Prognostic Relevance of Primary Tumor Sidedness in Early-stage Colorectal Cancer: An Integrated Analysis of 4 Randomized Controlled Trials (JCOG2003A).

OBJECTIVE: The aim of this study was to determine the genuine prognostic relevance of primary tumor sidedness (PTS) in patients with early-stage colorectal cancer (CRC). BACKGROUND: The prognostic relevance of PTS in early-stage CRC remains a topic of debate. Several large epidemiological studies investigated survival only and did not consider the risk of recurrence so far. METHODS: Patients with stage II/III adenocarcinoma of the colon and upper rectum from 4 randomized controlled trials were analyzed. Survival outcomes were compared according to the tumor location: right-sided (cecum to transverse colon) or left-sided (descending colon to upper rectum). RESULTS: A total of 4113 patients were divided into a right-sided group (N=1349) and a left-sided group (N=2764). Relapse-free survival after primary surgery was not associated with PTS in all patients and each stage [hazard ratio (HR) adjusted =1.024 (95% CI: 0.886-1.183) in all patients; 1.327 (0.852-2.067) in stage II; and 0.990 (0.850-1.154) in stage III]. Also, overall survival after primary surgery was not associated with PTS in all patients and each stage [HR adjusted =0.879 (95% CI: 0.726-1.064) in all patients; 1.517 (0.738-3.115) in stage II; and 0.840 (0.689-1.024) in stage III]. In total, 795 patients (right-sided, N=257; left-sided, N=538) developed recurrence after primary surgery. PTS was significantly associated with overall survival after recurrence (HR adjusted =0.773, 95% CI: 0.627-0.954). CONCLUSIONS: PTS had no impact on the risk of recurrence for stage II/III CRC. Treatment stratification based on PTS is unnecessary for early-stage CRC.

Defining Benchmarks for Pelvic Exenteration Surgery: A Multicentre Analysis of Patients with Locally Advanced and Recurrent Rectal Cancer.

OBJECTIVE: To establish globally applicable benchmark outcomes for pelvic exenteration (PE) in patients with locally advanced primary (LARC) and recurrent rectal cancer (LRRC), using outcomes achieved at highly specialised centres. BACKGROUND DATA: PE is established as the standard of care for selected patients with LARC and LRRC. There are currently no available benchmarks against which surgical performance in PE can be compared for audit and quality improvement. METHODS: This international multicentre retrospective cohort study included patients undergoing PE for LARC or LRRC at 16 highly experienced centres between 2018 and 2023. Ten outcome benchmarks were established in a lower-risk subgroup. Benchmarks were defined by the 75th percentile of the results achieved at the individual centres. RESULTS: 763 patients underwent PE, of which 464 patients (61%) had LARC and 299 (39%) had LRRC. 544 patients (71%) who met predefined lower risk criteria formed the benchmark cohort. For LARC patients, the calculated benchmark threshold for major complication rate was ≤44%; comprehensive complication index (CCI): ≤30.2; 30-day mortality rate: 0%; 90-day mortality rate: ≤4.3%; R0 resection rate: ≥79%. For LRRC patients, the calculated benchmark threshold for major complication rate was ≤53%; CCI: ≤34.1; 30-day mortality rate: 0%; 90-day mortality rate: ≤6%; R0 resection rate: ≥77%. CONCLUSIONS: The reported benchmarks for PE in patients with LARC and LRRC represent the best available care for this patient group globally and can be used for rigorous assessment of surgical quality and to facilitate quality improvement initiatives at international exenteration centres.

Long-Term Outcomes of Additional Surgery After Endoscopic Resection Versus Primary Surgery for T1 Colorectal Cancer.

INTRODUCTION: There is considerable concern about whether endoscopic resection (ER) before additional surgery (AS) for T1 colorectal cancer (CRC) has oncologically potential adverse effects. Therefore, the aim of this study was to compare the long-term outcomes, including overall survival (OS), of patients treated with AS after ER vs primary surgery (PS) for T1 CRC using a propensity score-matched analysis from a large observational study. METHODS: This study investigated 6,105 patients with T1 CRC treated with either ER or surgical resection between 2009 and 2016 at 27 high-volume Japanese institutions, with those undergoing surgery alone included in the PS group and those undergoing AS after ER included in the AS group. Propensity score matching was used for long-term outcomes of mortality and recurrence analysis. RESULTS: After propensity score matching, 1,219 of 2,438 patients were identified in each group. The 5-year OS rates in the AS and PS groups were 97.1% and 96.0%, respectively (hazard ratio: 0.72, 95% confidence interval: 0.49-1.08), indicating the noninferiority of the AS group. Moreover, 32 patients (2.6%) in the AS group and 24 (2.0%) in the PS group had recurrences, with no significant difference between the 2 groups (odds ratio: 1.34, 95% confidence interval: 0.76-2.40, P = 0.344). DISCUSSION: ER before AS for T1 CRC had no adverse effect on patients' long-term outcomes, including the 5-year OS rate. ER is a viable first-line treatment option for endoscopically resectable T1 CRC.

