Seigo Takaya

Tumor infiltration pattern into the surrounding tissue has prognostic significance in advanced gastric cancer

Gastric cancer can be classified into three subgroups according to pattern of tumor infiltration into the surrounding tissue: INFa (expanding growth and a distinct border with the surrounding tissue), INFc (infiltrating growth and an indistinct border with the surrounding tissue), and INFb (in-between a and c). How the tumor infiltration pattern (INF) relates to prognosis and type of recurrence in advanced gastric cancer has not been sufficiently explored. We examined 805 consecutive advanced gastric adenocarcinoma patients who underwent curative gastrectomy at our institution between 1980 and 2005. Poor differentiation, serosal invasion, and lymph node metastasis were significantly more frequent in patients with INFc tumors than in those with INFa/b tumors. For patients with a T2 or T3 tumor, there was no significant difference in prognosis between those with INFa/b and with INFc. However, for patients with a T4a or T4b tumor, the prognosis of those with INFc was significantly worse than that of those with INFa/b. In multivariate analysis, INF was an independent prognostic indicator in T4a but not T2, T3, and T4b. Furthermore, the prognosis of T4 patients with INFc tumors was significantly worse than that of those with INFa/b, especially in node-negative but not in node-positive cases. In patients with a T4a or T4b tumor, peritoneal recurrence was significantly more frequent for those with INFc than for those with INFa/b. Our data indicate that INF is useful to predict the prognosis and recurrence pattern in T4a node-negative gastric cancer.

Gastric Adenocarcinoma with Thymic Metastasis after Curative Resection: A Case Report

The peritoneum is the most frequent site of recurrence for gastric cancer after gastrectomy, followed by the liver and lymph nodes. In contrast, metastasis to the thymus is rare. Annual surveillance with computed tomography was performed on a 67-year-old man who previously underwent a distal gastrectomy and D2 lymph node dissection for gastric cancer at Tottori University. Five years after the initial operation, an anterior mediastinal tumor was detected by computed tomography. The patient underwent video-assisted thoracic surgery to remove the tumor. Histopathology revealed adenocarcinoma cells similar to those of the gastric cancer resected 5 years previously. Thymic metastasis was considered likely based on the location of the tumor. The recognition that gastric cancer can metastasize to unusual anatomic locations, such as the thymus, can facilitate an accurate, prompt diagnosis and appropriate treatment.

Combined Pre- and Postoperative Lymphocyte Count Accurately Predicts Outcomes of Patients with Colorectal Cancer

Background: Although preoperative lymphopenia is reportedly a prognostic factor in cancer patients, the association between postoperative lymphopenia and patient prognosis has not been widely studied. Methods: We enrolled 379 patients who underwent surgery for colorectal cancer (CRC) to analyze correlations among pre- and postoperative lymphocyte counts (LCs) and prognosis in patients with CRC. Results: Pre- and postoperative LCs were significantly correlated (r = 0.615, p < 0.0001). Based on results of receiver operating characteristic analysis, patients were subgrouped as preoperative LC ≥1,280 (pre-LCHigh, n = 234), preoperative LC < 1,280 (pre-LCLow, n = 145); and as postoperative LC ≥680 (post-LCHigh, n = 246), and postoperative LC < 680 (post-LCLow, n = 133). Five-year disease-specific survival rates significantly differed between pre-LCHigh (88.6%) and pre-LCLow (72.5%) groups (p < 0.0001); and also between the post-LCHigh (88.5%) and post-LCLow (71.1%) groups (p < 0.0001). Five-year disease-specific survival rates of patients who were both pre-LCLow and post-LCLow was significantly lower than those for patients who were either pre-LCHigh or post-LCHigh or pre-LCHigh/post-LCHigh (p = 0.0003). Multivariate analysis indicated that the combination of pre- and postoperative LC was an independent prognostic indicator. Conclusions: The combination of pre- and postoperative LC is a predictive factor for prognosis in CRC patients.