Multi-institutional Registry of Large Bowel Cancer in Japan Conducted by the Japanese Society for Cancer of the Colon and Rectum in 2023: Cases Treated in 2015.

Objectives: Colorectal cancer is the most prevalent malignant disease in Japan. This study aimed to publish data on colorectal cancer cases registered in 2023, involving initial treatments in 2015. Methods: Participating facilities of the Japanese Society for Cancer of the Colon and Rectum (JSCCR) registered cases treated in 2015 according to the 8th edition of the Japanese Classification of Colorectal Carcinoma. Data sent to the National Registration Committee in 2023 were analyzed. Results: The study analyzed 12,804 cases. Endoscopic treatments were performed in 983 cases, endoscopic treatment followed by surgical resection in 734 cases, and surgeries were carried out in 10,884 cases. Notably, the proportion of laparoscopic surgeries increased significantly from 34.7% in 2010 to 63.5% in 2015. Conclusions: This report details the characteristics, treatment methods, and outcomes of colorectal cancer patients who received initial treatment in 2015 at JSCCR-participating facilities. These data should be helpful for patients to understand their disease accurately and for healthcare professionals to explain colorectal cancer and its treatments to patients.

Sex differences in recovery from postoperative sarcopenia during adjuvant CAPOX therapy for colorectal cancer.

BACKGROUND: Women are predisposed to develop intolerance to cancer chemotherapy. Sarcopenia and chemotherapy are mutually related. Women are generally intolerable to chemotherapeutics such as 5-fluorouracil. Although adjuvant oxaliplatin-based chemotherapy, e.g. CAPOX is commonly used to treat colorectal cancer, its effects on patients in terms of sarcopenia and sex remain unknown. We investigated sex disparities in the impacts of CAPOX on body composition in this study. METHODS: We conducted a prospective study on diagnostic metrics used for sarcopenia in colorectal cancer patients receiving adjuvant CAPOX. Evaluations of the nutritional status by the Mini-Nutritional Assessment (MNA), gait speed, grip strength, skeletal muscle mass, fat mass, and bone mineral content using a body composition analyzer were performed in the first, fourth, and eighth cycles of CAPOX (first, second, and third measurements, respectively). RESULTS: Among 80 eligible patients, 61 completed four CAPOX cycles. The median differences in MNA, gait, grip strength, muscle mass, fat mass, and bone mineral content between the first and second measurements for men (n = 35) and women (n = 26) were + 10.5% and + 2.9% (p = 0.067), + 4.5% and - 2.6% (p = 0.16), + 1.8% and + 2.8% (p = 0.66), + 2.7% and + 1.3% (p = 0.021), + 4.5% and + 3.5% (p = 0.59), and + 3.3% and + 0.0% (p = 0.006), There were no sex differences in comparisons of the above metrics between the first and third measurements in 34 patients who completed eight CAPOX cycles (19 wen and 15 women). CONCLUSIONS: Early cycles of adjuvant CAPOX may have a negative impact on the postoperative recovery of several metrics for diagnosing sarcopenia in women.

Evaluation of the accuracy of automated segmentation based on deep learning for prostate cancer patients.

PURPOSE: This study evaluated the accuracy of a commercial deep learning (DL)-based algorithm for segmenting the prostate, seminal vesicles (SV), and organs at risk (OAR) in patients with prostate cancer. METHODS: Ten patients with prostate cancer were selected to compare automated and manual segmentation. The prostate, SV, and OAR, including the bladder, rectum, left and right femoral heads, and penile bulb, were delineated and reviewed according to our institutional protocols by radiation oncologists. The CT and MR images were fused to the prostate, and the prostate and penile bulb were manually delineated on the CT and MR images. The remaining organs were delineated on the CT images without the MR images. MVision AI Contour+ was used to perform DL-based automated segmentation. The dice similarity coefficient (DSC) and 95% Hausdorff distance (HD95%) were evaluated for comparison with manual delineations. RESULTS: The mean DSC values for the prostate, SV, bladder, rectum, both femoral heads, and penile bulb were 0.86, 0.80, 0.96, 0.92, 0.97, and 0.64, respectively. The HD95% for all the organs was less than 3 mm. CONCLUSIONS: The commercial DL-based auto segmentation solution provided high-quality contours in patients with prostate cancer.

