Advancements in diagnostic and treatment strategies have led to substantial improvements in treatment prognoses for children with cancer. The 5-year survival rate of childhood cancers has increased dramatically in high-resource settings, from <50% in the 1970s to >80% in the past decade.1 Consequently, there has been a global surge in the population of survivors of childhood cancer, especially in developed regions such as Hong Kong. According to the Hospital Authority Cancer Registry, from 2001 to 2017 in Hong Kong, approximately 180 paediatric patients <19 years of age were diagnosed with cancer each year.2 It is unquestionably necessary to further improve survival rates, and recent efforts and resources have been dedicated to improving the quality of life and health outcomes of survivors of childhood cancer in Hong Kong.3 4 5

Cancer survivors are susceptible to developing a spectrum of late effects because of their previous treatment exposures.6 7 Studies have shown that histories of specific treatment exposures, coupled with continued engagement in health-damaging behaviours during survivorship, may accelerate or exacerbate the development of late effects.8 9 The Children’s Oncology Group (COG)10 provide details of common health-damaging behaviours and their potential impacts on various treatment-related chronic conditions.

Adult and paediatric oncology research has suggested that cancer survivors and their families are often highly receptive to education regarding optimal lifestyles during the early survivorship period.11 Thus, the COG and other international oncology groups have specified that an ideal cancer survivorship programme should comprise recommended screening/surveillance protocols to detect recurrence and late effects, health promotion activities, specialty referrals, and psychosocial interventions.7 12 One systematic review reported that a comprehensive cancer survivorship care programme is associated with positive behavioural change and better health outcomes in survivors.3

In Hong Kong, a recent study by Chan et al13 showed that, although the rates of smoking and alcohol consumption were low among local survivors of childhood cancer, survivors were less likely than their healthy siblings to participate in cancer screening. However, the study did not examine frequencies of engagement in other health-protective behaviours, such as participation in physical activity, undergoing immunisation, using sunscreen, and consuming a balanced diet. Furthermore, survivors’ expectations of a comprehensive survivorship programme have not been investigated. The identification of predictors of poor health-behaviour practices and elucidation of survivors’ needs will presumably assist clinicians in developing targeted interventions to address the needs of this special population.

The primary aim of this study was to identify factors associated with engagement in health-protective and health-damaging behaviours among local survivors of childhood cancer. The secondary aim was to examine cancer survivors’ expectations of a comprehensive survivorship programme in Hong Kong.

This prospective, observational study was conducted at the paediatric oncology/haematology long-term follow-up clinic of the Prince of Wales Hospital, Hong Kong. Eligible participants were recruited through convenience sampling. Between June 2019 and March 2020, the study investigators obtained the list of patients who were scheduled to attend follow-up consultations at the long-term follow-up clinic; this clinic was typically held once per week. Patients were then screened for eligibility using the in-house electronic patient record system (Clinical Management System). All eligible patients who subsequently attended the long-term follow-up clinic were invited to participate in the study.

The inclusion criteria were as follows: diagnosis with primary cancer before 18 years of age; treatment in any medical institutions in Hong Kong; survival for at least 2 years since the completion of cancer treatment or 5 years since diagnosis; and ability to communicate in Cantonese. A parent was recruited if the survivor was aged ≤16 years, or if the survivor was cognitively impaired. Patients were excluded if they were diagnosed with non-cancer conditions (eg, aplastic anaemia, thalassemia), did not understand Cantonese, were still on active treatment, or had incomplete treatment data.

Clinical data regarding cancer diagnosis, treatment history, commodities, and relapse status were retrieved from survivors’ electronic health records. A 20-minute structured questionnaire was interviewer-administered. Participants self-reported their socioeconomic information (ie, highest education attainment, medical insurance, and monthly family income).

Health behaviours were measured using a version of the 2013 National Youth Risk Behaviour Survey14 that had been modified and translated into Traditional Chinese. To adapt the survey for use within the study population, questions pertaining to the healthy behaviour practices of young adult cancer survivors were added. These additional questions were developed based on the health behaviours and practices most frequently reported in studies of survivors of childhood cancer in other countries.9 15 16 Health-protective behaviours refer to engagement in physical activity, balanced diet, sun protection, and immunisation programmes. Health-damaging practices refer to alcohol consumption, smoking, and exposure to second-hand smoke. Alcohol consumption and smoking practices were evaluated in adult survivors only, as the legal age for purchasing tobacco and alcoholic products is 18 years in Hong Kong.

