Ten-year survival after pathologic complete response in rectal adenocarcinoma

Smoking and Elevated Preneoadjuvant Chemoradiotherapy Serum Carcinoembryonic Antigen Levels Are Associated With High Tumor Regression Grade and Poor Survival in Patients With Locally Advanced Rectal Cancer

Neoadjuvant chemoradiotherapy (NACRT) is the standard treatment for patients with locally advanced rectal cancer (LARC). Tumor regression grade (TRG) is an essential prognostic factor in determining treatment efficacy. However, the potential factors influencing TRG in patients with rectal cancer who have received NACRT have not been investigated. We conducted a retrospective analysis of patients with LARC who received NACRT followed by surgical resection. We collected data on the patient characteristics, including age, sex, comorbidities, tumor size, lymph node status, time between NACRT and surgery, and pretreatment carcinoembryonic antigen (CEA) levels. TRG was determined on the basis of a pathological assessment of resected specimens, and overall survival (OS) at 5 years was determined. Univariate and multivariate logistic regression models were employed to evaluate the association between the patient characteristics and TRG. Univariate analysis revealed that smoking and prechemoradiotherapy (pre-CRT) and preoperative CEA levels were significantly associated with TRG. In a multivariate analysis, both smoking and higher pre-CRT CEA levels were identified as significant predictors of a high TRG. The hazard ratios were 2.32 (95% confidence interval [CI]: 1.06-5.07, p = 0.036) for smoking and 3.1 (95% CI: 1.69-5.68, p < 0.001) for higher pre-CRT CEA levels. In Kaplan-Meier analysis, the nonsmoker group exhibited higher OS (p = 0.004). Elevated pre-CRT CEA levels and current smoking status were associated with a more than two fold increase in the risk of a higher TRG after NACRT. Moreover, smoking was a significant risk factor for poor OS in patients with LARC following NACRT.

Analysis of clinical and pathological prognostic factors of survival in rectal adenocarcinoma treated with preoperative radiochemotherapy

PURPOSE

To identify the prognostic variables related to the survival of patients operated on for adenocarcinoma of the rectum who underwent preoperative radiochemotherapy (RCT).

METHODS

We studied 70 patients from the Discipline of Surgical Gastroenterology at Escola Paulista de Medicina from 2000 to 2019, with rectal cancer located up to 10 cm from the anal verge and with stages II or III, submitted to preoperative RCT and curative surgery (R0) and with follow-up of at least 12 months. Clinical restaging was performed four to six weeks after the end of neoadjuvant treatment to characterize the degree of clinical tumor regression. Surgery by laparotomy or videolaparoscopy was performed six to 12 weeks after RCT. Primary endpoint were: overall survival (OS), disease-free survival (DFS), metastasis-free survival (MSS), and neoplasm-specific survival (SEN). These were compared with gender, age, carcinoembryonic antigen (CEA) dosage, distance from the tumor to the anal verge, radiation dose, radiotherapy-surgery interval, clinical regression, type of surgery, pT and pN TNM stage tumor, number of nodes, circumferential resection margin, and complete pathological response. Survival was assessed by Kaplan-Meier curves. Univariate and multivariate Cox analyses were calculated to identify factors associated with survival outcomes.

RESULTS

The mean follow-up time was 62 months. The pathological complete response rate was 18.6%. Univariate cox regression showed a significant relationship of CEA equal to or greater than 4 ng/mL with DFS and MFS, pT3/pT4 staging with DFS, MFS and SEN, pN1/N2 with DFS, MFS and SEN and stages II and III with DFS and MFS. Multivariate regression found that CEA, pT, and pN staging are independent prognostic factors for DFS, MFS, and SEN.

CONCLUSION

Carcinoembryonic antigen level prior to radiotherapy, pT staging and pN staging were independent prognostic factors for survival in patients with rectal adenocarcinoma who are treated with preoperative radiochemotherapy.

Total neoadjuvant therapy based on short-course radiotherapy versus standard long-course chemoradiotherapy for locally advanced rectal cancer: a systematic review and meta-analysis of randomized controlled trials

Background

We conducted the meta-analysis to compare the therapeutic effects of total neoadjuvant therapy (TNT) based on short-course radiotherapy followed by consolidation chemotherapy (SCRT/CCT) and long-course chemoradiotherapy (LCCRT) for locally advanced rectal cancer (LARC) according to certain significant randomized controlled trials (RCTs).

