3.1 Study selection

Three of the main electronic bibliographic databases, namely Embase, Scopus and PubMed, have been selected to identify studies for the systematic review. The search retrieved 706 articles, that after deduplication became 618. Following the screening inclusion and exclusion criteria, 276 articles were included in full-text review, and finally 49 have been included in this work. The details of each step are described in Fig. 4. Out of the 49 included studies, 31 publications are quantitative randomized control trials, 9 quantitative non-randomized studies (case-studies, cohort studies), 4 quantitative descriptive studies (cross-sectional surveys), 3 qualitative studies (interviews) and 2 mixed-methods studies (quantitative non-randomized trials and qualitative studies).

Fig. 4

PRISMA flowchart of studies selection

3.2 Answer to RQ1. The studies proposing digital solutions are more prevalent in the Netherlands and in Germany, and breast cancer patients are the most targeted by single-cancer type interventions.

The 49 included studies were published between 2014 and 2024, with over \(81\text\) of the studies published since 2017. Across all studies, the number of participants ranged between 2 to 630, with a median of 130 individuals. Table 6 provides a summary of the included studies. The distribution of academic publications across the EU countries shows a prevalence of studies conducted in the Netherlands (\(=19;38\text\)) and Germany (\(=15;30\text\)), while the remaining in Spain (\(n=6;12\text\)), Italy (\(n=3;6\text\)), France (\(n=2\);\(4\text)\), Sweden (\(n=2\);\(4\text)\), Portugal \(\left(n=2;4\text\right)\), Denmark (\(n=1\);\(2\text)\), and Austria (\(n=1\);\(2\text)\). Moreover, the authors’ nationalities in 96% of the cases corresponded to the country in which the studies have been conducted, highlighting the absence of transnational studies on the impact of digital interventions. Notably, the number of studies across the different countries reflects the rate of cancer incidence (the countries that contributed the most publications on this topic are also the ones most impacted by this illness) [1].

Nearly half of the studies included encompassed participants with heterogeneous types of cancer \((n=23;48\text)\), followed by breast cancer (\(n=14;29\text\)), colorectal cancer (\(n=5;10\text\)), head and neck tumor (\(n=2;4\text\)), and the remaining by gynecologic, esophagus, prostate, lung (each corresponding to n = 1; 2%). The high prevalence of breast cancer studies, in alignment with the literature [18], could be related to the incidence rate and the potential for early detection and intervention, and to the high survival rates.

3.3 Answer to RQ2. The key areas of interventions for e-health solutions are i) psychophysical well-being, ii) management of physical distress iii) remote monitoring of vitals and symptoms, and iv) empowerment and self-efficacy.

The studies included in this review proposed various types of digital intervention. We clustered these interventions in 4 different thematic areas on the basis of the predominant scope of the digital solutions as follows: a) supporting the psychophysical well-being [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33], b) reducing the physical distress [20, 26, 34,35,36,37,38,39,40,41], c) remote monitoring of vitals and symptoms [42,43,44,45,46,47,48,49,50,51,52,53], and d) empowerment and self-efficacy towards patient-centric care [54,55,56,57,58,59,60,61,62,63,64,65].

Emotional stress can exacerbate physical symptoms and affect the overall quality-of-life of cancer patients and their caregivers. E-health solutions, such as mobile applications offering mindfulness exercises, virtual therapy sessions, and online support communities, potentially provide accessible and tailored mental health resources that are available every day and in every moment of the day.

The management of physical distress is another critical area addressed by e-health interventions for oncological patients. Online exercise applications, dietary management platforms, and wearable devices for some specific issues like alopecia enable patients to embrace a healthier lifestyle, and help them maintain it over a longer period.

Remote monitoring of vitals and symptoms is a key component of e-health solutions, offering a proactive approach to patient care. Mobile health apps and web-based interventions allow patients to autonomous log their symptoms in real-time and receive timely medical guidance. The ability to oversee patients' conditions without requiring frequent hospital visits not only reduces the burden on caregivers and healthcare facilities but also minimizes patient exposure to hospital environments, which is particularly beneficial for immunocompromised individuals.

Enhancing empowerment and self-efficacy can improve the attitude of patients and their caregivers in the difficult moment of cancer treatment and beyond. E-health solutions in this area can include educational resources, interactive platforms, and decision-aid tools that encourage patients to actively participate in their health care by tracking progress, exchanging experiences and advice, and making informed decisions. This empowerment leads to a better adherence to treatment regimens and proactive health behaviors, which are associated with improved health outcomes.

3.4 Answer to RQ3: the effectiveness of digital solutions is typically higher than traditional healthcare, especially those focusing on psychosocial well-being.

Here we report the results in terms of effectiveness of the digital health solutions identified in this systematic literature review clustered by the thematic areas identified in Section 3.3.

3.4.1 Digital interventions for improving psychophysical well-being

Study [19] showed the effectiveness of electronic mindfulness behavioral cognitive therapy (eMBCT) in reducing psychological distress compared to traditional MBCT. Willems et al. [20] proved a positive impact on emotional and social functioning, and showed a decrease in depression and fatigue 6 months after baseline, which remained significant also when considering effect size. Dozeman et al. [21] proved that a guided web-based cognitive therapy for insomnia (I-CBT) in breast cancer patients is feasible and effective for younger breast cancer patients and those with severe insomnia. Luigjes-Huizer et al. [22] showed how an e-health program and video calling sessions with a mental health worker improve the general mental well-being and fear of cancer recurrence (FCR) severity, with the effectiveness of the intervention remaining at 10-month follow-up. The outcomes across different studies, however, are mixed, as no effect of CBT-based online self-help training on FCR has been found in [23].

