[Ultra-Short-Term Neoadjuvant Imatinib Leads to Curative Resection and Pathological Complete Response in a Large...

Area of Science:

• Gastroenterology
• Oncology
• Surgical Oncology

Background:

• Surgical resection is standard for primary gastrointestinal stromal tumors (GISTs).
• Neoadjuvant imatinib is recommended for large (>10 cm) or high-risk GISTs.
• Complete resection is crucial for optimal outcomes in GIST management.

Purpose of the Study:

• To report a rare case of successful curative resection of an unresectable gastric GIST.
• To evaluate the efficacy of ultra-short-term neoadjuvant imatinib therapy.
• To highlight the potential for achieving pathological complete response (pCR) with brief imatinib treatment.

Main Methods:

• A 62-year-old male with a >15 cm invasive gastric GIST received 12 days of neoadjuvant imatinib (400 mg/day).
• Tumor response was assessed via CT scans.
• Curative surgical resection was performed after imatinib treatment.
• Pathological examination confirmed the response.

Main Results:

• Neoadjuvant imatinib led to significant tumor necrosis and shrinkage within 7 days.
• Despite complications (pleural effusion, pneumonia) leading to treatment discontinuation on day 12, curative surgery was successful.
• Pathological examination revealed a complete disappearance of GIST cells, achieving pCR.
• The patient remained recurrence-free post-operatively.

Conclusions:

• Ultra-short-term neoadjuvant imatinib therapy can induce pCR in advanced gastric GISTs, enabling curative resection.
• This approach offers a potential alternative for managing initially unresectable GISTs.
• Further molecular analyses are warranted to understand the mechanisms behind this response.