Localized colorectal cancer database integrating 4 randomized controlled trials; (JCOG2310A)

Although phase III randomized controlled trials (RCTs) represent the most robust statistical approach for answering clinical questions, they require massive expenditures in terms of time, labor, and funding. Ancillary and supplementary analyses using RCTs are sometimes conducted as alternative approaches to answering clinical questions, but the available integrated databases of RCTs are limited. In this background, the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG) established a database of ancillary studies integrating four phase III RCTs (JCOG0212, JCOG0404, JCOG0910 and JCOG1006) conducted by the CCSG to investigate specific clinicopathological factors in pStage II/III colorectal cancer (JCOG2310A). This database will be updated by adding another clinical trial data and accelerating several analyses that are clinically relevant in the management of localized colorectal cancer. This study describes the details of this database and planned and ongoing analyses as an initiative of JCOG cOlorectal Young investigators (JOY).

Prognostic Impact of Post-operative Infectious Complications in Gastric Cancer Patients Receiving Neoadjuvant Chemotherapy: Post Hoc Analysis of a Randomized Controlled Trial, JCOG0501

PURPOSE

Post-operative infectious complication (IC) is a well-known negative prognostic factor, while showing neoadjuvant chemotherapy (NAC) may cancel out the negative influence of IC. This analysis compared the clinical impacts of IC according to the presence or absence of NAC in gastric cancer patients enrolled in the phase III clinical trial (JCOG0501) which compared upfront surgery (arm A) and NAC followed by surgery (arm B) in type 4 and large type 3 gastric cancer.

METHODS

The subjects were 224 patients who underwent R0 resection out of 316 patients enrolled in JCOG0501. The prognoses of the patients with or without ICs in each arm were investigated by univariable and multivariable Cox regression analyses.

RESULTS

There were 21 (20.0%) IC occurrences in arm A and 15 (12.6%) in arm B. In arm A, the overall survival (OS) of patients with ICs was slightly worse than those without IC (3-year OS, 57.1% in patients with ICs, 79.8% in those without ICs; adjusted hazard ratio (95% confidence interval), 1.292 (0.655-2.546)). In arm B, patients with ICs showed a trend of better survival than those without ICs (3-year OS, 80.0% in patients with IC, 74.0% in those without IC; adjusted hazard ratio, 0.573 (0.226-1.456)).

CONCLUSION

This study could not indicate the negative prognostic influence of ICs in gastric cancer patients receiving NAC, which might be canceled by NAC. To build exact evidence, further investigation with prospective and large numbers of data might be expected.

Early endpoints of a randomized phase II trial of preoperative chemotherapy with S-1/CDDP with or without trastuzumab followed by surgery for HER2-positive resectable gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis: Japan Clinical Oncology Group study JCOG1301C (Trigger Study)

BACKGROUND

This randomized phase II study explored the superiority of trastuzumab plus S-1 plus cisplatin (SP) over SP alone as neoadjuvant chemotherapy (NAC) for HER2-positive resectable gastric cancer with extensive lymph node metastasis.

METHODS

Eligible patients with HER2-positive gastric or esophagogastric junction cancer and extensive lymph node metastasis were randomized to receive three or four courses of preoperative chemotherapy with SP (arm A) or SP plus trastuzumab (arm B). Following gastrectomy, adjuvant chemotherapy with S-1 was administered for 1 year in both arms. The primary endpoint was overall survival, and the sample size was 130 patients in total. The trial is registered with the Japan Registry of Clinical Trials, jRCTs031180006.

RESULTS

This report elucidates the early endpoints, including pathological findings and safety. The study was terminated early due to slow patient accruals. In total, 46 patients were allocated to arm A (n = 22) and arm B (n = 24). NAC was completed in 20 patients (91%) in arm A and 23 patients (96%) in arm B, with similar incidences of grade 3-4 hematological and non-hematological adverse events. Objective response rates were 50% in arm A and 84% in arm B (p = 0·065). %R0 resection rates were 91% and 92%, and pathological response rates (≥ grade 1b in Japanese classification) were 23% and 50% (p = 0·072) in resected patients, respectively.

CONCLUSIONS

Trastuzumab can be safely added to platinum-containing doublet chemotherapy as NAC, and it has the potential to contribute to higher antitumor activity against locally advanced, HER2-positive gastric or esophagogastric junction cancer with extensive nodal metastasis.

Short-term outcomes of preoperative chemotherapy with docetaxel, oxaliplatin, and S-1 for gastric cancer with extensive lymph node metastasis (JCOG1704)

BACKGROUND

The prognosis for marginally resectable gastric cancer with extensive lymph node metastasis (ELM) remains unfavorable, even after R0 resection. To assess the safety and efficacy of preoperative docetaxel, oxaliplatin, and S-1 (DOS), we conducted a multicenter phase II trial.

METHODS

Eligibility criteria included histologically proven HER2-negative gastric adenocarcinoma with bulky nodal (bulky N) involvement around major branched arteries or para-aortic node (PAN) metastases. Patients received three cycles of docetaxel (40 mg/m2, day 1), oxaliplatin (100 mg/m2, day 1), and S-1 (80-120 mg/body, days 1-14), followed by gastrectomy with D2 plus PAN dissection. Subsequently, patients underwent postoperative chemotherapy with S-1 for 1 year. The primary endpoint was major (grade ≥ 2a) pathological response rate (pRR) according to the Japanese Classification of Gastric Carcinoma criteria.

RESULTS

Between October 2018 and March 2022, 47 patients (bulky N, 20; PAN, 17; both, 10) were enrolled in the trial. One patient was ineligible. Another declined any protocol treatments before initiation. Among the 45 eligible patients who initiated DOS chemotherapy, 44 (98%) completed 3 cycles and 42 (93%) underwent R0 resection. Major pRR and pathological complete response rates among the 46 eligible patients, including the patient who declined treatment, were 57% (26/46) and 24% (11/46), respectively. Common grade 3 or 4 toxicities were neutropenia (24%), anorexia (16%), febrile neutropenia (9%), and diarrhea (9%). No treatment-related deaths occurred.

CONCLUSIONS

Preoperative chemotherapy with DOS yielded favorable pathological responses with an acceptable toxicity profile. This multimodal approach is highly promising for treating gastric cancer with ELM.

Risk factors for abdominal surgical infectious complications after distal gastrectomy for gastric cancer: A post-hoc analysis of a randomized controlled trial (JCOG0912)

BACKGROUND

Abdominal surgical infectious complications (ASIC) after gastrectomy for gastric cancer impair patients' survival and quality of life. JCOG0912 was conducted to compare laparoscopy-assisted distal gastrectomy with open distal gastrectomy for clinical stage IA or IB gastric cancer. The present study aimed to identify risk factors for ASIC using prospectively collected data.

METHODS

We performed a post-hoc analysis of the risk factors for ASIC using the dataset from JCOG0912. All complications were evaluated according to the Clavien-Dindo classification (CD). ASIC was defined as CD grade I or higher anastomotic leakage, pancreatic fistula, abdominal abscess, and wound infection. Analyses were performed using the logistic regression model for univariable and multivariable analyses.

RESULTS

A total of 910 patients were included (median age, 63 years; male sex, 61 %). Among them, ASIC occurred in 5.8 % of patients. In the univariable analysis, male sex (odds ratio [OR] 2.855, P = 0.003), diabetes (OR 2.565, P = 0.029), and Roux-en-Y (R-Y) reconstruction (vs. Billroth Ⅰ, OR 2.707, P = 0.002) were significant risk factors for ASIC. In the multivariable analysis, male sex (OR 2.364, P = 0.028) and R-Y reconstruction (vs. Billroth Ⅰ, OR 2.310, P = 0.015) were independent risk factors for ASIC.

CONCLUSIONS

Male sex and R-Y reconstruction were risk factors for ASIC after distal gastrectomy. Therefore, when performing surgery on male patients or when R-Y reconstruction is selected after gastrectomy for gastric cancer, surgeons should pay special attention to prevent ASIC.

A multi-institutional randomized phase III study comparing minimally invasive distal pancreatectomy versus open distal pancreatectomy for pancreatic cancer; Japan Clinical Oncology Group study JCOG2202 (LAPAN study)

BACKGROUND

Minimally invasive distal pancreatectomy (MIDP), including laparoscopic and robotic distal pancreatectomy, has gained widespread acceptance over the last decade owing to its favorable short-term outcomes. However, evidence regarding its oncologic safety is insufficient. In March 2023, a randomized phase III study was launched in Japan to confirm the non-inferiority of overall survival in patients with resectable pancreatic cancer undergoing MIDP compared with that of patients undergoing open distal pancreatectomy (ODP).

METHODS

This is a multi-institutional, randomized, phase III study. A total of 370 patients will be enrolled from 40 institutions within 4 years. The primary endpoint of this study is overall survival, and the secondary endpoints include relapse-free survival, proportion of patients undergoing radical resection, proportion of patients undergoing complete laparoscopic surgery, incidence of adverse surgical events, and length of postoperative hospital stay. Only a credentialed surgeon is eligible to perform both ODP and MIDP. All ODP and MIDP procedures will undergo centralized review using intraoperative photographs. The non-inferiority of MIDP to ODP in terms of overall survival will be statistically analyzed. Only if non-inferiority is confirmed will the analysis assess the superiority of MIDP over ODP.

DISCUSSION

If our study demonstrates the non-inferiority of MIDP in terms of overall survival, it would validate its short-term advantages and establish its long-term clinical efficacy.

TRIAL REGISTRATION

This trial is registered with the Japan Registry of Clinical Trials as jRCT 1,031,220,705 [ https://jrct.niph.go.jp/en-latest-detail/jRCT1031220705 ].

