Significance of Adjuvant Chemotherapy for Obstructive Colorectal Cancer After Stent Placement: A Multicenter Retrospective Study

BACKGROUND/AIM

To explore the survival benefit of adjuvant chemotherapy for obstructive colorectal cancer (OCRC) managed by self-expandable metallic stent (SEMS) placement as a bridge to surgery (BTS).

PATIENTS AND METHODS

One hundred twenty-nine patients with pathological stage II/III OCRC who underwent BTS using a SEMS were included in this multicenter retrospective study. Patients were divided into the no-adjuvant chemotherapy group (No-Adj group) (n=52) and adjuvant chemotherapy group (Adj group) (n=77), and relapse-free survival (RFS) was compared.

RESULTS

The No-Adj group had more fragile patient background factors, such as higher age, higher American Society of Anesthesiologists score, and lower preoperative albumin compared with the Adj group. The 3-year RFS rates for the overall cohort were significantly different between the No-Adj and Adj groups (56.4% and 78.5%, respectively; p=0.003). Significant RFS benefits of adjuvant chemotherapy were observed in both pathological stage II and III cancer. Characteristics of more advanced cancer, such as high carcinoembryonic antigen (CEA), pathological T4, and lymphovascular invasion, were associated with survival improvement by adjuvant chemotherapy. T4 and adjuvant chemotherapy were significantly associated with RFS in the multivariate Cox proportional analysis.

CONCLUSION

To our knowledge, this is the first study to show a survival benefit of adjuvant chemotherapy in patients with OCRC undergoing BTS using a SEMS. Adjuvant chemotherapy is basically recommended regardless of the cancer stage and is strongly recommended with more advanced characteristics, such as high CEA, T4, and lymphovascular invasion.

The benefits of interval appendectomy and risk factors for nonoperative management failure in the therapeutic strategy for complicated appendicitis

PURPOSE

Emergency surgery (ES) for complicated appendicitis (CA) is associated with high morbidity. Interval appendectomy (IA) decreases this rate; however, nonoperative management (NOM) is not always successful. Some patients require unplanned ES due to NOM failure (IA failure: IA-F). This study aimed to verify the benefits of IA and to evaluate the risk factors for NOM failure.

METHODS

Patients diagnosed with CA who underwent surgery between January 2012 and December 2021 were included in this study. We compared the surgical outcomes of the ES group with those of the IA success (IA-S) and IA-F groups. We also analyzed 14 factors that predicted NOM failure.

RESULTS

Among 302 patients, the rate of severe complications (Clavien-Dindo grade ≥ III) was significantly higher in the ES group (N = 165) than in the IA-S group (N = 102). The rates were equal between the ES (N = 165) and IA-F (N = 35) groups. NOM was successful in 110 patients and failed in 27. Lack of abscesses, comorbidities, high WBC count, and free air were independent risk factors for NOM failure.

CONCLUSIONS

Considering the benefits of IA and the non-inferior surgical outcomes of IA-F compared to ES, IA is a good therapeutic strategy for CA. However, in patients exhibiting four independent risk factors for NOM failure, careful monitoring of unplanned ES is necessary.

The effectiveness of fascial closure with antimicrobial-coated sutures in preventing incisional surgical site infections in gastrointestinal surgery: a systematic review and meta-analysis