Identification of lateral pelvic nodes without metastasis in patients with rectal cancer treated with preoperative chemoradiotherapy or chemotherapy based on magnetic resonance imaging.

Background: Intensive localized therapy is promising for the treatment of rectal cancer. In Japan, chemoradiotherapy (CRT) and neoadjuvant chemotherapy (NAC) are used as preoperative treatments for this disease. Magnetic resonance imaging (MRI) is used to diagnose lateral pelvic node (LPN) metastases, but the changes in LPN findings on MRI following preoperative treatment are unclear. Furthermore, there may be patients in whom LPN dissection can be omitted after CRT/NAC. Methods: Patients who underwent total mesorectal excision with LPN dissection after CRT/NAC at 13 Japanese Society for Cancer of the Colon and Rectum member institutions between 2017 and 2019 were included. Changes in the short diameter of the LPNs after CRT/NAC and the reduction rate were examined. Results: A total of 101 LPNs were examined in 28 patients who received CRT and 228 in 47 patients who received NAC. Comparison of LPNs before and after CRT/NAC showed that most LPNs shrank after CRT but that the size reduction was variable after NAC. Although some LPNs with a short diameter of <5 mm showed residual metastasis, no metastases were observed in LPNs that were <5 mm in short diameter before and after CRT/NAC and did not shrink after treatment. Conclusion: Although the short diameter of LPNs was significantly reduced by both CRT and NAC, even LPNs with a short diameter of <5 mm could have residual metastases. However, dissection may be omitted for LPNs <5 mm in short diameter that do not shrink after preoperative CRT or NAC.

Peritoneal lavage cytology in patients with curative resection for stage II and III colorectal cancer: A multi-institutional prospective study.

Aim: To clarify the usefulness of intraoperative lavage cytology in patients undergoing curative resection for pStage II-III colorectal cancer in a prospective multicenter study. Methods: Patients preoperatively diagnosed with stage II-III colorectal cancer between 2013 and 2017 from 20 hospitals were enrolled. Lavage cytology was performed twice during the surgery. The primary endpoint was the effect of lavage cytology on the 5-year relapse-free survival (RFS) in patients with pStage II-III colorectal cancer. The secondary endpoint was the effect of lavage cytology on the 5-year overall survival (OS) and peritoneal recurrence. Results: A total of 1378 patients were eligible for analysis. The number of patients with pStage II-III colorectal cancer was 670 and 708, respectively. Fifty-four patients (3.9%) had positive cytological results. In pStage II patients, the 5-year RFS rates with positive and negative cytology were 61.1% and 81.6%, respectively (p = 0.023). The 5-year OS rates were 67.1% and 91.7%, respectively (p = 0.0083). However, there was no difference in RFS or OS between pStage III patients with positive and negative cytology results. The peritoneal recurrence rates were 11.8% and 1.5% in pStage II patients with positive and negative cytology results, respectively (p = 0.032). These rates were 10.5% and 2.5% in patients with stage III disease, respectively (p = 0.022). Conclusion: Stage II colorectal cancer patients with negative cytology had better outcomes than those with positive cytology. Peritoneal lavage cytology is useful for predicting peritoneal recurrence after curative resection of stage II-III colorectal cancer.

Prognosis of early-onset vs. late-onset stage II/III colorectal cancer patients with adjuvant chemotherapy: a multicenter propensity score matched study.

BACKGROUND: Colorectal cancer (CRC) is a major global health concern, with a rising incidence in young individuals. Early-onset CRC displays unique clinicopathological and molecular characteristics, necessitating a closer examination of prognosis, particularly in the context of adjuvant chemotherapy. This study aimed to investigate the prognosis of early-onset CRC patients (< 50 years) diagnosed at stage II/III compared to older counterparts, utilizing propensity score matching to minimize heterogeneity. METHODS: A retrospective analysis of 3324 stage II/III CRC patients aged < 70 years was conducted, focusing on age-based subgroups (< 50 vs. ≥ 50 years). Propensity score matching balanced clinical characteristics. Relapse-free survival (RFS) and overall survival (OS) were analyzed. RESULTS: In stage II CRC, age of onset did not impact prognosis after adjuvant chemotherapy, with no significant differences in RFS (5-year RFS rates: 80% in both groups, p = 0.98) and OS (5-year OS rates: 96% vs. 92%, p = 0.17). In stage III, a trend suggested slightly poorer OS in patients aged < 50 years than those ≥ 50 years (5-year OS rates: 85% vs. 88%, p = 0.077). However, in a propensity score-matched cohort, age-dependent differences were attenuated (5-year OS rates: 85% vs. 88%, p = 0.32). CONCLUSION: In the context of stage II/III CRC patients receiving adjuvant chemotherapy, age was not an independent predictor of prognosis. Age alone should not be the sole factor guiding treatment decisions.

