Single-incision Laparoscopic Colonic Surgery: A Systemic Review, Meta-analysis, and Future Prospect

Although single-incision laparoscopic surgery (SILS) has gained some attention as a feasible alternative to conventional multiport laparoscopic surgery (MPLS) in colonic surgery, it became less prevalent than expected. Hence, we conducted this systematic review to evaluate the feasibility, safety, and oncological outcomes of single-incision laparoscopic colectomy (SILC) with meta-analysis and discussion of the future prospect of SILS. The search was conducted from September to October 2023 using PubMed and the Cochrane Central Register of Controlled Trials. Articles on colorectal cancer comparing SILC with multiport laparoscopic colectomy (MPLC) from all randomized controlled trials and comparative studies with 50 patients or more per arm were examined. The primary outcomes were the intra- and postoperative complication rates, and the secondary outcomes were the perioperative and oncological outcomes. The trends of the SILS number in Japan and the trends of the number of articles on SILS in PubMed were also reviewed. There were no significant differences in perioperative complication rates, operative factors, and oncological outcomes between SILC and MPLC, although heterogeneity was observed mainly in operative factors and the total length of the skin incision was significantly shorter in SILC. Therefore, SILC is technically and oncologically feasible and safe when performed by experienced laparoscopic surgeons. The case number of SILS was gradually increasing but the rate of SILS was decreasing in Japan. The number of articles on SILS was also decreasing. SILS has gained foothold to some extent but has plateaued. The emerging new robotic platform may reappraise the concept of SILS.

Comparison of clinical outcomes of single-incision versus multi-port laparoscopic surgery for descending colon cancer: a propensity score-matched analysis

BACKGROUND

The clinical impact of single-incision laparoscopic surgery (SILS) for descending colon cancer (DCC) is unclear. The aim of this study was to evaluate the clinical outcomes of SILS for DCC compared with multi-port laparoscopic surgery (MPLS).

METHODS

We retrospectively analyzed 137 consecutive patients with stage I-III DCC who underwent SILS or MPLS at two high-volume multidisciplinary tertiary hospitals between April 2008 and December 2018, using propensity score-matched analysis.

RESULTS

After propensity score-matching, we enrolled 88 patients (n = 44 in each group). SILS was successful in 97.7% of the matched cohort. Compared with the MPLS group, the SILS group showed significantly less blood loss and a greater number of harvested lymph nodes. Morbidity rates were similar between groups. Recurrence pattern did not differ between groups. No significant differences were found between groups in terms of 3-year disease-free and overall survivals.

CONCLUSION

SILS appears safe and feasible and can provide satisfactory oncological outcomes for patients with DCC.

Magnetic fields and relativistic electrons fill entire galaxy cluster

The hot plasma within merging galaxy clusters is predicted to be filled with shocks and turbulence that may convert part of their kinetic energy into relativistic electrons and magnetic fields generating synchrotron radiation. Analyzing Low Frequency Array (LOFAR) observations of the galaxy cluster Abell 2255, we show evidence of radio synchrotron emission distributed over very large scales of at least 5 megaparsec. The pervasive radio emission witnesses that shocks and turbulence efficiently transfer kinetic energy into relativistic particles and magnetic fields in a region that extends up to the cluster outskirts. The strength of the emission requires a magnetic field energy density at least 100 times higher than expected from a simple compression of primordial fields, presumably implying that dynamo operates efficiently also in the cluster periphery. It also suggests that nonthermal components may contribute substantially to the pressure of the intracluster medium in the cluster periphery.

Clinical outcomes of single incision laparoscopic surgery for colorectal cancer: A propensity score-matched analysis between well-experienced and novice surgeons

Background

Single incision laparoscopic surgery (SILS) is a recent advancement in minimally invasive techniques for colorectal cancer (CRC). However, SILS is a technically challenging procedure for novice surgeons. The aim of this study was to evaluate clinical outcomes of SILS for CRC performed by novice surgeons compared with those performed by well-experienced surgeons.

Methods

We retrospectively analyzed 1004 consecutive patients with stage I-IV CRC who underwent SILS between May 2009 and December 2018, using propensity score-matched analysis.

Results

After propensity score-matching, we enrolled 344 patients (n = 172 in each group). Before matching, significant group-dependent differences were observed in terms of age (P = 0.034) and tumor location (P < 0.001). After matching, preoperative clinical factors were similar between groups, but operative time was longer in the Novice group (213 vs 171 min, P < 0.001). Other operative factors and morbidity rates did not differ significantly between groups. The number of harvested lymph nodes was smaller in the Novice group (23 vs 25, P = 0.040), and the number of patients with lymph node metastases was smaller in the Novice group (57 vs 86, P = 0.002). The 3-year disease-free survival rate was 85.8% in the Novice group and 89.9% in the Experienced group (P = 0.512). Three-year overall survival rate was 92.2% in the Novice group and 90.0% in the Experienced group (P = 0.899).

Conclusion

SILS for CRC was safely performed by novice surgeons under the guidance of well-experienced surgeons, and could provide satisfactory oncological outcomes.

Comparison of clinical outcomes of single-incision versus multi-port laparoscopic surgery for rectosigmoid or upper rectal cancer

BACKGROUND

Single-incision laparoscopic surgery (SILS) for rectal cancer is technically challenging, and its clinical impact is unclear. The aim of this study was to evaluate clinical outcomes of SILS for rectal cancer compared with multi-port laparoscopic surgery (MPLS).

PATIENTS AND METHODS

We retrospectively analyzed 357 consecutive patients with stage I-III rectal cancer located in the rectosigmoid or upper rectum who underwent SILS or MPLS between January 2012 and December 2016, using propensity score-matched analysis.

RESULTS

After propensity score-matching, we enrolled 204 patients (n = 102 per group). Before matching, significant group-dependent differences were observed in tumor location (p < 0.001). After matching, preoperative clinical factors were similar between groups. SILS was successful in 73.5% of cases, an additional port was required in 23.5%, and 2.9% were converted to open surgery. Compared to the MPLS group, the SILS group showed shorter operative time (192 vs. 211 min, p = 0.015) and shorter postoperative hospital stay (9 vs. 11 days, p = 0.038). Other operative factors and morbidity rates did not differ significantly between groups. The number of harvested lymph nodes was smaller in the SILS group (24) than in the MPLS group (27, p = 0.008). Postoperative recurrence did not differ between groups, either before or after matching. No significant differences in 3-year disease-free, 3-year local recurrence-free, or 5-year overall survival were found between groups.

CONCLUSIONS

SILS is safe, is feasible, and offers satisfactory oncological outcomes in selected patients with rectosigmoid or upper rectal cancer.

Vascular variants in laparoscopic extended right hemicolectomy with central vascular ligation for right colon cancer

PURPOSE

To evaluate the right colic vascularity, focusing on the confluences of veins.

METHODS

The subjects of this retrospective study were 100 patients who underwent laparoscopic extended right hemicolectomy (Lap-ERHC) between April 2015 and September 2020, at our hospitals. Veins draining into the superior mesenteric vein (SMV) included the ileocecal vein (ICV), the right colic vein (RCV), the middle colic vein (MCV), and the gastrocolic trunk of Henle (GCT). Veins draining into vessels other than the SMV were defined as accessory colic veins (aICV, aRCV or aMCV).