Participants were asked to rate the perceived values of recommended components of a comprehensive survivorship programme12 in the categories of health, psychosocial, parenting, and financial issues. Ratings were conducted using a 5-point Likert scale (1=least important, 5=most important). Participants were also asked to report their preferred time of enrolment into a survivorship programme and modes of services.

The current analysis is part of a broader study17 that aimed to evaluate the effect of an educational intervention on improving awareness of personal health risks among survivors (primary outcome), as well as general health literacy and health behaviours among survivors (auxiliary outcomes). The tailored educational intervention included a review of the survivor’s cancer treatment summary and teaching materials that contained simplified health promotion messages derived from the COG Health Links.10 Sample size was determined based on the primary outcome (awareness of personal health risks). A similar study by Landier et al18 showed that the proportion of survivors of childhood cancer who adequately understood their health risks (defined as awareness of >75% of treatment-related late effects for which they were at risk) was approximately 55% after two sessions of the tailored intervention (ie, θ=0.55). At α=0.05, the required sample size for achieving 80% power to detect a difference in proportion (target θ₀=0.45) between pre- and post-intervention assessments was 195. The current analysis reported the health behavioural practices of participants who provided baseline, pre-intervention assessments.

The SAS University Edition (version 2015; SAS Institute Inc, Cary [NC], US) software was used for all statistical analyses. Descriptive statistics were used to summarise participants’ demographics, clinical characteristics, and frequencies of health behaviours. Multivariable logistic regression analysis was conducted to identify factors that were associated with health behaviours. Associations were presented using odds ratios (ORs) and 95% confidence intervals (95% CIs). Based on a literature review,9 15 19 20 the hypothesised predictors comprised demographics and clinical characteristics (sex, age, cancer diagnosis, and time since diagnosis), as well as socioeconomic status (medical insurance status, monthly household income, and highest education attainment [in adult survivors only]). Finally, descriptive statistics were used to summarise participants’ preferences for the components of a comprehensive survivorship programme.

In total, 252 survivors were screened for eligibility; 39 were excluded for <2 years since treatment or <5 years since diagnosis, the presence of non-cancer diagnoses (eg, benign ovarian teratoma), inability to understand Chinese, or treatment performed outside of Hong Kong. Subsequently, 213 eligible participants were approached. Eight survivors declined to participate, while the remaining 205 eligible survivors provided informed consent and completed the study. Five participants were subsequently excluded because of incomplete treatment records. Finally, data from 200 participants were analysed (response rate 93.9%) [Fig 1].

The mean (± standard deviation) ages at interview were 26.9 ± 6.4 years and 11.1 ± 3.6 years among adult and paediatric survivors, respectively (Table 1). The mean age at cancer diagnosis was 7.3 ± 5.2 years. The mean time since treatment completion was 13.4 ± 7.6 years; 41.0% (n=82) of survivors were within 10 years after treatment. The most common diagnoses were leukaemia (n=78, 39.0%), lymphoma (n=28, 14.0%), and bone tumour (n=18, 9.0%). In total, 185 survivors (92.5%) had undergone chemotherapy, 130 survivors (65.0%) had received radiation, and 85 survivors (42.5%) had undergone surgery. Only 30 survivors (15.0%) had received hematopoietic stem cell transplantation.

All paediatric survivors were students. Among adult survivors, 107 (69.0%) had completed post-secondary education. Only 32 survivors (16.0%) reported a monthly household income of less than HKD$15 000, and 86 survivors (43.0%) had private medical insurance.

Interviews for paediatric survivors (n=45) were completed by parents (Table 1). The mean age of parents was 43.4 ± 7.7 years, and 43 (95.6%) parents had completed secondary school or higher education.