Possible poor prognosis in younger-onset Crohn's disease-associated anorectal cancer: A subanalysis of the Nationwide Japanese study.

Background and aims: Crohn's disease (CD)-associated intestinal cancers are characterized by their high incidence, particularly at the anorectal site in the Japanese population. Accumulating evidence revealed that younger-onset sporadic colorectal cancer may exhibit unique biological features. To the best of our knowledge, few previous articles reported clinicopathological features in patients with CD-associated anorectal cancer (CDAAC). Therefore, we aimed to clarify the relationship between the younger onset of cancer and clinicopathological characteristics and prognosis, and the efficacy of cancer surveillance in patients with CDAAC. Methods: CD patients who had been diagnosed with intestinal cancers from 1983 to 2020 were collected from 39 Japanese institutions in this study. Of 316 patients with CD-associated intestinal cancers, we analyzed 211 patients with CDAAC. We divided the patients into two groups according to the median age at cancer diagnosis (45 years old). Results: Younger-onset CDAAC (YO-CDAAC) patients were significantly more likely to have a poor outcome than those with older-onset CDAAC (OO-CDAAC) in terms of both disease-free survival (DFS) (p = 0.0014) and overall survival (OS) (p = 0.023). Multivariate analysis showed that age under 45 years old at diagnosis of cancer was one of the independent factors for poor DFS and OS (hazard ratios: 2.15, 95% confidence interval: 1.09-4.26, p = 0.028, hazard ratios: 1.95, 95% confidence interval: 1.05-3.60, p = 0.033, respectively). Patients detected via surveillance showed significantly better DFS and OS rates than symptomatic patients in YO-CDAAC (p = 0.012 and 0.0031, respectively). Conclusions: YO-CDAAC may have a poorer prognosis compared with OO-CDAAC. Surveillance could be important to improve cancer prognosis, especially in young CD patients with anorectal disease.

Indoleamine 2,3-Dioxygenase Inhibitor Suppresses Colon Cancer Cell Migration, Invasion, and Epithelial-Mesenchymal Transition.

BACKGROUND/AIM: Indoleamine 2,3-dioxygenase 1 (IDO1) is a key enzyme in tryptophan metabolism and plays an important role in immunosuppression. The effects of IDO1 on tumor invasion and metastasis have been studied in several types of malignancies. However, the role of IDO1 in these steps in colorectal cancer (CRC) has not been elucidated. Therefore, we aimed to investigate the effects of IDO1 on invasion, migration, and epithelial-mesenchymal transition (EMT) in CRC cells. MATERIALS AND METHODS: All experiments were performed using the DLD-1 colon cancer cell line that expresses IDO1. We conducted a scratch wound healing assay and Boyden chamber assay to investigate the impact of IDO1 on DLD-1 cell migration and invasion, respectively, in the presence and absence of the IDO1 inhibitor L-1-methyl-tryptophan (L-1-MT). Additionally, western blotting was performed to analyze alterations in the expression of EMT-related markers caused by L-1-MT. RESULTS: High expression of IDO1 was confirmed in the cytoplasm of DLD-1 by immunofluorescence staining. In the scratch wound healing assay, the invasion ability of DLD-1 cells decreased to 62% after treatment with L-1-MT at 1,000 µM for 24 h. In the Boyden chamber assay, the migration of DLD-1 cells was suppressed by 85% after treatment with L-1-MT at 2,500 µM for 24 h. L-1-MT treatment increased the expression level of E-cadherin and decreased the expression levels of vimentin, Snail, and Slug. CONCLUSION: IDO1 inhibition reduced the invasion and migration ability of IDO1-expressing DLD-1 colon cancer cells, which was accompanied by altered expression of EMT-related proteins. IDO1 could be a potential target for the treatment of advanced CRC.

