The number of medications used by older patients with cancer in the 6 months before initiating IV chemotherapy is predictive of their posttreatment risk for inpatient hospitalization. These results were published in the Journal of Geriatric Oncology.
Issues such as comorbid conditions, cognitive impairment, frailty, vision and/or hearing loss, malnutrition, and polypharmacy tend to complicate cancer care in patients aged 65 and older. Polypharmacy is defined as taking 5 or more medications; an estimated 48% to 80% of older patients with cancer have multiple comorbidities that require pharmacologic management.
Polypharmacy increases the risks for drug–drug interactions, adverse drug events, health care cost, and resource use. However, despite projections that by the year 2040 73% of all cancer survivors will be older than 65, little is known about how to manage cancer treatment in these patients. Therefore, a team of researchers at Thomas Jefferson University in Philadelphia, Pennsylvania, investigated the effects of polypharmacy during the 6 months prior to initiating IV chemotherapy for cancer on inpatient hospitalization among older patients with cancer.
For the study, the researchers identified a total of 13,959 patients aged 65 and older with prostate, breast, or lung cancer from the Surveillance, Epidemiology, and End Results (SEER)-Medicare files. Cancer diagnoses were made between 1991 and 2013, and patients were treated with IV chemotherapy between 2011 and 2014. The researchers used negative binomial models to assess the association between polypharmacy and postchemotherapy inpatient hospitalizations, which were presented as incidence rate ratios. The endpoint was total number of inpatient hospital admissions divided by the total time at risk, defined as the total time alive in the 6-month period from chemotherapy initiation minus the time spent in the hospital.
Risk for drug–drug interactions increase from 13% for patients taking 2 concurrent medications to almost 100% for patients taking 8 or more medications, including prescription, over-the-counter, and supplements of any kind. Among the patients selected for this study, those with lung cancer were taking a median of 11 medications during the 6-month period prior to treatment, those with prostate cancer were taking 10 medications, and those with breast cancer were taking 9 medications.
The increase in hospitalization rate was relative to the number of concurrent medications patients were taking in the 6 months prior to IV chemotherapy compared with patients who were taking fewer than 5 medications in the same period. Among patients with prostate cancer, hospitalization rates were 42% higher among those taking 5 to 9 concurrent medications, 75% higher among those taking 10 to 14 medications, and 114% higher among those taking 15 or more medications.
Compared with patients taking 5 or fewer concurrent medications, hospitalization rates were 36%, 49%, and 82% higher for patients with lung cancer taking 5 to 9, 10 to 14, and 15 or more concurrent medications, respectively. Among those with breast cancer, hospitalization rates were 17%, 61%, and 101% higher, respectively.
Chemotherapy treatments are often based on data from clinical trials that exclude patients with multiple comorbidities, the study authors explained. “A logical next step would be to conduct a prospective randomized controlled trial to determine whether improved medication management can reduce inpatient hospitalization and other healthcare resource utilization among older adults treated with chemotherapy,” the authors concluded.
Lu-Yao G, Nightingale G, Nikita N, et al. Relationship between polypharmacy and inpatient hospitalization among older adults with cancer treated with intravenous chemotherapy [published online March 18, 2020]. J Geriatr Oncol. doi: 10.1016/j.jgo.2020.03.001