Protocol digest of a randomized controlled adaptive Phase II/III trial of neoadjuvant chemotherapy for Japanese patients with oesophagogastric junction adenocarcinoma: Japan Clinical Oncology Group Study JCOG2203 (NEO-JPEG)

Treatment strategies for oesophagogastric junction adenocarcinoma have not been standardized despite its poor prognosis due to differences in the incidence rates between Western countries and Asia. This randomized Phase II/III trial was initiated in June 2023 to determine which neoadjuvant chemotherapy regimen, docetaxel, oxaliplatin and S-1 or fluorouracil, oxaliplatin and docetaxel, is a more promising treatment in Phase II and confirm the superiority of neoadjuvant chemotherapy with docetaxel, oxaliplatin and S-1 or fluorouracil, oxaliplatin and docetaxel followed by surgery and postoperative chemotherapy over upfront surgery and postoperative chemotherapy in terms of overall survival in patients with Clinical Stage III or IVA oesophagogastric junction adenocarcinoma in Phase III. A total of 460 patients, including 150 patients in Phase II and 310 patients in Phase III, are planned to be enrolled from 85 hospitals in Japan over 5 years. This trial has been registered in the Japan Registry of Clinical Trials as jRCTs031230182 (https://jrct.niph.go.jp/latest-detail/jRCTs031230182).

5-year follow-up results of a JCOG1104 (OPAS-1) phase III non-inferiority trial to compare 4 courses and 8 courses of S-1 adjuvant chemotherapy for pathological stage II gastric cancer

BACKGROUND

Postoperative adjuvant chemotherapy with S-1 for 1 year (corresponding to eight courses) is the standard treatment for pathological stage II gastric cancer. The phase III trial (JCOG1104) investigating the non-inferiority of four courses of S-1 to eight courses was terminated due to futility at the first interim analysis. To confirm the primary results, we reported the results after a 5-years follow-up in JCOG1104.

METHODS

Patients histologically diagnosed with stage II gastric cancer after radical gastrectomy were randomly assigned to receive S-1 for eight or four courses. In detail, 80 mg/m2/day S-1 was administered for 4 weeks followed by a 2-week rest as a single course.

RESULTS

Between February 16, 2012, and March 19, 2017, 590 patients were enrolled and randomly assigned to 8-course (295 patients) and 4-course (295 patients) regimens. After a 5-years follow-up, the relapse-free survival at 3 years was 92.2% for the 8-course arm and 90.1% for the 4-course arm, and that at 5 years was 87.7% for the 8-course arm and 85.6% for the 4-course arm (hazard ratio 1.265, 95% CI 0.846-1.892). The overall survival at 3 years was 94.9% for the 8-course arm, 93.2% for the 4-course arm, and that at 5 years was 89.7% for the 8-course arm, and 88.6% for the 4-course arm (HR 1.121, 95% CI 0.719-1.749).

CONCLUSIONS

The survival of the four-course arm was slightly but consistently inferior to that of the eight-course arm. Eight-course S-1 should thus remain the standard adjuvant chemotherapy for pathological stage II gastric cancer.

Clinical impact of skeletal muscle mass change during the neoadjuvant chemotherapy period in patients with gastric cancer: An ancillary study of JCOG1002

BACKGROUND

Recent studies have revealed that sarcopenia is associated with postoperative complications and poor prognosis. Although neoadjuvant chemotherapy is a promising treatment for gastric cancer, its toxicity may lead to the loss of skeletal muscle mass. This study investigates the changes in skeletal muscle mass during neoadjuvant chemotherapy and its clinical impact on patients with locally advanced gastric cancer.

METHODS

Fifty patients who completed two courses of neoadjuvant chemotherapy followed by surgery were included. Skeletal muscle mass was measured using computed tomography images before and after chemotherapy. The proportion of skeletal muscle mass change (%SMC) during neoadjuvant chemotherapy and its cutoff value was explored using the receiver operating characteristic for the overall survival of patients undergoing R0 resection. Risk factors of skeletal muscle mass loss were also evaluated.

RESULTS

Overall, 64% of patients had skeletal muscle mass loss during neoadjuvant chemotherapy (median %SMC -3.4%; range: -18.9% to 10.3%). Multivariable analysis identified older age (≥70 years) as an independent predictor of skeletal muscle mass loss (mean [95% confidence interval]: -4.70% [-8.83 to -0.58], p = 0.026). Among 43 patients undergoing R0 resection, %SMC <-6.9% was an independent poor prognostic factor for overall survival (hazard ratio, 11.53; 95% confidence interval, 2.78-47.80) and relapse-free survival (hazard ratio 4.54, 95% confidence interval 1.50-13.81).

CONCLUSIONS

Skeletal muscle mass loss occurs frequently during neoadjuvant chemotherapy for locally advanced gastric cancer and could adversely affect survival outcomes.

Association between the antiadhesion membrane and small bowel obstruction after open gastrectomy: A supplemental analysis of the randomized controlled JCOG1001 trial

Aim

Postoperative small bowel obstruction (SBO) is one of the major complications that is mainly caused by postoperative adhesion. Recently, the antiadhesion membrane has become popular for postoperative SBO prevention. However, its efficacy is yet to be confirmed in the gastric cancer surgery field. Here, we conducted the supplemental analysis of the randomized controlled trial JCOG1001 to investigate the efficacy of the antiadhesion membrane on SBO prevention in patients with open gastrectomy for gastric cancer.

Methods

Of the 1204 patients enrolled in JCOG1001, 1200 patients were included. The development of SBO of Grade ≥ IIIa according to the Clavien-Dindo classification was recorded. Univariable and multivariable analyses were performed using the Fine and Gray model to determine the risk factors for SBO.

Results

Fifty-one patients developed SBO (median follow-up duration: 5.6 years). Total gastrectomy, combined resection, and blood loss significantly increased the risk for SBO development in the univariable analysis. Large amount of blood loss was independently associated with SBO development in the multivariable analysis (hazard ratio [HR], 3.089; 95% confidence interval [CI], 1.562-6.109, p = 0.0012). Antiadhesion membrane did not reduce the risk for SBO (HR, 1.299; 95% CI 0.683-2.470; p = 0.4246). In the patients belonging to subgroup analyses who received distal and total gastrectomy, the antiadhesion membrane was not associated with the incidence of SBO.

Conclusions

Antiadhesion membrane did not decrease SBO occurrence rate after open gastrectomy. Therefore, the use of antiadhesion membrane would not be effective for preventing SBO in gastric cancer surgery.

A nonrandomized controlled trial: long-term outcomes of LATG/LAPG for cStage I gastric cancer: Japan Clinical Oncology Group Study JCOG1401

BACKGROUND

A previous report confirmed the safety of laparoscopy-assisted total and proximal gastrectomies (LATG and LAPG) (JCOG1401). This report demonstrates the 5-year relapse-free survival (RFS) and overall survival (OS) after long-term follow-up to confirm the efficacy of these surgical methods as key secondary endpoints for cStage I gastric cancer.

METHODS

This study enrolled patients who had histologically proven gastric adenocarcinoma and were diagnosed with clinical T1N0, T1N(+), or T2N0 tumors according to the 14th edition of the Japanese Classification of Gastric Carcinoma (3rd English edition).

RESULTS

Between April 2015 and February 2017, 246 patients were enrolled, although one patient was excluded because of misregistration. Meticulous follow-up was continued for > 5 years for each patient, and the data were analyzed in March 2022. The 5-year RFS was 90.0% (95% confidence interval [CI] 85.5-93.2%), and the 5-year OS was 91.2% (95% CI 86.9-94.2%) in all enrolled patients. Grade 3 or 4 late postoperative complications were detected in 12.7% of patients.

CONCLUSIONS

This single-arm study showed that the long-term outcomes of LATG/LAPG for cStage I gastric cancer were acceptable, which is considered one of the standard treatments when performed by experienced surgeons. Trail registration UMIN000017155 ( http://www.umin.ac.jp/ctr/ ).

Total neoadjuvant therapy followed by a watch-and-wait strategy for patients with rectal cancer (TOWARd): protocol for single-arm phase II/III confirmatory trial (JCOG2010)

BACKGROUND

Radical surgery is the standard treatment for rectal cancer, but can impact quality of life. Recently, the concept of total neoadjuvant therapy with a watch-and-wait strategy has been proposed in which patients with a cCR after total neoadjuvant therapy do not proceed to surgery. However, most investigations of a watch-and-wait strategy have reported cases where cCR was achieved coincidentally via total neoadjuvant therapy. The aim is to assess whether total neoadjuvant therapy is effective in early-stage rectal cancer in patients that achieve cCR and are offered a watch-and-wait strategy.

METHODS

JCOG2010 (TOWARd) is a multi-institutional, single-arm phase II/III confirmatory investigation of the safety and efficacy of total neoadjuvant therapy followed by a watch-and-wait strategy for rectal cancer. Key eligibility criteria include cT2-3 N0 M0 rectal adenocarcinoma, tumour diameter less than or equal to 5 cm, age 18-75 years, performance status 0-1, and no history of pelvic irradiation or rectal surgery. Total neoadjuvant therapy involves neoadjuvant chemoradiotherapy (capecitabine and radiotherapy: 45 Gy/25 fractions to the whole pelvis plus boost of 5.4 Gy/3 fractions to the primary tumour) followed by consolidation chemotherapy (four cycles of capecitabine/oxaliplatin). Patients will be re-staged every 8 weeks after total neoadjuvant therapy, and those who achieve cCR will undergo a watch-and-wait strategy, those with near complete response will undergo a watch-and-wait strategy or local resection, and those with an incomplete response will undergo radical surgery. The primary endpoint is the cCR rate in phase II and 5-year overall survival in phase III. Secondary endpoints include postoperative anal, urinary, and sexual function. A total of 105 patients (phase II, 40 patients; phase III, 65 patients) will be enrolled over 3.5 years.