Treatment Decision for Locally Resected T1 Colorectal Carcinoma-Verification of the Japanese Guideline Criteria for Additional Surgery Based on Long-Term Clinical Outcomes.

INTRODUCTION: To verify the value of the pathological criteria for additional treatment in locally resected pT1 colorectal carcinoma (CRC) which have been used in the Japanese Society for Cancer of the Colon and Rectum (JSCCR) guidelines since 2009. METHODS: We enrolled 4,667 patients with pT1 CRC treated at 27 institutions between July 2009 and December 2016 (1,257 patients with local resection alone [group A], 1,512 patients with additional surgery after local resection [group B], and 1,898 patients with surgery alone [group C]). All 5 factors of the JSCCR guidelines (submucosal resection margin, tumor histologic grade, submucosal invasion depth, lymphovascular invasion, and tumor budding) for lymph node metastasis (LNM) had been diagnosed prospectively. RESULTS: Any of the risk factors were present in 3,751 patients. The LNM incidence was 10.4% (95% confidence interval 9.4-11.5) in group B/C patients with risk factors, whereas it was 1.8% (95% confidence interval 0.4-5.3) in those without risk factors ( P < 0.01). In group A, the incidence of recurrence was 3.6% in patients with risk factors, but it was only 0.4% in patients without risk factors ( P < 0.01). The disease-free survival rate of group A patients classified as risk positive was significantly worse than those of groups B and C patients. However, the 5-year disease-free survival rate in group A patients with no risk was 99.6%. DISCUSSION: Our large-scale real-world multicenter study demonstrated the validity of the JSCCR criteria for pT1 CRC after local resection, especially regarding favorable outcomes in patients with low risk of LNM.

Long-term Outcome After Surgical Resection of Paraaortic Lymph Node Metastasis of Colorectal Cancer: A Multicenter Retrospective Study.

BACKGROUND: The significance of resection of paraaortic lymph node metastasis in colorectal cancer is controversial. OBJECTIVE: To clarify the prognosis of colorectal cancer after paraaortic lymph node metastasis resection. DESIGN: Multicenter retrospective study. SETTINGS: Thirty-six institutions in Japan participated in this study. PATIENTS: Patients with resected and pathologically proven paraaortic lymph node metastasis of CRC between 2010 and 2015. DATA SOURCES: Database and medical records at each institution. MAIN OUTCOME MEASURES: Overall survival after paraaortic lymph node metastasis resection, recurrence-free survival, and recurrence patterns after R0 resection of paraaortic lymph node metastasis. RESULTS: A total of 133 patients were included in the primary analysis population in this study. The 5-year overall survival rate (95% confidence interval [CI]) was 41.0% (32.0, 49.8), and the median survival (95% CI) was 4.1 (3.4, 4.7) years. Independent prognostic factors for overall survival were the pathological T stage (pT4 vs. pT1- 3, adjusted hazard ratio [aHR]: 1.91, p = 0.006), other organ metastasis (present vs. absent, aHR: 1.98, p = 0.005), time to metastases (synchronous vs. metachronous, aHR: 2.02, p = 0.02), and number of paraaortic lymph node metastasis (≥3 vs. <3, aHR: 2.13, p = 0.001). The 5-year recurrence-free survival rate (95% CI) was 21.1% (13.5, 29.7), with a median (95% CI) of 1.2 (0.9, 1.4) years. The primary tumor location (left- vs. right-sided colon, aHR: 4.77, p = 0.01; rectum vs. right-sided colon, aHR: 5.27, p = 0.006), other organ metastasis (present vs. absent, aHR: 1.90, p = 0.03), number of paraaortic lymph node metastasis (≥3 vs. <3, aHR: 2.20, p = 0.001), and hospital volume (<10 vs. ≥10, aHR: 2.18, p = 0.02) were identified as independent prognostic factors for recurrence-free survival. Paraaortic lymph node recurrence was the most common at 33.3%. LIMITATIONS: Selection bias cannot be ruled out because of the retrospective nature of the study. CONCLUSIONS: Less than three paraaortic lymph node metastasis was a favorable prognostic factor for both overall survival and recurrence-free survival. However, paraaortic lymph node metastases were considered to be a systemic disease and the significance of resection was limited. See Video Abstract.

