Application of targeted nanopore sequencing for the screening and determination of structural variants in patients with Lynch syndrome.

Lynch syndrome is a hereditary disease characterized by an increased risk of colorectal and other cancers. Germline variants in the mismatch repair (MMR) genes are responsible for this disease. Previously, we screened the MMR genes in colorectal cancer patients who fulfilled modified Amsterdam II criteria, and multiplex ligation-dependent probe amplification (MPLA) identified 11 structural variants (SVs) of MLH1 and MSH2 in 17 patients. In this study, we have tested the efficacy of long read-sequencing coupled with target enrichment for the determination of SVs and their breakpoints. DNA was captured by array probes designed to hybridize with target regions including four MMR genes and then sequenced using MinION, a nanopore sequencing platform. Approximately, 1000-fold coverage was obtained in the target regions compared with other regions. Application of this system to four test cases among the 17 patients correctly mapped the breakpoints. In addition, we newly found a deletion across an 84 kb region of MSH2 in a case without the pathogenic single nucleotide variants. These data suggest that long read-sequencing combined with hybridization-based enrichment is an efficient method to identify both SVs and their breakpoints. This strategy might replace MLPA for the screening of SVs in hereditary diseases.

Correction: Importance of gastric cancer for the diagnosis and surveillance of Japanese Lynch syndrome patients.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Long-term clinical outcomes and follow-up status in Japanese patients with familial adenomatous polyposis after radical surgery: a descriptive, retrospective cohort study from a single institute.

PURPOSE: Data on long-term outcomes of familial adenomatous polyposis (FAP) are unclear in Japan because a nationwide registry system is lacking. We assessed overall survival, incidence of neoplasms, fecal incontinence, and postoperative follow-up status of patients with FAP treated surgically in our hospital. METHODS: In total, 154 patients with FAP who underwent radical surgery from 1981 to 2017 in our department were available for the questionnaire. Sixty-five patients, 36 of whom were followed at our hospital, were assessed using clinical records and the questionnaire. RESULTS: The median follow-up time was 187 months (interquartile range, 93.5-296 months). The median age at surgery was 36 years (range, 12-69 years). The 5-, 10-, 15-, and 20-year overall survival rate was 100%, 98%, 95%, and 89%, respectively. All five deaths were caused by diseases other than colorectal cancer. FAP-related neoplasms comprised 23 colorectal cancers, five duodenal cancers, three gastric cancers, five thyroid cancers, two ileal pouch cancers, and nine desmoid tumors. The incidence of desmoid tumors was significantly associated with the operation date. The duration from radical surgery to neoplasm onset significantly differed by neoplasm type. Forty-five of 54 patients (excluding those who died or underwent ileostomy) developed fecal incontinence (median Wexner score of 8). Surgical procedures involving hand-sewn sutures with rectal mucosal stripping were significantly associated with fecal incontinence and the Wexner score. Fifty-eight of the 60 surviving patients underwent follow-up examinations. CONCLUSION: Overall survival was favorable. Fecal incontinence depended on the surgical procedures. Most patients continued to receive follow-up examinations. TRIAL REGISTRATION: No. 3112 by Institutional Review Board of Hyogo College of Medicine.

Importance of gastric cancer for the diagnosis and surveillance of Japanese Lynch syndrome patients.

Lynch syndrome (LS) is an autosomal dominantly inherited disease predisposed to not only colorectal cancer but also other LS-related tumors. Although the clinical and genetic characteristics of LS in Western countries have been well characterized, the information of Japanese LS is limited. As a collaborative study of Japanese Society for Cancer of the Colon and Rectum (JSCCR), we registered colorectal cancer (CRC) patients who fulfilled the modified Amsterdam II criteria including gastric cancer as an LS-related tumor. Among 4030 CRC patients initially registered in this project, 85 patients (2.1%) fulfilled the modified criteria. An additional 26 patients who met the same criteria were enrolled in the analysis. We analyzed three major responsible genes, MLH1, MSH2, and MSH6 by direct sequencing, and further performed multiplex ligation-dependent probe amplification for MLH1 and MSH2. Consequently, we identified pathogenic variants in 64 of the 111 patients comprising of 34 patients in MLH1, 28 in MSH2, and 2 in MSH6. It is of note that large structural alterations were found in 17 patients. Among the 64 patients, 11 patients would not have been enrolled in the analysis if gastric cancer were not included in the modified criteria. In addition, 10 of the 64 variant carriers (15.6%) had medical history of gastric cancer. Furthermore, the standardized incidence ratio of gastric cancer in the LS patients to the Japanese population is estimated to be as high as 20.2. These data underscore the importance of gastric cancer in the diagnosis and healthcare of Japanese LS patients.

