Issue Of Oncology Research Articles

An association between successful engraftment of osteosarcoma patient-derived xenografts and clinicopathological findings.

Although osteosarcoma is a rare disease, with a global incidence rate estimated at 5.0/million/year, it is the most frequent primary bone sarcoma in children and adolescents. In translational research, the patient-derived xenograft (PDX) model is considered an authentic in vivo model for several types of cancer, as tumorgrafts faithfully retain the biological characteristics of the primary tumors. Our goal was to investigate the association between PDX formation and clinical findings of osteosarcoma patients and the ability of the model to preserve in immunocompromized mice the characteristics of the parental tumor. A fresh sample of the patient tumor obtained from a representative biopsy or from surgical resection was implanted into nude mice. When tumor outgrowths reached ~1,500mm³, fresh PDX fragments were re-transplanted into new hosts. Engraftment in mice was obtained after a latency period of 19-225 days (median 92 days) in 40.54% of the implanted samples. We confirmed the histopathological fidelity between the patient tumor and their respective established PDXs, including the expression of biomarkers. PDX take rate was higher in surgical resection samples, in post-chemotherapy surgical samples and in samples from patients with metastatic disease at presentation. In conclusion, we have shown that the osteosarcoma PDX model reliably recapitulates the morphological aspects of the human disease after serial passage in mice. The observation that more aggressive forms of osteosarcoma, including those with metastatic disease at presentation, have a higher efficiency to generate PDXs provides a promising scenario to address several unanswered issues in clinical oncology.

Issues in adolescent and young adult oncology in a developing country like India

Issues in adolescent and young adult oncology in a developing country like India

Fundamentals of personalised medicine in genetic testing-based oncology

The dynamic development of genetics in recent decades has opened a new era in medicine. Understanding molecular mechanisms of multiple human diseases has laid the foundations for targeted medical care, based on knowledge of the basic pathogenesis of these diseases. This breakthrough is particularly evident in oncology because knowledge of the molecular basis of cancer leads to a change in the paradigm of medical care for the patients. Gradually, classification and treatment based only on organ location and histopathologic diagnosis is becoming outdated, and so is the classification considering clinical stage and malignancy of the tumour. Personalized treatment for individual patients based on the profile of genetic changes is increasingly common. Defining the genetic aetiology of neoplastic diseases was an achievement that allowed for division of neoplasms into sporadic ones and those which develop due to hereditary predisposition. It also enabled establishment of the molecular classification of neoplasms and more and more frequently – targeted treatment and precise clinical prognosis. This article is the first one in a series of articles written by oncologists and geneticists. We hope that this series will be helpful for oncologists in understanding genetic problems and for geneticists – in understanding oncologic issues.

Real-World Data on Thromboprophylaxis in Active Cancer Patients: Where Are We? Are We Getting There?

Background: Cancer patients are at high risk for cancer-associated thrombosis (CAT). CAT is the second leading cause of death in these patients but it can be preventable with thromboprophylaxis. Patients and Methods: An observational, prospective, multicenter study aiming to record CAT management in clinical practice was conducted by the Hellenic Society of Medical Oncology (HeSMO). Results: A total of 426 active cancer patients (mean age 65.3 years, mean BMI: 26.1 kg/m2) who received thromboprophylaxis, were included from 18 oncology units. Tumor types were lung 25.1%, pancreas 13.9%, breast 8.7%, stomach 8.5%, ovarian 7.8%, and others 36%, while 69% had metastases. A total of 71% had a Khorana score ≤2 and 61% received High Thrombotic Risk Chemotherapy Agents (HTRCAs, e.g., platinum). For thromboprophylaxis patients received mainly Low Molecular Weight Heparins (LMWHs), on higher than prophylactic doses in 50% of cases. Overall, 16 (3.8%) thrombotic events and 6 (1.4%) bleeding events were recorded. Notably, patients on higher doses of LMWHs compared to patients who received standard prophylactic doses had 70% lower odds to develop thrombotic events (OR: 0.3, 95% CI: 0.10–1.0, p = 0.04). Conclusion: CAT is an important issue in oncology. Along with the Khorana score, factors as metastases and use of HTRCAs should also be taken into consideration. Thromboprophylaxis for active cancer patients with LMWHs, even on higher doses is safe and efficient.

