thirds of the households were asset poor. Asset-poor households had higher CSI than asset-rich households (p <0.001). CSI were also higher among female-headed households and lower where the education level of the household head is higher. Households caring for chronically ill members recorded higher CSI in comparison with their counterparts without the chronically ill (p < 0.05).

Conclusions

Institution of degrading measures by HIV-affected households in reaction to threat of food insecurity was prevalent. The three most important coping strategies used by households were limiting portion size (61.3%), reducing number of meals per day (59.5%) and relying on less expensive foods (56.2%). The least employed strategies included household member going begging (5.6%), eating elsewhere (8.7%) and harvesting immature crop (7.6%).

Given that household assets, and caring for the chronically ill were associated with high CSI, a policy focusing on helping HIV-affected households gradually build up their asset base, or targeting households caring for chronically ill member(s) with conditional household-level support may be reasonable.

Enhanced FGFR signalling predisposes pancreatic cancer to the effect of a potent FGFR inhibitor in preclinical models

Background:

Fibroblast growth factor receptor (FGFR) signalling has been implicated in pancreas carcinogenesis. We investigated the effect of FGFR inhibition in pancreatic cancer in complementary cancer models derived from cell lines and patient-derived primary tumour explants.

Methods:

The effects of FGFR signalling inhibition in pancreatic cancer were evaluated using anti-FRS2 shRNA and dovitinib. Pancreatic cancers with varying sensitivity to dovitinib were evaluated to determine potential predictive biomarkers of efficacy. Primary pancreatic explants with opposite extreme of biomarker expression were selected from 13 tumours for in vivo dovitinib treatment.

Results:

Treatment with anti-FRS2 shRNA induced significant in vitro cell kill in pancreatic cancer cells. Dovitinib treatment achieved similar effects and was mediated by Akt/Mcl-1 signalling in sensitive cells. Dovitinib efficacy correlated with FRS2 phosphorylation status, FGFR2 mRNA level and FGFR2 IIIb expression but not phosphorylation status of VEGFR2 and PDGFRβ. Using FGFR2 mRNA level, a proof-of-concept study using primary pancreatic cancer explants correctly identified the tumours' sensitivity to dovitinib.

Conclusion:

Inhibiting FGFR signalling using shRNA and dovitinib achieved significant anti-cancer cancer effects in pancreatic cancer. The effect was more pronounced in FGFR2 IIIb overexpressing pancreatic cancer that may be dependent on aberrant stimulation by stromal-derived FGF ligands.

A phase II multicentre study of ziv-aflibercept in combination with cisplatin and pemetrexed in patients with previously untreated advanced/metastatic non-squamous non-small cell lung cancer

BACKGROUND

This study evaluated the efficacy and safety of ziv-aflibercept in combination with cisplatin and pemetrexed in non-small cell lung cancer (NSCLC).

METHODS

This single arm, multicentre phase II trial enrolled patients with previously untreated, locally advanced or metastatic non-squamous NSCLC. Patients received intravenous ziv-aflibercept 6 mg kg(-1), pemetrexed 500 mg m(-2), and cisplatin 75 mg m(-2), every 21 days for up to six cycles. Maintenance administration of ziv-aflibercept was to continue until disease progression, intolerable toxicity or other cause for withdrawal. The co-primary end points were objective response rate (ORR) and progression-free survival (PFS). Planned sample size was 72 patients.

RESULTS

The study was closed prematurely because of three confirmed and two suspected cases of reversible posterior leukoencephalopathy syndrome (RPLS). A total of 42 patients were enrolled. Median age was 61.5 years; 55% were male, 86% Caucasian and 50% had Eastern Cooperative Oncology Group performance status (ECOG PS)=0. A median of four cycles of ziv-aflibercept was administered. The most common treatment-emergent adverse events (TEAEs) of any grade were nausea (69%) and fatigue (67%), with hypertension (36%) as the most common grade 3/4 TEAE. Of the 38 evaluable patients, ORR was 26% and median PFS was 5 months.

CONCLUSION

Cases of RPLS had been observed in other studies in the ziv-aflibercept clinical development programme but the rate observed in this study was higher than previously observed. This might be related to declining renal function and/or hypertension. Although ORR and PFS were in accordance with most historical first-line NSCLC studies, this combination of ziv-aflibercept/cisplatin/pemetrexed will not be further explored in NSCLC.

A multicenter phase 1 study of PX-866 in combination with docetaxel in patients with advanced solid tumours

Background:

This phase I, dose-finding study determined the safety, maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D), pharmacokinetics, and antitumour activity of PX-866, a phosphatidylinositol 3-kinase inhibitor, combined with docetaxel in patients with incurable solid tumours.

Methods:

PX-866 was administered at escalating doses (4–8 mg daily) with docetaxel 75 mg m⁻² intravenously every 21 days. Archived tumour tissue was assessed for potential predictive biomarkers.

Results:

Forty-three patients were enrolled. Most adverse events (AEs) were grade 1 or 2. The most frequent study drug-related AE was diarrhoea (76.7%), with gastrointestinal disorders occurring in 79.1% (docetaxel-related) and 83.7% (PX-866-related). No dose-limiting toxicities were observed. The RP2D was 8 mg, the same as the single-agent MTD. Co-administration of PX-866 and docetaxel did not affect either drug's PKs. Best responses in 35 evaluable patients were: 2 partial responses (6%), 22 stable disease (63%), and 11 disease progression (31%). Eleven patients remained on study for >180 days, including 8 who maintained disease control on single-agent PX-866. Overall median progression-free survival (PFS) was 73.5 days (range: 1–569). A non-significant association between longer PFS for PIK3CA-MUT/KRAS-WT vs PIK3CA-WT/KRAS-WT was observed.

Conclusion:

Treatment with PX-866 and docetaxel was well tolerated, without evidence of overlapping/cumulative toxicity. Further investigation with this combination is justified.

Prophylactic cranial irradiation in small-cell lung cancer: findings from a North Central Cancer Treatment Group Pooled Analysis

BACKGROUND

This pooled analysis evaluated the outcomes of prophylactic cranial irradiation (PCI) in 739 small-cell lung cancer (SCLC patients with stable disease (SD) or better following chemotherapy ± thoracic radiation therapy (TRT) to examine the potential advantage of PCI in a wider spectrum of patients than generally participate in PCI trials.

