Dados do Trabalho

Título

CLINICAL IMPACT OF DE-ESCALATING CHEMOTHERAPY IN METASTATIC COLORECTAL CANCER: A REAL-WORLD ANALYSIS OF A TERTIARY CANCER CENTER

Introdução

Several clinical trials have evaluated the role of de-escalating systemic treatment in metastatic colorectal cancer (mCRC) through maintenance (M) or chemotherapy-free interval (CFI). Yet, evaluation of these strategies in a real-life setting, aside from controlled trials, remains underexplored and may contribute to clinical practice.

Objetivo

We sought to evaluate whether de-escalation of 1st line chemo in mCRC, through M or CFI, impacts survival compared to continuous chemo (CC). In addition, we aim to analyze factors that might associate with benefits upon de-escalation.

Método

This retrospective study included mCRC patients (pts) who underwent 1st line fluoropyrimidine (FP), plus either oxaliplatin or irinotecan, from 2013 to 2020. M required withdrawal of oxaliplatin or irinotecan, while CFI a complete programmed cessation of chemo. CC required at least 6 months of an FP doublet without progression.
For both M and CFI, the 1st line progression-free survival (PFS) curves were subclassified as PFS1 and PFS2 according to progression after de-escalation and FP doublet re-escalation, respectively. For CC, both PFS1 and PFS2 represented progression upon 1st line FP doublet chemo. Overall survival (OS) and PFS were analyzed using Kaplan Meier and log-rank tests. Univariate analysis and multivariate Cox proportional were performed within each treatment strategy, considering laterality, RAS status, adjuvant chemo within 12 months before recurrence, peritoneal carcinomatosis, and best RECIST response.

Resultado

Among 144 pts included, 70, 52, and 22 underwent CC, M, and CFI. When curves were analyzed altogether, no significant difference in OS was identified (p .064), but a significant difference in PFS1 (p .013) and PFS2 was met (p .039). Both C and CFI strategies were associated with an improvement in PFS1 comparing to M (p .027 and p .05, respectively). In addition, CFI had a better PFS2 comparing to C (p 021). Previous response was associated with a better PFS1 for CFI (p .035). On multivariate analysis, pts on CFI without previous adjuvant chemo and pts on M with a left-sided tumor were associated with a better PFS1 (HR 15.3 with p .02; and HR 2.8 with p .02, respectively).

Conclusão

De-escalation of 1st line chemo in mCRC was not associated with a detrimental impact on OS. Previous adjuvant chemo status, chemo response, and left-sided tumors might further contribute to select pts in whom de-escalation might associate with an improved PFS.

Palavras-chave

colorectal cancer, metastatic, chemotherapy