Chemoradiotherapy or chemotherapy as adjuvant treatment for resected gastric cancer: should we use selection criteria?

Abstract

The management of gastric adenocarcinoma is essentially based on surgery followed by adjuvant treatment. Adjuvant chemotherapy (CT) as well as chemoradiotherapy (CTRT) have proven their effectiveness in survival outcomes compared to surgery alone. However, there is little data comparing the two adjuvant approaches. This study aimed to compare the prognosis and survival outcomes of patients with gastric adenocarcinoma operated and treated by adjuvant radio-chemotherapy or chemotherapy. We retrospectively evaluated 80 patients with locally advanced gastric cancer (LGC) who received adjuvant treatment. We compared survival outcomes and patterns of recurrence of 53 patients treated by CTRT and those of 27 patients treated by CT. After a median follow-up of 38.48 months, CTRT resulted in a significant improvement of the 5-year PFS (60.9% vs. 36%, p = 0.03) and the 5-year OS (55.9% vs. 33%, p = 0.015) compared to adjuvant CT. The 5-year OS was significantly increased by adjuvant CTRT (p = 0.046) in patients with lymph node metastasis, and particularly those with advanced pN stage (p = 0.0078) and high lymph node ratio (LNR) exceeding 25% (p = 0.012). Also, there was a significant improvement of the PFS of patients classified pN2-N3 (p = 0.022) with a high LNR (p = 0.018). CTRT was also associated with improved OS and PFS in patients with lymphovascular and perineural invasion (LVI and PNI) compared to chemotherapy. There is a particular survival benefit of adding radiotherapy to chemotherapy in patients with selected criteria such as lymph node involvement, high LNR LVI, and PNI.