Predictive score for identifying intrahepatic cholangiocarcinoma patients without lymph node metastasis: a basis for omitting lymph node dissection.

BACKGROUND: This study aimed to develop a predictive score for intrahepatic cholangiocarcinoma (ICC) in patients without lymph node metastasis (LNM) using preoperative factors. METHODS: A retrospective analysis of 113 ICC patients who underwent liver resection with systemic lymph node dissection between 2002 and 2021 was conducted. A multivariate logistic regression analysis was used as a predictive scoring system for node-negative patients based on the ß coefficients of preoperatively available factors. RESULTS: LNM was observed in 36 patients (31.9%). Four factors were associated with LNM: suspicion of LNM on MDCT (odds ratio [OR] 13.40, p < 0.001), low-vascularity tumor (OR 6.28, p = 0.005), CA19-9 ≥500 U/mL (OR 5.90, p = 0.010), and tumor location in the left lobe (OR 3.67, p = 0.057). The predictive scoring system was created using these factors (assigning 3 points for suspected LNM on MDCT, 2 points for CA19-9 ≥500 U/mL, 2 points for low vascularity tumor, and 1 point for tumor location in the left lobe). A score cutoff value of 4 resulted in 0.861 sensitivity and a negative predictive value of 0.922 for detecting LNM. Notably, no patients with peripheral tumors and a score of ≤3 had LNM. CONCLUSION: The developed scoring system may effectively help identify ICC patients without LNM.

Efficacy of lymph node dissection for duodenal cancer according to the lymph node station.

Background: Lymph node metastasis (LNM) is associated with poor prognosis in patients with duodenal cancer (DC). However, the efficacy and optimal extent of lymph node (LN) dissection have not been thoroughly discussed. Methods: A total of 98 consecutive patients with DC who underwent surgical resection (pancreatoduodenectomy, n = 55; partial resection, n = 32; pancreas-sparing total duodenectomy, n = 9) were retrospectively analyzed. The LN stations located upstream of the lymphatic flow were defined as Np stations according to tumor location, whereas the others were defined as Nd stations. The association between the dissection of each LN station and survival outcome was investigated using the efficacy index (EI; percentage of metastases to lymph nodes in each station multiplied by the 5-year survival rate of metastatic cases). Results: The survival of patients with LNM at the Nd stations (n = 6) was significantly worse than that of patients with LNM only at the Np stations (n = 20) (relapse-free survival, median survival time [MST], 6.0 vs. 48.4 months, p < 0.001; overall survival, MST, 15.1 vs. 96.0 months, p < 0.001). Multivariate analysis identified LNM at Nd stations as an independent prognostic factor for overall survival (hazard ratio 9.92; p = 0.015). The Np stations had a high EI (range, 8.34-20.88), whereas the Nd stations had an EI of 0, regardless of the tumor location. Conclusions: LN dissection of the Np stations contributed to acceptable survival, whereas LNM of the Nd stations led to poor survival, possibly reflecting advanced tumor progression to systemic disease in patients with DC.

Tumor vascularity on contrast-enhanced computed tomography as a predictive marker of metastatic potential for small nonfunctioning pancreatic neuroendocrine tumors.

BACKGROUND: Although surgical resection is generally suggested for nonfunctioning pancreatic neuroendocrine tumors, observation can be proposed for carefully selected patients with small tumors. However, the indications for observation remain unclear. METHODS: This retrospective study included 77 patients with nonfunctioning pancreatic neuroendocrine tumors, including small tumors (≤2.0 cm, n = 41), who received pancreatectomy. The ratio of the mean computed tomography value of a tumor in the late arterial/equilibrium phase (computed tomography a/e ratio) was used to evaluate tumor vascularity. Pathologic examinations of small tumors were conducted. The associations among the computed tomography a/e ratio, pathologic findings, and survival outcomes were investigated. RESULTS: Small tumors were pathologically categorized by the degree of fibrosis as follows: medullary (n = 20), intermediate (n = 11), and fibrotic (n = 10). The fibrotic type had significantly lower computed tomography a/e ratios than the medullary type (median, 1.42 vs 2.03, P < .001). The median number of vessels with microscopic venous invasion was significantly higher in the fibrotic type than in the medullary type (4.5 vs 0.0, P < .001). The cutoff value of the computed tomography a/e ratio for predicting microscopic venous invasion was determined to be 1.54 by the receiver operating characteristic curve (area under the curve, 0.832; sensitivity, 80.0%; specificity, 83.9%; accuracy, 82.9%). Microscopic venous invasion was an independent prognostic factor for relapse-free survival in overall patients (hazard ratio 5.18, P = .017). CONCLUSION: The computed tomography a/e ratio may be a useful predictor of the metastatic potential of nonfunctioning pancreatic neuroendocrine tumors and may help decide the indications of observation for small nonfunctioning pancreatic neuroendocrine tumors.