RESULTS

The GCT, aRCV, and aMCV were found in 86, 89, and 15 patients, respectively. In 66 patients with one aRCV, drainage was split as the anterior superior pancreaticoduodenal vein (ASPDV) in 12, the right gastroepiploic vein (RGEV) in 7, and the GCT in 47. In 23 patients with two aRCVs, drainage was split as the ASPDV in 4, the RGEV in 1, the GCT in 11, and the ASPDV and GCT in 7. In 14 patients with one aMCV, drainage was split as the GCT in 8, the splenic vein in 5, and the first jejunal vein (FJV) in 1. One patient had two aMCVs, draining into the GCT and the FJV.

CONCLUSIONS

The findings of our evaluation of vascular anatomy, focusing on confluences of the colic veins, provides useful information for colorectal surgeons.

Single-Incision Laparoscopic Complete Mesocolic Excision With Central Vascular Ligation for Descending Colon Cancer

Background

Single-incision laparoscopic complete mesocolic excision with central vascular ligation for descending colon cancer is technically challenging. Standardization of the surgical procedures is therefore needed.

Methods

In a Trendelenburg position with left side elevated, the sigmoid mesocolon is mobilized using a medial-to-lateral approach, and the left colic artery and inferior mesenteric vein (IMV) are divided after radical lymphadenectomy along the inferior mesenteric artery, preserving the superior rectal artery. The descending mesocolon is mobilized from the retroperitoneal planes up to the dorsal surface of the pancreas using medial and lateral approaches. Next, changing the surgical position to a reverse Trendelenburg position with left side elevated, the omental bursa is opened, and the transverse mesocolon is separated from the inferior border of the pancreas. The splenocolic ligament and lateral attachment are then divided, matching the previous medial dissection of the retroperitoneum, and the splenic flexure is fully mobilized. The IMV is divided again at the inferior border of the pancreas. The left branch of the middle colic artery is also divided.

Results

Forty-seven consecutive patients with DCC underwent single-incision laparoscopic CME with CVL. One patient required an additional port. Median operative time, blood loss, and number of harvested lymph nodes were 240 min (interquartile range [IQR], 195-257 min), 5 mL (IQR, 5-52 mL), and 21 (IQR, 13-29), respectively. Morbidity rate was 5.9%. Median duration of hospitalization was 9 days (IQR, 7-11 days).

Conclusions

Single-incision laparoscopic CME with CVL is safe and feasible for DCC.

[A Case of Carcinomatous Meningitis from Gastric Cancer with Improvement of QOL by Ventriculoperitoneal Shunt]

In cases where carcinomatous meningitis leads to hydrocephalus and increases intracranial pressure, patients present with exacerbated pain and several neurological symptoms. It is reported that multidisciplinary therapy, including radiation therapy, drug therapy, and surgery, is performed for patients with carcinomatous meningitis; however, it is rarely successful. Ventriculoperitoneal shunting(V-P shunt)is a surgical intervention that might relieve the pain temporarily and improve the quality of life. VPS should be taken into consideration in line with patients' and their families' intentions since the overall survival is fairly short.

[Effect of Endoscopic Resection on Prognosis in T1b Colorectal Cancer]

With the advancement of endoscopic resection(ER)of colorectal cancer, surgical resection after ER has been increasing. This study evaluated the effects of initial ER on short- and long-term outcomes in T1b colorectal cancer. This retrospective cohort study enrolled patients with pathological T1b colorectal cancer who underwent colorectal surgical resection between 2008 and 2018. A total of 239 eligible patients were divided into 2 groups: patients initially treated using surgical resection with lymph node dissection(LND)(surgery alone, n=142)and patients treated using initial ER and additional surgical resection with LND(surgery after ER, n=97). No significant differences were observed in short-term outcomes(ie, operative time, blood loss, or postoperative complications)or the long-term outcomes(ie, recurrence rate, overall survival rate, or recurrence free survival rate)between groups.

Circulating MicroRNAs in Gastrointestinal Cancer

Simple Summary

The screening methods and therapeutic strategies for gastrointestinal cancer (GIC) have improved, but mortality in GIC patients remains high. Early detection and precise evaluation of GIC are required to further improve treatment outcomes in GIC patients. MicroRNAs (miRNAs), which do not encode proteins, have attracted attention as biomarkers of various diseases. Since the first report revealing the strong correlation between miRNAs and cancer in 2002, numerous studies have illustrated the changes in the expression and the biological and oncological effects of miRNAs in GIC. Furthermore, miRNAs circulating in the blood are reported to be associated with GIC status. These miRNAs are thought to be useful as noninvasive biomarkers because of their stability in blood. Herein, we discuss the potential of miRNAs as noninvasive biomarkers for each type of GIC on the basis of previous reports and describe perspectives for their future application.

Abstract

Gastrointestinal cancer (GIC) is a common disease and is considered to be the leading cause of cancer-related death worldwide; thus, new diagnostic and therapeutic strategies for GIC are urgently required. Noncoding RNAs (ncRNAs) are functional RNAs that are transcribed from the genome but do not encode proteins. MicroRNAs (miRNAs) are short ncRNAs that are reported to function as both oncogenes and tumor suppressors. Moreover, several miRNA-based drugs are currently proceeding to clinical trials for various diseases, including cancer. In recent years, the stability of circulating miRNAs in blood has been demonstrated. This is of interest because these miRNAs could be potential noninvasive biomarkers of cancer. In this review, we focus on circulating miRNAs associated with GIC and discuss their potential as novel biomarkers.

Frequency shift algorithm: Design of a baseband phase locked loop for frequency-domain multiplexing readout of x-ray transition-edge sensor microcalorimeters

The Transition-Edge Sensor (TES) is an extremely sensitive device, which is used to measure the energy of individual x-ray photons. For astronomical spectrometry applications, SRON develops a frequency domain multiplexing readout system for kilopixel arrays of such TESs. Each TES is voltage biased at a specific frequency in the range of 1-5 MHz. Isolation between the individual pixels is obtained through very narrow-band (high-Q) lithographic LC resonators. To prevent energy resolution degradation due to intermodulation line noise, the bias frequencies are distributed on a regular grid. The requirements on the accuracy of the LC resonance frequency are very high. The deviation of the resonance frequencies due to production tolerances is significant with respect to the bandwidth, and a controller is necessary to compensate for the LC series impedance. We present two such controllers: a simple orthogonal proportional-integral controller and a more complex impedance estimator. Both controllers operate in baseband and try to make the TES current in-phase with the bias voltage, effectively operating as phase-locked loops. They allow off-LC-resonance operation of the TES pixels while preserving the TES thermal response and energy resolution. Extensive experimental results-published in a companion paper recently-with the proposed methods show that these controllers allow the preservation of single pixel energy resolution in multiplexed operation.

Analysis of semicircular canal function as evaluated by video Head Impulse Test in patients with vestibular schwannoma

OBJECTIVE

The aim of the present study was to investigate the factors influencing semicircular canal function as evaluated by video Head Impulse Test (vHIT) in patients with vestibular schwannoma.

