Arithmetic topology in Ihara theory

Ihara initiated to study a certain Galois representation which may be seen as an arithmetic analogue of the Artin representation of a pure braid group. We pursue the analogies in Ihara theory further, following after some issues and their inter-relations in the theory of braids and links such as Milnor invariants, Johnson homomorphisms, Magnus-Gassner cocycles and Alexander invariants, and study relations with arithmetic in Ihara theory.Comment: 66pages, to appear in Publ. Res. Inst. Math. Sci., corrected typo

Clinical analysis of small-sized peripheral lung cancer

AbstractObjective: In Japan, with the initiation of the lung cancer screening program, small-sized peripheral lung cancer in which the diameter is 2 cm or less has been increasing. The purpose of this study is to determine the clinicopathologic behavior of small-sized lung cancer. Methods: Four hundred ninety-six patients with cT1 N0, peripheral, resected non-small-cell lung cancer, who were operated on between 1980 and 1996, were selected, grouped by tumor diameter or histologic type, and then analyzed for clinicopathologic behavior. On the basis of measured diameter roentgenographically, the patients were divided into two groups; group c-S with lesions 2 cm or less in diameter and group c-L with lesions 2.1 to 3 cm in diameter. Results: Lymph node metastasis was recognized in 18% of group c-S, in 23% of group c-L, and in 21% for the entire clinical group. The rate of those with the progressive state was 19% in group c-S and 26% in group c-L. The 5-year survival was 79.5% in group c-S and 69.3% in group c-L (i.e., there was a significant difference between the two groups). Conclusion: Compared with the patients with lesions 2.1 to 3 cm in diameter, the patients with small-sized lung cancer had a milder progressive state and a better prognosis.(J Thorac Cardiovasc Surg 1998;115:1015-20

Pulmonary resection for metachronous metastatic gastric cancer diagnosed using multi-detector computed tomography: Report of five cases

Introduction As pulmonary resection for metastatic gastric cancer has been rarely reported on, the role of metastasectomy remains unclear in such settings. We reviewed the clinicopathological characteristics and surgical outcomes of patients with metachronous pulmonary metastasis from gastric cancer (MPMGC) diagnosed using multi-detector computed tomography (MDCT) who underwent pulmonary resection. Presentation of case From September 2002 to May 2018, five patients underwent pulmonary resection for MPMGC at Shizuoka Cancer Center. All patients received curative resection for initial gastric cancer. Three patients received adjuvant chemotherapy. The median age at pulmonary resection was 70 years. The median disease-free interval between initial gastrectomy and MPMGC diagnosis was 41 months. The first site of recurrence was the lung in all patients. All patients were diagnosed as having primary lung cancer using MDCT before pulmonary resection and fit the surgical indication for primary lung cancer. Lobectomy was performed in three patients, while wedge resection was performed in two. The median overall survival following pulmonary resection was 79 (range, 18–89) months. Two patients experienced recurrence. While one showed recurrence in the mediastinal lymph node, in the other it was observed in the remnant lung; the latter underwent repeated pulmonary resection followed by systemic chemotherapy. Four patients survived for longer than 4 years after pulmonary resection. Conclusions Of the five patients with MPMGC diagnosed using MDCT who underwent pulmonary resection, long-term survival was achieved after pulmonary resection in four. Thus, pulmonary resection may be considered for those diagnosed with lung nodules after surgery for gastric cancer, and who fit the surgical indication for primary lung cancer

Pulmonary function after segmentectomy for small peripheral carcinoma of the lung

AbstractObjective: The aim of this study is to compare the pulmonary function after a segmentectomy with that after a lobectomy for small peripheral carcinoma of the lung. Patients And Methods: Between 1993 and 1996, segmentectomy and lobectomy were performed on 48 and 133 good-risk patients, respectively. Lymph node metastases were detected after the operation in 6 and 24 patients of the segmentectomy and lobectomy groups, respectively. For bias reduction in comparison with a nonrandomized control group, we paired 40 segmentectomy patients with 40 lobectomy patients using nearest available matching method on the estimated propensity score. Results: Twelve months after the operation, the segmentectomy and lobectomy groups had forced vital capacities of 2.67 ± 0.73 L (mean ± standard deviation) and 2.57 ± 0.59 L, which were calculated to be 94.9% ± 10.6% and 91.0% ± 13.2% of the preoperative values (P = .14), respectively. The segmentectomy and lobectomy groups had postoperative 1-second forced expiratory volumes of 1.99 ± 0.63 L and 1.95 ± 0.49 L, which were calculated to be 93.3% ± 10.3% and 87.3% ± 14.0% of the preoperative values, respectively (P = .03). The multiple linear regression analysis showed that the alternative of segmentectomy or lobectomy was not a determinant for postoperative forced vital capacity but did affect postoperative 1-second forced expiratory volume. Conclusion: Pulmonary function after a segmentectomy for a good-risk patient is slightly better than that after a lobectomy. However, segmentectomy should be still the surgical procedure for only poor-risk patients because of the difficulty in excluding patients with metastatic lymph nodes from the candidates for the procedure. (J Thorac Cardiovasc Surg 1999;118:536-41