This systematic review was reported based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines [13]. The protocol was registered and published by PROSPERO (ID: CRD42022271308).

A search strategy was developed with the assistance of an information specialist using these and other related terms: “Residents or Fellows or Trainees or Medical Training” AND “Education or Training Programs” AND “Multidisciplinary” AND “Oncology.” The following databases were searched from inception: MEDLINE, MEDLINE In-Process, Embase Classic + Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and APA PsycINFO (all via the Ovid platform); and Education Resources Information Center via the EbscoHost platform. The search was initially performed on July 21, 2021, and updated twice (ie, on February 26, 2023, and October 9, 2024). Table S1 in Multimedia Appendix 1 shows the number of citations identified from each database. The search strategy and the number of citations identified via MEDLINE are included in Table S2 in Multimedia Appendix 1.

Eligibility criteria were developed prior to the search strategy. The scope of this study was to evaluate the multidisciplinary oncology education offered by residency and fellowship programs to postgraduate medical trainees. Thus, the first eligibility criterion was the inclusion of studies investigating postgraduate medical training (ie, interns, residents, and fellows). Studies about nonphysician specialties (eg, nursing, pharmacy, or dentistry), attending or staff physicians, or those involving solely Masters, PhD, or medical students were excluded. Studies were included if their focus was specific to oncology care. Selected studies focused on multidisciplinary aspects of medical education, which included knowledge of collaborating medical specialties and their roles in cancer care (eg, surgical trainees’ knowledge of radiation or medical treatments). Trainees from all specialties were included, as long as the study was assessing the multidisciplinary oncology education of trainees, and therefore, these were not necessarily restricted to oncology residency or fellowship programs (eg, medical oncology, radiation oncology, surgical oncology). Only primary research papers and studies available in English (ie, both original and translations to English) were included. Thus, all reviews, case studies, opinion papers, abstract-only papers, conference literature, and short reports were excluded.

There were 2 stages of review: title and abstract screening, followed by full-text screening. A total of 6 reviewers (HT, GK, CML, IB, ZF, and RV) were involved, and studies were screened by a minimum of 2 independent reviewers at each stage. Discrepancies were resolved by a third reviewer. Both screening stages were performed on Covidence [14], a web-based systematic review organization software.

Data extraction was performed on the selected studies. Studies were divided between 3 reviewers (HT, CML, and RV) who performed data extraction. Study design, study population, outcome measures, and main results were extracted from each study.

Selected studies were independently assessed for quality by 2 independent reviewers (CL, IB, and RV) using the Mixed Methods Appraisal Tool (MMAT) version 2018 [15]. Discrepancies were resolved through discussion with a third author (HT). The MMAT was chosen due to its ability to concomitantly assess multiple study types (ie, qualitative, quantitative randomized controlled trial, quantitative nonrandomized, quantitative descriptive, or mixed methods). Each study was evaluated on a set of 5 criteria depending on the study type. For survey studies, the risk of nonresponse bias was deemed to be high if the response rate was below 70%. Studies were assigned an overall quality score ranging from 0 to 5 stars based on the number of criteria that were met.

The search strategy resulted in a total of 6991 studies. After removing duplicates between databases, 5020 unique studies were identified. A total of 73 studies remained after title and abstract screening. Full-text screening excluded 49 studies, and 24 studies were therefore included in the final analysis. The PRISMA flow diagram is demonstrated in Figure 1.

The remaining 24 studies were divided into 2 categories. Fifteen studies assessed the quality of existing postgraduate oncology training based on trainees’ multidisciplinary knowledge. The remaining 9 assessed trainees’ multidisciplinary knowledge following an educational intervention. For the latter category, all studies with educational interventions directed toward improving multidisciplinary oncology knowledge and skills among interns, residents, and fellows were included. These included studies that are part of the formal postgraduate medical training (eg, residency or fellowship program), as well as external initiatives for improving multidisciplinary oncology training. Studies involving educational interventions for medical students and staff or attending physicians were not included.