Prognostic impact of primary tumour location after curative resection in Stage I-III colorectal cancer: a single-centre retrospective study.

OBJECTIVE: The relationship of tumour site with post-recurrence course and outcome after primary surgery in resectable colorectal cancer is unclear. This study investigated the prognostic impact of primary tumour location following radical resection without preoperative treatment in Stage I-III colorectal cancer. METHODS: We analyzed 3770 patients with Stage I-III colorectal cancer who underwent curative resection at our hospital during 2000-15. We defined the right-sided colon as the cecum, ascending colon and transverse colon, and the left-sided colon as the descending colon, sigmoid and rectosigmoid junction. Patients were divided into three groups according to tumour site: right-sided colon, left-sided colon and rectum. Endpoints were overall survival, recurrence-free survival by stage and survival after recurrence, respectively. RESULTS: The 5-year overall survival rates of patients with stage I left-sided colon cancer, right-sided colon cancer and rectal cancer were 98.2, 97.3 and 97.2%, respectively (P = 0.488). The 5-year overall survival rates of patients with Stage II left-sided colon cancer, right-sided colon cancer and rectal cancer were 96.2, 88.7 and 83.0, respectively (P = 0.070). The 5-year overall survival rates of patients with Stage III left-sided colon cancer, right-sided colon cancer and rectal cancer were 88.7, 83.0 and 80.2, respectively (P = 0.001). The 5-year recurrence-free survival rates of patients with Stage I left-sided colon cancer, right-sided colon cancer and rectal cancer were 95.1, 94.5 and 90.6% (P = 0.027). The 5-year recurrence-free survival rates of patients with Stage II left-sided colon cancer, right-sided colon cancer and rectal cancer were 85.2, 90.2 and 76.1%, respectively (P < 0.001). The 5-year recurrence-free survival rates of patients with Stage III left-sided colon cancer, right-sided colon cancer and rectal cancer were 75.3, 75.3 and 59.8%, respectively (P < 0.001). Right-sided colon cancer was significantly associated with better recurrence-free survival compared with left-sided colon cancer (HR 1.29, 95% CI 1.03-1.63; P = 0.025) and rectal cancer (HR 1.89, 95% CI 1.51-2.38; P < 0.001) after adjusting for clinical factors. Amongst patients with recurrence, right-sided colon cancer was significantly associated with poorer survival after recurrence compared with left-sided colon cancer (HR 0.68, 95% CI 0.48-0.97; P = 0.036), and showed a tendency towards poorer survival after recurrence compared with rectal cancer (HR 0.79, 95% CI 0.57-1.10; P = 0.164). CONCLUSIONS: In Stage I-III colorectal cancer without preoperative treatment, our results suggest that the three tumour sites (right-sided colon, left-sided colon or rectum) may have prognostic significance for recurrence-free survival and survival after recurrence, rather than sidedness alone.

Cost-effectiveness of surveillance intervals after curative resection of colorectal cancer.