The aim of this study was to conduct a systematic review and meta-analysis of the efficacy of fascial closure using antimicrobial-sutures specifically for the prevention of surgical site infections (SSIs) in gastrointestinal surgery, as part of the revision of the SSI prevention guidelines of the Japanese Society of Surgical Infectious Diseases (JSSI). We searched CENTRAL, PubMed and ICHUSHI-Web in May 2023, and included randomized controlled trials (RCTs) comparing antimicrobial-coated and non-coated sutures for fascial closure in gastrointestinal surgery (PROSPERO No. CRD42023430377). Three authors independently screened the RCTs. We assessed the risk of bias and the GRADE criteria for the extracted data. The primary outcome was incisional SSI and the secondary outcomes were abdominal wall dehiscence and the length of postoperative hospital stay. This study was supported partially by the JSSI. A total of 10 RCTs and 5396 patients were included. The use of antimicrobial-coated sutures significantly lowered the risk of incisional SSIs compared with non-coated suture (risk ratio: 0.79, 95% confidence intervals: 0.64-0.98). In subgroup analyses, antimicrobial-coated sutures reduced the risk of SSIs for open surgeries, and when monofilament sutures were used. Antimicrobial-coated sutures did not reduce the incidence of abdominal wall dehiscence and the length of hospital stay compared with non-coated sutures. The certainty of the evidence was rated as moderate according to the GRADE criteria, because of risk of bias. In conclusion, the use of antimicrobial-coated sutures for fascial closure in gastrointestinal surgery is associated with a significantly lower risk of SSI than non-coated sutures.

Pks-positive Escherichia coli in tumor tissue and surrounding normal mucosal tissue of colorectal cancer patients

A significant association exists between the gut microbiome and colorectal carcinogenesis, as well as cancer progression. It has been reported that Escherichia coli (E. coli) containing polyketide synthetase (pks) island contribute to colorectal carcinogenesis by producing colibactin, a polyketide-peptide genotoxin. However, the functions of pks+ E. coli in initiation, proliferation, and metastasis of colorectal cancer (CRC) remain unclear. We investigated the clinical significance of pks+ E. coli to clarify its functions in CRC. This study included 413 patients with CRC. Pks+ E. coli of tumor tissue and normal mucosal tissue were quantified using droplet digital PCR. Pks+ E. coli was more abundant in Stages 0-I tumor tissue than in normal mucosal tissue or in Stages II-IV tumor tissue. High abundance of pks+ E. coli in tumor tissue was significantly associated with shallower tumor depth (hazard ratio [HR] = 5.0, 95% confidence interval [CI] = 2.3-11.3, p < 0.001) and absence of lymph node metastasis (HR = 3.0, 95% CI = 1.8-5.1, p < 0.001) in multivariable logistic analyses. Pks+ E. coli-low and -negative groups were significantly associated with shorter CRC-specific survival (HR = 6.4, 95% CI = 1.7-25.6, p = 0.005) and shorter relapse-free survival (HR = 3.1, 95% CI = 1.3-7.3, p = 0.01) compared to the pks+ E. coli-high group. Pks+ E. coli was abundant in Stages 0-I CRC and associated with CRC prognosis. These results suggest that pks+ E. coli might contribute to carcinogenesis of CRC but might not be associated with tumor progression.

Oncologic investigation of the interval from stent placement to surgery in patients with obstructive colorectal cancer

PURPOSE

Self-expandable metallic stent (SEMS) placement is widely used as a bridge to surgery (BTS) procedure for obstructive colorectal cancer. However, evidence regarding the optimal interval between SEMS placement and elective surgery is lacking.

METHODS

We retrospectively collected data from patients with BTS between January 2013 and October 2021. Inverse probability treatment-weighted propensity score analyses were used to compare short- and long-term outcomes between the short-interval (SI) and long-interval (LI) groups, using a cutoff of 20 days.

RESULTS

In total, 138 patients were enrolled in this study (SI group, n = 63; LI group, n = 75). In the matched cohort, the patients' backgrounds were well balanced. The incidence of Clavien-Dindo grade ≥ II postoperative complications was not significantly different between the SI and LI groups (19.0% vs. 14.0%, P = 0.47). There were no significant differences between the SI and LI groups in the 3-year recurrence-free survival (68.0% vs. 76.4%, P = 0.73) or 3-year overall survival rates (86.0% vs. 90.6%, P = 0.72).

CONCLUSIONS

A longer interval did not deteriorate the oncological outcomes. Individual perioperative management with an appropriate interval to improve the patient's condition is required to ensure safe surgery.