PATIENTS AND METHODS

Three hundred eighteen patients with extensive SCLC (ESCLC) and 421 patients with limited SCLC (LSCLC) participated in four phase II or III trials. Four hundred fifty-nine patients received PCI (30 Gy/15 or 25 Gy/10) and 280 did not. Survival and adverse events (AEs) were compared.

RESULTS

PCI patients survived significantly longer than non-PCI patients {hazard ratio [HR] = 0.61 [95% confidence interval (CI): 0.52-0.72]; P < 0.0001}. The 1- and 3-year survival rates were 56% and 18% for PCI patients versus 32% and 5% for non-PCI patients. PCI was still significant after adjusting for age, performance status, gender, stage, complete response, and number of metastatic sites (HR = 0.82, P = 0.04). PCI patients had significantly more grade 3+ AEs (64%) compared with non-PCI patients (50%) (P = 0.0004). AEs associated with PCI included alopecia and lethargy. Dose fractionation could be compared only for LSCLC patients and 25 Gy/10 was associated with significantly better survival compared with 30 Gy/15 (HR = 0.67, P = 0.018).

CONCLUSIONS

PCI was associated with a significant survival benefit for both ESCLC and LSCLC patients who had SD or a better response to chemotherapy ± TRT. Dose fractionation appears important. PCI was associated with an increase in overall and specific grade 3+ AE rates.

OT1-03-03: Effect of Tamoxifen Therapy on Inhibition of Tumor Suppressor p53 by Estrogen Receptor

Background: A large number of patients with estrogen receptor (ER)-positive tumors are resistant to tamoxifen (TAM). Although several plausible reasons for such resistance have been suggested, the mechanisms remain unclear. ER mediates effects of estrogen by promoting proliferation of breast cancer cells. Tumor suppressor protein p53 guards against tumorigenesis by preventing proliferation of cells with genomic damage. Dr. Das's laboratory previously reported that ER binds and functionally suppresses wild type p53 in human breast cancer cells and xenograft tumor tissue, and TAM is capable of inhibiting this interaction. We hypothesize that relieving suppression of wild type p53 by ER could be an important mechanism underlying TAM action in breast cancer. To test this hypothesis, we have initiated a pilot randomized clinical trial of 50 women with newly diagnosed ERa-positive breast cancer.

Specific Aims: 1) To investigate the effect of a short pre-surgical intervention with TAM on the ER-p53 interaction in ER-positive, p53 wild type breast tumors and 2) To confirm the wild type status of p53 and analyze the functional status of the p53 pathway by monitoring expression of selected p53 target genes in tumors that have and have not been treated with TAM.

Trial design: A randomized clinical trial in the pre-surgical setting was proposed with either TAM 20mg for four weeks vs. no intervention. Patients randomized to the TAM arm will undergo multiple pharmacokinetic and phamacodynamic measurements of TAM metabolites and genotyping for common polymorphisms of TAM metabolism genes, CYP2D6 and CYP3A4/5. Fresh tumor tissue will be harvested from all patients at the time of surgery for analysis of ER-p53 protein interaction using tissue chromatin immunoprecipitation (tissue ChIP) assay. p53 gene status will be determined by sequencing. RNA and protein expression of ER, p53, and a selected group of ER and p53 target genes in the diagnostic core biopsy and surgical specimens will be analyzed by quantitative real-time PCR (qRTPCR) and immunohistochemistry (IHC). TAM metabolites will also be measured in the tumor and the surrounding benign tissue.

Eligibility criteria: Women greater or equal to eighteen years of age diagnosed with ER-positive invasive breast cancer (approximately 1cm in size) who will undergo primary surgical excision for their initial therapy are eligible. Women must not be pregnant, be on current hormonal therapy, or have a history of hypercoagulable syndrome or prior arterial or venous thrombosis.

Statistical methods: Descriptive statistics such as frequencies and relative frequencies will be computed for all categorical variables. Numeric variables will be summarized using simple descriptive statistics such as mean, standard deviation, and quartiles. Ninety-five percent confidence intervals will be computed. ChIP data will be subjected to Fisher's Exact Test. IHC date will be analyzed by Wilcoxon-Mann-Whitney test.

Present accrual and target accrual: We have accrued 17 patients to date and plan to accrue a total of 50 patients, 25 in each arm.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT1-03-03.

Hepatitis E virus infection among pig handlers in Accra, Ghana

OBJECTIVE

To determine the correlates of hepatitis E virus infection (HEV) in a sample of persons who work with pigs.

DESIGN

Cross-sectional study.

SETTING

Three pig farms in the Greater Accra Region of Ghana.

SUBJECTS

Persons who work with pigs seen at the selected pig farms between the months of January and May 2008.

RESULTS

One hundred and five persons who work with pigs voluntarily completed a risk-factor questionnaire and provided blood samples for unlinked anonymous testing for the presence of antibodies to HEV. The median age of participants was 36.5 +/- 15.0 years (range 12-65 years). Of the 105 subjects tested, HEV seroprevelance was 38.1%. On multivariate analysis, the independent determinants of HEV infection were being employed on the farm for less than six months (odds ratio (OR) 9.1; 95% confidence interval (95% CI) 1.0-81.4 and having piped water in the household and/or on the farm (OR 3.9; 95% CI 0.4-90.8).

CONCLUSION

Consistent with similar studies worldwide, the results of our studies revealed a high prevalence of HEV infection in persons who work with pigs. Further studies need to be done to isolate, characterise the virus and define the clinical and epidemiological significance of HEV infection in this population.

A phase II study of cetuximab and radiation in elderly and/or poor performance status patients with locally advanced non-small-cell lung cancer (N0422)

BACKGROUND

Non-small-cell lung cancer (NSCLC) is a disease of the elderly. Seeking a tolerable but effective regimen, we tested cetuximab + radiation in elderly and/or poor performance status patients with locally advanced NSCLC.

PATIENTS AND METHODS

Older patients [≥ 65 years with an Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1, or 2] or younger patients (performance status of 2) received cetuximab 400 mg/m(2) i.v. on day 1 followed by weekly cetuximab 250 mg/m(2) i.v. with concomitant radiation of 6000 cGy in 30 fractions. The primary end point was the percentage who lived 11+ months.

