Treatment Strategy For Rectal Cancer Research Articles

Application status and progress of intraoperative nerve monitoring in pelvic autonomic nerve preserving radical resection of rectal cancer

The current treatment strategy for rectal cancer is a comprehensive treatment centered on surgery. The application of total mesorectal excision (TME) has significantly reduced the local recurrence rate and improved the survival prognosis, but a series of pelvic organ dysfunction caused by pelvic autonomic nerve injury during the operation will reduce the postoperative quality of life of patients. Pelvic autonomic nerve preserving (PANP) radical proctectomy has emerged, but the biggest challenge in the implementation process of this technology is the accurate identification of nerves. A series of studies have shown that pelvic intraoperative autonomic monitoring (pIONM) can effectively assist surgeons to identify nerves, The purpose of this article is to introduce the function of pelvic autonomic nerve, the clinical manifestation of postoperative pelvic dysfunction and its relationship with nerve injury, the key points of implementing PANP, and the current situation and research progress of pIONM technology application.

Timing of Surgery and Pathologic Complete Response (pCR) after Completing Total Neoadjuvant Therapy for Rectal Adenocarcinoma: A Retrospective Study of the National Cancer Database

Total neoadjuvant therapy (TNT) is a treatment strategy for rectal cancer that includes a course of multiagent chemotherapy and a separate course of radiation +/- concurrent chemotherapy before definitive surgery. The use of TNT has increased in recent years and carries the potential for improved sphincter preservation and a significant risk reduction of locoregional recurrence. However, the influence of rest period from end of radiation to surgery after TNT is unclear. The objective of this study was to evaluate the relationship between rest period and pCR using data from the National Cancer Database. We hypothesized that longer duration of rest period before surgery will be positively associated with pCR. Patients aged 18 years and older diagnosed with primary rectal cancer between 2016 and 2020, who underwent an NCCN-recommended TNT regimen followed by definitive surgery at a Commission on Cancer-accredited facility were retrospectively analyzed in the current study. We included 5,997 patients who met the following inclusion criteria: clinical stage T2 and above, any N stage, M0, adenocarcinoma histology, and not receiving any adjuvant therapy. Logistic regression methods were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between duration of rest period and pCR. Restricted cubic splines were used to evaluate potential non-linear relationship between duration of rest period and pCR. The median age of the study sample was 57 years old (interquartile range: 49 - 65), with majority of them being males (62.3%) and reporting Non-Hispanic White race and ethnicity (75.5%). The overall pCR rate was 18.6%. The majority received long-course radiation (76.7%) and induction chemotherapy (86.3%). In multivariable adjusted models, there was a non-linear relationship between duration of rest period and pCR (p = 0.036). Rest periods of 8-24 weeks were significantly associated with elevated odds of pCR with the odds highest at 14 weeks (OR = 2.86, 95% CI: 1.20 - 6.84) when compared to rest periods of less than a week. There was no difference in pCR between long-course vs. short course radiation and no difference between those who received induction chemotherapy vs. consolidative chemotherapy. Although the rest period is inherently longer when radiation therapy precedes consolidative chemotherapy, the order of chemotherapy to radiation itself did not impact pCR but rather the duration of rest period. These data demonstrate an ideal window for surgery to achieve pCR in rectal cancer in the TNT era and the need for further prospective investigations of optimal rest period before surgery to achieve maximal pCR with homogenous TNT treatment regimens.

Size and depth of residual tumor after neoadjuvant chemoradiotherapy in rectal cancer - implications for the development of new imaging modalities for response assessment.

