Effect of the lymphocyte-to-monocyte ratio on the prognosis of patients with obstructive colorectal cancer with a colonic stent: a retrospective multicenter study in Japan.

PURPOSE: The prognostic value of the lymphocyte-to-monocyte (LMR) ratio has been reported for various cancers, including colorectal cancer (CRC). The insertion of colonic stents is considered effective for patients with surgically indicated obstructive CRC, but their LMR can vary depending on factors such as inflammation associated with stent dilation and improvement of obstructive colitis. However, the usefulness of the LMR in patients with obstructive CRC and colonic stents and the optimal timing for its measurement remain unclear. We conducted this study to investigate the relationship between the pre-stent LMR and the mid-term prognosis of patients with obstructive CRC and stents as a bridge to surgery (BTS). METHODS: The subjects of this retrospective multicenter study were 175 patients with pathological stage 2 or 3 CRC. Patients were divided into a low pre-stent LMR group (n = 87) and a high pre-stent LMR group (n = 83). RESULTS: Only 3-year relapse-free survival differed significantly between the low and high pre-stent LMR groups (39.9% vs. 63.6%, respectively; p = 0.015). The pre-stent LMR represented a prognostic factor for relapse-free survival in multivariate analyses (hazard ratio 2.052, 95% confidence interval 1.242-3.389; p = 0.005), but not for overall survival. CONCLUSIONS: A low pre-stent LMR is a prognostic factor for postoperative recurrence in patients with obstructive CRC and a colonic stent as a BTS.

Risk factors for pulmonary complications after colorectal cancer surgery: a Japanese multicenter study.

PURPOSE: Pulmonary complications (PC) are a serious condition with a 20% mortality rate. However, few reports have examined risk factors for PC after colorectal surgery. This study investigated the frequency, characteristics, and risk factors for PC after colorectal cancer surgery. METHODS: Between January 2016 and December 2022, we retrospectively reviewed 3979 consecutive patients who underwent colorectal cancer surgery in seven participating hospitals. Patients were divided into patients who experienced PC (PC group, n = 54) and patients who did not (non-PC group, n = 3925). Clinical and pathological features were compared between groups. RESULTS: Fifty-four patients (1.5%) developed PC, of whom 2 patients (3.7%) died due to PC. Age was greater (80 years vs 71 years; p < 0.001), frequency of chronic obstructive pulmonary distress was greater (9.3% vs 3.2%; p = 0.029), performance status was poorer (p < 0.001), the proportion of underweight was higher (42.6% vs 13.4%, p < 0.001), frequency of open surgery was greater (24.1% vs 9.3%; p < 0.001), and blood loss was greater (40 mL vs 22 mL; p < 0.001) in the PC group. Multivariate analysis revealed male sex (odds ratio (OR) 2.165, 95% confidence interval (CI) 1.176-3.986; p = 0.013), greater age (OR 3.180, 95%CI 1.798-5.624; p < 0.001), underweight (OR 3.961, 95%CI 2.210-7.100; p < 0.001), and poorer ASA-PS (OR 3.828, 95%CI 2.144-6.834; p < 0.001) as independent predictors of PC. CONCLUSION: Our study revealed male sex, greater age, underweight, and poorer ASA-PS as factors associated with development of PC, and suggested that pre- and postoperative rehabilitation and pneumonia control measures should be implemented for patients at high risk of PC.

Monte carlo simulation study on the dose and dose-averaged linear energy transfer distributions in carbon ion radiotherapy.

Dose-averaged linear energy transfer (LETd) is conventionally evaluated from the relative biological effectiveness (RBE)-LETd fitted function used in the treatment planning system. In this study, we calculated the physical doses and their linear energy transfer (LET) distributions for patterns of typical CIRT beams using Monte Carlo (MC) simulation. The LETd was then deduced from the MC simulation and compared with that obtained from the conventional method. The two types of LETd agreed well with each other, except around the distal end of the spread-out Bragg peak. Furthermore, an MC simulation was conducted with the material composition of water and realistic materials. The profiles of physical dose and LETd were in good agreement for both techniques. These results indicate that the previous studies to analyze the minimum LETd in CIRT cases are valid for practical situations, and the material composition conversion to water little affects the dose distribution in the irradiation field.

