Table 2.
Univariate analysis for PFS (a) and OS (b) in the entire cohort of patients
| Factor | Subgroup | PFS (months) | 5-year PFS | 95 % CI | 8-year PFS | 95 % CI | p value | |
|---|---|---|---|---|---|---|---|---|
| Median | 95 % CI | |||||||
| (a) | ||||||||
| Gender | Female | 43.6 | 33.0–49.4 | 37.7 | 30.7–46.4 | 30.6 | 23.6–39.7 | 0.508 |
| Male | 34.8 | 28.4–45.2 | 36.2 | 29.6–44.2 | 24.1 | 17.7–32.6 | ||
| Age | ≤40 | 23.7 | 15.4–66.8 | 32.9 | 20.4–53.1 | 20.3 | 9.6–42.8 | 0.246 |
| >40 | 38.8 | 32.3–47.3 | 37.4 | 32.1–43.4 | 28.0 | 22.8–34.4 | ||
| The period of initiation of imatinib therapy (years) | 2001–2003 | 45.3 | 36.4–66.7 | 42.3 | 33.3–53.7 | 32.5 | 24.1–44.0 | 0.273 |
| 2004–2006 | 39.6 | 30.8–50.2 | 35.8 | 28.5–44.8 | 24.5 | 17.9–33.6 | ||
| 2007–2010 | 30.0 | 26.3–42.3 | 38.1 | 30.0–48.5 | 38.1 | 30.0–48.5 | ||
| Resection of residual disease during imatinib therapy | Yes | NA | 64.9–NA | 62.2 | 52.1–74.4 | 50.4 | 39.4–64.6 | <0.001 |
| No | 27.5 | 24.2–34.1 | 29.0 | 23.8–35.4 | 19.7 | 14.8–26.3 | ||
| Primary tumor site | Stomach | 35.5 | 7.4–38.5 | 42.1 | 33.9–52.3 | 31.8 | 23.5–43.0 | |
| Duodenum | 21.2 | 8.13–NA | 12.6 | 2.3–69.1 | 12.6 | 2.3–69.1 | 0.0002 | |
| Small bowel | 40.9 | 33.6–48.1 | 35.8 | 28.7–44.7 | 25.4 | 18.4–35.0 | ||
| Large bowel/rectum | 66.6 | 45.2–NA | 59.1 | 42.4–82.3 | 47.3 | 30.0–74.4 | ||
| Other or intraperitoneally with unknown primary origin | 15.9 | 7.4–38.5 | 15.8 | 6.6–38.1 | 11.9 | 4.2–33.8 | ||
| Presence of liver metastases at imatinib start | Yes | 40.7 | 33.2–50.9 | 37.1 | 30.5–45.1 | 23.8 | 17.6–32.2 | 0.858 |
| No | 33.0 | 27.8–45.4 | 36.7 | 29.8–45.3 | 31.3 | 24.3–40.3 | ||
| The maximal diameter of the largest tumor (mm) | ≤50 | 56.5 | 44.9–86.4 | 49.1 | 38.4–62.6 | 31.9 | 21.2–48.0 | 0.003 |
| >50–100 | 66.6 | 43.6–NA | 53.2 | 43.0–65.8 | 39.0 | 28.5–53.6 | ||
| >100 | 27.3 | 21.8–40.9 | 27.8 | 19.8–39.2 | 21.8 | 14.3–33.1 | ||
| Tumor genotype | Wild type | 20.6 | 11.5–NA | 34.0 | 19.2–60.2 | 27.2 | 13.2–55.9 | 0.005 |
| Exon 11 KIT | 47.3 | 36.4–66.6 | 41.9 | 33.5–52.5 | 31.6 | 23.1–43.2 | ||
| Exon 9 KIT | 20.9 | 14.0–38.8 | 18.6 | 7.9–43.7 | 18.6 | 7.9–43.7 | ||
| Exon 18 PDGFRA D842V | 2.3 | 1.7–NA | 22.2 | 6.5–75.4 | 22.2 | 6.5–75.4 | ||
| Other | NA | 5.2–NA | 57.1 | 30.1–100.0 | 57.1 | 30.1–100.0 | ||
| Baseline albumin level | Normal | 59.9 | 44.2–80.4 | 49.3 | 42.7–57.0 | 36.4 | 29.5–44.9 | <0.001 |
| Low | 23.7 | 19.2–34.8 | 15.4 | 7.8–30.1 | 12.8 | 6.0–27.5 | ||
| Baseline neutrophils count | Normal | 56.5 | 45.3–80.4 | 49.2 | 42.4–57.1 | 36.8 | 29.8–45.5 | <0.001 |
| High | 20.2 | 16.9–28.7 | 20.9 | 12.5–34.7 | 15.6 | 8.2–29.9 | ||
| Baseline hemoglobin level | Normal | 56.5 | 44.9–75.7 | 48.7 | 42.0–56.4 | 36.0 | 29.1–44.4 | <0.001 |
| Low | 19.4 | 15.9–26.6 | 18.0 | 9.9–32.7 | 15.0 | 7.4–30.1 | ||
| Performance status (WHO score) | Good <2 | 59.9 | 47.3–75.7 | 49.4 | 43.0–56.9 | 37.0 | 30.4–45.2 | <0.001 |
