The impact of age on first-line systemic therapy in patients with metachronous metastases from colorectal cancer.

Objectives: The paucity of evidence for the optimal use of systemic therapy in elderly patients with metastatic colorectal cancer (mCRC) poses significant challenges to cancer specialists. The present population-based study provides insight into the impact of age on palliative systemic therapy in patients with metachronous metastases from CRC, in order to optimize the decision-making process.

Methods: Data on the development and treatment of metachronous metastases were collected for patients with primary resected CRC diagnosed between 2003 and 2008 in the Eindhoven area of the Netherlands Cancer Registry. Patients undergoing surgery for metastases were excluded, resulting in a study population treated with palliative intent, with or without systemic therapy (n=746).

Results: 385 patients received palliative systemic therapy (52%). Patients aged ≥75years were less likely to receive systemic therapy (31% ≥75years vs 73% <60years) and more likely to receive single-agent chemotherapy than combination-chemotherapy. Elderly patients (≥75years) treated with capecitabine-oxaliplatin (CAPOX) received fewer cycles (51% ≤3 oxaliplatin cycles, 43% ≤3 capecitabine cycles) and lower cumulative dosages compared to patients aged <75years, although initial dosages were similar. If capecitabine monotherapy (CapMono) was administered, starting dosages were 2414mg/m/d<75years and 1992mg/m/d≥75years (p<0.05), but no differences in number of received cycles or cumulative dosages were observed.

Conclusion: Age beginning at 75years significantly influenced palliative systemic therapy. Even in selected elderly patients, first-line treatment with CAPOX was associated with less cycles and lower cumulative dosages compared to younger patients. With single-agent fluoropyrimidine therapy, however, no such results were observed.