Long-term response to pimitespib in postoperative recurrent gastrointestinal stromal tumors with PDGFRA D842V mutation: a case report

BACKGROUND

Exon 18 D842V, which is a point mutation from aspartic acid to valine at codon 842, is the most frequent mutation in Platelet-Derived Growth Factor Receptor alpha (PDGFRA)-mutated gastrointestinal stromal tumor (GIST). In the Japanese GIST guidelines, no standard systematic therapy is available for this type of GIST, which is refractory after recurrence. Recently, pimitespib (PIMI), a novel heat shock protein 90 (HSP90) inhibitor, was approved for the treatment of advanced GIST in a phase III study. This report presents a case of a long-term response to PIMI in GIST with PDGFRA D842V mutation.

CASE PRESENTATION

A 55-year-old woman was diagnosed with primary GIST of the stomach and underwent partial gastrectomy. Eight years after the operation, recurrent GISTs were identified as multiple recurrent peritoneal GISTs in the upper right abdomen and pelvic cavity. We administered tyrosine kinase inhibitors, but they achieved poor effects. After failure of the standard treatment, PIMI was administered and achieved a partial response in the patient. The highest reduction rate was 32.7%. After PIMI failed, we performed multiplex gene panel testing, which revealed the PDGFRA D842V mutation.

CONCLUSIONS

We report the first case of long-term response to PIMI in PDGFRA D842V mutant GIST. Pimitespib may be effective for treating GIST harboring this mutation by inhibiting HSP90.

Plasma trough concentration of imatinib and its effect on therapeutic efficacy and adverse events in Japanese patients with GIST

BACKGROUND

Imatinib mesylate (IM) is the standard chemotherapy for patients with gastrointestinal stromal tumors (GISTs) and has a favorable safety profile. Pharmacokinetics (PK), such as plasma trough concentration (Cmin), varies among patients, requiring the need for therapeutic drug monitoring (TDM) during IM administration. Despite some reports from overseas, the relationship between Cmin, adverse events (AEs), and treatment efficacy in Japanese patients with GIST has still been lacking. This study aimed to investigate the relationship between IM plasma concentration and AEs in Japanese patients with GISTs.

METHODS

This retrospective study analyzed the data of 83 patients who underwent IM treatment for GISTs at our institution between May 2002 and September 2021.

RESULTS

The IM Cmin was associated with any grade of AEs (with AEs vs. without AEs = 1294 (260-4075) vs. 857 (163-1886) ng/mL, P < 0.001), edema (with edema vs. without edema = 1278 (634-4075) vs. 1036 (163-4069) ng/mL, P = 0.017), and fatigue (with fatigue vs. without fatigue = 1373 (634-4069) vs. 1046 (163-4075) ng/mL, P = 0.044). Moreover, a Cmin ≥ 1283 ng/mL was a risk factor for severe AEs. The median progression-free survival (PFS) was 3.04 years in the lowest Cmin tertile (T1, < 917 ng/mL) compared with 5.90 years for T2 and T3 (P = 0.010).

CONCLUSION

Edema and fatigue are potentially associated with IM plasma trough concentrations of ≥ 1283 ng/mL in Japanese patients with GISTs. Further, maintaining an IM plasma trough concentration above 917 ng/mL may improve PFS.

High-frequency spin torque oscillation in orthogonal magnetization disks with strong biquadratic magnetic coupling

In this study, we numerically investigate the spin transfer torque oscillation (STO) in a magnetic orthogonal configuration by introducing a strong biquadratic magnetic coupling. The orthogonal configuration consists of top and bottom layers with in-plane and perpendicular magnetic anisotropy sandwiching a nonmagnetic spacer. The advantage of an orthogonal configuration is the high efficiency of spin transfer torque leading a high STO frequency; however, maintaining the STO in a wide range of electric current is challenging. By introducing biquadratic magnetic coupling into the orthogonal structure of FePt/spacer/Co₉₀Fe₁₀, Ni₈₀Fe₂₀ or Ni, we were able to expand the electric current region in which the stable STO is realized, resulting in a relatively high STO frequency. For example, approximately 50 GHz can be achieved in an Ni layer at a current density of 5.5 × 10⁷ A/cm². In addition, we investigated two types of initial magnetic state: out-of-plane and in-plane magnetic saturation; this leads to a vortex and an in-plane magnetic domain structure after relaxation, respectively. The transient time before the stable STO was reduced to between 0.5 and 1.8 ns by changing the initial state from out-of-plane to in-plane.