Short- and Long-term Outcomes After Colonic Stent Insertion as a Bridge to Surgery in Elderly Colorectal Cancer Patients.

BACKGROUND/AIM: Colonic stents have been inserted as a bridge to surgery in patients with resectable colorectal cancer, allowing bowel decompression for systemic assessment and better preparation to avoid stoma construction. However, reports of short- and long-term prognoses for elderly patients remain limited. PATIENTS AND METHODS: This retrospective study reviewed 175 consecutive patients who underwent colonic stent insertion for bowel obstruction followed by curative colectomy. Patients were divided into those >80 years old (Old, n=49) and those <80 years old (Young, n=126). After propensity score matching, 41 patients in each group matched. RESULTS: Before matching, performance status was poorer (p<0.001), postoperative complication rate was higher (p=0.009), adjuvant chemotherapy rate was lower (p<0.001), and hospital stay was longer (p<0.001) in the Old group. After matching, adjuvant chemotherapy rate was lower (9.8% vs. 39.0%; p=0.003) and hospital stay was longer (14 vs. 12 days; p=0.029) in the Old group. Five-year relapse-free survival (42.9% vs. 68.8%; p=0.200), overall survival (66.3% vs. 87.7%; p=0.081), and cancer-specific survival (68.2% vs. 87.7%; p=0.129) rates were comparable between groups. CONCLUSION: Colorectal resection after colonic stent insertion is useful for elderly patients, with potential to reduce postoperative complication rates and achieve good long-term results with appropriate case selection.

Impact of institutional volume on short- and long-term outcomes after laparoscopic colectomy.

INTRODUCTION: The impact of institutional volume on postoperative outcomes after laparoscopic colectomy is still being debated. This study aimed to investigate whether differences in postoperative outcomes of laparoscopic colon resection exist between high- and low-volume centers. METHODS: Data were reviewed for 1360 patients who underwent laparoscopic colectomy for colon cancer between 2016 and 2022. Patients were divided according to whether they were treated at a high-volume center (≥100 colorectal surgeries annually; n = 947) or a low-volume center (<100 colorectal surgeries annually; n = 413). Propensity score matching was applied to balance covariates and minimize selection biases that could affect outcomes. Finally, 406 patients from each group were matched. RESULTS: After matching, patients from high-volume centers showed a higher number of retrieved lymph nodes (19 vs. 17, p < .001) and more frequent involvement of expert surgeons (98.3% vs. 88.4%, p < .001). Postoperative complication rates were similar between groups (p = .488). No significant differences between high- and low-volume centers were seen in relapse-free survival (88.8% each, p = .716) or overall survival (85.7% vs. 82.8%, p = .480). CONCLUSION: The present study suggests that in appropriately educated organizations, relatively safe procedures and good prognosis may be obtained for laparoscopic colectomy cases, regardless of institutional volume.

A case of pancreaticoduodenal artery bleeding after laparoscopic right colectomy requiring open hemostasis.

BACKGROUND: Pancreatic and duodenal-related complications after right colectomy carry a higher risk of mortality. CASE PRESENTATION: A 64-year-old woman underwent laparoscopic right colectomy for a laterally spreading tumor in the cecum. On postoperative day 10, she experienced sudden hematemesis. Contrast-enhanced computed tomography (CT) of the abdomen showed a large amount of hemorrhage in the stomach, but no obvious extravasation. In addition, free air was observed near the duodenal bulb. Despite blood transfusion, vital signs remained unstable and emergency surgery was performed. The abdomen was opened through midline incisions in the upper and lower abdomen. A fragile wall and perforation were observed at the border of the left side of the duodenal bulb and pancreas, with active bleeding observed from inside. As visualization of the bleeding point proved difficult, the duodenum was divided circumferentially to confirm the bleeding point and hemostasis was performed using 4-0 PDS. The left posterior wall of the duodenum was missing, exposing the pancreatic head. For reconstruction, the jejunum was elevated via the posterior colonic route and the duodenal segment and elevated jejunum were anastomosed in an end-to-side manner. Subsequently, gastrojejunal and Brown anastomoses were added. Drains were placed before and after the duodenojejunal anastomosis. Postoperative vital signs were stable and the patient was extubated on postoperative day 1. Follow-up contrast-enhanced CT of the abdomen showed no active bleeding, and the patient was discharged home on postoperative day 21. As of 6 months postoperatively, the course of recovery has been uneventful. CONCLUSIONS: We encountered a case of pancreaticoduodenal artery hemorrhage after laparoscopic right colectomy. Bleeding at this site can prove fatal, so treatment plans should be formulated according to the urgency of the situation.

