Elective colorectal cancer surgery in nonagenarians and postoperative outcomes.

OBJECTIVES: The population of very elderly patients is increasing, and nonagenarians have significantly higher mortality rates and poorer rates of survival than younger patients. Meanwhile, recent studies have shown colorectal cancer surgery in nonagenarian patients to be feasible regarding postoperative outcomes. This retrospective study aims to evaluate the postoperative outcomes of nonagenarians in the latest clinical settings. METHODS: Consecutive nonagenarian patients who underwent elective colorectal cancer surgery between 2018 and 2020 retrospectively enrolled (Trial registration number: UMIN000046296 on December 7th, 2021). Clinicopathological data and short-term postoperative outcomes were collected for statistical analysis. RESULTS: This study included 81 nonagenarian patients (31 males, 50 females). Postoperative complications occurred in 21 patients (25.9%), and 3 patients died within 90 days (3.7%). Multivariate analysis revealed prognostic nutritional index was a significant predictor of postoperative complications (OR 2.99, 95% CI 0.78-9.10, P = 0.048), and performance status ≥ 3 could be an independent risk factor of 90-day mortality (HR 32.30, 95% CI 3.20-326.10, P = 0.032). CONCLUSIONS: Short-term outcomes after surgical treatment for nonagenarian patients with colorectal cancer were acceptable. Low prognostic nutritional index was closely related to postoperative complications and poor performance status could also lead to 90-day mortality. In aging populations, risk stratification to prevent poorer postoperative outcomes in nonagenarian patients is needed.

Asymptomatic patent processus vaginalis is a risk for developing external inguinal hernia in adults: A prospective cohort study.

BACKGROUND: Inguinal hernia repair is common for children and adults across the world, but the mechanism behind hernia onset still requires elucidation. This prospective study aims to determine whether patent processus vaginalis (PPV) is a factor in the development of external inguinal hernias. METHOD: We enrolled 1008 patients who underwent laparoscopic surgery and in whom the inguinal region was observed. If processus vaginalis existed, we measured the diameter and length. Patients were followed for three years after surgery to investigate the incidence of external inguinal hernias. RESULT: No significant differences were found between age groups. Furthermore, no difference could be recognized in length or opening diameter of the PPVs between age groups. Three-year follow up was possible for 765 of 1008 patients enrolled in this study (76%), eight of whom, all male, developed external inguinal hernia during this period. Multivariate analysis for onset of inguinal hernia onset in male patients showed that PPV and length of the right PPV were independent risk factors for development of external inguinal hernia. CONCLUSION: The patency rate, length, and diameter of the processus vaginalis do not differ according to age. The patency of the processus vaginalis in male patients is an independent risk factor for development of external inguinal hernia in adults.

Intraoperative maneuvers may affect the development of early postoperative small bowel obstruction after laparoscopic colorectal cancer surgery: Multicenter prospective cohort study.

BACKGROUND: Early postoperative small bowel obstruction (EPSBO) is one of the most common complications after colorectal cancer (CRC) surgery, and clarification of its causes is desired. Several reports have demonstrated the risks of EPSBO, but few have focused on laparoscopic surgery for CRC and intraoperative maneuvers. We therefore prospectively examined the risk factors for EPSBO after laparoscopic CRC resection. METHODS: We prospectively enrolled 706 patients with CRC that underwent laparoscopic CRC resection in our hospital and affiliated hospitals. We analyzed several factors concerning EPSBO including intraoperative procedures. RESULTS: EPSBO developed in 43 of the 706 cases (6.1%). Univariate analysis showed that risk factors for EPSBO were male sex, increased operative time, repositioning of the small intestine before wound closure and anastomotic leakage. Risk factors for EPSBO according to multivariate analysis were increased operative time (odds ratio (OR) 2.41; P = 0.032), repositioning of the small intestine before wound closure (OR 3.58; P = 0.005) and anastomotic leakage (OR 3.91; P = 0.006). CONCLUSION: To reduce EPSBO after laparoscopic CRC surgery, the operation should be finished as soon as possible without performing optional maneuvers. To avoid development to EPSBO, particular care is required in cases where the risk of anastomotic leakage is predicted to be high.

Laparoscopic anterior resection with or without transanal tube for rectal cancer patients - A multicenter randomized controlled trial.