Impact of resection for ovarian metastases from colorectal cancer and clinicopathologic analysis: A multicenter retrospective study in Japan

Aim

The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics.

Methods

In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors.

Results

The study included 296 patients with ovarian metastasis. The 3-y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3-y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P < 0.01] and noncurative resection vs nonresection [P < 0.01]). In the multivariate analysis of prognostic factors, tumor size of ovarian metastasis (P < 0.01), bilateral ovarian metastasis (P = 0.01), peritoneal metastasis (P < 0.01), pulmonary metastasis (P = 0.04), liver metastasis (P < 0.01), and remnant of ovarian metastasis (P < 0.01) were statistically significantly different.

Conclusion

The prognosis after curative resection for solitary ovarian metastases was shown to be relatively favorable as Stage IV colorectal cancer. Resection of ovarian metastases, not only curative resection but also noncurative resection, confers a survival benefit. Prognostic factors were large ovarian metastases, bilateral ovarian metastases, the presence of extraovarian metastases, and remnant ovarian metastases.

Recent evidence for subcutaneous drains to prevent surgical site infections after abdominal surgery: A systematic review and meta-analysis

BACKGROUND

Surgical site infections (SSIs) increase mortality, hospital stays, additional medical treatment, and medical costs. Subcutaneous drains prevent SSIs in gynecological and breast surgeries; however, their clinical impact in abdominal surgery remains unclear.

AIM

To investigate whether subcutaneous drains were beneficial in abdominal surgery using a systematic review and meta-analysis.

METHODS

The database search used PubMed, MEDLINE, and the Cochrane Library. The following inclusion criteria were set for the systematic review: (1) Randomized controlled trial studies comparing SSIs after abdominal surgery with or without subcutaneous drains; and (2) Studies that described clinical outcomes, such as SSIs, seroma formation, the length of hospital stays, and mortality.

RESULTS

Eight studies were included in this meta-analysis. The rate of total SSIs was significantly lower in the drained group (54/771, 7.0%) than in the control group (89/759, 11.7%), particularly in gastrointestinal surgery. Furthermore, the rate of superficial SSIs was slightly lower in the drained group (31/517, 6.0%) than in the control group (49/521, 9.4%). No significant differences were observed in seroma formation between the groups. Hospital stays were shorter in the drained group than in the control group.

CONCLUSION

Subcutaneous drains after abdominal surgery prevented SSIs and reduced hospital stays but did not significantly affect seroma formation. The timing of drain removal needs to be reconsidered in future studies.

Successful management of malignant colovesical fistula using covered colonic self-expanding metallic stent: a case report

BACKGROUND

A colovesical fistula (CVF) is commonly treated by resection of the intestine containing the fistula or creation of a defunctioning stoma. We herein report a case of successful fistula closure and avoidance of colostomy after placement of a covered colonic self-expanding metallic stent (SEMS) as a palliative treatment for a malignant CVF.

CASE PRESENTATION

A 75-year-old man undergoing infusional 5-fluorouracil and irinotecan chemotherapy plus bevacizumab for recurrent peritoneal dissemination of rectal cancer was admitted to our hospital because of fecaluria with a high-grade fever. Blood tests showed a moderate inflammatory reaction (white blood cell count, 9200/mm3; C-reactive protein, 11.03 mg/dL; procalcitonin, 1.33 ng/mL). Urinary sediment examination showed severe bacteriuria. Abdominal contrast-enhanced computed tomography showed intravesical gas, thickening of the posterior wall of the bladder, and irregular thickening of the sigmoid colon wall contiguous with the posterior bladder wall. Magnetic resonance imaging (MRI) clearly showed a fistula between the bladder and sigmoid colon. Colonoscopy revealed a circumferential malignant stricture 15 cm from the anal verge, and a fistula to the bladder was identified by water-soluble contrast medium. We diagnosed a complicated urinary tract infection (UTI) associated with a CVF due to peritoneal dissemination and started empirical treatment with sulbactam/ampicillin. Given the absence of active inflammatory findings around the fistula on MRI and the patient's physical frailty, we decided to place a covered SEMS to close the fistula. Under fluoroscopic and endoscopic guidance, a covered colonic SEMS of 80-mm length and 20-mm diameter was successfully deployed, and the fistula was sealed immediately after placement. Urine culture on day 3 after stenting was negative for bacteria, and a contrast study on day 5 showed no fistula. The patient was discharged home on day 6 with no complications. The UTI did not recur for 4 months after discharge.