A summary of the 15 studies evaluating the impact of existing multidisciplinary oncology training is included in Table 1. These studies included surgical or surgical oncology fields [16-23], hematology or medical or hematology oncology [16,20-22,24,25], geriatrics or geriatric oncology [20,22,26], radiation oncology [16,20,21,23,27], palliative medicine [16,20], radiology [21], pathology [21], genetics [23], dermatology [23], pediatric specialties [28], and other medical fields (eg, internal medicine, nephrology, neurology) [22,23].

Thirteen studies obtained opinions of trainees with respect to multidisciplinary oncology education within their training programs [16-25,27,28,30]. Morris et al [20] used a Delphi consensus process, and 4 studies directly interviewed trainees and faculty [21,24,28,29]. The remainder of the studies used surveys. Maggiore et al [26] surveyed geriatrics program directors, Givi et al [29] surveyed head and neck surgery program directors, and Akthar et al [16] surveyed program directors of pediatric and adult hematology oncology, surgical oncology, radiation oncology, and palliative medicine. Eid et al [24] used a combination of expert consultation, trainee interviews, review of trainee rotation evaluations, and literature review to assess their multidisciplinary educational needs.

While all studies analyzed the quality of existing multidisciplinary education, there were differences in the disciplines investigated across studies. Akthar et al [16], Delaye et al [22], Mäurer et al [23], Walraven et al [21], Picca and Reed [28], and Brenner and De Donno [17] focused on identifying broad gaps in multidisciplinary education including knowledge and skills of trainees in numerous fields, such as radiation, surgical, and medical oncology, radiology, pathology, geriatrics, palliative medicine, and other pediatric and medical fields. The remaining 8 studies focused on a more specific set of trainee skills. David et al [25], Eid et al [24], and Maggiore et al [26] assessed gaps in geriatric oncology education among hematology residents and fellows, hematology oncology fellows, and geriatrics fellows, respectively. Morris et al [20,27] assessed gaps in the radiation oncology training curriculum. Park et al [18] and Wilson et al [19] assessed the quality of general surgery residency training in breast cancer care. Le Nail and Samargandi [30] evaluated the quality of tumor boards for orthopedic oncology trainees. Finally, Givi et al [29] performed a needs assessment analysis of the head and neck surgery training curriculum.

13 studies assessed the strengths and weaknesses of oncology training programs [16-19,21-23,25-30]. Of these, 11 found that trainees had limited exposure to multidisciplinary oncology disciplines, barriers to attending multidisciplinary oncology meetings, and a low level of trainee comfort in multidisciplinary oncology knowledge [16-19,21-23,25-28]. Givi et al [29] found that 27% of interviewees indicated exposure to multidisciplinary care as a strength of the head and neck surgery training program, although 38% endorsed the need to improve fellows’ multidisciplinary participation. In general, Akthar et al [16] found the least amount of multidisciplinary training in geriatric oncology, compared to palliative medicine, medical, radiation, and surgical oncology. Similarly, Morris et al [27] found that less than 10% of radiation oncology trainees received geriatrics training. Furthermore, less than half of geriatrics fellows were offered geriatric oncology rotations [26]. For multidisciplinary breast cancer management, Park et al [18] found limited training in genetics, radiation oncology, and pathology among surgical residents, compared to rotations within surgery, radiology, and medical oncology. Brenner and De Donno [17] found that a small proportion of general surgery residents received training in the fields of radiation (23%) and medical oncology (31%), but over half (53%) received exposure to palliative care.