Combination of pimitespib (TAS-116) with sunitinib is an effective therapy for imatinib-resistant gastrointestinal stromal tumors

Despite the effectiveness of imatinib, most gastrointestinal stromal tumors (GISTs) develop resistance to the treatment, mainly due to the reactivation of KIT tyrosine kinase activity. Sunitinib, which inhibits the phosphorylation of KIT and vascular endothelial growth factor (VEGF) receptor, has been established as second-line therapy for GISTs. The recently-developed heat shock protein 90 (HSP90) inhibitor pimitespib (PIM; TAS-116) demonstrated clinical benefits in some clinical trials; however, the effects were limited. The aim of our study was therefore to clarify the effectiveness and mechanism of the combination of PIM with sunitinib for imatinib-resistant GISTs. We evaluated the efficacy and mechanism of the combination of PIM with sunitinib against imatinib-resistant GIST using imatinib-resistant GIST cell lines and murine xenograft models. In vitro analysis demonstrated that PIM and sunitinib combination therapy strongly inhibited growth and induced apoptosis in imatinib-resistant GIST cell lines by inhibiting KIT signaling and decreasing auto-phosphorylated KIT in the Golgi apparatus. In addition, PIM and sunitinib combination therapy enhanced antitumor responses in the murine xenograft models compared to individual therapies. Further analysis of the xenograft models showed that the combination therapy not only downregulated the KIT signaling pathway but also decreased the tumor microvessel density. Furthermore, we found that PIM suppressed VEGF expression in GIST cells by suppressing protein kinase D2 and hypoxia-inducible factor-1 alpha, which are both HSP90 client proteins. In conclusion, the combination of PIM and sunitinib is effective against imatinib-resistant GIST via the downregulation of KIT signaling and angiogenic signaling pathways.

Gastric cancer (GC) cohort of a phase 2 trial of E7389-LF (liposomal formulation of eribulin) in combination with nivolumab

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Background: Due to a lack of efficacy and long-term survival seen in previously-studied therapies, new therapies for pretreated advanced GC are warranted. E7389-LF is a new formulation that uses liposomes to encapsulate eribulin; this is anticipated to improve eribulin concentration in tumor tissues. E7389-LF and nivolumab have both shown efficacy as monotherapy in pretreated GC. E7389-LF may also synergize well with PD-1 inhibitors by acting as a cytotoxic therapy and by modulating the tumor microenvironment. Methods: Patients (pts) with unresectable and measurable GC, esophageal cancer, or small cell lung cancer who were previously treated with 1 (2 for GC) chemotherapy regimens were enrolled in the phase 2 part of Study 120 and treated with E7389-LF 2.1 mg/m2 plus nivolumab 360 mg every 3 weeks (Q3W). In the GC cohort, pts had to show disease progression from combination therapy including a platinum drug + fluoropyrimidine (1st-line therapy) and a taxane-containing regimen (2nd-line therapy). The primary objective of the phase 2 part was to evaluate the objective response rate (ORR); secondary objectives included safety, progression-free survival (PFS), and pharmacokinetics. Other efficacy (including overall survival [OS]) and biomarker objectives were exploratory. Tumor responses were assessed by the investigators per RECIST v1.1. Results: 31 GC pts were included; median age was 63 years; 18 pts were male, 13 were female. By the data cutoff date (May 31, 2022), 29 pts discontinued (26 due to disease progression, 3 due to adverse events). 8 Pts had a partial response (PR); the ORR was 25.8% (95% CI 11.9–44.6). The median PFS was 2.69 months (95% CI 1.91–2.99). The median OS was 7.85 months (95% CI 4.47–not estimable). The 6-month OS rate was 61.3%; the 9-month OS rate was 44.7%. 30 Pts had ≥1 treatment-related TEAE, most commonly neutropenia (n = 24); 25 pts had at least 1 grade ≥3 treatment-related TEAE, most commonly neutropenia (n = 22). 16 Pts had ≥1 TEAE resulting in dose reduction of E7389-LF. 4 Pts had ≥1 TEAE resulting in withdrawal of E7389-LF or nivolumab, including asthma, cerebral hemorrhage, decreased appetite, pulmonary edema, and upper gastrointestinal hemorrhage (each n = 1). 29 Pts had an evaluable PD-L1 combined positive score (CPS); 5 of 20 pts (25.0%) with a CPS of < 5 and 2 of 9 (22.2%) with a CPS of ≥5 had a PR. Increases in pharmacodynamic markers including vasculature-related markers were observed; antitumor immunity was observed per changes in interferon gamma (IFNγ) and IFNγ-related markers. Conclusions: E7389-LF 2.1 mg/m2 in combination with nivolumab 360 mg Q3W had promising efficacy for pretreated GC, as evidenced by the notable ORR of 25.8% as well as by PFS and OS. No new safety signals were identified for this combination. Biomarker changes suggested vascular remodeling activity and enhancement of antitumor immunity via IFNγ signaling. Clinical trial information: NCT04078295 .

A phase II study of preoperative chemotherapy with docetaxel, oxaliplatin, and S-1 followed by gastrectomy with D2 plus para-aortic nodal dissection for gastric cancer with extensive lymph node metastasis: JCOG1704