Intestinal Behçet's and suspected intestinal Behçet's disease: a report of four surgical cases.

BACKGROUND: Intestinal Behçet's disease (BD) is often associated with ulceration that requires surgery, including perforation and abscess formation. However, no consensus has been reached on the optimal extent of resection or treatment strategy. This study reviewed four cases of intestinal or suspected intestinal BD. CASE PRESENTATIONS: In Case 1, a 74-year-old woman diagnosed with BD 2 years earlier was treated with anti-tumor necrosis factor α antibody (Infliximab) and steroids. She had oral and pubic ulcers. After close investigation of abdominal pain, perforation of the gastrointestinal tract was suspected and surgery was performed. Multiple perforating ulcers and abscesses were found in the distal ileum, and the small intestine was resected. Postoperatively, the patient was treated with an increased steroid dose and symptoms have remained stable. Case 2 involved a 69-year-old woman with oral and pubic ulcers, ocular ulcer, and skin lesions. She experienced sudden onset of abdominal pain during treatment for lymphoma. She showed multiple perforating ulcers throughout the ileum and underwent resection of the small intestine and ileostomy. Upper abdominal pain appeared during postoperative treatment for high-output syndrome. The patient underwent omentoplasty after perforation of the upper gastrointestinal tract was diagnosed. Postoperatively, anti-interleukin-1 beta antibodies (canakinumab) was administered to control the disease. Case 3 involved an 81-year-old, previously healthy woman. She presented to her previous physician with complaints of pubic ulcer, hemorrhage and abdominal pain. Colonoscopy showed multiple ulcers throughout the entire colon. Steroid therapy was started, but bleeding proved difficult to control and total proctocolectomy was performed. Histopathology revealed multiple perforating ulcers and BD was diagnosed. Postoperatively, the patient remains under steroid control. Case 4 involved a 43-year-old man with abdominal pain who showed abscess formation in the ileocecal region. After excision of the ileocecal area, multiple ulcers were diagnosed. Two years later, abdominal pain recurred and free air was found in the abdomen on close imaging. Emergency anastomotic resection was performed due to ulceration and perforation of the anastomosis. CONCLUSIONS: Intestinal BD may flare up after surgical treatment and require multiple surgeries. Introducing pharmacotherapy as soon as possible after surgical treatment is important to control the disease.

Correlations of age with clinicopathological features, perioperative outcomes and the prognosis in patients with colorectal cancer: a Japanese multicenter study.

PURPOSE: Colorectal cancer is not common in patients under 40 years old, and its associations with clinical features and the prognosis remain uncertain. METHODS: Using a multicenter database, we retrospectively reviewed 3015 patients who underwent colorectal surgery between 2016 and 2021. Patients were divided by age into those < 40 years old (young; n = 52), 40-54 years old (middle-aged; n = 254) and > 54 years old (old; n = 2709). We then investigated age-related differences in clinicopathological features, perioperative outcomes and the prognosis. RESULTS: The proportion of young patients increased annually from 0.63% in 2016 to 2.10% in 2021. Female patients were more frequent, the performance status was better, tumors were larger, clinically node-positive and poorly differentiated adenocarcinomas were more frequent, postoperative complications were less frequent, and the hospital stay was shorter in young patients than in older patients. Young age was an independent predictor of a low risk of postoperative complications (odds ratio, 0.204; 95% confidence interval, 0.049-0.849; p = 0.028). With pathologically node-positive status, adjuvant chemotherapy was more frequent in young patients (100%) than in middle-aged (73.7%) or old (51.8%) patients (p < 0.001), and the 3-year relapse-free survival was better in the young group than in others. CONCLUSION: Despite higher rates of advanced tumors in younger patients, adequate adjuvant chemotherapy appears to improve the relapse-free survival.

