Short- and long-term outcomes of surgical treatment for inguinal lymph node metastasis in rectal and anal canal adenocarcinoma.

AIM: The significance of lymphadenectomy and its indications in patients with inguinal lymph node metastasis (ILNM) of anorectal adenocarcinoma is unclear. This study aimed to clarify the surgical outcomes and prognostic factors of inguinal lymphadenectomy for ILNM. METHOD: This study included patients who underwent surgical resection for ILNM of rectal or anal canal adenocarcinoma with pathologically positive metastases between 1997 and 2011 at 20 participating centres in the Study Group for Inguinal Lymph Node Metastasis from Colorectal Cancer organized by the Japanese Society for Cancer of the Colon and Rectum. Clinicopathological characteristics and short- and long-term postoperative outcomes were retrospectively analysed. RESULTS: In total, 107 patients were included. The primary tumour was in the rectum in 57 patients (53.3%) and in the anal canal in 50 (46.7%). The median number of ILNMs was 2.34. Postoperative complications of Clavien-Dindo Grade III or higher were observed in five patients. The 5-year overall survival rate was 38.8%. Multivariate analysis identified undifferentiated histological type (P < 0.001), pathological venous invasion (P = 0.01) and pathological primary tumour depth T0-2 (P = 0.01) as independent prognostic factors for poor overall survival. CONCLUSION: The 5-year overall survival after inguinal lymph node dissection was acceptable, and it warrants consideration in more patients. Further larger-scale studies are needed in order to clarify the surgical indications.

Effect of Biologics on the Risk of Advanced-Stage Inflammatory Bowel Disease-Associated Intestinal Cancer: A Nationwide Study.

INTRODUCTION: The aim of this study was to evaluate the effect of biologics on the risk of advanced-stage inflammatory bowel disease (IBD)-associated intestinal cancer from a nationwide multicenter data set. METHODS: The medical records of patients with Crohn's disease (CD) and ulcerative colitis (UC) diagnosed with IBD-associated intestinal neoplasia (dysplasia or cancer) from 1983 to 2020 were included in this study. Therapeutic agents were classified into 3 types: biologics, 5-aminosalicylic acid, and immunomodulators. The pathological cancer stage was compared based on the drug used in both patients with CD and UC. RESULTS: In total, 1,042 patients (214 CD and 828 UC patients) were included. None of the drugs were significantly associated with cancer stage in the patients with CD. In the patients with UC, an advanced cancer stage was significantly associated with less use of biologics (early stage: 7.7% vs advanced stage: 2.0%, P < 0.001), 5-aminosalicylic acid, and immunomodulators. Biologic use was associated with a lower incidence of advanced-stage cancer in patients diagnosed by regular surveillance (biologics [-] 24.5% vs [+] 9.1%, P = 0.043), but this was not the case for the other drugs. Multivariate analysis showed that biologic use was significantly associated with a lower risk of advanced-stage disease (odds ratio = 0.111 [95% confidence interval, 0.034-0.356], P < 0.001). DISCUSSION: Biologic use was associated with a lower risk of advanced IBD-associated cancer in patients with UC but not with CD. The mechanism of cancer progression between UC and CD may be different and needs to be further investigated.

Clinicopathological features of appendiceal goblet cell adenocarcinoma in Japan: a multicenter retrospective study.

PURPOSE: In the 5th edition of the World Health Organization classification, appendiceal goblet cell adenocarcinoma (GCA) is categorized separately from neuroendocrine tumors and other appendiceal adenocarcinomas. We clarified the clinicopathological characteristics of Japanese appendiceal GCA. METHODS: We designed a retrospective multicenter cohort study and retrieved the data of patients with appendiceal neoplasms and histologically diagnosed appendiceal goblet cell carcinoid (GCC) treated from January 2000 to December 2017 in Japan. The available GCC slides were reviewed and diagnosed with a new grading system of GCA. RESULTS: A total of 922 patients from 43 institutions were enrolled; of these, 32 cases were patients with GCC (3.5%), and 20 cases were ultimately analyzed. The 5-year survival rate was 61.4% (95% confidence interval: 27.4-83.2), and the median survival time was 93.1 months. For peritoneal metastasis, regional lymph node metastasis was a significant factor (p = 0.04), and Grade 3 was a potential factor (p = 0.07). No peritoneal metastasis was observed in either T1/2 patients (n = 2) or Grade 1 patients (n = 4). We were unable to detect any significant factors associated with regional lymph node metastasis. CONCLUSION: For peritoneal metastasis, regional lymph node metastasis was a significant factor, and Grade 3 was a potential factor.