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Background: Prognosis of gastric cancer (GC) with extensive lymph node metastasis (ELM) is poor due to unresectability even without distant metastases. We conducted a phase II study to evaluate the safety and efficacy of preoperative chemotherapy with docetaxel (D), oxaliplatin (O), and S-1 (S) followed by extended gastrectomy. Methods: Eligibility criteria included histologically proven adenocarcinoma of the stomach; bulky nodal involvement around major branched arteries to the stomach (Bulky N) and/or para-aortic nodal metastases (PAN); cM0 (except para-aortic nodes); negative lavage cytology; not linitis plastica type; PS of 0 or 1; 20-75 years old. Patients received three 21-day cycles of preoperative chemotherapy of D (40 mg/m2 on day 1), O (100 mg/m2 on day 1), and S (80-120 mg /body from day 1 to day 14), and then underwent gastrectomy with D2 plus para-aortic nodal dissection. After surgery, patients received adjuvant chemotherapy with S-1 for 1 year. Primary endpoint was major pathological response rate, defined by the disappearance of more than two-thirds of the primary tumor. Expected and threshold value of major pathological response was set at 40% and 25%, respectively. Sample size was calculated to be 50 based on a one-sided alpha of 0.1, power of 0.8 and single-arm phase II study using a Southwest Oncology Group (SWOG) two-stage design. Results: Between Oct 2018 and Mar 2022, 47 patients were enrolled, of whom 46 were eligible for efficacy analysis. The median age was 67 years. The pathological type was differentiated in 33 patients and undifferentiated in 14. Twenty patients had only bulky N, 17 had only PAN, and 10 had both of bulky N and PAN. Clinical stage was III in 19 and IV in 28 patients. Except one patient refused chemotherapy, 46 patients (45 in three cycles and 1 in one cycle) completed preoperative DOS. Forty-four patients (94%) underwent gastrectomy, including 23 distal gastrectomy and 21 total gastrectomy, and 43 (91%) had an R0 resection. Major pathological response was confirmed in 26 of 46 patients (57% with 80% CI: 46-67), including pCR of 24%, which met the statistical significance (p<0.0001). According to the Becker’s criteria, grade 3 was 13, grade 2 was 12, grade 1b was 7, and grade 1a was 11. DOS-related grade 3/4 toxicities included neutropenia in 11 patients (24%), anorexia in 7 (16%), diarrhea in 4 (9%), and febrile neutropenia in 4 (9%). Surgery-related grade 3/4 toxicities were abdominal abscess in 5 (12%) and pancreatic fistula in 3 (7%). No treatment-related death was observed. Conclusions: Preoperative DOS followed by gastrectomy with D2 plus para-aortic nodal dissection is safe, feasible, and effective for GC with ELM. Clinical trial information: jRCTs031180028 .

Preoperative Comprehensive Geriatric Assessment Predicts Postoperative Risk in Older Patients with Esophageal Cancer

BACKGROUND

Preoperative risk assessment is important in older patients because they often have comorbidities and impaired organ function. We performed preoperative comprehensive geriatric assessment (CGA) for older patients with esophageal cancer.

PATIENTS AND METHODS

A total of 217 patients over 75 years old who underwent esophagectomy for thoracic esophageal cancer were analyzed. The CGA was performed preoperatively and included the Mini-Mental State Examination (MMSE), Geriatric Depression Score (GDS), vitality index, Barthel index, and instrumental activities of daily living (IADL). We defined the robust group as patients with normal function on every instrument, and the pre-frail and frail groups as those with functional impairment on one instrument or two or more instruments, respectively. We assessed how the CGA correlated with postoperative complications and prognosis.

RESULTS

Of the 217 patients, 86 (39.6%) were in the robust group, 68 (31.3%) in the pre-frail group, and 63 (29.0%) in the frail group. Postoperative pneumonia (P = 0.026) and anastomotic leakage (P = 0.032) were significantly more common in the frail group. The frail group had a significantly longer postoperative hospitalization period (P = 0.016) and significantly lower rate of discharge to home (P = 0.016). Overall survival (OS) was significantly worse in the frail group (5-year overall survival rate, frail group versus others, 37.8% versus 52.0%, P = 0.046), but it was not significant on multivariate analysis.

CONCLUSIONS

The preoperative CGA in older patients with esophageal cancer was associated with risk of postoperative complications.

Single-arm phase II trial to evaluate the safety of laparoscopic/robotic total gastrectomy with spleen-preserving splenic hilar dissection for locally advanced proximal gastric cancer that invades the greater curvature: JCOG1809

TPS479

Background: The standard treatment for locally advanced proximal gastric cancer invading the greater curvature is “open total gastrectomy combined with splenectomy” (OTG+S) aiming for whole clearance of the splenic hilar lymph nodes. However, its pertinent postoperative severe complication (e.g. pancreatic fistula) is problematic. An objective of this study is to evaluate the safety of “laparoscopic or robotic total gastrectomy with spleen-preserving splenic hilar dissection” (LRSHD) as a new treatment option which has a potential to reduce surgical morbidity, subsequently to replace the current standard treatment, OTG+S. Methods: This is a multicenter single-arm phase II trial. The main eligibility criteria are as follows; clinical T2-4a resectable locally advanced proximal gastric adenocarcinoma that invades the greater curvature; without obvious lymph node metastasis at the splenic hilum nor direct invasion to the spleen/splenogastric ligament. Protocol treatment is laparoscopic or robotic total gastrectomy with splenic hilar lymph node dissection (D2 + No.10 lymphadenectomy according to the Japanese guidelines) in which the spleen is preserved with skeletonizing the splenic vessels. Quality control of surgery is assured by surgeon’s qualification and central peer review of intraoperative photo at the splenic hilum after dissection. The primary endpoint is the proportion of postoperative pancreatic fistula and/or intra-abdominal abscess formation with Clavien-Dindo Grade III or higher (within 30 days after surgery). Secondary endpoints are intraoperative blood loss, operation time, mortality, overall postoperative complication, number of yield splenic hilar nodes, number of metastatic splenic hilar nodes, conversion to splenectomy, conversion to laparotomy, relapse-free survival, and overall survival. Sample size was set as 85 patients to obtain 80% power considering that 15% of patients are judged as unresectable intraoperatively, with the hypothesis that the primary endpoint would have an expected value of 7% and a threshold value of 16% in one-sided alpha of 0.1. Planned accrual period is 5 years. The accrual began in August 2019. As of August 2022, 53 of the planned 85 patients (62.4%) have been enrolled. When the safety of LRSHD is proved by this study, a non-inferiority phase III trial will be consequently launched. Clinical trial registry number: UMIN000037580. Clinical trial information: UMIN000037580 .