Risk factors for reoperation within 30 days in laparoscopic colorectal cancer surgery: A Japanese multicenter study.

INTRODUCTION: Thirty-day reoperation rate reflects short-term surgical outcomes following surgery. Laparoscopic surgery for colorectal cancer reportedly has positive effects on postoperative complications. This retrospective study investigated risk factors for 30-day reoperation rate among patients after laparoscopic colorectal cancer surgery using a multicenter database. METHODS: Participants comprised 3037 patients who had undergone laparoscopic resection of colorectal cancer between April 2016 and December 2022 at the Nagasaki University and six affiliated centers, classified into those who had undergone reoperation within 30 days after surgery (RO group; n = 88) and those who had not (NRO group; n = 2949). Clinicopathological characteristics were compared between groups. RESULTS: In the RO group, anastomotic leakage occurred in 57 patients (64.8%), intestinal obstruction in 12 (13.6%), and intraabdominal abscess in 5 (5.7%). Female patients were more frequent, preoperative treatment less frequent, body mass index (BMI) lower, operation time longer, blood loss greater, and hospital stay longer in the RO group (p < .05 each). Multivariate analysis revealed BMI (odds ratio, 0.415; 95% confidence interval, 0.218-0.787; p = .021) and poor performance status (odds ratio, 1.966; 95% confidence interval, 1.106-3.492; p = .021) as independent predictors of reoperation. CONCLUSION: Perioperative measures are warranted for patients with low BMI and poor performance status undergoing laparoscopic colorectal surgery.

Long-term outcomes and early recurrence after resection for metachronous pulmonary metastases from colorectal cancer.

PURPOSE: Properly selecting patients for aggressive curative resection for pulmonary metastases (PMs) from colorectal cancer (CRC) is desirable. We purposed to clarify prognostic factors and risk factors for early recurrence after metachronous PM resection. METHODS: Clinical data of 151 patients who underwent R0 resection for metachronous PMs from CRC at two institutions between 2008 and 2021 were reviewed. RESULTS: Seventy-six patients (50.3%) were male, and the median age was 71 (42-91) years. The numbers of colon/rectal cancers were 76/75, with pStage I/II/III/IV/unknown in 15/34/86/13/3. The duration from primary surgery to PM was 19.7 (1.0-106.4) months. The follow-up period was 41.9 (0.3-156.2) months. The 1-, 3-, and 5-year recurrence-free survival (RFS) rates were 75.1%, 53.7%, and 51.1%, and the 1-, 3-, and 5-year overall survival (OS) rates were 97.7%, 87.5%, and 68.2%. On multivariate analysis, lymph node metastasis of the primary lesion (HR 1.683, 95%CI 1.003-2.824, p = 0.049) was an independent predictor of poor RFS, and history of resection for extrapulmonary metastasis (e-PM) (HR 2.328, 95%CI 1.139-4.761, p = 0.021) was an independent predictor of poor OS. Patients who experienced early recurrence (< 6 months) after PM resection showed poorer OS than others (3-year OS 50.8% vs. 90.2%, p = 0.002). On multivariate analysis, e-PM was an independent predictor of early recurrence after PM resection (OR 3.989, 95%CI 1.002-15.885, p = 0.049). CONCLUSION: Since a history of e-PM was a predictor of early recurrence and poor OS after R0 resection for PM, surgical treatment of patients with a history of e-PM should be considered carefully.

