Low mitochondrial DNA copy number induces chemotherapy resistance via epithelial-mesenchymal transition by DNA methylation in esophageal squamous cancer cells

Background

Esophageal squamous cell carcinoma (ESCC) is one of the most severe cancers and is characterized by chemotherapy resistance and poor prognosis associated with epithelial-mesenchymal transition (EMT). In a previous study, a low mitochondrial DNA (mtDNA) copy number was associated with poorer prognosis and induced EMT in ESCC. However, the detailed mechanism related to mtDNA copy number and EMT is unclear. The aim of this study was to clarify the mechanism by which a change in mtDNA copy number contributes to EMT and to examine treatment of chemotherapy resistance in ESCC.

Methods

The association between low mtDNA copy number and chemotherapy resistance was investigated using specimens from 88 patients who underwent surgery after neoadjuvant chemotherapy. Then, the mtDNA content of human ESCC cell lines, TE8 and TE11, was depleted by knockdown of mitochondrial transcription factor A expression. The present study focused on modulation of mitochondrial membrane potential (MMP) and DNA methylation as the mechanisms by which mtDNA copy number affects EMT. mRNA and protein expression, chemotherapy sensitivity, proliferation, MMP and DNA methylation were evaluated, and in vitro and in vivo assays were conducted to clarify these mechanisms.

Results

ESCC patients with decreased mtDNA copy number who underwent R0 resection after neoadjuvant chemotherapy had significantly worse pathological response and recurrence-free survival. Additionally, low mtDNA copy number was associated with resistance to chemotherapy in vitro and in vivo. mtDNA controlled MMP, and MMP depolarization induced EMT. Depletion of mtDNA and low MMP induced DNA methylation via a DNA methylation transcription factor (DNMT), and a DNMT inhibitor suppressed EMT and improved chemotherapy sensitivity in mtDNA-depleted ESCC cells, as shown by in vitro and in vivo assays.

Conclusion

This study showed that decreased mtDNA copy number induced EMT via modulation of MMP and DNA methylation in ESCC. Therapeutic strategies increasing mtDNA copy number and DNMT inhibitors may be effective in preventing EMT and chemosensitivity resistance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03594-2.

The Phase II Study of Panitumumab in Chemotherapy-Naïve Frail or Elderly Patients with RAS Wild-type Colorectal Cancer: OGSG 1602 Final Results

BACKGROUND

We previously reported the response rate of a phase II OGSG1602 study on panitumumab in chemotherapy-naive frail or elderly patients with RAS wild-type unresectable colorectal cancer (CRC) [Terazawa T, Kato T, Goto M, et al. Oncologist. 2021;26(1):17]. Herein, we report a survival analysis.

METHODS

Patients aged ≥65 years and considered unsuitable for intensive chemotherapy or aged ≥76 years were enrolled. Primary tumors located from the cecum to the transverse colon were considered right-sided tumors (RSTs); those located from the splenic flexure to the rectum were considered left-sided tumors (LSTs).

RESULTS

Among the 36 enrolled patients, 34 were included in the efficacy analysis, with 26 and 8 having LSTs and RSTs, respectively. The median progression-free survival (PFS) and overall survival (OS) were 6.0 [95% CI, 5.4-10.0] and 17.5 months (95% CI, 13.8-24.3), respectively. Although no significant differences existed in PFS between patients with LST and RST {6.6 (95% CI, 5.4-11.5) vs. 4.9 months [95% CI, 1.9-not available (NA), P = .120]}, there were significant differences in OS [19.3 (95% CI, 14.2-NA) vs.12.3 months (95% CI, 9.9-NA), P = .043].

CONCLUSION

Panitumumab showed favorable OS in frail or elderly patients with RAS wild-type CRC and no prior exposure to chemotherapy. Panitumumab may be optimal for patients with LSTs (UMIN Clinical Trials Registry Number UMIN000024528).

Protocol of OGSG 1901: a phase II trial of ramucirumab plus irinotecan for patients with early relapsed gastric cancer during or after adjuvant docetaxel plus S - 1 therapy

BACKGROUND

Although docetaxel plus S-1 adjuvant chemotherapy after gastrectomy with D2 lymphadenectomy has been a standard of treatment for stage III gastric cancer, there is no established chemotherapy for patients with recurrence during or within six months after the completion of adjuvant docetaxel plus S-1 therapy.