Additionally, 11 studies researched areas of improvement for multidisciplinary oncology education among the postgraduate programs via surveys, interviews, Delphi consensus, and literature search [17,20,21,23-30]. Maggiore et al [26] and Morris et al [27] found that 77% of geriatrics fellows and 85.3% of radiation oncology residents advocated for further geriatric oncology training. David et al [25] found that over 95% of hematology trainees endorsed geriatric training during residency. 82% of general surgery residents surveyed by Brenner and De Donno [17] agreed that additional multidisciplinary training is needed to optimize cancer care. Additionally, based on an educational needs assessment, Eid et al [24] found that the top 3 priorities for a geriatric oncology program included geriatric assessment, pharmacology, and psychosocial skills. MTBMs were found to enhance trainee experience and multidisciplinary oncology education [21,28,30]. However, some barriers to attending meetings included time constraints, clinical duties, and lack of active resident participation [21,28,30]. Residents and specialists interviewed by Walraven et al [21] suggested that the educational value of multidisciplinary team meetings could be improved through additional training such as multidisciplinary team meeting simulations and courses on effective communication and meeting skills.

A summary of the 9 studies analyzing the impact of educational interventions is included in Table 2. The majority included general surgery trainees [31-35]. Faculty and trainees from radiation oncology [32,35], medical oncology [12,35], respirology [12,36], thoracic surgery [12], gynecology [35], urology [37], and palliative medicine [38] were also included. All 9 studies demonstrated improvements in multidisciplinary oncology knowledge and skills postintervention.

The study by Cook et al [31] compared the impact of a multidisciplinary breast rotation to traditional oncology or community rotations using trainee self-evaluations. Martin et al [38] and Mattes et al [12] analyzed the effectiveness of didactic learning for palliative radiotherapy and lung cancer radiotherapy, respectively, using pre- and postcourse trainee evaluations. Meani et al [35] studied the impact of a multidisciplinary breast cancer course on the knowledge and practice of faculty and trainees using a questionnaire. Three studies by Sloan et al tested the quality of case-based instruction, involving workshops or Objective Structured Clinical Examination (OSCE) stations, where evaluations were completed by trainees, standardized patients, and faculty [32-34]. In the 2004 study by Sloan et al [34], faculty and standardized patient completed evaluations following the observation of trainees in OSCE stations. Patient ratings mainly included interpersonal skills, while faculty ratings included both the clinical and interpersonal skills of trainees. In the other 2 Sloan et al studies, faculty and standardized patients provided feedback on the overall quality of workshops, rather than a specific focus on trainee skills [32,33]. Many of the standardized patients were actual patients with cancer [32-34]. Two of the Sloan et al studies with breast cancer-specific stations focused on knowledge and skills in the following fields: surgical, medical, and radiation oncology; pathology; plastic surgery; and radiology [32,34]. A pilot study by the same group included a head and neck workshop in which stations were designed by faculty from general surgery, radiation oncology, cardiothoracic surgery, otolaryngology, plastic surgery, pathology, anesthesiology, speech pathology, and dentistry [33].

In 8 of these 9 studies, the benefit of educational interventions was noted by the trainees through self-assessment of knowledge or skills [12,31-33,35-38], while Sloan et al [34] demonstrated improvements in knowledge or skills, as assessed by faculty and patients following the observation of trainees in OSCE stations. In addition to reporting subjective benefits, Khoshgoftar et al [37], Mattes et al [12], and Martin et al [38] used objective assessments to demonstrate improvements in trainee knowledge postintervention. Interestingly, Sloan et al [34] showed that while the intervention benefited residents’ knowledge and skill set in breast cancer management both immediately after and 8 months postintervention, it declined after 8 months. In the other 2 studies by this group [32,33], trainees, faculty, and patients rated the interventions highly.

A summary of the MMAT quality assessment is included in Table S3 in Multimedia Appendix 1. Five studies were categorized as nonrandomized, 4 as qualitative, 13 as quantitative descriptive, 1 as mixed methods, and 1 as randomized controlled. Studies were given a score out of 5, based on the number of MMAT criteria met. Two studies were given an overall MMAT quality rating of 3 stars, 14 studies were rated as 4 stars, and the remaining 8 were rated as 5 stars. Overall, all studies were deemed to be satisfactory by authors, based on MMAT quality assessment criteria.

