533P - First-line treatment in older patients with metastatic colorectal cancer: A large real-world study

Background

Treatment strategies in older patients with metastatic colorectal cancer (mCRC) are still a matter of debate. The aim of this study was to analyze survival outcomes according to first-line treatments and factors associated with toxicity-related interruption.

Methods

Older mCRC pts were retrospectively analyzed from 14 Italian Centers. Determinants of toxicity-related interruption were analyzed with logistic regression. Prediction of progression-free survival (PFS) was analyzed by log-rank test.

Results

Overall, 1678 older patients deemed eligible; 18% were hospitalized with a median length of stay of 12 days. Among them, 438 (38%) patients received a geriatric assessment at diagnosis of metastatic disease. Older age was not significantly associated with lower survival outcomes (mPFS <75y 23.9 mo; 75-80y 21.3 mo; >80y 21.34 mo; P=0.61) neither with toxicity-related interruption. The modified G8 score (OR 1.48, 95% C.I. 1.07-2.05, P=.017), mono-CT (OR 2.58, 95% C.I. 1.61-4.14, P<.0001) and doublet-CT (OR 2.37, 95% C.I. 1.49-3.76, P<.0001) without biologic were associated with higher probabilities of toxicity-related interruption compared to CT plus biologic. Chemotherapy alone did not significantly impact on PFS (mono-CT HR 2.38, 95% C.I. 1.49-3.82; P<.0001; doublet-CT HR 2.18, 95% C.I. 1.40-3.41, P=0.001) compared to addition of biological agents. In particular, the choice of monoCT predicted lower probability of receiving II line treatment (OR 0.58, 95% C.I. 0.39-0.87, P=.009).

Conclusions

This large real-world study evaluated first-line treatment for older CRC pts in the daily clinical practice, showing that older age is not the main variable impacting first-line choice. While, a comprehensive pts’ evaluation to estimate chemotherapy toxicity risk could help clinicians in deciding which is the most safe and effective treatment. Remarkably, the use of chemotherapy alone was associated with a higher of toxicities, with no benefit on PFS compared to chemotherapy plus biologic.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

F. Bergamo: Financial Interests, Personal, Invited Speaker: Lilly, BMS, MSD, EISAI, Bayer, Amgen; Financial Interests, Personal, Advisory Board: Servier, AAA; Other, congress: Bayer, Ipsen, AAA. F. Pietrantonio: Financial Interests, Personal, Advisory Board: AMGEN, Merck-Serono, MSD, Bayer, Astellas, Takeda, Ipsen, GSK, Johnson&Johnson, Rottapharm; Financial Interests, Personal, Invited Speaker: AMGEN, Merck-Serono, BMS, Lilly, Servier, Bayer, Pierre-Fabre, AstraZeneca, Astellas, Daiichi Sankyo, Takeda; Financial Interests, Institutional, Research Grant: BMS, AstraZeneca, Incyte, Agenus; Financial Interests, Institutional, Coordinating PI: Lilly, Amgen. All other authors have declared no conflicts of interest.