Impact of early tumor shrinkage on quality of life in patients treated with first-line cetuximab plus chemotherapy for unresectable metastatic colorectal cancer: results of Phase II QUACK trial.

PURPOSE: Although early tumor shrinkage (ETS) is a predictor of improved overall survival (OS), the association between ETS and health-related quality of life (HRQOL) remains unclear for patients with metastatic colorectal cancer (mCRC) treated with first-line cetuximab plus chemotherapy. METHODS: The data were collected from a prospective trial that assessed HRQOL using the EORTC QLQ-C30. The impact of ETS on HRQOL was estimated using a linear mixed-effects model for repeated measures. RESULTS: ETS was achieved in 82 (64.1%) of 128 mCRC patients treated with first-line cetuximab plus chemotherapy, and these patients had a significantly longer OS than those without ETS (HR, 0.38; 95% CI, 0.20-0.72; P = .002). Asymptomatic patients with ETS had a favorable OS, while symptomatic patients without ETS had a worse OS (2-year OS rates, 77.8% vs. 42.5%). Symptomatic patients with ETS had similar outcomes as asymptomatic patients without ETS (2-year OS rates, 64.1% vs. 67.0%). For symptomatic patients, ETS was associated with improved HRQOL scores between baseline and 8 weeks: the mean changes for patients with and without ETS were 5.86 and -4.94 for global health status (GHS)/QOL, 26.73 and 3.79 for physical functioning, and 13.58 and -3.10 for social functioning, respectively. The improved HRQOL was comparable to that of asymptomatic patients without ETS. For asymptomatic patients, ETS showed a decreased deterioration in HRQOL. CONCLUSION: Our findings highlight the importance of ETS for HRQOL and prognostic estimates, and assessing ETS may provide clinically useful information for physicians and patients to make more informed decisions.

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

AIM: The surgical treatment of inguinal lymph node (ILN) metastases secondary to anorectal adenocarcinoma remains controversial. This study aimed to clarify the surgical treatment and management of ILN metastasis according to its classification. METHODS: This retrospective, multi-centre, observational study included patients with synchronous or metachronous ILN metastases who were diagnosed with rectal or anal canal adenocarcinoma between January 1997 and December 2011. Treatment outcomes were analysed according to recurrence and prognosis. RESULTS: Among 1181 consecutively enrolled patients who received treatment for rectal or anal canal adenocarcinoma at 20 referral hospitals, 76 (6.4%) and 65 (5.5%) had synchronous and metachronous ILN metastases, respectively. Among 141 patients with ILN metastasis, differentiated carcinoma, solitary ILN metastasis and ILN dissection were identified as independent predictive factors associated with a favourable prognosis. No significant difference was found in the frequency of recurrence after ILN dissection between patients with synchronous (80.6%) or metachronous (81.0%) ILN metastases. Patients who underwent R0 resection of the primary tumour and ILN dissection had a 5-year survival rate of 41.3% after ILN dissection (34.1% and 53.1% for patients with synchronous and metachronous ILN metastases, respectively, P = 0.55). CONCLUSION: The ILN can be appropriately classified as a regional lymph node in rectal and anal canal adenocarcinoma. Moreover, aggressive ILN dissection might be effective in improving the prognosis of low rectal and anal canal adenocarcinoma with ILN metastases; thus, prophylactic ILN dissection is unnecessary.

Primary tumor location as a predictor of survival in patients with RAS wild-type colorectal cancer who receive molecularly targeted drugs as first-line therapy: a multicenter real-world observational study by the Japanese Society for Cancer of the Colon and Rectum.