Using the axillary reverse mapping technique to screen breast cancer patients with a high risk of lymphedema

BackgroundPreventing breast cancer-related lymphedema (BCRL) by preserving upper lymphatic drainage is still controversial. Our study aimed to use the axillary reverse mapping (ARM) technique in patients who underwent axillary surgery to analyse the correlation between postoperative residual ARM nodes and the occurrence of lymphedema, select candidates at high risk of developing lymphedema, and analyse the oncologic safety of ARM nodes.MethodsPatients undergoing sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) from October 2015 to February 2016 at the Peking University People’s Hospital Breast Center were prospectively recruited for the study. ARM was performed in all patients before surgery. ARM nodes were separated from SLNB and ALND specimens. Data were collected on the identification of ARM nodes before surgery, number of residual ARM nodes after surgery, nodal status, crossover rate, and correlation between residual ARM nodes and the occurrence of lymphedema.ResultsThe analysis included 78 patients. Of the 53 patients who underwent SLNB, crossover between ARM nodes and breast sentinel lymph nodes (SLNs) was seen in 22 specimens. The incidence of ARM node metastasis was 1.89% (1/53) and 25% (9/36) in the SLNB and ALND groups, respectively. The number of positive axillary lymph nodes was associated with the involvement of ARM nodes (P = 0.036). The incidence of residual ARM nodes was significantly higher in the SLNB group than in the ALND group (67.6% vs. 37.9%, P = 0.016). The incidence of lymphedema was significantly higher in the ALND group than in the SLNB group (33.3% vs. 5.4%, P = 0.003).ConclusionsFor SLNB, the ARM technique can help to resect SLNs more accurately. However, we do not recommend using the ARM technique to preserve ARM nodes in patients undergoing ALND due to oncologic safety issues. Nevertheless, we can predict patients undergoing axillary surgery who are more likely to have a high risk of lymphedema by assessing residual ARM nodes.Trial registrationThis study was registered on ClinicalTrials.gov in February 2016.The clinical trial registration number is NCT02691624.

Ethical Issues in Radiation Oncology During a Pandemic

Medicine in the United States has generally followed ethical principles espoused by Immanuel Kant where the individual patient takes priority in decision-making. With the advent of coronavirus disease 2019 as a major health event, radiation oncologists in some situations need to alter the manner in which they act with individual patients. The well-being of health care workers and society as a whole needs to be considered in management decisions. During the time of a pandemic, ethics principles may be based more on a utilitarian approach that emphasizes the common good. Thus, at times treatment decisions might result in delays in initiating therapy, modifying the radiation treatment course (such as to a short course rather than a long course of therapy), and the sequence of therapies, all to minimize viral exposure. It is important that altered therapy is based as much as possible on institutional or departmental decisions and, to the extent possible, not on a case-by-case basis. However, in all situations, we need to still respect the individual's autonomy and fully inform patients of our decisions and the reasons for those decisions.

Advanced Cancer Patient Knowledge of and Attitudes towards Tumor Molecular Profiling

Limited research has indicated that despite their overwhelming interest in tumor molecular profiling (MP),11Abbreviations: Accessibility and Remoteness Index of Australia (ARIA): an indication of the proximity of service centers relative to where the participant lives. Eastern Cooperative Oncology Group (ECOG): A performance status measure to quantify cancer patients' general well-being and activities of daily life. Molecular Therapeutics (MoST) Program: A research program which forms a component of the Australian Genomic Cancer Medicine Program. The Psychosocial Issues in Genomic Oncology (PiGeOn) Project: a longitudinal, mixed methods psychosocial sub-study of the MoST Program which aims to examine the psychosocial, behavioral and ethical impact of MP. Tumor molecular profiling (MP): a form of genomic testing, that involves characterization of tumor-derived DNA and RNA. cancer patients have poor knowledge about MP. The current study aimed to investigate demographic and psychological predictors of knowledge and perceived importance of MP in an advanced cancer patient cohort. Eligible participants had advanced solid cancers of any histological type with sufficient accessible tissue for MP and were enrolled in the Molecular Screening and Therapeutics (MoST) Program. A questionnaire was completed by 1074 participants (91% response rate) after consent, prior to undergoing MP. Overall, participants had poor to moderate knowledge of MP, yet perceived MP to have high importance. Higher education, speaking English at home, and greater satisfaction with the decision to undergo MP were associated with higher knowledge scores. More negative attitudes towards uncertainty, greater self-efficacy to cope with results, and lower perceived likelihood of cancer progression were associated with greater perceived importance of MP. Less educated participants and those who do not speak English at home will need clear explanations, visual aids and ample opportunity to ask questions about MP at the time of their decision-making. Clinicians also need to consider psychological factors relevant to patients' decision to pursue MP. Given the increased awareness of and demand for cancer genomic information and the rapidly changing nature of the actionability of MP, these findings will help inform an important ongoing debate on how to facilitate ethical and informed consent and manage patient expectations about personalized treatments.

