AI implementation in the UK landscape: Knowledge of AI governance, perceived challenges and opportunities, and ways forward for radiographers

INTRODUCTION

Despite the rapid increase of AI-enabled applications deployed in clinical practice, many challenges exist around AI implementation, including the clarity of governance frameworks, usability of validation of AI models, and customisation of training for radiographers. This study aimed to explore the perceptions of diagnostic and therapeutic radiographers, with existing theoretical and/or practical knowledge of AI, on issues of relevance to the field, such as AI implementation, including knowledge of AI governance and procurement, perceptions about enablers and challenges and future priorities for AI adoption.

METHODS

An online survey was designed and distributed to UK-based qualified radiographers who work in medical imaging and/or radiotherapy and have some previous theoretical and/or practical knowledge of working with AI. Participants were recruited through the researchers' professional networks on social media with support from the AI advisory group of the Society and College of Radiographers. Survey questions related to AI training/education, knowledge of AI governance frameworks, data privacy procedures, AI implementation considerations, and priorities for AI adoption. Descriptive statistics were employed to analyse the data, and chi-square tests were used to explore significant relationships between variables.

RESULTS

In total, 88 valid responses were received. Most radiographers (56.6 %) had not received any AI-related training. Also, although approximately 63 % of them used an evaluation framework to assess AI models' performance before implementation, many (36.9 %) were still unsure about suitable evaluation methods. Radiographers requested clearer guidance on AI governance, ample time to implement AI in their practice safely, adequate funding, effective leadership, and targeted support from AI champions. AI training, robust governance frameworks, and patient and public involvement were seen as priorities for the successful implementation of AI by radiographers.

CONCLUSION

AI implementation is progressing within radiography, but without customised training, clearer governance, key stakeholder engagement and suitable new roles created, it will be hard to harness its benefits and minimise related risks.

IMPLICATIONS FOR PRACTICE

The results of this study highlight some of the priorities and challenges for radiographers in relation to AI adoption, namely the need for developing robust AI governance frameworks and providing optimal AI training.

Abstract OT2-08-01: Personalized breast cancer screening in a population based study: Women Informed to Screen Depending On Measures of risk (WISDOM)

Background: WISDOM is a 100,000 healthy women preference-tolerant, pragmatic study comparing annual to personalized risk-based breast screening. The novelty of WISDOM personalized screening is the integration of previously validated genetic and clinical risk factors (age, family history, breast biopsy results, ethnicity, mammographic density) into a single risk assessment model that directs the starting age, timing, and frequency of screening. The goal of WISDOM is to determine if personalized screening, compared to annual screening, is as safe, less morbid, enables prevention, and is preferred by women. The study is registered on ClinicalTrials.gov, NCT02620852.

Methods: Women aged 40-74 years with no history of breast cancer or DCIS, and no previous double mastectomy can join the study online at wisdomstudy.org. Participants can elect randomization or self-select a study arm, and provide electronic consent and Release for Medical Information using DocuSign. For all participants, 5-year risk of developing breast cancer is calculated according to the Breast Cancer Screening Consortium (BCSC) model. Participants in the personalized arm undergo panel-based mutation testing, and their 5-year risk is calculated using the BCSC score combined with a Polygenic Risk Score (BCSC-PRS) that includes 75 single nucleotide polymorphisms (SNPs, increase to 229) known to increase breast cancer risk. SNPs and mutations (BRCA1, BRCA2, TP53, PTEN, STK11, CDH1, ATM, PALB2, and CHEK2) are assessed by saliva-based testing through Color Genomics. 5-year risk level thresholds are used to stratify for low-, moderate- and high risk. Risk stratification determines age to start, stop, and frequency of screening.

Enrollment: As of July 2018, the WISDOM study is open to all eligible women in California, North Dakota, South Dakota, Minnesota and Iowa. To date, 23,329 eligible women have registered and 14,393 women have consented to participate in the trial. We analyzed 3,255 participants who have completed risk assessment in the personalized arm. The median age was 56 years. 82% were Caucasian, 1% African-American, and 6% Asian. 9% self-reported as Hispanic. We are partnering with health insurers and self-insured companies using coverage with evidence progression. To strengthen generalizability, we are expanding to other states. WISDOM enrollment will continue past 2019.

Feasibility: To evaluate the addition of PRS, we used paired statistical tests (McNemar) to compare the distributions of BCSC, and BCSC-PRS risk estimates around low-risk (<1.3%), and very-high risk (>6%) thresholds, the latter corresponding to 5-year risk of a BRCA mutation carrier. The median 5-year risk was 1.5% (IQR 1.0-2.1%) using the BCSC model, and 1.4% (IQR 0.8-2.5%) using the BCSC-PRS model. The BCSC-PRS model classified more women into the low (<1%) and very high (≥6%) risk categories compared to the BCSC model (p < 0.001).

Conclusions: Our findings demonstrate that incorporating genetic variants into a validated clinical model is feasible and impacts risk classification compared to a model without genetic risk factors. Results at 5 years will reveal if this classification improves healthcare value by reducing screen volumes and costs without jeopardizing outcomes.

Citation Format: Acerbi I, Shieh Y, Madlensky L, Tice J, Ziv E, Eklund M, Blanco A, DeRosa D, Tong B, Goodman D, Nassereddine L, Anderson N, Harvey H, Layton T, Park HL, Petruse A, Stewart S, Wernisch J, Risty L, Koenig B, Sarrafan S, Firouzian R, Kaplan C, Hiatt R, Parker BA, Wenger N, Lee V, Heditsian D, Brain S, Stover Fiscalini A, Borowsky AD, Anton-Culver H, Naeim A, Kaster A, Talley M, van 't Veer LJ, LaCroix A, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, Esserman LJ. Personalized breast cancer screening in a population based study: Women Informed to Screen Depending On Measures of risk (WISDOM) [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 OT2-08-01.