Methods

The researchers retrieved several databases, including PubMed, Embase, Web of Science, and the Cochrane Library, to collect all the relevant literature published since the establishment of the databases until July 30, 2024, and then screened to determine the qualified literature and extracted the relevant information. Finally, RevMan 5.4 software was utilized to conduct the meta-analysis for determining the 95% confidence interval (CI) and pooled risk ratio (RR). There were 9 study indicators, including the pathologic complete remission (pCR) rate, tumor downstaging rate, R0 resection rate, sphincter preservation rate, disease-free survival (DFS), overall survival (OS), acute ≥3 grade toxicity rate, surgery complication rate, and distant recurrence rate. When moderate, even severe, heterogeneity was found, a random-effect model was applied; otherwise, a fixed-effect model was used for the analysis.

Results

A total of 6 eligible RCTs and 2259 participants were included in this meta-analysis. Compared with the standard LCCRT, TNT treatment on the basis of SCRT/CCT increased the pCR rate significantly [RR = 1.67, 95% CI (1.36, 2.04), P < 0.00001], especially in ≥ 4 cycles of the CCT arm [RR = 1.77, 95% CI: (1.41-2.23), p < 0.00001], and led to a similar tumor downstaging rate [RR = 0.99, 95% CI (0.85, 1.15), P = 0.92]. Moreover, survival outcomes, distant recurrence rate, and surgical indicators were comparable between the two groups.

Conclusion

For LARC patients, the SCRT/CCT regimen not only has a higher pCR rate, equivalent OS, and comparable additional indicators versus standard LCCRT but also shortens the treatment time, costs less, and improves patients' adherence to the innovative anti-tumor therapy; hence, with the concept of acute toxicity control, it could be further widely and safely utilized, especially in resource-limited settings.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024600180.

Lymphopenia is an adverse prognostic factor in rectal adenocarcinoma patients receiving long-course chemoradiotherapy

PURPOSE

Neoadjuvant radiotherapy (RT) or chemoradiotherapy (CRT) is the standard treatment for locally advanced rectal adenocarcinoma. The recent emerging data on preoperative immunotherapy as an effective therapeutic modality for mismatch repair deficient rectal carcinomas suggests that the immune system plays a significant role in tumor eradication. Although RT has been shown to stimulate anti-tumor immunity, it also leads to substantial lymphopenia, hindering the effect of immune response.

MATERIALS AND METHODS

We retrospectively analyzed 33 rectal adenocarcinoma patients who underwent CRT in our department, aiming to identify the effects of CRT on the peripheral blood lymphocyte counts (LC) and the potential impact of CRT-induced lymphopenia on tumor response and prognosis of patients.

RESULTS

A statistically significant decrease in the LC of patients was observed after CRT (median values of 2,184/μL and 517/μL before and after treatment, respectively; p < 0.001). While no correlation between ypT-stage, ypN status, and LC was found, poor tumor regression grade was significantly associated with lower LC (p = 0.036). Moreover, lymphopenia was associated with poorer distant metastasis-free survival (p = 0.003). Distant metastases were documented in 0% of patients with post-CRT LC above 518/μL vs. 44.5% of patients with lower LC values.

CONCLUSION

Although further investigation is demanded, given the limited number of patients analyzed in the study, lymphopenia emerges as a significant adverse event that rectal adenocarcinoma patients face during treatment with neoadjuvant CRT, with subsequent implications on tumor response and prognosis. Protection of the immune system during CRT emerges as an important target for clinical research.

Significant Pathologic Response Following Neoadjuvant Therapy and Curative Resection in Patients With Rectal Cancer: Surgical and Oncological Outcomes From a Retrospective Cohort Study

AIM

This study evaluated surgical complication rates, recurrence-free survival, overall survival (OS), and stoma status of patients with rectal cancer after significant pathologic response following neoadjuvant treatment and curative resection. Pathologic complete response (pCR) and near-pCR patients constitute patients in our study.

METHODS

Included was a retrospective cohort study of patients with rectal cancer who were diagnosed between July 2011 and September 2022 and who underwent neoadjuvant therapy and surgical resection.

RESULTS

Of 696 patients with rectal cancer, 149 (21.4%) cases achieved significant pathologic response. During the 64 (70.5) months of follow-up, recurrence occurred in 16.1% of patients and distant metastases account for the majority of them. Age (p = 0.014) and receiving adjuvant chemotherapy (p = 0.016) were significantly related to the occurrence of recurrence. The five-year recurrence-free survival (RFS) and OS rates were obtained at 83% and 87%, respectively. Although age and surgical technique were significant factors in univariate Cox regression analysis, none of the candidate variables were significant prognostic factors for RFS in the multiple models. The risk of surgical complications remained in these patients. The most frequent complication attributed to infection (20.8%). Despite the 24.8% presence of permanent stoma at primary surgery, more than 50% of our patients lived without stoma at the last follow-up.