The impact of postoperative blood glucose levels on complications and prognosis after esophagectomy in patients with esophageal cancer

PURPOSE

This study aimed to characterize postoperative blood glucose fluctuation in patients who underwent esophagectomy for esophageal cancer, and to define its impact on complications and prognosis.

METHODS

The subjects of this retrospective study were 284 patients who underwent esophagectomy at Osaka University Hospital between 2015 and 2017. Data analyzed included clinicopathological background, the immediate postoperative blood glucose level (IPBG), postoperative blood glucose variability (PBGV), insulin dosage, postoperative complications, and prognosis.

RESULTS

The median IPBG and PBGV were 170 (64-260) mg/dl and 64.5 (11-217) mg/dl, respectively. Postoperative pneumonia was more common in patients with PBGV > 100 mg/dl (P = 0.015). Patients with IPBG < 170 mg/dl had significantly worse 5-year overall survival (OS) and 5-year recurrence-free survival (RFS) than those with IPBG > 170 mg/dl (54.5% vs. 80.4%, respectively, [P < 0.001] and 44.3% vs. 69.3%, respectively, [P = 0.001]). The 5-year OS rates were 43.5%, 68.3%, 80.6%, and 79.0% for patients with IPBG < 154, 154-170, 170-190, and ≥ 190 mg/dl, respectively. The corresponding 5-year RFS rates were 38.1%, 52.4%, 77.0%, and 61.3%, respectively. Multivariate analysis revealed that IPBG < 154 mg/dl and pathological stage were independent poor prognostic factors for OS.

CONCLUSION

PBGV was associated with postoperative pneumonia, and low IPBG was an independent poor prognostic factor for patients with esophageal cancer.

Laparoscopic resection for recurrent gastrointestinal stromal tumors and paraganglioma in a patient with Carney-Stratakis syndrome: A case report

Carney-Stratakis syndrome (CSS) is a familial syndrome characterized by gastrointestinal stromal tumors (GISTs) and paragangliomas, often at multiple sites. A 34-year-old woman who had undergone resection of gastric GISTs, liver metastases, and a retroperitoneal paraganglioma in her previous hospital was referred to our hospital due to recurrence after 5 years. She presented with two gastric GISTs, a liver tumor, and a peritoneal tumor. As molecular-targeted agents are reported to be ineffective against CSS-related GISTs, we selected surgical resection for the recurrence. We performed laparoscopic local gastrectomy, liver S7 subsegmentectomy, and peritoneal tumor resection. Pathological findings revealed multiple gastric GISTs with liver metastasis and a paraganglioma. The laparoscopic approach could be performed safely, less invasively, and it could be more effective in such cases. This is the first case report of laparoscopic resection for recurrent CSS-related GISTs and paragangliomas.

Mechanism underlying lens fogging and its countermeasure in laparoscopic surgery

BACKGROUND

During laparoscopic surgery, visualization is fogged due to the influence of temperature. Fogging on the laparoscopic lens heightens the difficulty of the procedure. Therefore, the aim of this study was to analyse thermodynamics in laparoscopy.

MATERIAL AND METHODS

A temperature sensor was attached to the laparoscopic tip and the abdominal cavity of five swine under general anaesthesia. The laparoscope was inserted into the abdominal cavity for five minutes after heating its tip with 65 °C saline for 10-300 s. The defogged laparoscope was wiped at room temperature for 10-300 s. Then, the laparoscope was inserted into the abdominal cavity for five minutes.

RESULTS

The temperature five minutes after insertion was similar for the 10-300 s heating durations (approximately 32.0 °C). There was no fogging when the laparoscope was wiped for 10-30 s. Two fogging events occurred when it was wiped for 60 s (temperature difference: -3.5 °C, -4.6 °C). Five fogging events were observed immediately after insertion when it was wiped for 300 s.

CONCLUSION

This study showed that the heating time was more than ten seconds to prevent fogging. We found that fogging occurred when the laparoscopic tip temperature was 3.5 °C lower than the abdominal cavity temperature.