A physiologically relevant 3D collagen-based scaffold-neuroblastoma cell system exhibits chemosensitivity similar to orthotopic xenograft models

3D scaffold-based in vitro cell culturing is a recent technological advancement in cancer research bridging the gap between conventional 2D culture and in vivo tumours. The main challenge in treating neuroblastoma, a paediatric cancer of the sympathetic nervous system, is to combat tumour metastasis and resistance to multiple chemotherapeutic drugs. The aim of this study was to establish a physiologically relevant 3D neuroblastoma tissue-engineered system and explore its therapeutic relevance. Two neuroblastoma cell lines, chemotherapeutic sensitive Kelly and chemotherapeutic resistant KellyCis83 were cultured in a 3D in vitro model on two collagen-based scaffolds containing either glycosaminoglycan (Coll-GAG) or nanohydroxyapatite (Coll-nHA) and compared to 2D cell culture and an orthotopic murine model. Both neuroblastoma cell lines actively infiltrated the scaffolds and proliferated displaying >100-fold increased resistance to cisplatin treatment when compared to 2D cultures, exhibiting chemosensitivity similar to orthotopic xenograft in vivo models. This model demonstrated its applicability to validate miRNA-based gene delivery. The efficacy of liposomes bearing miRNA mimics uptake and gene knockdown was similar in both 2D and 3D in vitro culturing models highlighting the proof-of-principle for the applicability of 3D collagen-based scaffolds cell system for validation of miRNA function. Collectively, this data shows the successful development and characterisation of a physiologically relevant, scaffold-based 3D tissue-engineered neuroblastoma cell model, strongly supporting its value in the evaluation of chemotherapeutics, targeted therapies and investigation of neuroblastoma pathogenesis. While neuroblastoma is the specific disease being focused upon, the platform may have multi-functionality beyond this tumour type.

STATEMENT OF SIGNIFICANCE

Traditional 2D cell cultures do not completely capture the 3D architecture of cells and extracellular matrix contributing to a gap in our understanding of mammalian biology at the tissue level and may explain some of the discrepancies between in vitro and in vivo results. Here, we demonstrated the successful development and characterisation of a physiologically relevant, scaffold-based 3D tissue-engineered neuroblastoma cell model, strongly supporting its value in the evaluation of chemotherapeutics, targeted therapies and investigation of neuroblastoma pathogenesis. The ability to test drugs in this reproducible and controllable tissue-engineered model system will help reduce the attrition rate of the drug development process and lead to more effective and tailored therapies. Importantly, such 3D cell models help to reduce and replace animals for pre-clinical research addressing the principles of the 3Rs.

eEF-2 kinase is a critical regulator of Warburg effect through controlling PP2A-A synthesis

Cancer cells predominantly metabolize glucose by glycolysis to produce energy in order to meet their metabolic requirement, a phenomenon known as Warburg effect. Although Warburg effect is considered a peculiarity critical for survival and proliferation of cancer cells, the regulatory mechanisms behind this phenomenon remain incompletely understood. We report here that eukaryotic elongation factor-2 kinase (eEF-2K), a negative regulator of protein synthesis, has a critical role in promoting glycolysis in cancer cells. We showed that deficiency in eEF-2K significantly reduced the uptake of glucose and decreased the productions of lactate and adenosine triphosphate in tumor cells and in the Ras-transformed mouse embryonic fibroblasts. We further demonstrated that the promotive effect of eEF-2K on glycolysis resulted from the kinase-mediated restriction of synthesis of the protein phosphatase 2A-A (PP2A-A), a key factor that facilitates the ubiquitin-proteasomal degradation of c-Myc protein, as knockdown of eEF-2K expression led to a significant increase in PP2A-A protein synthesis and remarkable downregulation of c-Myc and pyruvate kinase M2 isoform, the key glycolytic enzyme transcriptionally activated by c-Myc. In addition, depletion of eEF-2K reduced the ability of the transformed cells to proliferate and enhanced the sensitivity of tumor cells to chemotherapy both in vitro and in vivo. These results, which uncover a role of the eEF-2K-mediated control of PP2A-A in tumor cell glycolysis, provide new insights into the regulation of the Warburg effect.

Abstract P2-16-05: Efficacy of ABT-888 (veliparib) in patients with BRCA-associated breast cancer

Background: The potential for exploiting BRCA deficiencies with DNA repair inhibitors has both pre-clinical and clinical support. ABT-888 (veliparib), a DNA repair inhibitor initially thought to target Poly(ADP-Ribose) Polymerases (PARP), has demonstrated in vitro inhibition of BRCA1 and BRCA2 deficient mouse embryonic stell cells, with a larger effect on BRCA1 cells. We report on the pre-planned interim analysis of the efficacy of single agent veliparib in patients with either BRCA1 or BRCA2-associated stage IV breast cancer. Methods: BRCA 1 or 2 carrier patients with stage IV breast cancer, with measurable disease, without prior exposure to a PARP inhibitor or a platinum compound in the metastatic setting, were eligible. Velapirib was administered orally, at doses of 400 mg twice daily. Dose adjustments based on toxicity were permitted. Patients progressing on velapirib alone received carboplatin at an AUC of 5, IV, given Q 21 days, and velapirib 150 mg twice daily (the maximum tolerated dose [MTD] of the combination from our completed Phase I study: J Clin Oncol 30, 2012 [suppl; abstr 1024]). Patients were to be accrued from 7 NCI NO1- supported consortia. Initially 10 patients were to be accrued to each stratum (BRCA1 and BRCA2) to provide evidence of single agent activity. If there was sufficient activity to warrant consideration of velapirib as single agent therapy (defined as 2 or more confirmed partial [PR] or better responses out of 10 per stratum), an additional 12 patients would be accrued per stratum. Results: 20 evaluable patients (11 BRCA1 and 9 BRCA2 [1 in screening]) have been accrued, the majority with lung or liver as visceral metastatic sites of disease. Median age (range) is 46 (29-68) years. Tumors from 9 patients were hormone receptor positive. BRCA1 cohort: 4 of 11 patients are off treatment at a median of 2 months (1-4); 1 patient stopped velapirib due to toxicity (grade 2 rash/pruritus, grade 2 vomiting), 3 stopped for progressive disease (one with an unconfirmed PR). Seven patients are still on single agent veliparib with 1 unconfirmed PR, and 1 patient with two evaluations showing stable disease. BRCA2 cohort: 2 patients are off treatment at 2 months for progressive disease, 7 are still on treatment with 1 confirmed PR, and 3 unconfirmed PRs. Data on patients receiving combination of velapirib and carboplatin after progression is too early. Treatment-related toxicity is being updated and has so far been reported from 14 patients: 1 patient had grade 3 fatigue, 1 patient with liver metastasis had both grade 3 alanine aminotransferase elevation and grade 3 abdominal pain. Grade 2 toxicities occurring in more than 1 patient included nausea/vomiting (6 patients), chills (2 patients), and fatigue (2 patients). Conclusion: Velapirib has single agent activity in both BRCA1 and BRCA2-associated stage IV breast cancer patients, and is well-tolerated. Mature response, treatment, and toxicity data will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-05.

