Dados do Trabalho

Título

CLINICAL IMPACT OF MONOCLONAL ANTIBODY USE IN METASTATIC COLORECTAL CANCER PATIENTS TREATED IN A BRAZILIAN PUBLIC HOSPITAL CANCER CENTER

Introdução

Monoclonal antibodies (MABs) targeting tumor angiogenic and epithelial growth factor receptor pathways have improved survival in metastatic colorectal cancer (mCRC). While strategies evaluating individualization of MABs to optimize survival in mCRC remain a motive of clinical investigation, patients (pts) submitted to institutional protocols, such as those in public hospital cancer centers, are being exposed to MABs in a pre-determined fashion.

Objetivo

Analyze the clinical impact of MABs in mCRC pts undergoing an institutional protocol, consisting of bevacizumab (B) on the first-line setting and cetuximab (C) on the third-line setting.

Método

This retrospective single-center study included mCRC pts from 2013 to 2020 who were not eligible for metastasectomy and underwent chemotherapy with or without MABs. Kaplan Meier curves and log-rank tests were used to evaluate overall survival (OS) and progression-free survival (PFS) in pts who underwent B or C in the overall population and the subgroups according to tumor laterality.

Resultado

Among 229 mCRC pts included for analysis, 89 (38.89%) were all-RAS wild-type (WT), and 51 (22.56%) were right-sided. Sixty-seven pts underwent B, with a median of 15 cycles. Twenty-one pts underwent C, which comprises 23.59% of the WT population, with a median of 6 cycles. WT patients not administrated C either had evolved with a compromised performance status or died after the second line of treatment.
B use was only associated with a significant improvement in PFS (p .026) but not in OS (p .588). Although C use was not associated with a significant improvement in OS (p .023), a pattern of an initial separation between curves, followed by a rapid decrease in survival, was noticed among pts undergoing C. Right-sided pts who underwent B had a worse OS (p .033) but no difference in PFS (p .758). In contrast, left-sided pts who underwent B had no difference in OS (p .172) but a better PFS (p .08). Pts receiving C in the third-line setting did not have significant OS benefit regardless of laterality.

Conclusão

In our cohort, B and C use does not associate with a significantly better OS. Notably, several pts with all-RAS wild-type were not exposed to C owing to performance status or death after second-line. Studies that evaluate the line-setting of MABs administration and laterality can be important to optimize benefits in public centers protocoling MABs in mCRC.

Palavras-chave

colorectal cancer, metastatic, monoclonal antibodies