RESULTS

This 57-patient cohort had a median age (range) of 77 years (60-87), and 12 (21%) had a performance status of 2. Forty of 57 (70%) lived 11+ months, thus exceeding the anticipated survival rate of 50%. The median survival was 15.1 months [95% confidence interval (CI) 13.1-19.3 months], and the median time to cancer progression was 7.2 months (95% CI 5.8-8.6 months). No treatment-related deaths occurred, but 31 patients experienced grade 3+ adverse events, most commonly fatigue, anorexia, dyspnea, rash, and dysphagia, each of which occurred in <10% of patients.

CONCLUSION

This combination merits further study in this group of patients.

Sorafenib, a dual Raf kinase/vascular endothelial growth factor receptor inhibitor has significant anti-myeloma activity and synergizes with common anti-myeloma drugs

Multiple myeloma is characterized by increased bone marrow neovascularization driven in part by vascular endothelial growth factor (VEGF). In addition, the Ras/Raf/MEK/ERK pathway is critical for the proliferation of myeloma cells and is often upregulated. Sorafenib (Nexavar) is a novel multi-kinase inhibitor that acts predominantly through inhibition of Raf-kinase and VEGF receptor 2, offering the potential for targeting two important aspects of disease biology. In in vitro studies, sorafenib-induced cytotoxicity in MM cell lines as well as freshly isolated patient myeloma cells. It retained its activity against MM cells in co-culture with stromal cells or with interleukin-6, VEGF or IGF; conditions mimicking tumor microenvironment. Examination of cellular signaling pathways showed downregulation of Mcl1 as well as decreased phosphorylation of the STAT3 and MEK/ERK, as potential mechanisms of its anti-tumor effect. Sorafenib induces reciprocal upregulation of Akt phosphorylation; and simultaneous inhibition of downstream mTOR with rapamycin leads to synergistic effects. Sorafenib also synergizes with drugs such as proteasome inhibitors and steroids. In a human in vitro angiogenesis assay, sorafenib showed potent anti-angiogenic activity. Sorafenib, through multiple mechanisms exerts potent anti-myeloma activity and these results favor further clinical evaluation and development of novel sorafenib combinations.

Bacterial contamination of blood and blood components in three major blood transfusion centers, Accra, Ghana

Reports from studies conducted in several countries indicate a high incidence of bacterial contamination of donor blood. The prevalence of bacterial contamination of blood and its products in Ghana is not known. This study was conducted to determine the prevalence of bacterial contamination of blood and its products at the three major blood transfusion centers in the Greater Accra Region of Ghana. Stored whole blood and its products were cultured on different media, and isolates were identified using standard biochemical and bacteriological methods. The susceptibility of the isolates to selected antimicrobial agents was also determined by the disc diffusion method. The overall prevalence rate was 9% (28/303; whole blood, 13% [24/192]; plasma, 3% [2/79]; platelet, 9% [2/22]). The Gram-positive bacteria isolated were coagulase-negative Staphylococcus, S. aureus, and Bacillus spp., and the Gram-negative organisms were Yersinia enterocolitica, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. The Gram-positive bacteria were sensitive to cloxacillin, erythromycin, tetracycline, and gentamicin but resistant to penicillin, ampicillin, cefuroxime, and cotrimoxazole, while the Gram-negative bacteria were sensitive to amikacin and gentamicin but resistant to chloramphenicol, tetracycline, ampicillin, cefuroxime, cefotaxime (except Y. enterocolitica), and cotrimoxazole. Our results suggest that bacterial contamination of blood and its products is prevalent in Ghana.

Prevalence of human immunodeficiency virus infection among tuberculosis suspect patients in Accra, Ghana

BACKGROUND

Acquired immunodeficiency syndrome is a major public health concern worldwide, particularly in Ghana, where recent reports indicate an increase of the disease. A close association between infection with human immunodeficiency virus (HIV) and tuberculosis (TB) is well known. A previous study showed a 16.8% seroprevalence of HIV in TB patients on admission at the chest clinic of the Korle-Bu teaching hospital. However this was in severely ill patients on admission and there was a likely selection bias. This study was therefore designed to determine the prevalence of HIV infection among patients suspected of TB attending the laboratory of the chest clinic of the Korle-Bu Teaching hospital, Accra, Ghana.

METHODS

Pulmonary TB was diagnosed using clinical, sputum smear microscopy and chest x-ray features. HIV was determined using particle agglutination test (HIV-1 and HIV-2) and synthetic peptide-based immunoassay (Peptilav I and II ELISA).

RESULTS

Of the 277 subjects examined, 108 (39%) were diagnosed as TB. The seroprevalence of HIV was 46.2% in all TB suspect patients. It was 47.2% and 45.6% in those with and without tuberculosis, respectively. in both groups, the peak age distribution of subjects positive for HIV antibodies was from 20 to 59 years.

CONCLUSION

The results show a great increase in HIV seroprevalence in TB patients in Korle-Bu. The high HIV seroprevalence suggests that subjects suspected of TB should be tested for HIV as well.

Cytokines and adhesion molecules expression in the brain in human cerebral malaria

Although the role of systemic proinflammatory cytokines, IL-1β and TNF-α, and their up-regulation of adhesion molecules, ICAM-1, VCAM-1 and E-Selectin, in the pathogenesis of cerebral malaria (CM) is well established, the role of local cytokine release remain unclear. Immunohistochemistry (IHC) was used to compare the expression of ICAM-1, VCAM-1, E-Selectin, IL-1β, TNF-α and TGF- β at light microscopic level in cerebral, cerebellar and brainstem postmortem cryostat sections from 10 CM, 5 severe malarial anemia (SMA), 1 purulent bacterial meningitis (PBM), 2 non-central nervous system infections (NCNSI) and 3 non-infections (NI) deaths in Ghanaian children. Fatal malaria and Salmonella sepsis showed significantly higher vascular expression of all 3 adhesion molecules, with highly significant co-localization with sequestration in the malaria cases. However, there was negligible difference between CM and SMA. TGF-β showed intravascular and perivascular distribution in all cases, but expression was most intense in the PBM case and CM group. TNF-α and IL-1β showed prominent brain parenchymal staining, in addition to intravascular and perivascular staining, in only the PBM case and CM group. The maximal expression of all 6 antigens studied was in the cerebellar sections of the malaria cases. Endothelial activation is a feature of fatal malaria and Salmonella sepsis, with adhesion molecule expression being highly correlated with sequestration. IL-1β and TNF-α are upregulated in only cases with neurodegenerative lesions, whilst TGF-β is present in all cases. Both cytokines and adhesion molecules were maximally upregulated in the cerebellar sections of the malaria cases.