Association of financial conflicts of interest with academic success among junior faculty in hematology and oncology.

2080 Background: Financial conflict of interest (COI) represents a complex issue in hematology and oncology. Little is known about when COIs develop during a career and if these correlate with early career success. We evaluated self-reported COIs for junior faculty members at 10 academic cancer centers and examined if these financial relationships with industry correlated with measures of academic career success. Methods: The study evaluated 229 assistant professors from the top 10 cancer centers based on the 2018 US News Cancer rankings. Faculty characteristics were determined from hospital websites including the number of years since completing fellowship. Data regarding National Institute of Health (NIH) funding were obtained. Industry funds (Sunshine Act funds; SAF) were identified from the Centers for Medicare & Medicaid Services (CMS) Open Payments database from 2013-2017. Self-reported COIs were obtained from the American Society of Clinical Oncology (ASCO) or American Society of Hematology (ASH) disclosures databases, and through review of disclosures from recent publications. Measures of academic success included h-index and number of publications. We assessed the influence of number of COIs and SAF received on measures of academic success. Results: Of the 229 included faculty, 45% were female, 39% graduated fellowship in 2015 or later, 35% were double-boarded, 40% had dual degrees and 15% received NIH funding. Approximately 46% of faculty had at least 1 COI. COIs (ASCO/ASH) were positively correlated with COIs self-reported in publications and total SAF (Spearman correlations 0.57 and 0.54, both P < 0.01). The development of COIs and the number of SAF increased with years in practice (Spearman correlations 0.37 and 0.28, both P < 0.01). COIs and SAF correlated with h-index (Spearman correlation 0.40 and 0.41, both P < 0.01). After adjusting for years since fellowship, linear regression demonstrated that log-transformed h-index and number of publications were associated with SAF (P < 0.01) and COIs (ASCO/ASH) (P = 0.01). Conclusions: Financial COIs were present in nearly half of the faculty and increased with more time since completing fellowship. Measures of academic success were positively correlated with COIs (ASCO/ASH) and SAF. These data suggest that cultivating industry relationships may aid faculty in establishing early academic success.

Oncology and pregnancy

Cancer and pregnancy are one of the most complex and controversial issues in oncology. This applies both to the clinical manifestation of the malignant process during pregnancy and pregnancy in a patient who has previously undergone treatment for a tumor. In both cases, medical, social, and ethical issues are closely intertwined.

Adrenocortical carcinoma: a literature review.

Adrenocortical carcinoma (ACC) is reported to be present in 3–10% of the population with most tumors presenting as benign tumors. Most cases of ACC are a sporadic accumulation of mutations over time. However, studies show a predisposition to various genetic mutations may contribute. Research over the last couple of decades has elucidated causes of ACC to be driven by several molecular changes that include inactivation of tumor suppressor genes and activation of a myriad of different oncogenes, DNA mutations, and epigenetic changes. The widely adopted staging of ACC is by European Network of Study of Adrenal Tumors (ENSAT) due to its correlations with clinical outcomes. At the time of presentation, a detailed history taking with attention to the history of symptoms of hormonal excess and family history of possible hereditary influence is the first step of evaluation. It is followed by a thorough physical examination for evaluation of ACC. Management of ACC poses a unique challenge as it involves oncologic and endocrine issues. Except for one trial, treatment guidelines are based on retrospective studies and non-randomized trials, and therefore the level of evidence is grade II to grade IV. Personalized therapy including identifying the actionable target in each patient is the future of ACC management. The knowledge base of ACC is evolving based on the basic science and clinical trials conducted by worldwide groups such as COMITE of France, ENSAT of Europe, TCGA project and American Australian Asian Adrenal Alliance (A5). Future studies should aim at clear molecular and clinical standardization. Recommended therapeutic strategies should be prospectively recorded.

