Long-term survival and functional outcomes of laparoscopic surgery for clinical stage I ultra-low rectal cancers located within 5 cm of the anal verge: A prospective phase II trial (Ultimate trial).

OBJECTIVE: To clarify the long-term oncological outcomes and postoperative anal, urinary, and sexual functions after laparoscopic surgery for clinical stage I very low rectal carcinoma located near the anal canal. SUMMARY BACKGROUND DATA: Laparoscopic surgery is widely applied for rectal cancer; however, concerns remain, with some studies showing poorer outcomes compared to open surgery. METHODS: This single-arm, phase II trial included patients registered preoperatively from 47 institutions in Japan. The planned sample size was 300. The primary endpoint was the 3-year local recurrence rate. Anal, urinary, and sexual functions were evaluated using a prospective questionnaire. RESULTS: Three-hundred patients were registered between January 2014 and March 2017. Anus-preserving surgery was performed in 278 (93%), including 172 who underwent intersphincteric resection (58%) and 106 (36%) who underwent low anterior resection. The 3-year cumulative local recurrence rate was 6.3%. At 3 years postoperatively, 87% of patients used their own anus, and the median incontinence score improved from 12 at 3 months to 8 at 3 years. Only 5% of patients had severe incontinence (incontinence score of 16 points). Postoperative urinary function evaluation showed that International Prostate Symptom Score and Overactive Bladder Symptom Score decreased 1 week after surgery, but recovered to preoperative level 1 month after surgery. International Consultation on Incontinence Questionnaire-Sort Form remained almost stable after surgery. Sexual function evaluation using the International Index of Erectile Function-5 and International Index of Erectile Function-15 revealed that the patients had deteriorated 3 months after surgery but had recovered only slightly by 6 months. CONCLUSIONS: Laparoscopic surgery achieves feasible long-term oncological outcomes and a high rate of anus preservation with moderate anal function, and an acceptable incontinence score. While urinary function recovered rapidly, sexual function showed poor recovery.

Incidence of low anterior resection syndrome and its association with the quality of life in patients with lower rectal tumors.

PURPOSE: Low anterior resection syndrome (LARS) causes devastating symptoms and impairs the quality of life (QOL). This study investigated the incidence and risk factors of LARS and their association with the QOL in patients with lower rectal tumors. METHODS: Patients who underwent anus-preserving surgery for lower rectal tumors between 2014 and 2019 and who had anal defecation between 2020 and 2021 were surveyed. The LARS score measured severity, and the QOL was evaluated using the Japanese version of the Fecal Incontinence Quality-of-Life Scale (JFIQL). The primary endpoint was the incidence of Major LARS, and the secondary endpoints were risk factors and association with the JFIQL. RESULTS: Of 107 eligible patients, 82 (76.6%) completed the LARS survey. The incidence of Major LARS was 48%. Independent risk factors included neoadjuvant chemoradiotherapy (CRT) and a short interval (< 24 months after surgery; odds ratio, 4.6; 95% confidence interval: 1.1-19, both). The LARS score was moderately correlated with the JFIQL generic score (correlation coefficient: - 0.54). The JFIQL scores were significantly worse in the Minor and Major LARS groups than in the No LARS group. CONCLUSIONS: Major LARS was found in 48% of lower rectal tumors, and independent risk factors include neoadjuvant CRT and a short interval. The QOL was significantly impaired in patients with both Minor and Major LARS.

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.

Impact of Preoperative Stoma Site Marking on Morbidity and Mortality in Patients with Colorectal Perforation: A Nationwide Retrospective Cohort Study.