Clinical studies of pemetrexed and gemcitabine combinations

Pemetrexed (ALIMTA) is a novel multitargeted antifolate that inhibits thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. This agent is broadly active in a wide variety of solid tumors, including breast cancer, bladder cancer, mesothelioma, non-small-cell lung cancer, pancreatic cancer and ovarian cancer. Pemetrexed has also shown clinically relevant activity in combination with gemcitabine. This combination has been, and continues to be evaluated for the treatment of a number of malignancies, including non-small cell lung and ovarian cancer. A recently published randomized trial of different sequences has identified the sequence of pemetrexed on day 1 followed by gemcitabine on day 1 and gemcitabine on day 8, every 21 days as the most efficacious and least toxic sequence.

High-level cerebellar expression of cytokines and adhesion molecules in fatal, paediatric, cerebral malaria

Although the roles played by systemic tumour necrosis factor (TNF) and interleukin 1beta (IL-1beta), and their upregulation of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and E-selectin, in the pathogenesis of human cerebral malaria (CM) are well established, the role of local cytokine release, in the brain, remains unclear. Immunohistochemistry was therefore used to compare the expression of ICAM-1, VCAM-1, E-selectin, IL-1beta, TNF and transforming growth factor beta (TGF-beta) at light-microscope level, in cryostat sections of cerebral, cerebellar and brainstem tissues collected, post-mortem, from Ghanaian children. Among the 21 children investigated were 10 cases of CM, five of severe malarial anemia (SMA), one of purulent bacterial meningitis (PBM), two of non-central-nervous-system infection (NCNSI) and three children who had no infection (NI) when they died. Parasitised erythrocytes were detected in all of the sections from the cases of fatal malaria (CM and SMA), and sequestered leucocytes were present in most of the sections from the CM cases (but none of the sections from the SMA cases). Significantly elevated vascular expression of all three adhesion molecules investigated was detected in the brains of the 15 cases of fatal malaria and one of the cases of NCNSI (a child with Salmonella septicaemia), and in the malaria cases this showed highly significant co-localization with the areas of erythrocyte sequestration. In terms of the levels of expression of ICAM-1, VCAM-1 and E-selectin, there were, however, negligible differences between the CM and SMA cases. Although TGF-beta showed intravascular and perivascular distribution in all the subjects, its expression was most intense in the PBM case and the CM group. Only in the sections from the PBM and CM cases did TNF and IL-1beta show prominent brain parenchymal staining, in addition to the intravascular and perivascular staining seen in all subjects. The highest observed expression of each of the six antigens studied was in the cerebellar sections of the malaria cases. Endothelial activation in the brain therefore appears to be a feature of fatal malaria and Salmonella sepsis, and in cases of fatal malaria is closely associated with leucocyte sequestration. In the present study, IL-1beta and TNF were only up-regulated in the brains of children with neurodegenerative lesions, whereas TGF-beta was present in all cases.

A phase II trial of a combination of pemetrexed and gemcitabine in patients with metastatic breast cancer: an NCCTG study

PURPOSE

This phase II study was undertaken to define the efficacy and toxicity of pemetrexed in combination with gemcitabine in patients with metastatic breast cancer.

PATIENTS AND METHODS

Patients with measurable metastatic breast cancer who had previously received an anthracycline and a taxane in either the adjuvant or metastatic setting were treated with gemcitabine 1250 mg/m2 (intravenous; days 1 and 8) and pemetrexed 500 mg/m2 (intravenous; day 8) every 21 days.

RESULTS

Fifty-nine patients received a median of five cycles (range one to 22) of treatment and were followed until death or for a median of 28 months (range 19.4-36.6) among living patients. Fourteen partial responses for an overall response rate of 24% [95% confidence interval (CI) 16% to 39%] were documented. Nine (15%; CI 5% to 32%) patients had stable disease for >6 months. The median survival time was 10.3 months (95% CI 8.3-18.9) and the 1 year survival rate was 49% (95% CI 38% to 64%). The median time to progression was estimated to be 3.7 months (95% CI 2.3-5.3). The most common grade 3 or 4 toxicities were neutropenia and thrombocytopenia in 83% and 27% of patients, respectively. Fourteen percent of patients experienced febrile neutropenia. Other common grade 3 or 4 non-hematological toxicities included fatigue (17%), dyspnea (15%), rash (7%) and anorexia (5%).

CONCLUSIONS

The combination of pemetrexed and gemcitabine is clinically active, with an overall response rate of 24% in patients with metastatic breast cancer who have previously been treated with an anthracycline and a taxane. Myelosuppression (66% grade 4 neutropenia and 14% febrile neutropenia) was the major treatment-related toxicity observed for this combination.

A phase II trial of imatinib (ST1571) in patients with c-kit expressing relapsed small-cell lung cancer: a CALGB and NCCTG study

BACKGROUND

The aim of the present study was to evaluate the clinical activity of imatinib mesylate in patients with recurrent and refractory c-kit-expressing small-cell lung cancer.

PATIENTS AND METHODS

Patients with c-kit-expressing SCLC (> or =1+ by immunohistochemistry) were enrolled in two groups. Arm A included patients with disease progression <3 months and arm B included patients with disease progression > or =3 months after previous treatment. Imatinib was administered at a dose of 400 mg b.i.d. continuously, with a cycle length of 28 days. A single stage Simon design with a planned interim analysis was used to evaluate the 16-week progression free rate in each arm.

RESULTS

A total of 29 evaluable patients were entered into the study (seven in arm A, median age 68; 22 in arm B, median age 64.5). Median number of treatment cycles was one in both arms. Grade 3+ non-hematologic adverse events were seen in 15 (52%) patients, with nausea, vomiting, dyspnea, fatigue, anorexia and dehydration each occurring in at least 10% of patients. Median survival was 3.9 and 5.3 months and median time to progression was 1 and 1.1 months for arms A and B, respectively. Enrollment to arm A was temporarily suspended prior to reaching interim analysis due to striking early disease progression (29%), early deaths (29%) and patient refusal (42%). No objective responses and no confirmed stable disease > or =6 weeks were seen in either arm. Accrual was permanently terminated to both arms as only one patient was progression-free at 16 weeks.