IRIDIUM-192 RADIOTHERAPY BENEFITS IN THE MANAGEMENT OF GYNECOLOGICAL TUMORS.

Application of the most advanced radiation technologies of brachytherapy featuring the high dose ratesources i.e. 60Co and 192Ir within contemporary management protocols for gynecological cancer provides maximum dosedistribution in the clinical target along with minimal radiation exposure on surrounding organs and tissues. It involvesirradiation of large spaces with delivery of high therapeutic doses at the tolerance bound of «critical» organs (bladder,rectum) and tissues. Thus minimization of the early and late radiation complications, life span extent and quality oflife increase remain just the issues in contemporary radiation oncology requiring therefore the elaboration of radiobiological criteria along with substantiation of physiсо-engineering properties of the radiation sources. Taking intoaccount the basic radiobiological patterns will ensure a definitive further progress in the field of radiation oncology. to study and compare the biological effects of 192Ir with the effects of the reference gamma radiation 60Coand increase the effectiveness of brachytherapy using a 192Ir source. Radiobiological dosimetry on the basis of a test system of peripheral blood lymphocytesfrom the gynecological cancer patients with subsequent cytogenetic analysis of radiation-induced chromosomeaberrations was performed to study and compare the biological effects of 192Ir and reference 60Со γ-radiation, and toenhance the efficiency of 192Ir brachytherapy. Radiation markers, i.e. dicentric chromosomes with an accompanying paired fragment prevailed in thespectrum of radiation-induced damage. Variability of individual cytogenetic parameters of peripheral lymphocytesupon the first fraction of irradiation at the same dose of 5 Gy indicated an individual sensitivity of patients to the192Ir γ-irradiation. Comprehensive conservative treatment with adjuvant radiotherapy was applied to the patients(n = 98) having got secondary vaginal cancer stage II-III, T2-3N0-1M0. The high dose-rate (HDR) brachytherapy using 192Ir radiation sources was applied in the main study group (n = 37), HDR brachytherapy using 60Co radiation sourceswas applied in the control group (n = 35). The HDR brachytherapy with 192Ir and 60Co sources on the up-to-date technology intensive devices provides a high accuracy of dose distributions when irradiating the malignant neoplasms with minimized radiationexposure to the «critical» tissues. Treatment results are improved therefore. The use of 192Ir radiation sources compared with 60Co ones resulted in an increased throughput of treatment, enhanced tumor regression, and reduced incidence of radiation effects on the critical organs. Currently we perform the radiobiological studies on somatic cellsfrom cancer patients at the genetic, biochemical, biophysical, and cytological levels in order to receive a biologicalindication of radiation damage under the impact of 192Ir isotope. Continuation of clinical trials with radiobiologicalsupport will provide an opportunity to predict the early and late radiation complications and thus to provide a personalized approach in brachytherapy of cancer patients using the 192Ir sources of γ-rays.

Practical aspects of modern antineoplastic therapy in locally advanced and metastatic biliary tract cancer

Although gallbladder and biliary tract cancer is a rather rare group of diseases, it is among the pressing issues of modern oncology. Adequate surgery is the only curative method that can give a chance for recovery for a small proportion of patients at early stages of the disease. The scope of opportunities of drug therapy in biliary tract cancer is limited by the low effectiveness of the few currently available cytostatics. The addition of chemotherapy has little effect on the long-term outcome of surgery and other local interventions. Apparently, future treatments for these patients should be developed based on studies of targeted therapy and its combination with standard cytotoxic therapy, as well as possible targeting of anticancer immune response, which necessitates a search for immunotherapy efficacy predictors. The objective of this article is to consider the practical potential of drug therapy for biliary tract cancer and to review the studies that looked into molecular genetic targets and effective combinations of existing drugs, analyzing possible practical applications of the study results.