CONCLUSIONS

A covered colonic SEMS was useful for sealing a malignant CVF in a patient unfit for surgery, and MRI was valuable to determine the status of the fistula. A covered colonic SEMS could be an alternative to surgical treatment for CVFs in patients who require palliative care.

Artificial intelligence-based analysis of time-lapse images of sphere formation and process of plate adhesion and spread of pancreatic cancer cells

Background: Most pancreatic cancers are pancreatic ductal adenocarcinomas (PDAC). Spherical morphology formed in three-dimensional (3D) cultures and the effects of anticancer drugs differ between epithelial and mesenchymal PDAC cell lines. In the human pancreas, cancer cells form 3D tumors, migrate to adjacent tissues, and metastasize to other organs. However, no effective methods exist to examine the ability of the tumor mass to migrate to surrounding tissues in vitro. We used spheres formed in 3D culture to investigate whether the migratory ability of tumors of PDAC cell lines, including epithelial and mesenchymal cell lines, varies. Methods: Sphere formation and adhesion and spread on culture plates were examined by artificial intelligence-based analysis of time-lapse imaging using five epithelial and three mesenchymal PDAC cell lines. Fused and non-fused areas of the sphere surface during sphere formation on low-attachment plates, the adhesion area to normal culture plates, and the sphere area maintaining its original form during adhesion to plates were measured. Results: Immunocytochemical staining confirmed that E-cadherin was highly expressed in epithelial PDAC spheres, as was vimentin in mesenchymal PDAC spheres, in 2D culture. When forming spheres using low-attachment plates, most epithelial PDAC cell lines initially showed decreased sphere area, and then the covering cells fused to form a smooth surface on the sphere. Mesenchymal PANC-1 and MIA PaCa-2 cells showed little reduction in sphere area and few areas of sphere surface fusion. When formed PDAC spheres were seeded onto normal culture plates, spheres of epithelial PK-8 cells-which have the highest E-cadherin expression, form numerous cysts, and have smooth sphere surfaces-did not adhere to normal plates even after 60 h, and epithelial PK45-P and T3M-4 spheres hardly adhered. Conversely, the area of adhesion and spread of mesenchymal PANC-1 and KP4 cell spheres on normal plates markedly increased from early on, forming large areas of attachment to plates. Conclusion: Seeding spheres formed in 3D culture onto culture plates can clarify differences in tumor migration potential to surrounding areas. The masses formed by each PDAC cell line varied in migratory ability, with mesenchymal PDAC masses being more migratory than epithelial PDAC masses.

Surgical Site Infections in Gastroenterological Surgery

Surgical site infections (SSIs) remain one of the most common serious surgical complications and are the second most frequent healthcare-associated infection. Patients with SSIs have a significantly increased postoperative length of hospital stay, hospital expenses, and mortality risk compared with patients without SSIs. The prevention of SSI requires the integration of a range of perioperative measures, and approximately 50% of SSIs are preventable through the implementation of evidence-based preventative strategies. Several international guidelines for SSI prevention are currently available worldwide. However, there is an urgent need for SSI prevention guidelines specific to Japan because of the differences in the healthcare systems of Japan versus western countries. In 2018, the Japan Society for Surgical Infection published SSI prevention guidelines for gastroenterological surgery. Although evidence-based SSI prevention guidelines are now available, it is important to consider the appropriateness of these guidelines depending on the actual conditions in each facility. A systemic inflammatory host response is a hallmark of bacterial infection, including SSI. Therefore, blood inflammatory markers are potentially useful in SSI diagnosis, outcome prediction, and termination of therapeutic intervention. In this review, we describe the current guideline-based perioperative management strategies for SSI prevention, focusing on gastroenterological surgery and the supplemental utility of blood inflammatory markers.