CONCLUSION

Imatinib failed to demonstrate any clinical activity in spite of patient selection for c-kit-expressing SCLC. Our results strengthen the collective evidence that prediction of efficacy of novel therapeutic agents based on target expression, rather than pathway activation (for example, through activating mutations), may not be a valid paradigm for drug development.

Cryptosporidium Spp., a frequent cause of diarrhea among children at the Korle-Bu Teaching Hospital, Accra, Ghana

This report presents the results of a study conducted at the Child Health Department, Korle-Bu Teaching Hospital, Accra, Ghana, between the months of October 2001 and June 2002. Stool samples from 227 children with diarrhea and 77 children without diarrhea, aged less than 5 years, were tested for Cryptosporidium spp. Prevalence rates were 27.8 and 15.6% in children with and without diarrhea, respectively. Cryptosporidium infection was found to be high in children between the ages of 6 and 24 months. Cryptosporidium spp. was more common in malnourished children, but was not isolated in children under 6 months of age who were exclusively breastfed. Neither the presence of domestic animals, abdominal pain, blood in stool, nausea, vomiting, nor the consumption of untreated water was associated with Cryptosporidium spp. infection. Shigella, Salmonella, and yeast-like organisms were the most frequently identified enteropathogenic bacteria. In summary, this study demonstrates the prevalence of Cryptosporidium spp. among Ghanaian children.

Prevalence of antibodies to syphilis among blood donors in Accra, Ghana

Several infectious diseases have been found to be associated with transfusion of blood and blood components. Reports from studies conducted in many African countries indicate a high incidence of blood-borne pathogens such as syphilis infections among healthy blood donors. The prevalence of syphilis antibodies in blood donors in Ghana is not known. This study was therefore conducted in order to determine the prevalence of antibodies to syphilis among blood donors seen between the months of January and March 2003 at the National Blood Transfusion Service, Accra area (Blood Bank) at the Korle-Bu Teaching Hospital, Accra, Ghana. The presence of antibodies specific for syphilis was tested using Venereal Disease Research Laboratory and particle agglutination test kit. A sero-prevalence rate of 7.5% was found. Our sample of blood donors was largely comprised of male subjects (500 out of 536 donors, and only 1 out of the 36 screened female donors was positive), making sex comparisons statistically undesirable. In both sexes, the age distribution of subjects positive for syphilis antibodies was from 19 - 54 (median age, 32) years. In conclusion, our results indicate that syphilis is prevalent among healthy blood donors in Ghana, and that there is a need to introduce the screening of donated blood for syphilis in Ghana.

Evaluation of a rapid serological chromatographic immunoassay for the diagnosis of pulmonary tuberculosis in Accra, Ghana

Advances in serologic assays for tuberculosis (TB) have made serology an attractive surveillance tool. The sensitivity, specificity, and predictive value of these new assays have been well established. We employed an immunochromatographic serodiagnostic test for detecting antibodies (immunoglobulin [Ig] G, IgA, and IgM) specific for mycobacteria-specific antigen 60 (A60) in the serum of suspected TB patients (n=310) attending the Chest Clinic of the Korle-Bu Teaching Hospital, Accra, Ghana. Compared to the gold standard, sputum culture, the performance indexes of the test kit indicated a sensitivity of 80% and a specificity of 98.2%, respectively. The positive predictive value and the likelihood ratios for positive and negative results were 96.6, 44.4, and 0.2%, respectively, when compared to sputum culture. Our results suggest that the serodiagnostic test kit may be a valuable tool for the diagnosis of TB, and can provide simple and satisfactory results, particularly in cases in which TB is clinically difficult to diagnose by the usual clinical and laboratory tests.

Human T-lymphotropic type-1 virus specific antibody detected in sera of HIV/AIDS patients in Ghana

Serum samples from 124 acquired immunodeficiency syndrome (AIDS) hospitalized patients at the Fevers Unit, Korle-Bu Teaching Hospital, Accra, Ghana, were examined by the particle agglutination test for antibodies to human T-lymphotropic virus type 1 (HTLV-1) core proteins. The subjects included 84 males and 40 females, aged 16 to 54 years. Specific antibodies were detected in only 14 out of the 124 sera samples, giving an overall prevalence rate of 11.29%. The incidence was lower in males (5.95%; 5/84) than in females (22.50%; 9/40) (P<0.05). In both sexes, the age distribution of subjects positive for HTLV-1 antibodies ranged from 35 to 54 years. The prevalence rate reported herein is too low to suggest an association of HTLV-1 with AIDS, though it may indicate an opportunistic infection of AIDS patients by HTLV-1. Whether HTLV-1 is an underlying disease association or whether HTLV-1 plays some auxiliary role in the acquisition and progression of AIDS remains to be determined.

A phase I study of sequential irinotecan and 5-fluorouracil/leucovorin

BACKGROUND

Irinotecan (CPT-11) and 5-fluorouracil (5-FU)/leucovorin are active agents in colorectal cancer. A sequence-dependent synergism of SN-38 followed by 5-FU/leucovorin in vitro led us to conduct a phase I trial of CPT-11 followed by 5-FU/leucovorin to determine the maximum tolerated dose (MTD) and toxicities of this regimen and to obtain preliminary indications of its activity in patients with advanced solid tumors.

PATIENTS AND METHODS

Fifty-six patients were enrolled in sequential cohorts to receive escalating doses of CPT-11 (90 min infusion) on day 1, followed by leucovorin 20 mg/m(2) (intravenous push) and 5-FU (90 min infusion) on days 2-5 of each 21-day cycle.

RESULTS

A total of 347 treatment cycles (median 4, range 1-25) were administered. Dose-limiting toxicities were diarrhea, neutropenia and fatigue. Nine patients with colorectal cancer and one with gastric cancer had partial or minor responses. Eight of the 10 had prior chemotherapy.

CONCLUSIONS

CPT-11 and 5-FU/leucovorin, as constituents of this novel mechanism-based schedule, have promising activity in patients who have received prior chemotherapy. The recommended phase II/III starting doses are CPT-11 275 mg/m(2) over 90 min on day 1, and 5-FU 400 mg/m(2) plus leucovorin 20 mg/m(2) on days 2-5 every 21 days. This combination can be administered safely to this schedule if there is strict adherence to the 90 min infusion time for both CPT-11 and 5-FU.

