Use of palliative chemotherapy and targeted agents in elderly patients with metastatic colorectal cancer (mCRC).

Abstract

6018 Background: Elderly patients are increasingly diagnosed with advanced cancers, but they are consistently underrepresented in clinical trials, which may lead to undertreatment. Our aims were to 1) evaluate the impact of advanced age on patterns of first-line chemotherapy and bevacizumab use in mCRC, 2) examine the reasons for treatment choices and 3) compare adverse events and treatment discontinuations in elderly vs young patients. Methods: A random sample of mCRC patients diagnosed from 2006 to 2007 and referred to any 1 of 5 regional cancer centers in British Columbia, Canada was reviewed. Summary statistics were used to describe treatment patterns between the elderly (>/=70 years) and young (<70 years). Cox regression was used to determine the effect of systemic therapy on overall survival, controlling for age and confounders. Results: We identified 800 patients: 43% elderly and 57% young; 56% men; and 26 / 36 / 38% ECOG 0 / 1 / 2+, respectively. Fewer elderly patients were given chemotherapy (52% vs 79%, p<0.001). Among those treated, most common first-line palliative regimens for elderly vs young included: capecitabine (50 vs 15%), FOLFIRI (26 vs 38%), and FOLFOX (15 vs 37%) (all p<0.001). Those aged >/=70 were also less likely to receive bevacizumab in their regimens (22 vs 50%, p<0.001). The most frequent reasons for no systemic therapy were similar between age groups: patient choice (31 vs 28%), poor ECOG (16 vs 17%), and significant co-morbidity (11 vs 13%). Risk of chemotherapy (p=0.30) and bevacizumab (p=0.39) adverse events were comparable between elderly and young as were rates of early chemotherapy (p=0.07) and bevacizumab (p=0.79) discontinuation. Receipt of systemic therapy +/- bevacizumab was associated with improved survival from mCRC (HR for death 0.50, 95% CI 0.31-0.62, p<0.001), regardless of advanced age (p interaction for age and treatment = 0.33). Conclusions: Elderly patients with mCRC are more likely to receive no chemotherapy, capecitabine monotherapy, or a regimen without bevacizumab. However, in carefully selected elderly patients, adverse events, treatment discontinuations, and overall survival benefit from treatment appear similar to those observed for younger patients.