Cancer Survivorship Challenges

Advances in cancer screening and early detection, improvements in therapeutics, and supportive care all contribute to decreasing cancer mortality. Figure 1 shows the changing demographic characteristics of the cancer population from 1975 through 2040. There will be an estimated 26 million survivors in 2040, the majority of whom will be in their 60s, 70s, or 80s.¹ Nearly every health care provider will encounter cancer survivors. This review is primarily intended for primary care physicians, obstetrician–gynecologists, midlevel providers, and subspecialists who have patients who are cancer survivors. The review also serves as a primer for surgeons, radiotherapists, and medical oncologists who may not be familiar with the broad topic of survivorship. At present, the care of cancer survivors is often an afterthought, tends to be fragmentary, and is not well integrated into the mainstream of cancer care. Also, the best models for providing survivor care remain undefined.

According to the Office of Cancer Survivorship at the National Cancer Institute² and other organizations (e.g., the Centers for Disease Control and Prevention and the National Coalition for Cancer Survivorship), survivorship starts at the time of diagnosis and lasts throughout the lifespan. This holistic definition encourages clinicians to think about the care of survivors as an integral part of the cancer care continuum. Included in the definition of survivors are family members, friends, and caregivers. The primary reason for including these persons is that in most cases cancer is not experienced alone. Caregivers are the unsung heroes, providing physical and emotional support to the cancer survivor. Recognition of the adverse health effects and emotional toll on caregivers is part of this broad definition of survivorship.

The National Academies of Sciences, Engineering, and Medicine, in a landmark publication, identified the essentials of survivor care,³ and these were expanded in the American Society of Clinical Oncology (ASCO) Core Curriculum for Cancer Survivorship Education.⁴ The topics addressed in these reports are reviewed below.

Surveillance for Recurrence and Screening for Second Primary Cancers

Table 1.Suggested Site-Specific Surveillance Recommendations for Cancer Survivors.

ASCO,^5-7 the National Comprehensive Cancer Center Network (NCCN),⁸ the American Cancer Society,^9,10 the Children’s Oncology Group,¹¹ and other organizations^12-16 issue site-specific guidelines for the follow-up care of cancer survivors (Table 1). With few exceptions, these are not evidence-based guidelines but are instead based on expert consensus. The evidence that surveillance for metastases reduces cancer mortality or improves health-related quality of life is limited. The basis of most surveillance recommendations is knowledge of the cancer-specific natural history of recurrence or an analysis showing that the benefits of surveillance testing outweigh its harms. However, the benefits-outweigh-harms analysis does not take into account the distress that surveillance testing causes and the financial costs of such testing.

Randomized, controlled trials of surveillance testing have had opposite results in two different populations of cancer survivors. Randomized trials do not support surveillance for metastatic disease in asymptomatic female survivors of breast cancer⁶ (Table 1). In a minority of cases, imaging or measurement of serum tumor markers reveals metastases before they become symptomatic. However, the overall survival is unchanged between the asymptomatic screened population and women who undergo surveillance testing when they are symptomatic. In contrast, survivors of colorectal cancer undergo periodic surveillance imaging and tumor-marker testing (Table 1). Metastatic disease in the liver occurs in 60% or more of colorectal cancer survivors, and in 20 to 35% of patients with metastatic disease, the metastases are resectable.¹⁷ Surveillance improves the likelihood of finding resectable hepatic metastases. Randomized trials show that liver resection with systemic chemotherapy results in long-term survival in some cases.¹⁸

All persons with potentially curable cancers should have the recommended sex- and age-specific routine screenings, tests, and care that are recommended for the general population (e.g., colonoscopy, mammography, Papanicolaou smears and human papillomavirus testing, dual-energy x-ray absorptiometry [DXA], vaccinations, and screening for hypertension, lipid abnormalities, and diabetes). Screening recommendations for new primary cancers in cancer survivors may differ from the screening recommendations for healthy persons with no history of cancer. For example, Hodgkin’s disease survivors who have been treated with mantle irradiation have an increased risk of breast cancer.¹⁹ Among women who underwent mantle irradiation for the treatment of Hodgkin’s disease in adolescence, annual breast screening with magnetic resonance imaging (MRI) beginning at 25 years of age is associated with a reduction in mortality from breast cancer, as compared with breast screening starting at 40 years of age.²⁰

Long-Term and Late Effects of Cancer Treatment

Table 2.Long-Term and Late Effects of Treatment for Cancer.