Segmental or right hemi-colectomy? The optimal surgical procedure for transverse colon cancer: a propensity score-matched, multicenter, retrospective study

PURPOSE

Extended colectomy is sometimes chosen for treatment of transverse colon cancer (TCC) because of concerns about short- and long-term outcomes. However, there is still a lack of evidence regarding the optimal surgical procedure.

METHODS

We retrospectively collected and analyzed data of patients who underwent surgical treatment of pathological stage II/III TCC at four hospitals from January 2011 to June 2019. We excluded the patients with TCC located at distal transverse colon, and just evaluated and analyzed proximal and middle third TCC. Inverse probability treatment-weighted propensity score analyses was used to compare short- and long-term outcomes between patients who underwent segmental transverse colectomy (STC) and those who underwent right hemicolectomy (RHC).

RESULTS

In total, 106 patients were enrolled in this study (STC group, n = 45; RHC group, n = 61). The patients' backgrounds were well balanced after matching. The incidence of major postoperative complications (Clavien-Dindo grade ≥ III) was not significantly different between the STC and RHC groups (4.5% vs. 5.6%, respectively; P = 0.53). The 3-year recurrence-free survival and overall survival rates were not significantly different between the STC and RHC groups (88.2% vs. 81.8%, P = 0.86 and 90.3% vs. 91.9%, P = 0.79, respectively).

CONCLUSION

RHC has no significant benefits over STC with respect to either short- or long-term outcomes. STC with necessary lymphadenectomy could be an optimal procedure for proximal and middle TCC.

The prediction of pathological complete response after total neoadjuvant therapy for locally advanced rectal cancer using versatile liquid biopsy

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Background: Total neoadjuvant therapy (TNT) has conferred a dramatic paradigm shift in the treatment for locally advanced rectal cancer (LARC), which can prolong the survival associated with high pathological complete response (pCR) rate and introduce non-operative management (NOM). However, useful biomarkers predicting the treatment efficacy of TNT and the prognosis has not been developed. Our previous study demonstrated that volume of blood long- and short-fragments DNA ( > 300 bp and < 180 bp) in LINE-1 gene are derived from tumor cell necrosis, and normal cell apoptosis, and the ratio (LSR) could reflect tumor growth or shrinkage, and minimal residual disease. Methods: A total of 17 LARC patients receiving consolidation TNT consisting of short-course radiation (5Gy x 5days) and 4 courses of CapOX, followed by total mesorectal excision were included. Blood concentrations of long-, short-fragment DNA and LSR in neoadjuvant phase were serially measured at pre-treatment, every treatment cycle, and pre-operation by real-time PCR. Results: Median age of patients were 64 years old and 65% were female. Clinical stage (IIa/IIc/IIIb/IIIc) were 2/1/8/6, respectively. Down staging was shown in 88% of patients. Tumor regression grade (0/1a/1b/2/3(pCR)) were 1/2/3/34/7(41%), respectively. Only 44% of patients had elevated CEA levels before TNT, which indicates less usefulness as the biomarker. The dynamics of the LSR in the entire cohort showed the gradual decrease until pre-operative phase (decrease to 77.8%). The LSR change from pre-treatment (or just after SCRT) to early preoperative treatment phase (1 or 2 course after CapOX) was significantly greater in the pCR(+)(n = 7) than the pCR(-)(n = 10) groups (66.8% vs. 101%, p = 0.03). The AUC of ROC analysis was 0.72 (cut off: 66.8%). Conclusions: NGS based liquid biopsy is the gold standard for the cancer prediction and monitoring, but limitations such as unsatisfied sensitivity and high cost are still involved. However, LSR measurement has great benefits on those points. Early phase LSR measurement could be a good predictive marker for the response of TNT and might be clinically useful for optimizing the preoperative therapy.