With the shift towards organ preserving treatment strategies in rectal cancer it has become increasingly important to accurately discriminate between a complete and good clinical response after neoadjuvant chemoradiotherapy (CRT). Standard of care imaging techniques such as CT and MRI are well equipped for initial staging of rectal tumors, but discrimination between a good clinical and complete response remains difficult due to their limited ability to detect small residual vital tumor fragments. To identify new promising imaging techniques that could fill this gap, it is crucial to know the size and invasion depth of residual vital tumor tissue since this determines the requirements with regard to the resolution and imaging depth of potential new optical imaging techniques. We analyzed 198 pathology slides from 30 rectal cancer patients with a Mandard tumor regression grade 2 or 3 after CRT that underwent surgery. For each patient we determined response pattern, size of the largest vital tumor fragment or bulk and the shortest distance from the vital tumor to the luminal surface. The response pattern was shrinkage in 14 patients and fragmentation in 16 patients. For both groups combined, the largest vital tumor fragment per patient was smaller than 1mm for 38% of patients, below 0.2mm for 12% of patients and for one patient as small as 0.06mm. For 29% of patients the vital tumor remnant was present within the first 0.01mm from the luminal surface and for 87% within 0.5mm. Our results explain why it is difficult to differentiate between a good clinical and complete response in rectal cancer patients using endoscopy and MRI, since in many patients submillimeter tumor fragments remain below the luminal surface. To detect residual vital tumor tissue in all patients included in this study a technique with a spatial resolution of 0.06mm and an imaging depth of 8.9mm would have been required. Optical imaging techniques offer the possibility of detecting majority of these cases due to the potential of both high-resolution imaging and enhanced contrast between tissue types. These techniques could thus serve as a complimentary tool to conventional methods for rectal cancer response assessment.

Economical Evaluation of Cancer Types Using Intensity-Modulated Radiation Therapy Compared to 3D Conformal Radiation Therapy: A Systematic Review.

Cancer is the second most common cause of death worldwide. Economic evaluation of cancer treatment to reduce costs can save the health care system millions of dollars while optimizing care. Therefore, this systematic review aimed to study the economic evaluation of cancer treatment using intermediate intensity radiation therapy (IMRT) compared to conventional 3D conformal radiation therapy (3D-CRT). Literatures from PubMed, Embase, Cochran Library, Google scholar, Scopus and Iranian databases were retrieved since Jan 2000 to Apr 2020 for eligible English studies. The quality of the studies was evaluated using Cheers' checklist and then the textual data were analyzed manually by content analysis method. Overall, 1790 articles were retrieved, of which 12 studies were reviewed. The article quality score ranged from 14.5 to 23 out of a maximum of 24 points. Eleven studies referred to cost-effectiveness analysis and one study referred to cost-utility analysis. Studies have been conducted in the United States, Canada, Australia, Brazil, the Netherlands, the United Kingdom, and Hungary. IMRT appears to be a cost-effective treatment strategy for rectal cancer, soft tissue sarcoma, and localized carcinoma of the pharynx, and for prostate cancer in terms of prolonging survival, but it is a cost-effective treatment strategy for head cancer. In addition, the neck was not in India's cancer control program. The results can help to decide whether to use radiation therapy and radiotherapy in the standard treatment path. Furthermore, they underline that IMRT treatment technique was cost effective for a long-time care service.

Abstract P021: Association of social determinants of health and healthcare-related factors with delayed total neoadjuvant therapy among rectal cancer patients from the national cancer database