PilM/N/O/P proteins form an inner membrane complex that affects the stability of the Pseudomonas aeruginosa type IV pilus secretin

The highly conserved pilM/N/O/P/Q gene cluster is among the core set of genes required for cell surface expression of type IV pili and associated twitching motility. With the exception of the outer membrane secretin, a multimer of PilQ subunits, the specific functions of the products encoded by this gene cluster are poorly characterized. Orthologous proteins in the related bacterial type II secretion system have been shown to interact to form an inner membrane complex required for protein secretion. In this study, we provide evidence that the PilM/N/O/P proteins form a functionally equivalent type IVa pilus complex. Using Pseudomonas aeruginosa as model organism, we found that all four proteins, including the nominally cytoplasmic PilM, colocalized to the inner membrane. Stability studies via Western blot analyses revealed that loss of one component has a negative impact on the levels of other members of the putative complex. Furthermore, complementation studies revealed that the stoichiometry of the components is important for the correct formation of a stable complex in vivo. We provide evidence that an intact inner membrane complex is required for optimal formation of the outer membrane complex of the type IVa pilus system in P. aeruginosa, as PilQ stability is negatively affected in its absence. Finally, we show that, in the absence of the pilin subunit, the levels of membrane-bound components of the inner membrane complex are negatively regulated by the PilR/S two-component system, suggesting a role for PilR/S in sensing the piliation status of the cell.

Incidence of peripheral neuropathy in high-risk early-stage breast cancer patients receiving dose-dense paclitaxel in central Pennsylvania

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Background: Paclitaxel (P) is an important part of chemotherapy regimens for early breast cancer. Breast cancer survivors may be left with iaotrogenic peripheral neuropathy which can affect their quality of life. Methods: We conducted a retrospective, IRB approved, medical chart review to determine the rate of peripheral neuropathy in a tertiary care practice in central Pennsylvania. Patients had biopsy proven, newly diagnosed, high risk breast cancer. Patients were treated with a standard dose dense (DD) regimen where 4 cycles of adriamycin (A) 60 mg/m2/cyclophosphamide (C) 600 mg/m2 were followed by four cycles of paclitaxel (P) 175 mg/m2 every 2 weeks (Citron et al) between 7/2006 to7/2008 at Penn State Cancer Institute. All patients who received dose dense chemotherapy by a single provider were included (n=23). No peripheral neuropathy (PN) was reported before initiating paclitaxel, but 3 of 23 patients had type II diabetes. Electronic medical charts were reviewed and data was abstracted to analyze incidence of peripheral neuropathy. These data were compared to reported published data. Results: 22 pts received dose dense AC followed by P chemotherapy. 100% completed 4 cycles of AC and 87% complete 4 cycles of P. Overall, 82% developed neuropathy (32% with grade 1, 41 % with grade 2, 9 % with grade 3). Almost 30% of patients required gabapentin for control of neuropathic pain. 35% of patients with PN had symptoms persisting >3 months after chemotherapy. Conclusions: A considerable percentage of high risk, early breast cancer patients treated with AC followed by DD paclitaxel developed at least mild neurotoxicity. Rates of Grade 3 neurotoxicity were much higher (9%) than the previous CALGB-9741 study (4%). This may be related to regional pharmacogenomic differences. Although dense dose paclitaxel has been shown to improve disease free survival, PN affects most patients treated with paclitaxel and for some patients can have a prolonged impact on their quality of life. Future studies should attempt identify which patients are at risk for severe peripheral neuropathy.

No significant financial relationships to disclose.

The arm as a skin graft donor site in eyelid reconstruction

PURPOSE

To report the technique, success, and complications of using the arm as a donor site for full-thickness skin grafts used in eyelid and facial reconstruction.

METHODS

The charts of 42 patients were reviewed. The arm was used as a donor site for harvesting full-thickness skin grafts in 52 procedures of eyelid or facial reconstruction.

RESULTS

The size of skin grafts varied from 4.0 cm2 to 59.5 cm2. There were few recipient site complications: partial necrosis (n=2), severe contraction (n=2), and hair growth (n=4). Donor site complications included wound dehiscence (n=2) and hypertrophic scarring (n=2).

CONCLUSIONS

The arm is an acceptable donor site for harvesting full-thickness skin grafts for use in eyelid and facial reconstruction when either traditional donor sites are unavailable or a large amount of skin is needed.