Long-term Outcome After Surgical Resection of Para-aortic Lymph Node Metastasis of Colorectal Cancer: A Multicenter Retrospective Study.

BACKGROUND: The significance of resection of para-aortic lymph node metastasis in colorectal cancer is controversial. OBJECTIVE: To clarify the prognosis of colorectal cancer after para-aortic lymph node metastasis resection. DESIGN: Multicenter retrospective study. SETTINGS: Thirty-six institutions in Japan participated in this study. Database and medical records at each institution were used for data collection. PATIENTS: Patients with resected and pathologically proven para-aortic lymph node metastasis of colorectal cancer between 2010 and 2015 were included. MAIN OUTCOME MEASURES: Overall survival after para-aortic lymph node metastasis resection, recurrence-free survival, and recurrence patterns after R0 resection of para-aortic lymph node metastasis. RESULTS: A total of 133 patients were included in the primary analysis population in this study. The 5-year overall survival rate (95% CI) was 41.0% (32.0-49.8), and the median survival (95% CI) was 4.1 (3.4-4.7) years. Independent prognostic factors for overall survival were the pathological T stage (pT4 vs pT1- 3, adjusted HR: 1.91, p = 0.006), other organ metastasis (present vs absent, adjusted HR: 1.98, p = 0.005), time to metastases (synchronous vs metachronous adjusted HR: 2.02, p = 0.02), and the number of para-aortic lymph node metastasis (3 or more vs less than 3, adjusted HR: 2.13, p = 0.001). The 5-year recurrence-free survival rate (95% CI) was 21.1% (13.5-29.7), with a median (95% CI) of 1.2 (0.9-1.4) years. The primary tumor location (left- vs right-sided colon, adjusted HR: 4.77, p = 0.01; rectum vs right-sided colon, adjusted HR: 5.27, p = 0.006), other organ metastasis (present vs absent, adjusted HR: 1.90, p = 0.03), number of para-aortic lymph node metastases (3 or more vs less than 3, adjusted HR: 2.20, p = 0.001), and hospital volume (less than 10 vs 10 or more, adjusted HR: 2.18, p = 0.02) were identified as independent prognostic factors for recurrence-free survival. Para-aortic lymph node recurrence was the most common at 33.3%. LIMITATIONS: Selection bias cannot be ruled out because of the retrospective nature of the study. CONCLUSIONS: Less than 3 para-aortic lymph node metastases were a favorable prognostic factor for overall and recurrence-free survival. However, para-aortic lymph node metastases were considered to be a systemic disease, and the significance of resection was limited. See Video Abstract . RESULTADO A LARGO PLAZO POSTERIOR A LA RESECCIN QUIRRGICA DE METSTASIS EN GANGLIOS LINFTICOS PARAARTICOS DE CNCER COLORRECTAL UN ESTUDIO RETROSPECTIVO MULTICNTRICO: ANTECEDENTES:La importancia de la resección de metástasis en los ganglios linfáticos paraaórticos (PALNM) en el cáncer colorrectal (CCR) es controvertida.OBJETIVO:Aclarar el pronóstico del CCR después de la resección PALNM.DISEÑO:Estudio retrospectivo multicéntrico.ENTORNO CLINICO:Treinta y seis instituciones en Japón participaron en este estudio.PACIENTES:Pacientes con PALNM de CCR resecado y patológicamente probado entre 2010 y 2015.FUENTES DE DATOS:Base de datos y registros médicos de cada institución.PRINCIPALES MEDIDAS DE RESULTADO:Supervivencia general (SG) después de la resección PALNM, supervivencia libre de recurrencia (SLR) y patrones de recurrencia después de la resección R0 de PALNM.RESULTADOS:Se incluyó un total de 133 pacientes en la población de análisis primario de este estudio. La tasa de SG a 5 años (intervalo de confianza [IC] del 95 %) fue del 41,0 % (32,0, 49,8) y la mediana de supervivencia (IC del 95 %) fue de 4,1 (3,4, 4,7) años. Los factores de pronóstico independientes para la SG fueron el estadio T patológico (pT4 vs. pT1-3, índice de riesgo ajustado [aHR]: 1,91, p = 0,006), metástasis en otros órganos (presente vs. ausente, aHR: 1,98, p = 0,005), tiempo hasta las metástasis (síncronas vs. metacrónicas, aHR: 2,02, p = 0,02) y número de PALNM (≥3 vs. <3, aHR: 2,13, p = 0,001). La tasa de SLR a 5 años (IC del 95%) fue del 21,1% (13,5, 29,7), con una mediana (IC del 95%) de 1,2 (0,9, 1,4) años. La ubicación del tumor primario (colon del lado izquierdo vs. derecho, aHR: 4,77, p = 0,01; recto vs. colon del lado derecho, aHR: 5,27, p = 0,006), metástasis en otros órganos (presente vs. ausente, aHR: 1,90, p = 0,03), el número de PALNM (≥3 vs. <3, aHR: 2,20, p = 0,001) y el volumen hospitalario (<10 vs. ≥10, aHR: 2,18, p = 0,02) se identificaron como independientes factores pronósticos del SLR. La recurrencia de los ganglios linfáticos paraaórticos fue la más común con un 33,3%.LIMITACIONES:No se puede descartar un sesgo de selección debido a la naturaleza retrospectiva del estudio.CONCLUSIONES:Menos de tres PALNM fue un factor pronóstico favorable tanto para la SG como para la SLR. Sin embargo, las PALNM se consideraron una enfermedad sistémica y la importancia de la resección fue limitada. (Traducción- Dr. Francisco M. Abarca-Rendon ).