BACKGROUND: Major guidelines consistently recommend 5 years of postoperative surveillance for patients with colorectal cancer. However, they differ in their recommendations for examination intervals and whether they should vary according to disease stage. Furthermore, there are no reports on the cost-effectiveness of the different surveillance schedules. The objective of this study is to identify the most cost-effective surveillance intervals after curative resection of colorectal cancer. METHODS: A total of 3701 patients who underwent curative surgery for colorectal cancer at the National Cancer Center Hospital were included. A cost-effectiveness analysis was conducted for the five surveillance strategies with reference to the guidelines. Expected medical costs and quality-adjusted life years after colorectal cancer resection were calculated using a state-transition model by Monte Carlo simulation. The incremental cost-effectiveness ratio per quality-adjusted life years gained was calculated for each strategy, with a maximum acceptable value of 43 500-52 200 USD (5-6 million JPY). RESULTS: Stages I, II and III included 1316, 1082 and 1303 patients, respectively, with 45, 140 and 338 relapsed cases. For patients with stage I disease, strategy 4 (incremental cost-effectiveness ratio $26 555/quality-adjusted life year) was considered to be the most cost-effective, while strategies 3 ($83 071/quality-adjusted life year) and 2 ($289 642/quality-adjusted life year) exceeded the threshold value. In stages II and III, the incremental cost-effectiveness ratio for strategy 3 was the most cost-effective option, with an incremental cost-effectiveness ratio of $18 358-22 230/quality-adjusted life year. CONCLUSIONS: In stage I, the cost-effectiveness of intensive surveillance is very poor and strategy 4 is the most cost-effective. Strategy 3 is the most cost-effective in stages II and III.

Real-world treatment costs of first-line treatment for metastatic colorectal cancer: a survey of the JCOG colorectal cancer study group.

BACKGROUND: Although treatment outcomes for metastatic colorectal cancer (mCRC) have dramatically improved over the past few decades, drug costs have also significantly increased. This study aimed to investigate which first-line treatment regimens for mCRC are actually used (frequency) in Japanese practice and at what cost. METHODS: We collected data on patients with mCRC who received first-line treatment at 37 institutions of the Japan Clinical Oncology Group Colorectal Cancer Study Group from July 2021 to June 2022, and calculated the cost of regimens. The cost per month of each regimen was estimated based on standard usage, assuming a patient with a weight of 70 kg and a body surface area of 1.8 m2. We categorized the regimens into very high-cost (≥1 000 000 Japanese yen [JPY]/month), high-cost (≥500 000 JPY/month), and others (<500 000 JPY/month). RESULTS: The study included 1880 participants, 24% of whom were ≥ 75 years. Molecular targeted containing regimens were received by 78% of the patients. The most frequently used regimen was the doublet regimen (fluoropyrimidine with either oxaliplatin or irinotecan) plus bevacizumab (43%), followed by doublet plus cetuximab or panitumumab (21%). The cost of molecular targeted drugs-containing regimens (ranging from 85 406 to 843 602 JPY/month) is much higher than that of only cytotoxic drug regimens (ranging from 17 672 to 51 004 JPY/month). About 16% received high-cost treatments that included panitumumab-containing regimens and pembrolizumab (17% of patients aged ≤74 years and 11% of patients aged ≥75 years). CONCLUSION: About 16% of mCRC patients received first-line treatment with regimens costing >500 000JPY/month, and molecular targeted drugs being the main drivers of cost.

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.

Clinical utility of sarcopenia dynamics assessed by psoas muscle volume in patients with colorectal cancer.

BACKGROUND: Sarcopenia affects the postoperative prognosis of patients with colorectal cancer (CRC). Recently, it has become possible to measure psoas volume from computed tomography images, and an index called psoas volume index (PVI) has been reported. However, it is unclear whether the dynamics of PVI before and after surgery is associated with clinical outcomes after CRC surgery. This study aimed to evaluate the association between pre- and postoperative PVI dynamics and clinical outcomes after CRC surgery. METHODS: This study analyzed 1115 patients diagnosed with primary CRC and operated on for treatment between January 2014 and December 2017. Sarcopenia was defined as PVI below the lowest tertile in the preoperative assessment for each sex. The overall population was divided into four groups according to the dynamics of sarcopenia from preoperative to postoperative: group 1 (pre-to postoperative sarcopenia), group 2 (preoperative nonsarcopenia to postoperative sarcopenia), group 3 (pre-to postoperative nonsarcopenia), and group 4 (pre-to postoperative nonsarcopenia). RESULTS: Based on pre- and postoperative sarcopenia dynamics, 343 patients (29.7%) were classified into group 1, 105 patients (9.1%) into group 2, 42 patients (3.6%) into group 3, and 665 patients (57.6%) into group 4. Comparison of overall survival (OS) by the Kaplan-Meier method showed that Group 2 tended to have the worst prognosis (p = 0.007). Multivariate analysis showed an increased OS risk in Group 2 in sarcopenia dynamics (Hazard ratio: 2.103, 95% CI: 1.202-3.681, p = 0.009). CONCLUSIONS: Sarcopenia dynamics using PVI is an independent prognostic predictor of OS in patients with CRC.