Safety and efficacy of bisphosphonates beyond 24 months in cancer patients

PURPOSE

Bisphosphonate therapy has decreased the risk of skeletal complications associated with osteolytic bone lesions in patients with breast cancer and multiple myeloma. The large prospective studies have used 21 to 24 months of treatment. We studied the safety and efficacy of bisphosphonates in a subset of patients who received therapy for more than 24 months.

PATIENTS AND METHODS

Patients who received bisphosphonates (pamidronate or zoledronic acid) were identified. Data on skeletal events and laboratory parameters were gathered by chart review.

RESULTS

We studied 22 patients who received intravenous pamidronate or zoledronic acid for a duration of 3.6 years (range, 2.2 to 6.0 years). Prolonged therapy was well tolerated. No significant calcium, phosphorus, electrolyte, or WBC count abnormalities were encountered. There was a clinically insignificant decrease in hemoglobin and platelet count and an increase in creatinine in these patients. The fracture rate beyond 2 years was no greater than during the first 2 years of treatment. There were no stress fractures of long bones with prolonged therapy.

CONCLUSION

Prolonged treatment with the potent bisphosphonates pamidronate and zoledronic acid seems to be well tolerated and should be studied in prospective, randomized studies to document prolonged skeletal efficacy.

What did we learn about interdisciplinary collaboration in institutions?

The Interdisciplinary Generalist Curriculum (IGC) Project significantly advanced collaboration in the development of medical school curricula. As primary care faculty began to work together they encountered and overcame many challenges inherent in this new process. Inclusion of other faculty and departments, as well as dedicated support from the deans' offices, became necessary to the success of the projects. The continuation of successful collaborative projects in the medical school environment requires a common commitment of faculty, students, department chairs, and the dean's office; protected time; and involvement of faculty from other disciplines. This article outlines initial models of collaboration implemented in the IGC Project, followed by a description of the expected and unexpected outcomes of these collaborative efforts, and a discussion of the emergence of new ways of collaborating, with recommendations for successful collaborative efforts.

The Interdisciplinary Generalist Curriculum Project at Joan C. Edwards School of Medicine at Marshall University

The Interdisciplinary Generalist Curriculum (IGC) Project was designed to enhance interest in and support of generalism during the first two years of medical education. The original goals at Joan C. Edwards School of Medicine at Marshall University included the design and implementation of a core curriculum, Introduction to Patient Care (IPC), and enhancement of teaching excellence through faculty development. The core curriculum facilitated integration with the basic sciences and early introduction of physical examination skills, which were further developed in longitudinal clinical experiences with mentors. Although it was not originally intended to include basic scientists in the preceptor groups, they became important additions and created additional opportunities for interdisciplinary teaching and reciprocal learning. The mentor program, another well-received and intended curriculum change, evolved from a structured experience to a more flexible component of the curriculum. The program met the requirements of the IGC Project but 53% of the originally intended mentor time was achievable, due to curriculum constraints. Faculty development, another success, was originally intended to target IPC faculty but ultimately became a university-wide effort. The changes implemented as a result of the IGC Project continue to flourish beyond the funding period and have become integral aspects of the curriculum and the medical school.

A phase I dose-ranging trial of monthly infusions of zoledronic acid for the treatment of osteolytic bone metastases

Bisphosphonates are potent inhibitors of bone resorption and provide a therapeutic benefit for patients with bone metastases. Zoledronic acid is a highly potent, nitrogen-containing bisphosphonate. In the present trial, we assessed the safety and tolerability of increasing doses of zoledronic acid and its effects on urinary markers of bone resorption in cancer patients with bone metastases. Fifty-nine cancer patients with bone metastases were enrolled sequentially into one of 8 treatment groups in the core protocol. Each patient received a 5-min i.v. infusion of 0.1, 0.2, 0.4, 0.8, 1.5, 2, 4, or 8 mg zoledronic acid monthly for 3 months. Patients were monitored for clinical findings, adverse events, electrocardiograms, markers of bone resorption, as well as routine hematology, blood chemistries, and urinalysis. Thirty patients who demonstrated a radiographic response to treatment or stable disease in the core protocol were enrolled in a humanitarian extension protocol and continued to receive monthly infusions. Zoledronic acid was well tolerated at all dose levels. Adverse events reported by >10% of patients included skeletal pain, nausea, fatigue, upper respiratory tract infection, constipation, headache, diarrhea, and fever. Three patients in the core protocol and one patient in the extension protocol experienced grade 3 skeletal pain, "flu-like" symptoms, or hypophosphatemia, which were possibly related to treatment; all recovered completely. Adverse events were reported with similar frequency across all of the dosage groups. Zoledronic acid resulted in sustained, dose-dependent decreases in urinary markers of bone resorption. Zoledronic acid was safe and well tolerated and demonstrated potent inhibition of bone resorption.

Wrestling with typology: penetrating the "black box" of managed care by focusing on health care system characteristics

The health care system has undergone a fundamental transformation undermining the usefulness of the typology of the health maintenance organization, the independent practice association, the preferred provider organization, and so forth. The authors present a new approach to studying the health care system. In matrix form, they have identified a set of organizational and delivery characteristics with the potential to influence outcomes of interest, such as access to services, quality, health status and functioning, and cost. The matrix groups the characteristics by domain--financial features, structure, care delivery and management policies, and products--and by key roles in the health care system--sponsor, plan, provider intermediary organization, and direct services provider. The matrix is a tool for researchers, administrators, clinicians, data collectors, regulators, and other policy makers. It suggests a new set of players to be studied, emphasizes the relationships among the players, and provides a checklist of independent, control, and interactive variables to be included in analyses.