CONCLUSION

This trial will determine whether total neoadjuvant therapy and a watch-and-wait strategy is an effective alternative to radical surgery for early-stage rectal cancer in patients with cT2-3 N0 M0 and tumour size less than or equal to 5 cm.

REGISTRATION NUMBER

jRCTs031220288 (https://jrct.niph.go.jp/en-latest-detail/jRCTs031220288).

Randomized controlled phase III trial to investigate superiority of robot-assisted gastrectomy over laparoscopic gastrectomy for clinical stage T1-4aN0-3 gastric cancer patients (JCOG1907, MONA LISA study): a study protocol

BACKGROUND

Laparoscopic gastrectomy (LG) is considered a standard treatment for clinical stage I gastric cancer. Nevertheless, LG has some drawbacks, such as motion restriction and difficulties in spatial perception. Robot-assisted gastrectomy (RG) overcomes these drawbacks by using articulated forceps, tremor-filtering capability, and high-resolution three-dimensional imaging, and it is expected to enable more precise and safer procedures than LG for gastric cancer. However, robust evidence based on a large-scale randomized study is lacking.

METHODS

We are performing a randomized controlled phase III study to investigate the superiority of RG over LG for clinical T1-2N0-2 gastric cancer in terms of safety. In total, 1,040 patients are planned to be enrolled from 46 Japanese institutions over 5 years. The primary endpoint is the incidence of postoperative intra-abdominal infectious complications, including anastomotic leakage, pancreatic fistula, and intra-abdominal abscess of Clavien-Dindo (CD) grade ≥ II. The secondary endpoints are the incidence of all CD grade ≥ II and ≥ IIIA postoperative complications, the incidence of CD grade ≥ IIIA postoperative intra-abdominal infectious complications, relapse-free survival, overall survival, the proportion of RG completion, the proportion of LG completion, the proportion of conversion to open surgery, the proportion of operation-related death, and short-term surgical outcomes. The Japan Clinical Oncology Group Protocol Review Committee approved this study protocol in January 2020. Approval from the institutional review board was obtained before starting patient enrollment in each institution. Patient enrollment began in March 2020. We revised the protocol to expand the eligibility criteria to T1-4aN0-3 in July 2022 based on the results of randomized trials of LG demonstrating non-inferiority of LG to open surgery for survival outcomes in advanced gastric cancer.

DISCUSSION

This is the first multicenter randomized controlled trial to confirm the superiority of RG over LG in terms of safety. This study will demonstrate whether RG is superior for gastric cancer.

TRIAL REGISTRATION

The protocol of JCOG1907 was registered in the UMIN Clinical Trials Registry as UMIN000039825 ( http://www.umin.ac.jp/ctr/index.htm ). Date of Registration: March 16, 2020. Date of First Participant Enrollment: April 1, 2020.

Randomized phase II study comparing neoadjuvant 5-fluorouracil/oxaliplatin/docetaxel versus docetaxel/oxaliplatin/S-1 for patients with type 4 or large type 3 gastric cancer

Macroscopic type 4 and large type 3 gastric cancer, mostly overlapping with scirrhous or linitis plastica type, exhibit a highly invasive nature and show unfavorable prognosis after curative surgery, even with adjuvant chemotherapy. A randomized phase III trial (JCOG0501) failed to demonstrate a survival advantage of neoadjuvant chemotherapy with S-1 plus cisplatin for this population. The current authors initiated a randomized phase II study comparing neoadjuvant chemotherapy with 5-fluorouracil/oxaliplatin/docetaxel versus docetaxel/oxaliplatin/S-1 for type 4 and large type 3 gastric cancer. 76 patients are planned to be enrolled over two years. The primary end point is the proportion of patients with a pathological response (grade 1b or higher) and secondary end points include overall survival and adverse events. Clinical Trial Registration: jRCTs031230231 (rctportal.niph.go.jp).

A randomized phase II study comparing preoperative mFOLFOX6 versus FOLFOXIRI for locally advanced colon cancer: JCOG2006

The prognosis of locally advanced colon cancer (LACC) with surgical resection followed only by adjuvant chemotherapy is poor. Preoperative chemotherapy for LACC patients with risk factors such as cT4bN+ or cT3-4aN2-3 has attracted attention. Here, the authors describe the rationale and design of JCOG2006, a randomized phase II study comparing preoperative chemotherapy with mFOLFOX6 versus FOLFOXIRI for LACC. Their efficacy and safety are evaluated and a determination of which is the more promising treatment will be conducted in a subsequent phase III trial. A total of 86 patients will be accrued from 44 institutions over 2 years. The primary end point is the proportion of patients with a Tumor Regression Score of 0-2, and secondary end points include overall survival, response rate and adverse events. Clinical Trial Registration: jRCTs031210365 (https://jrct.niph.go.jp/).

Racial differences in longitudinal toxicities of anticancer agents in early phase cancer clinical trials

BACKGROUND

Racial differences have been reported in toxicity outcomes for anticancer drug treatments. However, these observations were often from studies with small sample sizes, and many only reported the maximum grade of toxicity and no longitudinal information. This current analysis aims to investigate racial differences in longitudinal toxicities using a large-scale clinical trials database.

METHODS

Early-phase clinical trials sponsored by the Cancer Therapy Evaluation Program at the National Cancer Institute, USA, that evaluated cytotoxic drugs and molecularly targeted agents between March 2000 and December 2012 were studied. Race was categorized as White, Black or African-American, and Asian. Each toxicity's grade prevalence, mean grade at each cycle, and time to develop grade 2 or higher toxicity was evaluated.

RESULTS

In total, 25,442 patients from 697 trials were included in this study. The number of patients categorized as White, Black, and Asian designations was 22,756 (89%), 1874 (7%), and 812 (3%), respectively. Notable findings include the rate of any grade of diarrhea in Black people was 26% and 21% lower than that of White and Asian people. The median time to the first grade 2 or higher event was 6 cycles in White people, 8 in Black people, and 6 in Asian people. The rate of any grade hyperglycemia was significantly higher in Asian people.

CONCLUSIONS

Although we identified several racial differences in longitudinal toxicities, most were of generally lower grade. Further study is needed to clarify the cause of racial differences in treatment-associated toxicities.

Role of reduction gastrectomy in patients with gastric cancer with a single non-curable factor: Supplementary analysis of REGATTA trial

Background

REGATTA trial failed to demonstrate the survival benefit of reduction gastrectomy in patients with advanced gastric cancer with a single non-curable factor. However, a significant interaction was found between the treatment effect and tumor location in the subset analysis. Additionally, the treatment effect appeared to be different between Japan and Korea. This supplementary analysis aimed to elucidate the effect of reduction surgery based on tumor location and country.

Methods

Multivariable Cox regression analyses in each subgroup were performed to estimate the hazard ratio (HRadj), including the following variables as explanatory variables: country, age, sex, incurable factor, cT, cN, primary tumor, performance status, histological type, and macroscopic type.

Results

Patients (95 in Japan and 80 in Korea) were randomized to chemotherapy alone (86 patients) or gastrectomy plus chemotherapy (89 patients). The subgroup analysis according to the country revealed a worse overall survival in gastrectomy plus chemotherapy arm in Japan (hazard ratio: 1.32, 95% confidence interval: 0.85-2.05), but not in Korea (hazard ratio: 0.85.95% confidence interval: 0.52-1.40). Overall survival was better in distal gastrectomy plus chemotherapy compared with chemotherapy alone (hazard ratio = 0.69, 95% confidence interval: 0.42-1.13), and worse in total gastrectomy plus chemotherapy compared with chemotherapy alone (hazard ratio = 1.34, 95% CI: 0.93-1.94), which was more remarkable in Korea than in Japan.

Conclusions

Primary chemotherapy is a standard of care for advanced gastric cancer; however, the survival benefits from reduction by distal gastrectomy remained controversial.

Utility of circulating tumour DNA for prognosis and prediction of therapeutic effect in locally recurrent rectal cancer: study protocol for a multi-institutional, prospective observational study (JCOG1801A1, CAP-LR study)

INTRODUCTION

In locally recurrent rectal cancer (LRRC), surgery is a standard treatment for resectable disease. However, short-term and long-term outcomes are unsatisfactory due to the invasive nature of surgical procedures and the high proportion of local recurrence. Consequently, the identification of reliable prognostic and predictive biomarkers to guide treatment decisions may improve outcomes. The presence of circulating tumour DNA (ctDNA) in plasma after surgery may signify the presence of minimal residual disease (MRD) in various cancers. Therefore, we have launched a multi-institutional prospective observational study of ctDNA for MRD detection in conjunction with JCOG1801, a randomised, controlled phase III trial evaluating the efficacy of preoperative chemoradiotherapy (pre-CRT) compared with up-front surgery for LRRC (jRCTs031190076, NCT04288999).

METHODS AND ANALYSIS

JCOG1801A1 is the first correlative study that assesses ctDNA in LRRC patients enrolled in JCOG1801. Patients randomised to up-front surgery will provide whole blood samples at three time points (prior to surgery, after surgery and after postoperative chemotherapy); those to pre-CRT will provide at five time points (prior to pre-CRT, after pre-CRT, prior to surgery, after surgery and after postoperative chemotherapy). Cell-free DNA will be extracted from plasma and analysed by Guardant Reveal, a tumour tissue-agnostic assay that assesses both genomic alterations and methylation patterns to determine the presence or absence of ctDNA. We will compare the prognosis and treatment response of patients according to their ctDNA status after surgery and at other time points.

ETHICS AND DISSEMINATION

The study protocol received approval from the Institutional Review Board of National Cancer Center Hospital East on behalf of the participating institutions in February 2023. The study is conducted in accordance with the precepts established in the Declaration of Helsinki and Ethical Guidelines for Medical and Biological Research Involving Human Subjects. Written informed consent will be obtained from all eligible patients prior to registration.