BACKGROUND: Preoperative stoma site marking reduces the incidence of complications from elective surgery. However, the impact of stoma site marking in emergency patients with colorectal perforation remains unclear. This study aimed to assess the impact of stoma site marking on morbidity and mortality in patients with colorectal perforation who underwent emergency surgery. METHODS: This retrospective cohort study used the Japanese Diagnosis Procedure Combination inpatient database from April 1, 2012, to March 31, 2020. We identified patients who underwent emergency surgery for colorectal perforation. We compared outcomes between those with and without stoma site marking using propensity score matching to adjust for confounding factors. The primary outcome was the overall complication rate, and the secondary outcomes were stoma-related, surgical, and medical complications and 30-day mortality. RESULTS: We identified 21,153 patients (682 with stoma site marking and 20,471 without stoma site marking) and grouped them into 682 pairs using propensity score matching. The overall complication rates were 23.5% and 21.4% in the groups with and without stoma site marking, respectively (p = 0.40). Stoma site marking was not associated with a decrease in stoma-related, surgical, or medical complications. The 30-day mortality did not differ significantly between the groups with and without stoma site marking (7.9% vs. 8.4%, p = 0.843). CONCLUSIONS: Preoperative stoma site marking was not associated with a reduction in morbidity and mortality in patients with colorectal perforation who underwent emergency surgery.

NLRP3 Inflammasome Activation in Lung Vascular Endothelial Cells Contributes to Intestinal Ischemia/Reperfusion-Induced Acute Lung Injury.

Intestinal ischemia/reperfusion (I/R) injury is a life-threatening complication that leads to inflammation and remote organ damage. The NLRP3 inflammasome regulates the caspase-1-dependent release of IL-1ß, an early mediator of inflammation after I/R injury. In this study, we investigated the role of the NLRP3 inflammasome in mice with intestinal I/R injury. Deficiency of NLRP3, ASC, caspase-1/11, or IL-1ß prolonged survival after intestinal I/R injury, but neither NLRP3 nor caspase-1/11 deficiency affected intestinal inflammation. Intestinal I/R injury caused acute lung injury (ALI) characterized by inflammation, reactive oxygen species generation, and vascular permeability, which was markedly improved by NLRP3 deficiency. Bone marrow chimeric experiments showed that NLRP3 in non-bone marrow-derived cells was the main contributor to development of intestinal I/R-induced ALI. The NLRP3 inflammasome in lung vascular endothelial cells is thought to be important to lung vascular permeability. Using mass spectrometry, we identified intestinal I/R-derived lipid mediators that enhanced NLRP3 inflammasome activation in lung vascular endothelial cells. Finally, we confirmed that serum levels of these lipid mediators were elevated in patients with intestinal ischemia. To our knowledge, these findings provide new insights into the mechanism underlying intestinal I/R-induced ALI and suggest that endothelial NLRP3 inflammasome-driven IL-1ß is a novel potential target for treating and preventing this disorder.

Programmed cell death ligand 1 expression on monocytes is inversely correlated with tumour response to preoperative chemoradiotherapy for locally advanced rectal cancer.

AIM: The clinical efficacy of chemoradiotherapy (CRT) is largely dependent on host immune status. The aim of this study was to identify possible markers expressed on circulating mononuclear cells to predict tumour response in patients with locally advanced rectal cancer (LARC). METHODS: Peripheral blood samples were obtained from 47 patients diagnosed with LARC before and after CRT. The numbers of lymphocytes and monocyte subsets were analysed using flow cytometry. Based on clinical and pathological findings, patients were classified as high or low responders. RESULTS: Lymphocyte counts were markedly decreased after CRT. Total numbers of lymphocytes (p = 0.030) and CD4(+) T cells (p = 0.041) in post-CRT samples were significantly lower in low responders than in high responders. In contrast, monocyte counts were not reduced and the number of CD14dim (+) CD16(+) nonclassical (patrolling) monocytes were somewhat increased after CRT (p = 0.050). Moreover, the ratios of programmed cell death ligand 1 (PD-L1) (+) cells on patrolling monocytes before and after CRT were significantly higher in low responders than in high responders (p = 0.0046, p = 0.0006). The same trend was observed for classical and intermediate monocytes. The expression of PD-L1 on patrolling monocytes before CRT correlated inversely with the number of T cells and natural killer (NK) cells after CRT. PD-L1(+) ratio in patrolling monocytes was an independent predictor for response to CRT. CONCLUSION: Programmed cell death ligand 1 (PD-L1) expression on patrolling monocytes suppresses cell-mediated immunity in patients receiving CRT which could be related to tumour response, and may be a useful biomarker for decision-making in the management of patients with LARC.