METHODS

Twenty-four patients with untreated vestibular schwannoma underwent vHIT examination. The correlations between semicircular canal function and factors including age, tumor size, disease duration and hearing loss were evaluated.

RESULTS

The functions of all three semicircular canals on the affected side evaluated by vHIT were significantly lower than those on the unaffected side. Although there were no significant correlations between semicircular canal function and age, tumor size or disease duration, a negative significant correlation between vestibulo-ocular reflex (VOR) gain as evaluated by vHIT and hearing loss was observed.

CONCLUSIONS

From the results of the relationship between hearing loss and VOR gain, the damage to the audio and vestibular systems in patients with VS may be correlated. As it has been suggested that tumor size was not a significant factor in the VOR gain evaluated by vHIT, multifactorial causes rather than the simple compression of the vestibular nerves alone may be related to the dysfunction of the semicircular canals in patients with vestibular schwannoma.

Risk Factors for Lymph Node Metastasis in Pathological T1b Colorectal Cancer

BACKGROUND/AIM

The rate of lymph node metastasis (LNM) of colorectal carcinoma (CRC) with a submucosal (SM) invasion depth of 1000 µm or more can reach 12.5%, which is the most common reason for additional resection in daily practice. Other studies have reported that the rate of LNM is less than 2%, regardless of the depth of invasion, if the lesions show good histology, lymphovascular infiltration is negative, and tumor budding is limited. The purpose of this study was to investigate new risk factors for LNM in T1b colorectal cancer.

PATIENTS AND METHODS

The 239 patients who were diagnosed with pathological T1b CRC after colorectal surgical resection at the Osaka Police Hospital in Japan between January 2008 and December 2018 were retrospectively reviewed in this study.

RESULTS

The LNM rate was 11.3% (27/239). The variables identified as being significant factors using multivariate analysis were: i) lymphatic invasion (Ly)-positive [odds ratio (OR)=5.97; 95% confidence interval (CI)=2.27-15.74], ii) female gender (OR=3.49; 95%CI=1.38-8.85), and iii) left-sided colorectal involvement (OR=4.98; 95%CI=1.22-20.39). If none of these risk factors were present with T1b, the LNM rate was 0% (0/28).

CONCLUSIONS

Ly-positive, female gender, and left-sided colorectal involvement could be risk factors for LNM in T1b CRC.

Nivolumab with carboplatin, paclitaxel, and bevacizumab for first-line treatment of advanced nonsquamous non-small-cell lung cancer

BACKGROUND

This international, randomized, double-blind phase III study (ONO-4538-52/TASUKI-52) evaluated nivolumab with bevacizumab and cytotoxic chemotherapy as first-line treatment for nonsquamous non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Between June 2017 and July 2019, this study enrolled treatment-naïve patients with stage IIIB/IV or recurrent nonsquamous NSCLC without sensitizing EGFR, ALK, or ROS1 alterations. They were randomly assigned in a 1 : 1 ratio to receive nivolumab or placebo in combination with carboplatin, paclitaxel, and bevacizumab every 3 weeks for up to six cycles, followed by nivolumab/placebo with bevacizumab until progressive disease or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) assessed by an independent radiology review committee (IRRC).

RESULTS

Overall, 550 patients from Japan, Korea, and Taiwan were randomized; of these patients, 273 and 275 received the nivolumab and placebo combinations, respectively. In the present preplanned interim analysis with a median follow up of 13.7 months, the IRRC-assessed median PFS was significantly longer in the nivolumab arm than in the placebo arm (12.1 versus 8.1 months; hazard ratio 0.56; 96.4% confidence interval 0.43-0.71; P < 0.0001). The PFS benefit was observed across all patients with any programmed death-ligand 1 (PD-L1) expression levels including PD-L1-negative patients. The IRRC-assessed objective response rates were 61.5% and 50.5% in the nivolumab and placebo arms, respectively. The incidence of treatment-related adverse events of grade 3 or 4 was comparable between the two arms; treatment-related adverse events leading to death were observed in five and four patients in the nivolumab and placebo arms, respectively.

CONCLUSION

The TASUKI-52 regimen should be considered a viable new treatment strategy for treatment-naïve patients with advanced nonsquamous NSCLC.

Long-term outcomes of single-incision versus multiport laparoscopic totally extra-peritoneal inguinal hernia repair: a single-institution experience of 186 consecutive cases

PURPOSE

This retrospective study was conducted to compare the long-term outcomes of single-incision totally extraperitoneal (S-TEP) inguinal hernia repair and conventional multiport totally extraperitoneal (M-TEP) inguinal hernia repair.

METHODS

The study population included 186 consecutive patients (S-TEP, n = 149; M-TEP, n = 37) who underwent elective surgery for inguinal hernia at Osaka Police Hospital between 2011 and 2013.

RESULTS

No significant between-group difference was found in patient or hernia characteristics or in perioperative outcomes, with the exception of age (S-TEP group vs. M-TEP group: median 69 [IQR 60-75] years vs. 64 [55-69] years, respectively; P = 0.019). Furthermore, no significant between-group difference was found in follow-up time (5.5 [3.0-5.8] vs. 5.4 [3.1-5.7] years, P = 0.839), recurrence rate (0.6 vs. 2.4%, P = 0.358), chronic pain (1.2 vs. 0%, P = 1.000), feeling the mesh (2.3 vs. 7.1%, P = 0.142), or movement limitation (0.6 vs. 0%, P = 1.000). All chronic symptoms were "mild but not bothersome." A metachronous contralateral inguinal hernia developed in 8.1% of patients.

CONCLUSION

The long-term outcomes of S-TEP repair were comparable to those of M-TEP, with rates of recurrence, chronic pain, feeling the mesh, and movement limitation falling within acceptable limits.

Effectiveness of frailty screening and perioperative team management of colectomy patients aged 80 years or more

BACKGROUND

We aimed to clarify usefulness of the modified Frailty Index 11 (mFI-11) for assessing risk of postoperative complications (POCs) and effectiveness of perioperative management team (POMT) intervention for improving postoperative status of frail aged patients requiring colorectal cancer (CRC) surgery.

METHODS

We compared, retrospectively, surgical outcomes among 151 consecutive CRC surgery patients aged ≥80 years. Patients were grouped by mFI-11 scores and by POMT intervention (vs. no POMT intervention).

RESULTS

POCs were more prevalent, postoperative stays were longer, and discharge status was poorer among high-risk (mFI-11 ≥ 3/11) patients without POMT intervention than among low-risk (mFI-11 ≤ 2/11) patients (p = 0.04, p = 0.02, p < 0.01). Multiple POCs occurred less frequently and performance of activities of daily living was better for high-risk patients with (vs. those without) POMT intervention (p = 0.04, p = 0.03).

CONCLUSION

POMT intervention appears beneficial for frail aged patients scheduled for CRC surgery.

Administration Method of Adjuvant Tegafur-Uracil and Leucovorin Calcium in Patients with Resected Colorectal Cancer: A Phase III Study

LESSONS LEARNED

The 3-year disease-free survival rate of the twice-daily regimen was not inferior to that of the conventional three-times-daily regimen, and the twice-daily regimen did not lead to an increase in adverse events. The effectiveness of the twice-daily regimen highlights an increased number of treatment options for patients. This will facilitate personalized medicine, particularly for elderly or frail patients who may experience more severe side effects from the combination therapy.