Identifying Risk Factors of Complications following Total Gastrectomy for Gastric Cancer: Comparison between Splenectomy and Spleen-Preserving Surgery - A Supplementary Analysis of JCOG0110

INTRODUCTION

Splenectomy for proximal gastric cancer was found to offer no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). Although many studies have explored risk factors for morbidities following total gastrectomy, none have assessed the risk factors for postoperative complications in spleen-preserving total gastrectomy.

METHODS

Using data from 505 patients enrolled in a previous randomized trial, risk factors for postoperative complications were identified by multivariable logistic regression analysis. Then, the risk factors were assessed separately between splenectomy and spleen-preserving total gastrectomy.

RESULTS

Postoperative complications were identified in 119 patients (23.6%) and were more common following splenectomy than following spleen-preserving surgery (30.7% and 16.1%, respectively, p < 0.01). Multivariable analysis revealed that age ≥65 years (p = 0.032), body mass index ≥25 (p = 0.003), and blood loss ≥350 (p = 0.019) were independent risk factors for postoperative complications in the entire cohort. Among them, only body mass index was a significant independent risk factor for complications in both spleen preservation (p = 0.047) and splenectomy groups (p = 0.017).

CONCLUSION

Risk factors for postoperative complications were essentially the same between splenectomy and spleen preservation. Being overweight increased the risk of postoperative complications.

Phase II biomarker identification study of anti-VEGF agents with FOLFIRI for pretreated metastatic colorectal cancer

Chemotherapy plus antiangiogenic agents, including bevacizumab, ramucirumab and aflibercept, is a standard second-line treatment for patients with metastatic colorectal cancer, but which specific agents should be selected is ambiguous due to a lack of clear evidence from prospective studies. Previous reports have suggested ramucirumab and aflibercept could be more effective than bevacizumab in patients with high VEGF-D and high VEGF-A, respectively. JCOG2004 is a three-arm, randomized, phase II study to identify predictive biomarkers for these agents in patients who have failed first-line treatment. The study will enroll 345 patients from 52 institutions for 2 years, with progression-free survival in high VEGF-D (bevacizumab vs ramucirumab) and high VEGF-A (bevacizumab vs aflibercept) serving as the primary end point. Clinical Trial Registration: jRCTs031220058 (www.jrct.niph.go.jp).

Definitive S-1/mitomycin-C chemoradiotherapy for stage II/III anal canal squamous cell carcinoma: a phase I/II dose-finding and single-arm confirmatory study (JCOG0903)

BACKGROUND

Definitive chemoradiotherapy (CRT) with 5-fluorouracil plus mitomycin-C is a standard treatment for stage II/III squamous cell carcinoma of the anal canal (SCCA). We performed this dose-finding and single-arm confirmatory trial of CRT with S-1 plus mitomycin-C to determine the recommended dose (RD) of S-1 and evaluate its efficacy and safety for locally advanced SCCA.

METHODS

Patients with clinical stage II/III SCCA (UICC 6th) received CRT comprising mitomycin-C (10 mg/m² on days 1 and 29) and S-1 (60 mg/m²/day at level 0 and 80 mg/m²/day at level 1 on days 1-14 and 29-42) with concurrent radiotherapy (59.4 Gy). Dose-finding used a 3 + 3 cohort design. The primary endpoint of the confirmatory trial was 3-year event-free survival. The sample size was 65, with one-sided alpha of 5%, power of 80%, and expected and threshold values of 75% and 60%, respectively.

RESULTS

Sixty-nine patients (dose-finding, n = 10; confirmatory, n = 59) were enrolled. The RD of S-1 was determined as 80 mg/m²/day. Three-year event-free survival in 63 eligible patients who received the RD was 65.0% (90% confidence interval 54.1-73.9). Three-year overall, progression-free, and colostomy-free survival rates were 87.3%, 85.7%, and 76.2%, respectively; the complete response rate was 81% on central review. Common grade 3/4 acute toxicities were leukopenia (63.1%), neutropenia (40.0%), diarrhea (20.0%), radiation dermatitis (15.4%), and febrile neutropenia (3.1%). No treatment-related deaths occurred.

CONCLUSIONS

Although the primary endpoint was not met, S-1/mitomycin-C chemoradiotherapy had an acceptable toxicity profile and favorable 3-year survival and could be a treatment option for locally advanced SCCA.

CLINICAL TRIAL INFORMATION

jRCTs031180002.

Early tumor shrinkage and depth of response in patients with metastatic esophageal cancer treated with 2-weekly docetaxel combined with cisplatin plus fluorouracil: an exploratory analysis of the JCOG0807

BACKGROUND

We herein investigated the association between early tumor shrinkage (ETS) and depth of response (DpR) and clinical outcomes in patients with metastatic esophageal cancer treated with 2-weekly docetaxel combined with cisplatin plus fluorouracil (bDCF) using data from the JCOG0807, a phase I/II trial of bDCF as first-line chemotherapy for metastatic esophageal cancer.

METHODS

ETS was defined as a percent decrease in the sum of the target lesions' longest diameter after 8 weeks, whereas DpR was defined as a percentage of the maximal tumor shrinkage during the treatment course. Multivariable analyses were conducted to identify significant prognostic variables in progression-free survival (PFS) and overall survival (OS): one for ETS and covariates, and another for DpR and covariates.

RESULTS

Among 53 patients, 35 patients with ETS ≥ 20% (66.0%) had longer PFS (7.5 vs. 3.4 months, hazard ratio [HR]: 0.26, 95% confidence interval [95% CI] 0.14-0.49), OS (13.8 vs. 6.1 months, HR 0.20, 95% CI 0.11-0.39), and PPS (6.4 vs. 2.8 months, HR 0.38, 95% CI 0.20-0.72) than those with ETS < 20%. In addition, 37 patients with DpR ≥ 30% (69.8%) had longer PFS (7.5 vs. 2.9 months, HR 0.17, 95% CI 0.08-0.34), OS (13.8 vs. 6.0 months, HR 0.14, 95% CI 0.07-0.27), and PPS (6.8 vs. 2.8 months, HR 0.30, 95% CI 0.15-0.58) than those with DpR < 30%. Multivariable analyses revealed that each ETS and DpR was an independent factor of longer PFS and OS.

CONCLUSIONS

ETS and DpR might be associated with clinical outcomes in patients with metastatic esophageal cancer treated with bDCF.

Patient-reported outcome and quality of life research policy: Japan Clinical Oncology Group (JCOG) policy

Assessments of patient-reported outcomes and health-related quality of life in cancer clinical trials have been increasingly emphasized recently because patient and public involvement in cancer treatment development has been promoted by regulatory authorities and academic societies. To assess patient experiences during and after cancer treatment, there is interest in implementing patient-reported outcome and health-related quality of life assessments into cancer clinical trials. The Japan Clinical Oncology Group quality of life ad hoc committee previously created a version of the Quality of Life Assessment Policy in 2006. Recently, there has been increasing demand from Japan Clinical Oncology Group researchers to assess patient-reported outcome/health-related quality of life in clinical trials. Although guidelines are available regarding planning and reporting clinical trials that include patient-reported outcome/health-related quality of life as an endpoint, there are still issues regarding the lack of consensus on standardized methods for analysing and interpreting the results. Hence, it was considered necessary to reorganize the Japan Clinical Oncology Group patient-reported outcome/quality of life research committee and to revise the former patient-reported outcome/quality of life research policy to promote patient-reported outcome/health-related quality of life research in future Japan Clinical Oncology Group trials. The purpose of this Japan Clinical Oncology Group patient-reported outcome/quality of life research policy is to define patient-reported outcome/health-related quality of life research and provide guidelines for including patient-reported outcome/health-related quality of life as an endpoint in Japan Clinical Oncology Group trials.

A randomised phase II study of modified FOLFIRINOX versus gemcitabine plus nab-paclitaxel for locally advanced pancreatic cancer (JCOG1407)

AIM

We compared the efficacy of modified 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin (mFOLFIRINOX) with that of gemcitabine plus nab-paclitaxel (GnP) for locally advanced pancreatic cancer (LAPC).

METHODS

Patients with untreated LAPC were randomly assigned (1:1) to receive mFOLFIRINOX or GnP. One-year overall survival (OS) was the primary endpoint. The major secondary end-points included progression-free survival (PFS), response rate (RR), carbohydrate antigen 19-9 (CA19-9) response, and adverse events. The sample size was 124 patients to select a more effective regimen with a minimum probability of 0.85 and to examine the null hypothesis of the 1-year OS <53%.

RESULTS

Of the 126 patients enrolled from 29 institutions, 125 were deemed eligible. The 1-year OS was 77.4% (95% CI, 64.9-86.0) and 82.5% (95% CI, 70.7-89.9) in the mFOLFIRINOX and GnP arms, respectively. The median PFS was 11.2 (95% CI, 9.9-15.9) and 9.4 months (95% CI, 7.4-12.8) in the mFOLFIRINOX and GnP arms, respectively. The RR and CA19-9 response rate were 30.9% (95% CI, 19.1-44.8) and 57.1% (95% CI, 41.0-72.3) and 42.1% (95% CI 29.1-55.9) and 85.0% (95% CI, 70.2-94.3) in the mFOLFIRINOX and GnP arms, respectively. Grade 3-4 diarrhoea and anorexia were predominant in the mFOLFIRINOX arm.

CONCLUSION

GnP was considered the candidate for a subsequent phase III trial because of its better RR, CA19-9 response, and mild gastrointestinal toxicities. Both regimens displayed higher efficacy in the 1-year survival than in the historical data of gemcitabine monotherapy.