Useful Preoperative Simulation of Laparoscopic Surgery for Rectal Cancer in Patients with Kyphosis

Kyphosis complicates abdominal surgery. Here, we report a case of rectal cancer in a patient with kyphosis who underwent successful laparoscopic surgery after a preoperative simulation. An 81-year-old woman with rectal cancer was admitted to our department, and laparoscopic surgery was planned. Physical examination revealed severe kyphosis. To ensure successful laparoscopic surgery, we conducted a detailed preoperative simulation, including three-dimensional CT simulations of port arrangement and anatomy, simulation of body position, selection of surgical instruments, and preoperative discussion with the anesthesiologist. We planned to insert the first port in the umbilical region for pneumoperitoneum and the camera port in the ventral region under pneumoperitoneum. We planned to insert the ports on the right side of the patient's body from the caudal regions, after considering the location of the inferior mesenteric artery and the limitations in degrees and space attributable to the costal arch and promontorium. Beach chair position was planned. We used a fan-shaped retractor and sponge retractor to remove the small intestine from the surgical view. In preoperative discussions with the anesthesiologist, we decided to maintain pneumoperitoneum pressure at less than 8 mm Hg during the operation, to safeguard respiratory function. Lower anterior resection with D2 lymph node dissection was performed, without intraoperative complications. At 2 years postoperatively, the patient was healthy with no signs of recurrence. Laparoscopic surgery appears to be a suitable choice for patients with kyphosis. We believe that preoperative simulation will result in successful outcomes.

Postoperative infectious complications have a negative oncological impact in patients after stent placement with malignant large bowel obstruction

PURPOSE

In this study, we aimed to investigate the oncological impact of postoperative infection in patients with malignant large bowel obstruction managed by self-expandable metallic stent placement as a bridge to surgery.

METHODS

The cohort of this multicenter retrospective study comprised 129 patients with pathological stage II/III malignant large bowel obstruction who had undergone bridge to surgery. Patients were allocated to no-postoperative infection (n = 116) and postoperative infection groups (n = 13).

RESULTS

The postoperative infection group had a significantly greater proportion of men, fewer harvested lymph nodes, and longer postoperative hospital stays than did the no-postoperative infection group. Self-expandable metallic stent-related variables, including clinical failure, were not associated with postoperative infection. Male sex and low body mass index were identified as risk factors for postoperative infection by multivariate logistic regression. Three-year relapse-free survival rates were 75.5% and 30.8% in the no-postoperative infection and postoperative infection groups, respectively; this difference is statistically significant. Male sex, postoperative infection, and T4 were identified as independent prognostic factors by multivariate Cox proportional hazard analysis. The postoperative infection group had a significantly higher total recurrence rate and shorter interval to recurrence than did the no-postoperative infection group.

CONCLUSION

To the best of our knowledge, this is the first study to show that postoperative infection in bridge to surgery patients has a negative oncological impact. This finding indicates that further improvement in perioperative management of bridge to surgery patients is required to minimize postoperative infection and that patient-risk stratification and additional therapy would contribute to improving oncological outcomes.

Management of inguinal lymph node metastases from rectal and anal canal adenocarcinoma

AIM

The surgical treatment of inguinal lymph node (ILN) metastases secondary to anorectal adenocarcinoma remains controversial. This study aimed to clarify the surgical treatment and management of ILN metastasis according to its classification.

METHODS

This retrospective, multi-centre, observational study included patients with synchronous or metachronous ILN metastases who were diagnosed with rectal or anal canal adenocarcinoma between January 1997 and December 2011. Treatment outcomes were analysed according to recurrence and prognosis.