Malignant peripheral nerve sheath tumor in the pelvis: a case report.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) are malignancies that arise or differentiate from or infiltrate peripheral nerves and account for approximately 5% of soft-tissue malignancies. Approximately half of MPNSTs develop in patients with neurofibromatosis type 1 (NF1), a hereditary disease. MPNSTs occur mainly in the trunk, proximal extremities, and neck, but can on rare occasion arise in or near the gastrointestinal tract, and intestinal complications have been reported. We describe herein a case with resection of an MPNST arising in the pelvic region. CASE PRESENTATION: A 51-year-old woman had undergone repeated resections for systemic neurofibrosis associated with NF1. This time, a pelvic tumor was noted on follow-up positron emission tomography computed tomography (CT). She presented with slowly progressive radiating pain in the lower extremities and was referred to our hospital for tumor resection. Contrast-enhanced CT showed a 75 × 58-mm mass in the right greater sciatic foramen directly below a 24 × 28-mm mass. Open pelvic tumor resection was performed for pelvic neurofibroma. The obturator nerve was identified lateral to the main tumor and the sciatic nerve was identified dorsally, then dissection was performed. The closed nerve was spared, while the sciatic nerve was partially dissected and the two tumors were removed. Both tumors were elastic and hard. Pathologic findings were MPNST for the large specimen and neurofibroma with atypia for the small specimen. The patient developed temporary postoperative ileus, but is generally doing well and is currently free of recurrence or radiating pain. The patient is at high risk of recurrence and close monitoring should be continued. CONCLUSIONS: We encountered a rare case of MPNST. Due to the high risk of recurrence, surgery with adequate margins was performed, with a requirement for appropriate follow-up.

A novel ex vivo lung cancer model based on bioengineered rat lungs.

Introduction: Two-dimensional cell cultures have contributed substantially to lung cancer research, but 3D cultures are gaining attention as a new, more efficient, and effective research model. A model reproducing the 3D characteristics and tumor microenvironment of the lungs in vivo, including the co-existence of healthy alveolar cells with lung cancer cells, is ideal. Here, we describe the creation of a successful ex vivo lung cancer model based on bioengineered lungs formed by decellularization and recellularization. Methods: Human cancer cells were directly implanted into a bioengineered rat lung, which was created with a decellularized rat lung scaffold reseeded with epithelial cells, endothelial cells and adipose-derived stem cells. Four human lung cancer cell lines (A549, PC-9, H1299, and PC-6) were applied to demonstrate forming cancer nodules on recellularized lungs and histopathological assessment were made among these models. MUC-1 expression analysis, RNA-seq analysis and drug response test were performed to demonstrate the superiority of this cancer model. Results: The morphology and MUC-1 expression of the model were like those of lung cancer in vivo. RNA sequencing revealed an elevated expression of genes related to epithelial-mesenchymal transition, hypoxia, and TNF-α signaling via NF-κB; but suppression of cell cycle-related genes including E2F. Drug response assays showed that gefitinib suppressed PC-9 cell proliferation equally well in the 3D lung cancer model as in 2D culture dishes, albeit over a smaller volume of cells, suggesting that fluctuations in gefitinib resistance genes such as JUN may affect drug sensitivity. Conclusions: A novel ex vivo lung cancer model was closely reproduced the 3D structure and microenvironment of the actual lungs, highlighting its possible use as a platform for lung cancer research and pathophysiological studies.

Association between the atrial tachyarrhythmia recurrence period and long-term major adverse clinical events following catheter ablation for atrial fibrillation.