Farnesyl transferase inhibitors as anticancer agents

Protein farnesylation catalysed by the enzyme farnesyl protein transferase involves the addition of a 15-carbon farnesyl group to conserved amino acid residues at the carboxyl terminus of certain proteins. Protein substrates of farnesyl transferase include several G-proteins, which are critical intermediates of cell signalling and cytoskeletal organisation such as Ras, Rho, PxF and lamins A and B. Activated Ras proteins trigger a cascade of phosphorylation events through sequential activation of the PI3 kinase/AKT pathway, which is critical for cell survival, and the Raf/Mek/Erk kinase pathway that has been implicated in cell proliferation. Ras mutations which encode for constitutively activated proteins are found in 30% of human cancers. Because farnesylation of Ras is required for its transforming and proliferative activity, the farnesyl protein transferase inhibitors were designed as anticancer agents to abrogate Ras function. However, current evidence suggests that the anticancer activity of the farnesyl transferase inhibitors may not be simply due to Ras inhibition. This review will discuss available clinical data on three of these agents that are currently undergoing clinical trials.

A randomized phase II study of sequential docetaxel and doxorubicin/cyclophosphamide in patients with metastatic breast cancer

BACKGROUND

Docetaxel has yielded promising response rates as a component of doxorubicin-based combination schedules in patients with metastatic breast cancer, including docetaxel/doxorubicin and docetaxel/doxorubicin/cyclophosphamide (AC). This randomized two-stage phase II study was conducted to evaluate sequential treatment with docetaxel and AC as first-line treatment in patients with recurrent or metastatic breast cancer previously untreated with chemotherapy for metastatic disease.

PATIENTS AND METHODS

Thirty-three patients were randomized to either docetaxel (100 mg/m(2)) on day 1 of a 21-day cycle for three cycles followed by AC (60/600 mg/m(2)) on day 1 of a 21-day cycle for three cycles (n = 17) or vice-versa (n = 16), without prophylactic granulocyte colony-stimulating factor support. In addition, we compared pre-treatment serum sErbB1 and sErbB2 protein concentrations with that of an age- and menopausal status-matched group of healthy women, and examined changes in serum sErbB1 and sErbB2 protein concentrations in these two treatment schedules. Data from each one of the two arms of the trial (docetaxel then AC, or AC and then docetaxel) were analyzed separately.

RESULTS

Enrollment was suspended after the first-stage of accrual, based on statistical design. Confirmed objective response rates after six cycles of treatment were 35% [95% confidence interval (CI) 14% to 62%] with docetaxel then AC and 38% (95% CI 15% to 65%) with AC then docetaxel. Dose reductions were frequent and mostly due to grade 4 neutropenia. Median survival time was 2.5 years in the docetaxel then AC group, and 1.1 years in the AC then docetaxel group. Serum sErbB1 concentrations were not significantly different between the study patients and healthy women, and did not change significantly after three and six cycles of treatment. In contrast, serum sErbB2 concentrations were significantly higher in the study patients compared with healthy women and tended to decrease after three and six cycles of treatment.

CONCLUSIONS

Response rates at the end of six cycles of treatment, which led to termination of accrual after the first stage using either the sequence of docetaxel first or docetaxel after AC chemotherapy, were lower than anticipated. However, median survival times and median progression-free survival times are similar to those reported in other studies. These data further suggest that additional studies to assess whether serum sErbB2 concentrations are useful predictors of responsiveness to chemotherapy are warranted.

Novel pharmacological agents in clinical development for solid tumours

For decades, cancer therapy has focused on DNA-directed mechanisms of cytotoxicity, utilising agents with limited efficacy and significant toxicity. Recent advances in tumour biology have elucidated the molecular pathways implicated in the pathogenesis and progression of cancers and have resulted in the discovery of a variety of novel molecular targets for therapeutic intervention. Promising novel agents targeting signal transduction pathways, cell cycle regulation, angiogenesis and apoptosis are in clinical testing and are discussed in this review.

Gemcitabine and pemetrexed disodium combinations in vitro and in vivo

Pemetrexed disodium (ALIMTA) is a novel antimetabolite that inhibits at least three folate-dependent enzymes, thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyltransferase. Pemetrexed disodium is broadly active in a wide variety of solid tumours, including non-small cell lung, breast, bladder, head and neck and ovarian cancers. Gemcitabine is a broadly active pyrimidine nucleoside antimetabolite, which is approved for the treatment of pancreatic and non-small cell lung cancers. Three preclinical studies have been reported that show cytotoxic synergy between gemcitabine and pemetrexed. Clinical activity with this combination has been observed in a phase I study, with partial responses in three of five patients previously treated for non-small cell lung cancer. An international phase II study of this combination in non-small cell lung cancer is ongoing.

Current status of clinical trials of farnesyltransferase inhibitors

Farnesyltransferase inhibitors represent a new class of agents that target signal transduction pathways responsible for the proliferation and survival of diverse malignant cell types. Although these agents were developed to prevent a processing step necessary for membrane attachment and maturation of Ras proteins, recent studies suggest that farnesyltransferase inhibitors block the farnesylation of additional cellular polypeptides, thereby exerting antitumor effects independent of the presence of activating ras gene mutations. Clinical trials of two farnesyltransferase inhibitors--the tricyclic SCH66336 and the methylquinolone R115777--as single agents have demonstrated disease stabilization or objective responses in 10 to 15% of patients with refractory malignancies. Combinations of farnesyltransferase inhibitors with cytotoxic chemotherapies are yielding complete and partial responses in patients with advanced solid tumors. A phase I trial of R115777 in refractory and relapsed acute leukemias induced responses in 8 (32%) of 25 patients with acute myelogenous leukemia (including two complete remissions) and in two of three with chronic myelogenous leukemia in blast crisis. In patients with solid tumors, accessible normal tissues such as peripheral blood lymphocytes or, perhaps more germane to epithelial malignancies, buccal mucosa have provided surrogate tissues that allow confirmation that farnesyltransferase is inhibited in vivo at clinically achievable drug doses. In conjunction with the R115777 acute leukemia trial, serial measurements provided evidence of farnesyltransferase enzyme inhibition, interference with farnesyltransferase function ( ie, protein processing), and blockade of signal transduction pathways in leukemic bone marrow cells. Preclinical studies of farnesyltransferase inhibitor resistance and clinical trials of farnesyltransferase inhibitors in combination with other agents currently are in progress.

