Management of Colorectal Cancer in Elderly Patients

The treatment of colorectal cancer has evolved dramatically over the last 15 years. Advances in surgery, radiotherapy and chemotherapy have enabled oncologists to cure more patients and offer improved quality of life to patients not amenable to cure. Specific knowledge of colorectal cancer care of the elderly, while lagging behind the treatment of younger patients, is beginning to emerge. Informed by recent trials, the approach towards elderly patients is shifting towards more aggressive treatment and multimodal therapy. Surgeons are operating on the elderly with greater frequency, less operative mortality and greater success; 5-year survival following potentially curative surgery has risen from 50% to 67%.

Research of adjunctive therapy for colorectal cancer is enrolling more elderly patients, and with this has come an understanding of the role of chemotherapeutic agents in the treatment of the elderly, used individually and within multi-drug regimens. This research offers insight into how the elderly respond to chemotherapy, informing clinicians on anticipated benefits and toxicities of treatment. Fluorouracil-based regimens, which have long been the standard adjuvant chemotherapy, have been shown to offer benefits to the elderly compared with those not receiving adjuvant chemotherapy (71% versus 64% 5-year survival), and to cause similar toxicities as seen in younger patients. The role of novel chemotherapeutic agents in the treatment of elderly patients with colorectal cancer is also emerging, with studies finding that irinotecan, in combination with a fluorouracil-based regimen, can offer a further survival benefit of over 2 months compared with fluorouracil alone. While newer agents such as capecitabine, oxaliplatin, raltitrexed and tegafur/uracil (UFT) have been focused upon by clinical researchers, data on their use in the elderly remain unconvincing.

Not only are we approaching a clearer understanding of the effectiveness of cancer care among the elderly, but research is also beginning to identify the cost effectiveness of both standard and emerging chemotherapeutic agents. Cost effectiveness of fluorouracil-based regimens, depending on delivery strategy, use of modulating agents and stage of cancer vary from $US2000 per quality-adjusted life-year (QALY) to $US20 200 per QALY (1992 values). Irinotecan therapy has not been fully investigated from the perspective of cost effectiveness; the figure of $10 000 per QALY (1998 values) for irinotecan monotherapy over fluorouracil regimens is likely an underestimate, while cost analysis of irinotecan and fluorouracil combination therapy has not yet been reported. Our understanding of cost effectiveness of other novel agents has lagged behind; further research on these agents is needed. Nonetheless, as the effects of these novel agents upon both outcomes and costs continue to be defined, both curative and palliative treatment of colorectal cancer in the elderly patient will become more sophisticated and effective.