Risk factors for anastomotic leakage after low anterior resection for obese patients with rectal cancer.

PURPOSE: We aimed to analyze the risk factors for anastomotic leakage (AL) after low anterior resection (LAR) in obese patients (body mass index [BMI] ≥ 25 kg/m2) with rectal cancer. METHODS: Data were collected from four hundred two obese patients who underwent LAR for rectal cancer in 51 institutions. RESULTS: Forty-six (11.4%) patients had clinical AL. The median BMI (27 kg/m2) did not differ between the AL and non-AL groups. In the AL group, comorbid respiratory disease was more common (p = 0.025), and the median tumor size was larger (p = 0.002). The incidence of AL was 11.5% in the open surgery subgroup and 11.4% in the laparoscopic surgery subgroup. Among the patients who underwent open surgery, the AL group showed a male predominance (p = 0.04) in the univariate analysis, but it was not statistically significant in the multivariate analysis. Among the patients who underwent laparoscopic surgery, the AL group included a higher proportion of patients with comorbid respiratory disease (p = 0.003) and larger tumors (p = 0.007). CONCLUSION: Comorbid respiratory disease and tumor size were risk factors for AL in obese patients with rectal cancer. Careful perioperative respiratory management and appropriate selection of surgical procedures are required for obese rectal cancer patients with respiratory diseases.

Timing of re-dosing based on population pharmacokinetic-pharmacodynamics target attainment analysis of cefmetazole in subjects undergoing lower gastrointestinal surgery.

INTRODUCTION: This study was conducted to evaluate the population pharmacokinetics of prophylactic cefmetazole sodium (CMZ) based on the serum concentrations and establish a pharmacodynamics target concentration exceeding the minimum inhibitory concentration (MIC) to design the re-dosing interval. METHODS: Serum (n = 362) samples from 107 individuals were analyzed using a nonlinear mixed-effects model. The pharmacodynamics index obtained was regarded as the probability of maintaining CMZ serum trough exceeding the minimal inhibitory concentration (MIC) of 2 mg/L. This MIC was chosen to account for methicillin-susceptible Staphylococcus aureus (MSSA), E. coli, and Klebsiella pneumoniae RESULTS: The final population pharmacokinetic model was a two-compartment model with linear elimination. Creatinine clearance and body weight were identified as significant covariates influencing the central clearance and volume of distribution in the central compartment. The probability of achieving serum concentrations exceeding the MIC90 for MSSA, E. coli, and Klebsiella pneumoniae for a 1 g dose with a 10 min intravenous infusion was above 90% except for good renal function (CLcr â‰§ 95 mL/min) at 2 h after the initial dose. For patients with good renal function (CLcr â‰§ 95 mL/min), a CMZ of 2 g re-dosing interval seemed necessary to meet the achievement probability. In patients with impaired renal function (CLcr ≤20 mL/min), the probability of achievement exceeded 90% even when the dosing interval was extended to 8 h. CONCLUSIONS: We evaluated re-dosing intervals based on the population pharmacokinetics. Re-dosing intervals should be determined based on renal function.

A multicentre confirmatory single-arm trial of the safety and efficacy of a transanal drain for prevention of anastomotic leakage after surgery for rectal cancer.

AIM: Recent reports have described the use and efficacy of several types of transanal tube (TAT) for preventing anastomotic leakage by reducing intraluminal pressure. The aim of this study was to evaluate the safety and efficacy of a newly developed TAT for the prevention of anastomotic leakage after low anterior resection (LAR) for rectal cancer. METHOD: A multicentre confirmatory single-arm trial was designed to evaluate the safety and efficacy of a new TAT after LAR for rectal cancer. A total of 115 patients were registered in the trial at several cancer centres and other hospitals. All patients initially received reconstruction with a stapled anastomosis, but 18 then underwent creation of a diverting stoma. Of the remaining 97 patients, the first 96 were included in the protocol-defined primary analysis set. The primary outcome was the incidence of symptomatic leakage and the secondary endpoint was the incidence of complications associated with use of the TAT. The TAT was placed during LAR without creating a covering stoma and the drain was removed 4 or 5 days postoperatively. RESULTS: The rate of symptomatic leakage was 5.2% (95% confidence interval 1.7-11.7), which was significantly lower than the predetermined threshold value of 15.8% (one-sided p-value 0.0013). Only one patient had Grade 3 rectal bleeding that might have been related to use of the TAT. CONCLUSION: This nonrandomized study shows that the TAT appears to be safe and results in lower rates of anastomotic leakage in LAR compared with previous studies.