Prevalence of and risk factors for thyroid carcinoma in patients with familial adenomatous polyposis: results of a multicenter study in Japan and a systematic review.

PURPOSE: To investigate the recent Japanese prevalence of thyroid cancer and its characteristics in familial adenomatous polyposis (FAP) patients, through the development of surveillance programs. METHODS: The subjects of this study were 282 (93.1%) FAP patients for whom information on thyroid cancer was available, from among 303 patients registered in "the Retrospective Cohort Study of Familial Adenomatous Polyposis in Japan" database. We evaluated the prevalence and risk factors for thyroid cancer and integrated and/or compared our findings with those of previous reports, using a systematic review, including a meta-analysis. RESULTS: Thyroid cancer was diagnosed in 16 women (11.4%) and 2 men (1.4%), at 17-41 years and 39-57 years of age, respectively. The prevalence of thyroid cancer was 6.4%, with a female-to-male ratio of 8:1, which is comparable to reports from other countries. A young age of < 33 years at the FAP diagnosis and female gender were identified as independent risk factors for thyroid cancer. CONCLUSIONS: FAP-associated thyroid cancer predominantly affects young women, both in Japan and other countries. Since FAP is generally diagnosed when patients are in their 20 s or older, regular screening for thyroid cancer is recommended for all FAP patients, but especially women, from their early 20 s.

Alcohol consumption and early-onset risk of colorectal cancer in Japanese patients with Lynch syndrome: a cross-sectional study conducted by the Japanese Society for Cancer of the Colon and Rectum.

We conducted this study to establish whether drinking alcohol alters the risk of early-onset colorectal cancer (CRC) in Japanese patients with Lynch syndrome (LS). The subjects were 66 LS patients with pathogenic mutation of mismatch repair genes (MLH1, MSH2, and MSH6) from the nationwide Japanese retrospective multicenter study. Cox proportional hazards modeling was used to investigate the factors correlating with early-onset CRC diagnosis, using clinical data such as gender, tobacco use, alcohol consumption, body mass index, gene mutation (MLH1, MSH2 vs MSH6), and family cancer history. Alcohol was significantly correlated with an increased risk of early-onset CRC [HR 2.44, 95% CI 1.13-5.16 (p = 0.02)], but tobacco use was not [HR 0.8, 95%CI 0.38-1.62 (p = 0.53)]. These findings suggest that alcohol consumption is correlated with an earlier onset of CRC in Japanese patients with LS.

[A Case of Locally Advanced Sigmoid Colon Cancer Occupying the Pelvis with Successful Total Posterior Pelvic Exenteration after Triplet Chemotherapy].

We report a case of locally advanced colon cancer that directly invaded the rectum wall and uterus resulting in huge mass in the whole pelvis that we could successfully made complete radical resection of the whole tumor without exposing the tumor to the surgical margin after the triplet chemotherapy. The patient was a 57-year-old woman complaining of anus pain, melena, fever, and weight loss. Although swelling of the regional lymph node was observed, no distant metastasis was found resulting in clinical diagnosis of Stage Ⅲb. However, oncologically safe complete resection seemed difficult; thus, chemotherapy( 3 courses of FOLFOX followed by 3 courses of FOLFOXIRI plus bevacizumab)was administered. As a result, significant tumor reduction was observed; therefore, the tumor was completely resected with posterior pelvic exenteration. Final staging was ypT4bypN0M0(ypStage Ⅱ). Eight courses of CapeOX was administered as adjuvant chemotherapy.

Management strategies in Lynch syndrome and familial adenomatous polyposis: a national healthcare survey in Japan.