Prognostic impact of the distance from the root of splenic artery to tumor in the patients with pancreatic body or tail cancer.

BACKGROUND: The impact of the distance from the root of splenic artery to tumor (DST) on the prognosis and optimal surgical procedures in the patients with pancreatic body/tail cancer has been unclear. METHODS: We retrospectively analyzed 94 patients who underwent distal pancreatectomy (DP) and 17 patients who underwent DP with celiac axis resection (DP-CAR) between 2008 and 2018. RESULTS: The 111 patients were assigned by DST length (in mm) as DST = 0: n = 14, 0

Benefit of lymph node dissection for perihilar and distal cholangiocarcinoma according to lymph node stations.

BACKGROUND: The benefits of lymph node (LN) dissection at each station have not previously been fully investigated in perihilar cholangiocarcinoma (PHCC) and distal cholangiocarcinoma (DCC). METHODS: The efficacy index (EI) was calculated in patients who underwent surgery for PHCC (n = 134) and DCC (n = 135) by multiplying the frequency of metastasis to the LN station and the 5-year overall survival (OS) rate of patients with metastasis to that station. RESULTS: In PHCC, the frequency of metastasis, 5-year OS rates, and the EI in para-aortic LNs (4.7%, 0%, and 0, respectively) and posterior pancreaticoduodenal LNs (8.1%, 0%, and 0, respectively) were lower than those in hepatoduodenal ligament LNs (30.1%, 24.1%, and 7.25, respectively) and LNs along the common hepatic artery (CHA) (16.2%, 15.0%, and 2.43, respectively). In DCC, these values were lower in LNs along the CHA (6.4%, 0%, and 0, respectively) than in the posterior pancreaticoduodenal LNs (31.2%, 34.5%, and 10.8, respectively), the hepatoduodenal ligament LNs (14.8%, 15.2%, and 2.25, respectively), and para-aortic (4.0%, 25.0%, and 0.99, respectively) LNs. CONCLUSIONS: According to the EI, this study raises concerns about the effectiveness of dissection in the posterior pancreaticoduodenal LNs in PHCC and LNs along the CHA in DCC.

Comparison of Cefazolin and Ceftriaxone as Antimicrobial Prophylaxis in Pancreatoduodenectomy with Preoperative Drainage: Incidence of Surgical Site Infection and Susceptibility of Bacteria in Bile.

BACKGROUND: The optimal perioperative antimicrobial agent for preventing surgical site infection (SSI) in pancreatoduodenectomy (PD) with preoperative biliary drainage (PBD) remains unclear. METHODS: We retrospectively reviewed 288 patients who underwent PD after PBD between 2010 and 2020 at our institution. Patients were classified into two groups according to the perioperative antimicrobial agent used (cefazoline [CEZ] group [n = 108] and ceftriaxone [CTRX] group [n = 180]). The incidence of SSI, type of bacteria in intraoperative bile culture (IBC), and antimicrobial susceptibility to prophylactic antimicrobial agents were analyzed. RESULTS: The incidence of incisional SSI was significantly lower in the CTRX group than in the CEZ group (18% vs. 31%, P = 0.021), whereas the incidence of organ/space SSI in the two groups did not differ to a statistically significant extent (35% vs. 44%, P = 0.133). Gram-negative rod (GNR) bacteria in the IBC showed better antimicrobial susceptibility in the CTRX group than in the CEZ group. In multivariate analysis, antimicrobial resistance due to GNR was a significant risk factor for incisional SSI (odds ratio, 3.50; P < 0.001). CONCLUSIONS: CTRX had better antimicrobial coverage than CEZ for GNR cultured from intraoperative bile samples. In addition, CTRX provides better antimicrobial prophylaxis than CEZ against superficial SSI in patients with PD after PBD. TRIAL REGISTRATION NUMBER: This study was not a clinical trial and had no registration numbers.