Immune structures of the greater omentum and their role in cancer metastasis

Omental malignant metastases are one of the challenging issues in oncology. The article provides a review of recent studies on the structure and functions of immune compartments of the greater omentum and their characteristic features that promote or inhibit tumor dissemination. The cellular composition of lymphoid nodules and milky spots is described, and functional and phenotypic properties of macrophages and lymphocytes are shown. Unique subpopulations of immunocompetent cells typical of this particular organ, as well as produced cytokines, are characterized. Particular attention is paid to the visceral adipose tissue surrounding immunocompetent cells and its effect on their functions. Analysis of the literature data has revealed a dual role, i.e. both protective and immunosuppressive one, of lymphoid structures of the greater omentum. The former is apparently associated mainly with a response to bacterial pathogens, while the latter is realized in cancer metastasis. The article focuses on immunological mechanisms that create local conditions for the growth and development of metastases, in particular, proinflammatory cytokines, chemokines, growth factors secreted by immune, tumor and mesothelial cells, and on the importance of the surrounding visceral adipose tissue for this process. The multidirectional prognostic significance of some local cellular and cytokine factors in cancer metastasis to the omentum and peritoneum is demonstrated. Possible approaches to treatment involving immunotherapy should be aimed at both elimination of tumor cells and overcoming the immunosuppressive environment. In this regard, reprogramming of macrophages, correction of hypoxic microenvironment, and the search for new control points seem promising.

Posttraumatic growth in parents of children and adolescents with cancer

Cancer can provoke negative psychological reactions. Nevertheless, coping with oncological issues can also result in positive psychological changes that demonstrate the strength of the human being, one of them being posttraumatic growth (PTG). The aim of this narrative review was to examine and analyze studies, published from 2000 to 2018 and available in different data sets, that focus on PTG in parents of children and adolescents with cancer in the pediatric context. Twenty studies were identified, including 2,422 subjects, mainly mothers (n=1,788). PTG was analyzed according to the differences among relatives, outcome and type of oncological disease, and its predictor factors. Fathers and mothers are both capable of developing PTG as a result of their children's disease, mothers being the ones who present higher levels. Compared with other samples like parents of children with type I diabetes or healthy children, or adult patients with osteosarcoma, parents of children with cancer present more PTG. Likewise, factors that influence the development of PTG, such as cultural context, cognitive processing, adjustment to the disease and certain personality traits are observed. The published clinical evidence endorses the existence of PTG in parents of children with cancer. However, it would be necessary to carry out further investigation, particularly subjective and longitudinal studies with larger homogeneous samples, in order to design interventions aimed at promoting PTG and avoid focusing solely on the negative aspects of oncological disease in children.

Managing Addiction: Guidelines for Patients With Cancer.

Addiction in patients with cancer is not well described. Patients with substance use disorders (SUDs) and cancer experience worse outcomes; however, no guidelines exist for identifying and successfully managing these issues in oncology. With the goal to improve patient safety and outcomes, an interprofessional work group at a major academic cancer hospital initiated a trial screening process for identifying substance abuse issues in an oncology population. Simultaneously, guidelines for patients with cancer and SUDs were created.

Gender medicine and oncology: report and consensus of an ESMO workshop.

The importance of sex and gender as modulators of disease biology and treatment outcomes is well known in other disciplines of medicine, such as cardiology, but remains an undervalued issue in oncology. Considering the increasing evidence for their relevance, European Society for Medical Oncology decided to address this topic and organized a multidisciplinary workshop in Lausanne, Switzerland, on 30 November and 1 December 2018. Twenty invited faculty members and 40 selected physicians/scientists participated. Relevant content was presented by faculty members on the basis of a literature review conducted by each speaker. Following a moderated consensus session, the final consensus statements are reported here. Clinically relevant sex differences include tumour biology, immune system activity, body composition and drug disposition and effects. The main differences between male and female cells are sex chromosomes and the level of sexual hormones they are exposed to. They influence both local and systemic determinants of carcinogenesis. Their effect on carcinogenesis in non-reproductive organs is largely unknown. Recent evidence also suggests differences in tumour biology and molecular markers. Regarding body composition, the difference in metabolically active, fat-free body mass is one of the most prominent: in a man and a woman of equal weight and height, it accounts for 80% of the man's and 65% of the woman's body mass, and is not taken into account in body-surface area based dosing of chemotherapy. Sex differences in cancer biology and treatment deserve more attention and systematic investigation. Interventional clinical trials evaluating sex-specific dosing regimens are necessary to improve the balance between efficacy and toxicity for drugs with significant pharmacokinetic differences. Especially in diseases or disease subgroups with significant differences in epidemiology or outcomes, men and women with non-sex-related cancers should be considered as biologically distinct groups of patients, for whom specific treatment approaches merit consideration.