BACKGROUND

Tegafur-uracil (UFT)/leucovorin calcium (LV) is an adjuvant chemotherapy treatment for colorectal cancer. We conducted a multicenter randomized trial to assess the noninferiority of a twice-daily compared with a three-times-daily UFT/LV regimen for stage II/III colorectal cancer in an adjuvant setting.

METHODS

Patients were randomly assigned to group A (three doses of UFT [300 mg/m² per day]/LV [75 mg per day]) or B (two doses of UFT [300 mg/m² per day]/LV [50 mg per day]). The primary endpoint was 3-year disease-free survival.

RESULTS

In total, 386 patients were enrolled between July 28, 2011, and September 27, 2013. The 3-year disease-free survival rates of group A (n = 194) and B (n = 192) were 79.4% and 81.4% (95% confidence interval, 72.6-84.4-74.5-85.9), respectively. The most common grade 3/4 adverse events in group A and B were diarrhea (3.9% vs. 7.3%), neutropenia (2.9% vs. 1.6%), increase in aspartate aminotransferase (4.0% vs. 3.9%), increase in alanine aminotransferase (6.2% vs. 6.8%), nausea (1.7% vs. 3.4%), and fatigue (1.1% vs. 2.3%).

CONCLUSION

Group B outcomes were not inferior to group A outcomes, and adverse events did not increase.

Frequency shift algorithm: Application to a frequency-domain multiplexing readout of x-ray transition-edge sensor microcalorimeters

In the frequency-domain multiplexing (FDM) scheme, transition-edge sensors (TESs) are individually coupled to superconducting LC filters and AC biased at MHz frequencies through a common readout line. To make efficient use of the available readout bandwidth and to minimize the effect of non-linearities, the LC resonators are usually designed to be on a regular grid. The lithographic processes, however, pose a limit on the accuracy of the effective filter resonance frequencies. Off-resonance bias carriers could be used to suppress the impact of intermodulation distortions, which, nonetheless, would significantly affect the effective bias circuit and the detector spectral performance. In this paper, we present a frequency shift algorithm (FSA) to allow off-resonance readout of TESs, while preserving the on-resonance bias circuit and spectral performance, demonstrating its application to the FDM readout of an x-ray TES microcalorimeter array. We discuss the benefits in terms of mitigation of the impact of intermodulation distortions at the cost of increased bias voltage and the scalability of the algorithm to multi-pixel FDM readout. We show that with FSA, in the multi-pixel and frequencies shifted on-grid, the line noises due to intermodulation distortion are placed away from the sensitive region in the TES response and the x-ray performance is consistent with the single-pixel, on-resonance level.

Long-term outcomes of single-incision versus multiport laparoscopic colectomy for colon cancer: results of a propensity score-based analysis

BACKGROUND

Long-term outcomes of single-incision laparoscopic colectomy (SILC) for colon cancer (CC), as practiced in real-world settings, especially in relation to disease stage, have not been established. We examined, retrospectively, both short- and long-term outcomes of SILC versus those of multiport laparoscopic colectomy (MPLC) performed for CC in a propensity-score-matched cohort.

METHODS

The study involved 263 patient pairs matched 1:1 from among 691 patients who, between January 2008 and May 2014, underwent either SILC or MPLC for a primary solitary CC at our hospital. Short-term and long-term operative outcomes were compared between the two groups.

RESULTS

Operation time was the only surgical outcome that varied significantly between the two groups (p = 0.0004). Overall 5-year cancer-specific survival (CSS) in the SILC group was 93.7 (95% CI 89.6-96.2)%, and CSS per pathological stage (I, II and III) was 98.5 (90.0-99.8)%, 96.0 (88.2-98.7)%, and 88.3 (79.6-93.6)%, respectively, whereas overall 5-year CSS in the MPLC group was 93.3 (89.4-95.9)%, and CSS per pathological stage was 100%, 95.4 (88.3-98.3)%, and 84.1 (74.1-90.8)% (p = 0.5278, 0.2679, 0.7666, and 0.9073), respectively. Overall 3-year disease-free survival (DFS) in the SILC group was 94.0 (90.2-96.4)%, and 3-year DFS per pathological stage was 98.6 (90.4-99.8)%, 90.1 (81.4-95.0)%, and 79.0 (69.4-86.2)%, respectively, whereas overall 3-year DFS in the MPLC group was 93.2 (89.4-95.7)%, and 3-year DFS per pathological disease stage was 100%, 94.5 (87.4-97.7)% and 75.5 (64.7-83.8)% (p = 0.2829, 0.7401, 0.4335 and 0.8518), respectively. Thus, oncological outcomes did not differ significantly between groups. Incisional hernia occurred in 21 (8.0%) SILC group patients and 17 (6.5%) MPLC group patients, without a significant between-group difference (p = 0.6139).

CONCLUSION

Our data indicate that perioperative and oncological outcomes of SILC performed for CC are comparable to those of MPLC performed for CC.

Performance and uniformity of a kilo-pixel array of Ti/Au transition-edge sensor microcalorimeters

Uniform large transition-edge sensor (TES) arrays are fundamental for the next generation of x-ray space observatories. These arrays are required to achieve an energy resolution ΔE < 3 eV full width at half maximum (FWHM) in the soft x-ray energy range. We are currently developing x-ray microcalorimeter arrays for use in the future laboratory and space-based x-ray astrophysics experiments and ground-based spectrometers. In this contribution, we report on the development and the characterization of a uniform 32 × 32 pixel array with 140 × 30 μm² Ti/Au TESs with the Au x-ray absorber. We report on extensive measurements on 60 pixels in order to show the uniformity of our large TES array. The averaged critical temperature is T_c = 89.5 ± 0.5 mK, and the variation across the array (∼1 cm) is less than 1.5 mK. We found a large region of detector's bias points between 20% and 40% of the normal-state resistance where the energy resolution is constantly lower than 3 eV. In particular, results show a summed x-ray spectral resolution ΔE_FWHM = 2.50 ± 0.04 eV at a photon energy of 5.9 keV, measured in a single-pixel mode using a frequency domain multiplexing readout system developed at SRON/VTT at bias frequencies ranging from 1 MHz to 5 MHz. Moreover, we compare the logarithmic resistance sensitivity with respect to temperature and current (α and β, respectively) and their correlation with the detector's noise parameter M, showing a homogeneous behavior for all the measured pixels in the array.

[Case Series of the TAS-102 plus Bevacizumab(Bev)Combination Therapy in Unresectable Advanced Colorectal Cancer]

A phase-Ⅱtrial of TAS-102 plus bevacizumab(Bev)combination therapy showed a progression-free survival(PFS)of 3.7-4.6 months. Here, we report 12 cases of unresectable advanced recurrent colorectal cancer treated with TAS-102 plus Bev therapy at our hospital between June 2017 and February 2020. The median PFS was 6 months(2-12). Adverse events greater than Grade 3 were neutropenia(33.3%), febrile neutropenia(8.3%), thrombocytopenia(8.3%), and vomiting (8.3%). The frequency of non-hematotoxicity was low. In conclusion, the TAS-102 plus Bev therapy may be a useful option for the late-line treatment of unresectable advanced recurrent colorectal cancer.

