Katsuyoshi Hatakeyama

BACKGROUND: Extended radical esophagectomy with three-field lymphadenectomy for patients with thoracic esophageal cancer has been shown to be effective. But even if this operation is performed, some patients still experience relapse of the disease. The purpose of this study was to clarify the pattern and timing of recurrence after extended radical esophagectomy. STUDY DESIGN: Recurrence of esophageal squamous cell carcinoma was examined in 171 of 174 patients who underwent extended radical esophagectomy with three-field lymphadenectomy. Recurrence patterns were classified as locoregional (at the site of the primary tumor, the anastomotic site, or the lymph nodes), hematogenous, and other (pleura or site of gastrostomy). Factors associated with recurrence were identified using univariate and multivariate statistical methods for survival analysis. RESULTS: The overall 5-year survival rate was 55.6%. Recurrence was recognized in 74 patients (43.3%). The median disease-free interval until recurrence was 11 months. Thirty patients (17.5%) developed a locoregional recurrence, and 24 (14.0%) developed a hematogenous recurrence. Five patients (2.9%) developed both recurrences simultaneously and were classified as hematogenous recurrences. Of 30 patients with cervical lymph node metastasis, recurrent disease was recognized in 19 patients (63.3%). In multivariate analysis of 160 patients, the depth of invasion and pM-lym (cervical or celiac lymph node metastasis) were significant factors for locoregional recurrence; the depth of invasion and number of lymph node metastases at operation were significant factors for hematogenous recurrence. Survival time for patients with hematogenous recurrence (median 16 months) was significantly shorter than that of patients with locoregional recurrence (median 25.5 months). CONCLUSIONS: Locoregional recurrence is associated mainly with the extent of the local tumor and lymph node metastasis; hematogenous recurrence is not only associated with tumor stage but also with the tumor's oncologic behavior.

BACKGROUND: The current study was performed to clarify whether the presence of residual carcinoma in situ at ductal resection margins differs prognostically from residual invasive ductal lesions in patients undergoing surgical resection for extrahepatic cholangiocarcinoma. METHODS: A retrospective analysis of 84 patients with extrahepatic cholangiocarcinoma who underwent surgical resection was conducted. The ductal resection margin status was classified as negative (n = 64 patients), positive with carcinoma in situ (n = 11 patients), or positive with invasive carcinoma (n = 9 patients). The median follow-up period was 105 months. RESULTS: Ductal margin status was found to be a strong independent prognostic factor by both univariate (P = 0.0002) and multivariate (P = 0.0039) analyses. The outcome after surgical resection was comparable between patients with negative ductal margins (median survival time of 45 months; cumulative 10-year survival rate of 40%) and those with positive ductal margins with carcinoma in situ (median survival time of 99 months; cumulative 10-year survival rate of 23%; P = 0.4742). In patients with positive ductal margins, the outcome was found to be significantly better in patients with residual carcinoma in situ than in those with residual invasive carcinoma (median survival time of 21 months; cumulative 5-year survival rate of 0%; P = 0.0003). Of 11 patients with residual carcinoma in situ, 4 died of tumor recurrence and the initial site of the disease recurrence was local. All 9 patients with residual invasive carcinoma died of disease recurrence (local recurrence with or without distant metastases) within 40 months after surgical resection. CONCLUSIONS: After surgical resection for extrahepatic cholangiocarcinoma, invasive carcinoma at ductal resection margins appears to have a strong adverse effect on patient survival, whereas residual carcinoma in situ does not.

The mitotic apparatus plays a pivotal role in dividing cells to ensure each daughter cell receives a full set of chromosomes and complement of cytoplasm during mitosis. A human homologue of the Drosophila warts tumor suppressor, h-warts/LATS1, is an evolutionarily conserved serine/threonine kinase and a dynamic component of the mitotic apparatus. We have identified an interaction of h-warts/LATS1 with zyxin, a regulator of actin filament assembly. Zyxin is a component of focal adhesion, however, during mitosis a fraction of cytoplasmic-dispersed zyxin becomes associated with h-warts/LATS1 on the mitotic apparatus. We found that zyxin is phosphorylated specifically during mitosis, most likely by Cdc2 kinase, and that the phosphorylation regulates association with h-warts/LATS1. Furthermore, microinjection of truncated h-warts/LATS1 protein, including the zyxin-binding portion, interfered with localization of zyxin to mitotic apparatus, and the duration of mitosis of these injected cells was significantly longer than that of control cells. These findings suggest that h-warts/LATS1 and zyxin play a crucial role in controlling mitosis progression by forming a regulatory complex on mitotic apparatus.