Surrogacy of Recurrence-free Survival for Overall Survival as an Endpoint of Clinical Trials of Perioperative Adjuvant Therapy in Hepatobiliary-pancreatic Cancers: A Retrospective Study and Meta-analysis.

OBJECTIVE: To assess the correlation between recurrence-free survival (RFS) and overall survival (OS) in the hepato-biliary-pancreatic (HBP) surgical setting in order to validate RFS as a surrogate endpoint. SUMMARY BACKGROUND DATA: Reliable surrogate endpoints for OS are still limited in the field of HBP surgery. METHODS: We analyzed patients who underwent curative resection for HBP disease (986 patients with pancreatic ductal adenocarcinoma [PDAC], 1168 with biliary tract cancer [BTC], 1043 with hepatocellular carcinoma [HCC], and 1071 with colorectal liver metastasis [CRLM]) from September 2002 to June 2022. We also conducted meta-analyses of randomized controlled trials of neoadjuvant or adjuvant therapy to validate the surrogacy in PDAC and BTC. RESULTS: Correlation coefficients between RFS and OS were low for HCC (ρ = 0.67) and CRLM (ρ = 0.53) but strong for PDAC (ρ = 0.80) and BTC (ρ = 0.75). In a landmark analysis, the concordance rates between survival or death at 5 years postoperatively and the presence or absence of recurrence at each time point (1, 2, 3, and 4 y) were 50%, 70%, 74%, and 77% for PDAC and 54%, 67%, 73%, and 78% for BTC, respectively, both increasing and reaching a plateau at 3 years. In a meta-analysis, the correlation coefficients for the RFS hazard ratio and OS hazard ratio in PDAC and BTC were ρ = 0.88 (P < 0.001) and ρ = 0.87 (P < 0.001), respectively. CONCLUSION: Three-year RFS can be a reliable surrogate endpoint for OS in clinical trials of neoadjuvant or adjuvant therapy for PDAC and BTC.

Conversion surgery for advanced jejunal adenocarcinoma with multiple peritoneal metastases: a case report.

BACKGROUND: Small bowel cancer (SBC) is a rare malignancy that is often diagnosed at an advanced stage. Palliative chemotherapy is the standard treatment for patients with metastatic SBC. The relevant literature on conversion surgery in patients who have responded favorably to chemotherapy is limited. CASE PRESENTATION: A 64-year-old man was diagnosed with jejunal carcinoma with multiple peritoneal metastases. After implanting an expandable metallic stent at the primary site, the patient underwent 6 months of FOLFOX therapy, resulting in a clinical complete response. Chemotherapy was continued, and four years after the initiation of therapy, the patient showed no evidence of disease progression. Nevertheless, anemia of continuous minor hemorrhages from the stent site and general malaise of chemotherapy got progressively worse during treatment. After confirming negative ascites cytology and the absence of peritoneal metastasis via staging laparoscopy, the patient underwent partial jejunectomy. Pathologically, no residual tumor was detected in the resected specimen. The postoperative course was uneventful, and the patient remained free of recurrence for 30 months after surgery without chemotherapy. CONCLUSION: Although infrequent, conversion surgery may be a valid therapeutic option for selected cases of SBC with peritoneal metastasis.

Liver abscess caused by Clostridium perfringens after left hepatic trisectionectomy for perihilar cholangiocarcinoma: a case report.

BACKGROUND: Clostridium perfringens sepsis has been reported to have a rapid onset and severe clinical outcome. We herein report a case of C. perfringens sepsis associated with massive intravascular hemolysis after left hepatic trisectionectomy for perihilar cholangiocarcinoma. CASE PRESENTATION: A 72-year-old woman underwent left hepatic trisectionectomy for perihilar cholangiocarcinoma. Her postoperative course was uneventful except for bile leakage. She was discharged on postoperative day (POD) 35. On POD 54, she was readmitted because of abdominal pain with a high fever. Although her vital signs were stable on arrival at the hospital, a laboratory examination showed a severe inflammatory reaction and hemolysis, and she had developed disseminated intravascular coagulation. Abdominal contrast-enhanced computed tomography showed a 70-mm irregular shape and low-density containing air in liver segment 6, which suggested a liver abscess. The abscess was immediately drained of pus containing air. The pus showed multiple Gram-positive bacilli, and two blood cultures showed Gram-positive bacilli and hemolysis. Empirical antibiotic therapy with vancomycin and meropenem was started because C. perfringens was detected from the preoperative bile culture. Four hours after arrival, tachypnea and decreased oxygen saturation were observed. Her general condition deteriorated rapidly with significant hypoglycemia, progressive acidosis, anemia, and thrombocytopenia. Despite rapid drainage and empiric therapy, she died six hours after her arrival. At autopsy, the abscess consisted of coagulation necrosis of liver cells with inflammatory cell infiltration, and clusters of Gram-positive large bacilli were observed in the necrotic debris. C. perfringens was detected in the drainage fluid and blood culture. She was diagnosed with a liver abscess and severe sepsis caused by C. perfringens and treated promptly, but the disease progressed rapidly and led to her death. CONCLUSIONS: Sepsis caused by C. perfringens can progress rapidly and lead to death in a few hours, so prompt treatment is needed. When patients who have undergone highly invasive hepatobiliary-pancreatic surgery show hemolysis and hepatic abscesses with gas, C. perfringens should be considered the most likely bacterium.