Lynch syndrome (LS) and familial adenomatous polyposis (FAP) are major sources of hereditary colorectal cancer (CRC) and are associated with other malignancies. There is some heterogeneity in management strategies in Japan. We undertook a survey of management of hereditary CRC in hospitals that are members of the Japan Society of Colorectal Cancer Research. One hundred and ninety departments responded, of which 127 were from designated cancer care hospitals (DCCHs) according to the Japanese government. There were 25 488 operations for CRC in these departments in 2015. The DCCHs performed better with regard to usage of Japan Society of Colorectal Cancer Research guidelines, referring new CRC patients for LS screening, and having in-house genetic counselors and knowledge of treatment for LS. There were 174 patients diagnosed with LS and 602 undergoing follow-up in 2011-2015, which is fewer than the number expected from CRC operations in 2015. These numbers were not affected by whether the institution was a DCCH. Universal screening for LS was carried out in 8% of the departments. In contrast, 541 patients were diagnosed with FAP and 273 received preventive proctocolectomy/colectomy in 2011-2015. The DCCH departments undertook more surgery than non-DCCH departments, although most of the management, including surgical procedures and use of non-steroidal anti-inflammatory drugs, was similar. Management of desmoid tumor in the abdominal cavity differed according to the number of patients treated. In conclusion, there was heterogeneity in management of LS but not FAP. Most patients with LS may be overlooked and universal screening for LS is not common in Japan.

Human RAD 17 Polymorphism at Codon 546 Is Associated with the Risk of Colorectal Cancer.

Human RAD17 acts as an activator of checkpoint signals in response to DNA damage. Here we evaluated the association of hRAD17 Leu546Arg (rs1045051), a missense single nucleotide polymorphism, with the risk of colorectal cancer (CRC) in relation to smoking and alcohol consumption habits in 212 CRC patients and 1,142 cancer-free controls in a case-control study conducted in Japan. The results showed that the hRAD17 Leu/Arg genotype compared to the Leu/Leu genotypes was significantly associated with the protective effect on CRC risk with the adjusted odds ratio (OR) of 0.68 [95% confidence interval (CI): 0.49-0.95, p=0.024], and the males with the Arg/Arg genotype had a greater risk of CRC compared to those with the Leu/Leu and Leu/Arg genotypes (OR=1.87, 95%CI 1.03-3.40, p=0.04). In stratified studies, the protective effect of the Leu/Arg genotype on CRC risk was markedly higher in the light smokers (< 20 pack years) (OR=0.61, 95%CI 0.40-0.94, p=0.024) and the rectal cancer patients (OR=0.49, 95%CI 0.31-0.78, p=0.003). The risk of the Arg/Arg genotype was associated with heavy smoking (≥ 20 pack-years) (OR=2.24, 95%CI 1.09-4.61, p=0.03). These findings suggest that the genetic variant of hRAD17 Leu546Arg polymorphism has a significant effect on CRC susceptibility in Japanese.

Childbirth after surgery for familial adenomatous polyposis in Japan.

PURPOSE: Familial adenomatous polyposis (FAP) is a genetic disorder. Some female patients with FAP can become pregnant. However, the current state of childbirth after surgery for FAP is unclear in Japan. METHODS: The study investigated 303 patients (147 female) who had undergone surgery for FAP at the 23 institutions between 2000 and 2012. RESULTS: Eighty female patients had information available on childbirth after surgery for FAP. Eight patients (10 %) gave birth after surgery. The mean age at surgery for FAP was 27 (range 20-41) years and 37 years in patients with and without childbirth after surgery, respectively (P = 0.044). The rate of childbirth after surgery was 17 % in women ≤30 years of age and 13 % in those ≤40 years of age. Although only one patient with invasive cancer (2.9 %) gave childbirth after surgery, seven patients without cancer (15.6 %) gave birth (P = 0.045). CONCLUSIONS: This study clarified the current state of childbirth after surgery for FAP in Japan. It is important to use these data to determine the best therapeutic approach for female FAP patients.

Association between the age and the development of colorectal cancer in patients with familial adenomatous polyposis: a multi-institutional study.

PURPOSE: To investigate the incidence of colorectal cancer among familial adenomatous polyposis (FAP) patients by phenotype using the latest modalities. METHODS: We collected data on 303 patients who underwent surgery for FAP at one of 23 institutions between 2000 and 2012. The incidence of colorectal cancer was investigated by phenotype. RESULTS: Colorectal cancer was diagnosed in 115 (38.0 %) of the 303 patients. Overall, colorectal cancer with the attenuated, sparse, and profuse phenotypes was diagnosed at 30, 31, and 28 years of age, respectively, in 10 % of the patients and at 59, 48, and 41 years of age, respectively, in 50 % of the patients (P = 0.013). The patients with colorectal cancer were older than those without colorectal cancer for all phenotypes. The optimal cut-off age for predicting the development of colorectal cancer in the attenuated, sparse, and profuse phenotypes was 46, 31, and 27 years, respectively. CONCLUSIONS: Patients with profuse and sparse phenotypes should undergo prophylactic proctocolectomy before their mid-to-late 20 s. On the other hand, the timing and type of surgery for patients with attenuated FAP (AFAP) should be decided individually with reference to the colonoscopic findings.