BACKGROUND: In rectal cancer surgery, insertion of transanal tube has been shown to have efficacy to prevent anastomotic leakage. This randomized controlled study aims to clarify the incidence of anastomotic leakage with or without transanal tube in patients with rectal cancer. METHODS: Patients who underwent elective low anterior resection were randomly allocated to either have transanal tube insertion or not for five days after surgery. We examined the incidence of anastomotic leakage, postoperative 30-day morbidity and mortality. RESULTS: 157 patients were randomized to the transanal tube group or the no-transanal tube group. Symptomatic anastomotic leakage occurred in six patients (7.6%) of the former group and eight patients (10.3%) in the latter group, without significant difference (p = 0.559). There was also no significant difference in morbidity between groups (p = 0.633) and no mortality was detected. CONCLUSIONS: Transanal tube insertion had no significant benefit towards prevention of anastomotic leakage in rectal cancer surgery.

Optimal Assessment of Frailty Predicts Postoperative Complications in Older Patients with Colorectal Cancer Surgery.

OBJECTIVES: The increasingly elderly worldwide population has affected the incidence of colorectal cancer. Establishment of reliable assessment of frailty and proposals for multi-disciplinary interventions are urgently required in oncology practices. Kihon Checklist (KCL) was published by the Japanese Ministry of Health, Labor and Welfare originally to identify individuals ≥ 65 years old at probable risk for requiring care or social support. We investigate the validity of KCL for frailty assessment to predict postoperative complication in older patients with colorectal cancer. METHODS: Consecutive colorectal cancer patients aged ≥ 65 (n = 500) were prospectively examined between May 2017 and December 2018. Preoperative frailty assessment was conducted by the G8 questionnaire and KCL. The main outcome measures were correlation between frailty, other clinical variables, and postoperative complications within 30 days after elective surgery. RESULTS: Of the 500 patients, 278 (55.6%) and 164 (32.8%) patients were classified as 'frail' by G8 and KCL, respectively. Overall complications counted among 97 patients (19.4%), and they were significantly associated with KCL ≥ 8-frail (46/164, p = 0.001), as opposed to G8 ≤ 14-frail (56/278, p = 0.531). Multivariate analysis showed that KCL ≥ 8 (hazard ratio 1.88, 95% confidence interval 1.16-3.04, p = 0.011) was an independent risk factor for these complications. CONCLUSIONS: KCL assessment can identify frail older patients likely to suffer from postoperative complications after colorectal cancer surgery. Preoperative screening of frailty, particularly by KCL, would help older patients prevent their worse outcomes in colorectal cancer. TRIAL REGISTRATION: UMIN000026689.

Circular stapling versus triangulating stapling for the cervical esophagogastric anastomosis after esophagectomy in patients with thoracic esophageal cancer: A prospective, randomized, controlled trial.

BACKGROUND: Several studies have reported that the triangulating stapling method decreases the incidence of anastomotic stricture after esophagectomy, but no randomized, controlled trial has confirmed the efficacy of the triangulating stapling method for cervical esophagogastrostomy. We compared triangulating stapling and circular stapling for cervical esophagogastric anastomosis regarding the decrease in anastomotic stricture after esophagectomy for thoracic esophageal cancer. METHODS: Between August 2010 and April 2014, 100 patients enrolled in this randomized, controlled trial at the Wakayama Medical University Hospital were allocated randomly to either the circular stapling group (n = 49) or the triangulating stapling group (n = 51). The primary end point was the incidence of anastomotic stricture within 12 months postoperatively. This randomized, controlled trial was registered with the University Hospital Medical Information Network Clinical Trial Registry (UMIN000004848). RESULTS: There were no differences between the circular stapling and triangulating stapling groups in terms of clinical data. The amount of time required for esophagogastric anastomosis was slightly greater for the triangulating stapling group (22 minutes) than for the circular stapling group (18 minutes) (P = .028). Anastomotic stricture occurred in 8 patients (17%) in the circular stapling group and 9 patients (19%) in the triangulating stapling group (P = .935). The rate of anastomotic leakage was 11% for the circular stapling group and 2% for the triangulating stapling group (P = .073). CONCLUSION: The triangulating stapling method for cervical anastomosis for thoracic esophageal cancer does not decrease the incidence of anastomotic stricture compared with the circular stapling method within 12 postoperative months but may affect the rate of anastomotic leakage.

The effects of rikkunshito on body weight loss after esophagectomy.