METHODS

The OGSG 1901 trial is a prospective, open-label, multicenter, phase II trial evaluating ramucirumab plus irinotecan for gastric cancer patients with early relapse after adjuvant docetaxel plus S-1 therapy. The key eligibility criteria were: 1) histologically confirmed gastric adenocarcinoma 2) patients who were on docetaxel plus S-1 adjuvant chemotherapy after the confirmation of pathological stage III, 3) patients with early relapse, i.e., recurrence during or within 6 months after the completion of docetaxel plus S-1 therapy, and 4) patient with Eastern Cooperative Oncology Group performance status of 0-1. Irinotecan (150 mg/m2, day 1) and ramucirumab (8 mg/kg, day 1) will be administered every 2 weeks. The primary endpoint is overall survival, and the secondary endpoints are overall response rate, progression-free survival, and safety. The number of patients has been set at 40 based on the threshold and expected median survival times of 7 and 11 months, respectively, with a one-sided alpha error of 0.05 and power of 0.80. The enrollment and follow-up periods are 2 and 1.5 years, respectively.

DISCUSSION

The results of this trial will indicate whether the ramucirumab with irinotecan regimen has the potential to be a recommended treatment regimen for patients with recurrence gastric cancer during or within 6 months after the completion of adjuvant docetaxel plus S-1 therapy.

TRIAL REGISTRATION

This study was registered in the Japan Registry of Clinical Trials ( jRCTs05119071 , October 6, 2019).

Laparoscopic resection for imatinib-resistant recurrent tumors of gastric gastrointestinal stromal tumors: A case report

An 82-year-old woman underwent laparoscopic partial gastrectomy for fundal gastrointestinal stromal tumor (GIST) in a previous hospital. She visited our hospital for the treatment of recurrence, because two nodules, one each on the gastric suture line and in the peritoneum of the left diaphragm, were pointed out. Imatinib therapy was immediately initiated, and the size of both nodules decreased. However, the one on the gastric suture line showed regrowth after 4 years, which was eventually diagnosed as imatinib-resistant GIST. Hence, laparoscopic partial gastrectomy with peritoneal imatinib-sensitive nodule resection was subsequently performed. Pathologically, the nodule on the gastric suture line was confirmed as a GIST, whereas the other was diagnosed as a hyaline-degenerated GIST. Surgical intervention for imatinib-resistant GISTs has been reported to improve the outcomes of recurrent GISTs. Laparoscopic resection of localized imatinib-resistant GISTs could safely and less invasively be performed in this case; however, caution should be paid to the indication of the approach.

Pimitespib in patients with advanced gastrointestinal stromal tumor (CHAPTER-GIST-301): a randomized, double-blind, placebo-controlled phase 3 trial

BACKGROUND

Prognosis of advanced gastrointestinal stromal tumors (GIST) refractory to tyrosine kinase inhibitors (TKIs) is poor. This randomized, placebo-controlled, phase 3 trial evaluated the efficacy and safety of pimitespib, a novel heat shock protein 90 inhibitor, in advanced GIST refractory to standard TKIs.

PATIENTS AND METHODS

Patients with histologically confirmed GIST refractory to imatinib, sunitinib, and regorafenib were randomized 2:1 to oral pimitespib 160 mg/day or placebo for five consecutive days per week in 21-day cycles. Following disease progression by blinded central radiological review (BCRR), crossover to open-label pimitespib was permitted. The primary endpoint was progression-free survival (PFS) by BCRR in the full analysis set. Secondary endpoints included overall survival (OS) adjusted using the rank preserving structural failure time method to reduce the expected confounding impact of crossover.

RESULTS

From Oct 31, 2018 to Apr 30, 2020, 86 patients were randomized to pimitespib (n=58) or placebo (n=28). Median PFS was 2.8 months (95% CI 1.6-2.9) with pimitespib versus 1.4 months (0.9-1.8) with placebo (hazard ratio [HR] 0.51 [95% CI 0.30-0.87]; one-sided p=0.006). Pimitespib showed an improvement in crossover-adjusted OS compared with placebo (HR 0.42 [0.21-0.85], one-sided p=0.007). Seventeen (60.7%) patients receiving placebo crossed-over to pimitespib; median PFS after crossover was 2.7 (95% CI 0.7-4.1) months. The most common (≥30%) treatment-related adverse events (AEs) with pimitespib were diarrhea (74.1%) and decreased appetite (31.0%); the most common (≥10%) grade ≥3 treatment-related AE was diarrhea (13.8%). Treatment-related AEs leading to pimitespib discontinuation occurred in 3 (5.2%) patients.