The treatment of desmoid tumors associated with familial adenomatous polyposis: the results of a Japanese multicenter observational study.

PURPOSE: Familial adenomatous polyposis (FAP)-associated desmoid tumor (DT) is sometimes life threatening. However, the optimal treatment for DTs has not been established. The aim of this study was to analyze the outcomes of surgical and pharmacological treatments for DT in Japanese FAP patients. METHODS: We retrospectively reviewed the data of 303 patients who underwent colectomy for FAP between 2000 and 2012. We analyzed 41 patients with DTs in which the location was apparent. The selection of treatment for intra-abdominal DTs was also evaluated according to Church's classification. RESULTS: Surgery was frequently used to treat extra-abdominal DTs. Multimodal treatments, including surgery, and the administration of non-steroidal anti-inflammatory drugs, hormonal therapy, and chemotherapy were widely used for intra-abdominal DTs. The most effective pharmacological treatment was cytotoxic chemotherapy, which was associated with a response rate of 45.5% and a disease control rate of 72.7%. After a median follow-up period of 53.0 months, the 5-year DT-specific survival rate in patients with stage IV disease was 71.4%; in contrast, the rate in patients with other stages was 100%. Four-stage IV patients died of DT due to uncontrollable rapid progression. No cytotoxic chemotherapy was administered; however, incomplete resection was performed in three cases. CONCLUSION: Our findings will provide clues that may help physicians in selecting the optimal strategy for this rare disease.

[A Case of Duodenum Dissemination after Surgery for Transverse Colon Carcinoma Which Was Unresponsive to Chemotherapy, but Immunotherapy Was Significantly Effective].

The patient was a 73-year-old woman who received surgery for transverse colon cancer(laparoscopic right hemicolectomy) in December 2014. Histopathologic examination findings were tub2, pT4b, pN1, sH0, sM0, ly2, v0, Stage III a. XELOX 2 courses→FOLFIRI plus panitumumab(Pmab)12 courses was performed after surgery. Stenosis due to duodenum dissemination was observed in the follow-up period(December 2015), and a laparoscopic gastrojejunostomy was performed. Later, the patient's tumor marker value significantly increased, and enlargement of duodenum dissemination was observed by abdominalCT. From April 2016, treatment was switched to mFOLFOX6 plus Pmab and 5 courses were subsequently performed. Still, metastasis to the abdominal wall was observed. According to results of the microsatellite instability test of MSIH, the patient was registered into a clinicaltrialfor pembrolizumab, which is anti-PD-1, and administration began from June. The tumor marker value significantly decreased, and a reduction in the size of the duodenum dissemination over time could also be observed by abdominal CT. Significant tumor reduction was observed, indicating that immune therapy may be significantly effective in some cases.

Risk Factors for the Development of Desmoid Tumor After Colectomy in Patients with Familial Adenomatous Polyposis: Multicenter Retrospective Cohort Study in Japan.

BACKGROUND: Desmoid tumor (DT) is the primary cause of death in patients with familial adenomatous polyposis (FAP) after restorative proctocolectomy. This study aimed to identify risk factors for DT in a Japanese population. METHODS: Clinical data for 319 patients with FAP undergoing first colectomy from 2000 to 2012 were reviewed retrospectively. RESULTS: Two hundred seventy-seven FAP patients were included in this study. Thirty-nine (14.1 %) patients developed DT. Occurrence sites were the intraperitoneal region in 25 (64.1 %) cases, intraperitoneal region and abdominal wall in three (7.7 %), and abdominal wall in nine (23.1 %). The mean period from surgery to DT development was 26.3 months (range 4-120 months). Gender (female vs. male, p = 0.03), age at surgery (>30 vs. ≤30 years, p = 0.02), purpose of surgery (prophylactic vs. cancer excision, p = 0.01), and surgical procedure (proctocolectomy [ileoanal anastomosis (IAA), ileoanal canal anastomosis (IACA), total proctocolectomy (TPC)] vs. total colectomy [ileorectal anastomosis, partial colectomy]; p = 0.03) significantly influenced the estimated cumulative risk of developing DT at 5 years after surgery. Conversely, approach (laparoscopic vs. open, p = 0.17) had no significant effect on the increased risk of DT occurrence. In multivariate analysis, female gender, with a hazard ratio of 2.2 (p = 0.02,) and proctocolectomy (IAA, IACA, TPC), with a hazard ratio of 2.2 (p = 0.03), were independent risk factors for DT incidence after colectomy. CONCLUSIONS: Female gender and proctocolectomy (IAA, IACA, TPC) were independent risk factors for developing DT after colectomy in patients with FAP.