Abstract Total neoadjuvant therapy (TNT) is a treatment strategy for rectal cancer that includes a course of chemotherapy and a separate course of chemoradiation before definitive surgery. The use of TNT has increased in recent years and carries the potential for improved sphincter preservation and a significant risk reduction of locoregional recurrence. One criterion of the National Accreditation Program for Rectal Cancer is to begin definitive treatment within 60 days of a patient’s diagnosis of rectal cancer. The objective of this study was to evaluate the association of social determinants of health and healthcare-related factors with starting TNT 60 days or more after diagnosis using data from the National Cancer Database (NCDB). Patients aged 18 years and older diagnosed with primary rectal cancer between 2016 and 2019, who underwent NCCN recommended TNT regimen followed by definitive surgery at a Commission on Cancer (CoC)-accredited facility and did not die before receiving surgery were eligible for the current study. We included 3,210 patients in the analytic sample who did not have the following conditions: clinical stage IV, clinical stage T1N0 or lower, non-adenocarcinoma histology, and adjuvant therapy use. Logistic regression models were used to estimate the odds ratio (OR) and 95% confidence intervals (CI) for factors potentially associated with starting TNT more than 60 days after a cancer diagnosis. The median age of patients included in the study was 57 years old, with a majority of them starting TNT within 60 days (87.5%), were males (62.3%), and reported as Non-Hispanic White race and ethnicity (76.7%). Furthermore, 35.0% had a median household income of $63,333 or more, 57.7% had private insurance/managed care, 65.0% traveled within 30 miles to their treatment facility, and 49.1% lived in a zip code where less than 10.9% of adults age 25 or older did not graduate from high school. In multivariable models, factors positively associated with starting TNT after 60 days or more were uninsured status (OR 2.93, CI: 1.84, 4.67), living in a zip code with more than 10.8% of adults age 25 or older not graduating from high school (OR 1.66, CI: 1.22, 2.25), traveling more than 30 miles to the treatment facility (OR 1.63, CI: 1.20, 2.20), treatment with an academic/research program (OR 1.51, CI: 1.13, 2.02), Medicaid as primary insurance (OR 1.50, CI: 1.03, 2.19), Hispanic ethnicity (OR 1.44, CI: 1.00, 2.07), male (OR 1.28, CI: 1.00, 1.65) and age (1.02, CI: 1.01, 1.04). In conclusion, results from this study show that social determinants of health and other healthcare-related factors are significantly associated with those who started TNT more than 60 days after a rectal cancer diagnosis. Further investigation is ongoing to understand the impact of delays in TNT and other treatment regimens for rectal cancer. Citation Format: Megan T. Mai, Zheng Shi, Duke Appiah. Association of social determinants of health and healthcare-related factors with delayed total neoadjuvant therapy among rectal cancer patients from the national cancer database. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P021.

Development of a method for digital assessment of tumor regression grade in patients with rectal cancer following neoadjuvant therapy

Neoadjuvant chemo-radiotherapy (nCRT) followed by surgical resection is the standard treatment strategy in patients with locally advanced rectal cancer (RC). The pathological effect of nCRT is assessed by determining the tumor regression grade (TRG) of the resected tumor. Various methods exist for assessing TRG and all are performed manually by the pathologist with an accompanying risk of interobserver variation. Automated digital image analysis could be a more objective and reproducible approach to evaluate TRG. This study aimed at developing a digital method to assess TRG in RC following nCRT, and correlate the results to the currently used Mandard method. A deep learning-based semi-automatic Epithelium-Tumor area Percentage (ETP) algorithm enabling quantification of tumor regression by determining the percentage of residual tumor epithelium out of the total tumor area was developed. The ETP was quantified in 50 cases treated with nCRT and 25 cases with no prior nCRT served as controls. Median ETP was 39.25% in untreated compared with 6.64% in patients who received nCRT (P < .001). The ETP of the resected tumors treated with nCRT increased along with increasing Mandard grade (P < .001). As new treatment strategies in RC are emerging, performing an accurate and reproducible evaluation of TRG is important in the assessment of treatment response and prognosis. TRG is often used as an outcome point in clinical trials. The ETP algorithm is capable of performing a precise and objective value of tumor regression.

A modified method for resected specimen processing in rectal cancer: Semi-opened with transverse slicing for measuring of the circumferential resection margin.

Circumferential resection margin (CRM) is essential for oncological quality assessment in rectal cancer surgery. CRM represents a surrogate parameter for oncological outcomes and is important for stratifying treatment strategies in Western nations. In Japan, the mesentery is removed for specimen processing in order to extract as many lymph nodes (LNs) as possible; consequently, CRM cannot be measured. Given the diversification of treatment strategies for rectal cancer, the lack of measurement of CRM to assess surgical outcomes is a crucial issue that must be resolved. Therefore, it is necessary to establish a method enabling measurement of CRM while enjoying the advantages of the Japanese method. In the method we developed, the mesentery is removed from the rectum more than 2 cm away from the tumor, and the vicinity of the tumor is circularized. It is necessary to investigate the usefulness of this method prospectively in a multi-center study.