The health-protective and health-damaging behaviours of survivors are summarised in Table 2. The least frequently practised health-protective health-protective behaviour was physical activity. Only 16 survivors (8%) met the World Health Organisation recommendation of engagement in 20 minutes of aerobic physical activity for ≥4 days per week. Of the survivors, 104 (52.0%) reported that they exercised rarely (≤1 day per week) and 135 (67.5%) applied sunscreen rarely. Fewer than 40% of survivors “always” and “frequently” had a balanced diet. In terms of immunisation practice, 49 (24.5%) survivors reported that they did not undergo any immunisation and 37 (18.5%) were unsure about their immunisation history.

Among 155 adult survivors, 110 (71.0%) were never-drinkers, whereas 45 (29.0%) identified themselves as social drinkers. These social drinkers met the “moderate” and “low-risk” drinker definitions established by the National Institute on Alcohol Abuse and Alcoholism.21 Of the 155 adult survivors, 144 (92.9%) were never-smokers and three (1.9%) were ever-smokers. Only eight survivors (5.2%) were current smokers; they smoked a median of 7.5 cigarettes per day (interquartile range=5-10). Of the survivors, 85 (42.5%) were exposed to second-hand smoke; 41 (20.5%) from family members and 29 (14.5%) from colleagues.

Compared with survivors of central nervous system (CNS) tumours, survivors who had been diagnosed with haematological malignancies were more likely to adopt a balanced diet (OR=2.45; 95% CI=1.29-4.68). Younger age at interview was also a significant predictor of adoption of a balanced diet (OR=0.95; 95% CI=0.91-0.99) [Table 3].

Female survivors had more than fivefold greater odds of regular sunscreen use, compared with male survivors (OR=5.66; 95% CI=2.40-13.34). Lower education level in adult survivors (OR=0.20; 95% CI=0.05-0.83) and lower monthly household income (OR=0.35; 95% CI=0.15-0.84) were associated with inadequate sun protection (Table 3).

Older survivors were less likely than younger survivors to participate in immunisation programmes (OR=0.76; 95% CI=0.53-0.97). Although the difference was not statistically significant (P=0.051), immunisation practices tended to be less common in survivors who did not have private medical insurance, compared with survivors who did (OR=0.78; 95% CI=0.45-1.06).

In terms of health-damaging behaviours (Table 4), compared with survivors who had completed education to a higher level than secondary school, adult survivors with a lower education level had greater odds of being current or ever-smokers (OR=5.13; 95% CI=1.48-17.75) and of being exposed to second-hand smoke (OR=3.52; 95% CI=1.42-8.69).

Nearly all participants stated that the provision of survivorship education (n=168, 84%) and late-effects screening services (n=157, 78.5%) would be the most important components of a survivorship programme (Fig 2). Moreover, helping survivors to understand and confront the fear of relapse (n=161, 80.5%) and addressing psychological distress (n=154, 77%) were the most popular psychosocial services. Among parents (n=45), learning how to parent a child with cancer (n=36, 80%) and psychosocial support for parents (n=33, 73.3%) were regarded as essential components.

Most participants (n=81, 40.5%) stated that their preferred enrolment time into a survivorship programme would be at the initiation of cancer treatment; some participants (n=58, 29.0%) stated that their preferred enrolment time would be during the transition from active treatment to follow-up (Table 5). In terms of modes of services, most respondents preferred dialogue sessions with healthcare professionals (n=156, 78.0%), interactive platforms (n=100, 50.0%), and support groups (n=101, 50.5%) [Table 5].

There is growing evidence that physical activity is a therapeutic strategy that may reduce the risks of systemic recurrence and mortality in cancer survivors.22 Similar to findings from other countries, we found that physical inactivity was highly prevalent among survivors of childhood cancer.9 23 This observation was not surprising, considering that the rate of physical activity is low among the general population in Hong Kong; only 40% to 46% of children and youth met physical activity guidelines for a mean duration of 60 minutes of moderate-to-vigorous physical activity per day.24 Although we did not identify any significant predictors of physical inactivity, this large proportion of inactive survivors indicates the need to further explore the reasons for this phenomenon and devise interventions to address them. For example, interventions targeting the survivor–parent dyad may promote common lifestyle behaviours within the families of survivors.25 Moreover, local adventure-based training and experiential learning programmes may enhance self-efficacy in survivors, thereby empowering them to initiate and maintain a physically active lifestyle.26 27