BACKGROUND: Primary tumor location is considered a predictor of overall survival (OS) in RAS wild-type (WT) metastatic colorectal cancer (mCRC) treated with bevacizumab (BEV) or an anti-epidermal growth factor antibody (cetuximab or panitumumab [CET/PAN]) as first-line molecularly targeted therapy. BEV is recommended for right-sided mCRC and CET/PAN for left-sided mCRC based on post-hoc analyses of clinical trial data, but real-world evidence is lacking. METHODS: We retrospectively collected data of patients who started BEV or CET/PAN plus 5-fluorouracil-based doublet chemotherapy between January 2013 and December 2016 as first-line treatment for RAS WT mCRC at any of 24 Japanese institutions. OS was compared between the BEV and CET/PAN groups according to primary tumor location by Cox multivariate regression analysis in the full cohort and in a propensity score-matched cohort. RESULTS: In total, 935 patients were enrolled. Median OS was 24.6 months with BEV and 20.9 months with CET/PAN in right-sided mCRC (n = 213; adjusted hazard ratio [HR] 0.73, 95% confidence interval [CI] 0.50-1.06) and 35.7 months and 30.0 months, respectively, in left-sided mCRC (n = 722; adjusted HR 0.92, 95% CI 0.74-1.13). In the propensity score-matched cohort, OS was significantly better in the BEV group than in the CET/PAN group in right-sided mCRC (HR 0.52, 95% CI 0.28-0.96) but was not significantly different in left-sided mCRC (HR 0.78, 95% CI 0.53-1.07). CONCLUSION: Real-world data showed that OS was better with BEV than with CET/PAN in right-sided mCRC. However, there was no significant difference in OS in left-sided mCRC.

Clinicopathological Characteristics of Low-Grade Appendiceal Mucinous Neoplasm.

INTRODUCTION: Recently, "low-grade appendiceal mucinous neoplasms" (LAMNs) have been proposed as one subtype of appendiceal mucinous neoplasms, characterized by a villous or flat proliferation of mucinous epithelium with low-grade cytologic atypia. The aim of this study was to clarify the clinicopathological characteristics of LAMN. METHODS: In this multi-institutional cohort study, we retrospectively analyzed the clinicopathological characteristics in appendiceal neoplasms patients who underwent treatment from 2000 to 2017. RESULTS: In total, 922 patients were enrolled, with 279 (30.3%) cases of LAMN, and 93 (10.1%) cases of non-LAMN disease. In comparison with patients with non-LAMN disease, those with LAMN had significantly lower levels of CA19-9 (p = 0.045), a lower frequency of T4 tumors (p < 0.0001), a lower frequency of lymph node metastasis (p < 0.0001), and a lower frequency of distant metastasis (p < 0.0001). Survival analysis revealed that patients with LAMN had a significantly better prognosis than did those with non-LAMN disease (p < 0.001). Among the patients with distant metastasis, those with LAMN had a significantly better prognosis than did those with non-LAMN disease (p = 0.0020), but among the patients without distant metastasis, the difference between the 2 groups was not significant (p = 0.26). However, among patients who underwent complete resection, the difference in prognosis between the 2 groups was not significant (p = 0.10). CONCLUSIONS: A multicenter retrospective study revealed that the clinicopathological characteristics of LAMN was different from those of non-LAMN.

Phase 2 study of irinotecan plus cetuximab rechallenge as third-line treatment in KRAS wild-type metastatic colorectal cancer: JACCRO CC-08.

BACKGROUND: Regorafenib or trifluridine/tipiracil as third-line treatment have limited efficacy in metastatic colorectal cancer (mCRC). METHODS: This Phase 2 trial evaluated the efficacy and safety of irinotecan plus cetuximab rechallenge as third-line treatment in KRAS wild-type mCRC patients who achieved clinical benefit with first-line cetuximab-containing therapy. The primary endpoint was 3-month progression-free survival (PFS) rate. A sample size was calculated; 30 patients with a 3-month PFS rate of 45% deemed promising and 15% unacceptable. Patients with greater and less than the cut-off value of cetuximab-free intervals (CFIs) were classified into the long and short CFI groups, respectively, in subgroup analyses. RESULTS: Among 34 eligible patients who received treatment at least once, 3-month PFS rate was 44.1% (95% confidence interval, 27.4-60.8%). The median PFS and overall survival (OS) were 2.4 and 8.2 months, respectively. The response and disease control rates were 2.9 and 55.9%, respectively. PFS and OS were significantly longer in the long- than in the short CFI group. CONCLUSIONS: Irinotecan plus cetuximab rechallenge as third-line treatment for KRAS wild-type mCRC was safe and had promising activity, especially in those with a long CFI, warranting further investigation in a Phase 3 randomised trial. CLINICAL TRIAL REGISTRATION: UMIN000010638.