A proposed staging system and stage-specific interventions for familial adenomatous polyposis.

BACKGROUND AND AIMS: It is not possible to accurately count adenomas in many patients with familial adenomatous polyposis (FAP). Nevertheless, polyp counts are critical in evaluating each patient's response to interventions. However, the U.S. Food and Drug Administration no longer recognizes the decrease in polyp burden as a sufficient chemoprevention trial treatment endpoint requiring a measure of "clinical benefit." To develop endpoints for future industry-sponsored chemopreventive trials, the International Society for Gastrointestinal Hereditary Tumors (InSIGHT) developed an FAP staging and intervention classification scheme for lower-GI tract polyposis. METHODS: Twenty-four colonoscopy or sigmoidoscopy videos were reviewed by 26 clinicians familiar with diagnosis and treatment of FAP. The reviewers independently assigned a stage to a case by using the proposed system and chose a stage-specific intervention for each case. Our endpoint was the degree of concordance among reviewers staging and intervention assessments. RESULTS: The staging and intervention ratings of the 26 reviewers were highly concordant (ρ = 0.710; 95% credible interval, 0.651-0.759). Sixty-two percent of reviewers agreed on the FAP stage, and 90% of scores were within ±1 stage of the mode. Sixty percent of reviewers agreed on the intervention, and 86% chose an intervention within ±1 level of the mode. CONCLUSIONS: The proposed FAP colon polyposis staging system and stage-specific intervention are based on a high degree of agreement on the part of experts in the review of individual cases of polyposis. Therefore, reliable and clinically relevant means for measuring trial outcomes can be developed. Outlier cases showing wide scatter in stage assignment call for individualized attention and may be inappropriate for enrollment in clinical trials for this reason.

Malnutrition in rectal cancer patients receiving preoperative chemoradiotherapy is common and associated with treatment tolerability and anastomotic leakage.

PURPOSE: This study assessed the incidence of malnutrition caused by preoperative chemoradiotherapy (CRT) in rectal cancer patients, which is seemingly underestimated; however, malnutrition affects treatment tolerability, postoperative complications, including anastomotic leakage (AL), and oncological outcomes. METHODS: Between January 2008 and December 2014, 54 consecutive patients with T3-4, N0-2, M0-1 resectable rectal cancer received CRT comprising 45 Gy radiotherapy and S-1 alone or with irinotecan for 5 weeks and then underwent curative surgery with diverting or permanent stomas 6-8 weeks after CRT. We assessed malnutrition after completion of CRT (5-6 weeks after CRT start date) and at surgery (11-14 weeks after CRT start date), defining weight loss as ≥5 % of pre-CRT weight; this definition differs from commonly used criteria for adverse events. We evaluated the incidence of malnutrition associated with CRT and influence of malnutrition on treatment tolerability, AL, and disease-free survival (DFS). We also assessed the influence of CRT on the rate of postoperative complications by comparing the study group with 61 patients who had undergone excision with diverting or permanent stomas alone. RESULTS: Malnutrition was observed in 51 % of patients after CRT and in 29 % at surgery. Malnutrition after CRT was associated with treatment tolerability, and malnutrition at surgery was significantly associated with AL, which significantly influenced DFS in stage 1-3 patients. CONCLUSION: Malnutrition caused by CRT is common and is associated with treatment tolerability and AL. Nutritional assessment and support seem indispensable for the rectal cancer patients receiving CRT.

Therapeutic approaches for patients with coexisting familial adenomatous polyposis and colorectal cancer.