The digital therapeutic MIKA app, based on holistic and personalized approach, demonstrated efficacy in reducing depression and fatigue by 42% and by 23.1%, respectively, with respect to the control group [24]. The web-based intervention MyCourse-Quit smoking, based on CBT, acceptance and commitment therapy and motivational interviewing techniques, proved to be more effective in reducing the daily consumption of cigarettes compared to control group in cancer survivors [25]. The internet-based tailored rehabilitation exercise program e-CUIDATE improved functional capacity in terms of distance covered in the 6-min test, and cognition in terms of memory in cancer survivors [26, 27]. The Danish smartphone app, Kræftværket, includes a tracking module for symptoms and activities, an information bank with text and video material, and a social community platform that facilitates networking and sharing experiences; it showed improvement in QoL scales for young adults in treatment, and in physical, cognitive, and social functions for follow-up group [28]. Comparing face-to-face and online psychotherapy or support groups for cancer survivors showed no significant difference, thereby suggesting the potential of online interventions to overcome geographical barriers [30, 31]. Martín-Payo et al. [32] demonstrated how a web-app based on Behavior Change Wheel Model improved adherence to healthy behaviors, and significantly facilitated the identification of risk factors and symptoms in the intervention group of breast cancer patients.

Two studies also focused on informal caregivers [29, 33]: the first German app to address informal caregivers needs has been the PartnerCare app [29], which showed positive effects on psychological distress and anxiety within the intervention group via psychoeducation, behavioral therapy, supportive therapy, and guided imagery. A second study focused instead on the German online support group (OSG), which is a forum for counselling, dissemination, and treatment between prostate cancer patients and informal caregivers. Namely, Ihrig et al. [33] have found OSG to be beneficial in terms of psychological burden for informal caregivers of cancer patients.

3.4.2 Digital interventions for managing physical distress

An app for patient education, improving compliance and discomfort levels for colonoscopy preparation has been introduced in [34], showing positive effects in all the measured outcomes. The digital scalp cooling technique effectively prevented chemotherapy-induced alopecia, thereby enhancing psychological well-being in cancer patients [35]. The web-based intervention Cancer Aftercare Guide (KNW) is a computer-tailored intervention that aims to increase survivors’ quality-of-life with 8 modules that target physical activity, diet, smoking cessation, return-to-work, fatigue, anxiety and depression, social relationships, and residual problems [20, 36,37,38,39]. It was shown to improve social functioning, reduce depression and fatigue at 6 months, and increase moderate physical activity of cancer survivors younger than 57 years-old. However, it failed to foster vegetable consumption, cessate smoking, enhance emotional/social functioning, and reduce depression and fatigue after 12 months.

According to [40], home-based online training with video presentations for post-surgical cancer patients are effective in enhancing oxygen uptake and decreasing myocardial workload during exercise. Lozano-Lozano et al. [41] developed the app BENECA (Energy Balance on Cancer) to stimulate changes in breast cancer survivors’ lifestyles. BENECA monitored the energy expenditure and energy intake of breast cancer survivors and provided instantaneous feedback on the users’ energy; the outcome was an improved QoL, PA motivation, and reduced body weight, with high adoption and satisfaction rates among the participants. Galiano-Castillo et al. [26] also focused on lifestyle in breast cancer patients, showing how an internet-based exercise intervention yielded significant improvements in quality-of-life, muscle strength, fatigue, physical and cognitive functioning, and arm symptoms. Such an improvement remained after 6 months.

3.4.3 Digital interventions for remote monitoring

Sprave et al. [42] demonstrated the feasibility of integrating app-based electronic patient-reported outcomes (ePRO) in patients with head and neck cancer (HNC) undergoing radiotherapy, increasing reporting of cancer-specific burden and improved patient satisfaction. Graf et al. [43] also reported an improved acceptance and evaluation of a tablet-based ePRO app when compared to paper-based PRO, with patients finding ePRO assessment less stressful and difficult. Asensio-Cuesta et al. [44] found the Lalaby app, which monitors quality-of-life of lung cancer patients through sensors and questionnaires in real-time, effective towards better therapeutic decisions. The use of ePRO apps can be however hindered by limited health literacy: Haudel et al. [53] showed how having an account on an online portal for ePRO (a proxy for health literacy) is strongly related to lower overall survival rate. In an effort to enhance health literacy, Sundberg et al. [50] supported the use of an interactive app for prostate cancer symptom management during radiotherapy.

E-health solutions can also be devised to enhance the quality of the information provided by adolescent cancer patients to clinicians: Lawitschka et al. [45] showed how the web-based gamified mobile app INTERACCT (Integrating Entertainment and Reaction Assessment into Child Cancer Therapy) enables adolescent cancer patients to self-track in real-time symptoms improving quality of medical information for clinicians compared to traditional methods.

Digital solutions have also been implemented to monitor health-related quality-of-life (HRQoL). Adriaans et al. [46] tested an online platform, the KLIK portal, to monitor HRQoL by using patient reported outcome measures (PROMs), without showing any significant effects on patient satisfaction, and HRQoL. Brusniak et al. [47] evaluated HRQoL in metastatic breast cancer patients using digital monitoring, to include patients not living in close proximity to the care center. Beutter et al. [