Background: We previously demonstrated the clinical events in patients who underwent catheter ablation (CA) for atrial fibrillation (AF). Data on the association between the period of atrial tachyarrhythmia (ATA) recurrence after CA and long-term major adverse clinical events (MACE) remain unclear. In this study, we evaluated this issue in patients with systolic impairment (left ventricular ejection fraction < 50%) and heart failure with preserved ejection fraction (HFpEF). Methods: We retrospectively collected data from 81 patients with systolic impairment and 83 patients with HFpEF who underwent CA for AF at our institution (median follow-up: 4.9 [3.6, 6.6] years). In each group, we compared the cumulative incidence of long-term MACE (since 1 year after CA) between patients with and without ATA recurrence at three follow-up periods (3, 6 months, and 1 year after index CA). We evaluated the period of recurrence, which was the most beneficial predictor of MACE among the periods. Results: In the systolic impairment group, the cumulative long-term MACE incidence was significantly higher in patients with ATA recurrence than in those without it within 6 months and 1 year (P = 0.04 and P = 0.01, respectively). Recurrence within 1 year showed the highest feasibility for predicting long-term MACE (area under the curve with 95% confidence interval [CI]:0.73 [0.61-0.84]). However, there was no difference in the incidence of MACE between patients with and without recurrence in a group with HFpEF in each period. Conclusion: ATA recurrence within 1 year could predict long-term MACE in patients with systolic impairment, but not in patients with HFpEF.

Impacts of trans-anal tube placement in patients with sigmoid colon cancer: Risk verification analysis using inverse probability weighting analysis.

Purpose: Anastomotic leakage (AL) is a serious postoperative complication that affects short- and long-term outcomes. The use of a trans-anal drainage tube (TDT) is reported to prevent AL in rectal cancer patients, but its value in sigmoid colon cancer patients is unknown. Methods: Admitted to the study were 379 patients who underwent surgery for sigmoid colon cancer between 2016 and 2020. Patients were divided into two groups according to the placement (n = 197) or nonplacement of a TDT (n = 182). To determine the factors affecting the association between TDT placement and AL, we estimated average treatment effects by stratifying each factor using the inverse probability of treatment weighting method. The association between prognosis and AL was evaluated in each identified factor. Results: Factors associated with postsurgical insertion of a TDT were advanced age, male sex, high body mass index (BMI), poor performance status, and presence of comorbidities. TDT placement was associated with a significantly lower AL in male patients (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.07-0.73; P = .013) and for BMI ≥ 25 kg/m2 (OR, 0.13; 95% CI, 0.02-0.65; P = .013). In addition, there was a significant association of AL with poor prognosis in patients with BMI ≥ 25 kg/m2 (P = .043), age > 75 y (P = .021), and pathological node-positive disease (P = .015). Conclusion: Sigmoid colon cancer patients with BMI ≥ 25 kg/m2 are the most appropriate candidates for postoperative TDT insertion, in terms of reduced incidence of AL and improved prognosis.

Mid-term outcomes of laparoscopic vs open colectomy for pathological T4 and/or N2 colon cancer patients: Multicenter study using propensity score matched analysis.

OBJECTIVES: We aimed to assess mid-term outcomes after laparoscopic surgery (LAP) vs open surgery (OP) for pathological T4 (pT4) and/or N2 (pN2) colon cancer. METHODS: We retrospectively reviewed 255 primary tumor resections for pT4 and/or pN2 colon cancer performed from 2015 to 2020 at six hospitals, divided into LAP (n = 204) and OP groups (n = 51). After propensity score matching to minimize selection bias, 47 matched patients per group were assessed. RESULTS: Before matching, the rate of males (53.9% vs. 37.3%, P = .042), left sided colon cancer (53.9% vs 37.3%, P = .042), D3 lymph node dissection (90.7% vs 68.6%, P < .001) and body mass index (kg/m2 ) (22.3 vs 21.8, P = .039) were significantly greater in the LAP group. The rate of pT4b (7.8% vs 40.4%, P < .001) was lower and pN2 was higher (57.4% vs 37.3%, P = .012) in the LAP group. After matching, preoperative characteristics and pathologic status were equivalent between the groups. The LAP and OP groups showed comparable overall survival (OS) (2-year OS, 84.5% vs 76.8%, P = .055) and recurrence-free survival (RFS) (2-year RFS, 73.9% vs 52.8%, P = .359). In the patients with pT4, OS (2-year OS, 79.4% vs 75.7%, P = .359) and RFS (2-year RFS, 71.3% vs 58.7%) were comparable. In the patients with pN2, OS (2-year OS, 83.4% vs 76.3%) and RFS (2-year RFS, 69.6% vs 36.2%) were also comparable. CONCLUSIONS: LAP for pT4 and/or pN2 colon cancer showed comparable mid-term outcomes compared with OP. LAP was an acceptable surgical approach in this cohort.