OBJECTIVE: Colorectal cancer is a major cause of death in patients with familial adenomatous polyposis. Despite evidence for prophylactic colectomy, there is no ideal therapy for patients with coexisting familial adenomatous polyposis and colorectal cancer. We evaluated the correlation between surgery for familial adenomatous polyposis and multimodal treatment for colorectal cancer, and clarified prognosis of Japanese patients with familial adenomatous polyposis and colorectal cancer. METHODS: We retrospectively reviewed data from 303 patients who underwent colorectal surgery for familial adenomatous polyposis between 2000 and 2012. RESULTS: Overall, 172 patients had colorectal cancer. The most common procedure for familial adenomatous polyposis was restorative proctocolectomy with ileal pouch anal anastomosis, irrespective of colorectal cancer. Partial colectomy was more frequent in patients with than without colorectal cancer (8.7% and 0%, respectively). Ileal pouch anal anastomosis was frequently (60.6%) performed in patients with Stage I-III colorectal cancer. Overall, 12 of 20 patients with Stage IV colorectal cancer underwent metastasectomy; six patients simultaneously and six metachronously. There were fewer cases of ileal pouch anal anastomosis, but more total colectomy with ileorectal anastomosis was performed metachronously, compared with simultaneous metastasectomy (P = 0.006). More cytotoxic (P = 0.006) and molecular (P = 0.03) agents were administered to the ileorectal anastomosis/partial colectomy patients, compared with total proctocolectomy/ileal pouch anal anastomosis patients. A 5-year overall survival was 100% in Stage 0/I, 89.8% in Stage II, 87.9% in Stage III and 48.4% in Stage IV. CONCLUSIONS: In patients with familial adenomatous polyposis and colorectal cancer, primary surgery, metastasectomy and chemotherapy could be compatible with standard surgical approaches for familial adenomatous polyposis . However, modifying surgical procedures for familial adenomatous polyposis might help multimodality therapy for Stage IV colorectal cancer to prolong survival.

Upper gastrointestinal tumours in Japanese familial adenomatous polyposis patients.

OBJECTIVE: The upper gastrointestinal characteristics in Japanese familial adenomatous polyposis patients have not yet been clarified. The aim of the present study was to elucidate these characteristics in Japanese familial adenomatous polyposis patients. METHODS: This study was conducted by the study group for familial adenomatous polyposis in the Japanese Society for Cancer of the Colon and Rectum. Familial adenomatous polyposis patients who underwent surgical resection from 2000 to 2012 were included in the study. RESULTS: In total, 303 familial adenomatous polyposis patients were enrolled, with 265 cases of classical familial adenomatous polyposis (≥100 adenomas) and 38 cases of attenuated familial adenomatous polyposis (<100 adenomas). Fundic gland polyps were significantly more common in classical familial adenomatous polyposis than in attenuated familial adenomatous polyposis; however, gastric cancer was significantly less common in classical familial adenomatous polyposis than in attenuated familial adenomatous polyposis. Gastric cancer and duodenal adenoma were significantly more common in familial adenomatous polyposis patients with gastric adenoma than in those without gastric adenoma. Duodenal cancer was detected in 7 of 72 familial adenomatous polyposis patients with duodenal adenoma. The median tumour risk in 50-year-old familial adenomatous polyposis patients was 55.3, 21.8, 3.8, 39.2 and 7.7% for fundic gland polyp, gastric adenoma, gastric cancer, duodenal adenoma and duodenal cancer, respectively. CONCLUSIONS: Upper gastrointestinal tumours/polyps were frequently found in familial adenomatous polyposis patients, and their incidences were correlated; however, the frequency of gastric cancer in Japanese familial adenomatous polyposis patients was similar to that in the general population.

Long-Term Functional Outcomes of Total Mesorectal Excision Following Chemoradiotherapy for Lower Rectal Cancer: Stapled Anastomosis versus Intersphincteric Resection.

AIMS: To compare the long-term functional outcomes of total mesorectal excision following chemoradiotherapy for lower rectal cancer between stapled anastomosis and intersphincteric resection (ISR). METHODS: A total of 105 of 170 sphincter-preserving patients found to be disease-free and anal functional patients were assessed at 6.5 years (range 2.4-13.0 years) of follow-up after surgery. Of these subjects, 87 (double stapling technique [DST]: 41; ISR: 46) of the 105 patients (82.9%) responded to the questionnaire on the low anterior resection syndrome score (LARS score). RESULTS: The total LARS scores in the DST and ISR groups were not significantly different (Major/Minor/No LARS = 23/14/4 and 31/10/5, p = 0.431). When considering each item of the LARS, ISR was associated with poorer incontinence scores than DST. Conversely, the scores for the frequency of bowel movement, clustering and urgency were not different between the 2 groups. In addition, in the multivariate analysis, the tumor distance from the anal verge and postoperative period was independently associated with Major LARS. CONCLUSION: In this study, we demonstrate the long-term functional outcomes of irradiated lower rectal cancer reconstructed with DST and ISR. Bowel function improves over time; therefore, long-term patient follow-up is important.