Ras signaling pathway proteins as therapeutic targets

Ras is a 21 kDa membrane-localized G protein that is coupled to receptor and non-receptor tyrosine kinase activation of downstream cytoplasmic and nuclear events. Mutated ras genes are common, and occur in a wide variety of human malignancies. These activating mutations result in constitutive signaling, thereby stimulating cell proliferation and inhibiting apoptosis. Preclinically, inhibitors of ras signaling revert ras-dependent cellular transformation, and cause regression of ras-dependent rodent tumor xenografts. The ras signaling pathway has therefore attracted considerable attention as a target for anticancer therapy. In this review, novel therapeutic approaches based on the inhibition of ras-mediated signaling, are described. The discussion will be limited to inhibitors which are currently in human clinical trials, and include inhibitors of ras processing, inhibitors of ras protein synthesis and inhibitors of downstream ras effectors.

The pharmacologic basis of high dose chemotherapy with haematopoietic stem cell support for solid tumours

The theoretical basis of high dose chemotherapy with haematopoietic stem cell support (HDT) for solid tumours is the presumption of a linear, steep dose-response relationship for chemotherapy conditioning agents. We review preclinical pharmacologic studies evaluating steep dose-response relationships for different chemotherapeutic agents, identified through a MED-LINE and CANCER-LIT search of the English medical literature from January 1966 to December 1999. Only BCNU, melphalan, nitrogen mustard, and the combination of thiotepa and cyclophosphamide demonstrated steep dose-response relationships over a wide dose-range. The pharmacologic evidence for the use of other antineoplastic agents for HDT in solid tumours is non-existent. More preclinical studies are needed for a rational development of this therapeutic approach for solid tumours.

Systemic chemotherapy in patients with renal failure

The administration of systemic chemotherapy to patients with moderate-to-severe organ impairment remains a challenge. In renal failure, guidelines for dose adjustments exist for very few chemotherapy agents. Subsequently, oncologists typically withhold treatment with systemic chemotherapy for patients with severe renal dysfunction. We present the case of a patient with metastatic transitional cell carcinoma of the bladder and renal failure who underwent successful systemic chemotherapy with paclitaxel and carboplatin. The data on systemic chemotherapy in patients with severe renal dysfunction are reviewed.

Advances in systemic therapy of small cell cancer of the lung

Over the last 20 years, progress in the therapy of small cell lung cancer has been painfully slow. Despite dramatic initial responses to chemotherapy, most patients relapse quickly with an overall 5-year survival of about 5%. Recent trials however offer some hope at changing this picture. Combining standard regimens with newer agents has doubled median survival in some cases. The use of novel targeted agents holds the promise of significantly increasing the survival in this disease, with manageable toxicity. This review outlines current treatment strategies, summarizes recent clinical trials and offers a view of what the next 5 years may hold for the treatment of small cell lung cancer.

Blocking oncogenic Ras signaling for cancer therapy

The Ras gene product is a monomeric membrane-localized G protein of 21 kd that functions as a molecular switch linking receptor and nonreceptor tyrosine kinase activation to downstream cytoplasmic or nuclear events. Each mammalian cell contains at least three distinct ras proto-oncogenes encoding closely related, but distinct proteins. Activating mutations in these Ras proteins result in constitutive signaling, thereby stimulating cell proliferation and inhibiting apoptosis. Oncogenic mutations in the ras gene are present in approximately 30% of all human cancers. K-ras mutations occur frequently in non-small-cell lung, colorectal, and pancreatic carcinomas; H-ras mutations are common in bladder, kidney, and thyroid carcinomas; N-ras mutations are found in melanoma, hepatocellular carcinoma, and hematologic malignancies. The ras-signaling pathway has attracted considerable attention as a target for anticancer therapy because of its important role in carcinogenesis. In this review, the physiologic and biochemical properties of the Ras proteins, their mechanism of cell signaling, and their relation to human cancer will be discussed. Novel cancer therapeutic approaches based on the inhibition of Ras-mediated signaling, including inhibition of Ras processing, inhibition of Ras protein synthesis, and blockage of downstream Ras effectors, will be discussed.

Synergy of the protein farnesyltransferase inhibitor SCH66336 and cisplatin in human cancer cell lines

The enzyme protein farnesyltransferase, which catalyzes the first step in the posttranslational modification of ras and a number of other polypeptides, has emerged as an important target for the development of anticancer agents. SCH66336 is one of the first farnesyltransferase inhibitors to undergo clinical testing. In the present study, we examined the effect of combining SCH66336 with several classes of antineoplastic drugs in various human tumor cell lines. Flow cytometry indicated that SCH66336 had no effect on the cell cycle distribution of treated cells. Nonetheless, colony-forming assays revealed that the antiproliferative effects of SCH66336 and 5-fluorouracil were less than additive. In contrast, the effects of SCH66336 and melphalan were additive. Moreover, the combination of SCH66336 + cisplatin produced antiproliferative effects that were additive or synergistic over a broad range of clinically achievable concentrations in A549 non-small cell lung cancer cells and T98G human glioblastoma cells, but less than additive in MCF-7 breast, HCT116 colon, or BxPC-3 pancreatic adenocarcinoma cells. Examination of the effect of drug sequencing in A549 cells revealed synergism when cells were exposed to SCH66336 and then cisplatin and antagonism when drugs were administered in the opposite order. The additive and synergistic effects resulted in enhanced apoptosis with the SCH66336 + cisplatin combination. Additional studies failed to show any effect of SCH66336 on the formation or removal of platinum-DNA adducts, raising the possibility that SCH66336 is affecting survival of cisplatin-treated cells downstream of the DNA lesions. These observations suggest that SCH66336 exhibits additive or synergistic effects when combined with cisplatin in a sequence- and cell line-dependent fashion. Additional preclinical and clinical study of this combination appears warranted.

Phase I trial of gemcitabine and CPT-11 given weekly for four weeks every six weeks

BACKGROUND

Our previous studies have shown that the in vitro cytotoxicity of gemcitabine and SN-38, the active metabolite of irinotecan (CPT-11), is synergistic in human tumor cell lines.

PATIENTS AND METHODS

Twenty-four patients with solid tumors, refractory to standard chemotherapy or for whom no effective therapy existed (age range 31-74; 7 female, 17 male; ECOG PS 0 = 12, 1 = 11, 2 = 1), received gemcitabine and CPT-11 weekly for four weeks out of every six weeks. Fifty courses of treatment (median 2, range 1-8) were given through five dose levels of gemcitabine/CPT-11 (600/75, 800/75, 800/100, 1000/100, 1000/125 mg/m2).