[Nodular Lymphocyte-Predominant Hodgkin Lymphoma(NLPHL)Which Originate from the Mesentery-A Series of Two Cases]

Nodular lymphocyte-predominant Hodgkin lymphoma(NLPHL)is a subtype of Hodgkin lymphoma. It is uncommon in Japan, and only a few cases of NLPHL originating from the mesentery have been reported. Most patients with NLPHL present in the early stage, but some patients have malignancy at initial presentation. We should perform staging laparotomy for the diagnosis and treatment of cases in which a lymph node biopsy is difficult.

[Launching Robot-Assisted Laparoscopic Surgery for Rectal Cancer in Our Hospital-Short-Term Results]

Robot-assisted laparoscopic surgery(RALS)for rectal cancer has been covered by National Health Insurance in Japan since April 2018. We launched RALS in our hospital in October 2019 and now report the short-term results(up to January 2020). Altogether, 15 consecutive patients(12 men, 3 women: median age 70 years)with rectal cancer underwent RALS during that period. For the first 2 cases, we performed RALS under the instruction of an experienced proctor from another institution. Among the 15 patients, 6 underwent high anterior resection and 9 low anterior resection. Median operating time was 358 min, median intraoperative blood loss was 0 mL, and there were no apparent intraoperative complications. Median postoperative length of hospital stay was 13 days, and only 1 patient developed a high-grade complication(Clavien-Dindo Grade Ⅲb)postoperatively. Hence, RALS for rectal cancer was launched successfully in our institution.

[A Case of Slow-Growing Intrahepatic Cholangiocarcinoma after Resection of Gastric Cancer]

An 83-year-old woman was given a diagnosis of gastric cancer and received distal gastrectomy 9 years ago. Three years later, CT revealed a tumor measuring 13 mm in diameter in hepatic segment 7. She was followed for 5 years, and the size of the tumor did not change. Eight years later after gastrectomy, the tumor size slightly enlarged to 17 mm, and biopsy revealed adenocarcinoma. The patient underwent liver resection of segment 7. The pathological diagnosis was well differentiated intrahepatic cholangiocarcinoma(ICC). No sign of recurrence has been found during a 1-year. This case, in which the patient was followed for 5 years before curative surgical treatment, is significant, because it demonstrates the slow-growing nature of ICC.

Abstract 264: Long noncoding RNA LNC01534 regulates cancer stem cells in colorectal cancer

Introduction The clinical importance of cancer stem cells (CSCs) has been widely reported, and clinical studies targeting CSCs are in progress. Additionally, accumulating evidence suggests that long noncoding RNAs (lncRNAs) have essential roles in cancer initiation and progression, while deregulated lncRNA expression is found in a variety of cancer types. In this study, we focused on lncRNAs regulating CSCs in colorectal cancer (CRC).

Objectives To identify the lncRNAs associated with CSCs and to evaluate their clinical relevance and function.

Materials and Methods We separated CSCs and other cells in CRC using the ornithine decarboxylase (ODC) degron system to visualize CSCs based on the correlation between low proteasome activity and CSC properties. We performed comprehensive gene analysis comparing CSCs and other cells to identify a candidate lncRNA that regulates the stemness of CRC cells. Finally, we analyzed the clinical relevance and function of the lncRNA.

Results The lncRNA LNC01534 showed high expression in CSCs compared with the level in other CRC cells. Using gene expression and clinical data from the Cancer Genome Atlas Project for CRC patients, we showed that LNC01534 was associated with overall survival in CRC. LNC01534 was also associated with overall survival and disease-free survival in 187 separate CRC samples. Functional studies revealed that the loss of LNC01534 function reduced proliferation and arrested the cell cycle in CRC cells. Furthermore, genes that underwent expression changes upon the knockdown of LNC01534 were evaluated by RNA-seq. This showed that the knockdown of LNC01534 affected the expression of genes related to endoplasmic reticulum (ER) stress and autophagy. Specifically, the expression levels of HSPA5, LC3-I, p62, and Beclin-1–genes related to ER stress and autophagy–increased upon suppressing LNC01534.

Conclusions We demonstrated the clinical and biological relevance of LNC01534 in association with CSCs, and discovered the effect of LNC01534 on ER stress and autophagy to maintain stemness in CRC.

Citation Format: Masahisa Ohtsuka, Wu Xin, Momoko Ichihara, Haruka Hirose, Hidekazu Takahashi, Chu Matsuda, Hiroki Akamatsu, Tsunekazu Mizushima, Yuichiro Doki, Hirofumi Yamamoto. Long noncoding RNA LNC01534 regulates cancer stem cells in colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 264.

Effects of Daikenchuto on postoperative gastrointestinal motility in colorectal carcinoma patients with abdominal pain and distension: a prospective, randomized trial

PURPOSE

To investigate the efficacy and safety of Daikenchuto (DKT) for colorectal cancer patients undergoing surgery with the potential risk of postoperative ileus (POI).

METHODS

Colorectal cancer patients with abdominal pain and distention, scheduled for surgery, were randomly assigned to a DKT group or a control group. Patients assigned to the DKT group were given 15 g of DKT per day during the perioperative period. We then compared the perioperative gastrointestinal symptoms between the two groups.

RESULTS

The aim for a sample size of 30 patients per group was not reached in time, so we conducted an analysis on 16 patients in each group. The visual Analogue Scale scores for abdominal pain and distention were similar in the two groups. The number of bowel movements per day on postoperative days (PODs) 1, 2, and 6 were significantly lower in the DKT group. The incidence of a sensation of incomplete bowel evacuation on PODs 3 and 28 was also significantly lower in the DKT group. There were no adverse events thought to be related to DKT.

CONCLUSIONS

DKT could potentially inhibit diarrhea and reduce the number of bowel movements per day and the sensation of incomplete bowel evacuation after colorectal surgery. Thus, the perioperative use of DKT may be safe for colorectal cancer patients with abdominal pain and distention, who undergo surgery.

Role of single-incision laparoscopic surgery in the management of small bowel obstruction

BACKGROUND

Small bowel obstruction (SBO) arises on various backgrounds, and the surgical procedure is often modified intraoperatively as needed. Single-incision laparoscopic surgery (SILS) is less invasive than conventional multiport laparoscopic surgery (MPS) and reported to be equally safe and efficient. We have been applying SILS to SBO requiring surgical treatment, and we conducted a retrospective study to clarify the role of SILS in the management of SBO.

METHODS

Thirty-four consecutive patients were identified for inclusion in the study through a review of hospital records of patients having undergone surgery for SBO between May 2013 and June 2018. Patients with tumor- or hernia-related SBO were excluded. We also identified, for comparison, a group of patients who had undergone open surgery for SBO during the preceeding 5-year period. The primary study endpoint was the SILS completion rate, and analyses were performed to identify risk factors for conversion to open surgery and perioperative complications.

