Early tumor shrinkage in metastatic colorectal cancer: Retrospective analysis from an irinotecan‐based randomized first‐line trial

Abstract

Early tumor shrinkage (ETS) has been highlighted as a favorable prognostic factor related to progression-free survival (PFS) and overall survival (OS) in cytotoxic treatment of metastatic colorectal cancer. Data from a randomized phase III study comparing infusional 5-fluorouracil plus irinotecan (FUFIRI) versus irinotecan plus oxaliplatin (mIROX) were evaluated. Patient groups were analyzed according to the relative change in maximum tumor diameter between baseline and after 7 weeks of treatment. The ETS cohort was defined as a decrease of ≥20%. Additionally, the non-ETS cohort was subdivided into "minor shrinkage" (0-19%), "tumor progression" (any increase) and development of "new metastatic lesions". Progression-free survival and OS were estimated in all patient subgroups. Assessment of ETS was possible in 201 patients. Early tumor shrinkage was observed in 47% (94 ⁄ 201) and non-ETS in 53% (107 ⁄ 201) of patients. Patients with ETS had a more favorable outcome with regard to PFS (9.9 months vs 6.1 months, P = 0.029) and OS (27.5 months vs 17.8 months, P = 0.002). In the non-ETS subgroups, patients with "minor shrinkage" (PFS 8.4 months, OS 21.6 months) showed a markedly better outcome than patients with "early tumor progression" (PFS 4.0 months, OS 15.3 months) or with "new metastatic lesions (PFS 2.2 months, OS 7.6 months). In conclusion, ETS assessment offers accelerated response evaluation when compared to RECIST. In patients treated with chemotherapy alone, ETS ≥20% is associated with excellent outcome. Non-ETS is a heterogeneous subgroup where patients with minor shrinkage clearly benefit from treatment, and patients with early progression or development of new lesions have an unfavorable prognosis. (Cancer Sci 2013; 104: 718-724)

Role of depth of response and MTHFR genotype as predictors of fluorouracil rechallenge therapy for refractory metastatic colorectal cancer

“…ETS and DoR have been demonstrated to be associated with OS and PFS in several previous studies (18,19,44,45). In the present study, the majority of patients were treated with conventional chemotherapy to evaluate ETS and DoR as prognostic markers when using targeted agents, unlike previous studies.…”

Early tumour response as a survival predictor in previously- treated patients receiving triplet hepatic artery infusion and intravenous cetuximab for unresectable liver metastases from wild-type KRAS colorectal cancer

“…Statistically significant longer PFS and OS have been reported in patients with early tumor shrinkage ≥ 20% as compared to those without early shrinkage in several studies [24][25][26][27][28]. Early response was here associated with a non-statistically significant PFS prolongation by 2 months as compared to non-early response.…”

“…In the same way, no significant association was found here between overall best objective response and complete macroscopic liver resection. Recent retrospective studies [12,13,24,25] have addressed this issue through considering early tumor shrinkage as a better indicator of more stringent efficacy outcomes. They defined early tumor response as a relative change of ≥ 20% in the sum of the largest diameters of target lesions at nearly 8 weeks compared to baseline.…”

A Case of Krukenberg Tumor Metastasized from Colon Cancer Subsequent to Synchronous Multiple Liver Metastasis

“…1B , leading to a complete response that was maintained with chemotherapy. Giessen et al 9 de ned ETS as a ≥ 20 decrease in the maximum tumor diameter between the baseline and 7 weeks of treatment and found that patients with ETS had a more favorable outcome in terms of progression-free survival PFS 9.9 months vs. 6.1 months, P 0.029 and overall survival OS 27.5 months vs. 17.8 months, P 0.002 . Modest et al 10 observed ETS according to the above de nition in 59 of patients with KRAS wild-type tumors and indicated that these patients exhibited increases in their overall response rate 82 vs. 19 , P 0.001 , as well as PFS 8.9 months vs. 4.7 months, P 0.001 and OS 31.6 months vs. 15.8 months, P 0.005 .…”