ASO Author Reflections: Prognostic Role of Preoperative Duke Pancreatic Monoclonal Antigen Type 2 Values in Patients with Pancreatic Cancer: Focusing on the Usefulness in Patients with Normal CA19-9.

Pancreatic cancer (PC) is one of the most aggressive cancer types, and carbohydrate antigen (CA) 19-9 has been the most useful biomarker for its surveillance and prognosis prediction. However, CA19-9 may not be sufficiently prognostic in some patients, such as Lewis antigen-negative phenotype (Le[a-b-]) patients who secrete little or no CA19-9. Duke pancreatic monoclonal antigen type 2 (DUPAN-2) has been proposed as a complementary marker to CA19-9 in PC patients, but its utility in Le(a-b-) patients has only been reported in a limited number of cases. In a retrospective analysis of 224 PC patients who underwent surgery, the present study investigated the utility of DUPAN-2 in combination with CA19-9. The study subjects were divided into three groups based on their CA19-9 and DUPAN-2 levels. The normal CA19-9/high DUPAN-2 group had significantly larger tumors and a higher frequency of microscopic vascular invasion, perineural invasion, and recurrence than the normal CA19-9/normal DUPAN-2 group. Both the disease-free survival and disease-specific survival (DSS) of patients in the normal CA19-9/high DUPAN-2 group were significantly shorter than those in the normal CA19-9/normal DUPAN-2 group, and comparable with those in the high CA19-9 group. The results suggest that DUPAN-2 may be useful as a complementary biomarker to CA19-9 in PC, especially in patients who have normal CA19-9 levels. However, since this was a single-center, retrospective study, multicenter studies are needed to confirm the findings and determine the optimal cut-off value for patients with normal CA19-9 levels.

Acquired hemophilia A developing in the perioperative period of pancreatoduodenectomy: a report of two cases.

BACKGROUND: Acquired hemophilia A (AHA) is a rare disease characterized by a prolonged activated partial thromboplastin time (aPTT) and the production of coagulation factor VIII inhibitors. We encountered two cases of AHA in the perioperative period of pancreatoduodenectomy (PD). CASE PRESENTATION: Case 1: A 76-year-old woman with intraductal papillary mucinous carcinoma developed acute cholecystitis 5 days before PD. Despite immediate improvement in her acute cholecystitis with biliary drainage and antibiotics, her aPTT level was prolonged (55.9 s). PD was performed as scheduled. On postoperative day (POD) 2, she developed intra-abdominal hemorrhaging that required reoperation. However, intra-abdominal bleeding and concomitant anemia persisted after reoperation. On POD 13, she was diagnosed with AHA based on the detection of an inhibitor of coagulation factor VIII. Despite hemostatic and immunosuppressive treatment, including massive blood transfusion, her general condition gradually worsened due to continuous bleeding and secondary infections. She ultimately died of multiple organ failure on POD 71. Case 2: An 82-year-old man received PD for distal cholangiocarcinoma. On POD 3, a small amount of blood via abdominal drainage was observed. On POD 4, his aPTT level was prolonged (61.5 s). On POD 8, subcutaneous hemorrhaging of the median wound was observed, and corticosteroids were administered under suspicion of AHA on POD 9. On POD 15, an inhibitor of FVIII was detected, and he was diagnosed with AHA. On POD 17, the aPTT level had normalized, and an inhibitor of FVIII was undetectable. On POD 41, he was discharged without any serious hemorrhagic events. CONCLUSIONS: AHA may be more frequent than previously reported. When unexplained prolonged aPTT or bleeding symptoms are observed, it is important to keep AHA in mind during the perioperative period of invasive surgery.