Neutrophil-to-lymphocyte ratio after neoadjuvant chemotherapy as an independent prognostic factor in patients with esophageal squamous cell carcinoma

Studies have shown that neoadjuvant chemotherapy (NAC) followed by surgical resection improves the survival of patients with esophageal squamous cell carcinoma (ESCC), and that the neutrophil-to-lymphocyte ratio (NLR) nay be a prognostic biomarker in various types of cancer. Despite the noTable changes in the tumor and its microenvironment during NAC, it remains unclear how the NLR changes and which values (before or after NAC) best predict prognosis. The present study aimed to analyze changes in the NLR before and after NAC, and to determine which was a better prognostic factor. This study retrospectively analyzed 338 consecutive patients with ESCC who received NAC followed by curative resection. NLRs before (pre-NLR) and after (post-NLR) NAC were calculated, after which the impact of NAC on NLR, overall survival (OS) and recurrence-free survival (RFS), as well as the relationship between hematological toxicities and NLR, was evaluated. Cutoff values for pre- and post-NLR were 3.7 and 2.5, respectively. Patients with high post-NLR had a worse OS (P=0.0001) and 3-year RFS (P=0.03) than those with low post-NLR. Multivariate analysis identified high post-NLR, pN1 and clinical response as independent prognostic factors. In conclusion, post-NLR was revealed as a better prognostic factor than pre-NLR for patients receiving NAC followed by surgical resection.

Five-year follow-up of a randomized clinical trial comparing bursectomy and omentectomy alone for resectable gastric cancer (JCOG1001)

BACKGROUND

Bursectomy, the total resection of the bursa omentalis, is a standard procedure in gastrectomy for resectable gastric cancer. A phase III trial (JCOG1001) comparing bursectomy and omentectomy alone was terminated early at the interim analysis. The final results of the updated analysis after a minimum follow-up of 5 years are reported here.

METHODS

Patients with histologically proven adenocarcinoma of the stomach (cT3-T4a) were randomized (1 : 1) during surgery to bursectomy or omentectomy-alone groups and then underwent D2 gastrectomy. The primary endpoint was overall survival, analysed on an intention-to-treat basis.

RESULTS

A total of 1204 patients (602 bursectomy and 602 omentectomy alone) were enrolled between June 2010 and March 2015. The bursectomy group had a significantly higher incidence of Clavien-Dindo grade III-IV intra-abdominal abscess than the omentectomy-alone group (5.5 versus 2.5 per cent respectively; P = 0.008). The updated 5-year overall survival rates were 74.9 (95 per cent c.i. 71.2 to 78.2) per cent in the bursectomy group and 76.5 (72.8 to 79.7) per cent in the omentectomy-alone group; the adjusted HR for death in the bursectomy group was 1.03 (95 per cent c.i. 0.83 to 1.27) (1-sided P = 0.598). Bursectomy did not decrease peritoneal recurrence (12.1 versus 12.3 per cent respectively; P = 1.000). In a multivariable analysis, old age (above 65 years), tumour located in the lower third or posterior wall of the stomach, macroscopic type 3/5, total gastrectomy, and cT4a were independent predictors of poor overall survival, but omentectomy alone was not.

CONCLUSION

In D2 gastrectomy, bursectomy is not recommended as a standard procedure for cT3-T4a gastric cancer. Registration number: UMIN000003688 (https://www.umin.ac.jp/ctr/).

Phase I study of the irreversible fibroblast growth factor receptor 1-4 inhibitor futibatinib in Japanese patients with advanced solid tumors

This phase I study was designed to: (1) determine the maximum tolerated dose (MTD) and recommended dose (RD) of the fibroblast growth factor receptor (FGFR) inhibitor futibatinib in Japanese patients with advanced solid tumors, and (2) examine the antitumor activity of the RD in patients with gastric cancer (GC) or other advanced solid tumors who have FGFR or FGF/FGFR abnormalities, respectively. In the dose-escalation phase, patients were assigned to 21-day cycles of oral futibatinib 8-160 mg three times a week (TIW) or 16 or 20 mg once daily (QD). In the expansion phase, patients received oral futibatinib 56, 80, or 120 mg TIW, or 16 or 20 mg QD. Eighty-three patients received futibatinib TIW (n = 40) or QD (n = 43). No dose-limiting toxicities were observed according to the final study protocol definition, and the MTD was not reached. The most common adverse events with both regimens were hyperphosphatemia (TIW, 82.5%; QD, 100.0%) and decreased appetite (TIW, 40.0%; QD, 58.1%). Hyperphosphatemia was asymptomatic, not leading to futibatinib discontinuation. The overall response rate (ORR) was 11.5% in patients with FGF/FGFR abnormalities. Notably, in GC patients harboring FGFR2 copy number (CN) ≥10, the ORR was 36.4% versus 0 in patients with CN <10. Therefore, futibatinib had a generally predictable and manageable safety profile in patients with advanced solid tumors. Antitumor activity was seen in patients with FGF/FGFR abnormalities, particularly those with GC and high FGFR2 CNs. Thus, futibatinib 20 mg QD was chosen as the RD for phase II studies.

