The contemporary world has seen the exponential rise of cancer prevalence in the aging population to somewhat alarming levels. This segment consists of individuals aged 65 years and above and is the fastest growing age group in the United States not only as absolute numbers of persons in the general population but also as a proportion of the total population. (Ershler & Longo, 1997). Recent statistics indicate that one in every eight people in America aged 65 years, and above develops cancer, with women accounting for 58% of all cancer cases (Browner, 2015). Since cancer risk increases with advancing age, the old account for 56% and 70% of all new cancer diagnoses and mortalities in the country (Yancik, 2005 as cited in Browner, 2015). The Cancer burden in the aged is likely to be compounded in the coming years by the ballooning population of the elderly. In 2000, the aging population made up 13% of the American population, totaling to approximately 35 million people. However, this figure will double by 2050, amounting to nearly 70 million people (Berger et al., 2006). Thus, health practitioners are likely to experience complexities in care delivery to older cancer patients since the aged are susceptible to other systemic medical conditions. This paper, therefore, explicates the biological causes of high cancer incidences among the elderly and evaluates the treatment efficacy of cancer interventions.
The majority of the new cancer diagnoses among the elderly include breast and prostate. Other common forms of cancer among the aging population include higher incidences of lung, throat and colon cancers and non-Hodgkins lymphoma (Browner, 2015). These diseases are increasingly becoming common among this segment of the population predominantly because several common diseases tend to occur in combination at this stage making advancing age an important risk factor for cancer development (Berger et al. 2006). Statistics presented by Browner (2015) indicate that breast cancer alone accounts for more than 200,000 new cases each year, with older women possessing a lifetime risk of 12%. For elderly men, the lifetime risk of developing prostate cancer is 13% with a mortality rate of 3% (Browner, 2015). The low death rate may stem from the extensive awareness campaigns in the country that have made early detection and treatment possible. Lung cancer accounts for nearly 70% of all new cancer incidences in the aging population and causes close to 30% of all cancer deaths in the country (Browner, 2015). The positive correlation between cancer incidence and age portends an exponential growth of cancer burden in the country due to the swelling population. According to Berger et al. (2006), this expected population surge results from higher life expectancy, a greater number of ‘baby boomers’ hitting 65 years and lower birth rates among the younger generation. ‘Baby Boomers is that segment of the US population made of individuals born between 1946 and 1964 in the post-WWII era ( Berger et al., 2006).
Older people are becoming centenarians – living to greater ages due to several factors spanning across socio-economic, lifestyle and health care factors. In this United States, for example, people are living longer due to the availability of efficient and affordable medical health care, better retirement packages provided by the necessary social security fund, and mandatory health insurance policies that guarantee better healthcare for the elderly. Moreover, nursing homes for the elderly have similarly played significant roles in lengthening the lifespan of most of the US’s aging population. Additionally, the younger generation spends most of their youth building their careers and chasing the ever-elusive American dream, leading to lower birth rates. If this trend persists, the aging population will expand significantly in the next decades, hence increasing their cancer burden on the overall economy. Another key contributor to the high cancer incidences among the aged is the prevalence of “cancer-causing behaviors” among the general population (Jemal, Bray, Ferlay, Ward & Forman, 2011). While some of the older individuals take up smoking and alcoholism at their advanced age, the majority of the older cancer patients adopted such harmful lifestyles during their younger years. The accumulated detrimental effect of such behaviors on their health increases their risk of developing certain forms of cancer.
Aging is one of the highest risk factors for cancer just like in most other diseases such as heart diseases that are increasingly becoming prevalent with advancement in age. Balducci and Extermann (2000) define aging as a gradual loss of one’s stress tolerance owing to a decline in the functional capacities of several organ systems, reduced cognition, and high occurrence of comorbidities. Higher incidences of diseases among the old is mainly attributed to the suppression of body defense system with the increase in age leaving the body more readily susceptible to illness. Health deterioration caused by these conditions increase the severity of cancer in older patients (Balducci & Extermann, 2000). From a biological perspective, aging causes molecular, cellular, and physiologic changes in the human body that create fertile grounds for carcinogenesis (Ershler & Longo, 1997). Molecular changes arise from a dysfunction in the DNA repair system such as a DNA covalently bonding to a carcinogenic chemical, higher rates of gene mutations and chromosomal breakage, and genetic instability caused by the activation of oncogenes (mutated genes) (Browner, 2015). Cellular changes result when some cells in the human body undergo senescence as a consequence of aging. Senescence – the progressive deterioration of cells – causes stem cells to accumulate stress-dependent changes and damage over the years (Finkel, Serrano & Blasco, 2007). Senescence may be either proliferative or replicative in nature (Browner, 2015). When cells experience proliferative senescence, they retain their biological activity but without undergoing any cell division.