Endoscopic Artificial Intelligence for Image Analysis in Gastrointestinal Neoplasms.

BACKGROUND: Artificial intelligence (AI) using deep learning systems has recently been utilized in various medical fields. In the field of gastroenterology, AI is primarily implemented in image recognition and utilized in the realm of gastrointestinal (GI) endoscopy. In GI endoscopy, computer-aided detection/diagnosis (CAD) systems assist endoscopists in GI neoplasm detection or differentiation of cancerous or noncancerous lesions. Several AI systems for colorectal polyps have already been applied in colonoscopy clinical practices. In esophagogastroduodenoscopy, a few CAD systems for upper GI neoplasms have been launched in Asian countries. The usefulness of these CAD systems in GI endoscopy has been gradually elucidated. SUMMARY: In this review, we outline recent articles on several studies of endoscopic AI systems for GI neoplasms, focusing on esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), gastric cancer (GC), and colorectal polyps. In ESCC and EAC, computer-aided detection (CADe) systems were mainly developed, and a recent meta-analysis study showed sensitivities of 91.2% and 93.1% and specificities of 80% and 86.9%, respectively. In GC, a recent meta-analysis study on CADe systems demonstrated that their sensitivity and specificity were as high as 90%. A randomized controlled trial (RCT) also showed that the use of the CADe system reduced the miss rate. Regarding computer-aided diagnosis (CADx) systems for GC, although RCTs have not yet been conducted, most studies have demonstrated expert-level performance. In colorectal polyps, multiple RCTs have shown the usefulness of the CADe system for improving the polyp detection rate, and several CADx systems have been shown to have high accuracy in colorectal polyp differentiation. KEY MESSAGES: Most analyses of endoscopic AI systems suggested that their performance was better than that of nonexpert endoscopists and equivalent to that of expert endoscopists. Thus, endoscopic AI systems may be useful for reducing the risk of overlooking lesions and improving the diagnostic ability of endoscopists.

Robotic Versus Laparoscopic Abdominoperineal Resection for Locally Advanced Rectal Cancer Following Preoperative Chemoradiotherapy.