[Experience with Thoracoscopic and Endoscopic Cooperative Surgery for Gastric Tube Cancer after Thoracic Esophagectomy]

Surgical treatment of gastric tube cancer after thoracic gastrectomy is highly invasive, especially for gastric tube cancer of the posterior mediastinal tract, and in some cases, a reduction surgery is an option. We have experienced 4 cases of posterior mediastinal reconstructive gastric tube cancer in which local resection by thoracoscopic and endoscopic cooperative surgery( TECS)was conducted. All cases had undergone video-assisted thoracoscopic subtotal esophagectomy and posterior mediastinal gastric tube reconstruction for thoracic esophageal cancer. In 1 case, endoscopic submucosal dissection was performed, but it showed positive for vertical margins. Other cases were not indicated for endoscopic resection. Considering the patient's background, we decided to preserve the gastric tube and planned local resection by TECS. One patient was transferred to open thoracotomy due to severe adhesion, and 1 patient underwent segmental resection and 2-stage reconstruction due to narrowing of the gastric tube lumen at the suture closure. In all cases, the resection margins were negative and the patients are alive without recurrence of gastric tube cancer. Local resection of gastric tube with TECS for posterior mediastinal tract reconstructive gastric tube cancer may be useful as a less invasive surgical treatment.

[A Case of Gastric Cancer with Peripancreatic Aneurysm Treated with Embolization before Gastrectomy]

An 81-year-old man was admitted to our hospital with a 24-mm peripancreatic aneurysm and occlusion of the celiac artery on abdominal contrast-enhanced CT for preoperative screening of gastric cancer. Angiography showed severe stenosis at the origin of the celiac artery and an aneurysm in the anterior superior pancreaticoduodenal artery for which coil embolization was performed. The patient underwent laparoscopic distal gastrectomy on the 6th day post-embolization. Intraoperative ICG fluorescence confirmed good blood flow into the liver and residual stomach. The patient had a good postoperative course and was discharged on postoperative day 10. He has been recurrence-free for 10 months postoperative. Abdominal visceral aneurysms are at high risk of rupture and should be treated, but the presence of an aneurysm in the surgical site increases the risk further and requires treatment. A preoperative vascular evaluation and aneurysmal embolization in the abdominal region, as in this case, may help reduce intraoperative and postoperative risks.

TRESBIEN (OGSG 2101): encorafenib, binimetinib and cetuximab for early recurrent stage II/III BRAF V600E-mutated colorectal cancer

The BRAF V600E mutation accounts for approximately 5% of colorectal cancer (CRC) cases and is an extremely poor prognostic factor. However, there are no clear recommendations regarding first-line therapy for patients with early recurrent BRAF V600E-mutated CRC, during or after adjuvant chemotherapy. Recently, a novel combination of encorafenib, binimetinib and cetuximab, showed a higher response rate than standard chemotherapy in patients with BRAF V600E-mutated CRC. Here we describe our plan for the TRESBIEN study (OGSG 2101), which is an open-label, multicenter, single-arm, phase II study designed to evaluate whether encorafenib, binimetinib and cetuximab are effective for patients with early recurrent BRAF V600E-mutated colorectal cancer, during or after adjuvant chemotherapy. The planned number of subjects is 25.

Neoadjuvant docetaxel, oxaliplatin and S-1 therapy for the patients with large type 3 or type 4 gastric cancer (OGSG1902): protocol of a multi-center, phase II study

Background

Large type 3 and type 4 gastric cancers have extremely poor prognoses. To address this, neoadjuvant chemotherapy may be a promising approach. The phase III JCOG0501 study, conducted to confirm the superiority of neoadjuvant S-1 plus cisplatin followed by D2 gastrectomy over upfront surgery, showed no survival benefit for neoadjuvant S-1 plus cisplatin. In Korea, the PRODIGY study, which was a phase III study of neoadjuvant docetaxel plus oxaliplatin plus S-1 (DOS) followed by surgery and adjuvant S-1 versus surgery and adjuvant S-1 for gastric cancer of T2-3N+ or T4Nany, showed that progression-free survival (PFS) was significantly superior in the neoadjuvant DOS arm. Therefore, DOS therapy may be a promising candidate for preoperative chemotherapy for large type 3 or type 4 gastric cancer.

Methods

Preoperative docetaxel 40 mg/m² and oxaliplatin 100 mg/m² will be intravenously administered on day1 every three weeks. S-1 will be orally administered 80 mg/m² on days 1–14 of a 21-day cycle. Patients will receive three courses of treatment and gastrectomy with ≥D2 lymph node dissection. Postoperative S-1 plus docetaxel therapy (DS) will be administered according to the JACCRO GC-07 (START-2) study. The primary endpoint is the 3-year PFS rate. Secondary endpoints include PFS time, overall survival time, pathological response rate, response rate according to RECIST version1.1, proportion of completion of neoadjuvant chemotherapy, R0 resection rate, proportion of completion of surgery, proportion of completion of protocol treatment, proportion of negative conversion of CY, adverse event occurrence rate, and nutritional evaluation. The null hypothesis for the 3-year PFS rate is 45% and the expected value is 60%. The total sample size is 46 considering that the registration period and follow-up period are two and three years, respectively.

Discussion

This is a prospective, multicenter, single-arm, open-label, phase II trial assessing the efficacy and safety of preoperative DOS and postoperative DS for large type 3 or type 4 gastric cancer. The results will inform future phase III trials and are expected to lead to new treatment strategies for large type 3 or type 4 gastric cancer.

Trial registration

Registered with Japan Registry of Clinical Trials on October 11, 2019 (jRCTs051190060).