Impact of correlations between prioritized outcomes on the net benefit and its estimate by generalized pairwise comparisons

Benefit-risk balance is gaining interest in clinical trials. For the comprehensive assessment of benefits and risks, generalized pairwise comparisons are increasingly used to estimate the net benefit based on multiple prioritized outcomes. Although previous research has demonstrated that the correlations between the outcomes impact the net benefit and its estimate, the direction and magnitude of this impact remain unclear. In this study, we investigated the impact of correlations between two binary or Gaussian variables on the true net benefit values via theoretical and numerical analyses. We also explored the impact of correlations between survival and categorical variables on the net benefit estimates based on four existing methods (Gehan, Péron, Gehan with correction, and Péron with correction) in the presence of right censoring via simulation and application to actual oncology clinical trial data. Our theoretical and numerical analyses revealed that the true net benefit values were impacted by the correlations in various directions depending on the outcome distributions. With binary endpoints, this direction was governed by a simple rule with a threshold of 50% for a favorable outcome. Our simulation showed that the net benefit estimates based on Gehan's or Péron's scoring rule could be substantially biased in the presence of right censoring, and that the direction and magnitude of this bias were associated with the outcome correlations. The recently proposed correction method greatly reduced this bias, even in the presence of strong outcome correlations. The impact of correlations should be carefully considered when interpreting the net benefit and its estimate.

Five-year follow-up results of a randomized phase III trial comparing 4 and 8 courses of S-1 adjuvant chemotherapy for pathological stage II gastric cancer: JCOG1104 (OPAS-1)

381

Background: Postoperative S-1 (80 mg/m2/day for 4 weeks and 2 weeks rest in one course) for 1 year corresponding to 8 courses is a standard adjuvant chemotherapy for pathological stage (pStage) II gastric cancer. To shorten the duration of S-1 chemotherapy, we conducted a phase III trial to confirm non-inferiority in relapse-free survival (RFS) of 4 courses of S-1 to 8 courses of S-1 for pStage II gastric cancer. When 590 patients were enrolled, the study was closed at the first interim analysis because of futility. The RFS at 3 years was 89.8% for 4-courses and 93.1% for 8-courses (HR 1.84, 95% confidence interval (CI) 0.93-3.63). This is a final 5-year follow-up results of this study. Methods: Key eligibility criteria were pStage II except for T1 and T3N0 (7th edition of TNM), ECOG performance status 0-1, R0 resection with D2 lymph node dissection for >clinical stage (cStage) II or D1+ lymph node dissection for cStage I, within 7 weeks after surgery, and age between 20 and 80 years. The total sample size was determined to be 1,000 with a 3-year RFS of 85% in both arms and non-inferiority margin of hazard ratio (HR) of 1.37, with one-sided alpha of 5% and 80% power. Results: Between Feb 2012 and Mar 2017, 590 patients, 295 for each arm, were enrolled. When closing the study, the patients who were allocated to the 4-courses arm were informed of the primary results and the recommendation to continue S-1 until 8 courses as an off-protocol when they were receiving S-1. The cut-off date for the final follow-up data was March 22, 2022 with a median follow-up period for surviving patients of 6.0 years (IQR; 5.0-7.2). In 4-courses arm, 27 patients were receiving S-1 when the study was closed at the interim analysis. Among them, 22 patients expressed their will to continue until 8 courses. The RFS at 3/5 years was 90.1%/85.6% for 4-courses and 92.2%/87.7% for 8-courses (HR 1.27, 95% CI 0.85-1.89). The overall survival at 3/5 years was 93.2%/88.6 for 4-courses and 94.9%/89.7 for the 8-courses (HR 1.12, 95% CI 0.72-1.75). The HR of the cumulative incidence of the recurrence was 1.38 (95% CI 0.85-2.24) for the 4-courses against 8-courses. Recurrence was frequently observed in patients who received up to 4 courses of S-1 (38 for 4-courses vs. 28 for 8 courses). The HR of the cumulative incidence of the peritoneal recurrence was 1.54 (95% CI 0.82-2.89) for the 4-courses against 8-courses. Conclusions: This final follow-up data confirmed the primary results presented at the interim analysis. S-1 adjuvant chemotherapy for 1 year for pStage II gastric cancer is highly recommended. Clinical trial information: 000007306 .

Survival results by the prospectively determined clinical staging for locally advanced gastric cancer: An ancillary study of JCOG1302A (JCOG1302A2)

392

Background: Recently, neoadjuvant chemotherapy has been recognized as a promising strategy to improve the survival of patients with advanced gastric cancer. On the other hand, given the adverse events and treatment cost of chemotherapy, the candidate for NAC should be limited to patients who can benefit from NAC. In fact, as previously reported, the proportion of pathological stage I tumors was 50.4% in cT2N0, 38.7% in cT2N(+), 26.7% in cT3N0, 10.6% in cT3N(+), 9.0% in cT4aN0, and 3.0% in cT4aN(+). Therefore, clinical staging before initiation of treatment is increasingly important for determining therapeutic strategy. However, the long-term survival stratified by the prospectively-determined clinical stage has not been fully investigated. Methods: Between July 2013 and November 2014, the JCOG1302A examined 1260 patients with a clinical diagnosis of cT2/T3/T4, cN0/N1/N2/N3, M0, except for diffuse large tumors like linitis plastica and extensive bulky nodal diseases according to the Japanese Classification of Gastric Carcinoma (3rd English edition). The cT diagnosis was made by upper gastrointestinal endoscopy and comprehensive findings on upper abdominal contrast CT scan with 1 or 5 mm slice thickness. Lymph nodes with a shortest dimension greater than 8 mm or a longest dimension greater than 10 mm were defined as positive for metastasis. In this follow-up study, the survival data by stratifying the clinical staging were evaluated. Results: Among 1260 patients, survival data of 1177 were analyzed. With a median follow-up for 821 surviving patients of 6.0 years, the 5y-OS was 82.1% (95% CI, 77.3-85.9) in cT2 (n=319), 72.7% (68.2-76.6) in cT3 (n=450), 60.0% (54.9-64.7) in cT4a (n=401), and 40.0% (5.2-75.3) in cT4b (n=6), while that was 78.0% (74.2-81.2) in cN0 (n=560), 70.6% (65.4-75.2) in cN1 (n=350), 59.1% (52.5-65.1) in cN2 (n=241), and 28.4% (12.7-46.5) in cN3 (n=26), respectively. When combined with cT and cN, 5y-OS was 83.5% (77.8-87.8) in cT2N0 (n=226), 77.2% (71.0-82.2) in cT3N0 (n=232), 66.8% (56.3-75.2) in cT4aN0 (n=100), 100% in cT4bN0 (n=1), 78.7% (68.6-85.8) in cT2N(+)(n=93), 68.0% (61.1-73.8) in cT3N(+)(n=218), 57.7% (51.7-63.2) in cT4aN(+)(n=301), and 25.0% (0.9-66.5) in cT4bN(+)(n=5). Conclusions: Both the survival and the proportion of overdiagnosis of stage I patients in patients with cT4aN0, categorized as cstage IIB, was almost same as in those cT3N(+) categorized as cstage III. In considering the candidate for further treatment development of NAC with high toxic regime in future, cT3N(+) and cT4aN0 should be considered as equivalent category.

Comparison of clinical features by primary sites in patients with biliary tract cancer who received gemcitabine-based chemotherapy: An exploratory analysis of JCOG1113

548

Background: Biliary tract cancers (BTCs) include gallbladder cancer (GBC), intrahepatic cholangiocarcinoma (IHCC), extrahepatic cholangiocarcinoma (EHCC), and ampulla of Vater cancer (AV). Although it was previously reported that there were differences in clinical features individually, the reported data were limited to data from some subgroup analyses of recent randomized controlled trials. JCOG1113 (UMIN000010667) showed the non-inferiority of gemcitabine plus S-1 to gemcitabine plus cisplatin in terms of overall survival (OS) in patients (pts) with advanced BTCs. We aimed to compare clinical features among the primary sites of BTCs using JCOG1113 data. Methods: Among the 354 pts enrolled in JCOG1113, 352 pts were included in this analysis except for 2 pts without BTCs. We compared the patient characteristics and treatment outcomes, such as OS, progression-free survival (PFS), and objective response rate (ORR), among the four primary sites. Results: Of the 352 pts, 137 pts (38.9%), 94 pts (26.7%), 108 pts (30.7%) and 13 pts (3.7%) had GBC, IHCC, EHCC, and AV, respectively. GBC was more common in females (58.4%) than males, in contrast to the other primary sites. The percentage of pts with metastatic disease for GBC was the highest (78.1%) and involved multiple metastatic organs (41.6%), in contrast with the other primary sites. The median OS for GBC, IHCC, EHCC and AV were 12.6 months (reference), 15.7 months (hazard ratio [HR]; 0.749, 95% confidence interval [CI], 0.559-1.005), 16.3 months (0.704, 0.532-0.934) and 11.5 months (1.148, 0.633-2.080), respectively. The median PFS for GBC, IHCC, EHCC and AV were 5.7 months (reference), 6.2 months (0.843, 0.644-1.104), 8.7 months (0.636, 0.489-0.826) and 4.1 months (1.506, 0.851-2.665), respectively. The ORRs for GBC, IHCC, EHCC and AV were 34.4%, 28.9%, 34.4%, and 0.0%, respectively. Conclusions: Except for AV which included a few patients in this trial, GBC showed a poorer prognosis compared with the other primary sites. Furthermore, it was more likely to include metastatic disease and multiple metastases, and this is likely one of the causes of the poorer prognosis. [Table: see text]

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

354

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 .