Genomic landscape of pancreatic cancer in the Japanese version of the Cancer Genome Atlas.

Background: Pancreatic cancer (PC) is one of the most aggressive cancers worldwide. Although many studies have investigated genomic alterations, the genomic landscape of Japanese PC patients has not been fully elucidated. Methods: We used whole-exome sequencing, cancer gene panel deep-sequencing, and microarray gene expression profiling data derived from the Japanese version of the Cancer Genome Atlas (JCGA) in 93 PC cases. Results: Somatic driver mutations were identified in 65.6% of samples in 19 genes. The median tumor mutation burden (TMB) value was 0.24 Muts/Mb (interquartile range, 0.15-0.64 Muts/Mb). The commonly mutated genes were KRAS (58%), TP53 (40%), CDKN2A (10%), SMAD4 (10%), FGFR2 (9%), and PKHD1 (9%). Frequent germline variation genes were BRCA1 (8%), CDH1 (5%), MET (5%), MSH6 (5%), and TEK (5%). Frequent chromosomal arm alterations included copy number gains in 2q (42%), 7q (24%), and 3q (24%), and copy number losses in 19p (62%), 19q (47%), 12q (34%), and 7q (30%). A prognostic analysis according to the presence of driver mutations showed that overall survival (OS) in the driver mutation-positive group was significantly worse in comparison to that of the driver mutation-negative group (median, 23.1 vs 46.7 mo; P = .010). A Cox proportional hazards analysis for OS identified driver mutation (hazard ratio [HR], 1.89; P = .025) and lymph node metastasis (HR, 3.27; P = .002) as independent prognostic factors. Conclusion: The present results from the JCGA dataset constitute a fundamental resource for genomic medicine for PC patients, especially in Japan.

The authors reply: Re: Yamamoto R, Sugiura T, Ashida R, Ohgi K, Yamada M, Otsuka S, and Uesaka K. Prognostic value of carbohydrate antigen 19-9 and the surgical margin in extrahepatic Cholangiocarcinoma. Ann Gastroenterol Surg. 2022;6:307-315.

The specific growth rate of the perioperative carbohydrate antigen 19-9 values was not related to the prognosis of extrahepatic cholangiocarcinoma.

Prognostic Role of Preoperative Duke Pancreatic Monoclonal Antigen Type 2 Levels in Patients with Pancreatic Cancer.

BACKGROUND: This study aimed to evaluate the clinical implication of Duke pancreatic monoclonal antigen type 2 (DUPAN-2) for patients with pancreatic cancer (PC), especially those with normal carbohydrate antigen (CA) 19-9 levels. METHODS: The study reviewed 224 patients who underwent surgery for PC from January 2003 through December 2019 at the Shizuoka Cancer Center. The patients were divided into three groups according to the following CA19-9 and DUPAN-2 levels: normal CA19-9/normal DUPAN-2, normal CA19-9/high DUPAN-2, and high CA19-9. The prognostic utility of the DUPAN-2 levels in the normal CA19-9 patients was investigated. RESULTS: Elevated serum levels of DUPAN-2 were observed in 29 (25.2%) of the normal CA19-9 patients. The cutoff value for serum DUPAN-2 level was set at 250 U/ml. Both disease-free survival and disease-specific survival (DSS) in the normal CA19-9/high DUPAN-2 group were significantly shorter than in the normal CA19-9/normal DUPAN-2 group and comparable with those in the high CA19-9 group. In the normal CA19-9 group, DUPAN-2 was identified as an independent prognostic factor for DSS. The patients with normal CA19-9/high DUPAN-2 had higher pathologic malignancy than the patients with normal CA19-9/normal DUPAN-2, which was comparable with that in the patients with high CA19-9. CONCLUSION: In PC, DUPAN-2 may be useful as a biomarker complementary with CA19-9. The combination of these two markers may aid in the preoperative prediction of prognosis for patients with PC.

Long-term adjuvant chemotherapy after resection for pancreatic cancer patients with positive peritoneal lavage cytology.