Examination of the efficacy of olanexidine gluconate for surgical site infections in colorectal cancer elective surgery.

INTRODUCTION: The preoperative skin antiseptic, olanexidine gluconate (OLG), which has been available in Japan since 2015, is also known to be effective against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and Pseudomonas aeruginosa. This study attempted to clarify OLG efficacy against surgical site infections and antiseptic-related adverse events as compared to conventionally used povidone iodine (PVP-I). METHODS: Propensity score matching was performed on 307 patients who underwent surgery for colorectal tumors at our hospital. All 116 cases (58 PVP-I cases, 58 OLG cases) who were diagnosed with colorectal cancer were included. We examined surgical site infection rate after disinfection using PVP-I and OLG, length of hospitalization stay (days) after surgery, adverse events associated with antiseptics, and additional medical costs associated with adverse events caused by antiseptics. RESULTS: The surgical site infection rate was 8.6% in both the PVP-I and OLG groups, with no significant difference observed. The number of postoperative hospitalization days in the PVP-I group was 12.9 (±6.9) days and 16.4 (±14.6) days in the OLG group, which exhibited no significant difference (p = 0.10). Although no complications due to antiseptics were observed in the PVP-I group, skin-related side effects were observed in 8 patients (13.8%) in the OLG group. The median additional medical cost was 730 [120-1823] yen. CONCLUSIONS: OLG was as effective as the conventional PVP-I for surgical site infections during colorectal cancer elective surgery. However, significantly higher skin disorders occurred in OLG, thereby making it necessary to evaluate antiseptic use in conjunction with patient burden.

[A Case of Low-Grade Appendiceal Mucinous Neoplasm for Which Laparoscopic Surgery Was Effective].

Abdominal ultrasonography during a regular medical examination showed that a 70-year-old man had an approximately 10 cm cystic tumor in the lower abdomen. Abdominal computed tomography showed that the appendix had swollen to a size of 130 mm×44 mm. As no other tests suggested malignancy, the patient's condition was diagnosed as a low-grade appendiceal mucinous tumor and he underwent laparoscopic ileocecal resection and lymph node D2 dissection. Laparoscopic surgery was completed without damaging the tumor. There has been no recurrence after the operation for 2 years now.

[Long-Term Clinical Complete Response after Preoperative Chemoradiotherapy in a Patient with Locally Advanced, Lower Rectal Cancer].

A 77-year-old woman underwent preoperative chemoradiotherapy for rectal cancer in the Rb region(3 cm from the anal verge). The treatment regimen consisted of tegafur, gimeracil, and oteracil potassium(80 mg/m2/day, administered on days 1 to 5)and irinotecan(80 mg/m2, administered on day 1). A 1-week regimen was regarded a 1 course. In total, 4 courses were administered. Radiotherapy was administered with a margin of 1 cm around the tumor, with a daily dose of 1.8 Gy for 25 days. After treatment, evaluations were performed. Lower gastrointestinal endoscopy, barium enema examination, and computed tomography of the chest and abdomen were performed at 6 to 7 weeks, and a clinical complete response was observed. At the patient's request, we decided to carefully follow-up the patient. Currently, 10 years 8 months after treatment, the patient still has a clinical complete response.

WiNTRLINC1/ASCL2/c-Myc Axis Characteristics of Colon Cancer with Differentiated Histology at Young Onset and Essential for Cell Viability.