Efficacy of Neutrophil-to-Lymphocyte Ratio for Cancer-Specific Survival in Elderly Patients with Localized Colon Cancer: A Single Center Propensity Score-Matched Analysis.

Purpose: The prognostic value of neutrophil-to-lymphocyte ratio (NLR) has been studied for colorectal cancer. Elderly patients in general tend to have comorbidities and decreased organ function that potentially influence the NLR score. The aim of this study was to investigate the relationship between NLR and cancer-specific survival in elderly patients with colon cancer, using a propensity score-matched analysis. Patients and Methods: A total of 203 patients aged over 75 years who underwent curative resection for colon cancer and were diagnosed pathologically with stage II/III disease were eligible for entry to the study. Patients were divided into two groups according to NLR score: NLR-High (NLR≥4.5) group (NLR-H, n=60) and NLR-Low (NLR<4.5) group (NLR-L, n=143). After propensity score matching, 57 patients in each group were matched. Results: Before matching, Charlson comorbidity index was significantly higher in the NLR-H group (4 vs 2, p<0.001). After matching, all factors were similar between the groups. The median follow-up period was 43 months (range, 1-160 months). Five-year relapse-free-survival (69.8% vs 87.3%, p=0.030) and cancer-specific survival (83.0% vs 96.0%, p=0.042) were significantly lower in the NLR-H group. Conclusion: NLR appears to be a cancer-specific prognostic marker in elderly patients with colon cancer.

Gustave Roussy Immune Score for Predicting Postoperative Complications and Non-cancer Death in Elderly Patients With Colon Cancer.

BACKGROUND/AIM: The Gustave Roussy Immune (GRIm) score is aa prognostic marker in various cancer types. The aim of this study was to investigate the relationship between the GRIm score and short- and long-term outcomes in elderly patients with colon cancer. PATIENTS AND METHODS: Patients aged ≥75 years who underwent colectomy between 2008 and 2019 were eligible for the study. Patients were divided into high GRIm (score 1-3) and low GRIm (score 0) groups. RESULTS: A total of 430 patients were enrolled (high GRIm, n=126; low GRIm, n=304). A high GRIm score was an independent predictive factor for postoperative complications [odds ratio=4.146; 95% confidence interval (CI)-2.536-6.777; p<0.001]. The median follow-up was 42 months (range=1-160 months). Five-year relapse-free (79.3% vs. 92.7%; p=0.001), overall (76.0% vs. 92.2%, p=0.001), and non-cancer-specific (84.7% vs. 94.6%, p=0.003) survival were lower in the high GRIm group. Multivariate analysis revealed a high GRIm score to be an independent predictive factor for poorer overall (hazard ratio=2.875; 95% CI=1.451-5.698; p=0.002) and non-cancer-specific (hazard ratio=3.650; 95% CI=1.612-8.265; p=0.001) survival. CONCLUSION: The GRIm score is useful for predicting postoperative complications and non-cancer cause of death in elderly patients and might be suitable as a surrogate marker for selecting candidates for surgery or perioperative treatment.

Development of the DICOM-based Monte Carlo dose reconstruction system for a retrospective study on the secondary cancer risk in carbon ion radiotherapy.

Objective.A retrospective study on secondary cancer risk on carbon ion radiotherapy (CIRT) is ongoing at the Heavy Ion Medical Accelerator in Chiba (HIMAC). The reconstruction of the whole-body patient dose distribution is the key issue in the study because dose distribution only around the planning target volume was evaluated in the treatment planning system.Approach.We therefore developed a new dose reconstruction system based on the Particle and Heavy Ion Transport code System (PHITS) coupled with the treatment plan DICOM data set by extending the functionalities of RadioTherapy package based on PHITS (RT-PHITS). In the system, the geometry of patient-specific beam devices such as the range shifter, range compensator, and collimators as well as the individual patient's body are automatically reconstructed. Various functions useful for retrospective analysis on the CIRT are implemented in the system, such as those for separately deducing dose contributions from different secondary particles and their origins.Main results.The accuracy of the developed system was validated by comparing the dose distribution to the experimental data measured in a water tank and using a treatment plan on an anthropomorphic phantom.Significance.The extended RT-PHITS will be used in epidemiological studies based on clinical data from HIMAC.