Long-term treatment effects are side effects that begin during and extend beyond treatment,^21-34whereas late effects occur after treatment ends^32,35-38 (Table 2). Both late and long-term effects vary according to treatment exposures and individual host factors. Also, radiation causes late effects with long latency periods — primarily, radiation-induced second cancers and cardiovascular disease.^35,39,40

An emerging concept is that chemotherapy causes premature or accelerated aging in both survivors of cancer in adulthood and survivors of cancer in childhood.^41,42 In addition to increased coexisting conditions in cancer survivors, healthy aging and chemotherapy-related side effects have several putative biomarkers in common, including telomere shortening, decreases in maximal oxygen consumption, and increased levels of inflammatory cytokines. Hormone deficiencies also contribute to senescence.⁴³ Chemotherapy causes primary hypogonadism in premenopausal women, and long-term treatment with antiandrogens, gonadotropin hormone–releasing agonists, and antiestrogens suppresses circulating androgen and estrogen levels.

Premature aging is most evident in survivors of childhood cancers, the majority of whom have coexisting medical conditions, which may be life-threatening, by the age of 45 years.⁴⁴ Trying to distinguish chemotherapy-related accelerated aging from the natural aging process in adults can be challenging. For example, the rates of cardiac events in the general population increase with aging, and such events also occur as a rare late effect of treatment with anthracyclines (e.g., cardiomyopathy) and radiation therapy (e.g., microvessel disease, myocardial infarction, and cardiomyopathy).⁴⁵ Another example is sarcopenia. A muscle-wasting syndrome similar to cancer cachexia, sarcopenia occurs as part of normal aging⁴⁶ and also occurs in some cancer survivors treated with chemotherapy.⁴⁷

Treatment of late and long-term effects in cancer survivors is often extrapolated from the treatment of the same medical conditions in populations without cancer. Osteoporosis serves as an example. Generally, trials of treatment in cancer survivors rely on a surrogate end point for fracture: the measurement of bone mineral density from DXA. Decreasing bone mineral density results in reduced T scores, which predict fractures. Several guidelines outline approaches to preventing and treating osteoporosis in cancer survivors. (For references, see the Supplementary Appendix, available with the full text of this article at NEJM.org.)

Health Promotion

Weight management,⁴⁸ increased physical activity,⁴⁹ a healthful diet,⁵⁰ smoking cessation,⁵¹and reduced alcohol consumption⁵² are the foundation for improved health and wellness for everyone, and especially for cancer survivors. Obesity is a risk factor for the development of several common cancers (e.g., breast, colon, and prostate cancers). It increases mortality among breast-cancer survivors and may increase mortality among survivors of prostate or colon cancer. Randomized trials are testing whether obese survivors of breast cancer who lose weight and increase their physical activity have improved disease-free survival and declines in cancer mortality.⁵³

Physical activity improves health-related quality of life and symptom management in cancer survivors, and it may decrease cancer mortality among survivors of some cancers.⁴⁹ Tobacco cessation and referral to smoking-cessation programs are essential components of care for survivors. However, cancer survivors are no more likely to quit smoking than the general population, and about half of them do not receive smoking-cessation counseling.⁵¹ Alcohol is a dose-dependent risk factor for the development of multiple cancers, and continued consumption of alcohol appears to increase cause-specific mortality among survivors with various cancers.⁵²

Promotion of Psychological Well-Being

Table 3.Risk Factors and Interventions for Psychosocial Issues.

Depression and anxiety,⁵⁴ post-traumatic stress disorder (PTSD),⁵⁵ fear of recurrence,⁵⁶ and return-to-work and financial issues⁵⁷ are among the psychological consequences of living beyond cancer. Typically, these conditions are underdiagnosed and undertreated, despite the availability of effective psychosocial and drug interventions (Table 3).

Although cancer survivors, over time, tend to return to former levels of activity and productivity, many experience distress. Distress occurs on a spectrum extending from adjustment disorders that are just below the threshold of mental disorders to diagnosable psychiatric illnesses (e.g., a major depressive episode).⁵⁸ Distress screening is one of the mandates of the American College of Surgeons Commission on Cancer for hospital accreditation. There are many instruments for distress screening. The NCCN distress thermometer is a one-item numerical rating scale that has been labeled the “sixth vital sign.”⁵⁹As with screening for depression and anxiety, distress screening before a clinic visit is intended to trigger a response from the health care team if a patient’s score exceeds a threshold value. Depending on local expertise, the patient should be referred to a social worker, nurse practitioner, psychologist, or another health care professional for assessment and triage.