A meta-analysis of the watch-and-wait strategy versus total mesorectal excision for rectal cancer exhibiting complete clinical response after neoadjuvant chemoradiotherapy

BackgroundSome clinical researchers have reported that patients with cCR (clinical complete response) status after neoadjuvant chemoradiotherapy (nCRT) could adopt the watch-and-wait (W&W) strategy. Compared with total mesorectal excision (TME) surgery, the W&W strategy could achieve a similar overall survival. Could the W&W strategy replace TME surgery as the main treatment option for the cCR patients? By using the meta-analysis method, we evaluated the safety and efficacy of the W&W strategy and TME surgery for rectal cancer exhibiting cCR after nCRT.MethodsWe evaluated two treatment strategies for rectal cancer with cCR after nCRT up to July 2021 by searching the Cochrane Library, PubMed, Wanfang, and China National Knowledge Infrastructure (CNKI) databases. Clinical data for primary outcomes (local recurrence, cancer-related death and distant metastasis), and secondary outcomes (disease-free survival (DFS) and overall survival (OS)) were collected to evaluate the efficacy and safety in the two groups.ResultsWe included nine studies with 818 patients in the meta-analysis, and there were five moderate-quality studies and four high-quality studies. A total of 339 patients were in the W&W group and 479 patients were in the TME group. The local recurrence rate in the W&W group was greater than that in the TME group in the fixed-effects model (OR 8.54, 95% CI 3.52 to 20.71, P < 0.001). The results of other outcomes were similar in the two groups.ConclusionThe local recurrence rate of the W&W group was greater than that in the TME group, but other results were similar in the two groups. With the help of physical examination and salvage therapy, the W&W strategy could achieve similar treatment effects with the TME approach.Trial registrationProtocol registration number: CRD42021244032.

Trimodal Therapy Approaches for Localized Rectal Cancer

Excellent long-term outcomes and manageable toxicity are being achieved with contemporary treatment strategies for rectal cancer. Short-course radiotherapy is now an acceptable standard. Total neoadjuvant therapy (TNT), which incorporates induction or consolidation chemotherapy, has improved the delivery of treatment regiments. TNT is now a standard of care, although the sequencing of radiation and chemotherapy in TNT, appropriate amount of chemotherapy in TNT, and addition of irinotecan to the regimen are still being debated. Nonoperative management of rectal cancer appears to be a safe option for select patients, but it is not yet an NCCN recommendation. In addition, the omission of radiation is being evaluated as a treatment option in some cases.

Evidence-based surgery of rectal cancer

Over the past four decades, the treatment algorithms for rectal cancer have fundamentally changed, which resulted in aconsiderable improvement of oncological outcomes. In this context, the surgical concept of total mesorectal excision and the implementation of multimodal treatment strategies represent key milestones. These improvements were complemented by astandardized histopathological work-up of the surgical specimen and the introduction of high-resolution magnetic resonance imaging (MRI) diagnostics. In addition, novel surgical techniques have been introduced, such as laparoscopic and robotic rectal resection. Other technological innovations include intraoperative pelvic neuromonitoring and fluorescence imaging. This review highlights the current evidence for selected, sometimes controversially discussed principles of surgical treatment strategies in rectal cancer.

Optimal treatment strategy for rectal cancer based on the risk factors for recurrence patterns.

For rectal cancer, multimodality therapeutic approach is necessary to prevent local recurrence and distant metastasis. However, the efficacy of additional treatments, such as neoadjuvant chemoradiotherapy (nCRT), neoadjuvant chemotherapy (NAC), and lateral pelvic lymph node dissection (LPLND), has not been scrutinized. Recurrence patterns were categorized into local recurrence and distant metastasis. Local recurrence was classified into two types: (1) pelvic cavity recurrence and (2) LPLN recurrence. First, we analyzed the risk factors for each recurrence pattern. Second, based on the status of clinically suspected involvement of circumferential resection margin (cCRM), the efficacy of additional treatments was investigated. A total of 240 patients was enrolled. nCRT was performed for 25 (10%), NAC was for 46 (19%), and LPLND was for 35 patients (15%). As the recurrence patterns, pelvic cavity recurrence occurred in 15 (6%), LPLN recurrence in 8 (3%), and distant metastasis in 42 patients (18%). Five-year overall survival and relapse-free survival were 87% and 70%, respectively. Multivariate analysis indicated that pelvic cavity recurrence was associated with cCRM status and tumor histology, that LPLN recurrence was with serum carcinoembryonic antigen level and LPLN swelling, and that distant metastasis was with clinical N category. In the cCRM-positive subgroup (n = 66), cumulative rate of pelvic cavity recurrence was lower in the nCRT group than in the NAC or non-NAC/nCRT group (P = 0.02 and 0.09, respectively). cCRM status was associated with pelvic cavity recurrence, and LPLN swelling was with LPLN recurrence. nCRT could reduce pelvic cavity recurrence in cCRM-positive subgroup.