RESULTS

Grade 3 and 4 neutropenia occurred in eight and two patients, respectively. Grade 3 and 4 thrombocytopenia occurred in one and three patients, respectively. Hematologic toxicity resulted in > or = 2 missed doses of treatment in two out of six patients and was therefore dose limiting at gemcitabine 1000 mg/m2 and CPT-11 125 mg/m2. Grade 3 and 4 diarrhea occurred in two and one patients, respectively. Other moderate non-hematologic toxicities included alopecia, anorexia, fatigue, nausea, vomiting, and weight loss.

CONCLUSIONS

The maximum tolerated dose for this study recommended for phase II testing is gemcitabine 1000 mg/m2 and CPT-11 100 mg/m2. A partial response was seen in transitional cell carcinoma.

Phase I trial of sequential administration of raltitrexed (Tomudex) and 5-iodo-2'-deoxyuridine (IdUrd)

Raltitrexed (Tomudex) is a specific inhibitor of thymidylate synthase with clinical activity in colorectal cancer. The combination of raltitrexed and 5-iodo-2'-deoxyuridine (IdUrd, a cytotoxic pyrimidine analog) resulted in increased IdUrd incorporation into DNA and exhibited in vitro synergism against colon and bladder human carcinoma cell lines. We designed a phase I trial to determine the MTD, pharmacokinetics, and biologic effects of escalating doses of the combination of IdUrd given as a 24-hour infusion after a raltitrexed 15-minute infusion every three weeks. Thirty-four patients received 95 courses of raltitrexed and IdUrd at doses ranging from raltitrexed 1 mg/m2 and IdUrd 750 mg/m2 to raltitrexed 2.5 mg/m2 and IdUrd 10,400 mg/m2. The median number of cycles administered was 2 (range 1-10). Dose limiting hematologic toxicity occurred at doses of raltitrexed 2.5 mg/m2 and IdUrd 10,400 mg/m2. In addition, we determined the mean plasma concentrations C(SS) of IdUrd, the iodouracil level at 22 hours and the IdUrd clearance. Raltitrexed did not appear to affect the pharmacokinetics of IdUrd in the dose range tested. The recommended phase II dose is raltitrexed 2 mg/m2 and IdUrd 10,400 mg/m2 repeated every three weeks. Evidence of potential antitumor activity was observed: 1 patient (with colon cancer) had a partial response while 15 others had stable disease.

Phase I study of the matrix metalloproteinase inhibitor, BAY 12-9566

BACKGROUND

Matrix metalloproteinases (MMPs) are involved in tumor invasion and metastasis and have been implicated in breast, ovarian, colorectal, and lung cancer growth. We undertook a phase I study of BAY 12-9566, an inhibitor of MMP-2, MMP-9, and MMP-3, in patients with solid tumors to determine its safety, pharmacokinetics, and effects on potential surrogate markers of biologic activity.

PATIENTS AND METHODS

BAY 12-9566 was orally administered daily at four dose levels; 400 mg daily, 400 mg b.i.d., 400 mg t.i.d., and 800 mg b.i.d. Drug disposition was determined on days 1 and 29 with weekly trough levels measured during the first four weeks. Plasma vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and urinary pyridinoline and deoxypyridinoline crosslinks were determined at baseline, once weekly for four weeks, and then every four weeks.

RESULTS

Thirteen patients were entered on trial. BAY 12-9566 was well tolerated, with only one grade 3 headache, one grade 3 anemia, one grade 3 thrombocytopenia, and no musculoskeletal effects. The median treatment duration was 57 days (range 7-560). Mean trough levels of BAY 12-9566 on day 28 ranged from 80.5 to 108.6 mg/l. Plasma trough levels were 1500-42,000-fold above the Ki's for MMP-2, MMP-3, and MMP-9 at the 800 mg p.o. b.i.d. dose level. There was no significant change in VEGF, bFGF, pyridinoline, and deoxypyridinoline crosslinks with BAY 12-9566 administration.

CONCLUSIONS

The recommended dose for further testing is 800 mg p.o. b.i.d.

Human 3'-phosphoadenosine 5'-phosphosulfate synthetase: radiochemical enzymatic assay, biochemical properties, and hepatic variation

Sulfation is a major pathway in the biotransformation of many drugs and other xenobiotic compounds. The sulfotransferase (SULT) enzymes that catalyze these reactions use 3'-phosphoadenosine 5'-phosphosulfate (PAPS) as a sulfate donor cosubstrate. The synthesis of PAPS from inorganic sulfate and ATP is catalyzed by PAPS synthetase (PAPSS). We previously cloned the genes for human PAPSS1 and PAPSS2 as a step toward pharmacogenetic studies of these enzymes. We have now developed a sensitive PAPSS radiochemical enzymatic assay for use in genotype-phenotype correlation analyses. This coupled assay uses the sulfation of 17beta-[(3)H]estradiol catalyzed by recombinant human SULT1E1 to measure PAPS, which has been generated by PAPSS during the initial step of the assay. SULT1E1 proved to be ideal for this application both because of its relative resistance to inhibition by ATP, a substrate for the PAPSS-catalyzed step, and because of its low K(m) values for both PAPS (58 nM) and estradiol (29 nM). After optimal PAPSS assay conditions had been established, substrate kinetic studies were performed with cytosol preparations from human liver and cerebral cortex, two tissues with very different expression patterns for PAPSS1 and PAPSS2 mRNA. Brain and liver cytosol PAPSS activities had apparent K(m) values for ATP of 0.26 and 0.62 mM, respectively, and for SO(4)(2-) of 0.08 and 0.31 mM, respectively. PAPSS activity was then measured in 83 human liver biopsy samples to determine the nature and extent of individual variation in this enzyme activity. An 18-fold variation was observed. This sensitive new radiochemical assay can now be used in pharmacogenetic studies of PAPSS in humans.

Gemcitabine and Pemetrexed disodium in treating breast cancer

Pemetrexed disodium (Alimta, LY231514) is a novel, multitargeted antifolate that inhibits thymidylate synthase, dihydrofolate reductase, and glycinamide ribonucleotide formyl transferase. This agent is broadly active in a wide variety of solid tumors, including breast cancer. Pemetrexed disodium has also shown clinically relevant activity in combination with gemcitabine (Gemzar). This combination is being evaluated for the treatment of metastatic breast cancer.