BACKGROUND: WiNTRLINC1 is a long non-coding RNA (lncRNA) that positively regulates the Wnt pathway via achaete-scute complex homolog 2 (ASCL2) in colorectal cancer. ASCL2 was recently reported to play a critical role in chemoresistance, however clinical relevance of the WiNTRLINC1/ASCL2 axis remains obscure in colon cancer. PATIENTS AND METHODS: WiNTRLINC1/ASCL2 expression was investigated at messenger RNA (mRNA) level in 40 primary colon cancer tissues and the corresponding normal mucosa tissues, together with Wnt-related genes (c-Myc/PRL-3) and other lncRNAs (H19, HOTAIR, and MALAT1). Knock-down experiments of WiNTRLINC1 clarified its role in their expression and chemoresistance. RESULTS: Real-time quantitative reverse transcriptase-polymerase chain reaction confirmed definite overexpression of WiNTRLINC1 mRNA in primary colon cancer compared with the corresponding normal colon mucosa tissues (p = 0.0005), such as ASCL2, c-Myc, and PRL-3 (p < 0.0001). The four gene expression signatures were tightly associated in the center of the ASCL2 gene (r = 0.72, p < 0.0001) in clinical samples. WiNTRLINC1 was not significantly associated with prognostic factors in colon cancer and other lncRNAs, while the WiNTRLINC1/ASCL2/c-Myc signatures were unique to young-onset colon cancer with differentiated histology. On the other hand, undifferentiated histology was significantly associated with H19 expression. Knockdown of the WiNTRLINC1 gene reduced the expression of ASCL2/c-Myc, but rather augmented PRL-3 at mRNA level, and robustly affected cell viability in colon cancer cell lines. CONCLUSION: The enhanced WiNTRLINC1/ASCL2/c-Myc axis involved in Wnt pathway activation is a common pathway essential for differentiated colon tumorigenesis, especially with young onset, and may be essential for a viable phenotype of colon cancer.

Epigenetic Status of CDO1 Gene May Reflect Chemosensitivity in Colon Cancer with Postoperative Adjuvant Chemotherapy.

BACKGROUND: Cysteine dioxygenase type 1 (CDO1) acts as a tumor suppressor gene, and its expression is regulated by promoter DNA methylation in human cancer. The metabolic product mediated by CDO1 enzyme increases mitochondrial membrane potential (MMP), putatively representing chemoresistance. The aim of this study is to investigate the functional relevance of CDO1 gene in colon cancer with chemotherapy. PATIENTS AND METHODS: We investigated 170 stage III colon cancer patients for CDO1 methylation by using quantitative methylation-specific polymerase chain reaction (PCR). To elucidate the functional role of CDO1 gene in colorectal cancer (CRC) biology, we established cell lines that stably express CDO1 gene and evaluated chemosensitivity, MMP, and tolerability assay including anaerobic environment. RESULTS: Hypermethylation of CDO1 gene was an independent prognostic factor for stage III colon cancer on multivariate prognostic analysis. Surprisingly, patients with CDO1 hypermethylation exhibited better prognosis than those with CDO1 hypomethylation in stage III colon cancer with postoperative chemotherapy (P = 0.03); however, a similar finding was not seen in those without postoperative chemotherapy. In some CRC cell lines, forced expression of CDO1 gene increased MMP accompanied by chemoresistance and/or tolerance under hypoxia. CONCLUSION: CDO1 methylation may be a useful biomarker to increase the number of stage III colon cancer patients who can be saved by adjuvant therapy. Such clinical relevance may represent the functionally oncogenic property of CDO1 gene through MMP activity.

Comprehensive Genetic Search to Clarify the Molecular Mechanism of Drug Resistance Identifies ASCL2-LEF1/TSPAN8 Axis in Colorectal Cancer.