BACKGROUND/AIM: The usefulness of robotic surgery compared to laparoscopic surgery for rectal cancer has been reported; however, few reports exist on robotic abdominoperineal resection (APR). The aim of this study was to compare the outcomes of robotic and laparoscopic surgery to determine their usefulness in patients with locally advanced rectal cancer who had undergone preoperative chemoradiotherapy (CRT). PATIENTS AND METHODS: This retrospective study included 43 patients with locally advanced rectal cancer who underwent preoperative CRT and robotic (22 patients) or laparoscopic APR (21 patients) between December 2012 and September 2022. We examined the short- and long-term outcomes in the robotic and laparoscopic groups. RESULTS: The median follow-up durations were 36 and 48 months for the robotic and laparoscopic groups, respectively. No significant differences in operative time, intraoperative blood loss, or overall complication rates were observed. However, the incidence of organ/space surgical site infection (SSI) was significantly lower in the robotic surgery group than in the laparoscopic group (9.1% vs. 38.1%, p=0.034) and the 3-year overall survival rate was significantly higher in the robotic surgery group than in the laparoscopic group (95% vs. 67%, p=0.029). CONCLUSION: Robotic APR was associated with a significantly lower rate of organ/space SSIs than the laparoscopic approach, indicating the usefulness of the robotic approach.

Long-Term Outcomes of Additional Surgery After Endoscopic Resection Versus Primary Surgery for T1 Colorectal Cancer.

INTRODUCTION: There is considerable concern about whether endoscopic resection (ER) before additional surgery (AS) for T1 colorectal cancer (CRC) has oncologically potential adverse effects. Therefore, the aim of this study was to compare the long-term outcomes, including overall survival (OS), of patients treated with AS after ER vs primary surgery (PS) for T1 CRC using a propensity score-matched analysis from a large observational study. METHODS: This study investigated 6,105 patients with T1 CRC treated with either ER or surgical resection between 2009 and 2016 at 27 high-volume Japanese institutions, with those undergoing surgery alone included in the PS group and those undergoing AS after ER included in the AS group. Propensity score matching was used for long-term outcomes of mortality and recurrence analysis. RESULTS: After propensity score matching, 1,219 of 2,438 patients were identified in each group. The 5-year OS rates in the AS and PS groups were 97.1% and 96.0%, respectively (hazard ratio: 0.72, 95% confidence interval: 0.49-1.08), indicating the noninferiority of the AS group. Moreover, 32 patients (2.6%) in the AS group and 24 (2.0%) in the PS group had recurrences, with no significant difference between the 2 groups (odds ratio: 1.34, 95% confidence interval: 0.76-2.40, P = 0.344). DISCUSSION: ER before AS for T1 CRC had no adverse effect on patients' long-term outcomes, including the 5-year OS rate. ER is a viable first-line treatment option for endoscopically resectable T1 CRC.

Evaluation of output factors of different radiotherapy planning systems using Exradin W2 plastic scintillator detector.

This study aims to evaluate the output factors (OPF) of different radiation therapy planning systems (TPSs) using a plastic scintillator detector (PSD). The validation results for determining a practical field size for clinical use were verified. The implemented validation system was an Exradin W2 PSD. The focus was to validate the OPFs of the small irradiation fields of two modeled radiation TPSs using RayStation version 10.0.1 and Monaco version 5.51.10. The linear accelerator used for irradiation was a TrueBeam with three energies: 4, 6, and 10 MV. RayStation calculations showed that when the irradiation field size was reduced from 10 × 10 to 0.5 × 0.5 cm2, the results were within 2.0% of the measured values for all energies. Similarly, the values calculated using Monaco were within approximately 2.0% of the measured values for irradiation field sizes between 10 × 10 and 1.5 × 1.5 cm2 for all beam energies of interest. Thus, PSDs are effective validation tools for OPF calculations in TPS. A TPS modeled with the same source data has different minimum irradiation field sizes that can be calculated. These findings could aid in verification of equipment accuracy for treatment planning requiring highly accurate dose calculations and for third-party evaluation of OPF calculations for TPS.

Nutritional Status Indicators Predict Tolerability to Adjuvant Chemotherapy in Patients with Stage II/III Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy.

