Distribution of Nodal Metastases by T-Stage in Gastric Cancer: Systematic Review

Overview

This systematic review evaluates the prevalence of lymph node metastases across individual lymph node stations in gastric cancer, stratified by T-stage. It highlights the variation in nodal involvement between early (T1) and advanced (T2-T4) tumors, informing the extent of lymphadenectomy required.

Background

Gastric cancer remains a leading cause of cancer mortality worldwide despite decreasing incidence. Lymph node involvement is a critical prognostic factor influencing recurrence and survival. Surgical treatment includes lymphadenectomy with varying extents (D1, D2) based on tumor stage and location. Accurate lymph node dissection is essential to reduce loco-regional recurrence but must be balanced against morbidity and mortality risks.

Data Highlights

The overall prevalence of lymph node metastases in T1 gastric tumors ranges from 8% to 31%, whereas in T2-T4 tumors, it increases substantially to 45%–90%. D1 lymphadenectomy involves resection of peri-gastric lymph nodes (stations 1–6 and 7), while D2 lymphadenectomy extends to additional stations (8a, 9, 11p, 11d, 12a). Morbidity and mortality rates are higher with D2 compared to D1 dissections (morbidity: 43%-46% vs. 25%-28%; mortality: 10%-13% vs. 4%-6.5%).

Key Findings

• Prevalence of nodal metastases increases markedly with advancing T-stage, from 8%-31% in T1 to 45%-90% in T2-T4 gastric cancers.
• Different lymph node stations show variable rates of metastases depending on the T-stage, supporting tailored lymphadenectomy approaches.
• D1 lymphadenectomy is recommended for T1a tumors and select well-differentiated T1b tumors not meeting endoscopic resection criteria.
• D2 lymphadenectomy, while more extensive, is associated with improved loco-regional control but higher morbidity and mortality.
• Endoscopic resection criteria for early gastric cancer are based on tumor size, differentiation, ulceration, and depth, reflecting negligible lymph node metastasis risk in selected cases.
• Accurate staging and classification systems (JGCA and AJCC 7th edition) are critical for guiding surgical management and lymphadenectomy extent.

Clinical Implications

Clinicians should consider T-stage when planning the extent of lymphadenectomy in gastric cancer surgery to balance oncologic benefit with surgical risk. Early-stage tumors (T1) may be adequately treated with limited lymph node dissection or endoscopic resection when criteria are met, while advanced tumors require more extensive lymphadenectomy. Understanding nodal metastasis distribution aids in optimizing surgical strategies and improving patient outcomes.

Conclusion

The prevalence and distribution of nodal metastases in gastric cancer vary significantly by T-stage, underscoring the need for stage-adapted lymphadenectomy. Tailored surgical approaches can potentially improve survival while minimizing morbidity.

References

1. Japanese Gastric Cancer Association -- Gastric Cancer Treatment Guidelines
2. AJCC Cancer Staging Manual, 7th Edition -- Gastric Cancer Staging
3. Critical Appraisal Skills Program (2017) -- CASP Checklist