Our study found that only 38% of survivors reported frequently consuming a balanced diet. For example, survivors of CNS tumours were more likely to have poor dietary habits, compared with survivors of non-CNS malignancies. This is concerning because patients with CNS tumours are more vulnerable to developing metabolic syndromes related to complications associated with cranial radiation and neurosurgery. Poor dietary habits may further exacerbate the disease course of these late effects.28 This finding suggests that dietitians should give advice regarding stricter dietary control to optimise the health of CNS cancer survivors in Hong Kong.

Despite the extensive promotion of the seasonal influenza vaccination programme by the Hong Kong Special Administrative Region Government,29 only 30% of survivors indicated that they had received the influenza vaccine in the past year. Younger survivors were more likely to have participated in vaccination programmes, probably because school-age children are generally enrolled into the government immunisation programme that provides the hepatitis B, pneumococcal, and annual influenza vaccines, as well as the recently added human papillomavirus (HPV) vaccine.30 We acknowledge that our findings must be interpreted with caution because survivors might inaccurately recall or report their vaccination histories. However, these results have two important implications that warrant attention from the medical community. First, there is a need to educate survivors regarding the role of vaccination in preventing severe complications from infection (eg, influenza and pneumococcal vaccines for preventing seasonal flu and pneumonia, respectively) and other malignancies (eg, HPV vaccine for preventing cervical cancer). In particular, collaborations among schools and community physicians may help promote the uptake of HPV vaccines among adolescent female survivors.31 32 Second, children treated with chemotherapy for childhood malignancies reportedly may develop acquired immunological defects in both cell-mediated and humoral immunity, resulting in the loss of protection conferred by prior vaccinations.33 Future work should involve the development of clinical consensus guidelines regarding vaccination administration schedules for non-transplant survivors of childhood cancer, particularly survivors who have received intensive chemotherapy treatment.

Similar to the findings of Chan et al,13 we found that health-damaging practices are uncommon among local survivors. Both drinking and smoking rates were lower in this study than in studies from other developed countries.9 19 34 However, the reported rate (20.5%) of exposure to second-hand smoke in the home was surprisingly high. We speculate that this high rate is because the smoking rates of individuals above the age of 40 years remain relatively high in the general population (16.9% to 26.2% in men and 1.3% to 5.1% in women).35 Older family members, particularly men, might remain the main source of second-hand smoke for survivors. This observation underscores the need for continual efforts to encourage survivors to abstain from harmful health practices (particularly during the early survivorship phase) and the need for smoking cessation interventions to be provided for the comparatively few survivors and family members who are current smokers.

In this study, lower socioeconomic status was significantly associated with poor health practices. The association between possession of private medical insurance and immunisation practice was close to statistically significant, further suggesting that socioeconomic disparities hinder access to preventive care among cancer survivors. Underserved survivors may require special navigation services to support their adherence to surveillance, preventive care, and health-protective behaviours.36 Considering that only half of the survivors had private health insurance, collaborations between clinicians and policymakers could enable the establishment of a universal vaccination and late-effects screening programme for cancer survivors. Local research is needed to identify barriers to—and facilitators of—quality care and effective methods of outreach to underserved survivors.

Most survivors indicated that they would prefer to be enrolled into a survivorship programme early in the cancer care continuum. This is a promising prospect because survivors who had early access to structured survivorship programmes reportedly were more aware of their late effects, visited emergency departments less frequently, had higher cancer-specific health literacy, and tended to experience less emotional stress.3 Therefore, a structured survivorship programme is recommended to include cancer and late-effects screening, a specialist referral network, and psychosocial services for survivors and caregivers (Fig 3).4 12 In Hong Kong, the five major institutions that provide paediatric oncology care typically include these core services in their long-term follow-up programmes, although the specific services offered may differ among institutions. Overall, the centralisation of paediatric oncology services in the new Hong Kong Children’s Hospital has provided an unprecedented opportunity for oncologists and allied health professionals to initiate a formal paediatric cancer survivorship programme in Hong Kong. This will facilitate the development of a survivorship care model that is tailored to the healthcare system in Hong Kong.