Overexpression of HER2 modulates bcl-2, bcl-XL, and tamoxifen-induced apoptosis in human MCF-7 breast cancer cells

Overexpression of HER2 in estrogen receptor (ER)-positive human breast tumors has been associated with resistance to endocrine therapy. Here we investigated the effects of HER2 on expression of apoptotic pathways and modulation of tamoxifen-induced apoptosis in ER-positive MCF-7 breast cancer cells. We report that HER2 overexpression in MCF-7 cells is accompanied by up-regulation of antiapoptotic Bcl-2 and Bcl-XL proteins and suppression of tamoxifen-induced apoptosis. In addition, human tumor cell lines that are both ER positive and overexpress HER2 also express enhanced levels of Bcl-2 compared to cells that are either ER positive or overexpress HER2 alone. Our findings suggest that possible deregulation of antiapoptotic Bcl-2 and Bcl-XL may be associated with the enhanced survival of HER2-overexpressing and ER-positive breast cancer cells treated with antiestrogens.

Intravenous vinorelbine as first-line and second-line therapy in advanced breast cancer

PURPOSE

We evaluated single-agent intravenous (IV) vinorelbine as first- and second-line treatment for advanced breast cancer (ABC) in patients who were not resistant to anthracyclines. Objective tumor response (TR) and toxicity were assessed.

PATIENTS AND METHODS

A total of 107 women were enrolled onto this multicenter, nonrandomized, open-label phase II study. Patients were stratified into first- and second-line treatment groups, based on prior treatment history. Vinorelbine was initially given at 30 mg/m2/wk, with dose modification for toxicity as indicated. Therapy was continued until disease progression or severe toxicity mandated withdrawal or until the patient asked to be removed from the study.

RESULTS

The objective response rate for all patients was 34% (95% confidence interval [CI], 25% to 44%): 35% (95% CI, 23% to 48%) for first-line patients and 32% (95% CI, 20% to 47%) for second-line patients. Nine first-line and three second-line patients obtained a complete response (CR). The median duration of objective response was 34 weeks in both groups. The overall survival durations of first- and second-line patients were 67 weeks and 62 weeks, respectively. Granulocytopenia was the predominant dose-limiting toxicity. Two patients died on study as a result of granulocytopenic sepsis.

CONCLUSION

Single-agent vinorelbine is an effective and well-tolerated agent for first- and second-line therapy of ABC. The results of this study confirm the findings of similar international trials and suggest vinorelbine should be considered a valid treatment option for patients with ABC and a potential component in future combination regimens for this disease.

A unifying hypothesis that links benign prostatic hyperplasia and prostatic intraepithelial neoplasia with prostate cancer. Invited comments

Prostatic Intraepithelial Neoplasia (PIN) and prostatic cancer (PCA) are not caused by infection, allergic reaction, inadequate immunological response, ischemia, ageing, systemic hormones, carcinogens, nor prostatic ductal contents. PIN and PCA are apparently caused by increased inner acinar pressure due to partially blocked draining ducts. Only this explanation can account for all the observations about PIN and PCA. All other possible causes are disproved by specific observations. In order to further clarify the cause of PIN and PCA, it is important to discover if peripheral zone lesions cluster around ducts or blood vessels. PIN patterns are the morphological precursors of both PCA and prostatic cysts. Different PIN patterns represent different adaptive stages to increasing inner acinar pressure. The immediate tissue cause of PCA is PIN disruption seeding the stroma with high-grade PIN (HGPIN) cells. These cells, programmed for adaptive proliferation and mobility in PIN, are sufficient in the stroma to cause all stages and patterns of invasive PCA. No mutated cells are necessary. For reasons given, the primary cause of the initial ductal blockage that results in PIN and PCA cannot be inflammation, stones, proteineous plugs, infarction, venus thrombosis, ductal hyperplasia, nor a constricted penis at ejaculation. Only benign prostatic hyperplasia (BPH) can explain all the facts and is thus the primary cause of the ductal blockage resulting in cysts, PIN and PCA. The main causes of BPH are apparently disuse atrophy of sexual and abdominal muscles, and atherosclerosis of the capsular branch of the prostatic artery, causes atypical adenomatous hyperplasia (AAH) in the transition zone. The resulting muscular and glandular atrophy decreases local and general growth inhibitors. New growth in the adult prostate is abnormal because epithelial cells grow into ducts rather into the stroma. In such ducts, the growths cannot receive stromal growth inhibitory signals, and thus continue to grow indefinitely and result in BPH, AAH-adenosis, blockage of ducts, cysts, PIN and PCA.

Elevated serum c-erbB-2 antigen levels and decreased response to hormone therapy of breast cancer

PURPOSE

Decisions concerning the use of hormone therapy to treat metastatic breast cancer are made on the basis of the presence of estrogen receptor (ER). Despite the presence of ER, half of patients will not respond to hormone treatment. The purpose of this study was to determine the effect of overexpression of HER-2/neu on the response to hormone therapy.

PATIENTS AND METHODS

Sera from 300 metastatic breast cancer patients with ER-positive (ER+), ER status unknown, or ER-/progesterone receptor-positive (PR+) randomized to receive second-line hormone therapy with either megestrol acetate or fadrozole were evaluated. An enzyme immunoassay (EIA) specific for the extracellular domain of the c-erbB-2 (HER-2/neu) oncogene product was used to detect serum levels.

RESULTS

Fifty-eight patients (19.3%) had elevated serum c-erbB-2 protein levels, using a selected cut-point of 30 U/mL. The response rate (complete responses [CRs] plus partial responses [PRs] plus stable disease [S]) to endocrine therapy was 40.9% in 242 patients with low serum c-erbB-2 levels and only 20.7% in 58 patients with elevated serum c-erbB-2 levels (P = .004). The median duration of treatment response was longer in the group with low serum c-erbB-2 levels (15.5 months) compared with the group with elevated serum c-erbB-2 levels (11.6 months). Survival was also significantly shorter in patients with elevated serum c-erbB-2 levels (P < .0001).

CONCLUSION

Patients with ER+/c-erbB-2+ metastatic breast cancer are less likely to respond to hormone treatment than ER+/c-erbB-2- patients. Their survival duration is also shorter.