BACKGROUND: After esophagectomy, esophageal cancer patients suffer from malnutrition, anorexia, and dysfunction of digestion and absorption. Rikkunshito, a traditional Japanese herbal medicine, reportedly attenuates gastrointestinal symptoms and appetite loss after gastrointestinal surgery. We evaluated the clinical effect of rikkunshito and its relationship with ghrelin in esophageal cancer patients after esophagectomy. METHODS: This prospective nonrandomized study included 40 patients with esophageal cancer who underwent esophagectomy at Wakayama Medical University Hospital. They were assigned to either the control group (n = 20, April 2011-January 2012) or the rikkunshito group (n = 20, January 2012-August 2012). Patients in the rikkunshito group received 2.5 g of rikkunshito before every meal for 48 wk beginning 4 wk after surgery. During the 48-week treatment, we assessed body weight loss, nutritional parameters, and quality of life (Functional Assessment of Cancer Therapy-Esophageal scale). The primary end point was the rate of body weight loss in two groups after the 48-week treatments. RESULTS: The rate of body weight loss was significantly less in the rikkunshito group than in the control group (P = 0.016). The acyl ghrelin level after the 48-week treatments was significantly higher in the rikkunshito group (131.7% ± 74.5%) than in the control group (75.6% ± 47.5%, P = 0.039). For the Functional Assessment of Cancer Therapy-Esophageal symptom scale, satisfaction of food consumption in the rikkunshito group was significantly better than in the control group at 52 wk postoperatively (P = 0.031). CONCLUSIONS: For esophageal cancer patients after esophagectomy, rikkunshito is useful for improving body weight loss in connection with an increase in plasma acyl ghrelin levels.

Neoadjuvant Chemotherapy with Divided-dose Docetaxel, Cisplatin and Fluorouracil for Patients with Squamous Cell Carcinoma of the Esophagus.

BACKGROUND: The aim of this phase II study was to evaluate the feasibility of a neoadjuvant chemotherapy regimen consisting of divided-dose docetaxel and cisplatin, with 5-fluorouracil (NAC-DCF), for treatment of patients with stage II/III squamous cell carcinoma of the esophagus (SCCE). PATIENTS AND METHODS: The NAC-DCF regimen, consisting of 2-h infusion of docetaxel at 35 mg/m(2) on days 1 and 8, 4-h infusion of cisplatin at 12 mg/m(2) on days 1-5, and continuous infusion of 5-fluorouracil at 600 mg/m(2) on days 1-5, was administered. We compared NAC-DCF with conventional NAC-CF. RESULTS: The DCF group comprised of 45 patients, and the CF group comprised of 28 patients. The incidence of grade 3/4 neutropenia was significantly higher in the DCF group (56%) than in the CF group (0%). Grade 2/3 pathological response was attained in a significantly higher percentage of patients in the DCF group (40%) than in the CF group (11%) (p=0.0153). CONCLUSION: This DCF regimen led to a high frequency of pathological responses among patients with advanced SCCE.

Laparoscopic combined resection of synchronous gastric and colorectal cancer.

PURPOSE: The aim of this study was to examine the feasibility of performing combined laparoscopic resection in patients with synchronous gastric and colorectal cancer. METHODS: Thirty-six consecutive patients with synchronous gastric and colorectal cancer who underwent simultaneous combined resection were enrolled in this retrospective study. RESULTS: Six patients underwent laparoscopic combined resection (lap group), whereas the other 30 patients underwent conventional open combined surgery (open group). Although the operative time was longer in the lap group than in the open group, there were no differences in the amount of intraoperative bleeding. Although there were no differences in the rates of postoperative complications between the 2 groups, the postoperative hospital stay was significantly shorter in the lap group. During a mean follow-up of 35 months, all 6 patients who underwent laparoscopic combined resection survived without any signs of recurrence. CONCLUSIONS: Simultaneous laparoscopic resection is a feasible procedure in patients with synchronous gastric and colorectal cancer.

Reconstruction after proximal gastrectomy for early gastric cancer in the upper third of the stomach: an analysis of our 13-year experience.