Health-related quality of life in rectal cancer patients undergoing neoadjuvant chemoradiation with delayed surgery versus short-course radiotherapy with immediate surgery: a propensity score-matched cohort study

Background: Neoadjuvant chemoradiation with delayed surgery (CRT-DS) and short-course radiotherapy with immediate surgery (SCRT-IS) are two commonly used treatment strategies for rectal cancer. However, the optimal treatment strategy for patients with intermediate-risk rectal cancer remains a discussion. This study compares quality of life (QOL) between SCRT-IS and CRT-DS from diagnosis until 24 months after treatment.Methods: In a prospective colorectal cancer cohort, rectal cancer patients with clinical stage T2-3N0-2M0 undergoing SCRT-IS or CRT-DS between 2013 and 2017 were identified. QOL was assessed using EORTC-C30 and EORTC-CR29 questionnaires before the start of neoadjuvant treatment (baseline) and at 3, 6, 12, 18 and 24 months after. Patients were 1:1 matched using propensity sore matching. Between- and within-group differences in QOL domains were analyzed with linear mixed-effects models. Symptoms and sexual interest at 12 and 24 months were compared using logistic regression models.Results: 156 of 225 patients (69%) remained after matching. The CRT-DS group reported poorer emotional functioning at 3, 6, 12, 18 and 24 months (mean difference with SCRT-IS: −9.4, −12.1, −7.3, −8.0 and −7.9 respectively), and poorer global health, physical-, role-, social- and cognitive functioning at 6 months (mean difference with SCRT-IS: −9.1, −9.8, −14.0, −9.2 and −12.6, respectively). Besides emotional functioning, all QOL domains were comparable at 12, 18 and 24 months. Within-group changes showed a significant improvement of emotional functioning after baseline in the SCRT-IS group, whereas only a minor improvement was observed in the CRT-DS group. Symptoms and sexual interest in male patients at 12 and 24 months were comparable between the groups.Conclusions: In rectal cancer patients, CRT-DS may induce a stronger decline in short-term QOL than SCRT-IS. From 12 months onwards, QOL domains, symptoms and sexual interest in male patients were comparable between the groups. However, emotional functioning remained higher after SCRT-IS than after CRT-DS.

Adoption of Total Neoadjuvant Therapy for Locally Advanced Rectal Cancer

Treatment of locally advanced rectal (LARC) cancer involves chemoradiation, surgery, and chemotherapy. The concept of total neoadjuvant therapy (TNT), in which chemoradiation and chemotherapy are administered prior to surgery, has been developed to optimize delivery of effective systemic therapy aimed at micrometastases. To compare the traditional approach of preoperative chemoradiation (chemoRT) followed by postoperative adjuvant chemotherapy with the more recent TNT approach for LARC. A retrospective cohort analysis using Memorial Sloan Kettering Cancer Center (MSK) records from 2009 to 2015 was carried out. A total of 811 patients who presented with LARC (T3/4 or node-positive) were identified. Of the 811 patients, 320 received chemoRT with planned adjuvant chemotherapy and 308 received TNT (induction fluorouracil- and oxaliplatin-based chemotherapy followed by chemoRT). Treatment and outcome data for the 2 cohorts were compared. Dosing and completion of prescribed chemotherapy were assessed on the subset of patients who received all therapy at MSK. Of the 628 patients overall, 373 (59%) were men and 255 (41%) were women, with a mean (SD) age of 56.7 (12.9) years. Of the 308 patients in the TNT cohort, 181 (49%) were men and 127 (49%) were women. Of the 320 patients in the chemoRT with planned adjuvant chemotherapy cohort, 192 (60%) were men and 128 (40%) were women. Patients in the TNT cohort received greater percentages of the planned oxaliplatin and fluorouracil prescribed dose than those in the chemoRT with planned adjuvant chemotherapy cohort. The complete response (CR) rate, including both pathologic CR (pCR) in those who underwent surgery and sustained clinical CR (cCR) for at least 12 months posttreatment in those who did not undergo surgery, was 36% in the TNT cohort compared with 21% in the chemoRT with planned adjuvant chemotherapy cohort. Our findings provide additional support for the National Comprehensive Cancer Network (NCCN) guidelines that categorize TNT as a viable treatment strategy for rectal cancer. Our data suggest that TNT facilitates delivery of planned systemic therapy. Long-term follow-up will determine if this finding translates into improved survival. In addition, given its high CR rate, TNT may facilitate nonoperative treatment strategies aimed at organ preservation.