Aromatase inhibitor development for treatment of breast cancer

Inhibition of estrogen production provides effective therapy for patients with hormone-dependent breast cancer. The source of estrogens in premenopausal women is predominantly the ovary, but after the menopause, estradiol is synthesized in peripheral tissues through the aromatization of androgens to estrogens. Uptake from plasma is the primary mechanism for maintenance of estradiol concentrations in breast cancer tissue in premenopausal women, whereas several steps may be operant in postmenopausal women. These include enzymatic synthesis of estradiol via sulfatase, aromatase, and 17 beta-hydroxysteroid dehydrogenase in the tumor itself. Aromatization of androgens secreted by the adrenal to estrogens in peripheral tissues and transport to the tumor via circulation in the plasma provides another means of maintaining breast tumor estradiol levels in postmenopausal women. These various sources contribute to the high tissue estrogen levels measured in breast tumor tissue. To effectively suppress tissue concentrations of estrogens and circulating estradiol in postmenopausal patients, various aromatase inhibitors have been developed recently. These include steroidal inhibitors such as 4-hydroxy-androstenedione as well as non-steroidal compounds with imidazole and triazole structures. The most potent of these, CGS 20267, is reported to suppress levels of active estrogens (i.e., estrone, estrone sulfatase, and estradiol) by more than 95%. This compound can suppress both serum and 24-hr urine estrogens to a greater extent than produced by the second generation inhibitor, CGS 16949A. CGS 20267 is highly specific since it does not affect cortisol and aldosterone serum levels during ACTH stimulation tests nor sodium and potassium balance in 24-hr urine samples.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased urinary excretion of pyridinium cross-links in cancer patients

Pyridinoline (PYD) and deoxypyridinoline (DPD), two collagen-based cross-links found in bone, were measured by high-performance liquid chromatography in urine samples from 65 control subjects and 97 patients with either untreated or progressive cancer. Patients with cancer had significantly (P < 0.001) higher urine concentrations of PYD and DPD than did control subjects. Both cross-links were increased in cancer patients with and without clinically detectable bone metastases, although patients with bone and liver involvement had higher mean concentrations. The mean concentrations of both cross-links were also significantly higher in the urine samples of inpatients than in an outpatient ambulatory population. These findings suggest that the measurement of PYD and DPD in urine may be useful in assessing bone metastases and bone resorption in cancer patients.

Increased urinary excretion of pyridinium cross-links in cancer patients

Pyridinoline (PYD) and deoxypyridinoline (DPD), two collagen-based cross-links found in bone, were measured by high-performance liquid chromatography in urine samples from 65 control subjects and 97 patients with either untreated or progressive cancer. Patients with cancer had significantly (P &lt; 0.001) higher urine concentrations of PYD and DPD than did control subjects. Both cross-links were increased in cancer patients with and without clinically detectable bone metastases, although patients with bone and liver involvement had higher mean concentrations. The mean concentrations of both cross-links were also significantly higher in the urine samples of inpatients than in an outpatient ambulatory population. These findings suggest that the measurement of PYD and DPD in urine may be useful in assessing bone metastases and bone resorption in cancer patients.

Interleukin-2 and interferon-alpha-2a outpatient therapy for metastatic renal cell carcinoma

The combination of interleukin-2 (IL-2) and interferon-alpha-2a (IFN-alpha-2a) has synergistic bioactivity in numerous preclinical model systems. Thirty-nine patients with metastatic renal cell cancer were treated with continuous intravenous infusion IL-2 for 4-5 days plus intramuscular IFN-alpha-2a 2-3 days a week for 4 consecutive weeks. A 2- to 4-week rest period was permitted after each 4 weeks of treatment. Thirty-one of the 39 patients were assessable for response determination. Response rate (six complete+seven partial remissions) was 33.3% for all patients, or 41.9% when the analysis was restricted to the 31 evaluable patients. Three patients were unable to tolerate treatment due to anorexia, weight loss, and severe fatigue. This therapy was relatively well tolerated in the outpatient setting in the other patients despite fever, chills, fatigue, anorexia, and weight loss. There was no correlation of response with site of metastases or bulk of disease.

Hormonal and immunological regulation of 2', 5'-oligoadenylate synthetase activity in human peripheral blood mononuclear cells

A newly developed method for assaying 2', 5'-oligoadenylate (2, 5A) synthetase activity by polyacrylamide gel electrophoresis was applied to peripheral blood mononuclear cells (PBMC) from normal subjects, HIV-positive subjects, and renal cell carcinoma (RCC) patients. Sex differences were observed in 2, 5A synthetase activity of PBMC from normal young adults, males having eightfold higher activities of this enzyme than females. Moreover, compared to values for postmenopausal (PM) females receiving estrogen replacement, untreated PM females had higher activities. Collectively, these results suggest that estrogen downregulates 2, 5A synthetase activity. Activities of 2, 5A synthetase were investigated in two disease states associated with altered immune function. In one patient with AIDS-related Kaposi's sarcoma, interferon-alpha (IFN-alpha) therapy increased 2, 5A synthetase activity twofold. In addition, combined therapy with interleukin-2 (IL-2) and IFN-alpha increased 2, 5A synthetase activities in eight of nine patients with RCC. Therefore, in patients receiving immunotherapy with IL-2 and IFN-alpha, our new assay could contribute to evaluation of immune stimulation. In general, studies in vitro confirmed these observations; however, exposure of PBMC from RCC patients revealed that in vitro IL-2 failed to induce this enzyme activity as it did in PBMC from normal volunteers.

Elevated soluble c-erbB-2 antigen levels in the serum and effusions of a proportion of breast cancer patients

PURPOSE

An enzyme-linked immunosorbent assay (ELISA) for the extracellular domain of the c-erbB-2 oncogene product was developed and evaluated to determine if soluble c-erbB-2 could be detected in the serum and effusions of cancer patients.