BACKGROUND: Fundoplication during esophagogastrostomy (EG) after proximal gastrectomy (PG) is a useful procedure to prevent reflux esophagitis, but it is unclear how much of the remnant stomach should be wrapped around the esophagus. METHODS: We analyzed data from 101 patients who underwent PG for upper third early gastric cancer between 1999 and 2011. In all, 64 patients underwent EG, 25 underwent jejunal interposition (JI), and 12 underwent jejunal pouch interposition (JPI). We compared intraoperative details and postoperative outcomes, and investigated the relationships between the degree of the fundoplication during EG and endoscopic findings. RESULTS: The length of the operation was significantly shorter in the EG group than in the other 2 groups (P < .05), and the intraoperative blood loss was significantly less in the EG group (P < .05). The JI and the JPI groups had significantly greater rates of early complications than did the EG group (P = .01). Reflux esophagitis was present in 22% of patients in the EG group, 8% in the JPI group, and none in the JI group. In the EG group, reflux esophagitis was significantly less common in patients with a >180° wrap of the remnant stomach around the esophagus than in patients with a smaller wrap (P = .0008). The rate of body weight loss was significantly less in the EG group compared with the other 2 groups (P < .05). CONCLUSION: Considering the low invasiveness of the procedure and postoperative outcomes, we consider that EG with a >180° wrap as the optimal reconstructive procedure.

Complications of endoscopic submucosal dissection for gastric noninvasive neoplasia: an analysis of 647 lesions.

PURPOSE: This study aimed to determine risk factors for postoperative complications of gastric endoscopic submucosal dissection (ESD). METHODS: This retrospective study included 647 lesions in 580 consecutive patients who underwent ESD for gastric noninvasive neoplasia from January 1, 2002 through December 31, 2011. RESULTS: The overall perforation rate was 5.1%. Multivariate logistic regression analysis indicated that perforation was significantly associated with tumors in the greater curvature of the stomach (P<0.0001), scars in tumor lesions (P=0.002), long operative time (P=0.007), and tumors in the remnant stomach (P=0.036). The bleeding rate after gastric ESD was 3.9%. Multivariate logistic regression analysis indicated a statistically significant association between postoperative bleeding and oral anticoagulant or antiplatelet drugs (P<0.0001), dialysis (P=0.009), and use of antihypertensive drugs (P=0.015). CONCLUSION: It is important to perform gastric ESD with particular care in patients with risk factors.

Endoscopic submucosal dissection for gastric tumors in various types of remnant stomach.

BACKGROUND AND STUDY AIMS: The aim of this study was to examine the clinical outcomes of endoscopic submucosal dissection (ESD) for gastric tumors in various types of remnant stomach. PATIENTS AND METHODS: Between January 2002 and March 2013, ESD was performed for 750 gastric tumors. Of these lesions, 49 were in a remnant stomach, and were included in the study. RESULTS: The en bloc resection rate was 100 %. The curative resection rate was 82 %. The rate of perforation was high in patients with gastric conduits (28.6 %). Perforation was significantly more common in patients with lesions located on the suture line (4.9 % vs. 50.0 %; P = 0.0043). CONCLUSION: ESD for gastric tumors in the remnant stomach can be considered feasible and safe in clinical practice. However, the procedure is technically more difficult in patients with a gastric conduit, due to the increased risk of perforation at the suture line.

Is preoperative colonoscopy necessary for patients undergoing gastric cancer surgery?

PURPOSE: The aim of this study was to evaluate the necessity of preoperative colonoscopy (CS) in gastric cancer (GC) patients and to assess the outcomes of different treatments in patients with synchronous GC and colorectal neoplasms (CRN). We also determined the risk factors influencing the comorbidity of colorectal cancer (CRC) in patients with GC. METHODS: This retrospective study included 1891 consecutive GC patients who underwent CS before surgery from January 1, 1999, through June 30, 2012. RESULTS: There was a high prevalence of concurrent CRN (28.4 %) and CRC (3.2 %) in our patients with GC. Sixty-one patients with GC had synchronous CRC. Twenty-three of the 61 tumors were perioperatively treated by endoscopic resection. The other 38 tumors were treated by simultaneous surgery for the GC and CRC. Surgical complications were not found in either the endoscopic or surgical resection group. The multivariate logistic regression analysis indicated that the prevalence of synchronous CRC in patients with GC was significantly associated with the incidence of multiple GCs [P < 0.0001; odds ratio (OR) 15.3], having anemia (P = 0.002; OR 3.0), and having a smoking history (P = 0.021; OR 1.9). CONCLUSIONS: We recommend preoperative CS screening for GC patients. In particular, preoperative CS screening is indispensable for patients with multiple GCs. In addition, simultaneous treatments for patients with synchronous GC and CRN are safe and feasible procedures.

Identification of an HLA-A2-restricted epitope peptide derived from hypoxia-inducible protein 2 (HIG2).