| Poor ≥2 | 16.3 | 11.5–20.4 | 9.2 | 3.9–21.6 | 6.9 | 2.5–19.2 | ||
| All | 37.5 | 31.7–45.2 | 37.0 | 32.1–42.7 | 27.2 | 22.3–33.2 | – | |
| (b) | ||||||||
| Gender | Female | 78.3 | 60.6–NA | 57.2 | 50.0–65.5 | 47.3 | 39.5–56.7 | 0.706 |
| Male | 64.3 | 51.5–95.7 | 52.9 | 45.9–60.9 | 39.8 | 32.0–49.4 | ||
| Age | ≤40 | NA | 55.2–NA | 63.4 | 49.2–81.8 | 57.6 | 42.0–79.0 | 0.152 |
| >40 | 66.1 | 58.8–93.8 | 54.0 | 48.5–60.0 | 41.6 | 35.6–48.6 | ||
| The period of initiation of imatinib therapy (years) | 2001–2003 | 62.9 | 46.8–107 | 52.1 | 42.9–63.3 | 42.9 | 33.9–54.4 | 0.589 |
| 2004–2006 | 64.9 | 51.5–NA | 53.4 | 45.9–62.1 | 42.5 | 34.7–52.1 | ||
| 2007–2010 | 70.0 | 58.1–NA | 59.6 | 49.7–71.6 | 43.2 | 28.2–66.0 | ||
| Resection of residual disease during imatinib therapy | Yes | NA | NA–NA | 80.3 | 71.8–89.9 | 67.4 | 56.6–80.3 | <0.001 |
| No | 55.2 | 43.9–70 | 46.8 | 41.0–53.4 | 35.6 | 29.3–43.2 | ||
| Primary tumor site | Stomach | 93.4 | 45.1–NA | 53.6 | 45.3–63.4 | 45.8 | 36.2–57.8 | |
| Duodenum | 61.8 | 55.2–NA | 57.1 | 35.9–91.1 | 30.5 | 10.9–84.9 | 0.002 | |
| Small bowel | 70.8 | 60.6–102.4 | 58.2 | 50.6–67.0 | 41.0 | 32.7–51.4 | ||
| Large bowel/rectum | NA | 46.6–NA | 64.9 | 49.1–85.6 | 64.9 | 49.1–85.6 | ||
| Other or intraperitoneally with unknown primary origin | 21.9 | 19.0–62.9 | 29.1 | 16.4–51.7 | 25.5 | 13.6–47.9 | ||
| Presence of liver metastases at imatinib start | Yes | 90.1 | 60.6–NA | 57.0 | 50.1–64.9 | 44.9 | 37.1–54.4 | 0.249 |
| No | 64.9 | 50.2–98.5 | 52.7 | 45.3–61.2 | 42.0 | 34.4–51.4 | ||
| The maximal diameter of the largest tumor (mm) | ≤50 | NA | 98.5–NA | 78.3 | 69.1–88.7 | 63.5 | 51.2–78.8 | <0.001 |
| >50–100 | 124.7 | 96.7–NA | 65.3 | 55.5–76.7 | 61.0 | 50.6–73.6 | ||
| >100 | 46.8 | 37.9–63.7 | 39.6 | 30.4–51.6 | 27.2 | 18.2–40.6 | ||
| Tumor genotype | Wild type | 66.1 | 14.23–NA | 52.9 | 37.4–74.7 | 47.0 | 31.0–71.2 | 0.157 |
| Exon 11 KIT | 82.4 | 60.60–NA | 59.6 | 51.0–69.7 | 47.0 | 37.5–58.9 | ||
| Exon 9 KIT | 78.3 | 55.20–NA | 60.2 | 43.5–83.5 | 42.6 | 25.5–71.1 | ||
| Exon 18 PDGFRA D842V | 15.5 | 8.33–NA | 33.3 | 13.2–84.0 | 33.3 | 13.2–84.0 | ||
| Other | NA | 17.20–NA | 66.7 | 37.9–100.0 | 66.7 | 37.9–100.0 | ||
| Baseline albumin level | Normal | 124.7 | 96.7–NA | 68.7 | 62.5–75.5 | 58.1 | 50.7–66.6 | <0.001 |
| Low | 37.8 | 31.3–50.2 | 25.4 | 15.6–41.3 | 15.2 | 7.6–30.8 | ||
| Baseline neutrophils count | Normal | 124.7 | 95.7–NA | 67.6 | 61.2–74.7 | 56.7 | 49.1–65.4 | <0.001 |
| High | 37.8 | 29.4–49.3 | 31.9 | 21.8–46.6 | 22.8 | 13.8–37.7 | ||
| Baseline hemoglobin level | Normal | 106.4 | 93.4–NA | 65.8 | 59.5–72.7 | 54.1 | 46.8–62.6 | <0.001 |
| Low | 38.8 | 31.7–52.8 | 29.9 | 19.2–46.6 | 24.5 | 14.5–41.3 | ||
| Performance status (WHO score) | Good <2 | 124.7 | 96.7–NA | 70.0 | 64.2–76.5 | 58.4 | 51.3–66.5 | <0.001 |
| Poor ≥2 | 27.5 | 21.9–43.4 | 12.7 | 6.2–26.3 | 8.5 | 3.4–21.3 | ||
| All | 70.8 | 59.9–95.7 | 54.9 | 49.8–60.6 | 43.4 | 37.7–50.0 | – | |
CI confidence interval, NA not applicable