Single-arm confirmatory trial of total neoadjuvant therapy and watch-and-wait strategy for patients with low rectal cancer: Japan Clinical Oncology Group study (JCOG2010, TOWARd study)

TPS269

Background: Radical surgery is the standard treatment for advanced lower rectal cancer, but postoperative complications and sequelae are major problems. Recently, some patients treated with preoperative chemoradiotherapy (CRT) have been reported to achieve a clinical complete response (cCR) and be cured with a subsequent watch-and-wait strategy (W&W) without surgery. Moreover, the introduction of total neoadjuvant therapy (TNT) consisting of CRT and systemic chemotherapy has increased proportion of cCR. However, most previous studies on W&W have reported cases in which cCR was achieved incidentally as a result of preoperative CRT or TNT for advanced lower rectal cancer. It is unclear whether combining TNT that is highly effective in early stage rectal cancer and subsequent W&W without surgery is an effective intention-to-cure treatment for advanced lower rectal cancer when cCR is obtained after TNT. The purpose of this single-arm confirmatory trial is to evaluate the efficacy and safety of TNT and intended W&W for cT2-T3 advanced lower rectal cancer with a tumor diameter of 5 cm or less. Methods: Key eligibility criteria include low rectal adenocarcinoma with tumor diameter 5 cm or less, cT2 or cT3 tumor depth, no lymph node metastasis, no distant metastasis, no history of pelvic irradiation or rectal surgery, age 18-75 years, and sufficient organ function. Eligible patients are receiving TNT. CRT consists of the standard dose of capecitabine (1650 mg/m2/day) and radiotherapy (45 Gy/25 fractions to whole pelvis plus boost of 5.4 Gy/3 fractions to primary tumor). Consolidation chemotherapy consists of 4 courses of CAPOX (oxaliplatin 130 mg/m2 on day1 and capecitabine 2000 mg/m2/day on day1-14). After completing TNT, patients will be re-staged according to Memorial Sloan Kettering Cancer Center Criteria. Patients with cCR at the primary site will move to W&W, patients with a near complete response will move to either W&W or undergo local resection, and patients with an incomplete response will undergo total mesorectal excision. All patients will be followed every 3 months for 2 years after re-staging, and every 6 months for 3 years after that. The primary endpoint in phase II is the proportion of cCR at re-staging by central review and in phase III is 5-year overall survival (OS). In the phase II part, 40 patients were required with a one-sided alpha of 5%, power of 80%, a threshold value of 20%, and an expected value of 40%. Based on the results of previous studies, we set the threshold 5-year OS at 87% in the phase III part. The sample size was calculated as 105 including the phase II part with a one-sided alpha of 5%, power of 80%, and the expected 5-year OS of 95%. The first patient was enrolled in September 2022. Clinical trial information: jRCTs031220288 .

The new prognostic index of advanced gastric cancer using the data from JCOG1013

342

Background: We previously reported that performance status (PS) ≥1, no prior gastrectomy, number of metastatic sites ≥2, and high serum ALP level are poor prognosis factors and proposed a JCOG prognostic index by analyzing the data of advanced gastric cancer (AGC) patients enrolled in JCOG9912 (Takahari D et al. Oncologist 2014). Recently, Neutrocyte/ Lymphocyte Ratio (NLR) and diffuse type of cancer have also been reported to be prognostic factors of AGC. Methods: Prognostic factors were assessed in patients with AGC who enrolled in JCOG1013, the phase III study comparing docetaxel, cisplatin, and S-1 (DCS) versus cisplatin and S-1 (CS) in first-line treatment (Yamada Y et al. Lancet Gastroenterol Hepatol. 2019) was retrospectively evaluated using a Cox proportional regression model. The overall adequacy of risk prediction in the modified JCOG prognostic index and the original index were assessed by C-statistics. Results: Among 741 patients, 730 with all data for this analysis were selected. The median overall survival (OS) was 14.9 months (95% confidence interval [CI], 14.1–15.8). The median OS of the good (n=233), moderate (n=444), and poor (n=53) risk groups by the original JCOG index was 19.0, 14.2, and 9.1 months, respectively. The HRs compared with the good group were 1.59 [95% CI, 1.33–1.89; p < 0.0001] in the moderate group, and 2.47 [95% CI, 1.81–3.38; p < 0.0001] in the poor group with C-statistics of 0.572. In the multivariable analysis of 7 factors which showed p<0.1 in univariable analysis, PS ≥1 (hazard ratio [HR], 1.490; 95% CI, 1.264–1.755; p < 0.0001), diffuse type (HR, 1.337; 95% CI, 1.122–1.594; p = 0.012), number of metastatic sites ≥2 (HR, 1.256; 95% CI, 1.058–1.492; p = 0.0093), and NLR≥3.1 (HR, 1.539; 95% CI, 1.309–1.809; p < 0.0001) were significantly associated with worse prognosis, whereas no prior gastrectomy, peritoneal metastasis, and high serum ALP level were not. As the modified JCOG prognostic index, patients were classified into three groups according to the number of these four newly identified prognostic risk factors: good (no), moderate (1 or 2), and poor (3 or 4). Median OS of the good (n=221), moderate (n=441), and poor (n=68) risk groups was 20.6, 13.7, and 9.4 months, respectively. The HRs compared with the good group were 1.70 [95% CI, 1.42–2.03; p < 0.0001] in the moderate group, and 3.11 [95% CI, 2.33–4.14; p < 0.0001] in the poor group with C-statistics of 0.591. Three groups by the modified JCOG prognostic index also showed clear separation of OS in either subgroup of DCS or CS. Conclusions: Modified JCOG prognostic index, including NLR ≥3.1 and diffuse type instead of no prior gastrectomy and high serum ALP level, showed clear stratification of OS in JCOG1013.

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 .

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/).

Randomized phase III study of high-dose methotrexate and whole-brain radiotherapy with/without temozolomide for newly diagnosed primary CNS lymphoma: JCOG1114C

BACKGROUND

The goal was to determine whether the addition of temozolomide (TMZ) to the standard treatment of high-dose methotrexate (HD-MTX) and whole-brain radiotherapy (WBRT) for primary central nervous system lymphoma (PCNSL) improves survival.

METHODS

An open-label, randomized, phase III trial was conducted in Japan, enrolling immunocompetent patients aged 20-70 years with histologically confirmed, newly diagnosed PCNSL. After administration of HD-MTX, patients were randomly assigned to receive WBRT (30 Gy) ± 10 Gy boost (arm A) or WBRT ± boost with concomitant and maintenance TMZ for two years (arm B). The primary endpoint was overall survival (OS).

RESULTS

Between September 29, 2014 and October 15, 2018, 134 patients were enrolled, of whom 122 were randomly assigned and analyzed. At the planned interim analysis, two-year OS was 86.8% (95% confidence interval [CI]: 72.5-94.0%) in arm A and 71.4% (56.0-82.2%) in arm B. The hazard ratio was 2.18 (95% CI: 0.95 to 4.98), with the predicted probability of showing the superiority of arm B at the final analysis estimated to be 1.3%. The study was terminated early due to futility. O 6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status was measured in 115 tumors, and it was neither prognostic nor predictive of TMZ response.

CONCLUSIONS

This study failed to demonstrate the benefit of concomitant and maintenance TMZ in newly diagnosed PCNSL.

Clinical factors associated with noncurative endoscopic submucosal dissection for the expanded indication of intestinal-type early gastric cancer: Post hoc analysis of a multi-institutional, single-arm, confirmatory trial (JCOG0607)

OBJECTIVES

The multi-institutional, single-arm, confirmatory trial JCOG0607 showed excellent efficacy of endoscopic submucosal dissection (ESD) for the expanded indication of intramucosal intestinal-type early gastric cancer (EGC), which consists of two groups: lesions >2 cm if clinical finding of ulcer (cUL)-negative, or those ≤3 cm if cUL-positive because of the expected low risk of lymph node metastasis. However, the proportion of noncurative resections (NCR) requiring additional surgery was high (32.4%). This post hoc analysis aimed to explore the clinical factors associated with NCR.

METHODS

As the expanded indication includes two different groups, we explored the clinical factors associated with NCR separately in cUL-negative (>2 cm) and cUL-positive (≤3 cm) groups using the log-linear model.

RESULTS

Two hundred and sixty cUL-negative and 206 cUL-positive EGCs were analyzed. The proportions of NCR were 33.8% in the cUL-negative group and 29.6% in the cUL-positive group. A multivariable analysis demonstrated that moderately differentiated predominant histology diagnosed in pretreatment biopsy (risk ratio [RR] 1.93, 95% confidence interval [CI] 1.34-2.77, P < 0.001) and lesion in the upper stomach (RR 1.75, 95% CI 1.03-2.96, P = 0.038) in the cUL-negative EGCs, and tumor size >2 cm (RR 1.78, 95% CI 1.22-2.58, P = 0.003) and female sex (RR 1.62, 95% CI 1.07-2.44, P = 0.021) in the cUL-positive EGCs were independent factors associated with NCR.

CONCLUSIONS

Clinical risk factors associated with NCR were different between cUL-negative and cUL-positive EGCs. To avoid NCR, we need to take these factors into account when deciding expanded indications for ESD.

Protocol digest of a phase III trial to evaluate the efficacy of preoperative chemotherapy with S-1 plus oxaliplatin followed by D2 gastrectomy with postoperative S-1 in locally advanced gastric cancer: Japan Clinical Oncology Group study JCOG1509 (NAGISA Trial)

In Japan, postoperative chemotherapy is a standard care for stage II/III gastric cancer after curative resection with D2 lymph node dissection, and the clinical outcomes of patients with stage III gastric cancer are unsatisfactory. A combination of oral S-1 and oxaliplatin, that is the standard chemotherapy regimen for unresectable advanced/recurrent gastric cancer associated with a high response rate, was considered the most promising preoperative chemotherapy regimen. This randomized phase III trial was started in September 2016 to confirm the superiority of preoperative chemotherapy with S-1 plus oxaliplatin followed by D2 gastrectomy with postoperative chemotherapy compared with D2 gastrectomy with postoperative chemotherapy for patients with clinical T3–4N1–3 M0 locally advanced gastric cancer in terms of overall survival. A total of 470 patients will be enrolled from 63 hospitals in Japan for 8.5 years. This trial has been registered in the Japan Registry of Clinical Trials as jRCTs031180350 [https://jrct.niph.go.jp/latest-detail/jRCTs031180350].

