What is the adjuvant treatment for stomach leiomyosarcoma?

Adjuvant Treatment for Gastric Leiomyosarcoma

For high-risk gastric leiomyosarcoma, doxorubicin-based chemotherapy is the recommended adjuvant treatment following complete surgical resection, with high-risk defined as tumors that are high-grade, deep, or >5 cm. 1

Surgical Management

• Complete surgical resection with negative margins is the primary treatment for localized gastric leiomyosarcoma 2
• Wedge resection or partial gastric resection is acceptable as long as negative margins can be achieved 3
• Lymphadenectomy is not routinely required as nodal involvement is uncommon in leiomyosarcoma 4

Risk Assessment for Adjuvant Therapy

• Decision for adjuvant therapy should be based on risk factors including:
  • Tumor grade (high-grade tumors benefit most) 1
  • Tumor size (>5 cm considered high-risk) 1
  • Depth of invasion 1
  • Margin status 1

Adjuvant Chemotherapy Options

• Doxorubicin-based regimens are the standard first-line treatment for high-risk patients 1
• Options include:
  • Single-agent doxorubicin 1
  • Doxorubicin plus dacarbazine (preferred over ifosfamide-containing regimens for leiomyosarcoma) 1
  • Doxorubicin plus ifosfamide may be considered when higher response rates are desired in patients with good performance status, though ifosfamide has shown less convincing activity in leiomyosarcoma 1

Radiation Therapy

• Postoperative radiation therapy has limited value in leiomyosarcoma and is associated with significant toxicities 2
• Radiation therapy did not improve survival or relapse-free survival in a randomized trial of leiomyosarcoma 2
• May be considered only in selected cases with well-defined areas at high risk for local recurrence 2

Second-line Treatment Options

• Trabectedin has proven effective in leiomyosarcoma after failure of anthracycline-based therapy 1
• Gemcitabine with or without docetaxel has shown activity in leiomyosarcoma 1
• Dacarbazine has demonstrated activity as second-line therapy 1
• Gemcitabine plus dacarbazine has shown improved overall survival and progression-free survival over dacarbazine alone 1

Special Considerations

• Approximately 50% of leiomyosarcomas may express estrogen and/or progesterone receptors 5
• Hormone replacement therapy containing estrogens is contraindicated in patients with leiomyosarcoma 5
• Unopposed estrogen may increase the risk of tumor growth in hormone receptor-positive leiomyosarcomas 5

Follow-up Recommendations

• High-grade patients should be followed every 3-4 months in the first 2-3 years 2
• Then twice a year up to the fifth year, and once a year thereafter 2
• Follow-up should include appropriate imaging to detect recurrence 6
• MRI is preferred for local recurrence detection, while CT is used for lung metastases surveillance 6

Pitfalls and Caveats

• The value of adjuvant chemotherapy remains controversial with conflicting study results 1
• Local recurrence rates can be high (up to 38%) even after curative resection 3
• The dominant mode of recurrence is liver and peritoneal metastasis rather than lymph node recurrence 4
• Treatment decisions should be made in centers with expertise in sarcoma management 1