RESULTS

Among 1181 consecutively enrolled patients who received treatment for rectal or anal canal adenocarcinoma at 20 referral hospitals, 76 (6.4%) and 65 (5.5%) had synchronous and metachronous ILN metastases, respectively. Among 141 patients with ILN metastasis, differentiated carcinoma, solitary ILN metastasis and ILN dissection were identified as independent predictive factors associated with a favourable prognosis. No significant difference was found in the frequency of recurrence after ILN dissection between patients with synchronous (80.6%) or metachronous (81.0%) ILN metastases. Patients who underwent R0 resection of the primary tumour and ILN dissection had a 5-year survival rate of 41.3% after ILN dissection (34.1% and 53.1% for patients with synchronous and metachronous ILN metastases, respectively, P = 0.55).

CONCLUSION

The ILN can be appropriately classified as a regional lymph node in rectal and anal canal adenocarcinoma. Moreover, aggressive ILN dissection might be effective in improving the prognosis of low rectal and anal canal adenocarcinoma with ILN metastases; thus, prophylactic ILN dissection is unnecessary.

[Is Cell-Free DNA a Useful Biomarker for Predicting the Efficacy of Preoperative Chemotherapy for Advanced Colon Cancer?]

OBJECTIVE

To examine the potential of peripheral circulating cell-free DNA(cfDNA)as a predictor of response in patients undergoing neoadjuvant chemotherapy(NAC)for advanced colon cancer.

METHODS

We compared histological response, background factors, and cfDNA molecular volume changes in cT4 and cT3N+ colon cancer patients.

RESULTS

Six of 11 patients responded. The patients with muc and pap histology were non-responders. There was no relationship between CEA or cfDNA levels and response. Responders showed >50% change in DNA integrity index(=cfDNA long fragment/ short fragment ratio), while non-responders showed <50% change(p=0.015).

CONCLUSION

Our results suggest that the variability rate in DNA integrity index of peripheral blood cfDNA may be useful in predicting the therapeutic efficacy of colon NAC.

[Long-Term Response to UFT/UZEL/Bevacizumab Therapy for Lung Metastasis after Surgery for Early-Stage Colon Cancer in a Late-Stage Elderly Patient]

Late-stage elderly patients have low tolerance to chemotherapy, and they have difficulties when they are treated with standard chemotherapy. We report a case of a late-stage elderly patient who had a long-term response to UFT/UZEL/bevacizumab( Bev)therapy for lung metastasis after surgery for early-stage colon cancer. He was 82-years-old and underwent laparoscopy-assisted sigmoid colectomy for sigmoid colon cancer at another hospital. The pathological diagnosis was pT1b, ly1, v0, N0, M0, pStage Ⅰ. Six months after the surgery, a small nodule was noted in the middle lobe of the right lung. It grew five months later and was definitely diagnosed as lung metastasis. Considering his physical condition and tumor size, we opted to introduce less invasive chemotherapy instead of standard chemotherapy. UFT/UZEL/Bev was started 14 months after surgery. Although he required dose reduction due to anorexia, he safely continued the treatment with partial response (PR), which was maintained for 2 years and 6 months. While UFT/UZEL/Bev has no convincing evidence, it may be an option for vulnerable patients, especially those with non-life-threatening disease.