BACKGROUND: Treatment-resistance genes limiting anticancer therapy have not been well clarified in colorectal cancer (CRC). We explored gene expression profiles to identify biomarkers for predicting treatment resistance to an anticancer drug in CRC. METHODS: Six CRC cell lines were treated with phenylbutyrate (PB). The gene expression profiles were then compared using microarrays (harboring 54,675 genes), and genes associated with PB resistance were identified. Candidate genes were functionally examined in cell lines and clinically validated for treatment resistance in clinical samples. RESULTS: Both DLD1 and HCT15 cells were PB resistant, while HCT116 cells were identified as PB sensitive. On microarray analysis, among the PB resistance-related genes, the expression of the genes ASCL2, LEF1, and TSPAN8 was clearly associated with PB resistance. PB-sensitive cells transfected with one of these three genes exhibited significant (P < 0.001) augmentation of PB resistance; ASCL2 induced expression of both LEF1 and TSPAN8, while neither LEF1 nor TSPAN8 induced ASCL2. RNA interference via ASCL2 knockdown made PB-resistant cells sensitive to PB and inhibited both genes. ASCL2 knockdown also played a critical role in sensitivity to treatment by 5-fluorouracil and radiotherapy in addition to PB. Finally, ASCL2 expression was significantly correlated with histological grade of rectal cancer with preoperative chemoradiation therapy. CONCLUSIONS: ASCL2 was identified as a causative gene involved in therapeutic resistance against anticancer treatments in CRC.

Laparoscopic surgery for locally advanced T4 colon cancer: the long-term outcomes and prognostic factors.

PURPOSE: For locally advanced pathological T4 (pT4) colon cancer, the safety and feasibility of laparoscopic procedures remain controversial. Therefore, this study aimed to assess short-term and long-term outcomes and to identify the prognostic factors in laparoscopic surgery for pT4 colon cancer. METHODS: The study group included 130 patients who underwent laparoscopic radical resection for pT4 colon and rectosigmoid cancer from January 2004 through December 2012. The short-term outcomes, long-term outcomes, and prognostic factors in pT4 colon cancer were analyzed. RESULTS: The median operative time was 205 min, with a median blood loss of 10 ml. The conversion rate was 3.8%, and 13 patients (10.0%) had postoperative complications. The radial resection margin was positive in 1 patient (0.8%). The median follow-up time was 73 months. The 5-year overall survival (OS) and recurrence-free survival (RFS) were 77.2 and 63.5%, respectively. On a multivariate analysis, a male sex [hazard ratio (HR) 3.09, p < 0.001], lymph node ratio ≥ 0.06 (HR 2.35, p = 0.021), tumor diameter < 38 mm (HR 2.57, p = 0.007), and right-sided colon cancer (HR 2.11, p = 0.047) were significantly related to a poor OS. CONCLUSIONS: These results suggest that laparoscopic surgery for pT4 colon cancer is safe and feasible, and the oncological outcomes are acceptable. Based on the present findings, select patients with locally advanced colon cancer should not be excluded from laparoscopic surgery.

Effect of Preoperative Nutritional Status on Surgical Site Infection in Colorectal Cancer Resection.

BACKGROUND/AIMS: Postoperative complications of colorectal cancer (CRC) can sometimes be life threatening. Prevention of morbidity is therefore the most important issue, and among such complications, surgical site infections (SSIs) are the most critical. Predictive factors for SSI were evaluated. PATIENTS AND METHODS: This was a retrospective study of 432 patients with CRC. SSIs were classified into incisional SSIs (iSSIs) and organ/space SSIs (o/sSSIs). RESULTS: Preoperative serum albumin (relative risk (RR) 2.51, p = 0.01) and body mass index (BMI: RR 2.36, p = 0.02) were the independent risk factors for iSSIs, while rectal cancer (RR 6.34, p < 0.0001), preoperative serum albumin (RR 7.03, p = 0.004), age (RR 2.71, p = 0.02), and male sex (RR 2.41, p = 0.05) were the independent risk factors for o/sSSIs. Patients with both low serum albumin and high BMI had the highest incidence of iSSIs (34.2%), and the group with rectal cancer and low serum albumin had the highest incidence of o/sSSIs (57.1%). CONCLUSIONS: Preoperative nutritional status is a risk factor for SSIs in CRC, and its proper preoperative management may reduce the risk of SSIs.

Risk factors for complications after diverting ileostomy closure in patients who have undergone rectal cancer surgery.