Factors affecting R0 resection of colorectal cancer with synchronous peritoneal metastases: a multicenter prospective observational study by the Japanese Society for Cancer of the Colon and Rectum.

BACKGROUND: In Japan, R0 resection has been recommended for colorectal cancer patients with peritoneal metastases confined to the adjacent peritoneum and those with a few metastases to the distant peritoneum. R0 resection for M1c disease has drawn attention in Western countries and is currently considered an acceptable therapeutic option in the US National Comprehensive Cancer Network guidelines. However, clinical factors that affect the choice of R0 resection are unknown. METHODS: This multicenter, prospective, observational study was conducted by the Japanese Society for Cancer of the Colon and Rectum. Colorectal cancer patients with synchronous peritoneal metastases were enrolled at 28 institutions in Japan from October 2012 to December 2016. To determine factors affecting R0 resection and R1 resection with intended R0 resection, stepwise logistic regression analyses were performed on clinical factors including age, sex, performance status (PS), body mass index, peritoneal cancer index (PCI) score, presence of ascites, presence of distant metastases, and primary tumor site. RESULTS: R0/R1 resection was performed in 36 (31/5; 25%) of 146 patients. No distant metastases [odds ratio (OR) 52.9; 95% confidence interval (CI) 13.3-210.1; p < 0.0001], low PCI score (1-6) (OR 20.0; 95% CI 4.8-83.4; p < 0.0001), and high PS (0) (OR 2.40; 95% CI 0.66-8.68; p = 0.18) were independent factors affecting R0/R1 resection. PCI score and PS were also independent factors affecting R0/R1 resection in M1c patients without non-peritoneal distant metastases (n = 59). CONCLUSION: Distant metastases, PCI score, and PS are three factors which affect R0 resection for M1c disease.

Prognostic scores for evaluating the survival benefit of regorafenib or trifluridine/tipiracil in patients with metastatic colorectal cancer: an exploratory analysis of the REGOTAS study.

BACKGROUND: Although regorafenib or trifluridine/tipiracil (FTD/TPI) has been recognized as a later-line standard treatment in patients with metastatic colorectal cancer (mCRC), not all patients have beneficial outcomes. This study aimed to develop a prognostic scoring system for evaluating the overall survival (OS) benefit. METHODS: Patients included in the REGOTAS study, which comprised 489 patients (regorafenib group: 199; FTD/TPI group: 290 patients), were evaluated. OS was analyzed using multivariate Cox proportional model. The prognostic score was calculated using the worst four individual factors weighted by hazard ratio, and the total scores were categorized as low-, moderate-, and high-OS benefit. RESULTS: The worst four factors in the regorafenib group were AST > 40 IU/dL (point, + 3), CRP ≥ 1.0 mg/dL (+ 2), number of metastatic organ site ≥ 3 (+ 2), and duration from initiation of 1st-line chemotherapy < 18 months (+ 2), while they were AST (+ 2), CRP (+ 2), CA19-9 > 37.0 U/mL (+ 2), and ECOG PS ≥ 1 (+ 2) in the FTD/TPI group. These corresponded to a total prognostic score of > 5, 2-4, and 0 points in the regorafenib group and 8, 2-6, and 0 points in the FTD/TPI group. The median OS in the low, moderate, and high OS benefit group was 3.3 (95% CI 3.0-3.7), 8.1 (95% CI 6.4-9.7), and 12.6 months (95% CI 10.6-14.6) in the regorafenib group and 2.8 (95% CI 2.0-3.5), 7.5 (95% CI 6.6-8.3), and 15.4 months (95% CI 9.7-21.2) in the FTD/TPI group. CONCLUSION: These prognostic scores are useful for identifying patients with mCRC who will obtain survival benefits from these drugs.

Propensity Score Analysis of Regorafenib Versus Trifluridine/Tipiracil in Patients with Metastatic Colorectal Cancer Refractory to Standard Chemotherapy (REGOTAS): A Japanese Society for Cancer of the Colon and Rectum Multicenter Observational Study.