PURPOSE: The significance of resection for pancreatic cancer with positive peritoneal lavage cytology (CY +) remains controversial, and the lack of evidence concerning adjuvant chemotherapy (AC) in these patients remains an issue. The aim of the present study was to investigate the prognostic impacts of AC and its duration on the survival outcome in patients with CY + pancreatic cancer. METHODS: A total of 482 patients with pancreatic cancer who underwent pancreatectomy between 2006 and 2017 were retrospectively analyzed. The overall survival (OS) was compared among the patients with CY + tumors according to the duration of AC. RESULTS: Among the resected patients, 37 (7.7%) had CY + tumors: 13 received AC for > 6 months, 15 received AC for ≤ 6 months and 9 did not receive AC. The OS of 13 patients with resected CY + tumors who received AC for > 6 months was comparable to that of 445 patients with resected CY- tumors (median survival time 43.0 vs. 33.6 months, P = 0.791), and was significantly better than that of 15 patients with resected CY + tumors who received AC for ≤ 6 months (vs. 16.6 months, P = 0.017). The duration of AC (> 6 months) was an independent prognostic factor in patients with resected CY + tumors (hazard ratio 3.29, P = 0.005). CONCLUSION: Long-term AC (> 6 months) may improve postoperative survival in pancreatic cancer patients with CY + tumors.

Impact of obstructive ventilatory impairment on intraoperative bleeding during laparoscopic hepatectomy.

PURPOSE: An animal model of laparoscopic hepatectomy showed that bleeding from the hepatic vein is influenced by airway pressure. However, there are little research reports on how airway pressure leads to risks in clinical practice. The main objective of this study was to investigate the impact of preoperative forced expiratory volume % in 1 s (FEV1.0%) on intraoperative blood loss in laparoscopic hepatectomy. METHODS: All patients who underwent pure laparoscopic or open hepatectomy from April 2011 to July 2020 were classified into two groups by preoperative spirometry: those with obstructive ventilatory impairment (obstructive group; FEV1.0% < 70%) and those with normal respiratory function (ormal group; FEV1.0% ≥ 70%). Massive blood loss was defined as 400 mL for laparoscopic hepatectomy. RESULTS: In total, 247 and 445 patients underwent pure laparoscopic and open hepatectomy, respectively. Regarding laparoscopic hepatectomy group, blood loss was significantly greater in the obstructive group (122 vs. 100 mL, P = 0.042). Multivariate analysis revealed that high IWATE criteria which classify the surgical difficulty of laparoscopic hepatectomy (≥ 7, odds ratio (OR): 4.50, P = 0.004) and low preoperative FEV1.0% (< 70%, OR: 2.28, P = 0.043) were independent risk factors for blood loss during laparoscopic hepatectomy. In contrast, FEV1.0% did not affect the blood loss (522 vs. 605 mL, P = 0.113) during open hepatectomy. CONCLUSION: Obstructive ventilatory impairment (low FEV1.0%) may affect the amount of bleeding during laparoscopic hepatectomy.

Characterization of pancreatic cancer with ultra-low tumor mutational burden.

In pancreatic cancer (PC), Tumor mutation burden (TMB) has been reported to be lower than in other cancers, with its clinical significance remaining unclear. We analyzed the dataset of whole-exome sequencing and gene expression profiling of 93 resected PC cases. The median TMB was 0.24. The TMB was classified as High (≥ 5.0), Low (< 5.0, ≥ 1.0), or Ultra-low (< 1.0). Nineteen samples (20%) were classified as TMB-low, and 74 (80%) were classified as TMB-ultra-low; no samples were TMB-high. TMB-ultra-low PC had significantly fewer borderline resectable lesions (P = 0.028) and fewer adenosquamous carcinomas (P = 0.003) than TBM-low PC. Furthermore, the TMB-ultra-low PC showed significantly lower detection rates of driver mutations and copy number variations. Microsatellite instability was not significantly correlated with the TMB status. The TMB-ultra-low PC had a significantly better prognosis than TBM-low PC (P = 0.023). A multivariate analysis identified TMB-ultra-low PC as an independent favorable prognostic factor (hazard ratio, 2.11; P = 0.019). A gene expression analysis showed that TMB-ultra-low PC was associated with reduced TP53 inactivation (P = 0.003) and reduced chromosomal instability (P = 0.001) compared to TBM-low PC. TMB-ultra-low PC had specific gene expression signatures and a better prognosis than TMB-low PC.