Protocol of a randomized phase II/III study of gemcitabine plus nab-paclitaxel combination therapy versus modified FOLFIRINOX versus S-IROX for metastatic or recurrent pancreatic cancer: JCOG1611 (GENERATE)

Gemcitabine plus nab-paclitaxel and combination chemotherapy with fluorouracil, leucovorin, irinotecan and oxaliplatin are a standard treatment for metastatic or recurrent pancreatic cancer. Recent studies on metastatic pancreatic cancer have demonstrated promising results of modified fluorouracil, leucovorin, irinotecan and oxaliplatin and S-1, irinotecan and oxaliplatin. A three-arm randomized phase II/III trial has been conducted since April 2019 to confirm the superiority of modified fluorouracil, leucovorin, irinotecan and oxaliplatin and S-1, irinotecan and oxaliplatin over Gemcitabine plus nab-paclitaxel in patients with metastatic or recurrent pancreatic cancer. A total of 732 patients will be enrolled from 42 Japanese institutions within 5 years. The primary endpoint is the response rate in the S-1, irinotecan and oxaliplatin arm for phase II portion and overall survival for phase III portion. The secondary endpoints for phase III portion are progression-free survival, response rate, adverse events, serious adverse events and dose intensity. This trial is registered with the Japan Registry of Clinical Trials [https://jrct.niph.go.jp/], number jRCTs031190009.

A randomized controlled trial comparing perioperative vs. postoperative mFOLFOX6 for lower rectal cancer with suspected lateral pelvic lymph node metastasis (JCOG1310): a phase II/III randomized controlled trial

Objective

The optimal perioperative chemotherapy for lower rectal cancer with lateral pelvic lymph node metastasis remains unclear. We evaluated the efficacy and safety of perioperative mFOLFOX6 in comparison with postoperative mFOLFOX6 for rectal cancer patients undergoing total mesorectal excision with lateral lymph node dissection.

Methods

We conducted an open label randomized phase II/III trial in 18 Japanese institutions. We enrolled patients with histologically proven lower rectal adenocarcinoma with clinical pelvic lateral lymph node metastasis who were randomly assigned (1:1) to receive postoperative mFOLFOX6 (12 courses of intravenous oxaliplatin [85 mg/m²] with L-leucovorin [200 mg/m²] followed by 5-fluorouracil [400 mg/m², bolus and 2400 mg/m², continuous infusion, repeated every 2 weeks]) or perioperative mFOLFOX6 (six courses each preoperatively and postoperatively). The primary endpoint was overall survival (OS). The trial is registered with Japan Registry of Clinical Trials, number jRCTs031180230.

Results

Between May 2015, and May 2019, 48 patients were randomized to the postoperative arm (n = 26) and the perioperative arm (n = 22). The trial was terminated prematurely due to poor accrual. The 3-year OS in the postoperative and perioperative groups were 66.1 and 84.4%, respectively (HR 0.58, 95% CI [0.14–2.45], one-sided P = 0.23). The pathological complete response rate in the perioperative group was 9.1%. Grade 3 postoperative surgical complications were more frequently observed in the perioperative arm (50.0 vs. 12.0%). One treatment-related death due to sepsis from pelvic infection occurred in the postoperative group.

Conclusions

Perioperative mFOLFOX6 may be an insufficient treatment to improve survival of lower rectal cancer with lateral pelvic lymph node metastasis.

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.

Second gastric cancer after curative endoscopic resection of differentiated-type early gastric cancer: post-hoc analysis of a single-arm confirmatory trial

BACKGROUND AND AIMS

Endoscopic resection (ER) for early gastric cancer (EGC) can preserve the stomach; however, the remaining stomach can develop second gastric cancer. Few reports have prospectively investigated the incidence and treatment outcomes of second gastric cancer.

METHODS

This post-hoc analysis used the dataset of the single-arm confirmatory trial, JCOG0607. The key inclusion criteria for JCOG0607 were solitary differentiated-type EGC and no previous gastrectomy or endoscopic treatment for EGC. Three hundred seventeen patients who underwent curative ER were included in this study. Surveillance endoscopy was performed 1 to 3 months after the initial ER and subsequently annually for at least 5 years. A lesion detected ≤1 year and >1 year after the initial ER was defined as overlooked gastric cancer (OGC) and metachronous gastric cancer (MGC), respectively.

RESULTS

During a median follow-up period of 6.0 years (interquartile range, 5.1-7.0), 30 OGCs and 61 MGCs were detected in 24 and 48 patients, respectively. The cumulative incidence of OGC at 1 year and MGC at 5 years was 7.6% and 12.7%, respectively. ER and gastrectomy were performed in 85 lesions and 6 lesions, respectively. Pathologic evaluation showed 78 mucosal cancers, 12 submucosal cancers, and 1 advanced cancer. Eventually, 28 OGCs and 52 MGCs fulfilled the pathologic criteria for curative ER.

CONCLUSIONS

Our study was the first to reveal the actual incidence of second gastric cancer after curative ER for differentiated-type gastric cancer. Most lesions could be treated with ER. Continuous endoscopic surveillance after curative ER is important to detect second gastric cancer.

Pretreatment risk factors for endoscopic noncurative resection of gastric cancers with undifferentiated-type components

BACKGROUND AND AIM

Endoscopic submucosal dissection (ESD) is recommended for the treatment of early gastric cancers with an undifferentiated-type component, clinically diagnosed as intramucosal lesions ≤ 2 cm, without ulceration. In the JCOG1009/1010 trial, ESD could be performed with stomach preservation in 70% of such patients whose pathological findings met the curative resection criteria. However, additional gastrectomy was required for the remaining 30%. We identified the pretreatment risk factors for noncurative resection.

METHODS

Post-hoc analysis indicated that 336 patients were identified in the JCOG1009/1010 trial; among them, 243 and 93 patients were categorized into the curative or noncurative resection groups, respectively, based on the pathological findings of the resected specimens. We explored the pretreatment risk factors for noncurative resection and investigated their associated pathological findings.

RESULTS

Multivariable analysis revealed that a pretreatment tumor size > 1 cm was an independent risk factor for noncurative resection (odds ratio, 3.538; 95% confidence interval, 2.020-6.198, P < 0.0001). Patients with a pretreatment tumor size > 1 cm (n = 172) had a histological tumor size > 2 cm (22.1% vs 4.3%, odds ratio, 6.313; 95% confidence interval, 2.73-14.599, P < 0.0001) and submucosal invasion (17.4% vs 9.1%, odds ratio, 2.000; 95% confidence interval, 1.032-3.877, P = 0.040) more frequently as noncurative resection findings compared with those with a tumor size < 1 cm (n = 164).

CONCLUSIONS

Because pretreatment tumor size > 1 cm is an independent risk factor for noncurative resection, endoscopists should be aware that noncurative resection is not uncommon in ESD and fully explain the potential necessity for additional gastrectomy to patients before the procedure.

Negative impact of intraoperative blood loss on long-term outcome after curative gastrectomy for advanced gastric cancer: exploratory analysis of the JCOG1001 phase III trial

BACKGROUND

Recent retrospective studies have shown that increased intraoperative blood loss (IBL) during curative gastrectomy for patients with advanced gastric cancer is a negative prognostic indicator for recurrence. However, there are no reliable reports assessing this with a large-scale prospective cohort. This study aimed to evaluate the impact of IBL on long-term outcomes using data from the JCOG1001 phase III trial, which was designed to determine if bursectomy led to improved survival vs. nonbursectomy in patients with cT3/4a gastric cancer.

METHODS

This study included 1203 of the 1204 patients enrolled in the JCOG1001. From the tertiles of IBL (196 ml, 400 ml), we divided the patients into three groups: IBL < 200 ml representing small blood loss (SBL, n = 404), 200 ml ≤ IBL < 400 ml representing medium blood loss (MBL, n = 393), and IBL ≥ 400 ml representing large blood loss (LBL, n = 406). The impact of IBL on relapse-free survival (RFS) was evaluated with univariable comparisons and multivariable Cox regression analyses.

RESULTS

Three-year RFS after SBL, MBL, and LBL was 81.7%, 74.8%, and 70.6%, respectively. Multivariable analysis identified IBL, Eastern Cooperative Oncology Group performance status, pT, pN, and postoperative adjuvant chemotherapy as independent predictors of RFS. Compared with SBL as a reference, the hazard ratios of MBL and LBL were 1.461 (P = 0.012) and 1.520 (P = 0.009), respectively.

CONCLUSIONS

Based on the analysis of data from a large-scale prospective study, an IBL of ≥ 200 ml after curative surgery for patients with cT3/4a gastric cancer was an independent predictor of reduced RFS.

Weekly Cisplatin Plus Radiation for Postoperative Head and Neck Cancer (JCOG1008): A Multicenter, Noninferiority, Phase II/III Randomized Controlled Trial

PURPOSE

The standard treatment for postoperative high-risk locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN) is chemoradiotherapy with 3-weekly cisplatin (100 mg/m²). However, whether chemoradiotherapy with weekly cisplatin (40 mg/m²) yields comparable efficacy with 3-weekly cisplatin in postoperative high-risk LA-SCCHN is unknown.