The Regional Specificity of Mucosa-Associated Microbiota in Patients with Distal Colorectal Cancer.

BACKGROUND/AIMS: Recent studies have demonstrated that the populations of several microbes are significantly increased in fecal samples from patients with colorectal cancer (CRC), suggesting their involvement in the development of CRC. The aim of this study was to identify microbes which are increased in distal CRCs and to identify the specific location of microbes increased in mucosal tissue around the tumor. METHODS: Tissue specimens were collected from surgical resections of 28 distal CRCs. Five samples were collected from each specimen (location A: tumor, B: adjacent normal mucosa, C: normal mucosa 1 cm proximal to the tumor, D: normal mucosa 3 cm proximally, and E: normal mucosa 6 cm proximally). The microbiota in the sample were analyzed using 16S rRNA gene amplicon sequencing and the relative abundance (RA) of microbiota compared among the 5 locations. RESULTS: At the genus level, the RA of Fusobacterium and Streptococcus at location A was the highest among the 5 locations, significantly different from that in location E. The dominant species of each genus was Fusobacterium nucleatum and Streptococcus anginosus. The RAs of these species gradually decreased from locations B to E with a statistically significant difference in F. nucleatum. The genus Peptostreptococcus also showed a similar trend, and the RA of Peptostreptococcus stomatis in location A was significantly associated with depth of tumor invasion and tumor size. CONCLUSION: Although the clinical relevance is not clear yet, these results suggest that F. nucleatum, S. anginosus, and P. stomatis can spread to the adjacent normal tissues and may change the surrounding microenvironment to support the progression of CRC.

Intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine model.

PURPOSE: The aim of this study was to evaluate both the intestinal mucosa staple line integrity and anastomotic leak pressure after healing in a porcine survival model. METHODS: We used two suture models using two different size staples (incomplete mucosal closure model: group G [staple height 0.75 mm], complete mucosal closure model: group B [staple height 1.5 mm]) in the porcine ileum. Five staple lines were created in each group made in the ileum for each model, and the staple sites harvested on days 0, 2, and 7. The leak pressure at the staple site was measured at each time point. RESULTS: On day 0, the leak pressure for group G (79.5 mmHg) was significantly lower than that for group B (182.3 mmHg) (p < 0.01). On days 2 and 7, there was no significant difference between groups G and B (171 mmHg and 175.5 mmHg on day 2, 175.5 mmHg and 175.5 mmHg on day 7, p > 0.05). The histological findings in both groups showed similar healing at postoperative days 2 and 7. CONCLUSION: The integrity of the mucosal staple lines was associated with the postoperative leak pressure on day 0. However, there was no association with the leak pressure at two days or more postoperatively in a porcine model.

Metformin changes the immune microenvironment of colorectal cancer in patients with type 2 diabetes mellitus.

Accumulating evidence suggests that metformin reduces the incidence and mortality of colorectal cancer (CRC). However, underlying mechanisms have not been fully clarified. The aim of this study was to examine the pathological characteristics of resected CRC from patients treated with metformin for type 2 diabetes mellitus (DM). In total, 267 patients with DM underwent curative colectomy for Stage I-III CRC and 53 (19.9%) patients had been treated medically including metformin. Pathological N-stage was significantly lower in metformin-treated patients (P < .05) with prolonged disease-free survival (DFS) (P < .05). Immunohistochemistry showed that the densities of CD3(+) and CD8(+) tumor-infiltrating lymphocytes (TILs) in the invasive front area were significantly higher in 40 patients treated with metformin compared with propensity score matched cases without metformin (P < .05). The density of tertiary lymphoid structures (TLS) in tumor stroma was markedly increased in metformin-treated patients (P < .001). In those tumors, there were more CD68(+) tumor-associated macrophages (TAM) infiltrated (P < .05), while the ratio of CD163(+) M2-phenotype was markedly reduced (P < .001). Stromal fibrosis tended to be suppressed by metformin intake (P = .051). These findings suggested that metformin drastically changes the characteristics of infiltrating immune cells in CRC and reprograms the tumor microenvironment from immunosuppressive to immunocompetent status, which may lead to suppression of microscopic tumor spread and improve the outcomes of patients with CRC and type 2 DM.

