Clinical Implications of Decreased Computed Tomography Value after Ramucirumab in Advanced Gastric Cancer

This study aimed to evaluate whether a decrease of computed tomography (CT) value for tumors serves as a predictive marker in patients with advanced gastric cancer (aGC) who have undergone chemotherapy with vascular epithelial growth factor receptor 2 inhibitor (ramucirumab).

We retrospectively analyzed 44 patients with aGC who received taxane alone (TAX arm; n = 33), ramucirumab alone, or ramucirumab in combination with taxane (RAM arm; n = 11) as second-line or later chemotherapy between July 2010 and October 2016. In all patients, tumor size and tumor CT value were evaluated at two timepoints: pretreatment and first evaluation. We calculated the change of the tumors' CT value. The associations of these factors with tumor response, progression-free survival (PFS), and overall survival were investigated.

Ten (90.9%) of 11 patients in the RAM arm and 18 (54.5%) of 33 patients in the TAX arm showed decreased CT values. The rate of CT value change in the RAM arm (median -32.80%, range -53.63 to 6.84%) was higher than that in the TAX arm (median -0.44%, range -37.47 to 40.64%; p = 0.0005). When using the median value of CT value change as a cut-off, PFS was significantly longer in patients with a high rate of CT value change (decrease ≥32.80%) than in those with a low rate (decrease <32.80%) in the RAM arm (median 292 and 112 days; p = 0.045), while no significant difference of this kind was found in the TAX arm (median 91 and 125 days; p = 0.45).

Patients with aGC treated with ramucirumab experienced a significant decrease of CT value of tumors and had an association between the rate of CT value change and PFS. Our study suggests that CT value changes of tumors may be a predictor for the efficacy of ramucirumab in aGC.