CONCLUSION

Pimitespib significantly improved PFS and crossover-adjusted OS compared with placebo and had an acceptable safety profile in patients with advanced GIST refractory to standard TKIs.

The Impact of Perioperative Fluid Balance on Postoperative Complications after Esophagectomy for Esophageal Cancer

Background: Perioperative fluid balance is an important indicator in the management of esophageal cancer patients who undergo esophagectomy. However, the association between perioperative fluid balance and postoperative complications after minimally invasive esophagectomy (MIE) remains unclear. Methods: This study included 115 patients with thoracic esophageal squamous cell cancer who underwent MIE between January 2018 and January 2020. We retrospectively evaluated the association between perioperative fluid balance from during surgery to postoperative day (POD) 2, and postoperative complications. Results: The patients were divided into lower group and higher group based on the median fluid balance during surgery and at POD 1 and POD 2. We found that the higher group at POD 1 (≥3000 mL) was the most important indicator of postoperative complications, such as acute pneumonia within 7 days after surgery, and anastomotic leakage (p = 0.029, p = 0.024, respectively). Moreover, the higher group at POD 1 was a significant independent factor for acute postoperative pneumonia by multivariate analysis (OR: 3.270, 95% CI: 1.077–9.929, p = 0.037). Conclusion: This study showed that fluid overload at POD 1 had a negative influence on postoperative complications in patients with esophageal cancer. The fluid balance must be strictly controlled during the early postoperative management of patients undergoing esophageal cancer surgery.

Robotic Distal Gastrectomy Reduces Drain Amylase Values in Patients With a Small Pancreas-left Gastric Artery Angle

PURPOSE

Pancreatic fistula is a severe complication after laparoscopic distal gastrectomy (LDG). We previously evaluated the pancreas-left gastric artery angle (PLA) as a risk indicator for developing a pancreatic fistula after LDG. This study evaluated the incidence of pancreatic fistula with robotic distal gastrectomy (RDG) in comparison to LDG from the view of the PLA.

MATERIALS AND METHODS

An association between the PLA and the incidence of pancreatic fistula in 165 patients who underwent either RDG (n=45) or LDG (n=120) was investigated retrospectively.

RESULTS

RDG patients had significantly lower drain amylase values (postoperative day 2) than LDG patients. As opposed to LDG patients, drain amylase values were similar for patients with small (PLA <62 degrees) and large (PLA ≥62 degrees) PLA in RDG patients.

CONCLUSION

Robotic surgery may reduce the risk of postoperative pancreatic fistula in patients with a small PLA.

Pathological Regression of Lymph Nodes Better Predicts Long-term Survival in Esophageal Cancer Patients Undergoing Neoadjuvant Chemotherapy Followed by Surgery

OBJECTIVE

To evaluate pathological response to NAC in metastatic LNs, and assess its clinical prognostic significance in patients with EC.

SUMMARY OF BACKGROUND DATA

The pathological response to preoperative treatment is commonly evaluated in the PT. However, LN metastases strongly correlate with systemic micro-metastases. Thus, pathological evaluation of LN response could more accurately predict prognosis in EC patients undergoing NAC before surgery.

METHODS

We enrolled 371 consecutive patients who underwent triplet NAC followed by surgery for EC between January 2010 and December 2016. Pathological LN regression grade was defined by the proportion of viable tumor area within the whole tumor bed area for all metastatic LNs: grade I, >50%; II, 10%-50%; III, <10%; and IV, 0%. We analyzed the correlation of grade with clinico-pathological parameters.

RESULTS

Among 319 patients with clinically positive LNs, pathological LN regression grades were I/II/III/IV in 115/51/58/95 patients, and 191 patients (59.9%) showed discordance between the PT and LN pathological regression grades. LN regression grade significantly correlated with cN positive number, ypTNM, lymphovascular invasion, and clinical/pathological PT response. Multivariate analysis for recurrence-free survival revealed that LN regression grade [hazard ratio (HR) = 2.25, P < 0.001], ypT (HR = 1.65, P = 0.005), and ypT (HR = 1.62, P = 0.004) were independent prognostic factors, but not pathological PT regression grade (P = 0.67).

