Cancer in the elderly

Defining Undertreatment and Overtreatment in Older Adults With Cancer: A Scoping Literature Review

PURPOSE

The terms undertreatment and overtreatment are often used to describe inappropriate management of older adults with cancer. We conducted a comprehensive scoping review of the literature to clarify the meanings behind the use of the terms.

METHODS

We searched PubMed (National Center for Biotechnology Information), Embase (Elsevier), and CINAHL (EBSCO) for titles and abstracts that included the terms undertreatment or overtreatment with regard to older adults with cancer. We included all types of articles, cancer types, and treatments. Definitions of undertreatment and overtreatment were extracted, and categories underlying these definitions were derived through qualitative analysis. Within a random subset of articles, C.D. and K.P.L. independently performed this analysis to determine final categories and then independently assigned these categories to assess inter-rater reliability.

RESULTS

Articles using the terms undertreatment (n = 236), overtreatment (n = 71), or both (n = 51) met criteria for inclusion in our review (n = 256). Only 14 articles (5.5%) explicitly provided formal definitions; for the remaining, we inferred the implicit definitions from the terms' surrounding context. There was substantial agreement (κ = 0.81) between C.D. and K.P.L. in independently assigning categories of definitions within a random subset of 50 articles. Undertreatment most commonly implied less than recommended therapy (148; 62.7%) or less than recommended therapy associated with worse outcomes (88; 37.3%). Overtreatment most commonly implied intensive treatment of an older adult in whom the harms of treatment outweigh the benefits (38; 53.5%) or intensive treatment of a cancer not expected to affect an older adult in his/her remaining lifetime (33; 46.5%).

CONCLUSION

Undertreatment and overtreatment of older adults with cancer are imprecisely defined concepts. We propose new, more rigorous definitions that account for both oncologic factors and geriatric domains.

High-dose [131I]tositumomab (anti-CD20) radioimmunotherapy and autologous hematopoietic stem-cell transplantation for adults > or = 60 years old with relapsed or refractory B-cell lymphoma

PURPOSE

The majority of patients with relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL) are older than 60 years, yet they are often denied potentially curative high-dose therapy and autologous stem-cell transplantations (ASCT) because of the risk of excessive treatment-related morbidity and mortality. Myeloablative anti-CD20 radioimmunotherapy (RIT) can deliver curative radiation doses to tumor sites while limiting exposure to normal organs and may be particularly suited for older adults requiring high-dose therapy.

PATIENTS AND METHODS

Patients older than 60 years with relapsed B-cell NHL (B-NHL) received infusions of tositumomab anti-CD20 antibody labeled with 185 to 370 Mbq (5 to 10 mCi) [131I]-tracer for dosimetry purposes followed 10 days later by individualized therapeutic infusions of [131I]tositumomab (median, 19.4 Gbq [525 mCi]; range, 12.1 to 42.7 Gbq [328 to 1,154 mCi]) to deliver 25 to 27 Gy to the critical normal organ receiving the highest radiation dose. ASCT was performed approximately 2 weeks after therapy.

RESULTS

Twenty-four patients with a median age of 64 years (range, 60 to 76 years), who had received a median of four prior regimens (range, two to 14 regimens), were treated. Thirteen patients (54%) had chemotherapy-resistant disease. The estimated 3-year overall and progression-free survival rates were 59% and 51%, respectively, with a median follow-up of 2.9 years (range, 1 to 6 years). All patients experienced expected myeloablation with engraftment of platelets (> or = 20 K/microL) and neutrophils ( 500/microL), occurring at a median of 9 and 15 days after ASCT, respectively. There were no treatment-related deaths, and only two patients experienced grade 4 nonhematologic toxicity.

CONCLUSION

Myeloablative RIT and ASCT is a safe and effective therapeutic option for older adults with relapsed B-NHL.

Pharmacology of cytotoxic agents: a helpful tool for building dose adjustment guidelines in the elderly

Aging is associated with multidimensional changes, including alterations in physiological functions, co-morbidities and poly-medications. These changes may lead to modifications in the absorption, distribution, metabolism and excretion of drugs. The lack of a scientific basis for optimal drug dosing in the elderly is a major problem. The development and validation of guidelines are therefore essential to improve treatment administration and monitoring in elderly patients. Even though it has been widely demonstrated that standard therapies used in adults may be of great benefit in the elderly, there may be a higher incidence of toxicity. This could be avoided by using dosage individualization based on a sound knowledge of the physiological factors implicated in the pharmacokinetic (PK) characteristics of the drugs administered and in their observed pharmacodynamic (PD) effects in each patient. The so-called "population modeling" approach renders such studies feasible by allowing the analysis of PK-PD relationships from sparse observational data.