Virtual clinical trials identify effective combination therapies in ovarian cancer

A major issue in oncology is the high failure rate of translating preclinical results in successful clinical trials. Using a virtual clinical trial simulations approach, we present a mathematical framework to estimate the added value of combinatorial treatments in ovarian cancer. This approach was applied to identify effective targeted therapies that can be combined with the platinum-taxane regimen and overcome platinum resistance in high-grade serous ovarian cancer. We modeled and evaluated the effectiveness of three drugs that target the main platinum resistance mechanisms, which have shown promising efficacy in vitro, in vivo, and early clinical trials. Our results show that drugs resensitizing chemoresistant cells are superior to those aimed at triggering apoptosis or increasing the bioavailability of platinum. Our results further show that the benefit of using biomarker stratification in clinical trials is dependent on the efficacy of the drug and tumor composition. The mathematical framework presented herein is suitable for systematically testing various drug combinations and clinical trial designs in solid cancers.

Ultrahypofractionation Should be a Standard of Care Option for Intermediate-Risk Prostate Cancer

Ultrahypofractionation Should be a Standard of Care Option for Intermediate-Risk Prostate Cancer

Low lean mass and chemotherapy toxicity risk in the elderly: the Fraction study protocol

BackgroundHalf of cancer cases occur in patients aged 70 and above. Majority of older patients are eligible for chemotherapy but evidence for treating this population is sparse and severe toxicities affect more than half of them. Determining prognostic biomarkers able to predict poor chemotherapy tolerance remains one of the major issues in geriatric oncology. Ageing is associated with body composition changes (increase of fat mass and loss of lean mass) independently of weight-loss. Previous studies suggest that body composition parameters (particularly muscle mass) may predict poor chemotherapy tolerance. However, studies specifically including older adults on this subject remain sparse and the majority of them study body composition based on computed tomography (CT) scanner (axial L3 section) muscle mass estimation. This method is to date not validated in elderly cancer patients.MethodsThis trial (Fraction) will evaluate the discriminative ability of appendicular lean mass measured by dual-energy X-ray absorptiometry (DXA) to predict severe toxicity incidence in older cancer-patients treated with first-line chemotherapy. DXA is considered the gold standard in body composition assessment in older adults.Patient’s aged ≥70 diagnosed with solid neoplasms or lymphomas at a locally advanced or metastatic stage treated for first-line chemotherapy were recruited. Patients completed a pre-chemotherapy assessment that recorded socio-demographics, tumor/treatment variables, laboratory test results, geriatric assessment variables (function, comorbidity, cognition, social support and nutritional status), oncological risk scores and body composition with DXA. Appendicular lean mass was standardized using evidence based international criteria. Participants underwent short follow-up geriatric assessments within the first 3 months, 6 months and a year after inclusion. Grade 3 to 5 chemotherapy-related toxicities, as defined by the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) were assessed at each chemotherapy cycle.DiscussionThe finding that body composition is associated with poor tolerance of chemotherapy could lead to consider these parameters as well as improve current decision-making algorithms when treating older adults.Trial registrationClinicalTrials.gov Identifier: NCT02806154 registered on October 2016.

Twelve tips for teaching oncology to non-oncologists

Background: Teaching subspecialty care to trainees who are not pursuing that subspecialty poses many challenges. These challenges are amplified in the teaching of oncology to non-oncologists because there are more new therapies emerging in oncology than in any other discipline, and there are few oncologic issues managed by generalists without consultation. Concurrently, there is an increasing need for generalists to manage many aspects of care for patients with cancer.Aim: To provide 12 tips for oncologists to use to educate trainees on their oncology rotations.Method: The tips provided are based upon the available literature and the authors’ own experience.Results: The 12 tips presented offer specific strategies for oncologists to enhance their teaching by selection of appropriate content and enhancing delivery. Focus is placed on aspects of oncology that trainees are likely to encounter as a generalist or non-cancer subspecialist. While oncology is used as the case study, these strategies are adaptable to any subspecialty area.Conclusion: Oncologists and other subspecialists can be core medical educators.