Treatment strategies for rectal cancer with synchronous liver metastases: surgical and oncological outcomes with propensity-score analysis

The optimal sequence of surgery for rectal cancer (RC) with synchronous liver metastases (SLM) is controversial. The primary objective was to explore differences between the rectum first (RF) and the liver first strategy (LF) to achieve the complete resection (CR) of both tumors. Patients diagnosed of RC with resectable or potentially resectable SLM were included. Data collected prospectively were analyzed with an intention-to-treat perspective, adjusting for between-sample differences (propensity score). The complete resection rate (CRR) was the main outcome variable. During a 5-year period, 23 patients underwent the LF strategy and 24 patients the RF strategy. Median overall survival (OS) was 32months in the LF group and 41months in the RF group (p=0.499), and was 51 and 17months, respectively, for patients achieving or not achieving CR of both tumors (p<0.001). CRR's were 65% in liver first group and 63% in rectum first group, (p=0.846). No between-strategy differences in morbidity or duration of treatment were observed. This study supports the notion that the achievement of CR of RC and SLM should be the goal of oncological treatment. Both RF and LF strategies are feasible and safe, but no between-strategy differences have been found in the CRR.

Two countries − two treatment strategies for rectal cancer

Two countries − two treatment strategies for rectal cancer

Two countries – Two treatment strategies for rectal cancer

Background and purposeTrials in rectal cancer have shown that radiotherapy (RT) decreases local recurrence rates, whereas the effects on survival are uncertain. Swedish and Norwegian oncologists have had different treatment recommendations. The aim was to evaluate local recurrence rates and survival in the two countries. Patients and methodsBetween 1995 and 2012 rectal cancer patients registered in Sweden and Norway were analyzed, presenting population-based “real world” data. ResultsTotally 29,029 Swedish and 15,456 Norwegian patients were analyzed. Resection for cure was performed in two-thirds of the patients. RT was given to 49% of Swedish patients, mainly short-course RT and to 26% of Norwegian patients, predominantly chemoradiotherapy (CRT). In Sweden, the proportion irradiated was stable whereas in Norway, an increase from 10% to 40% was seen. Local 5-year recurrence rates were initially higher in Norway (12%) than in Sweden (8%), whereas they were equally low (4%) during the latter time. No survival differences were seen, however, survival improved with time in both countries. ConclusionsTwo entirely different approaches to preoperative therapy resulted in similar survival with initially higher local recurrence rates in Norway, but similarly low rates in later years. This raises questions about optimal RT rates and regimens.

Imaging in Colorectal Cancer: Progress and Challenges for the Clinicians.

