Impact of tumor growth rate during preceding treatment on tumor response to nivolumab or irinotecan in advanced gastric cancer
Kazuaki Kato, Toshiki Masuishi, Kunihiro Fushiki, Shintaro Nakano, Yasuyuki Kawamoto, Yukiya Narita, Takahiro Tsushima, Kazuaki Harada, Shigenori Kadowaki, Akiko Todaka, Satoshi Yuki, Masahiro Tajika, Nozomu Machida, Yoshito Komatsu, Hirofumi Yasui, Kei Muro, Takeshi Kawakami
Abstract
•NIVO and IRI are standard treatments for refractory AGC, although it is unclear which should be administered first.•TGR may be useful for drug selection, therefore we evaluated the association between TGR and the tumor response to NIVO or IRI.•In the Slow group, the response rate (RR) was significantly higher in patients treated with NIVO compared with IRI.•In the Rapid group, there was no significant difference in RR between the NIVO and IRI groups.•TGR and NL emergence during preceding treatment may be useful for drug selection. BackgroundNivolumab (NIVO) and irinotecan (IRI) are standard treatments for refractory advanced gastric cancer (AGC); however, it is unclear which drug should be administered first or in which cases. The tumor growth rate (TGR) during preceding treatment is reported to be associated with tumor response in metastatic colorectal cancer patients treated with regorafenib or trifluridine/tipiracil, suggesting that TGR may be useful for drug selection. Therefore, we evaluated the association between TGR during preceding treatment and the tumor response to NIVO or IRI.Patients and methodsWe retrospectively evaluated consecutive AGC patients treated with NIVO or IRI and divided them into slow-growing (Slow) and rapid-growing (Rapid) groups according to TGR and the presence or absence of new lesions (NL+/NL−, respectively) during preceding treatment (Slow group: NL− with low TGR <0.30%/day; Rapid group: NL+ or high TGR ≥0.30%/day).ResultsA total of 117 patients (Rapid/Slow groups, 72/45; NIVO/IRI groups, 32/85) were eligible. All baseline characteristics except peritoneal metastases were similar between patients treated with NIVO and IRI in the Rapid and Slow groups. The response rate was significantly higher in patients treated with NIVO compared with IRI [31%/3%; odds ratio (OR), 13.8; P = 0.01; adjusted OR, 52; P = 0.002] in the Slow group, but there was no difference between patients treated with NIVO and IRI (5%/8%; OR, 0.68; P = 0.73; adjusted OR, 0.94; P = 0.96) in the Rapid group. Disease control rate, progression-free survival, and overall survival were consistent with these results.ConclusionsOur findings suggest that NIVO treatment is a more favorable option for patients with slow-growing tumors, and NIVO and IRI are similarly recommended for patients with rapid-growing tumors in refractory AGC. TGR and NL emergence during preceding treatment may be helpful for drug selection and warrant further investigation. Nivolumab (NIVO) and irinotecan (IRI) are standard treatments for refractory advanced gastric cancer (AGC); however, it is unclear which drug should be administered first or in which cases. The tumor growth rate (TGR) during preceding treatment is reported to be associated with tumor response in metastatic colorectal cancer patients treated with regorafenib or trifluridine/tipiracil, suggesting that TGR may be useful for drug selection. Therefore, we evaluated the association between TGR during preceding treatment and the tumor response to NIVO or IRI. We retrospectively evaluated consecutive AGC patients treated with NIVO or IRI and divided them into slow-growing (Slow) and rapid-growing (Rapid) groups according to TGR and the presence or absence of new lesions (NL+/NL−, respectively) during preceding treatment (Slow group: NL− with low TGR <0.30%/day; Rapid group: NL+ or high TGR ≥0.30%/day). A total of 117 patients (Rapid/Slow groups, 72/45; NIVO/IRI groups, 32/85) were eligible. All baseline characteristics except peritoneal metastases were similar between patients treated with NIVO and IRI in the Rapid and Slow groups. The response rate was significantly higher in patients treated with NIVO compared with IRI [31%/3%; odds ratio (OR), 13.8; P = 0.01; adjusted OR, 52; P = 0.002] in the Slow group, but there was no difference between patients treated with NIVO and IRI (5%/8%; OR, 0.68; P = 0.73; adjusted OR, 0.94; P = 0.96) in the Rapid group. Disease control rate, progression-free survival, and overall survival were consistent with these results. Our findings suggest that NIVO treatment is a more favorable option for patients with slow-growing tumors, and NIVO and IRI are similarly recommended for patients with rapid-growing tumors in refractory AGC. TGR and NL emergence during preceding treatment may be helpful for drug selection and warrant further investigation.