To our knowledge, this is the first systematic review of multidisciplinary oncology education in postgraduate medical training. These data summarize educational gaps and potential solutions to improve multidisciplinary education for future trainees. Of the 24 studies included in the final analysis, 15 obtained faculties’ and trainees’ opinions on deficiencies and areas of improvement for existing multidisciplinary oncology education [16-19,24,26,27]. They generally reported limited multidisciplinary oncology training or knowledge, barriers to multidisciplinary training, and advocated for further instruction in different areas. The remaining 9 studies studied the impact of educational interventions on trainees’ oncology expertise [31-34,38]. Multidisciplinary rotations, tumor board meetings, didactic teaching, and case-based learning were found to be beneficial based on trainee self-assessments, written exams, and evaluations from faculty and patients following the observation of trainees in OSCE stations.

Filling the current gaps in multidisciplinary oncology education using the aforementioned educational interventions has the potential to improve multidisciplinary communication, appropriate referrals, and oncologic outcomes [3-5]. Studies by Mattes et al [12] and Martin et al [38] found that trainees were more likely to collaborate and make appropriate referrals to radiation oncologists after didactic teachings in lung cancer treatment and palliative radiotherapy, respectively. Several studies also found MTBMs to enhance trainee education [30,36,37]. In fact, the study by Mackay et al [36] found that tumor board simulation sessions significantly improved trainee’s confidence in presenting in tumor board sessions. After all, improved communication and referral patterns are central to effective multidisciplinary collaboration among oncology specialists and ultimately improve the access of patients to evidence-based oncologic treatments.

Geriatric oncology was consistently found to be an area in which trainees received limited training [16,26,27,39]. As cancer incidence increases in older adults, a population with a higher burden of comorbidities, trainees must gain sufficient knowledge and experience in geriatric oncology to optimize treatment [40]. These findings are echoed in a review by Morris et al [39] highlighting insufficient training and education in geriatric oncology among radiation oncology trainees across several different countries. This training should identify the specific needs of older patients and thereby result in a more informed and nuanced approach to this population’s medical and psychosocial issues [24]. Development of these skills may be achieved through dedicated rotations or training in geriatric oncology.

Based on findings from this study, it is evident that the quality of multidisciplinary oncology education and training needs to be assessed and addressed. Implementation of benchmarks to ensure sufficient training across residency and fellowship programs commonly involved in cancer care would provide an educational quality metric [6-10]. This would encourage training programs to develop and establish multidisciplinary oncology curricula. One approach to achieve this would be to ensure trainee participation in a variety of educational activities such as multidisciplinary case conferences, research, rotations, didactic teaching, and case-based learning led by faculty from other disciplines [11,31-34,38]. Furthermore, a review of each residency or fellowship program’s curriculum by a multidisciplinary faculty committee may ensure sufficient trainee exposure to collaborating oncology areas.

Competency-based medical education is an outcome-based approach to evaluate medical trainees and ensure a high degree of graduate skill set [41]. This is often done via objective measures, such as entrustable professional activities (EPAs) and milestones. The development of standardized and program-specific EPAs, specifically for multidisciplinary oncology education, would provide training programs with a specific measure of their trainees’ knowledge, skills, and progress in this area. Using EPAs would also identify areas of improvement for trainees early on in their training and would allow for additional support to improve multidisciplinary oncology competencies. Ultimately, these EPAs should mirror curriculum changes to ensure effective multidisciplinary oncology education. The benefits of using EPAs for geriatric oncology training are echoed by Eid et al [24]. They provide an example of an EPA to assess the appropriateness of chemotherapy for a geriatric patient, which includes the ability to perform a comprehensive geriatric assessment, having sufficient knowledge of chemotherapy toxicities and interactions, and assessment of suitability based on patients’ comorbidities. This represents a geriatric oncology-specific EPA for medical or hematology oncology trainees. Oncology training programs may adopt similar EPAs to ensure a high quality of multidisciplinary oncology training within their residency and fellowship programs.