PATIENTS AND METHODS

In this multi-institutional open-label phase II/III trial, patients with postoperative high-risk LA-SCCHN were randomly assigned to receive either chemoradiotherapy with 3-weekly cisplatin (100 mg/m²) or with weekly cisplatin (40 mg/m²) to confirm the noninferiority of weekly cisplatin. The primary end point of phase II was the proportion of treatment completion, and that of phase III was overall survival. A noninferiority margin of hazard ratio was set at 1.32.

RESULTS

Between October 2012 and December 2018, a total of 261 patients were enrolled (3-weekly cisplatin, 132 patients; weekly cisplatin, 129 patients). At the planned third interim analysis in the phase III part, after a median follow-up of 2.2 (interquartile range 1.19-3.56) years, chemoradiotherapy with weekly cisplatin was noninferior to 3-weekly cisplatin in terms of overall survival, with a hazard ratio of 0.69 (99.1% CI, 0.374 to 1.273 [< 1.32], one-sided P for noninferiority = .0027 < .0043). Grade 3 or more neutropenia and infection were less frequent in the weekly arm (3-weekly v weekly, 49% v 35% and 12% v 7%, respectively), as were renal impairment and hearing impairment. No treatment-related death was reported in the 3-weekly arm, and two (1.6%) in the weekly arm.

CONCLUSION

Chemoradiotherapy with weekly cisplatin is noninferior to 3-weekly cisplatin for patients with postoperative high-risk LA-SCCHN. These findings suggest that chemoradiotherapy with weekly cisplatin can be a possible treatment option for these patients.

Abstract P3-16-04: Estimation of willingness-to-pay for breast cancer treatments through contingent valuation method in Japanese breast cancer patients (JCOG1709A): The main study findings

Background In 2019, the Japanese government has introduced the economic valuation to healthcare system. However, the threshold for determining cost-effectiveness-analysis has yet to be adequately studied. Therefore, we have designed a study to examine the financial value of “life” and “health” based on willingness-to-pay (WTP) considered by patients with primary and metastatic breast cancer (PBC and MBC) in Japan. Methods This study is conducted by forty-five hospitals under the Breast Cancer Study Group of Japan Clinical Oncology Group (JCOG). In the preliminary study, 168 patients (84 patients with PBC and 84 patients with MBC) from 20 to 79 years of age paying medical costs were examined their WTP for setting up the dichotomous-choice method survey form for using in the main study. Virtual scenario-specific treatments to avoid the recurrence and death of breast cancer for one year for PBC patients, and to prolong the survival period for one year for the patients with MBC were presented. The patients were evaluated how much money would pay to receive the treatment in a self-written answer and the amount of WTP that would be presented in the main study was determined. In the main study, 1,620 patients (810 patients with PBC and 810 patients with MBC) were surveyed to their WTP for hypothetical scenarios using the dichotomous-choice method survey form. With the two-step dichotomous-choice method, if the first stage response was yes, a higher amount was displayed for the second stage. If the first stage response was no, a lower amount was shown for the second stage. For the main analysis, the acceptance probability curve was calculated using the parametric method. The calculation was based on the obtained responses and median WTP, which was determined by calculating the amount at which the acceptance probability curve is at 50%. The obtained amount was converted to WTP per one QALY based on the displayed question content. Results Completed surveys were collected from 716 PBC patients (88.4%) and 702 patients (86.7%). Based on the preliminary study, the amount of WTP offering in the first stage was set 5 million yen (JPY) (50,000 USD), and offering in the second stage was 7 million JPY (70,000 USD) for those who responded accepting the scenario treatment and 3 million JPY (30,000 USD) for those who responded refusing. We obtained point estimates of WTP for each virtual scenario treatments. The WTP of the two hypothetical scenarios for PBC patients were as follows; scenario 1) the treatment to gain one year without recurrence: 2.06 million JPY (20,600 USD), scenario 2) the treatment that reduces risk of recurrence by 40%: 2.40 million JPY (24,000 USD). The WTP of the two hypothetical scenarios for MBC patients were as follows; scenario 3) the treatment that can prolong survival for one year in current health condition: 2.81 million JPY (28,100 USD), scenario 4) the treatment that can prolong survival by one year in the health condition before having breast cancer: 2.92 million JPY (29,200 USD). Conclusion We created hypothetical 1-quality-adjusted survival year (QALY) scenarios for breast cancer patients with different disease status and validated them using the contingent valuation method. Our results demonstrate that WTP per 1QALY varies with the disease status of breast cancer. Therefore, we conclude that we cannot simply use a uniform threshold when examining the cost-effectiveness of medical interventions in breast cancer as a unit of cost/QALY.

Citation Format: Tsuguo Iwatani, Fumikata Hara, Tadahiko Shien, Masato Takahashi, Norikazu Masuda, Yasuaki Sagara, Keita Sasaki, Junki Mizusawa, Haruhiko Fukuda, Takaru Shiroiwa, Hiroji Iwata. Estimation of willingness-to-pay for breast cancer treatments through contingent valuation method in Japanese breast cancer patients (JCOG1709A): The main study findings [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-16-04.

A randomized phase II trial of preoperative chemotherapy of S-1/CDDP with or without trastuzumab followed by surgery in HER2 positive advanced gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis: Japan Clinical Oncology Group study JCOG1301C (Trigger Study)

285

Background: The efficacy of trastuzumab has been established for HER2-positive advanced gastric cancer patients with metastatic disease. However, it remains unclear if the addition of trastuzumab to preoperative chemotherapy is effective for treatment of HER2-positive locally advanced gastric cancer. Methods: Eligible patients with HER2-positive gastric cancer with extensive lymph node metastasis were randomized to preoperative S-1/cisplatin (SP) (group A) or SP plus trastuzumab (group B). In both groups, patients received S-1, 80–120 mg/body, on days 1–14 and cisplatin, 60 mg/m2, on day 1, q21, 3-4 courses. Additionally, in group B, patients received infusions of trastuzumab (first course 8 mg/kg followed by 6 mg/kg, day 1). After gastrectomy, adjuvant chemotherapy with S-1 was performed for 1 year in both groups. The primary endpoint was overall survival, and the sample size was planned to be 130 patients in total, expecting a 10% increase in the 3-year overall survival (70% vs 80%) with a 1-sided alpha of 0.2, a power of 0.75. Results: The study was terminated in March 2021 due to slow patient accrual. In total, 46 patients were randomized to either group A (22 patients) or group B (24 patients). Patient characteristics were well balanced between the groups. Planned preoperative chemotherapy was completed in 20 patients (90.9%) in group A and in 23 patients (95.8%) in group B, and R0 resection was achieved in 20 patients (90.9%) in group A and 22 patients (91.7%) in group B. The incidences of grade 3 or 4 hematological/non-hematological adverse events during preoperative chemotherapy were 27.3/18.2% in group A and 4.2/8.3% in group B. Objective response rate (CR/PR) tended to be higher in group B (66.7% [16/24]) than in group A (36.4% [8/22], p = 0.08). Pathological response rate (> grade 1b in Japanese classification, 22.7% [5/22] vs. 50.0% [12/24], p = 0.07) and the proportion of patients achieving downstage to ypStage 0/I/II (22.7% [5/22] vs. 50.0% [12/24], p = 0.07) were also higher in group B than in group A. Conclusions: Preoperative chemotherapy with SP plus trastuzumab was feasible, and tended to show better radiological and pathological response rates. Better survival outcomes are expected by adding trastuzumab to preoperative chemotherapy with SP for locally advanced gastric cancer with extensive nodal metastasis. Clinical trial information: UMIN000016920.

Usefulness of an S-1 dosage formula: An exploratory analysis of randomized clinical trial (JCOG1001)

288

Background: Although the S-1 dose is determined by body surface area (BSA), its blood concentration and adverse events are affected by renal function. One study had reported the clinical utility of an S-1 dosage formula for calculating the dose for target blood concentration based on renal function (Booka E. Gastric Cancer 2016;19:876-86.). The present study aimed to explore the usefulness of this formula in adjuvant chemotherapy for gastric cancer. Methods: Ad hoc analyses was performed using data from patients enrolled in a phase III trial, JCOG1001, to evaluate the role of bursectomy for resectable advanced gastric cancer. In the abovementioned trial, patients with stage II/III received adjuvant S-1 chemotherapy based on BSA. The present study calculated the S-1 dose using the following formula: 1447.8 * (14.5+0.301*CLcr+8.23*SEX [male=1, female=0])*BSA (mg/day). Patients were divided into three groups, overdosed (OD), equal dosed (ED), and underdosed (UD), by comparing the initial dosage administered with that recommended by the formula. Results: Among the 686 eligible pts, 324, 304, and 58 were respectively classified as OD/ED/UD, with the following characteristics: median age, 67.5/64/53.5 years; men 188/229/57 (58%/75%/98%); undifferentiated type, 168/172/38 (52%/57%/66%); and pStage III, 212/200/41 (65%/66%/71%). Median relative dose intensity in OD/ED/UD pts was 93.8%/108.8%/75.0% based on the formula-recommended dose. The planned adjuvant S-1 therapy was completed in 69%/74%/74%, dose reduction and treatment schedule alteration were required in 31%/21%/9% and 20%/17%/9%, and treatment was terminated due to adverse events in 25%/18%/12%. The 5-year relapse-free (RFS) and overall survival (OS) OD/ED/UD patients were 66.6%/69.2%/74.0% and 77.0%/74.3%/77.3%, in pStage II 80.2%/85.6%/93.8% and 88.3%/90.1%/100%, and pStage III 59.6%/60.4%/65.8% and 67.0%/70.0%/67.7%, respectively. OD pts had significantly higher incidences of grade 3 or higher anemia, thrombocytopenia, diarrhea, stomatitis than ED and UD pts. Conclusions: Despite no difference in survival, this formula improved treatment compliance in OD patients receiving adjuvant S-1 chemotherapy for gastric cancer.[Table: see text]