PURPOSE: To clarify the risk factors for complications after diverting ileostomy closure in patients who have undergone rectal cancer surgery. METHODS: The study group comprised 240 patients who underwent a diverting ileostomy at the time of lower anterior resection or internal anal sphincter resection, in our department, between 2004 and 2015. Univariate and multivariate analyses of 18 variables were performed to establish which of these are risk factors for postoperative complications. RESULTS: The most common complications were intestinal obstruction and wound infection. Univariate analysis showed that an age of 72 years or older (p = 0.0028), an interval between surgery and closure of 6 months or longer (p = 0.0049), and an operation time of 145 min or longer (p = 0.0293) were significant risk factors for postoperative complications. Multivariate analysis showed that age (odds ratio, 3.4236; p = 0.0025), the interval between surgery and closure (odds ratio, 3.4780; p = 0.0039), and operation time (odds 2.5179; p = 0.0260) were independent risk factors. CONCLUSIONS: Age, interval between surgery and closure, and operation time were independent risk factors for postoperative complications after diverting ileostomy closure. Thus, temporary ileostomy closure should be performed within 6 months after surgery for rectal cancer.

[Treatment Strategy for Liver Metastasis of Colorectal Cancer - Including Treatment for Oligometastasis].

The mainstay of treatment for metastatic colorectal cancer is surgery. Therefore, colorectal cancer metastasis is distinctive, compared to other cancer types in which chemotherapy is the main treatment. Initially, Japan experienced medical druglag compared with western countries. However, the use of oxaliplatin for unresectable recurrent metastatic colorectal cancer became available in Japan, as well as in western countries, in 2005. We have since shifted chemotherapeutic regimens from monotherapy to combination therapy with molecular targeted agents. The combination therapy has rapidly become a standard therapy for unresectable metastatic colorectal cancer, and prognosis has dramatically increased for patients with this condition. Herein, we describe the treatment of liver metastasis of colorectal cancer, and surgery and adjuvant or neoadjuvant therapy options for resectable cancer. Furthermore, we focus on conversion therapy for unresectable cancer.

[A Patient Who Underwent Resection of Liver Metastases after Receiving Systemic Chemotherapy for Advanced Rectal Cancer and Multiple Liver Metastases].

The patient was a 52-year-old man who had a positive fecal occult-blood test on a medical check-upi n April 2015 and was referred to our hospital in June. Detailed preoperative examinations resulted in a diagnosis of cancer of the lower rectum, multiple liver metastases, and clinical Stage IV . A biopsy showed moderately differentiated tubular adenocarcinoma. All-RAS was wild type, and the patient was asymptomatic. Unresectable advanced rectal cancer was diagnosed, and the patient was scheduled to receive systemic chemotherapy. The patient received a total of 16 courses of combination chemotherapy with 5- fluorouracil, Leucovorin, and oxaliplatin(FOLFOX)plus panitumumab, starting in October 2015. In July 2016, Colonoscopy showed scar findings at the site of the primary rectal cancer lesion. A biopsy revealed no cancer cells. It was difficult to identify the primary lesion on computed tomography, and there was no evidence of clinically significant lymphadenopathy. Positronemission tomography and computed tomography showed shrinkage of the liver metastases, with no accumulation of tracer in the primary lesion or lymph nodes. The primary lesion had a clinical complete response(CR), and the metastatic lesions had a clinical partial response(PR). In October 2016, laparoscopic partial hepatectomy was performed to treat the liver metastases. Histologic examination showed that the liver metastases were from rectal cancer. It is currently under observation.

Root respiratory costs of ion uptake, root growth, and root maintenance in wetland plants: efficiency and strategy of O2 use for adaptation to hypoxia.