Multiple malignant tumours in the elderly

Aging of the population and technical improvements may contribute to increase the possibility of multiple malignant tumours to be diagnosed. Over a period of 18 years, 2,749 consecutive autopsies of elderly patients were performed. In addition to macroscopic examination of every single organ, bone marrow and prostate were routinely stained and microscopically examined. One hundred and sixty-seven patients with multiple malignant tumours were found. Mean age was 81.1 years for females and 80.1 years for males. Mean interval between tumours was 2.4 years for females and 1.0 year for males. First tumours were most of the time diagnosed clinically (n = 121 vs. 46) whereas second tumours were diagnosed at autopsy (n = 121 vs. 46). Origin and metastastic sites of tumours were not different between the first and second tumour. Prostate and breast were the most frequent organs involved in males and females. Multiple malignant tumours in the elderly are not rare and the second tumour is frequently diagnosed after death despite occurring relatively soon after the diagnosis of the first tumour. Multiple malignant tumours may represent a significant clinical challenge leading to further diagnostic procedures and differentiated therapeutic approaches.

Efficacy of high-dose therapy and autologous hematopoietic stem cell transplantation for non-Hodgkin's lymphoma in adults 60 years of age and older

High-dose therapy (HDT) with autologous stem cell transplantation (ASCT) is the optimal treatment for patients with relapsed aggressive non-Hodgkin's lymphoma (NHL). HDT, however, is often reserved for relatively younger patients due to limited data in older adults. We treated 53 patients aged 60 years and older (median age 62 years, range 60.3-67.7 years) with HDT and ASCT for NHL at our centers. Forty-four patients (83%) had aggressive histology, 75% had chemosensitive disease and all had failed anthracycline therapy. Conditioning regimens included busulfan, melphalan, and thiotepa (45%); cyclophosphamide (CY), etoposide (VP-16), and total body irradiation (TBI) (30%); CY and TBI (15%); and other regimens (10%). Estimated 4-year overall survival (OS), progression-free survival, and treatment-related mortality (TRM) were 33%, 24% and 22%, respectively. A multivariable analysis demonstrated that patients with chemosensitive disease (P = 0.03) and < or =3 prior regimens (P = 0.03) had superior survival. Four-year OS in patients with chemosensitive disease was 39% vs 15% in patients with chemoresistant disease. Reduced TRM was associated with the CY, VP-16 and TBI regimen (P = 0.02). HDT therapy with ASCT may result in prolonged survival and potential cure for about a quarter of elderly patients, and for almost 40% with chemosensitive disease. Optimal conditioning regimen selection may further improve outcome by reducing TRM. Age alone should not be used to exclude patients from receiving myeloablative therapy with ASCT.

Cancer chemotherapy in the elderly

As the geriatric population is growing, it is increasingly important to be familiar with chemotherapy for the elderly. Age-related changes in pharmacokinetics are documented for doxorubicin, etoposide, ifosfamide, daunorubicin, mitomycin, cisplatin and methotrexate. The hematological toxicity of most standard-dose chemotherapy is not affected by age in patients with normal organic functions and good performance status, although increased toxicity with aging is suggested in the use of actinomycin-D, etoposide, vinblastin, methotrexate, methyl-CCNU, doxorubicin and mitomycin, and in dose-intensive chemotherapy. Among non-hematological toxicities, only doxorubicin-induced cardiomyopathy and bleomycin-induced pulmonary toxicity are demonstrated to be accelerated in the elderly. There is no evidence that advanced age decreases the efficacy of chemotherapy for tumors, except for Hodgkin's disease and acute leukemia. These results suggest that advanced chronological age alone is not always associated with severe toxicity and poor prognosis, and that many elderly patients with cancer will benefit from chemotherapy. To answer questions regarding the optimal chemotherapy regimen, dose and intensity in this population, the influence of age should be analyzed in a multivariate approach in future studies.

The role of radiation therapy in the treatment of colorectal cancer. Implications for the older patient

Radiation therapy plays an important role in the treatment of patients with colorectal cancer. Randomized trials show that patients with rectal cancer have an 8% improved local control rate with postoperative radiation and an 11-13% improved local control rate with combined postoperative radiation and chemotherapy. Survival is also improved for these patients. Ongoing randomized trials may clarify the role of postoperative radiation therapy for patients with colon cancer. Although there is little specific information regarding the tolerance and response of the older patient to radiation therapy, there is no reason to believe that cancer in the older patient is more sensitive to ionizing radiation. Therefore, treatment decisions should be based on the available data. The older patient may be at an increased risk for radiation-related small bowel damage, and the clinician should pay particular attention to techniques to limit the amount of small bowel in the irradiated field.

Etoposide in the treatment of elderly/poor-prognosis patients with small-cell lung cancer

Survival rates for cancer have improved in recent decades, specifically for younger patients. However for those over 65, who account for over half of all cancer patients, mortality rates remain poor. In those with small-cell lung cancer the achievement of cure is possible in only a minority (5-10%). For the elderly and those with extensive disease we have found that the use of oral etoposide offers similar survival rates to more intensive regimens, with minimal side effects and hospitalisation. Thus the expansion of the elderly population mandates for more specific chemotherapeutic approaches in this group.