Total Risk Points Predict Short- and Long-term Outcomes Following Colorectal Cancer Resection in Older Patients.

BACKGROUND/AIM: Estimation of physiological ability and surgical stress (E-PASS) is reported to be useful as a predictor of postoperative complications and poor long-term survival after colorectal cancer. The total risk points (TRP) system is a simplified scoring system of E-PASS, and this study evaluated the utility of TRP in colorectal cancer resection in older patients. PATIENTS AND METHODS: The clinicopathological data of 237 patients who underwent curative resection for colorectal cancer from 2015 to 2020 were analyzed retrospectively. The data were compared between a high TRP group (≥1,000, n=38) and a low TRP group (<1,000, n=199). We also conducted an analysis to determine risk factors of postoperative complications and poor long-term survival. RESULTS: TRP showed statistically significant correlations with the comprehensive risk score (CRS) of E-PASS (R=0.999, p<0.001). The high TRP group experienced postoperative complications (Clavien-Dindo grade ≥2) more frequently (42.1% vs. 11.1%, p<0.001). Multivariate analysis showed that high TRP [odds ratio (OR)=5.214; 95% confidence interval (95%CI)=2.338-11.629; p<0.001] and age ≥80 (OR=2.760; 95%CI=1.308-5.826; p=0.008) were independent predictors of postoperative complications. Overall survival (OS) was poor in the high TRP group (5-year OS, 61.2% vs. 82.6%, p<0.001) compared with the low TRP group, and in the low prognostic nutritional index (<45) group (5-year OS, 70.9% vs. 86.3%, p=0.013) compared with the high prognostic nutritional index (≥45) group. Multivariate analysis showed that high TRP [hazard ratio (HR)=3.202; 95%CI=1.324-7,745; p=0.010] was an independent prognostic factor for poor OS. CONCLUSION: Patients aged ≥80 years should be closely monitored regarding postoperative complications. Reducing TRP to less than 1,000 is important to reduce postoperative complications and improve OS.

Utility of Drain Fluid Culture and Gram Stain in Early Intervention for Occult Anastomotic Leakage in Colorectal Cancer.

BACKGROUND/AIM: Although occult leakage after colorectal surgery does not usually cause critical illness, it can cause long-term complications that decrease the quality of life of patients. There is currently no established diagnostic, treatment, or follow-up method for occult leakage. We assessed the risk factors of occult leakage and examined the efficacy of drain fluid culture and Gram staining for its early detection and appropriate treatment intervention. PATIENTS AND METHODS: Data from 243 consecutive colorectal cancer patients who underwent resection with reconstruction by the double stapling technique between 2016 and 2020 were reviewed. RESULTS: Sixteen (6.6%) patients had postoperative occult leakage. Multivariate analysis revealed that preoperative treatment was significantly associated with occult leakage (odds ratio=12.423; 95% confidence interval=4.095 to 17.680; p<0.001). Among the 16 patients, 1 experienced stenosis, and none experienced a fistula or chronic sinus. Drain fluid samples of 34 patients (14.0%) were Gram stainpositive, and those of 76 patients (31.3%) were culturepositive. The positive and negative predictive values of drain fluid culture were 18.4% and 98.7%, respectively, and those of Gram staining were 38.2% and 98.6%, respectively, for occult leakage. Among cases with occult leakage, more than two bacterial species were detected in 71.5% of the cultures. Antibiograms indicated that the three major species tended to be resistant to cephem antibiotics, which are used for prophylaxis, but susceptible to carbapenem antibiotics, which are used for empiric therapy. CONCLUSION: Drain fluid culture and Gram staining may enable early detection and appropriate treatment intervention for occult leakage.