On the other hand, replicative senescence occurs when cell growth becomes irreversibly stunted after achieving a fixed number of cell divisions. The cessation of cell division stems from the gradual shortening of the “distal chromosome tip (telomere)” until the division of the cell becomes unfeasible (Ershler & Longo, 1997). Since older people experience stunted apoptosis (slower degeneration of dead cells), the increased accumulation of senescent cells in the differentiated tissues causes incipient tumors to develop (Finkel et al., 2007). These pre-malignant phenotypes create conducive microenvironments for tumorigenesis and carcinogenesis. Physiologic changes in the elderly include a less optimum performance of various organs and tissues in the body. Diminished “glomerular filtration rate”, mass, and blood flow to the kidneys and liver increase the risk of organ failure, thus contributing to slower cellular repair mechanisms and a decline in stem cell reserves in the bone marrow (Olver, 2000). The consequence is the inefficient metabolism and excretion of drugs and slower recovery that increases the risk of developing treatment-related toxicities.
While multiple cancer treatment options are available in healthcare facilities, older patients face certain hurdles in accessing such medical care due to several reasons. Such hindering factors include paternalistic concerns about their age and a perceived low tolerance level of their body immune system to aggressive treatments such as chemotherapy. The common barrier to effective cancer diagnosis and treatment among the elderly is the assumption that older patients are frail and cannot withstand some forms of therapy such as surgery. This assumption may be true for individuals aged 70 years and above or those suffering from critical medical conditions such as anemia that make surgery inapplicable. However, for individuals just hitting the 65-year mark, their bodies may be strong enough to withstand such treatments (Ershler & Longo, 1997). Thus, the problem is not age per se but the erroneous assumptions made by health practitioners without appropriate medical testing, which denies older cancer patients the right to make informed decisions regarding the available treatment options. Other barriers to healthcare include the absence of standard guidelines regarding more elderly cancer patients, overestimation of the impact of comorbidities, and limited access to cancer screening and care (Browner, 2015).
The lack of health guidelines for older patients arises from the limited participation of the aged in cancer clinical trials, thus yielding little information on the peculiarities of cancer prognosis in this age group. In a study to investigate the underrepresentation of the aged in such tests, Lewis et al. (2003) found that the aging population comprises only 25% of the participants in clinical trials for cancer. The study also shows that the disparity between representation and the huge cancer burden of the aged is even more distinct in clinical trials for early-stage cancers than for those involving late stage cancers. The primary reason for underrepresentation is the protocol exclusion of most elderly participants based on their cumbersome medical histories involving diminished functional status and organ abnormalities (Lewis et al., 2003). Moreover, the elderly lack access to care due to transportation difficulties, the absence of social support structures, expensive medical care, and the inability to coordinate with their primary physicians.
In order to reduce the burden of cancer among the aging population, certain measures must be adopted both at the individual and societal level. First, individuals, both young and old individuals, must be willing and able to make lifestyle changes aimed at minimizing cancer-causing behaviors such as smoking and alcoholism. Studies show that smoking is one of the causative agents of cancer among cigarette smokers (Jemal et al., 2011).The onset of smoking at very young ages increases the risk of developing lung cancer in the latter years due to the prolonged exposure of such delicate organs to tobacco by-products (Jemal et al., 2011). On the other hand, excessive alcoholism has been linked to higher vulnerability to cancers of the liver and pancreas (Jemal et al., 2011).Secondly, intensive and widespread sensitization programs should be instituted and rolled out at both the local and nation levels targeting all segments of the population. In schools, for instance, awareness campaigns regarding cancer-risk behaviors should be intensified among the younger generation in efforts to curtail the rise in cancer burden among the elderly later in their years (Center for Disease Control and Prevention [CDC], 2014). Thirdly, dietary considerations that emphasize the consumption of vegetables and fruits should be adopted by older individuals to strengthen their immune systems (Shibata, Paganini-Hill, Ross, & Henderson, 1992). According to Shibata, Paganini-Hill, Ross & Henderson (1992), the combined intake of fruits and vegetables, dietary vitamin C, and beta-carotene reduces the risk of cancer in women.