INTRODUCTION: Adjuvant chemotherapy (AC) after radical surgery following preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) is now the standard of care. The identification of risk factors for the discontinuation of AC is important for further improvements in survival. We herein examined the prognostic impact of chemotherapy compliance and its relationship with the prognostic nutritional index (PNI) before surgery. METHODS: A total of 335 stage II-III LARC patients who underwent preoperative CRT between 2003 and 2022 at the University of Tokyo Hospital were retrospectively reviewed. We excluded patients with recurrence during AC and those who had not received AC. The relationship between AC and long-term outcomes and that between PNI values and the duration of AC were examined. RESULTS: Thirty-one patients discontinued AC and 62 continued AC. Recurrence-free survival (RFS) was significantly shorter in patients who discontinued AC (p = 0.0056). The discontinuation of AC was identified as an independent risk factor for RFS (hazard ratio [HR]: 2.24, p = 0.0233). Twenty-one patients were classified as having low PNI (less than 40), which correlated with an older age, low body mass index, and incomplete AC. Low PNI was an independent risk factor for a shorter duration of AC (HR: 2.53, p = 0.0123). CONCLUSION: The discontinuation of AC was related to poor RFS in patients with LARC undergoing preoperative CRT. Furthermore, a low PNI value was identified as a risk factor for a shorter duration of AC.

Evaluation of anorectal function using real-time tissue elastography before and after preoperative chemoradiotherapy.

PURPOSE: This study aimed to clarify the relationship between changes in elasticity and anorectal function before and after chemoradiotherapy. METHODS: This is a single-center prospective cohort study (Department of Surgical Oncology, The University of Tokyo). We established a technique to quantify internal anal sphincter hardness as elasticity using transanal ultrasonography with real-time tissue elastography. Twenty-seven patients with post-chemoradiotherapy rectal cancer during 2019-2022 were included. Real-time tissue elastography with transanal ultrasonography was performed before and after chemoradiotherapy to measure internal anal sphincter hardness as "elasticity" (hardest (0) to softest (255); decreased elasticity indicated sclerotic changes). The relationship between the increase or decrease in elasticity pre- and post-chemoradiotherapy and the maximum resting pressure, maximum squeeze pressure, and Wexner score were the outcome measures. RESULTS: A decrease in elasticity was observed in 16/27 (59.3%) patients after chemoradiotherapy. Patients with and without elasticity decrease after chemoradiotherapy comprised the internal anal sphincter sclerosis and non-sclerosis groups, respectively. The maximum resting pressure post-chemoradiotherapy was significantly high in the internal anal sphincter sclerosis group (63.0 mmHg vs. 47.0 mmHg), and a majority had a worsening Wexner score (60.0% vs. 18.2%) compared with that of the non-sclerosis group. Decreasing elasticity (internal anal sphincter sclerosis) correlated with a higher maximum resting pressure (r = 0.36); no correlation was observed between the degree of elasticity change and maximum squeeze pressure. CONCLUSION: Internal anal sphincter sclerosis due to chemoradiotherapy may correlate to anorectal dysfunction.

Minimally invasive versus open multivisceral resection for rectal cancer clinically invading adjacent organs: a propensity score-matched analysis.

BACKGROUND: Minimally invasive surgery (MIS), such as laparoscopic and robotic surgery for rectal cancer, is performed worldwide. However, limited information is available on the advantages of MIS over open surgery for multivisceral resection for cases clinically invading adjacent organs. PATIENTS AND METHODS: This was a retrospective propensity score-matching study of consecutive clinical T4b rectal cancer patients who underwent curative intent surgery between 2006 and 2021 at the University of Tokyo Hospital. RESULTS: Sixty-nine patients who underwent multivisceral resection were analyzed. Thirty-three patients underwent MIS (the MIS group), while 36 underwent open surgery (the open group). Twenty-three patients were matched to each group. Conversion was required in 2 patients who underwent MIS (8.7%). R0 resection was achieved in 87.0% and 91.3% of patients in the MIS and open groups, respectively. The MIS group had significantly less blood loss (170 vs. 1130 mL; p < 0.0001), fewer Clavien-Dindo grade ≥ 2 postoperative complications (30.4% vs. 65.2%; p = 0.0170), and a shorter postoperative hospital stay (20 vs. 26 days; p = 0.0269) than the open group. The 3-year cancer-specific survival rate, relapse-free survival rate, and cumulative incidence of local recurrence were 75.7, 35.9, and 13.9%, respectively, in the MIS group and 84.5, 45.4, and 27.1%, respectively, in the open group, which were not significantly different (p = 0.8462, 0.4344, and 0.2976, respectively). CONCLUSION: MIS had several short-term advantages over open surgery, such as lower complication rates, faster recovery, and a shorter hospital stay, in rectal cancer patients who underwent multivisceral resection.