Our participants regarded services concerning health issues (eg, education and screening for late effects) as the most important aspects of survivorship care. The COG has developed a set of “risk-based” guidelines, which refer to a personalised systematic plan of regular screening, surveillance, and prevention strategies based on a patient’s treatment, cancer experience, and personal factors.5 10 In an effort to improve the awareness of health issues in Chinese cancer survivors, we collaborated with the COG and launched a Chinese version of the Health Links patient education materials in May 2020.10 To our knowledge, this is the first set of publicly available authoritative resources regarding late effects that is written in a native Chinese language. Such initiatives are anticipated to assist survivors in taking age-appropriate ownership of their health and engaging as active partners with their health providers during the survivorship phase.

Our findings should be considered in the context of the following limitations. First, this single-centre study comprised a moderately small sample of survivors who were recruited through a convenience sampling approach. Moreover, eligible participants were identified from a long-term follow-up clinic that had a mean loss to follow-up rate of 15% to 20%. This is a recognised challenge in survivorship research because this population is often lost to follow-up from primary paediatric clinics as a result of their growing independence and mobility during advancement into adulthood.37 These study limitations may have introduced sampling bias because our participants may have been more likely to be health conscious than non-participants and survivors who had been lost to follow-up. Hence, the true uptake of health-protective behaviours among local survivors may be lower than the rates reported in this study, and our findings might not be generalisable to other survivors of childhood cancer in Hong Kong. Second, social desirability and recall bias may have affected the accuracy of the self-reported results. Future studies should adopt validated and more sensitive instruments to achieve a more objective evaluation of health behaviour. For example, physical activity and sleep can be better measured with actigraphy studies. Finally, the multiple predictors and covariates analysed in this study may have increased the risk of a Type I error. However, lifestyle itself is a complex phenotype that is likely to be influenced by intrinsic and extrinsic factors. Our findings should be validated using a larger-scale study that involves the prospective collection of outcome data to better reflect the trajectory of health behaviour changes and correlate these findings with the results in local cancer survivors.

Despite the low prevalences of health-damaging behaviours, the frequencies with which Hong Kong survivors of childhood cancer engaged in health-protective behaviours were unsatisfactory. These findings highlight the need to empower survivors to adopt health-protective behaviours. A potential intervention opportunity may involve engaging survivors and families in a structured comprehensive survivorship programme during their transition to survivorship. A multidisciplinary and interactive programme addressing late effects and psychosocial aspects may address the multifaceted needs of Hong Kong survivors of childhood cancer. Future work should aim to improve preventive care for underserved groups through advocacy and care coordination.

Concept or design: All authors.
Acquisition of data: YT Cheung, LS Yang, JCT Ma, PHK Woo, TCH Chan, SMS Luk.
Analysis or interpretation of data: YT Cheung, LS Yang, JCT Ma, PHK Woo, TCH Chan, SMS Luk.
Drafting of the manuscript: YT Cheung, TCH Chan, SMS Luk.
Critical revision of the manuscript for important intellectual content: All authors.

All authors had full access to the data, contributed to the study, approved the final version for publication, and take responsibility for its accuracy and integrity.

All authors have disclosed no conflicts of interest.

We thank Dr Smita Bhatia and Dr Wendy Landier from the Institute for Cancer Outcomes and Survivorship, The University of Alabama in Birmingham, for serving as consultants on this project.

A portion of this work was presented at the 52nd Congress of the International Society of Paediatric Oncology (SIOP)–Virtual conference (14-17 October 2020), as well as the HKPS/HKCOP/HKPNA/HKCPN Joint Annual Scientific Meeting on 7 November 2020.

This study was supported by the Health and Medical Research Fund Research Fellowship, the Food and Health Bureau, The Government of the Hong Kong Special Administrative Region (Ref 03170047).

The study protocol was approved by The Joint Chinese University of Hong Kong–New Territories East Cluster Clinical Research Ethics Committee (Ref: 2018.338). Written informed consent was obtained from all participants.

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