Ratios of miRNAs in Peritoneal Exosomes are Useful Biomarkers to Predict Tumor Response to Intraperitoneal Chemotherapy in Patients with Peritoneal Metastases from Gastric Cancer.

BACKGROUND: Repeat intraperitoneal (IP) chemotherapy has been successfully used for treatment of peritoneal metastases (PM) from gastric cancer (GC). Exosomes play important roles not only in tumor progression but also in chemoresistance via transfer of microRNAs (miRNAs). However, there is little evidence of an effect of miRNAs in peritoneal exosomes on chemosensitivity of peritoneal lesions. METHODS: In 74 patients with advanced GC who underwent staging laparoscopy, exosomes were isolated from peritoneal fluid and expression levels of miR-21-5p, miR-223-3p, and miR-29b-3p determined using TaqMan Advanced miRNA assays. In 43 patients with PM treated with combination chemotherapy, S-1 plus Oxaliplatin together with IP Paclitaxel, the relationship between their relative expression levels and outcomes was examined. RESULTS: The ratios of miR-21-5p/miR-29b-3p and miR-223-3p/miR-29b-3p were significantly upregulated in patients with PM, especially in patients with high serum CA125 levels. They showed a mild association with Peritoneal Cancer Index (PCI) score and ascites. More impressively, the ratios were significantly higher in 16 patients with progression of PM within 1 year compared with 27 patients with an excellent tumor response (miR-21-5p/miR-29b-3p: median 17.49, range 1.83-50.90 vs. median 4.64, range 0.40-38.96, p = 0.0015, miR-223-3p/miR-29b-3p: median 1.02, range 0.23-25.85 vs. median 0.21, range 0.01-50.07, p = 0.0006). Overall survival of patients with high miR-21/miR-29b or miR-223/miR-29b ratios was significantly worse than in patients with low ratios (p = 0.0117, p = 0.0021). CONCLUSIONS: The ratios of miRNAs in peritoneal exosome correlate with survival of the patients with PM from GC and suggest the possibility that they modify the chemosensitivity against IP chemotherapy.

CD73 blockade enhances the local and abscopal effects of radiotherapy in a murine rectal cancer model.

BACKGROUND: Anti-tumor effects of radiation therapy (RT) largely depend on host immune function. Adenosine with its strong immunosuppressive properties is an important immune checkpoint molecule. METHOD: We examined how intra-tumoral adenosine levels modify anti-tumor effects of RT in a murine model using an anti-CD73 antibody which blocks the rate-limiting enzyme to produce extracellular adenosine. We also evaluated CD73 expression in irradiated human rectal cancer tissue. RESULTS: LuM-1, a highly metastatic murine colon cancer, expresses CD73 with significantly enhanced expression after RT. Subcutaneous (sc) transfer of LuM-1 in Balb/c mice developed macroscopic sc tumors and microscopic pulmonary metastases within 2 weeks. Adenosine levels in the sc tumor were increased after RT. Selective RT (4Gyx3) suppressed the growth of the irradiated sc tumor, but did not affect the growth of lung metastases which were shielded from RT. Intraperitoneal administration of anti-CD73 antibody (200 µg × 6) alone did not produce antitumor effects. However, when combined with RT in the same protocol, anti-CD73 antibody further delayed the growth of sc tumors and suppressed the development of lung metastases presumably through abscopal effects. Splenocytes derived from RT+ CD73 antibody treated mice showed enhanced IFN-γ production and cytotoxicity against LuM-1 compared to controls. Immunohistochemical studies of irradiated human rectal cancer showed that high expression of CD73 in remnant tumor cells and/or stroma is significantly associated with worse outcome. CONCLUSION: These results suggest that adenosine plays an important role in the anti-tumor effects mediated by RT and that CD73/adenosine axis blockade may enhance the anti-tumor effect of RT, and improve the outcomes of patients with locally advanced rectal cancer.