BACKGROUND: This study compared the efficacy of regorafenib and trifluridine/tipiracil (TFTD) in patients with metastatic colorectal cancer (mCRC) who are refractory to standard chemotherapy, because despite their clinical approval, it still remains unclear which of these two drugs should be used as initial treatment. MATERIALS AND METHODS: The clinical data of patients with mCRC who were treated with regorafenib or TFTD and those of drug-naive patients, between June 2014 and September 2015, were retrospectively collected from 24 institutions in Japan. Overall survival (OS) was evaluated using the Cox's proportional hazard models based on propensity score adjustment for baseline characteristics. RESULTS: A total of 550 patients (223 patients in the regorafenib group and 327 patients in the TFTD group) met all criteria. The median OS was 7.9 months (95% confidence interval [CI], 6.8-9.2) in the regorafenib group and 7.4 months (95% CI, 6.6-8.3) in the TFTD group. The propensity score adjusted analysis showed that OS was similar between the two groups (adjusted hazard ratio [HR], 0.96; 95% CI, 0.78-1.18). In the subgroup analysis, a significant interaction with age was observed. Regorafenib showed favorable survival in patients aged <65 years (HR, 1.29; 95% CI, 0.98-1.69), whereas TFTD was favored in patients aged ≥65 years (HR, 0.78; 95% CI, 0.59-1.03). CONCLUSION: No significant difference in OS between regorafenib and TFTD was observed in patients with mCRC. Although the choice of the drug by age might affect survival, a clearly predictive biomarker to distinguish the two drugs should be identified in further studies. IMPLICATIONS FOR PRACTICE: Previous studies of patients with metastatic colorectal cancer refractory to standard chemotherapy had demonstrated that both regorafenib and trifluridine/tipiracil could result in increased overall survival compared with placebo, but there are no head-to-head trials. This large, multicenter, observational study retrospectively compared the efficacy of regorafenib and trifluridine/tipiracil in 550 patients with metastatic colorectal cancer refractory to standard chemotherapy who had access to both drugs. Although no difference in overall survival was found between the two drugs in adjusted analysis using propensity score, regorafenib showed favorable survival in patients aged <65 years, whereas trifluridine/tipiracil was favored in patients aged ≥65 years in the subgroup analysis.

Preplanned safety analysis of the JFMC37-0801 trial: a randomized phase III study of six months versus twelve months of capecitabine as adjuvant chemotherapy for stage III colon cancer.

BACKGROUND: Six months of adjuvant chemotherapy is regarded as the standard of care for patients with stage III colon cancer. However, whether longer treatment can improve prognosis has not been fully investigated. We conducted a phase III study comparing 6 and 12 months of adjuvant capecitabine chemotherapy for stage III colon cancer, and report here the results of our preplanned safety analysis. METHODS: Patients aged 20-79 years with curatively resected stage III colon cancer were randomly assigned to receive 8 cycles (6 months) or 16 cycles (12 months) of capecitabine (2500 mg/m2/day on days 1-14 of each 21-day cycle). Treatment exposure and adverse events (AEs) were evaluated. RESULTS: A total of 1304 patients (642 and 636 in the 6-month and 12-month groups, respectively) were analyzed. The most common AE was hand-foot syndrome (HFS). HFS, leukocytopenia, neutropenia, and hyperbilirubinemia (any grade) occurred more frequently in the 12-month group than in the 6-month group. HFS was the only grade ≥3 AE to have a significantly higher incidence in the 12-month group (23 vs 17%, p = 0.011). The completion rate for 8 cycles was 72% in both groups, while that for 16 cycles was 46% in the 12-month group. HFS was the most common AE requiring dose reduction and treatment discontinuation. CONCLUSIONS: Twelve months of adjuvant capecitabine demonstrated a higher cumulative incidence of HFS compared to the standard 6-month treatment period, while toxicities after 12 months of capecitabine were clinically acceptable. TRIAL REGISTRATION: UMIN-CTR, UMIN000001367.

[Port site recurrence after thoracoscopic resection of the pulmonary metastasis of sigmoid colon cancer].