Special Populations

OLDER SURVIVORS

The percentage of cancer survivors over the age of 65 years continues to grow (Figure 1). This burgeoning population of older cancer survivors poses one of the most important challenges facing the health care system. Efforts are under way to meet this challenge and identify gaps in knowledge (see the Supplementary Appendix for references). In part, these efforts entail the measurement of end points such as active life expectancy, or the time spent living independently with functional status and cognition intact. Older cancer survivors may not have the same goals as younger adult survivors.⁶⁰ For younger patients, prolonged survival may be the primary goal, whereas older patients may value independent functioning and preservation of cognition over length of life.⁶⁰

A geriatric assessment can facilitate the care of older cancer survivors. This tool predicts functional status, frailty, coexisting conditions, and risk of death, and the assessment may change decisions regarding the aggressiveness of cancer treatment.⁶¹ Despite all the benefits of the geriatric assessment, its incorporation into routine oncology practice has been slow. The practice demands of busy oncologists make a full geriatric assessment burdensome.

There are many screening tools to identify patients who require a geriatric assessment.⁶¹According to the International Society of Geriatric Oncology, the Geriatric 8 is the preferred screening tool, but others are validated and recommended (e.g., Vulnerable Elders Survey–13 and the Triage Risk Screening Tool).⁶¹ The Geriatric 8 is an eight-item scale that covers chronologic age, body-mass index, food intake, weight loss, mobility, neuropsychological problems, use of prescription drugs, and self-rating of health status. The survey takes about 4 to 5 minutes to complete and has the highest sensitivity for predicting an abnormal geriatric assessment.⁶¹ The increase in the number of older cancer survivors that is expected over the next 20 years (Figure 1) necessitates the incorporation of the Geriatric 8 or other screening tools into routine oncology practice to assess frailty, predict the severity of treatment-related side effects, and predict the risk of death.

SURVIVORS OF CHILDHOOD CANCERS

An estimated 80% or more of cancers in children are cured.⁶² However, the most pressing problems for childhood-cancer survivors are treatment-related second cancers and coexisting medical conditions.⁶³ The Children’s Oncology Group Long-Term Survivor Study is a wellspring of information about childhood-cancer survivorship,¹¹ with guidelines for long-term follow-up based on treatment exposure and risk.

Adult survivors of childhood cancers have significant declines in functional status, increased limitations on activity, poorer mental health status, and poorer general health than a matched sibling control cohort.⁴⁴ Many adolescent and young adult survivors of childhood cancer are unaware of their increased health risks,⁶⁴ and the National Academies of Sciences, Engineering, and Medicine has identified this group as an especially vulnerable survivor population.³ Common problems of adolescent and young adult survivors are infertility, other reproductive health problems, and psychosocial issues.⁶⁵

CAREGIVERS

The burdens of caregiving are so great that Golant and Haskins have named caregivers the “other cancer survivors.”⁶⁶ In fact, the problems that caregivers and cancer survivors have are strikingly similar. Fatigue, insomnia, loss of physical strength, loss of appetite and weight, depression, anxiety, PTSD, and lost income are some of the problems associated with caregiving.⁶⁷

A 2015 report by the National Alliance for Caregiving highlights caregivers’ burdens.⁶⁸ This report summarizes the results of an online survey of 1248 caregivers, with caregivers defined as those who provide unpaid care for family members or friends 18 years of age or older to help them take care of themselves. This survey was not specific to cancer survivors, but the results are considered to be generalizable.

Key findings from the report include an overall caregiver prevalence of 44 million people, the majority of whom provide care for persons over 50 years of age. Two thirds of the survey respondents were women, and one half said they “had no choice” in becoming a caregiver. Two thirds of the caregivers also reported some interference with their paid work. One third of the respondents reported discussing the needs of the care recipient with the health care team. However, only one sixth of the caregivers had a conversation about their own needs and resources to address those needs. These survey results are a stark reminder that the caregivers are woefully underserved and yet essential as more cancer care is home-based. Making caregivers aware of available resources is important; in addition, psychosocial interventions, including cognitive behavioral therapy, may be helpful.⁶⁹

Another survey, the National Quality of Life Survey for Caregivers, identified more than 1000 caregivers who provided ongoing care for survivors of breast, lung, colorectal, and prostate cancers.⁷⁰ The survey population comprised three groups: current caregivers, caregivers whose cancer survivors were in remission, and bereaved caregivers. In multivariate analyses, becoming a bereaved caregiver caused significant declines in mental health scores, as compared with the scores for current caregivers. These findings show that the process of caregiving is not static but is dynamic over time. Caregivers’ needs change with the changing needs of the recipient of care.

Care Coordination and Communication

Table 4.Models of Care Delivery for Cancer Survivors.