RESULTS

The SILS completion rate was 70.6% (24/34 patients), with conversion open surgery required for the remaining 10 (29.4%) patients. Conversion was necessitated by limited working space in 5 (50%) patients, discovery of massive necrosis in 3 (30%), and non-detection of the responsible lesion in 2 (20%). Univariable analysis showed an American Society of Anesthesiologists Physical Status score (p = 0.020) and severe intra-abdominal adhesions (p = 0.007) to be risk factors for conversion. Conversion to open surgery (vs complete SILS) was significantly associated with increased operation time (p = 0.018), blood loss (p = 0.021), postoperative stay (p = 0.010), and postoperative complications (p = 0.004). Open surgery was significantly associated with increased postoperative stay (p = 0.026) and postoperative complications (p = 0.011).

CONCLUSION

SILS appears to be a reasonable surgical treatment option for selected patients with SBO.

Surgical Resection of Colorectal Cancer With Distant Metastases to Other than Liver or Lung

BACKGROUND/AIM

If both distant metastases and the primary tumour of colorectal cancer (CRC) are resectable, resection of the distant metastases is considered. The aim of this retrospective study was to determine the efficacy of curative resection of both primary and metastatic lesions in organs other than liver or lung in CRC patients.

PATIENTS AND METHODS

The medical records of 23 CRC patients who received R0 resection for primary and metastatic regions between 2009 and 2018 were retrospectively analyzed.

RESULTS

The 3-year overall survival (OS) in all 23 cases was 80.0%. There was no clinicopathological factor associated with OS on univariate analysis.

CONCLUSION

Curative surgical resection appears to be useful for distant CRC metastases to organs other than liver or lung.

DS-Screen: Prospective analysis of the expression status of FGFR2 and HER2 in colorectal and gastric cancer population

431

Background: FGFR2 and HER2 proteins are well-known molecular targets for cancer therapy, and there are emerging attractive protein-targeted agents such as second generation antibody-drug conjugates. However, there are still limited information about the expression status of FGFR2 and HER2 in gastrointestinal cancer and their relationship to patient background with cancer. In this study, expression status of FGFR2 and HER2 in advanced/metastatic gastric cancer (GC) and colorectal cancer (CRC) were prospectively analyzed in clinical setting. Moreover, eligible patients for the clinical trials of DS-1123 or DS-8201, which are FGFR2- or HER2-targeting anti-cancer agent respectively, were screened. Methods: Patients with advanced/metastatic GC, gastroesophageal junctional cancer (GEJ), and CRC were enrolled. Expression status of FGFR2 and HER2 were prospectively analyzed by IHC and/or FISH. Results: A total of 565 patients (GC; 160, GEJ; 16, CRC; 389) have been enrolled in this study from November 2016 to June 2018. FGFR2 expression (IHC 1+~3+) was observed in 24%, 44%, and 3% of GC, GEJ, and CRC respectively. HER2 expression (IHC 2+, 3+) was observed in 24%, 44%, and 17% of GC, GEJ, and CRC respectively. Expression levels of FGFR2 and HER2 seemed to be not correlated with each other in all 3 types of cancer. Distributions of expression level of FGFR2 or HER2 were slightly different among the histological types in GC. In CRC, distribution of HER2 expression level was also slightly different among the histological types and HER2 expression level was higher in KRAS/NRAS wild type compared to KRAS/NRAS mutant. There was no association between HER2 expression level and primary tumor sites in patients with CRC. Slight concordance of HER2 expression was observed between IHC and FISH in CRC. A total of 7 patients have been enrolled in clinical trials of DS-1123 or DS-8201 through this study based on the analysis findings. Conclusions: This study showed insights into the expression status of FGFR2 and HER2 in GC and CRC as a large-scale prospective analysis. Seven patients who had no standard therapy could access exploratory new drug based on targetable agents through this study. Clinical trial information: 163380.

[A Case of Complete Pathological Response in a Patient with Advanced Ascending Colon Cancer That Invaded the Liver and Duodenum after FOLFOXIRI plus Bevacizumab Chemotherapy]

A 71-year-old woman with advanced ascending colon cancer was admitted to our hospital. Abdominal computed tomography( CT)revealed locally advanced sigmoid colon cancer with suspected invasion of the liver and duodenum. The clinical stage of the disease was cT4bN3M1a, cStage Ⅳa, with wild-type RAS and UGT1A1 expression. An ileostomy was performed because of bowel obstruction. The patient received 6 courses of FOLFOXIRI plus bevacizumab(Bev). The only adverse event was Grade 3 neutropenia. Laparoscopic right hemicolectomy with lymph node dissection was performed. The pathological diagnosis was the absence of viable, Grade 3 carcinoma cells. This result suggested that preoperative FOLFOXIRI plus Bev chemotherapy is useful for the treatment of locally advanced colon cancer.

[Single-Incision Laparoscopic Colectomy for Descending Colon Cancer in a Patient with a Horseshoe Kidney]

A 67-year-old woman presented with bloody stools to a local physician. Lower gastrointestinal endoscopy revealed a type 3 all-circumferential tumor at descending colon. She was diagnosed with descending colon cancer and referred to our hospital for surgery. Preoperative computed tomography(CT)revealed a horseshoe kidney. We performed single-incision laparoscopic colectomy for descending colon cancer(cT3cN0cM0, cStageⅡa)complicated by a horseshoe kidney. The surgery was performed safely without any additional injuries. In patients with horseshoe kidneys, abnormalities have been reported in the running of the blood vascular system and the renal pelvis and ureter systems. Thus, sufficient understanding of the anatomic abnormality by preoperative examinations, such as 3D-CT, is essential for performing surgery safely.

[A Case of Multidisciplinary Treatment for a Recurrent Gastrointestinal Stromal Tumor of the Stomach]

The standard treatment for unresectable or recurrent gastrointestinal stromal tumor(GIST)is tyrosine kinase inhibitor(TKI). It is reported that resection of metastatic lesions after TKI administration prolongs progression free survival, but its influence on overall survival is not clarified. We experienced a case of GIST with peritoneal dissemination for which TKI administration and 2 local resections were effective. The patient was a man in his 70's. We started chemotherapy with imatinib for GIST with peritoneal dissemination. However, it was discontinued due to the occurrence of interstitial pneumonia. Dissemination was evaluated as radically resectable on the images. After the interstitial pneumonia was alleviated, surgery was performed. Although sunitinib was introduced at 2 months postoperatively, recurrent peritoneal dissemination was detected at 32 months postoperatively, and treatment was then changed to regorafenib. Regorafenib treatment reduced the tumor size; however, Grade 3 albuminuria was detected 16 months after treatment initiation and, thus, this treatment was discontinued. Subsequently, the tumor enlarged again. Because there was only 1 recurrent lesion, we performed radical resection. Postoperatively, a reduced dose of regorafenib was re-administered. At present, 9 months after the re-surgery, the patient is alive without recurrence.

