Dados do Trabalho

Título

BOTH ANTI-EGFR ANTIBODIES ARE SIMILARLY ACTIVE IN COMBINATION WITH IRINOTECAN IN METASTATIC COLORRETAL CANCER (MCRC) THAT HAVE PREVIOUSLY PROGRESSED ON IRINOTECAN.

Introdução

The anti-EGFR antibodies have been used either in combination or monotherapy for mCRC. Previous studies have demonstrated that the tumor resistance to irinotecan could be reversed by the addition of cetuximab. However, there is no data regarding the combination with panitumumab.

Objetivo

The present study aims to assess the activity of the combination of irinotecan with anti-EGFR antibodies in patients previously treated with Irinotecan monotherapy.

Método

This is a retrospective single-institutional cohort analyzing data from mCRC patients who presented radiologic progression on irinotecan (for at least one dose) and were subsequently treated with the combination of anti-EGFR plus irinotecan from July 2008 to April 2018. The primary endpoint was response rate accessed by RECIST 1.1. As a secondary endpoint, tumor response according on the primary tumor sidedness was evaluated.

Resultado

From a total of 586 patients, we identified 460 patients with mCRC the fulfilled inclusion criteria. All patients were treated with a combination of Irinotecan and anti-EGFR targeting antibodies for at least one cycle (D1 and D15) after disease progression on irinotecan. One hundred eighty-three (183) patients received Irinotecan with cetuximab (I+C) and 277 received Irinotecan with panitumumab (I+P). Median age was 55.9 years (range, 19 - 83 years), with a male to female ratio of 1.3:1. Approximately 73.5% were diagnosed with a histologically moderately differentiated grade tumor. Regarding the study’s primary endpoint, partial response occurred in 22.6% of patients [23.5% for (I+C) and 22.0% for (I+P)], and 25,2% had stable disease [27.8% for (I+C) and 23.6% for (I+P)]. Interestingly, patients with ride-sided tumors presented partial response in 3.3% in the I+C regimen and 14.3% in the I+P regimen. Patients presented a median survival time of 29.3 months (95% CI. 25.9 to 32.7) and 28.9 months (95% CI. 27.5 to 30.2) months, p = 0,283, in the I+C and I+P, respectively. The disease control rate was 50.3% in the I + C combination and 45.7% in the I + P combination (p = 0.358).

Conclusão

Both combinations appear to be active in reversing irinotecan resistance, with a favorable trend in right-sided tumors treated with the panitumumab combination. Further confirmatory studies with a larger series of patients are warranted.

Palavras-chave

metastatic colorectal cancer; anti-EGFR; irinotecan; sidedness

Área

Oncologia - Tumores TGI Inferior (cólon/reto/ânus)