Survival of elderly Medicare patients after standard chemotherapy for advanced lung and gastrointestinal cancers in the real world.

Abstract

1605 Background: Elderly cancer patients are under-represented on clinical trials that determine standards of treatment, thus survival of such patients following standard treatment in the real world is not known. We describe unadjusted survivals for site, stage, and treatment-specific cohorts of elderly Medicare cancer patients who were treated in usual care settings. Methods: From SEER-Medicare data, we identified elderly Medicare patients with advanced lung or GI cancers who received specific standard chemotherapy regimens within six months of diagnosis. Of the 108,386 patients with the cancer sites and stages of interest, 39% (42,570/108,386) received some form of chemotherapy within six months of diagnosis. Only 32% (13,689/42,570) received one of the specific standard regimens we studied. Results: Median survival times and interquartile ranges (IQRs) varied according to cancer site, stage, and treatment. For 598 stage IV CRC patients on FOLFOX, the median survival was 19.4 mos (IQR 9.3-43.0); this is comparable to PRIME Study patients (19.7 mos). For 130 stage IV CRC patients on FOLFIRI, the median survival was 16.1 mos (IQR 5.6-30.0), which is lower than BICC-C Study patients (23.1 mos). For 3,815 advanced pancreatic cancer patients on gemcitabine, the median survival was 4.3 mos (IQR 2.0-8.7), which is slightly lower than CALGB 80303 patients (5.8 mos). For 8,040 stage IV NSC lung cancer patients on carboplatin and paclitaxel, the median survival was 7.0 mos (IQR 3.2-14.2); this is comparable to ECOG 1594 patients (7.8 mos). For 1,104 extensive stage SCLC patients on cisplatin and VP16, the median survival was 8.5 mos (IQR 4.7-12.9), which is slightly lower than CALGB 9732 patients (10.0 mos). Conclusions: The observed survival of cancer site, stage, and treatment-specific cohorts of elderly Medicare patients with advanced lung or GI cancers who were treated in real world settings with standard chemotherapy was, in general, similar to that of patients treated with nominally identical regimens on trials. Further analyses should explore the shorter survival for elderly Medicare patients with stage IV CRC treated with FOLFIRI in the usual care setting compared to patients treated on trials.