Differences in the Difficulty of Accessing Various 3-Dimensional Locations Under Mirror-Image Conditions During Laparoscopic Surgery.

BACKGROUND: Laparoscopic colon surgery frequently requires performing maneuvers under mirror-images conditions; the complexity differs depending on the surgical site location in the abdominal cavity. However, no previous reports have examined this. METHODS: Eleven surgeons participated in this study. Operations were performed on 25 points placed at the bottom and sides of a laparoscopic training box under mirror-image conditions. The mean time-point required to operate at each point and variation between surgeons were evaluated. RESULTS: When the right hand was used, time-points to touch the right side-superficial ends were 0.50 to 0.58 and 0.27 to 0.45 for the other sites. With the left hand, time-points to touch the left side-superficial ends were 0.58 to 0.63 and 0.28 to 0.51 for the other sites, indicating that the most difficult manipulation was at the proximal site of the surgical port. The variation in the difficulty according to the spots increased with a decrease in the surgeon's experience (right hand, r =-0.248; left hand, r =-0.491). CONCLUSIONS: In performing laparoscopic surgery under mirror-image conditions, the technical difficulty varies by location, and operating in locations close to the forceps port is the most difficult.

Modified neoadjuvant rectal score as a novel prognostic model for rectal cancer patients who underwent chemoradiotherapy.

BACKGROUND: The neoadjuvant rectal score (NAR score) has recently been proposed as a better prognostic model than the conventional TNM classification for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy. We recently developed an apoptosis-detection technique for assessing the viability of residual tumors in resected specimens after chemoradiotherapy. This study aimed to establish an improved prognostic classification by combining the NAR score and the assessment of the apoptosis of residual cancer cells. METHODS: We retrospectively enrolled 319 rectal cancer patients who underwent chemoradiotherapy followed by radical surgery. The recurrence-free survival and overall survival of the four models were compared: TNM stage, NAR score, modified TNM stage by re-staging according to cancer cell viability, and modified NAR score also by re-staging. RESULTS: Downstaging of the ypT stage was observed in 15.5% of cases, whereas only 4.5% showed downstaging of ypN stage. C-index was highest for the modified NAR score (0.715), followed by the modified TNM, TNM, and NAR score. Similarly, Akaike's information criterion was smallest in the modified NAR score (926.2), followed by modified TNM, TNM, and NAR score, suggesting that the modified NAR score was the best among these four models. The overall survival results were similar: C-index was the highest (0.767) and Akaike's information criterion was the smallest (383.9) for the modified NAR score among the four models tested. CONCLUSION: We established a novel prognostic model, for rectal cancer patients that have undergone neoadjuvant chemoradiotherapy, using a combination of apoptosis-detecting immunohistochemistry and neoadjuvant rectal scores.

Local excision versus radical surgery for anal squamous cell carcinoma: a multicenter study in Japan.

BACKGROUND: The standard treatment for anal squamous cell carcinoma is chemoradiation therapy (CRT), but there is a possibility of over-treatment for early-stage disease. cTisN0 and cT1N0 disease is currently indicated for local excision, but it is unclear whether the indication of local excision can be expanded to cT2N0 disease. METHODS: 126 patients with cTis-T2N0 anal cancer treated at 47 centers in Japan between 1991 and 2015 were included. Patients were first classified into the CRT group and surgical therapy group according to the initial therapy, and the latter was further divided into local excision (LE) and radical surgery (RS) groups. We compared prognoses among the groups, and analyzed risk factors for recurrence after local excision. RESULTS: The CRT group (n = 87) and surgical therapy group (n = 39) showed no difference in relapse-free survival (p = 0.29) and overall survival (p = 0.94). Relapse-free survival curves in the LE (n = 23) and RS groups (n = 16) overlapped for the initial 3 years, but the curve for the LE group went lower beyond (p = 0.33). By contrast, there was no difference in overall survival between the two groups (p = 0.98). In the LE group, the majority of recurrences distributed in locoregional areas, which could be managed by salvage treatments. Muscular invasion was associated with recurrence after local excision (hazard ratio: 22.91, p = 0.011). CONCLUSION: LE may be applied to selected patients with anal cancer of cTis-T2N0 stage. Given the high risk of recurrence in cases with muscular invasion, it may be important to consider close surveillance and additional treatment in such patients.