Despite its merits, there are potential barriers to the implementation of oncology training curricula. Several factors may prevent trainee participation in multidisciplinary education activities, including limited elective time, educational options, or available personnel. For instance, those training in the community or rural hospitals may not have access to many electives in other oncology fields. For the same reason, there may be limited available multidisciplinary faculty to either design effective oncology curricula or mentor trainees. Furthermore, many residency or fellowship programs may have strict curricula and elective requirements, and thus limit elective options for trainees. To overcome some of these challenges, studies have suggested the importance of web-based courses or teaching sessions to supplement their curriculum. As a result of the COVID-19 pandemic, web-based education has become an integral part of medical training that will likely remain used to various degrees in the future [42,43]. Data supports the effectiveness of web-based training, including web-based rotations or clinical training [44-46], tumor board meetings [28,37], surgical skills training [47], and didactic and case-based teaching [48-52].

Furthermore, local, state-wide or provincial, and national resources and programs could also be offered to trainees interested in further advancing their multidisciplinary oncology knowledge and skills outside their residency and fellowship programs. Certainly, didactic teaching [12,35,38], as well as workshops and OSCE-style evaluation sessions [32-34] are valuable in advancing trainee education in multidisciplinary oncology care. Depending on the topic, these teaching sessions could be offered in person, remotely via web-based applications, or as a prerecording to enhance trainee participation. As indicated by Mackay et al [36], tumor board simulation sessions contribute to significant improvements in trainee confidence and skills in participating in tumor boards. This is a novel educational intervention not traditionally offered by residency or fellowship programs. The addition of such resources and programs outside of the mainstream postgraduate training programs has the potential to supplement trainee education toward multidisciplinary oncology care.

Given the time constraint of residency and fellowship, it is not feasible for trainees to gain all relevant multidisciplinary knowledge and skills while also excelling in all core competencies relevant to their program. Every proposed intervention will have its own challenges to implement and needs to be balanced against other rotations within the curriculum. Yet, it is preferred that trainees obtain sufficient multidisciplinary knowledge during training rather than through experience during practice. It is crucial that training programs conduct an evaluation of any new educational intervention and prioritize selected interventions in their curricula based on outcomes and feedback.

This study has limitations. Only 24 studies have analyzed the quality of multidisciplinary oncology education among postgraduate medical trainees. Furthermore, we limited our study to English-only and primary papers. It is possible that additional studies analyzing multidisciplinary oncology education in other languages or papers (eg, grey literature) exist that are missing from our results. Over a third of these studies were also published more than 5 years ago. Particularly, 3 of the intervention studies are by Sloan et al [32-34], published in 1997, 1999, and 2004, which could have had overlapping participants. This could limit the generalizability of the findings from these studies. There is a need for additional and more contemporary research assessing the needs of postgraduate medical trainees and the impact of newer educational interventions. It is particularly important to evaluate the use of technologies currently used in medical education such as web-based live teaching [43-47], clinical teaching tools such as case-based modules with built-in radiology software [53,54], and virtual reality surgical training [55-57]. Additionally, none of the studies on educational interventions were conducted with trainees in geriatric oncology. As previously discussed, this is an important aspect of oncology, though generally missing from oncology training curriculums. Thus, additional studies are needed within these fields. Furthermore, while a large proportion of studies solely focus on gaps in geriatric oncology education, this may not be generalizable to all multidisciplinary oncology education needs. Future research will be important in developing multidisciplinary oncology curricula for postgraduate trainees.

This systematic review demonstrated several gaps in the existing multidisciplinary oncology training of postgraduate medical trainees and the promising results of various educational interventions in bridging these gaps. Further studies investigating the needs of trainees at both local and national levels are needed to develop specific educational curricula and program requirements that focus on multidisciplinary oncology collaboration. Future research should also assess contemporary educational interventions to determine the most effective methods of attaining multidisciplinary oncology expertise among postgraduate medical trainees.