[A Case of Primary Duodenal Adenocarcinoma in the Fourth Portion]

A 66-year-old woman admitted for nausea was found to have a type 2 tumor with stenosis at the fourth portion of the duodenum by upper gastrointestinal series and endoscopy, which was diagnosed as an adenocarcinoma by endoscopic biopsy. Abdominal computed tomography(CT)showed an irregular thick wall at the fourth portion of the duodenum but without metastasis or invasion to the adjacent vessels. We examined the lymph nodes around the pancreatic head intraoperatively and partially resected the duodenum and jejunum based on the diagnosis of negative swollen nodes. The definitive diagnosis was primary tubular adenocarcinoma of the fourth portion of the duodenum, T3, N0, M0, Stage ⅡA. Reports of primary cancer of the fourth portion of the duodenum are very rare, and we include a discussion of the current literature.

c-Src promotes tumor progression through downregulation of microRNA-129-1-3p

MicroRNAs (miRNAs) fine‐tune cellular signaling by regulating expression of signaling proteins, and aberrant expression of miRNAs is observed in many cancers. The tyrosine kinase c‐Src is upregulated in various human cancers, but the molecular mechanisms underlying c‐Src‐mediated tumor progression remain unclear. In previous investigations of miRNA‐mediated control of c‐Src‐related oncogenic pathways, we identified miRNAs that were downregulated in association with c‐Src transformation and uncovered the signaling networks by predicting their target genes, which might act cooperatively to control tumor progression. Here, to further elucidate the process of cell transformation driven by c‐Src, we analyzed the expression profiles of miRNAs in a doxycycline‐inducible Src expression system. We found that miRNA (miR)‐129‐1‐3p was downregulated in the early phase of c‐Src‐induced cell transformation, and that reexpression of miR‐129‐1‐3p disrupted c‐Src‐induced cell transformation. In addition, miR‐129‐1‐3p downregulation was tightly associated with tumor progression in human colon cancer cells/tissues. Expression of miR‐129‐1‐3p in human colon cancer cells caused morphological changes and suppressed tumor growth, cell adhesion, and invasion. We also identified c‐Src and its critical substrate Fer, and c‐Yes, a member of the Src family of kinases, as novel targets of miR‐129‐1‐3p. Furthermore, we found that miR‐129‐1‐3p‐mediated regulation of c‐Src/Fer and c‐Yes is important for controlling cell adhesion and invasion. Downregulation of miR‐129‐1‐3p by early activation of c‐Src increases expression of these target genes and synergistically promotes c‐Src‐related oncogenic signaling. Thus, c‐Src‐miR‐129‐1‐3p circuits serve as critical triggers for tumor progression in many human cancers that harbor upregulation of c‐Src.

[A Case of Mesenteric Hematoma Caused by Abdominal Metastasis of Small Cell Lung Carcinoma]

Chemoradiation was performed at Osaka Police Hospital's department of respiratory medicine on a 70-year-old male with small cell lung carcinoma(cT4N3M0, cStage ⅢC). Subsequent to secondary chemotherapy for multiple bone metastases that had been observed, he received care to control the disease. He arrived at the hospital complaining of epigastric pain. He got CT-scan and was referred to our department because of a suspected hematoma around the right gastroepiploic artery. He was treated conservatively because circulatory dynamics were steady and there was no indication that anemia had progressed. However, when a test laparotomy was performed the day after the start of treatment because he presented with decreased blood pressure and progressive anemia, a massive hematoma was found around the right gastroepiploic artery. The hematoma was removed, and hemostasis was performed. Based on the pathological findings of the excised specimen, he was diagnosed with abdominal metastasis of small cell lung carcinoma. This is a report on our experience and a literature review on a case of mesenteric hematoma caused by abdominal metastasis of small cell lung carcinoma.

[A Case of Retroperitoneal Dedifferentiation Type Liposarcoma in Which Total Pancreatectomy and Radiation Therapy Was Performed at the Remnant Pancreas after Pancreaticoduodenectomy]

A 75-year-old man presented with a fever. Computed tomography revealed a 10 cm solid tumor under the duodenum. A pre-operative diagnosis of liposarcoma was established using biopsy. Pancreaticoduodenectomy was performed, and the pathological examination led to the diagnosis of dedifferentiation type liposarcoma. Two years later, the liposarcoma recurred at the remnant pancreas. A total remnant pancreatectomy was performed. The pathological examination revealed dedifferentiated type liposarcoma and positive surgical margins. Therefore, radiotherapy of 59.4 Gy in 33 fractions was performed at the recurrence area. The patient has been recurrence-free from 1 year 6 months since the second operation.

Metachronous rectal metastasis from pulmonary adenocarcinoma after 11 years of chemo-, immuno-, and radiotherapy for recurrent lesions: a case report

Background

Rectal metastasis from pulmonary adenocarcinoma is rare, and it has been regarded as an end-stage phenomenon. Recently, however, advances in lung cancer treatment have improved the chance of long-term survival of patients with unresectable distant metastases. We describe the occurrence and management of metastatic spread of a pulmonary carcinoma to the rectum.

Case presentation

The patient was a 79-year-old woman who had undergone thoracoscopic left lobectomy for pulmonary adenocarcinoma and then, over the next 11 years, various drugs (carboplatin + paclitaxel (as adjuvant therapy), gefitinib, gemcitabine + vinorelbine, S1 (an oral 5-fluorouracil-based drug), carboplatin + pemetrexed + bevacizumab, erlotinib, nivolumab, afatinib, and carboplatin+ S1) were administered, especially for hilar and mediastinal lymph node recurrences. During the eleventh postoperative year, left and right iliac bone metastases were detected, and radiation therapy was undertaken for local control of these lesions. When ¹⁸F-fluorodeoxyglucose positron emission tomography was performed for evaluation of the disease, tracer accumulation in the upper rectum was seen. Colonoscopic examination of the rectum revealed an intramural mass with central ulceration, and the mass was diagnosed histologically as an adenocarcinoma. The bone metastases appeared to be controlled, and the patient’s performance status was good, but she had suffered constipation for about a year and desired treatment. Thus, laparoscopic low anterior resection was performed. Histopathologic analysis revealed a moderately differentiated adenocarcinoma existing mainly between the submucosa and serosa, and immunohistochemical analysis showed the tumor to be positive for cytokeratin (CK) 7, negative for CK20, positive for thyroid transcription factor-1, and negative for special AT-rich sequence-binding protein 2 and caudal type homeobox 2, confirming the diagnosis of rectal metastasis from the primary pulmonary adenocarcinoma. The patient recovered well without any change in her functional status. Systemic chemotherapy was resumed, and she continues to do well, now 6 months after surgery.

Conclusions

Surgery may be a good option for the management of an isolated rectal metastasis from pulmonary cancer in patients whose functional status is good.

Abstract 401: Clinical impact of viable circulating tumor cells (v-CTC) detection and PD-L1 expression on v-CTC in the patients with resectable pancreatic cancer

[Introduction] The capture and analysis of CTCs as “liquid biopsy” provides the possibility to avoid invasive biopsies, obvious implications in cancer diagnosis and staging. We tested novel methods for viable CTCs (v-CTC) isolation in the patients (pts) with pancreatic cancer (PC), and investigated the clinical potential of v-CTCs in prognosis. We analyzed the PD-L1(L1) expression in both PC tumors and v-CTCs.