TGF-β1 increases cellular invasion of colorectal neuroendocrine carcinoma cell line through partial epithelial-mesenchymal transition

Epithelial–mesenchymal transition (EMT) plays a pivotal role in cancer progression and metastasis in many types of malignancies, including colorectal cancer. Although the importance of EMT is also considered in colorectal neuroendocrine carcinoma (NEC), its regulatory mechanisms have not been elucidated. We recently established a human colorectal NEC cell line, SS-2. In this study, we aimed to clarify whether these cells were sensitive to transforming growth factor beta 1 (TGF-β1) and whether EMT could be induced through TGF-β1/Smad signaling, with the corresponding NEC cell-specific changes in invasiveness. In SS-2 cells, activation of TGF-β1 signaling, as indicated by phosphorylation of Smad2/3, was dose-dependent, demonstrating that SS-2 cells were responsive to TGF-β1. Analysis of EMT markers showed that mRNA levels changed with TGF-β1 treatment and that E-cadherin, an EMT marker, was expressed in cell-cell junctions even after TGF-β1 treatment. Invasion assays showed that TGF-β1-treated SS-2 cells invaded more rapidly than non-treated cells, and these cells demonstrated increased metalloproteinase activity and cell adhesion. Among integrins involved in cell-to-matrix adhesion, α2-integrin was exclusively upregulated in TGF-β1-treated SS-2 cells, but not in other colon cancer cell lines, and adhesion and invasion were inhibited by an anti-α2-integrin blocking antibody. Our findings suggest that α2-integrin may represent a novel therapeutic target for the metastasis of colorectal NEC cells.

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NEC cell line SS-2 is responsive to TGF-β1.

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TGF-β1 stimulation induces partial EMT, maintaining E-cadherin in SS-2 cells.

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TGF-β1-treated SS-2 cells exhibit increase in metalloproteinase activity and cell adhesion.

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α2-integrin is exclusively upregulated in TGF-β1-treated SS-2 cells.

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Use of anti-α2-integrin blocking antibody inhibits enhanced adhesion and invasion.

Colonic stent as a bridge to surgery versus emergency resection for right-sided malignant large bowel obstruction: a meta-analysis

BACKGROUND

Preoperative colonic stenting for malignant large bowel obstruction (MLBO), also called bridge to surgery (BTS), is considered a great substitute treatment for emergency resection (ER) in the left-sided colon. However, its efficacy in the right-sided colon remains controversial. This systematic review and meta-analysis aimed to compare the postoperative short-term outcomes between BTS and ER for right-sided MLBO.

METHODS

A comprehensive electronic literature search throughout December 2020 was performed to identify studies comparing short-term outcomes between BTS and ER for right-side MLBO. The main outcome measures were postoperative complications and mortality rates. A meta-analysis was performed using a fixed-effect or a random-effect method to calculate odds ratios (ORs) with 95% confidence intervals (95% CIs).

RESULTS

Seven studies were included in this meta-analysis, comprising 5136 patients, of whom 1662 (32.4%) underwent BTS and 3474 (67.6%) underwent ER. This meta-analysis demonstrated that BTS resulted in reductions in postoperative complications (OR = 0.78; 95% CI: 0.66-0.92) and mortality (OR = 0.51; 95% CI: 0.28-0.92) than ER.

CONCLUSION

The results of this meta-analysis indicate that BTS for right-sided MLBO confers preferable short-term outcomes as well as for left-sided. This suggests that BTS results in a reduction of postoperative complications and mortality for right-sided MLBO than ER.

A rapidly growing small intestinal metastasis from lung cancer

Small intestinal metastasis from lung cancer is a relatively rare occurrence, and often causes intestinal obstruction, gastrointestinal perforation, and/or gastrointestinal bleeding making it is an oncological emergency. Many patients have been reported to undergo emergency surgery owing to the rapid progression of the intestinal metastatic lesion; however, information regarding the changes that occur in such metastases over time remains lacking. Therefore, we analyzed 4 patients who had small intestinal metastases arising from lung cancer, who were treated during a 10-year period (January 2011 to December 2020), and whose tumor diameter changes were recorded. The average tumor volume growth rate was 1.48 (1.31-1.78) -fold, and the median observation period was 22 (4-39) days, showing a rapid increase. Histopathologically, in patients with a high degree of primary tumor atypia, rapid tumor growth caused by intratumoral hemorrhage may occur. This was considered to be one of the factors responsible for the rapid increase in tumor volume.