A 71-year-old female underwent thoracoscopic resection for pulmonary metastasis from sigmoid colon cancer in March 2012. After 7 months, postoperative computed tomography (CT) showed a chest tumor around the left 6th rib. At the same time, she complained of left chest pain. These findings were initially considered as posttreatment changes. But the lesion of the chest wall enlarged and the pain worsened. We made a diagnosis of chest wall recurrence and performed a surgery in June 2013. The pathological diagnosis was chest wall metastasis from colon cancer. A port site recurrence on the chest wall was strongly suggested because it was extremely close to the port site of thoracoscopic resection. This patient is free from recurrence 16 months after surgery.

Phase II trial of cetuximab plus irinotecan for oxaliplatin- and irinotecan-based chemotherapy-refractory patients with advanced and/or metastatic colorectal cancer: evaluation of efficacy and safety based on KRAS mutation status (T-CORE0801).

BACKGROUND: Mutations in the KRAS gene have been identified as negative predictors of response to anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy by patients with metastatic colorectal cancer (mCRC). However, it has been based on the study of mainly Caucasian mCRC patients. This prospective study investigated the relationship between the mutation status of EGFR-related genes including KRAS and the response rate (RR) to cetuximab plus irinotecan therapy in Japanese mCRC patients. METHODS: Samples taken from 43 chemotherapy-refractory mCRC patients who had undergone cetuximab plus irinotecan therapy at 11 medical centers in Japan were subjected to direct DNA sequencing to determine the KRAS, BRAF, PIK3CA, NRAS, and AKT1 mutation status. The clinical outcome after the treatment was evaluated for each mutation status. RESULTS: KRAS mutations were detected in 31.7% of 41 eligible patients. The RR to cetuximab plus irinotecan therapy was found to be 17.9 and 0% in the KRAS wild-type and mutant subgroups, respectively. CONCLUSION: Despite the identification of a lower-than-expected RR to treatment by the KRAS wild-type subgroup, KRAS mutation status appears to be a useful predictive marker of response to cetuximab plus irinotecan therapy in Japanese mCRC patients.

Lymphatic spread patterns in young versus elderly patients with stage III colon cancer.

BACKGROUND: The anatomical pattern of lymph nodes spread differs between young (aged 45 years or younger) and elderly (aged 80 years or older) patients with stage III colon cancer and is poorly investigated. METHODS: Two groups of patients (young and elderly) with stage III colon cancer who underwent upfront extensive (D3) lymphadenectomy at eight Japanese centres between 1998 and 2018 were retrospectively analysed. The primary endpoint was the proportion of positive central lymph nodes. The lymph nodes spreading pattern and its prognostic impact on recurrence-free survival and overall survival in the two groups were also compared. RESULTS: Two hundred and ten young patients and 348 elderly patients were identified and compared. The total number of lymph nodes harvested and the total number of invaded lymph nodes were significantly higher in younger patients compared with elderly patients (median of 31.5 (3-151) versus 21 (3-116), P < 0.001 and median of 3 (1-21) versus 2 (1-25), P < 0.001 respectively). The proportion of positive central lymph nodes were higher in younger patients than in elderly patients (9.52% (95% c.i. 6.24 to 14.2%) versus 4.59% (95% c.i. 2.84 to 7.31%), P = 0.012). In multivariate models for recurrence-free survival, central lymph nodes invasion were identified as a poor prognostic factor in younger patients (HR 5.21 (95% c.i. 1.76 to 15.39)) but not in elderly patients (HR 1.73 (95% c.i. 0.80 to 3.76)). CONCLUSION: Young patients with stage III colon cancer have a higher risk of central lymph nodes invasion, suggesting a more aggressive disease biology. The presence of central lymph nodes invasion are associated with a worse outcome in young patients.

