Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
Copyright © 2022 by the Korean Cancer Association
This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Ethical Statement
This study was approved by the Institutional Review Board (IRB) of Asan Medical Center, Korea (approval number: 2021-1489), and the study was conducted according to the principles of the Helsinki declaration. Due to the nature of this retrospective study, the requirement of obtaining informed consent was waived by the IRB.
Author Contributions
Conceived and designed the analysis: Kang YK.
Collected the data: Ryu MH, Bang YH, Kim HD, Lee HE, Kang YK.
Contributed data or analysis tools: Kang S, Ryu MH, Bang YH, Kim HD, Kang YK.
Performed the analysis: Kang S, Ryu MH, Kim HD, Lee HE, Kang YK.
Wrote the paper: Kang S, Ryu MH, Kim HD, Kang YK.
Conflicts of Interest
Nothing directly related to this work. Outside of this work, YKK has served as a consultant for ALX Oncology, Zymeworks, Amgen, Novartis, Macrogenics, Daehwa, Blueprint, Surface Oncology, BMS, and Merck (MSD).
3 Years of imatinib (n=31) | 5 Years of imatinib (n=20) | p-value | |
---|---|---|---|
Age (yr) | |||
≤ 60 | 22 (71.0) | 12 (60.0) | 0.612 |
> 60 | 9 (29.0) | 8 (40.0) | |
Age (yr) | 58 (24–78) | 57 (26–79) | 0.992 |
Sex | |||
Male | 19 (61.3) | 15 (75.0) | 0.478 |
Female | 12 (38.7) | 5 (25.0) | |
Location of tumor | |||
Stomach | 14 (45.2) | 4 (20.0) | 0.125 |
Non-stomach | 17 (54.8) | 16 (80.0) | |
Small intestine | 16 | 15 | |
Large intestine | 0 | 1 | |
Peritoneum | 1 | 0 | |
Largest diameter of tumor (cm) | |||
≤ 5 | 0 | 2 (10.0) | 0.275 |
5.1–10 | 16 (51.6) | 9 (45.0) | |
> 10.0 | 15 (48.4) | 9 (45.0) | |
Largest diameter of tumor (cm) | 10.0 (5.2–27.0) | 10.0 (2.5–20.0) | 0.877 |
Tumor mitotic count (/50 HPFs) | |||
≤ 5 | 14 (45.2) | 8 (40.0) | 0.859 |
6–10 | 4 (12.9) | 4 (20.0) | |
> 10 | 13 (41.9) | 8 (40.0) | |
Tumor mitotic count (/50 HPFs) | 7 (1–125) | 7 (0–50) | 0.772 |
Tumor mutation type | |||
KIT exon 11 mutation | 21 (72.4) | 19 (95.0) | 0.092 |
KIT exon 9 mutation | 2 (6.9) | 1 (5.0) | |
Wild type for KIT and PDGFRA | 4 (10.8) | 0 | |
Others | 4a) (10.8) | 0 |
Treatment profile | 3 Years of imatinib (n=31) | 5 Years of imatinib (n=20) |
---|---|---|
Completion | 17 (54.8) | 12 (60.0) |
Ongoing | 8 (25.8) | 0 |
Early discontinuation | 6 (19.3) | 8 (40.0) |
Disease progression | 2 (6.5) | 0 |
Patient’s choice | 3 (9.6) | 1 (5.0) |
Adverse events | 0 | 4 (20) |
Lost to follow-up | 1 (5.4) | 1 (5.0) |
Other medical conditions | 0 | 2 (10.0)a) |
Baseline characteristics of the study patients
3 Years of imatinib (n=31) | 5 Years of imatinib (n=20) | p-value | |
---|---|---|---|
Age (yr) | |||
≤ 60 | 22 (71.0) | 12 (60.0) | 0.612 |
> 60 | 9 (29.0) | 8 (40.0) | |
Age (yr) | 58 (24–78) | 57 (26–79) | 0.992 |
Sex | |||
Male | 19 (61.3) | 15 (75.0) | 0.478 |
Female | 12 (38.7) | 5 (25.0) | |
Location of tumor | |||