Histology Classification Highlights Differences in Efficacy of S-1 versus Capecitabine, in Combination with Cisplatin, for HER2-Negative Unresectable Advanced or Recurrent Gastric Cancer with Measurable Disease

It has been suggested that the therapeutic efficacy of S-1 + cisplatin (SP) and capecitabine + cisplatin (XP) may differ depending on the histology of the tumor, but no clear evidence exists. Individual participant data were obtained from three randomized phase II trials in which such patients received either SP (S-1 [40-60 mg twice daily for 21 days] plus cisplatin [60 mg/m² on day 8], every 5 weeks) or XP (capecitabine [1000 mg/m² twice daily for 14 days] plus cisplatin [80 mg/m² on day 1], every 3 weeks). A total of 162 patients were included, with 79 patients in the SP arm and 83 patients in the XP arm. Although there was also no difference between arms in ORR according to histological classification, differentiated tumors showed a significantly better OS (but not PFS) for SP versus XP that was associated with a deeper tumor shrinkage. Undifferentiated tumors showed a consistently better OS, and PFS for SP versus XP, likely because cases without tumor shrinkage tended to be fewer for SP. Our data thus showed that SP was superior to XP in this setting, but there were qualitative differences in therapeutic efficacy dependent on tumor histology.

Efficacy of electrocoagulation hemostasis: a study on the optimal usage of the very-low-voltage mode

BACKGROUND

The very-low-voltage (VLV) mode in electrosurgery can stably and deeply energize tissues even if the local electrical resistance changes with energization. Therefore, in electrosurgical hemostasis, the VLV mode is more reliable than other coagulation modes. In clinical practice, the appropriate use of combined saline drip and blood suction under the VLV mode can further enhance coagulation ability. However, the detailed mechanism is not known. The current study aimed to evaluate the association between electrosurgical activation time (ET) and hemostatic tissue effect (HTE) under the VLV mode. Further, the effect of saline drip and suction on power consumption and HTE was validated.

METHODS

Twelve female pigs weighing 35 kg were included in the experiment. A liver hemorrhage model was established via an open abdominal procedure, and hemostasis in the hemorrhagic lesion was attempted using the VLV mode under different conditions (ET: 3, 6, 9, and 12 s, with/without saline drip and/or continuous suction). Electrical data (such as voltage, current, and resistance) during coagulation were extracted. Then, the vertical/horizontal extent of HTE was assessed, and the hemostasis outcome (successful or failed) was recorded.

RESULTS

The vertical/horizontal HTE, power consumption, and integrated current value were positively correlated with the ET. The coagulation depth deepened with saline drip (p < 0.01). However, it was not affected by continuous suction (p = 0.20). The HTE area increased with saline drip (p < 0.01) and decreased with suction (p < 0.01). The power consumption and integrated current increased with saline drip (p < 0.01) and decreased with suction (p < 0.01). The success rate of hemostasis decreased with saline drip alone (31of 48 trials [success rate = 64.5%] in the saline drip group and 44/48 trials (success rate = 91.7%) in the control group). However, it improved with continuous suction (46/48 trials [success rate = 95.8%]).

CONCLUSION

The electrosurgical activation time was positively correlated with hemostatic tissue effect. Saline drip increased heat transfer efficiency but decreased the success rate of hemostasis. Therefore, the use of continuous suction in addition to saline drip increased hemostatic efficiency.

Phase 2 trial of neoadjuvant docetaxel, oxaliplatin, and S‐1 for clinical stage III gastric or esophagogastric junction adenocarcinoma

Background

Although perioperative treatment has been the standard of care for resectable gastric cancer in the West, postoperative adjuvant chemotherapy is still the standard in Japan. We conducted the first phase 2 trial to investigate the efficacy and safety of neoadjuvant docetaxel, oxaliplatin, and S-1 (DOS) chemotherapy for cStage III gastric or esophagogastric junction (EGJ) adenocarcinoma in Japan.

Methods

Eligibility criteria included cStage III adenocarcinoma of the stomach or EGJ. Patients received docetaxel (40 mg/m², day 1), oxaliplatin (100 mg/m², day 1), or S-1 (80 mg/m², days 1-14) during a 3-week cycle. After two or three cycles of DOS, patients underwent surgical resection. The primary endpoint was progression-free survival (PFS).

Results

Between June 2015 and March 2019, 50 patients were enrolled from four institutions. Of 48 eligible patients (37 gastric and 11 EGJ adenocarcinoma), 42 (88%) completed two or three DOS cycles. Grade 3-4 neutropenia and diarrhea occurred in 69% and 19% of patients, respectively, but there were no treatment-related deaths. R0 resection was achieved in 44 (92%) patients, and the pathological response rate (≥ grade 1b) was 63% (30/48). The 3-year PFS, overall survival, and disease-specific survival rates were 54.2%, 68.7%, and 75.8%, respectively.

Conclusion

Neoadjuvant DOS chemotherapy had a sufficient antitumor effect and tolerable safety profile in patients with gastric or EGJ adenocarcinoma. The survival benefit of a neoadjuvant strategy using our DOS regimen should be validated in phase 3 trials.

Early postoperative weight loss is associated with poor prognosis in patients with esophageal cancer

BACKGROUND

Surgery for esophageal cancer (EC) causes morphological and functional changes in the upper gastrointestinal tract, resulting in postoperative weight loss (PWL). PWL has been shown to lead to poor nutritional status and immunocompetence, which may worsen the prognosis for several types of cancer. However, few reports have examined the relationship between weight loss (WL) in the early postoperative period and cancer prognosis.