[Pts and Methods] 7.5 ml of venous blood was collected prospectively from 39 PC pts, either surgery first (S group) or pre-treatment, consisted of Gem:800mg/m2; and S-1:80mg/m2 given concurrently with IMRT to 60Gy (NACRT:N group). To detect v-CTCs, we employed a telomerase-specific replication-selective adenovirous expressing GFP. For S group, samples were obtained before/after resection. For N group, samples were obtained before/after NACRT and after resection. To distinguish between leucocyte and cells with either epithelial or mesenchymal origin, cells were stained by anti-CD45, anti-Cytokeratin and anti-Vimentin Abs. GFP-positive and CD45-negative cells were counted as v-CTC. To assess L1 expression in PC tissues (IHC) and v-CTCs, L1 IHC kit (22C3, for tissues) and anti-human L1 mAb(MIH1,for CTCs) were employed.

[Results]S group: 24 pts aged 53~85 years (male/female=12/12) were enrolled. 24 pts underwent curative resection. No v-CTCs were detected in 6 pts at both before and after resection, and 5 of 6 pts survived without recurrence. V-CTCs were identified in 18 of 24 pts, and 13 of 18 pts developed liver metastasis. Marked decrease of CTC counts were seen after resection in 10 of 18 pts, but 9 pts developed recurrence. N group: 15 PC pts aged 44~77 years (male/female=4/11) were enrolled. 15 pts underwent curative resection. No v-CTCs were detected in 5 pts, and 5 pts survived without recurrence. V-CTCs was identified in 10 of 15 pts, and only 3 out of 10 pts developed disease recurrence. Marked increase in CTC counts was observed after NACRT in 5 of 6 CTC-positive pts before NACRT, and 3 of 5 pts developed liver metastasis and died. NACRT may induce tumor cell dissemination into the blood circulation for CTC-positive pts. PD-L1 expression: L1 expression were assessed for 21 pts (S group:18, N group: 3). No patients with IHC-L1 high expression (≥50%) were observed (&lt;1% [negative]:9, 10%:6, 20%:4, 40%:2). For S group, IHC-L1 low +/CTC-L1 + were detected in 12/18 pts (66%). IHC-L1-/CTC-L1+ were detected in 3/18 pts (17%). IHC-L1 - /no detectable CTCs were detected in 3/18 pts (17%). For N group, IHC-L1 - were detected in 3 pts, but CTCs-L1 + were detected in 2 pts (1 pt had no CTCs). The majority of detectable v-CTCs were positive for L1-expression (89% [92/103 CTCs]), despite L1-negative or -low expression in PC tissues.

[Conclusions] Viable CTC detection appears as a promising prognostic marker. Immunotherapy with anti-PD-1/PD-L1 Abs may effectively target v-CTCs.

Note: This abstract was not presented at the meeting.

Citation Format: Masahiro Tanemura, Kenta Furukawa, Manabu Mikamori, Takurou Saito, Masahisa Otsuka, Yozo Suzuki, Kentaro Kishi, Hironao Yasuoka, Masahiko Tsujimoto, Yasuo Urata, Hiroki Akamatsu. Clinical impact of viable circulating tumor cells (v-CTC) detection and PD-L1 expression on v-CTC in the patients with resectable pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 401.

A six-degree-of-freedom micro-vibration acoustic isolator for low-temperature radiation detectors based on superconducting transition-edge sensors

Dilution and adiabatic demagnetization refrigerators based on pulse tube cryocoolers are nowadays used in many low temperature physics experiments, such as atomic force and scanning tunneling microscopy, quantum computing, radiation detectors, and many others. A pulse tube refrigerator greatly simplifies the laboratory activities being a cryogen-free system. The major disadvantage of a pulse tube cooler is the high level of mechanical vibrations at the warm and cold interfaces that could substantially affect the performance of very sensitive cryogenic instruments. In this paper, we describe the performance of a very simple mechanical attenuation system used to eliminate the pulse-tube-induced low frequency noise of the superconducting transition-edge sensors under development for the instruments of the next generation of infra-red and X-ray space observatories.

[A Case of Myeloid Sarcoma That Primarily Developed in the Spleen]

We report a case of myeloid sarcoma(MS)that primarily developed in the spleen. The patient was a 60s man with a chief complainant of low-grade fever following a dental implant. Although he underwent intensive antibiotic treatment, including levofloxacin, meropenem, and vancomycin, no significant decline in fever was observed. Abdominal contrast-enhanced CT revealed an LDA occupying the majority of his spleen, which was diagnosed as a splenic abscess. Although a CT-guided biopsy and drainage for the spleen were considered, a puncture of the spleen was not performed due to the substantial concern of bleeding. Subsequently, a splenectomy was performed and HE staining revealed mitosis of tumor cells and massive necrosis. Immunohistochemical analysis revealed that the tumor cells were positive for myeloperoxidase, CD43, CD45, and CD68. Finally, the splenic LDA was diagnosed as MS instead of a splenic abscess. He was treated with systemic chemotherapy. MS primarily develops in the spleen is quite rare: we found only 2 case reports of this disease. The prognosis of MS is poor due to the complications of AML. Accordingly, MS should be considered as a differential diagnosis for accurate diagnosis and treatment of splenic LDA.

[A Case of Cecal Cancer in a Patient with Situs Inversus Treated with Single-Port Laparoscopic Surgery]

A 67-year-old woman who had been treated for cardiac sarcoidosis was diagnosed with cecal cancer by detailed examination. Although an anatomical abnormality was present, we determined that a curative operation with single-port laparoscopic surgery(SILS)was feasible. We safely performed ileocecal resection with D3 lymph node dissection(operative time of 91 min with almost no intraoperative blood loss), and the patient developed no operation-related complications during the postoperative course. Although cecal cancer with situs inversus is very rare, SILS is thought to be safe and feasible when performed by surgeons, who are familiar with the SILS technique and the spatial-cognitive features of situs inversus.

[A Comparative Study on Feasibility of SOX Therapy and SP Therapy with Short Hydration for Gastric Cancer in the Outpatient Setting]

We conducted a retrospective comparative study on feasibility of S-1/oxaliplatin(SOX)therapy and S-1/cisplatin therapy with short hydration(SP-SH)for gastric cancer in the outpatient setting. The subjects were patients with gastric cancer aged younger than 75 years who underwent SOX or SP-SH therapy at our hospital. There were 22 patients in the SOX group and 30 patients in the SP-SH group. Both the groups received the first course during hospitalization and then received the subsequent courses in the outpatient section. Evaluation items for each therapy included the treatment rate in the outpatient setting, number of re-hospitalization cases, relative dose intensity(RDI), and adverse events. The treatment rate in the outpatient setting was 100%(22/22)in the SOX group and 96%in the SP-SH group(26/27). Re-hospitalization cases included 1 case of loss of appetite in the SOX group and 1 cases of loss of appetite and 2 cases of febrile neutropenia(FN)in the SP-SH group. The median values of the RDI were 86% with S-1 and 85% with oxaliplatin in the SOX group and 92% with S-1 and 80% with cisplatin in the SP-SH group. The SP-SH group had a higher proportion of neutropenia cases of Grade 3 or higher(SP-SH 33% v. s SOX 5%, p=0.012). The SOX group showed a higher proportion of loss of appetite cases for all the Grades(SOX 86% v. s SP-SH 50%, p=0.007)and peripheral neuropathy cases(SOX 64% v. s SP-SH 23%, p=0.003). It was considered that SOX and SP-SH therapies can be treated in the outpatient section, although the occurrence of loss of appetite and FN must be considered.