Oxygen use in roots is an important aspect of wetland plant ecophysiology, and it depends on the respiratory costs of three major processes: ion uptake, root growth, and root maintenance. However, O2 allocation in wetland plants has received little attention. This study aimed to determine the O2 allocation and specific respiratory cost of each process under hypoxic conditions, to better understand the strategy and efficiency of O2 use in wetland plants. The root respiration rate, nitrogen uptake, and root growth in three Carex species with different growth rates were examined under hypoxic conditions using different N sources, and the respiratory costs of ion uptake, root growth, and root maintenance were statistically estimated. All species exhibited low specific costs and low ratios of O2 allocation for root growth (2.0 ± 0.4 mmol O2 g(-1) and 15.2 ± 2.7 %, respectively). The specific cost of ion uptake was 20-30 % lower in fast-growing species than in slow-growing species. As plant growth rate increased, the O2 allocation ratio for ion uptake increased, and that for root maintenance decreased. The cost was higher when NO3 (-) was fed, than when NH4 (+) was fed, although the pattern of O2 allocation ratios for three processes was similar for NO3 (-) and NH4 (+). Our results indicate that wetland plants primarily employ an O2 use strategy of minimising the respiratory costs of root growth, and fast-growing plants specifically use O2 to maximise ion uptake. These findings provide new insights into ecophysiological behaviours of roots in adaptation to hypoxia.

Risk Factors for Stoma Outlet Obstruction after Proctocolectomy for Ulcerative Colitis.

Objectives: Stoma outlet obstruction (SOO) occurs with an incidence of approximately 40% after proctocolectomy for Ulcerative colitis (UC) with diverting ileostomy. This study aimed to identify the risk factors for SOO after proctocolectomy with diverting ileostomy for patients with UC. Methods: We reviewed the data of 68 patients with UC who underwent proctocolectomy and diverting ileostomy between April 2006 and September 2021. These cases were analyzed on the basis of clinicopathological and anatomical factors. SOO was defined as small bowel obstruction displaying symptoms of intestinal obstruction, such as abdominal distention, abdominal pain, insertion of a tube through the stoma. Results: The study included 38 (56%) men and 30 (44%) women with a median age of 42 years (range, 21-80). SOO categorized as at least Clavien-Dindo grade II occurred in 11 (16%) patients. Six patients required earlier stoma closure than scheduled. Compared with patients without SOO, patients with SOO had a significantly higher total steroid dose from the onset of UC to surgery (p = 0.02), a small amount of intraabdominal fat (p = 0.04), and a higher rate of laparoscopic surgery (p < 0.01). Conclusions: A high preoperative steroid dose, a small amount of intraabdominal fat and laparoscopic surgery were identified as risk factors for SOO. Early detection and treatment for SOO are important for patients at risk.

Clinical influence of prophylactic lateral lymph node dissection on oncologic outcomes of patients with mid-low rectal cancer undergoing mesorectal excision: a meta-analysis.

BACKGROUND: Although several recent meta-analyses have investigated the clinical influence of the addition of lateral lymph node dissection (LLND) on oncologic outcomes in patients with mid-low rectal cancer (RC) undergoing mesorectal excision (ME), most studies included in such meta-analyses were retrospectively designed. Therefore, this study aimed to explore the clinical influence of prophylactic LLND on oncologic outcomes in patients with mid-low RC undergoing ME. METHODS: A comprehensive electronic search of the literature up to July 2022 was performed to identify studies that compared oncologic outcomes between patients with mid-low RC undergoing ME who underwent LLND and patients with mid-low RC undergoing ME who did not undergo LLND. A meta-analysis was performed using fixed-effects models and the generic inverse variance method to calculate hazard ratios (HRs) and 95% CIs, and heterogeneity was analyzed using I2 statistics. RESULTS: A total of 6 studies, consisting of 3 randomized and 3 propensity score matching studies, were included in this meta-analysis. The results of the meta-analysis of 2 randomized studies demonstrated no significant effect of prophylactic LLND on improving oncologic outcomes concerning overall survival (OS) (HR, 1.22; 95% CI, 0.89-1.69; I2 = 0%; P = .22) and relapse-free survival (RFS) (HR, 1.03; 95% CI, 0.81-1.31; I2 = 28%; P = .83). CONCLUSION: The results of this meta-analysis revealed no significant influence of prophylactic LLND on oncologic outcomes-OS and RFS-in patients with mid-low RC who underwent ME.