We herein report the identification of an HLA-A2 supertype-restricted epitope peptide derived from hypoxia-inducible protein 2 (HIG2), which is known to be a diagnostic marker and a potential therapeutic target for renal cell carcinoma. Among several candidate peptides predicted by the HLA-binding prediction algorithm, HIG2-9-4 peptide (VLNLYLLGV) was able to effectively induce peptide-specific cytotoxic T lymphocytes (CTLs). The established HIG2-9-4 peptide-specific CTL clone produced interferon-γ (IFN-γ) in response to HIG2-9-4 peptide-pulsed HLA-A*02:01-positive cells, as well as to cells in which HLA-A*02:01 and HIG2 were exogenously introduced. Moreover, the HIG2-9-4 peptide-specific CTL clone exerted cytotoxic activity against HIG2-expressing HLA-A*02:01-positive renal cancer cells, thus suggesting that the HIG2-9-4 peptide is naturally presented on HLA-A*02:01 of HIG-2-expressing cancer cells and is recognized by CTLs. Furthermore, we found that the HIG2-9-4 peptide could also induce CTLs under HLA-A*02:06 restriction. Taken together, these findings indicate that the HIG2-9-4 peptide is a novel HLA-A2 supertype-restricted epitope peptide that could be useful for peptide-based immunotherapy against cancer cells with HIG2 expression.

Atrial fibrillation after esophageal cancer surgery: an analysis of 207 consecutive patients.

PURPOSE: The aim of this study was to identify perioperative risk factors that are associated with postoperative atrial fibrillation (AF) and the outcomes of different pharmacological interventions in esophageal cancer patients who underwent transthoracic esophagectomy. METHODS: This study included 207 patients who underwent a transthoracic esophagectomy for esophageal cancer resection by a single surgeon from January 1, 2004, through December 31, 2010. RESULTS: Postoperative AF occurred in 19 patients (9.2 %), all of whom received antiarrhythmic drug therapy at the early stage. Antiarrhythmic treatment was effective in 12 cases (63.2 %). In this study, landiolol hydrochloride, an ultrashort-acting ß1-selective ß-blocker, was the first-line therapy for postoperative AF. A multivariate logistic regression analysis showed that postoperative AF was significantly associated with the use of an ileo-colon for reconstruction after esophagectomy (P = 0.0023, odds ratios [OR] = 13.6) and with the presence of tachycardia with a heart rate of >100 bpm on postoperative day (POD) 1 (P = 0.0004, OR = 18.4). CONCLUSIONS: Postoperative AF is associated with the use of a colon conduit for reconstruction after esophagectomy and with tachycardia with a heart rate >100 bpm on POD 1. Identifying patients at high risk for postoperative AF will allow for more direct application of pharmacological methods of prophylaxis.

Clinical benefits of thoracoscopic esophagectomy in the prone position for esophageal cancer.

PURPOSES: The clinical benefits of thoracoscopic radical esophagectomy in the prone position compared to conventional open esophagectomy have not been fully documented. METHODS: Forty-six patients with esophageal cancer who underwent MIE in the prone position (MIE-P group) were enrolled, and 46 case-matched controls that underwent open esophagectomy (OE group) were identified using propensity score methods to achieve a valid comparison of outcomes between MIE and open esophagectomy. RESULTS: The duration of systemic inflammatory response syndrome was shorter in the MIE-P group than in OE group (P = 0.005). The time to first walking was earlier in the MIE-P group (P < 0.001). Although the vital capacity ratio (%VC) declined after the operation in both groups, the change ratio of the %VC was 85.3% in the MIE-P group and 69.6% in the OE group (P < 0.001). No mortality occurred in either group. The postoperative morbidity rate was lower in the MIE-P group (13%) than in the OE group (30.4%) (P = 0.020). Two patients (4.3%) in the OE group and one patient in the MIE-P group (2.2%) had pneumonia. CONCLUSIONS: MIE in the prone position was associated with less impairment of the pulmonary function, earlier recovery of activity and lower subsequent morbidity compared to open esophagectomy. Further investigation of the long-term outcomes is, therefore, needed.

Prognostic significance of IL-17 mRNA expression in peritoneal lavage in gastric cancer patients who underwent curative resection.