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

Aim: The aim of this study was to clarify the significance of resection of ovarian metastases from colorectal cancer and to identify the clinicopathologic characteristics. Methods: In this multicenter retrospective study, we evaluated data on ovarian metastases from colorectal cancer obtained from patients at 20 centers in Japan between 2000 and 2014. We examined the impact of resection on the prognosis of patients with ovarian metastases and examined prognostic factors. Results: The study included 296 patients with ovarian metastasis. The 3-y overall survival rate was 68.6% for solitary ovarian metastases. In all cases of this cohort, the 3-y overall survival rates after curative resection, noncurative resection, and nonresection were 65.9%, 31.8%, and 6.1%, respectively (curative resection vs noncurative resection [P < 0.01] and noncurative resection vs nonresection [P < 0.01]). In the multivariate analysis of prognostic factors, tumor size of ovarian metastasis (P < 0.01), bilateral ovarian metastasis (P = 0.01), peritoneal metastasis (P < 0.01), pulmonary metastasis (P = 0.04), liver metastasis (P < 0.01), and remnant of ovarian metastasis (P < 0.01) were statistically significantly different. Conclusion: The prognosis after curative resection for solitary ovarian metastases was shown to be relatively favorable as Stage IV colorectal cancer. Resection of ovarian metastases, not only curative resection but also noncurative resection, confers a survival benefit. Prognostic factors were large ovarian metastases, bilateral ovarian metastases, the presence of extraovarian metastases, and remnant ovarian metastases.

Monitoring ctDNA RAS Mutational Status in Metastatic Colorectal Cancer: A Trial Protocol of RAS-trace and RAS-trace-2 Studies.

Background: Spatial and temporal heterogeneities of RAS and other molecular genes should be considered in the treatment of metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs); acquired RAS mutation is sometimes observed at disease progression of treatment with the anti-EGFR mAb. At the same time, discrepancy of RAS status from tissues and circulating tumor DNA (ctDNA) in the same patient is sometimes observed. Based on this, we commenced two observational studies to clarify these heterogeneities of RAS and BRAF in mCRC, using next generation sequencing from liquid biopsy. Methods/Design: RAS-trace study is an observational study to monitor ctDNA RAS/BRAF/PIK3CA status every 4-12 weeks using the Plasma-SeqSensei™ CRC RUO Kit (Sysmex Inostics GmbH) in mCRC with RAS/BRAF wild-type (wt) on tumor tissue. The primary endpoint was the time to the acquired RAS mutations. A total of 42 patients has been accrued. RAS-trace-2 study is also an observational study aimed at comparing the efficacy of the anti-EGFR mAb in ctDNA RAS/BRAF wt with ctDNA RAS or BRAF mutant mCRC patients, whose RAS/BRAF are wt in tumor tissue. The primary endpoint was progression-free survival in patients with ctDNA RAS/BRAF wt and RAS or BRAF mutant. A total of 240 patients will be accrued over 2 years. Discussion: These trials will help us understanding the clinical significance of spatial and temporal heterogeneities of RAS, BRAF and other genes, while optimizing the anti-EGFR mAb treatment strategies in mCRC.

A multicenter cohort study on mapping of lymph node metastasis for splenic flexural colon cancer.

Aim: There have been no reports of searching for metastases to lymph nodes along the accessory middle colic artery (aMCA). The aim of this study was to investigate the metastasis rate of the aMCA for splenic flexural colon cancer. Methods: Patients with histologically proven colon carcinoma located in the splenic flexure, clinically diagnosed as stage I-III were eligible for this study. Patients were retrospectively and prospectively enrolled. The primary endpoint was frequency of lymph node metastasis to the aMCA (station 222-acc and 223-acc). The secondary endpoint was the frequency of lymph node metastasis to the middle colic artery (MCA) (station 222-lt and 223) and left colic artery (LCA) (station 232 and 253). Results: Between January 2013 and February 2021, a total of 153 consecutive patients were enrolled. The location of the tumor was 58% in the transverse colon and 42% in the descending colon. Lymph node metastases were observed in 49 cases (32%). The presence of aMCA rate was 41.8% (64 cases). The metastasis rates of stations 221, 222-lt, and 223 were 20.0%, 1.6%, and 0%, and stations 231, 232, and 253 were 21.4%, 1.0%, and 0%, respectively. The metastasis rates of stations 222-acc and 223-acc were 6.3% (95% confidence interval: 1.7%-15.2%) and 3.7% (95% confidence interval: 0.1%-19%), respectively. Conclusions: This study identified the distribution of lymph node metastases from splenic flexural colon cancer. If the aMCA is present, this vessel should be targeted for dissection, taking into account the frequency of lymph node metastasis.