Functional linkage between N acquisition strategies and aeration capacities of hydrophytes for efficient oxygen consumption in roots.

We evaluated the specific strategies of hydrophytes for root O(2) consumption in relation to N acquisition and investigated whether the strategies varied depending on the aeration capacity. Aeration capacity of roots is an important factor for determining hypoxia tolerance in plants. However, some hydrophytes possessing quite different aeration capacities often co-occur in wetlands, suggesting that root O(2) consumption also strongly affects hypoxia tolerance. We cultivated Phragmites australis with high aeration capacity and Zizania latifolia with low aeration capacity in hypoxic conditions with NH(4)(+) or NO(3)(-) treatment and compared the growth, N uptake, N assimilation and root respiration between the two species. In Z. latifolia grown with NH(4)(+) treatment, high N uptake activity and restrained root growth led to sufficient N acquisition and decrease in whole-root respiration rate. These characteristics consequently compensated for the low aeration capacity. In contrast, in P. australis, low N uptake activity was compensated by active root growth, but the whole-root respiration rate was high. This high root respiration rate was allowed by the high aeration capacity. The O(2) consumption-related traits of hydrophyte roots were closely correlated with N acquisition strategies, which consequently led to a compensational relationship with the root aeration capacity. It is likely that this functional linkage plays an important role as a core mechanism in the adaptation of plants to hypoxic soils.

Tissue concentrations of antibiotics given prophylactically during colorectal cancer surgery.

BACKGROUND/AIMS: This study was designed to clarify the pharmacokinetics of prophylactically administered cefmetazole in serum, intestinal tissue, and subcutaneous adipose tissue in patients who underwent surgery for colorectal cancer. METHODOLOGY: Cefmetazole sodium (1 g) was given intravenously during the induction of anesthesia, followed by a 1-g dose after 3 hours. Blood samples were taken at the start of surgery, immediately before administration of the additional dose of cefmetazole, at the time of lesion resection, and at the time of wound closure. Tissue samples were obtained immediately after lesion resection and at the time of wound closure. Concentrations of cefmetazole in serum and tissue were measured by high performance liquid chromatography using an internal standard for calibration. Minimum inhibitory concentrations (MIC80) of cefmetazole for Escherichia coli, Klebsiella pneumoniae, and Bacteroides fragilis were measured, and pharmacokinetics were evaluated. RESULTS: In subcutaneous adipose tissue, cefmetazole concentrations were maintained higher than the MIC80's for E. coli and K. pneumoniae, but were low in all patients regardless of the time of measurement. CONCLUSIONS: The low transition rate of cefmetazole into subcutaneous adipose tissue indicates the need for additional measures, such as high-pressure washing of the subcutaneous wound tissue.

Laparoscopic surgery for obese patients with colon cancer: a case-matched control study.

PURPOSE: This study compared the results of laparoscopic surgery for colon cancer in obese patients with a body-mass index (BMI) of 25 kg/m(2) or higher with those in nonobese patients (BMI <25 kg/m(2)) who were matched for clinicohistopathological factors. METHODS: The oncologic outcomes were compared between 140 patients with a BMI of 25 kg/m(2) or higher (obese group) and 140 patients with a BMI of <25 kg/m(2) (nonobese group) that were matched for sex, tumor location, date of operation, and pTNM stage. RESULTS: The proportion of patients with postoperative complications was significantly higher in the obese group (15 %) than in the nonobese group (6 %). The disease-free survival rate and overall survival rate in patients with stage I or II disease were similar in the obese group (98.6 and 98.8 %, respectively) and the nonobese group (97.8 and 97.8 %, respectively). The disease-free survival rate and overall survival rate in patients with stage III disease also did not differ significantly between the obese group (77.2 and 79.4 %, respectively) and the nonobese group (83.4 and 84.9 %, respectively). CONCLUSIONS: Postoperative complications and long-term oncologic outcomes were similar in obese and nonobese patients who underwent laparoscopic colectomy for colon cancer in this hospital.