Table 1.
Demographic and Disease Characteristics and Prior Treatment
| Characteristic | Overall |
Amplified KIT (n = 11) |
Mutated KIT (n = 13) |
P | |||
|---|---|---|---|---|---|---|---|
| No. | % | No. | % | No. | % | ||
| Institution | .34 | ||||||
| Dana-Farber Cancer Institute | 7 | 29.2 | 5 | 45.5 | 2 | 15.4 | |
| Massachusetts General Hospital | 2 | 8.3 | — | — | 2 | 15.4 | |
| Moffitt Cancer Center | 5 | 20.8 | 2 | 18.2 | 3 | 23.1 | |
| University of Chicago | 3 | 12.5 | 1 | 9.1 | 2 | 15.4 | |
| The Angeles Clinic | 2 | 8.3 | 2 | 18.2 | — | — | |
| University of Colorado | 4 | 16.7 | 1 | 9.1 | 3 | 23.1 | |
| MD Anderson Cancer Center | 1 | 4.2 | — | — | 1 | 7.7 | |
| Age, years | .4 | ||||||
| Median | 65 | 69 | 64 | ||||
| Range | 42-84 | 55-84 | 42-80 | ||||
| Sex | .36 | ||||||
| Female | 18 | 75 | 7 | 63.6 | 11 | 84.6 | |
| Male | 6 | 25 | 4 | 36.4 | 2 | 15.4 | |
| Race | .44 | ||||||
| Unknown | 1 | 4.2 | — | — | 1 | 7.7 | |
| White | 19 | 79.2 | 8 | 72.7 | 11 | 84.6 | |
| African American | 1 | 4.2 | 1 | 9.1 | — | — | |
| Asian | 1 | 4.2 | 1 | 9.1 | — | — | |
| Multiracial | 1 | 4.2 | 1 | 9.1 | — | — | |
| Other | 1 | 4.2 | — | — | 1 | 7.7 | |
| Ethnicity | .22 | ||||||
| Hispanic or Latino | 3 | 12.5 | — | — | 3 | 23.1 | |
| Non-Hispanic | 21 | 87.5 | 11 | 100 | 10 | 76.9 | |
| Disease stage | .53 | ||||||
| M1a | 1 | 4.2 | 1 | 9.1 | — | — | |
| M1b | 8 | 33.3 | 4 | 36.4 | 4 | 30.8 | |
| M1c | 15 | 62.5 | 6 | 54.5 | 9 | 69.2 | |
| Melanoma subtype | .24 | ||||||
| Mucosal | 17 | 70.8 | 6 | 54.5 | 11 | 84.6 | |
| Acral | 6 | 25 | 4 | 36.4 | 2 | 15.4 | |
| CSD | 1 | 4.2 | 1 | 9.1 | — | — | |
| ECOG performance status | .99 | ||||||
| 0 | 17 | 70.8 | 8 | 72.7 | 9 | 69.2 | |
| 1 | 7 | 29.2 | 3 | 27.3 | 4 | 30.8 | |
| Site for KIT molecular testing | .99 | ||||||
| Primary | 12 | 50 | 5 | 45.5 | 7 | 53.8 | |
| Metastatic | 12 | 50 | 6 | 54.5 | 6 | 46.2 | |
| Prior radiation | .24 | ||||||
| No | 10 | 41.7 | 3 | 27.3 | 7 | 53.8 | |
| Yes | 14 | 58.3 | 8 | 72.7 | 6 | 46.2 | |
| Prior chemotherapy | .44 | ||||||
| No | 11 | 45.8 | 4 | 36.4 | 7 | 53.8 | |
| Yes | 13 | 54.2 | 7 | 63.6 | 6 | 46.2 | |
| Prior therapies | |||||||
| Median | 1 | 1 | 1 | — | |||
| Range | 1-2 | 1-2 | 1-2 | ||||
NOTE. Percentages are calculated down the columns (within type of mutation). Acral melanoma: six (11.8%; 90% CI, 5% to 22%) of 51 KIT mutations; mucosal melanoma: 15 (14.6%; 90% CI, 9% to 22%) of 103 KIT mutations; chronically sun-damaged (CSD) melanoma: two (3.9%; 90% CI, 1% to 12%) of 51 KIT mutations. P values compare amplified versus mutated KIT.
Abbreviation: ECOG, Eastern Cooperative Oncology Group.