Furthermore, the additional use of vitamin A and C indicated an increased protection against colon cancer in women. While the results of the study were statistically insignificant, they offer insight into dietary changes that can give the elderly a fighting chance against cancer. Third, guidelines for cancer clinical trials should be amended to make the representation of the aged commensurate with their cancer burden. Their inclusion in such trials will yield insights into the peculiarities of diagnosis and treatment of older cancer patients. Such information will assist policymakers in standardizing care based on realistic scientific assumptions. Trials also offer novel treatment options that are not yet in the public domain, thus increasing the chances of survival (American Society of Clinical Oncology [ASCO], 2012). Moreover, the older participants also benefit from expert care in leading healthcare institutions, and may obtain “trial sponsors” to cover the cost of participation in the trials such as accommodation, meals, and transportation (ASCO, 2012).
Lastly, healthcare professions should conduct a comprehensive assessment of older patients to be able to recommend cancer treatment options that match their health status. Such considerations should include functional status, comorbidities, nutritional status, socioeconomic status, polypharmacy, and geriatric syndromes (Browner, 2015; Lichtman, 2003). Functional status includes the evaluation of the capacity of older cancer patients to engage in “activities of daily living (ADL)” – those activities necessary for independent living such as bathing, eating, dressing and toileting (Lichtman, 2003). Individuals incapable of meeting these criteria warrant hospitalization if they lack the necessary support from their friends and families. Comorbidities refer to medical conditions that occur in combination, thus complicating care interventions in cancer patients. Practitioners should assess the number, type, and acuteness of such conditions for the purposes of recommending accurate dosages and drug combinations. Yancik (1997) maintains that there exists a positive correlation between comorbidity and age. Accordingly, individuals aged between 55 and 64 years suffer from at least two conditions, while those aged 65 years and above exhibit, at least, three or four conditions.
The top five conditions experienced by older cancer patients include hypertension, heart-related conditions, arthritis, gastrointestinal problems, and anemia (Yancik, 1997). Nutritional status determines whether the body can withstand the side effects of certain medications and therapies such as surgery, radiation, and chemotherapy. This assessment aids practitioners in drug prescription and setting treatment intervals for the elderly. Socioeconomic status evaluates whether a patient can meet the medical and transportation costs incurred during treatment. Those unable to meet transportation expenses may require hospitalization during the treatment period. Geriatric syndromes such as delirium, dementia, depression, osteoporosis, and falls should be treated as red flags for possible cancer incidences since they are responsible for delayed cancer screening and diagnoses (Berger et al., 2006; Browner, 2015). Lastly, polypharmacy evaluates body-drug and drug-drug interactions. Body-drug interactions comprise of an approximation of the rate at which the bodies of elder patients absorb, metabolize, and excrete drugs (Balducci, 2014). This assessment is important because aging hampers normal physiological processes that may increase drug toxicities in the body.
In conclusion, aging increases cancer risk by causing cellular, molecular, and physiologic changes in the body that make the elderly susceptible to the disease. Loss of body immunity against most diseases, in turn, leads to the body falling to multiple and in most cases combinational disease attacks. The cancer burden affecting the aging population is likely to increase exponentially in the coming decades. As pointed out previously crucial contributory factors to this situation are factors such as a general rise in the population life expectancies, population explosion due to increased birth rates and reduced rates of infant and general population mortality, and higher adoption of cancer-risk behaviors. The latter factor has increasing become an important factor in influencing the number of new cancer among the elderly population. Despite the availability of several cancer treatment options in the market, their accessibility remains limited to the old due to paternalistic assumptions and erroneous generalizations of care needs by practitioners. Coupled with poor socioeconomic status, absent social support systems, and underrepresentation in cancer clinical trials, the aging population remains more vulnerable to cancer development. The possible solutions such difficulties include good nutrition, lifestyle changes, inclusion in clinical trials, and a comprehensive assessment of the healthcare needs of older patients. Overall, the onus of responsibility lies with both the individual and the society to hasten early screening, diagnosis, and treatment of cancer before they metastasize to irreversible levels.
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