Table 1.
Characteristics of the 5 Patients With TRK Fusion Sarcomas Treated With Larotrectinib Followed by Surgical Resection
| Baseline Characteristics | Value |
|---|---|
| Median age at time of initial diagnosis (range) | 9 mo (1 mo‐12 y) |
| Male:female ratio | 3:2 |
| Diagnosis, no. | |
| Infantile fibrosarcoma | 3 |
| Other sarcoma | 2 |
| Extent of disease at initial diagnosis, no. | |
| Locally advanced | 5 |
| Metastatic | 0 |
| Primary tumor site, no. | |
| Lower extremity | 2 |
| Upper extremity/shoulder | 2 |
| Pelvis | 1 |
| TRK fusion | |
| ETV6‐NTRK3 | 2 |
| TPM3‐NTRK1 | 1 |
| PDE4DIP‐NTRK1 | 1 |
| SQSTM1‐NTRK1 | 1 |
| Characteristics at Initiation of Larotrectinib | |
| Median age at enrollment (range) | 2 y (0.4‐12 y) |
| Extent of disease at time of study enrollment, no. | |
| Locally advanced | 5 |
| Metastatic | 0 |
| No. of prior systemic therapies, no. | |
| 0 | 1 |
| 1 | 1 |
| ≥2 | 3 |
| No. of prior surgical resections, no. | |
| 0 | 3 |
| 1 | 1 |
| 2 | 1 |
| Median age at time of first surgical resection prior to larotrectinib (range)a | 15.5 mo (2‐29 mo) |
| Characteristics of First Surgical Resection After Initiating Larotrectinib | |
| Median age at time of first surgical resection after initiating larotrectinib (range) | 35 mo (11‐163 mo) |
| Median no. of neoadjuvant cycles (range) | 6 (4‐9) |
| Median d from last larotrectinib to surgery | 1 (0‐1) |
| Extent of surgical resection, no. | |
| R0 | 3 |
| R1 | 1 |
| R2 | 1 |
| Pathologic response, no. | |
| Complete or near‐complete | 3 |
| Viable tumor seen | 2 |
Abbreviations: ETV6, ETS variant 6; NTRK1, neurotrophic receptor tyrosine kinase 1; NTRK3, neurotrophic receptor tyrosine kinase 3; PDE4DIP, phosphodiesterase 4D‐interacting protein; R0, negative resection margins with no tumor at the inked resection margin; R1, microscopic residual tumor at the resection margin; R2, macroscopic residual tumor at the resection margin; SQSTM1, sequestosome 1; TPM3, tropomyosin 3; TRK, tropomyosin receptor kinase.
a
Three patients did not undergo surgical resection prior to initiating treatment with larotrectinib.