PATIENTS AND METHODS

Sera from 208 previously untreated or progressing cancer patients and 69 healthy controls were assayed in a double-antibody sandwich ELISA that used two monoclonal antibodies to the native extracellular domain of the c-erbB-2 receptor. Fisher's exact test was used to analyze the statistical significance of the frequency of elevated serum c-erbB-2 levels. Immunoprecipitation and Western blotting were used to characterize further the c-erbB-2 immunoreactivity in the serum of four breast cancer patients.

RESULTS

Sera from 12 of 53 patients (23%) with metastatic or locally advanced breast cancer, zero of 69 controls, one of 31 patients with ovarian cancer (3%), and two of 124 other cancer patients (2%) had soluble c-erbB-2 values greater than or equal to 5 U/mL. The number of breast cancer patients with elevated serum c-erbB-2 levels was significantly greater than that of the control group (P less than .0001), the ovarian cancer group (P less than .03), and the other cancers group (P less than .0001). Also, two of five effusions (40%) from breast cancer patients had an elevated soluble c-erbB-2 antigen level, compared with zero of 17 effusions from patients with benign diseases. Western blotting of four sera from breast cancer patients with elevated serum c-erbB-2 antigen levels produced bands of approximately 105 kD that seemed to correlate in intensity with increasing ELISA serum levels.

CONCLUSION

Serum c-erbB-2 levels are elevated in approximately one fourth of patients with locally advanced or metastatic breast cancer.

Elevated plasma platelet-derived growth factor B-chain levels in cancer patients

Platelet-derived growth factor (PDGF) is produced by a variety of normal and tumor cells in vitro. We have developed an enzyme-linked immunosorbent assay for the detection of the B-chain of PDGF. This assay can reliably detect 0.1 ng/ml of homodimeric recombinant PDGF B-chain and does not cross-react with recombinant PDGF-AA, epidermal growth factor, basic fibroblast growth factor, or transforming growth factor-beta. Citrated plasma from 72 control individuals had a PDGF B-chain (PDGF-B) level of 0.32 +/- 0.14 ng/ml (mean +/- SD) with a range of 0.10-0.69 ng/ml. The plasma platelet factor 4 (PF4) level was 97 +/- 70 ng/ml, with a range of 34-363 ng/ml. Citrated plasma was obtained from 131 cancer patients, and plasma PDGF-B was elevated in 19 (15%) of the patients. Both PDGF-B and PF4 were elevated in 14 (11%) of these patients, consistent with a platelet source of PDGF-B. In 5 patients (4%), however, PDGF-B was elevated and PF4 was not elevated compared to the control group. This last group of patients may have a tumor-derived source of PDGF-B which could be important in autocrine or paracrine growth stimulation of the tumor cells.

Specificity of low dose fadrozole hydrochloride (CGS 16949A) as an aromatase inhibitor

CGS 16949A (fadrozole hydrochloride), a potent cytochrome P450-mediated steroidogenesis inhibitor, blocks aromatase at low doses, but other biosynthetic steps at higher concentrations. Recent studies demonstrated inhibition of C11-hydroxylase, corticosterone methyloxidase-II, and deoxycorticosterone to corticosterone conversion with this agent at some-what higher concentrations than those required for blockade of aromatase. Based upon phase I studies, we postulated that relatively selective inhibition of aromatase might be possible if sufficiently low doses of CGS 16949A were used. A phase II study in 54 postmenopausal women with metastatic breast cancer examined the effects of low dose CGS 16949A on estrogen, mineralocorticoid, and glucocorticoid secretion. Two dose schedules and two dose levels were chosen based upon our prior dose escalation protocol study. Plasma estrone, estradiol, and estrone sulfate as well as urinary estrone and estradiol fell equally with 1.8-4 mg CGS 16949A given either on a twice daily or three times daily dose schedule. Isotopic kinetic studies demonstrated an 84% decrease in the rate of conversion of androstenedione to estrone to 0.40 +/- 0.07% (patients receiving 1.8-4 mg CGS 16949A daily). With these three regimens, basal levels of aldosterone and cortisol did not change significantly over a 12-week period of observation. Clinical examination, plasma electrolytes, and urinary sodium/potassium ratios suggested no biological evidence of mineralo-corticoid deficiency. ACTH-stimulated cortisol concentrations, however, were blunted at each dose level compared to pretreatment values. Nonetheless, peak responses exceeded 550 nmol/L, or a basal to peak difference of 190 nmol/L or greater, in 97% of instances. This probably reflected inhibition of C11-hydroxylase, since basal and ACTH-stimulated levels of 11-deoxycortisol were increased in response to CGS 16949A. Androstenedione and 17 alpha-hydroxyprogesterone also exhibited an upward trend in response to drug treatment. ACTH-stimulated aldosterone levels were blunted to a greater extent than those of cortisol, probably as a reflection of corticosterone methyloxidase type II blockade. Overall, the results suggest that CGS 16949A, at doses of 1.8-2 mg daily, blocks aromatase effectively and does not produce clinically important inhibition of cortisol or aldosterone biosynthesis. Thus, this agent can probably be used safely without glucocorticoid or mineralocorticoid supplementation.

Phase I study of interleukin-2 and interferon alfa-2a as outpatient therapy for patients with advanced malignancy

Twenty-six patients were treated in this phase I study with the combination of interleukin-2 (IL2) administered as a continuous infusion and interferon alfa-2a (IFN alpha-2a) administered intramuscularly to patients in an outpatient setting. The maximum-tolerated dose of both agents given as outpatient therapy was 2 x 10(6) U/m2 days 1 to 5 of IL2 and 9 x 10(6) U/m2 days 1, 3, and 5 of IFN alpha-2a for 4 consecutive weeks. A 2- to 4-week rest period was permitted after each 4 weeks of treatment. Fatigue was the treatment-limiting toxicity, and serious clinical or laboratory abnormalities occurred infrequently during this study. Patients with colon cancer metastatic to the liver tolerated treatment worse than patients with other tumors. Twelve of the 15 patients with renal cell cancer were assessable for response determinations. Of these 12 patients, three exhibited complete tumor regression, three have had partial objective regression, and three patients experienced stabilization of rapidly progressive disease. This therapy appears to be well tolerated in an outpatient treatment setting and shows significant activity against advanced renal cell cancer.