CONCLUSIONS

Compared to PT response, pathological LN response better predicted long-term survival in EC patients who received NAC plus curative surgery.

Impact of tumor-related factors and inter-institutional heterogeneity on preoperative T staging for gastric cancer

Background: To improve the diagnostic accuracy of preoperative T staging in gastric cancer, the authors evaluated tumor-related factors that might affect the diagnosis. Materials & methods: The authors analyzed the data of cT2-4b gastric cancer patients enrolled in the prospective, multicenter JCOG1302A study. They used contrast-enhanced computed tomography to analyze the association between tumor-related factors and the diagnostic accuracy of T3-4b staging for gastric cancer. Results: Among 876 cT3-4b tumors, the diagnostic accuracy was relatively low in the lower third of the stomach compared with those in the upper or middle. A multivariable analysis revealed that accuracy was higher in the lesser curvature or entire circumference region than in other areas (p < 0.001), in macroscopic types 3/5 than in types 0/1/2 (p = 0.003) and in the undifferentiated histological type than in the differentiated type (p = 0.011). Conclusion: The authors found tumor-related factors affecting preoperative T staging by enhanced computed tomography.

Risk Factors for Para-Aortic Lymph Node Metastasis in Esophagogastric Junction Cancer: Results from a Prospective Nationwide Multicenter Study

BACKGROUND

Several studies have reported a high incidence of metastasis to para-aortic station 16a2lat (no. 16a2lat) among patients with esophagogastric junction (EGJ) cancer. However, the risk factors for no. 16a2lat metastasis are unclear. This study aimed to clarify the risk factors for no. 16a2lat metastasis in patients with EGJ cancer.

METHODS

Among 371 prospectively enrolled patients with EGJ cancer, 344 patients who underwent no. 16a2lat lymph node dissection were analyzed. Background factors were compared between the patients with and those without no. 16a2lat metastasis. The association between the histologic status of 10 regional lymph node stations and that of no. 16a2lat metastasis was evaluated.

RESULTS

Among the background factors, clinical N2-3 was the only independent risk factor for no. 16a2lat metastasis (odds ratio [OR], 5.90; p = 0.003). The metastasis rate of no. 16a2lat was 11.8% (11/93) for the patients with cN2-3 disease and 2.0% (5/251) for those with cN0-1 disease. The multivariate analysis showed that nos. 2 and 7 metastases were independent risk factors for no. 16a2lat metastasis, with respective ORs of 5.53 (p = 0.018) and 4.00 (p = 0.041). The patients with neither station no. 2 nor no. 7 metastasis did not exhibit no. 16a2lat metastasis, whereas the rate of no. 16a2lat metastasis was 23.7% for the patients with metastases of both stations.

CONCLUSIONS

Clinical N2-3 and histologic positivity of station nos. 2 and 7 were independent risk factors for no. 16a2lat metastasis. These findings could potentially assist in determining the indication for no. 16a2lat dissection for patients with EGJ cancer.

Real-world effectiveness of third- or later-line treatment in Japanese patients with HER2-positive, unresectable, recurrent or metastatic gastric cancer: a retrospective observational study

Background

Real-world evidence on the preference for and effectiveness of third- or later-line (3L +) monotherapy for HER2-positive gastric cancer is limited in Japan. This study evaluated the utility of nivolumab, irinotecan, and trifluridine/tipiracil (FTD/TPI) monotherapy as 3L + treatment in Japanese patients with HER2-positive gastric/gastroesophageal junction (G/GEJ) cancer who were previously treated with trastuzumab.

Methods

In this multicenter, retrospective, observational study (20 centers), data of eligible patients were extracted from medical records (September 22, 2017–March 31, 2020), with follow-up until June 30, 2020. Outcomes included overall survival (OS), real-world progression-free survival (rwPFS), time to treatment failure (TTF), objective response rate (ORR; complete response [CR] + partial response [PR]), and disease control rate (DCR).