An ASCO position statement, “Achieving High-Quality Cancer Survivorship Care,”⁷¹ identified four critical aspects of survivor care: developing the best models of care for cancer survivors, articulating the purpose of a treatment summary and individualized care plan (referred to as a survivor care plan), identifying gaps in research, and ensuring access to care for survivors. Cancer survivors receive less routine care (noncancer-related) than healthy controls if the follow-up care is provided by an oncologist, they receive more routine care if they see a primary care provider for follow-up care, and they receive the highest level of care if they see both an oncologist and a primary care provider or participate in a shared-care model⁷²(Table 4).

An emerging concept tied to the shared-care model is risk stratification of survivors.^73,77Survivors are assigned to low-risk, intermediate-risk, and high-risk categories on the basis of the cancer treatment they received and the risk of recurrence. For example, a patient with early-stage lung or colorectal cancer whose primary treatment was surgery alone would be designated as a low-risk survivor, whereas a patient who underwent allogeneic bone marrow transplantation and has risks of multiorgan side effects would be designated as a high-risk survivor.

A systematic review of primary care physicians worldwide revealed that they wished to share care with oncologists but identified several barriers.⁷⁵ These include lack of expertise, skills, and knowledge to provide care for cancer survivors and lack of standards for delivering such care. These barriers reflect a lack of communication and care coordination between oncologists and primary care providers. An increased workload with limited time, the increased financial burden of providing care for cancer survivors, inadequate access to mental health services, and medicolegal risks were also cited as barriers.

Another study, which focused on primary care providers located in urban, suburban, and rural regions of the United States, identified two critical barriers to the incorporation of survivor care in routine clinical practice.⁷⁶ First, primary care providers did not view cancer survivors as a distinct patient population and had difficulty identifying them in the electronic medical record. Second, primary care providers received limited information regarding the follow-up of cancer survivors. What information they did receive was not useful or was outdated.

To enhance communication among oncologists, primary care providers, and cancer survivors, the National Academies of Sciences, Engineering, and Medicine recommended generating a survivor care plan. Part of the impetus for the care plan was that many cancer survivors do not know what treatments they received and relocate several times during their lifetimes. Survivor care plans enhance communication between oncologists and primary care physicians, and in an interview study, primary care physicians valued the information in the survivor care plan and felt more confident in providing care for cancer survivors.⁷⁸ The value of such care plans to cancer survivors is less clear, since randomized, controlled studies with short-term follow-up have thus far failed to show improvement in health-related quality of life or reduction in distress for cancer survivors who received care as part of an individualized survivor care plan versus those who received usual care.⁷⁹ Ongoing studies are assessing the value of survivor care plans for primary care providers and cancer survivors.⁸⁰

Table 4 describes the models of care for survivors.^73,74 However, there is a lack of information about which models improve health-related quality of life, reduce distress and coexisting conditions, and increase survival. Also, little is understood about the cost-effectiveness of the models.⁸¹ Nekhlyudov et al. have described various models of care shared by oncologists and primary care providers.⁷³ These include a model in which primary care providers are integrated into the staff of providers at site-specific cancer clinics and an oncogeneralist model, in which a primary care provider with experience in survivor care sees cancer survivors in consultation.

It is axiomatic that part of survivor care is preventing a recurrence of cancer. Oncologists and primary care providers have a responsibility to communicate effectively.⁸² For example, nonadherence and discontinuation of antiestrogen treatments may lead to increases in breast-cancer mortality.⁸³ Good patient–physician communication and the establishment of realistic expectations about the benefits and side effects of antiestrogen agents in breast-cancer survivors improve treatment adherence.⁸⁴ Likewise, good communication fosters adherence to antiandrogen treatment in prostate-cancer survivors.⁸⁵

Conclusions

The increasing population of cancer survivors presents several challenges and opportunities. Cancer survivors and caregivers have some of the same needs, and their needs change over time. The two most pressing challenges are meeting the needs of the growing population of older cancer survivors and providing care for survivors of childhood cancer who have treatment-related cancers and coexisting medical conditions. Some models exist for providing survivor care, but there are scant data on their effectiveness in improving survivorship outcomes.

As advances in prevention and treatment lead to reduced cancer mortality, expanded research, funding, and resources will be required for survivor care. Additional research in health disparities among cancer survivors is needed. Finally, increasing efforts in wellness promotion are needed for cancer survivors, their caregivers, and the general population. If we successfully meet these challenges, the community of cancer survivors and caregivers will enjoy a better health-related quality of life and a smoother transition into the mainstream of life.

https://www.nejm.org/doi/full/10.1056/NEJMra1712502