Surgical Stress Increases Circulating Low-Density Neutrophils Which May Promote Tumor Recurrence.

BACKGROUND: Low-density neutrophils (LDN) have been shown to be increased in peripheral blood in patients with various diseases and closely related to immune-mediated pathology. However, the frequency and function of LDN in circulating blood of the patients following abdominal surgery have not been well understood. METHODS: LDN were determined by CD66b(+) cells, which were copurified with mononuclear cells by density gradient preparations of peripheral blood of surgical patients. The effects of the purified LDN on T cell proliferation and tumor cell lysis were examined in vitro. Neutrophil extracellular traps (NETs) production was examined by extracellular nuclear staining. RESULTS: The number of LDN with an immature phenotype is markedly increased in peripheral blood samples in patients after abdominal surgery. The frequency of LDN correlated positively with operative time and intraoperative blood loss. The purified LDN significantly suppressed the proliferation of autologous T cells stimulated with anti-CD3 mAb coated on plate and partially inhibited the cytotoxicity of lymphocytes activated with recombinant interleukin-2 against a human gastric cancer cell, OCUM-1. The LDN also produced NETs after short-term culture in vitro, which efficiently trap many OCUM-1. These results suggest that surgical stress recruits immunosuppressive LDN in the circulation in the early postoperative period. CONCLUSIONS: The LDN may support the lodging of circulating tumor cells via NETs formation and inhibit T cell-mediated antitumor response in target organs, which may promote postoperative cancer metastases. Functional blockade of LDN might be an effective strategy to reduce tumor recurrence after abdominal surgery.

Role of TLR5 in inflammation and tissue damage after intestinal ischemia-reperfusion injury.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) injury is a life-threatening complication that leads to inflammation and remote organ damage. However, the underlying mechanism is not yet fully understood. Toll-like receptor 5 (TLR5) is highly expressed in mucosa and recognizes flagellin, the main component of the bacterial flagella. Here, we investigated the role of TLR5 in inflammation and tissue damage after intestinal I/R injury using TLR5-deficient mice. METHODS AND RESULTS: Intestinal levels of TLR5 mRNA and flagellin protein were elevated in wild-type mice subjected to intestinal I/R. Although TLR5 deficiency had no effect on intestinal flagellin levels, it significantly attenuated intestinal injury and inflammatory responses after intestinal I/R. TLR5 deficiency also markedly improved survival in mice after intestinal I/R injury. In wild-type mice, intestinal I/R injury induced remote organ damage, particularly in the lung, which was attenuated by TLR5 deficiency. Furthermore, TLR5 deficiency prevented lung inflammatory responses and vascular permeability after intestinal I/R injury. CONCLUSION: These findings demonstrate a novel role of TLR5 and provide new insights into the mechanism underlying inflammation and tissue damage after intestinal I/R injury.

Interaction of Neutrophils with Macrophages Promotes IL-1ß Maturation and Contributes to Hepatic Ischemia-Reperfusion Injury.