Phase II study of biweekly cetuximab plus mFOLFOX6 or mFOLFIRI as second-line treatment for metastatic colorectal cancer and exploratory analysis of associations between DNA methylation status and the efficacy of the anti-EGFR antibody: T-CORE1201.

Background: Little is known about the biweekly combined use of cetuximab and chemotherapy as second-line treatment of metastatic colorectal cancer (mCRC). Recently, DNA methylation status has been reported to be a new possible predictor of the efficacy from the anti-epidermal growth factor receptor (EGFR) antibody treatment. The purpose of this study was to examine the efficacy and safety of biweekly cetuximab plus mFOLFOX6 or mFOLFIRI as a second-line treatment for KRAS exon 2 wild-type mCRC. We also investigated the predictability of DNA methylation status on the efficacy of the EGFR antibody-containing treatment. Methods: Patients who were refractory or intolerant to the first-line chemotherapy were enrolled and received biweekly cetuximab plus mFOLFOX6 or mFOLFIRI. The primary endpoint was progression-free survival (PFS). Tumor evaluations were performed every 2 months using Response Evaluation Criteria in Solid Tumor (RECIST) version 1.1. Adverse events (AEs) were evaluated according to the Common Terminology Criteria for Adverse Events version 4.0. DNA methylation status of colorectal cancer cells was defined by a modified MethyLight assay. Results: Sixty-six cases were enrolled. The median PFS (mPFS) was 5.1 [95% confidence interval (CI), 3.8-7.6] months. The median overall survival (mOS) was 12.7 (95% CI, 7.5-15.3) months. Grade 3 or higher neutropenia occurred in 53.0% of patients, whereas skin disorders with a grade 3 or higher occurred in <15% of patients. In multivariate analysis, DNA methylation status could not be an independent predictor of PFS [hazard ratio (HR), 1.43; P=0.39] and OS (HR, 2.13; P=0.086). However, in RAS/BRAF wild-type patients, the mPFS and mOS in the low-methylated colorectal cancer (LMCC) group was numerically better than those in the highly-methylated colorectal cancer (HMCC) group, although the difference was not statistically significant [mPFS: 8.5 (95% CI, 6.1-10.9) vs. 3.3 (95% CI, 1.2-not reached) months, P=0.79; ΔmPFS, 5.2 months; mOS: 15.3 (95% CI, 11.9-23.5) vs. 6.5 (95% CI, 3.1-not reached) months, P=0.53; ΔmOS, 8.8 months]. Conclusions: Biweekly cetuximab plus mFOLFOX6 or mFOLFIRI is a useful second-line therapy for mCRC. DNA methylation status warrants further exploration as a predictive biomarker for anti-EGFR efficacy in mCRC.

A proposed new Japanese classification of synchronous peritoneal metastases from colorectal cancer: A multi-institutional, prospective, observational study conducted by the Japanese Society for Cancer of the Colon and Rectum.

Aim: To establish a new Japanese classification of synchronous peritoneal metastases from colorectal cancer. Methods: This multi-institutional, prospective, observational study enrolled patients who underwent surgery for colorectal cancer with synchronous peritoneal metastases. Overall survival rates were compared according to the various models using objective indicators. Each model was evaluated by Akaike's information criterion (AIC). The region of peritoneal metastases was evaluated by the peritoneal cancer index (PCI). Results: Between October 2012 and December 2016, 150 patients were enrolled. The AIC of the present Japanese classification was 1020.7. P1 metastasis was defined as confined to two regions. The minimum AIC was obtained with the cutoff number of 10 or less for P2 metastasis and 11 or more for P3 metastasis. As for size, the best discrimination ability between P2 and P3 metastasis was obtained with a cutoff value of 3 cm. The AIC of the proposed classification was 1014.7. The classification was as follows: P0, no peritoneal metastases; P1, metastases localized to adjacent peritoneum (within two regions of PCI); P2, metastases to distant peritoneum, number ≤10 and size ≤3 cm; P3, metastases to distant peritoneum, number ≥11 or size >3 cm; P3a, metastases to distant peritoneum, number ≥11 and size ≤3 cm, or number ≤10 and size >3 cm; P3b, metastases to distant peritoneum, number ≥11 and size >3 cm. Conclusion: This objective classification could improve the ability to discriminate prognosis in patients with synchronous peritoneal metastases from colorectal cancer.