In Colorectal Cancer, Treatment Efficacy Is High Among the Elderly

Caroline Helwick

July 2012, Vol 3, No 5 - AMCP Annual Meeting

San Francisco, CA—The vast majority of published evidence indicates that the relative treatment effect of chemotherapy for stage III colon cancer is as good for elderly patients as it is for younger ones, according to a systematic literature review by Anna Hung, a student in the program, and C. Daniel Mullins, PhD, Professor, Pharmacoeconomics, Pharmaceutical Health Services Research Department, Associate Director, Center on Drugs and Public Policy. The study was presented at the 2012 Academy of Managed Care Pharmacy annual meeting.

The effectiveness of chemotherapy in clinical practice may vary from the efficacy demonstrated in clinical trials, particularly for populations that are underrepresented in clinical trials, such as the elderly, Ms Hung noted. “There is limited evidence regarding how chemotherapy impacts the prognosis of elderly patients compared to nonelderly patients.”

The study synthesized the available evidence and examined the relative effectiveness of chemotherapy for stage III colon cancer among elderly versus nonelderly patients through a systematic review of the literature from 2001 to 2011, using the Agency for Healthcare Research and Quality approach.

A total of 24 articles met the eligibility criteria, which were: patients were treated for stage III colon cancer with a chemotherapy treatment recommended by the National Comprehensive Cancer Network guidelines; studies were clinical trials phase 2, 3, or 4, or observational studies with empirical analyses; studies examined the effectiveness of chemotherapy; studies included patients aged >65 years.

The chemotherapy regimens evaluated included FOLFOX (5-fluorouracil [FU], leucovorin, oxaliplatin); CapeOx (capecitabine plus oxaliplatin); cape – citabine alone; 5-FU/leucovorin; irinotecan-based treatment with or without 5-FU/leucovorin or capecitabine; bevacizumab with or without 5-FU and oxaliplatin; and multiple regimens based on 5-FU with or without irinotecan, oxaliplatin, bevacizumab, or cetuximab.

Among 13 studies that reported overall survival (OS) data, the OS was similar between elderly (aged ≥70 years) and nonelderly (aged <70 years) patients; only 3 studies reported lower OS in the elderly, 2 that evaluated 5- FU/leucovorin and 1 that evaluated multiple chemotherapy regimens.

Disease-free survival, time to progression (TTP), and overall response rates (ORRs) were also similar; one sample reported higher TTP and ORR among the elderly.

Adverse event rates were similar overall, with a few exceptions. When studies reported higher adverse event rates among elderly patients, the greater toxicities included fatigue, diarrhea, and neutropenia. There were no reports of higher rates for pain, hand-foot syndrome, stomatitis, neuropathy, or nausea and vomiting.

“Chemotherapy has similar relative effectiveness and safety outcomes in elderly versus nonelderly patients,” Ms Hung noted.

Furthermore, she noted that the findings do not support the concept that elderly patients have lower rates of chemotherapy use.