SAN FRANCISCO — About 38% of the patients receiving care at the VA’s healthcare system served in the military during the Vietnam War era and have an average age fast approaching 70. Korean War veterans, who still made up nearly 15% of the patient population, are even older, having served in a war that ended 68 years ago.
The advanced age of so many VA patients complicates treatment for conditions such as prostate cancer, according to recent research.
For example, a study from the San Francisco VAMC and the University of California San Francisco found that, in a vulnerable population of older patients with localized prostate cancer, radiation was associated with a decline in functional independence. “Patients with higher comorbidity experienced more severe functional decline within the first 3 months of radiation therapy. In all comorbidity levels, functional status had not returned to baseline by six months,” the authors wrote in the Journal of Geriatric Oncology.
Those findings were based on a retrospective cohort study including veterans age 65 and older with localized prostate cancer who resided in a VA nursing facility while receiving prostate radiation from 2005 to 2015. Researchers evaluated the change in Minimum Data Set (MDS) activities of daily living (ADL) score during six months from the start of treatment. Because prior studies have shown the authors explained, Charlson Comorbidity Index (CCI) to be a strong predictor of treatment-related toxicity, analysis included interaction with CCI.
Included were 487 patients with a median age of 73. Results indicated that, for the average patients in the cohort, the predicted MDS-ADL score worsened from 2.9 (95% CI 2.4-3.6) at the start of radiation to 3.8 (95% CI 3.1-4.8) at three months and then 4.5 (95% CI 3.5-5.7) by the sixth month.
“Patients with greater comorbidity (CCI ≥ 4) had worse functional outcomes in months 0-3 compared to patients with less comorbidity (CCI 0-3),” the authors advised. “MDS-ADL score worsened by 1.9 in the CCI ≥4 patients compared to 0.3 in the CCI 0-3 group. During months three-six, patients in both Charlson groups experienced similar worsening of MDS-ADL score.”
Researchers cautioned that, in a vulnerable population of older patients with localized prostate cancer, radiation was associated with a decline in functional independence in the older patients with localized prostate cancer, adding that, at all comorbidity levels, functional status had not returned to baseline by six months.
Another study, published in Drugs & Aging, pointed out that prostate cancer is especially common in older patients, because the risk of developing the condition increases with age.
“Cancer therapy brings unique challenges in older patients, as this population is vulnerable to many side effects and drug interactions, and they have varying degrees of frailty, which may limit the use of these therapies,” wrote authors from Oregon Health & Science University and the VA Portland, OR, Healthcare System. “The US FDA has recently approved several novel next-generation hormonal therapies for patients with various stages of prostate cancer, giving patients more treatment options. These therapies (e.g., apalutamide, enzalutamide, darolutamide and abiraterone) have unique side effects that the practitioner must consider when evaluating therapeutic treatments in any patient, and these side effects also affect older patients differently.”
The authors reviewed the mechanism of action and metabolism of the next-generation hormonal therapies and reported efficacy and safety data from trials of these agents in nonmetastatic castration-resistant prostate cancer, metastatic hormone-sensitive prostate cancer and metastatic castration-resistant prostate cancer.
Among the authors’ major points were that enzalutamide and apalutamide might increase the risk of falls and fractures in older patients and that abiraterone requires the concurrent use of low-dose glucocorticoids, which can lead to side effects in older patients. They emphasized that drug-drug interactions should be considered in older patients using multiple medications.
- Ursem C, Diaz-Ramirez LG, Boscardin J, Lee S. Changes in functional status associated with radiation for prostate cancer in older veterans. J Geriatr Oncol. 2020 Dec 30:S1879-4068(20)30533-6. doi: 10.1016/j.jgo.2020.12.011. Epub ahead of print. PMID: 33388282.
- Feng Z, Graff JN. Next-Generation Androgen Receptor-Signaling Inhibitors for Prostate Cancer: Considerations for Older Patients. Drugs Aging. 2021 Feb;38(2):111-123. doi: 10.1007/s40266-020-00809-3. Epub 2021 Feb 9. PMID: 33559101.
