Survival Outcomes and Patterns of Failure in Patients with Carcinoma Stomach Who Underwent D2 Lymphadenectomy Followed by Either Adjuvant Chemoradiation or Chemotherapy Alone: A Retrospective Review from a Tertiary Care Cancer Research Institute

Abstract

<h3>Purpose/Objective(s)</h3> Surgery remains the mainstay of curative treatment for gastric cancer. However, there is varied practice across the globe regarding adjuvant treatment. This single institute retrospective study analyzed all gastric cancer patients who underwent curative surgery with D2 lymph nodal dissection, followed by either adjuvant chemotherapy (CT) alone or concurrent chemoradiation (CRT). <h3>Materials/Methods</h3> The study period was from January 2010 to December 2017. The patient data was gathered from electronic files and analyzed using Statistical Package for the Social Sciences, version 23. A comparison was made between the two adjuvant arms in terms of clinical outcomes, including overall survival (OS), recurrence-free survival (RFS), and failure patterns. <h3>Results</h3> 247 eligible patients who met the criteria were considered for analysis. There was a male preponderance, with 65.99% (163) males and 34.01% (84) females. The median age at diagnosis was 58 (18 to 87 years). The distal stomach was the most common location of tumors, with 64.3% occurring in the antro-pyloric region. Histopathological examination revealed stage-III cancer in the majority of the patients {44.53% (110)}, followed by stage-II {29.14% (72)}, and stage-I {12.96% (32)}. Adjuvant CRT was received by 49.39% (122) patients, and perioperative or adjuvant CT alone by 50.61% (125) patients. 19.02% (47) developed disease recurrence following treatment. Amongst these 47 patients, 61.70 % (29/47) had a locoregional, and 38.30% (18/47) failed distally. Lymph nodes were the most common sites of local failure accounting for 48.93% (23/47) of all cases, and the liver was the most common site of isolated distal failure 10% (5/47), followed by lung and bone (8%) each. Local recurrence was lower in the CRT group {34.49% (10/29) in the CRT arm and 65.51% (19/29) in CT alone arm, p-value – 0.087}. While distant metastasis was lower in CT alone arm {38.89% (7/18) vs. 61.11% (11/18), p-value – 0.302}. Of the entire study, the 5-year OS and RFS were 66.7% and 64.3%, respectively. The OS was 63.2% in the CRT arm and 67.8% in CT alone arm (p-value – 0.607). The RFS was 61.9% in the CRT arm and 65.6% in CT alone arm (0.138) <h3>Conclusion</h3> In our analysis, patients on the CRT arm had lower local recurrence; however, patients on the CT alone arm had lower distant metastasis. The CT alone arm showed a trend towards improved survival compared to the CRT arm; nevertheless, the difference was statistically non-significant. This warrants further studies to effectively combine radiation and chemotherapy in the adjuvant setting to lower both locoregional and distal metastasis.