Accumulating evidence suggests that IL-1ß plays a pivotal role in the pathophysiology of hepatic ischemia-reperfusion (I/R) injury; however, the mechanism by which I/R triggers IL-1ß production in the liver remains unclear. Recent data have shown that neutrophils contribute to hepatic I/R injury independently of the inflammasomes regulating IL-1ß maturation. Thus, we investigated the role of neutrophils in IL-1ß maturation and tissue injury in a murine model of hepatic I/R. IL-1ß was released from the I/R liver and its deficiency reduced reactive oxygen species generation, apoptosis, and inflammatory responses, such as inflammatory cell infiltration and cytokine expression, thereby resulting in reduced tissue injury. Depletion of either macrophages or neutrophils also attenuated IL-1ß release and hepatic I/R injury. In vitro experiments revealed that neutrophil-derived proteinases process pro-IL-1ß derived from macrophages into its mature form independently of caspase-1. Furthermore, pharmacological inhibition of serine proteases attenuated IL-1ß release and hepatic I/R injury in vivo. Taken together, the interaction between neutrophils and macrophages promotes IL-1ß maturation and causes IL-1ß-driven inflammation in the I/R liver. Both neutrophils and macrophages are indispensable in this process. These findings suggest that neutrophil-macrophage interaction is a therapeutic target for hepatic I/R injury and may also provide new insights into the inflammasome-independent mechanism of IL-1ß maturation in the liver.

Thymoma with an isolated splenic metastasis eight years after extended thymectomy: a case report.

BACKGROUND: Thymomas are typically slow-growing tumors and AB type thymomas are considered no/low risk tumors with a better prognosis. Extra-thoracic metastases are extremely rare. To the best of our knowledge, no patient with an isolated splenic metastasis from a thymoma has been reported. We report a patient who underwent laparoscopic splenectomy for a slow-growing, isolated splenic metastasis, eight years after thymectomy. CASE PRESENTATION: The patient is a 78-year-old man. Eight years previously, the patient underwent extended thymectomy and postoperative radiation therapy for a thymoma. Five years after thymectomy, a nodule appeared in the spleen, and the lesion enlarged gradually for three years thereafter. The patient was referred for further examination and treatment. Computed tomography scan showed a sharply circumscribed 50 mm tumor slightly hypodense and heterogeneous lesion in the spleen. On T2-weighted images on Magnetic Resonance Imaging, the tumor had high intensity, equivalent to or slightly lower than that on T1-weighted images, and no decrease on diffusion-weighted images. The tumor was multinodular and showed a low-signal spoke-wheel sign in the margin, enhanced gradually in the dynamic study. Positron emission tomography-CT scan, showed relatively low accumulation. Surgical resection was undertaken, and pathological examination showed metastatic thymoma. The patient is without recurrence and has no other symptoms three years after splenectomy. CONCLUSIONS: This is the first report of an isolated splenic metastasis from a thymoma. Further cases are needed to standardize this surgery for such lesions.

Efficacy and safety of endoscopic submucosal dissection for superficial colorectal tumors more than 50 mm in diameter.

BACKGROUND AND AIMS: The feasibility of endoscopic submucosal dissection (ESD) for large superficial colorectal tumors is undefined. The aim of this study was to assess the outcomes for patients undergoing ESD of superficial colorectal tumors larger than 50 mm. METHODS: A total of 472 patients who underwent ESD for superficial colorectal tumors from 2010 to 2014 were enrolled. We retrospectively reviewed their records. RESULTS: We compared patients with 20-mm to 50-mm lesions and those with lesions >50 mm regarding demographics, the ESD procedure, and histopathology. Among patients with lesions >50 mm, laterally spreading tumors nongranular and protruded types were uncommon. Histopathologically, deeply invasive (≥1000 µm) submucosal carcinomas were more frequent in lesions >50 mm (14% [10/70] vs 5% [20/402], P < .01). Technically, en bloc resection was successfully accomplished in 99% of patients (69/70). Although the total dissection time for lesions >50 mm was significantly longer than for lesions 20 mm to 50 mm (mean ± SD, 157 ± 114 minutes vs 68 ± 50 min; P < .01), dissection speed for lesions >50 mm was significantly faster than for lesions 20 mm to 50 mm (P < .01). There were no significant differences in en bloc R0 resection rate comparing both groups (>50 mm, 83% vs 20 mm to 50 mm, 87%; P = .31). No perforations or postoperative bleeding occurred in patients with lesions >50 mm. Post-ESD colorectal strictures requiring intervention did not develop in any patient. CONCLUSIONS: ESD for superficial colorectal tumors >50 mm is feasible. ESD of these lesions had a high R0 resection rate and a low adverse event rate. En bloc resection by ESD provides adequate pathological specimens and may limit the need for surgical intervention.