Peritoneal dissemination is frequently detected in patients with advanced gastric cancer. The peritoneal cavity is a compartment in which an immunologic host-tumor interaction can occur. There are no reports on the relationship between IL-17 expression in peritoneal lavage and prognosis in gastric cancer patients. Therefore, we investigated the expression of IL-17 mRNA in peritoneal lavage from gastric cancer patients and assessed the association of its expression with clinicopathological parameters and prognosis. Peritoneal lavage was obtained from 114 patients with gastric cancer at initial surgery. Seventy-nine patients underwent curative resection. Among these 79 patients, IL-17 mRNA expression was associated with the depth of tumor invasion (p<0.05). Twelve of the 79 patients who underwent curative resection died, and 9 of those 12 developed peritoneal metastasis. Notably, among the 79 patients who underwent curative resection, those with high expression of IL-17 mRNA in peritoneal lavage had significantly prolonged survival when compared to these patients with low expression of IL-17 mRNA in peritoneal lavage (p<0.05) as evidence by the survival curves. In a multivariate analysis, low expression of IL-17 mRNA in peritoneal lavage and tumor size were found to be independent significant predictive factors for prognosis (HR, 7.91; 95% CI, 1.65-38.03) in the patients who underwent curative resection. IL-17 mRNA expression in peritoneal lavage is a reliable prognostic factor for patients undergoing curative resection for gastric cancer. Low IL-17 expression in the peritoneal cavity may correlate with cancer development in the peritoneal cavity in patients with gastric cancer.

Induction of a pathological complete response by four courses of neoadjuvant chemotherapy for gastric cancer: early results of the randomized phase II COMPASS trial.

BACKGROUND: The prognosis for stage 3 gastric cancer is not satisfactory, even with S-1 adjuvant chemotherapy. A randomized phase II trial was conducted to compare two and four courses of neoadjuvant S-1/cisplatin (SC) and paclitaxel/cisplatin (PC) using a two-by-two factorial design for locally advanced gastric cancer. The primary endpoint was overall survival. We clarified the impact of these regimens on the secondary endpoints, including the clinical and pathological responses, chemotherapy-related toxicities, and surgical results. METHODS: Patients received S-1 (80 mg/m(2) for 21 days with 1 week's rest)/cisplatin (60 mg/m(2) at day 8) or paclitaxel/cisplatin (80 and 25 mg/m(2), respectively, on days 1, 8, and 15 with 1 week's rest) as neoadjuvant chemotherapy. RESULTS: Eighty-three patients were assigned to arm A (two courses of SC, n = 21), arm B (four courses of SC, n = 20), arm C (two courses of PC, n = 21), and arm D (four courses of PC, n = 21). Pathological response rate was 43 % in arm A, 40 % in arm B, 29 % in arm C, and 38 % in arm D. Pathological complete response was only observed in arms B (10 %) and D (10 %). Most bone marrow toxicities, nausea, vomiting, alopecia, and fatigue were slightly higher but acceptable in arms B and D. Grade 3/4 surgical morbidities were not commonly observed in all four arms. CONCLUSIONS: Pathological complete response could be induced by four courses of neoadjuvant chemotherapy without a marked increase of toxicities, regardless of a SC or PC regimen.

Antitumor immune response of dendritic cells (DCs) expressing tumor-associated antigens derived from induced pluripotent stem cells: in comparison to bone marrow-derived DCs.

It is generally accepted that the difficulty in obtaining a sufficient number of functional dendritic cells (DCs) is a serious problem in DC-based immunotherapy. Therefore, we used the induced pluripotent stem (iPS) cell-derived DCs (iPSDCs). If the therapeutic efficacy of iPSDCs is equivalent to that of bone marrow-derived DCs (BMDCs), then the aforementioned problems may be solved. In our study, we induced iPSDCs from iPS cells and examined the capacity for maturation of iPSDCs compared to that of BMDCs in addition to the capacity for migration of iPSDCs to regional lymph nodes. We adenovirally transduced the hgp100 gene, natural tumor antigens, into DCs and immunized mice once with the genetically modified DCs. The cytotoxic activity of CD8 (+) cytotoxic T lymphocytes (CTLs) was assayed using a (51) Cr-release assay. The therapeutic efficacy of the vaccination was examined in a subcutaneous tumor model. Our results showed that iPSDCs have an equal capacity to BMDCs in terms of maturation and migration. Furthermore, hgp100-specific CTLs were generated in mice immunized with genetically modified iPSDCs. These CTLs exhibited as high a level of cytotoxicity against B16 cells as BMDCs. Moreover, vaccination with the genetically modified iPSDCs achieved as high a level of therapeutic efficacy as vaccination with BMDCs. Our study clarified experimentally that genetically modified iPSDCs have an equal capacity to BMDCs in terms of tumor-associated antigen-specific therapeutic antitumor immunity. This vaccination strategy may therefore be useful for future clinical application as a cancer vaccine.