What is the role of para-aortic lymphadenectomy (removal of lymph nodes near the aorta) in the management of stomach cancer (ca stomach)?

Role of Para-Aortic Lymphadenectomy in Gastric Cancer

Preventive para-aortic lymph node dissection (PAND) is not recommended as a standard procedure for resectable advanced gastric cancer as it does not improve long-term survival compared to standard D2 lymphadenectomy alone. 1

Current Guidelines on Para-Aortic Lymphadenectomy

Para-aortic lymph node dissection in gastric cancer remains controversial across major guidelines:

• Chinese Society of Clinical Oncology (CSCO): Although preventive PAND cannot improve long-term survival in resectable advanced gastric cancer, therapeutic PAND remains controversial. Suitable patients should be enrolled in clinical trials. 1

• Japanese Gastric Cancer Association: The benefit of prophylactic PAND was denied by the Japanese randomized controlled trial JCOG 9501. Although R0 resection may be possible for tumors with para-aortic nodal involvement without other non-curative factors, the prognosis remains poor. 1

• Italian Research Group for Gastric Cancer (GIRCG): D2 plus procedures, including removal of paraaortic nodes (16a2, 16b1), may be justified only in patients at high risk of metastases at these stations (advanced tumors of the upper third, advanced tumors and diffuse histotype located in the distal two-thirds of the stomach). However, these procedures should be performed only in centers specialized with D2 lymphadenectomy or in clinical trials. 1

Evidence Against Routine PAND

Meta-analyses have demonstrated that D2 plus PAND:

• Does not improve 5-year overall survival rates compared to standard D2 lymphadenectomy 2
• Significantly increases operation time and blood loss 2
• Can be performed as safely as standard D2 resection without increasing post-operative mortality, but fails to benefit overall survival in patients with advanced gastric cancer 2

Specific Scenarios Where PAND May Be Considered

Despite the general recommendation against routine PAND, there are specific scenarios where it might be considered:

1. Clinically detected para-aortic nodal metastases: Preoperative chemotherapy followed by PAND may be indicated in these cases 3

2. Advanced carcinoma of the upper-third of the stomach: Some evidence suggests that left-paraaortic lymphadenectomy may benefit such patients if the overall number of infiltrated nodes is low (≤10) 4

3. Neoadjuvant chemotherapy followed by D2+PAND: This approach has shown promising results in patients radiologically diagnosed with PAN metastases, with 57% of patients surviving for 5 years after two cycles of neoadjuvant S-1/CDDP followed by surgery 5

Practical Approach to Para-Aortic Lymphadenectomy

When considering PAND in gastric cancer:

• Standard approach: Perform standard D2 lymphadenectomy for potentially curable T2-T4 tumors
• Avoid routine PAND: Do not perform prophylactic PAND as a standard procedure
• Consider PAND in select cases:
  • Patients with clinically detected PAN metastases who have responded to neoadjuvant chemotherapy
  • Advanced tumors of the upper third of the stomach with limited nodal disease
  • As part of clinical trials

Cautions and Pitfalls

• PAND should only be performed by experienced surgeons in specialized centers 3
• The procedure significantly increases operation time and blood loss compared to standard D2 lymphadenectomy 2
• The potential benefit must be weighed against the increased surgical complexity
• Para-aortic nodal involvement is classified as M1 (distant metastasis) in current staging systems, making it stage IV disease 5

In conclusion, while standard D2 lymphadenectomy remains the cornerstone of surgical treatment for potentially curable gastric cancer, PAND should be reserved for specific clinical scenarios and performed in specialized centers, preferably within clinical trials.