Laparoscopic versus open surgery for colorectal cancer in elderly patients: a multicenter matched case-control study.

BACKGROUND: The safety of laparoscopic surgery (LAP) in elderly patients with colorectal cancer has not been demonstrated. The aim of this study was to compare the outcomes of LAP and open surgery (OP) and estimate the feasibility of LAP in colorectal cancer patients aged ≥ 80 years. METHODS: We conducted a propensity scoring matched case-control study of colon and rectal cancer patients aged ≥ 80 years using data from 41 hospitals between 2003 and 2007. A total of 1,526 colon cancer patients and 282 rectal cancer patients underwent surgery and were included in the analysis. The primary end point was 3-year overall survival (OS). Secondary end points included disease-free survival (DFS), cancer-specific survival (CSS), and postoperative complications. RESULTS: LAP and OP were compared in 804 colon cancer patients (402 pairs) and 114 rectal cancer patients (57 pairs) after all covariates were balanced, and no significant differences were observed, except for tumor size in colon cancer. OS, DFS, and CSS did not differ between the groups for either colon cancer (P = 0.916, 0.968, and 0.799, respectively) or rectal cancer (P = 0.765, 0.519, and 0.950, respectively). In colon cancer cases, LAP was associated with fewer morbidities than was OP (24.9 vs. 36.3 %, P < 0.001); no such difference was observed for rectal cancer patients (47.4 vs. 40.4 %, P = 0.450). CONCLUSIONS: LAP is an acceptable alternative to OP in elderly patients with colorectal cancer.

Multiple primary malignancies involving primary sporadic colorectal cancer in Japan: incidence of gastric cancer with colorectal cancer patients may be higher than previously recognized.

BACKGROUND: Improvement in the prognosis of colorectal cancer (CRC) patients has led to increasing occurrences of multiple primary malignancies (MPMs) alongside CRC but little is known about their characteristics. This study was undertaken to clarify the clinical and pathological features of MPMs, especially those at extra colonic sites, in patients with CRC. METHODS: We reviewed 1,111 patients who underwent operations for primary sporadic CRC in Saitama Medical Center, Jichi Medical University between April 2007 and March 2012. Two patients with familial adenomatous polyposis, one with hereditary non-polyposis colorectal cancer, two with colitic cancer, and any patients with metastasis from CRC were excluded. We compared the clinicopathological features of CRC patients with and without MPMs. As a control, we used a database compiled of patients with gastric cancer (GC) detected by mass screening performed in the Saitama Prefecture in Japan 2010 and compared these with CRC patients with synchronous GC. RESULTS: Multiple primary malignancies at extracolonic sites were identified in 117 of 1,111 CRC patients (10.5%). The median age was 68 (range, 29 to 96) versus 71 (50 to 92) (P < 0.001). The incidence of GC (44.4% (52 of 117)) was the highest of all MPMs. All CRC patients with GC were older than 57 years. Synchronous GC was detected in 26 patients. By contrast, out of 200,007 screened people, 225 people were diagnosed as having GC in the Saitama Prefecture. The age-standardized incidence of synchronous GC in CRC patients was significantly higher (0.53%) than in the control group (0.03%) (odds ratio, 18.8; 95% confidence interval, 18.6 to 19.0; P < 0.001). CONCLUSION: Patients with CRC who were older than 50 years preferentially developed GC synchronously and metachronously. Thus, this patient group should undergo careful perioperative screening for GC.