Results

Of 127 enrolled patients, the overall analysis population comprised 117 patients (median [range] age, 71 [38–89] years). The most commonly prescribed 3L + monotherapy was nivolumab (n = 100), followed by irinotecan (n = 12) and FTD/TPI (n = 5). The median (95% confidence interval [CI]) OS, rwPFS, and TTF were 6.2 (4.5–8.0), 1.9 (1.5–2.3), and 1.8 (1.5–2.2) months, respectively, at median (range) 150 (25–1007) days of follow-up. The ORR (CR + PR) and DCR were 9.0% (1% + 8%) and 32.0%, respectively. Factors such as higher neutrophil–lymphocyte ratio (≥ 2.54), Glasgow prognostic score (≥ 1), Eastern Cooperative Oncology Group performance status (ECOG PS; ≥ 2), and hepatic metastasis significantly impacted OS.

Conclusions

The observed OS in this study for HER2-positive G/GEJ cancer was shorter than that reported previously, suggesting that the effectiveness of nivolumab, irinotecan, or FTD/TPI as 3L + therapy may be limited.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10147-022-02162-4.

Efficacy and safety of regorafenib in Japanese patients with advanced gastrointestinal stromal tumors

BACKGROUND

Regorafenib is an oral multi-kinase inhibitor that has been established as third-line treatment for patients after the failure of imatinib and sunitinib. However, since clinical data of regorafenib in the Japanese population are still lacking, the management of regorafenib is mainly based on the clinical experience of each oncologist. The aim of this study was to evaluate the efficacy and safety of regorafenib in a Japanese population.

METHODS

Thirty-three patients treated with regorafenib for metastatic and recurrent gastrointestinal stromal tumors were retrospectively enrolled. This study investigated the anti-tumor effect, including overall survival, progression-free survival, and safety, which was evaluated based on the incidence of adverse events.

RESULTS

The median overall survival of patients treated with regorafenib was 23.8 months and the 1-year overall survival rate was 80.0%, the median progression-free survival was 7.1 months and the 1-year progression-free survival rate was 40.2%. The responses to regorafenib were partial response in 3 cases (9.1%), stable disease in 17 (51.5%), progressive disease in 10 (30.3%), and non-evaluable in 3 (9.1%). The disease control rate was 54.0%. Treatment-related adverse events were reported in all patients, with the most common being hand-foot syndrome (72.7%), followed by liver damage (36.4%) and diarrhea (27.3%), and six patients (20.0%) were discontinued due to adverse events.

CONCLUSION

This is the first report of Japanese patients with gastrointestinal stromal tumors treated with regorafenib. Regorafenib showed efficacy and a manageable safety profile in Japanese patients with advanced gastrointestinal stromal tumors, which was comparable with previous studies.

Three-Year Outcomes of a Phase II Study of Perioperative Capecitabine Plus Oxaliplatin Therapy for Clinical SS/SE N1-3 M0 Gastric Cancer (OGSG 1601)

Background

We previously reported the good feasibility and favorable efficacy of perioperative capecitabine plus oxaliplatin (CapeOx) in patients (pts) with clinical T3(SS)/T4a(SE) N1-3 M0 gastric cancer (GC) in a phase II study in which the pathological response rate, the primary endpoint, of 54.1% was demonstrated. Here, we report 3-year follow-up data.

Methods

The eligibility criteria included clinical T3(SS)/T4a(SE) N1-3 M0 GC according to the Japanese Classification of Gastric Carcinoma-3rd English Edition (JCGC). Three cycles of neoadjuvant CapeOx (capecitabine, 2000mg/m² for 14 days; oxaliplatin, 130mg/m² on day 1, every 3 weeks) were administered, followed by 5 cycles of adjuvant CapeOx after D2 gastrectomy. Three-year overall survival and relapse-free survival are presented here, and analyzed by cohorts based on pathologic response rate (pRR).