The use of imaging in colorectal cancer (CRC) has significantly evolved over the last twenty years, establishing important roles in surveillance, diagnosis, staging, treatment selection and follow up. The range of modalities has broadened with the development of novel tracer and contrast agents, and the fusion of technologies such as positron emission tomography (PET) and computed tomography (CT). Traditionally, the most widely used modality for assessing treatment response in metastasised colon and rectal tumours is CT, combined with use of the RECIST guidelines. However, a growing body of evidence suggests that tumour size does not always adequately correlate with clinical outcomes. Magnetic resonance imaging (MRI) is a more versatile technique and dynamic contrast-enhanced (DCE)-MRI and diffusion-weighted (DW)-MRI may be used to evaluate biological and functional effects of treatment. Integrated fluorodeoxyglucose (FDG)-PET/CT combines metabolic and anatomical imaging to improve sensitivity and specificity of tumour detection, and a number of studies have demonstrated improved diagnostic accuracy of this modality in a variety of tumour types, including CRC. These developments have enabled the progression of treatment strategies in rectal cancer and improved the detection of hepatic metastatic disease, yet are not without their limitations. These include technical, economical and logistical challenges, along with a lack of robust evidence for standardisation and formal guidance. In order to successfully apply these novel imaging techniques and utilise their benefit to provide truly personalised cancer care, advances need to be clinically realised in a routine and robust manner.

Revisiting the treatment strategy for rectal cancer through the pattern of local recurrence

BackgroundLocal recurrence after rectal cancer surgery is categorized as lymphatic spread (pelvic sidewall node (PSN)) and other types. This study aimed to investigate the risk factors associated with different patterns of local recurrence and to optimize the treatment strategy after rectal cancer surgery. MethodsPatients with cStage I–III rectal cancer who underwent surgery at our institute were included in this study. Local recurrence was categorized as follows: (1) PSN recurrence and (2) “other” types of local recurrence. The risk factors associated with each type of recurrence (metastasis) were investigated. ResultsA total of 212 patients with mid/low rectal cancer were included in this study (cStage I: 66; cStage II/III: 146). Additional treatment was employed in selected patients with high-risk features (n = 45; pelvic sidewall dissection: 18; preoperative chemo (radio)therapy: 37). Potential lateral node metastasis was significantly associated with PSN enlargement on imaging findings (no/yes, odds ratio (OR): 9.1; p = 0.007). The “other” local recurrence type was significantly associated with 3 different factors as follows: clinical circumferential resection margin (no/yes; OR: 18.0; p = 0.001), tumor histology (well and moderately/poorly differentiated, OR: 17.3; p = 0.008), and tumor diameter (p = 0.018). Among 146 cStage II/III patients, 66 (45.2%) who did not have any of the abovementioned 4 risk factors experienced no local recurrence even when no additional treatment was employed. ConclusionsRisk factors may differ for different types of postoperative local recurrence patterns in rectal cancer. Recognizing these risk factors based on pretreatment findings can allow the optimization of treatment strategies for rectal cancer.

PV-0122: Clinical factors as a selection tool for organ-preserving treatment strategies in rectal cancer

PV-0122: Clinical factors as a selection tool for organ-preserving treatment strategies in rectal cancer

Oncologic Outcomes according to the Treatment Strategy in Radiologic Complete Responders after Neoadjuvant Chemoradiation for Rectal Cancer

Objective: This study aimed to compare the oncologic outcomes between treatment strategies for rectal cancer [radical surgery, local excision (LE), and the wait-and-see approach] in radiologic complete responders after neoadjuvant chemoradiation (nCRT). Methods: We retrospectively reviewed rectal cancer patients and included 52 radiologic complete responders after nCRT defined as no residual tumor or residual fibrosis and no suspicious metastatic lymph nodes on magnetic resonance imaging (MRI). Clinicopathologic features and oncologic outcomes were compared according to the treatment strategies. Results: The median follow-up period was 41 months (range, 6-80). Twenty-eight patients underwent radical surgery, whereas 16 underwent LE, and 8 were closely monitored without initial surgery. The pathologic complete response rate was 40.9%. Patients who underwent radical surgery showed better prognosis compared to those who underwent LE or wait-and-see (3-year disease-free survival: radical surgery 85.0% vs. LE 62.5%, wait-and-see 75.0%, p = 0.019; 3-year local recurrence-free survival: radical surgery 96.4% vs. LE 67.0%, wait-and-see 75.0%, p = 0.009). After recurrence, patients who underwent salvage surgery showed a relatively good oncologic outcome. Conclusion: Pursuing LE or the wait-and-see approach instead of radical surgery in rectal cancer patients undergoing nCRT may bring about a detrimental oncologic outcome if clinical complete response is solely determined by MRI.