Radiotherapy’s role after D2 lymph node dissection with or without omentectomy in gastric cancer treatment remains a critical but nuanced question in oncology, balancing potential survival benefits against risks of toxicity. While D2 lymphadenectomy is a standard surgical approach for locally advanced gastric cancer, the addition of postoperative radiotherapy is considered primarily to improve local control and potentially survival, especially when surgical margins are close or nodal disease is extensive.
Short answer: Radiotherapy after D2 lymph node dissection with or without omentectomy in gastric cancer is used as an adjuvant treatment to reduce locoregional recurrence and improve survival in select patients, particularly those with high-risk features, although its routine use remains debated depending on surgical quality and tumor stage.
Understanding the role of radiotherapy in this setting requires exploring gastric cancer epidemiology, surgical standards, radiotherapy’s therapeutic rationale, and clinical evidence guiding its application.
Gastric Cancer and Surgical Management
Gastric adenocarcinoma accounts for 90% to 95% of gastric malignancies, with prognosis largely dependent on disease stage and nodal involvement. According to the National Cancer Institute (cancer.gov), early-stage gastric cancer confined to the stomach wall has a 5-year survival rate approaching 50%, but most patients present with advanced disease, reducing survival significantly. Surgical resection with adequate lymphadenectomy remains the cornerstone of curative treatment.
D2 lymph node dissection involves removal of perigastric and regional lymph nodes and is considered a standard approach in many countries, including Japan and South Korea, where gastric cancer incidence is high. The omentectomy, removal of the omentum, is often performed concurrently to remove potential sites of microscopic spread.
While surgery can be curative, locoregional recurrence remains a major cause of treatment failure. The extent of lymph node dissection impacts recurrence risk; D2 dissection is more extensive than D1 and associated with improved staging and control but can be technically demanding.
Rationale for Radiotherapy After Surgery
Postoperative radiotherapy aims to eradicate residual microscopic disease in the tumor bed and regional lymph nodes that surgery may not have completely cleared. This is particularly relevant in patients with positive lymph nodes, close or positive margins, or advanced T stage tumors.
Radiotherapy can reduce locoregional relapse, which is significant because recurrence in the gastric bed or regional nodes is common and often leads to poor outcomes. By improving local control, radiotherapy may translate into survival benefits, especially when combined with chemotherapy.
The Interplay of Radiotherapy and Surgery Extent
The necessity and benefit of adjuvant radiotherapy depend on the quality of surgery performed. In centers where D2 dissection is standard and well-performed, the incremental benefit of radiotherapy is less clear because the surgery itself achieves substantial locoregional control. Conversely, in settings where less extensive lymphadenectomy is performed, or where residual nodal disease remains, radiotherapy plays a more prominent role.
Clinical trials such as the INT-0116 trial demonstrated improved survival with postoperative chemoradiotherapy compared to surgery alone, but most patients in that study underwent less extensive lymphadenectomy (D0 or D1). Therefore, extrapolating these results to patients who have had a D2 dissection is complex.
Current Evidence and Guidelines
Recent studies and meta-analyses show mixed results about the benefit of radiotherapy after D2 dissection. Some evidence suggests that in patients with node-positive gastric cancer, postoperative chemoradiotherapy improves disease-free survival and reduces locoregional recurrence compared to chemotherapy alone.
For example, the ARTIST trial conducted in Korea compared adjuvant chemotherapy with or without radiotherapy after D2 dissection. The initial results showed no significant difference in disease-free survival overall, but subgroup analyses indicated benefits in patients with nodal involvement. This highlights that radiotherapy’s role may be most valuable in high-risk patients.
Moreover, radiotherapy techniques have advanced, allowing more precise targeting that reduces toxicity to surrounding organs like the liver, kidneys, and intestines, making adjuvant radiotherapy safer and more feasible.
Omentectomy’s Role and Radiotherapy
The omentum can harbor microscopic tumor deposits and is often removed during gastrectomy. Whether omentectomy influences the need or efficacy of radiotherapy is less well-defined. The omentum’s removal may reduce peritoneal recurrence risk, but radiotherapy’s main target remains the gastric bed and regional lymph nodes.
Therefore, omentectomy is generally considered part of comprehensive surgical management, while radiotherapy addresses residual nodal and local disease risk.
Considerations in Older Adults and Frailty
Treatment decisions for gastric cancer, including the use of radiotherapy, are influenced by patient factors such as age and frailty. As noted in studies of older adults (from sources like ncbi.nlm.nih.gov on frailty prevalence), frailty increases vulnerability to treatment-related toxicity and complications.
Thus, in frail or older patients, the risks of radiotherapy must be carefully weighed against potential benefits. Multidisciplinary assessment is critical to tailor therapy, especially when considering aggressive multimodal treatments.
Geographical and Practice Variations
The use of adjuvant radiotherapy after D2 dissection varies globally. In East Asia, where D2 lymphadenectomy is standard and gastric cancer incidence is high, adjuvant chemotherapy alone is often preferred, reserving radiotherapy for selected cases.
In Western countries, where D2 dissection is less commonly performed or less extensive, postoperative chemoradiotherapy has been more widely adopted based on clinical trial data.
This variation reflects differences in surgical expertise, patient populations, and healthcare infrastructure, emphasizing the importance of individualized treatment approaches.
Toxicity and Quality of Life
Radiotherapy, especially when combined with chemotherapy, can cause acute and late toxicities, including gastrointestinal symptoms, hematologic effects, and damage to nearby organs. Advances in radiation planning and delivery aim to minimize these effects.
Balancing local control benefits with potential quality-of-life impacts is a key consideration, particularly in older or frail patients.
Takeaway
Radiotherapy after D2 lymph node dissection with or without omentectomy in gastric cancer plays a nuanced role, chiefly to improve locoregional control and survival in patients with advanced disease or nodal involvement. While D2 surgery reduces recurrence risk, radiotherapy can provide additional benefit in selected high-risk cases. Treatment decisions must consider surgical quality, tumor stage, patient frailty, and regional practices. Ongoing research and refined radiotherapy techniques continue to shape its optimal use in multidisciplinary gastric cancer care.
For further reading and evidence, sources such as the National Cancer Institute’s PDQ summary on gastric cancer treatment (cancer.gov), clinical trial reports like the ARTIST trial, and expert guidelines from oncology societies provide detailed insights into this complex treatment landscape.
Potential sources for deeper exploration include:
- National Cancer Institute (cancer.gov) PDQ on Gastric Cancer Treatment - American Society of Clinical Oncology (asco.org) guidelines (noting some pages may be temporarily unavailable) - Clinical trial publications on adjuvant radiotherapy after D2 dissection - Regional gastric cancer treatment guidelines from Japan and Korea - Research articles on frailty and treatment tolerance in older adults (ncbi.nlm.nih.gov) - Meta-analyses and systematic reviews on postoperative radiotherapy efficacy and toxicity - Reviews on surgical techniques and lymphadenectomy extent in gastric cancer management