Disinfection associated spoilage of high water content ionic matrix hydrogels

Chemical analysis was carried out on clinically obtained hazy white hydrogel lenses that had been exposed to hydrogen peroxide disinfection. Analysis revealed that hazing was a surface phenomenon limited to high water content ionic matrix hydrogels (type IV), the type associated with the deposition of large amounts of lysozyme. We subjected unworn lenses to cycling studies involving doping in a variable artificial tear solution followed by exposure to disinfectant; this allowed us to duplicate the clinical situation and to derive a mechanism for this phenomenon. Hazing proved independent of the presence of hydrogen peroxide but dependent on the interaction of lens-bound lysozyme and stannate anion, the latter derived from sodium stannate present in the disinfectant as a stabilizing agent. Hazing is restricted to the type IV hydrogels because only these polymers have a sufficient number of anionic binding sites and are of sufficient porosity to allow the penetration and binding of a thick layer of lysozyme. Lysozyme is essential to hazing. No other tear protein is small enough to penetrate the hydrogel matrix or basic enough to have a marked affinity for the lens and to provide binding sites for stannate anion. These findings highlight the unique vulnerability of the type IV hydrogel to interaction with trace or transient ionic constituents in tears and lens care solutions.

Inhibition of aromatase with CGS 16949A in postmenopausal women

Potent, specific, and nontoxic inhibitors of aromatase would be useful for experimental studies and for use in the treatment of breast cancer and other disorders. We evaluated the effects of CGS 16949A, a nonsteroidal inhibitor of aromatase activity, in 12 postmenopausal women with breast cancer by measuring plasma and/or urinary androgens and estrogens after oral administration of CGS 16949A at doses ranging from 0.6-16 mg daily; each dose was given for 2 weeks. The 0.6-mg daily dose partially lowered estrogen levels, and maximum reduction occurred at doses of 2-16 mg daily. The fall in plasma and urinary estrogens without a concomitant fall in plasma androgens confirmed the blockade of aromatase activity. The degree of estrogen reduction was greatest for urinary estrone [to 27 +/- 3% (+/- SE) of basal], followed in order by plasma estrone sulfate (30 +/- 4%), plasma estrone (32 +/- 6%), urine estradiol (45 +/- 5%), and plasma estradiol (65 +/- 5%). Use of gas liquid chromatography-mass spectrometry techniques revealed similar patterns of reduction in catechol estrogens, estriol, and total urinary estrogens, suggesting that CGS 16949A does not alter the pathways of estrogen metabolism. The degree of estrogen reduction was remarkably similar to that caused with aminoglutethimide. At doses of 4-16 mg daily, CGS 16949A inhibited the C21-hydroxylase enzyme as well, based on concomitant rises in plasma androstenedione, testosterone, and 17 alpha-hydroxyprogesterone. This effect was insufficient to lower urinary cortisol excretion during the study. However, a statistically significant blunting of plasma cortisol responses to ACTH occurred with the 16-mg daily dose. No changes in plasma dehydroepiandrosterone sulfate levels or in thyroid, hematological, liver, or renal parameters were found. No significant side-effects of the medication were encountered. CGS 16949A appears to be a specific inhibitor of aromatase at doses below 4 mg daily and to lack apparent side-effects or toxic actions at doses up to 16 mg daily. This agent shows promise as a potent aromatase inhibitor for physiological and clinical studies.

A prospective randomized trial of alpha 2B-interferon/gamma-interferon or the combination in advanced metastatic renal cell carcinoma

Eighty-nine patients with advanced measurable metastatic renal cell carcinoma were entered into a prospective randomized trial comparing alpha-interferon to gamma-interferon and to the combination. The trial was performed in order to confirm the activity of gamma-interferon and assess the potential clinical synergism. Response rates were 5, 10, and 5%, respectively. The low response rate may have been due to the inability to raise the doses of the interferons to higher levels. Clinical synergy at this dose, route, and schedule of administration in renal cell carcinoma does not exist.

Androgen priming and chemotherapy in advanced prostate cancer: evaluation of determinants of clinical outcome

We conducted a randomized clinical trial in men with stage D2 prostate cancer to test whether androgen priming potentiates the efficacy of cytotoxic chemotherapy. Eighty-five men with progressive prostate cancer refractory to orchiectomy were treated continuously with aminoglutethimide and hydrocortisone to lower adrenal androgen secretion and were administered cyclic intravenous (IV) chemotherapy. The patients were randomized to receive either androgen priming or no additional treatment for three days before and on the day of chemotherapy. Median duration of follow-up was 43 months. Response rate (remission plus disease stabilization) was not significantly different between the stimulation and control arm when the analysis was restricted to evaluable patients (79% v 73%, respectively) or when it was extended to all patients (46% v 61%). Median duration of response was similar for the stimulation and control arm (9 and 10 months, respectively). Median survival was 10 months in the stimulation and 15 months in the control group (P = .0047). The androgen sensitivity of the tumors was supported by the greater toxicity in the stimulation arm associated with androgen administration. Factors found to be independently associated with improved clinical outcome included a high Karnofsky score and hematocrit, long duration of response to the initial castration, and normalization of an elevated serum acid phosphatase on treatment. We conclude that in this group of patients with advanced disease, androgen priming does not potentiate the efficacy of chemotherapy and is actually associated with a worse outcome. Furthermore, our data emphasize the heterogeneity of biologic behavior of prostate cancer.