METHODS

A total of 421 esophageal cancer patients underwent curative esophagectomy at Osaka University Hospital from 2010 to 2016. Based on the patients' body weight 1.5 months after surgery, they were classified into severe WL (n = 50) and slight-moderate WL (n = 371) groups.

RESULTS

The 5-year overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival (RFS) were significantly lower in the severe WL group than the slight-moderate WL group (p = 0.0002, p < 0.0001, and p = 0.0004, respectively). In the multivariate analysis, tumor invasion depth (pT3, 4), lymph node metastasis (pN2, 3), preoperative Prognostic Nutrition Index (< 45), postoperative complications (≥ G3), and severe WL were independent prognostic factors for CSS (hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.7-3.7; HR 1.6, 95% CI 1.1-2.4; HR 1.9, 95% CI 1.3-2.8; HR 1.6, 95% CI 1.1-2.4; and HR 2.7, 95% CI 1.7-4.2, respectively). In a multivariate analysis of risk factors leading to severe WL, thoracotomy (VATS) and postoperative MAX CRP (high) were independent risk factors (odds ratio [OR 0.48, 95% CI 0.24-0.97; OR 1.9, 95% CI 1.0-3.5).

CONCLUSION

Early PWL would be a useful marker of poor cancer prognosis in EC patients. Highly inflammatory conditions due to surgical invasion and postoperative complications may contribute to early PWL.

A phase II study of S-1 therapy for patients with advanced and recurrent esophageal cancer resistant or intolerable to fluorouracil, platinum, and taxane therapy (OGSG 1404)

BACKGROUND

Fluorouracil (FU), platinum (PT), and taxane (TAX) therapy was the standard chemotherapy for esophageal squamous cell carcinoma (ESCC) before the era of anti-programmed death-1 antibodies. The aim of this phase II trial was to evaluate the efficacy and safety of S-1 monotherapy for patients with recurrent or metastatic (R/M) ESCC resistant or intolerable to FU, PT, and TAX therapy.

METHODS

Eligible patients had R/M ESCC; no prior S-1 use; were intolerant or refractory to prior FU, PT, and TAX therapy; aged ≧ 20 years; and Eastern Cooperative Oncology Group performance status 0 or 1. S-1 was administered orally from days 1 to 28, every 6 weeks until disease progression. The primary endpoint was the disease control rate (DCR) for each patient, assessed by Response Evaluation Criteria in Solid Tumors, version 1.1. Secondary endpoints were overall survival, progression-free survival, time to treatment failure, response rate, and toxicity.

RESULTS

Between October 2015 and December 2017, 17 patients were recruited, and the trial was terminated because of slow accrual. The DCR was 46.7%. The response rate was 13.3%. The median progression-free survival was 2.0 months. The median time to treatment failure was 1.9 months. The median overall survival was 8.4 months, and the 1 year overall survival rate was 30.5%.

CONCLUSIONS

Although this trial closed early because of slow accrual, we observed modest clinical activity with S-1 in patients with R/M ESCC who could not tolerate or whose tumors were refractory to FU, PT, and TAX therapy.

Translation from manual to automatic endoscopic insufflation enhanced by a pressure limiter

BACKGROUND

Optimal visualization and safety have always been essential in performing any type of endoscopic surgery. However, the safety of automatic gastrointestinal (GI) insufflation has yet to be thoroughly studied, especially when combined with manual insufflation. The current study aimed to verify whether the pressure limiter could lower GI endoluminal pressure during endoscopic procedures and affect the behavioral patterns of endoscopists.

METHODS

A preclinical blinded trial was conducted on endoscopists who had no knowledge regarding the presence of the pressure limiter that prevents a GI endoluminal pressure above 25 mmHg. Endoscopists in group A performed esophageal endoscopic submucosal dissection (ESD) with our insufflation device equipped with the pressure limiter, whereas those in group B performed the same procedure without the pressure limiter. During all procedures, endoluminal pressure was continuously monitored. The primary endpoint of the current study was to measure the endoluminal pressure with or without the pressure limiter during esophageal ESD, while the secondary endpoint was to evaluate the effect of the pressure limiter on intraesophageal pressure and perioperative outcomes during esophageal ESD. A questionnaire survey was conducted after each session.

RESULTS

A total of 79 endoscopists were included in this randomized control study. Group A had significantly lower endoluminal pressure than group B (10.6 ± 4.61 vs. 16.25 ± 7.51 mmHg, respectively; p < 0.05). Although two pigs in group B died from tension pneumothorax, none in group A died. Evaluation of lumen expansion, ease of aspiration, and visual field reproducibility were poorer in group A than in group B, although all fell within the acceptable range. Subjective evaluation of usability was divided into two categories, Excellent/Good and Poor/Bad, with no significant differences in any of the items.

CONCLUSIONS

This preclinical study showed that endoscopic treatment with an automatic insufflation system could be performed at lower endoluminal pressure with a pressure limiter, which had no adverse effects on the endoscopist's feels on endoscopic procedures with the device.