Clinical pharmacology of chemotherapy agents in older people with cancer

Utilisation of Adjuvant Chemotherapy and 5-Year Survival Analysis of Prospectively Recorded Cohort Data for Older Adults Versus Younger Adults with Resected Primary Colon Cancer

PURPOSE

Colon cancer is predominantly a disease of older adults. Studies determining the influence of age on outcomes of colon cancer have conflicting results. We aim to determine the long-term outcomes and utilisation of adjuvant chemotherapy of older adults compared with younger adults who had had a resection of a primary colon cancer.

METHODS

Consecutive patients who had resection of a primary colon cancer between January 1, 2000 and December 31, 2010 were identified from a prospective database and stratified into three age groups: ≤ 69 years, 70 to 79 years, and ≥ 80 years. Age-related differences in patients, cancer, and treatment characteristics were determined by chi-square tests. Five-year overall survival and cancer-specific survival were determined by Kaplan-Meier method and by multivariable Cox regression analysis to adjust for potential confounding factors.

RESULTS

Of 1135 included patients, 469 (41%) patients were aged ≤ 69 years, 382 (34%) were 70-79 years, and 284 (25%) were ≥ 80 years. Increasing age group predicted more comorbidity (p < 0.001), cardiac comorbidity (p < 0.001), right-sided cancers (p < 0.001), and less adjuvant chemotherapy (stage III only; p < 0.001). Increasing age group was associated with worse overall survival by stage (p < 0.001) but not cancer-specific survival by stage (p = 0.83). Adjuvant chemotherapy in patients with stage III colon cancer independently predicted improved overall survival (p < 0.001) and cancer-specific survival (p = 0.01).

CONCLUSIONS

Compared with younger adults, older adults with colon cancer had worse survival outcomes and received less adjuvant chemotherapy.

New drugs and patient-centred end-points in old age: setting the wheels in motion

Older patients with various degrees of frailty and disability, a key population target of pharmacological interventions in acute and chronic disease states, are virtually neglected in pre-marketing studies assessing the efficacy and safety of investigational drugs. Moreover, aggressively pursuing established therapeutic targets in old age, e.g. blood pressure, serum glucose or cholesterol concentrations, is not necessarily associated with the beneficial effects, and the acceptable safety, reported in younger patient cohorts. Measures of self-reported health and functional status might represent additional, more meaningful, therapeutic end-points in the older population, particularly in patients with significant frailty and relatively short life expectancy, e.g. in the presence of cancer and/or neurodegenerative disease conditions. Strategies enhancing early knowledge about key pharmacological characteristics of investigational drugs targeting older adults are discussed, together with the rationale for incorporating non-traditional, patient-centred, end-points in this ever-increasing group.

Do we protect or discriminate? Representation of senior adults in clinical trials

AIM

The analysis of barriers responsible for low recruitment of older patients in clinical trials and presentation of possible solutions are the subject of this review.

BACKGROUND

Europe's population is ageing, and the group of people who more frequently develop neoplasms increases. Oncologists are confronted with a new challenge - how to treat cancer in this group of patients, especially considering the lack of Evidence Based Medicine (EBM) guidelines for treatment of cancer in the elderly population.

MATERIALS AND METHODS

Medline search and analysis of studies published between 1999 and 2012, containing key words: senior adults, cancer, elderly in clinical trials.

RESULTS

Detailed analysis of relevant studies demonstrated that senior adults are underrepresented in clinical trials. Moreover, there is a lack of trials exclusively designed for this heterogeneous group of patients. The analysis of reasons for low recruitment of older patients in clinical trials revealed barriers dependent on patient's and physician's attitudes as well as institutional and logistic problems.

CONCLUSIONS

It is necessary to widen the scale of trials of all phases in the group of seniors with appropriate assessment of toxicity. This will allow a proper stratification and obtaining representative groups for statistical analysis and credible trial results. Another priority is the design of trials dedicated exclusively to the elderly.