Results

Thirty-seven pts were enrolled from July 2016 to May 2017, and fully evaluated for efficacy and toxicity. Thirty-three pts (89.2%) completed the planned three cycles of neoadjuvant CapeOx and underwent gastrectomy, with an R0 resection rate of 78.4% (n = 29). The overall survival (OS) rate and relapse-free survival (RFS) rate at 3 years was 83.8% (95% CI, 72.7-96.5%) and 73.0% (95% CI, 60.0-88.8%), respectively. Further, the 3-year OS rate in pts with pathological response of grade 1a (n = 13) and grade 1b or higher (n = 20) was 69.2% (95% CI: 48.2-99.5%) and 100.0%, respectively, based on JCGC. Pathological response rate was classified according to JCGC as follows: grade 0, the tumor was not affected; grade 1a, less than one-third of the tumor was affected; grade 1b, one to two thirds of the tumor was affected; grade 2, greater than or equal to two thirds was affected; and grade 3, no residual tumor. A pathological response was defined as grade 1b or greater.

Conclusion

Perioperative CapeOx showed good feasibility and favorable prognosis, especially in pts with pathological response of grade 1b or higher and was found to be useful in predicting prognosis. The data obtained using this novel approach warrant further investigation (Trial ID: UMIN000021641, jRCTs051180109).

A novel, simple, and dedicated device for endoscopic mucosal defect closure

OBJECTIVES

Endoscopic submucosal dissection (ESD) has become popular, but complications such as postoperative bleeding remain an issue. Although some methods of closing a mucosal defect with a snare and clips have been reported to be effective and safe, the snare is not a dedicated device, and the procedure is difficult and time-consuming. We aimed to find an alternative method for defect closure after ESD by developing a dedicated device.

METHODS

We have improved five prototypes. The load on the stopper when starting to tighten and loosen a loop and the maximum load on the stopper and the movement distance of the thread when sliding the stopper were measured five times for each prototype. With the 5th prototype, we finalized the design and named it FLEXLOOP. Additionally, the material and shape of the outer tube were improved. Then, the usability of FLEXLOOP was evaluated in pigs. The operation time for closing mucosal defects with the snare or FLEXLOOP was measured five times.

RESULTS

We made FLEXLOOP, which had a lower load when sliding and a higher load when loosening than the snare. The improvement of the outer tube significantly reduced the load on the sheath when sliding it. We confirmed the feasibility of mucosal defect closure with FLEXLOOP in pigs. The median operation time was 563 s (range 340-679 s) with the snare and 355 s (range 303-455 s) with FLEXLOOP (p = 0.047).

CONCLUSIONS

FLEXLOOP can be a promising option for defect closure after ESD.

A Smoke Evacuator Equipped With a Filter Contributes Enough to Safe Gas Exhaustion From the Abdominal Cavity

Surgical plume (SP) carries biological risks such as virus transmission. An evacuation system can remove SP from the surgical field, but is it safe to release evacuated gas into the operating room (OR) atmosphere? We examined this using a commercially available evacuator equipped with a filter under a laparoscopic porcine surgery model. SP was generated by activating an electrocautery or ultrasonic scalpel on the surface of the liver, and we evaluated whether DNA fragments derived from porcine tissue were present in the exhausted gas from the evacuation system into the atmosphere. DNA fragments were detected in the inlet gas of the evacuation system, while it was not detected in the outlet gas. As far as pathogen transmission via SP in the abdominal cavity is concerned, if the smoke evacuator ensures filter adsorption, it seems that there is little risk in releasing the suction gas into the atmosphere in the OR.

Current Status of Endoscopic Surgery in Japan: The 15th National Survey of Endoscopic Surgery by the Japan Society for Endoscopic Surgery

In Japan, the first endoscopic surgery, a laparoscopic cholecystectomy, was performed in 1990. Since then, operative procedures have been standardized, and the safety and efficacy of endoscopic surgery have been evaluated. In accordance with the social acceptance of endoscopic surgery as a less invasive type of surgery, the number of endoscopic procedures performed has increased in all surgical domains. The Japan Society for Endoscopic Surgery (JSES) has played an important role in the development of endoscopic surgery in Japan. Notably, a technical skills certification system for surgeons was established by the JSES to train instructors on how to teach safe endoscopic surgery. Furthermore, the JSES has conducted a national survey every 2 years. In 2019, 291,792 patients underwent endoscopic surgery in all surgical domains, such as abdominal, thoracic, mammary and thyroid gland, cardiovascular, obstetrics and gynecology, urologic, orthopedic, and plastic surgery. The 15th National Survey of Endoscopic Surgery conducted by the JSES demonstrated the status of laparoscopic surgery in Japan in 2018-2019.