Factors influencing treatment with chemotherapy

Performance status.More patients with ED SCLC have greatly impaired performance status at the time of diagnosis than patients with LD. Such patients have a poor prognosis and tolerate aggressive chemotherapy or combined-modality therapy poorly. Single-agent intravenous, oral, and low-dose biweekly regimens have been developed for these patients.[33,38-44]Prospective randomized studies have shown that patients with a poor prognosis who are treated with conventional regimens live longer than those treated with single-agent, low-dose regimens or abbreviated courses of therapy. A study comparing chemotherapy every 3 weeks with treatment given as required for symptom control showed an improvement in QOL in patients receiving regular treatment.[41][Level of evidence B1]Other studies have tested intensive one-drug or two-drug regimens. A study conducted by the Medical Research Council demonstrated similar efficacy for an etoposide-plus-vincristine regimen and a four-drug regimen.[42] The latter regimen was associated with a greater risk of toxic effects and early death but was superior with respect to palliation of symptoms and psychological distress.[42][Level of evidence A3] Studies comparing a convenient oral treatment with single-agent oral etoposide versus combination therapy showed that the overall response rate and OS were significantly worse in the oral etoposide arm.[38,43][Level of evidence A1]

Age.Subgroup analyses of phase II and III trials of patients with SCLC by age showed that myelosuppression and doxorubicin-induced cardiac toxic effects were more severe in older patients than in younger patients, and that the incidence of treatment-related death tended to be higher in older patients.[44] About 80% of older patients, however, received optimal treatment, and their survival was comparable with that of younger patients. The standard chemotherapy regimens for the general population could be applied to older patients in good general condition (i.e., performance status of 0–1, normal organ function, and no comorbidity). There is no evidence of a difference in response rate, disease-free survival (DFS), or OS in older patients compared with younger patients.