Stomach | 14 (45.2) | 4 (20.0) | 0.125 |
Non-stomach | 17 (54.8) | 16 (80.0) | |
Small intestine | 16 | 15 | |
Large intestine | 0 | 1 | |
Peritoneum | 1 | 0 | |
Largest diameter of tumor (cm) | |||
≤ 5 | 0 | 2 (10.0) | 0.275 |
5.1–10 | 16 (51.6) | 9 (45.0) | |
> 10.0 | 15 (48.4) | 9 (45.0) | |
Largest diameter of tumor (cm) | 10.0 (5.2–27.0) | 10.0 (2.5–20.0) | 0.877 |
Tumor mitotic count (/50 HPFs) | |||
≤ 5 | 14 (45.2) | 8 (40.0) | 0.859 |
6–10 | 4 (12.9) | 4 (20.0) | |
> 10 | 13 (41.9) | 8 (40.0) | |
Tumor mitotic count (/50 HPFs) | 7 (1–125) | 7 (0–50) | 0.772 |
Tumor mutation type | |||
KIT exon 11 mutation | 21 (72.4) | 19 (95.0) | 0.092 |
KIT exon 9 mutation | 2 (6.9) | 1 (5.0) | |
Wild type for KIT and PDGFRA | 4 (10.8) | 0 | |
Others | 4 |
0 |
Values are presented as number (%) or median (range). HPF, high-power field.
a)KIT exon 17 mutation (n=1), not available (n=2), and undetermined (when the KIT mutation analysis revealed no mutation and PDGFRA mutation analysis was not conducted, n=1).
Comparison of the treatment profiles
Treatment profile | 3 Years of imatinib (n=31) | 5 Years of imatinib (n=20) |
---|---|---|
Completion | 17 (54.8) | 12 (60.0) |
Ongoing | 8 (25.8) | 0 |
Early discontinuation | 6 (19.3) | 8 (40.0) |
Disease progression | 2 (6.5) | 0 |
Patient’s choice | 3 (9.6) | 1 (5.0) |
Adverse events | 0 | 4 (20) |
Lost to follow-up | 1 (5.4) | 1 (5.0) |
Other medical conditions | 0 | 2 (10.0) |
Values are presented as number (%).
a)Includes sepsis related to cellulitis (n=1), postoperation complication (enterocutaneous fistula, n=1).
Univariate and multivariate analysis of recurrence-free survival
Factor Univariate analysis | Multivariate analysis | |||
---|---|---|---|---|
|
| |||
HR (95% CI) | p-value | HR (95% CI) | p-value | |
Age (yr) | ||||
| ||||
≤ 60 | Reference | |||
| ||||
> 60 | 0.97 (0.34–2.81) | 0.960 | - | - |
| ||||
Location of tumor | ||||
| ||||
Stomach | Reference | |||
| ||||
Non-stomach | 0.61 (0.21–1.74) | 0.353 | - | - |
| ||||
Largest tumor diameter (cm) | ||||
| ||||
> 10 (median) | Reference | |||
| ||||
≤ 10 | 0.87 (0.32–2.33) | 0.783 | - | - |
| ||||
Mitotic count (/50 HPFs) | ||||
| ||||
> 7 (median) | Reference | Reference | ||
| ||||
≤ 7 | 0.31 (0.11–0.89) | 0.030 | 0.20 (0.06–0.67) | 0.009 |
| ||||
Gene mutation | ||||
| ||||
Others | Reference | Reference | ||
| ||||
KIT exon 11 | 0.34 (0.1–1.12) | 0.076 | 0.38 (0.09–1.52) | 0.170 |
| ||||
Treatment duration (yr) | ||||
| ||||
3 | Reference | Reference | ||
| ||||
5 | 0.29 (0.09–1.01) | 0.052 | 0.25 (0.06–1.05) | 0.058 |
CI, confidence interval; HPF, high-power field; HR, hazard ratio.
Values are presented as number (%) or median (range). HPF, high-power field.
Values are presented as number (%). Includes sepsis related to cellulitis (n=1), postoperation complication (enterocutaneous fistula, n=1).
CI, confidence interval; HPF, high-power field; HR, hazard ratio.