CONCLUSION

Our recurrence rate was about 16%, and it was related to age and adjuvant chemotherapy. These patients achieved over 80% rates of five-year RFS and OS. No significant prognostic factors were found on RFS in the multivariable model. As a matter of course, the risk of surgical complications and permanent stoma has still remained in these patients.

Physical activity at diagnosis is associated with tumor downstaging after neoadjuvant chemoradiotherapy in patients with rectal cancer

BACKGROUND

Patients with rectal cancer are often treated with neoadjuvant chemoradiotherapy, followed by a waiting period and surgical resection. Good or complete response to neoadjuvant chemoradiotherapy might enable organ preservation, which highlights the need to increase response rates. Pre-clinical studies suggest that physical activity during neoadjuvant chemoradiotherapy may improve tumor downstaging.

PURPOSE

To investigate whether physical activity and physical functioning of patients with rectal cancer at diagnosis are associated with tumor downstaging after neoadjuvant chemoradiotherapy.

MATERIALS AND METHODS

Patients were included if they participated in the Dutch Prospective ColoRectal Cancer Cohort, a nationwide cohort providing an infrastructure for scientific research, and received neoadjuvant chemoradiotherapy for rectal cancer. Tumor downstaging was dichotomized into good/complete or moderate/poor downstaging. Physical activity (total physical activity, moderate-to-vigorous physical activity (MVPA), and Dutch physical activity guideline adherence) and physical functioning were assessed using questionnaires. Logistic regression analyses were performed to examine associations of physical activity and physical functioning with tumor downstaging, adjusted for relevant confounders.

RESULTS

268 patients (aged 62 ± 11 years, 33 % female) with rectal cancer were included. Patients with moderate (OR = 2.07; 95%CI = 1.07 - 4.07; p = 0.03) or high (OR = 2.05; 95%CI = 1.05 - 4.07; p = 0.04) levels of MVPA were more likely to have good/complete tumor downstaging than patients with low levels. No significant associations with tumor downstaging were found for total physical activity, Dutch physical activity guideline adherence, and physical functioning.

CONCLUSIONS

We found augmented tumor downstaging in patients with rectal cancer with moderate or high levels of self-reported MVPA before the start of neoadjuvant chemoradiotherapy compared to patients with low levels.

Predictive value of flexible proctosigmoidoscopy and laboratory findings for complete clinical responses after neoadjuvant chemoradiotherapy in patients with locally advanced primary rectal cancer: a retrospective cohort study

PURPOSE

Colorectal cancer is the second leading cause of cancer death worldwide. Standard treatments for locally advanced rectal cancer include neoadjuvant chemoradiotherapy and total mesorectal excision (TME), which are associated with significant morbidity. After neoadjuvant therapy, one-third of patients achieve a pathological complete response (pCR) and are eligible for a watch-and-wait approach without TME. The purpose of this study was to determine the potential predictors of pCR before surgery.

METHODS

The demographic, clinical, and endoscopic data of 119 patients with primary locally advanced rectal cancer without distant metastasis who underwent restaging endoscopy and TME 6-8 weeks after the end of neoadjuvant therapy were collected. The absence of tumor cells in the histological examination of the TME specimen after neoadjuvant therapy was considered pCR. Binary logistic regression and receiver operating characteristic curves were utilized for analysis.

RESULTS

According to the multivariate logistic regression analysis, flattening of marginal tumor swelling (p value < 0.001, odds ratio = 100.605) emerged as an independent predictor of pCR in rectal cancer patients. Additionally, receiver operating characteristic curve analysis revealed that lower preoperative carcinoembryonic antigen and erythrocyte sedimentation rate levels predict pCR, with cutoffs of 2.15 ng/ml and 19.0 mm/h, respectively.

CONCLUSION

Carcinoembryonic antigen and erythrocyte sedimentation rate, along with the presence of flattening of marginal tumor swelling, can predict pCR after neoadjuvant chemoradiotherapy in patients with primary rectal cancer. These factors offer a potential method for selecting candidates for conservative treatment based on endoscopic and laboratory findings.

Assessment of Distinct Gut Microbiome Signatures in a Diverse Cohort of Patients Undergoing Definitive Treatment for Rectal Cancer

Introduction

Disparities in incidence and outcome of rectal cancer are multifactorial in etiology but may be due, in part, to differences in gut microbiome composition. We used serial robust statistical approaches to assess baseline gut microbiome composition in a diverse cohort of patients with rectal cancer receiving definitive treatment.

Methods

Microbiome composition was compared by age at diagnosis (< 50 vs ≥ 50 years), race and ethnicity (White Hispanic vs non-Hispanic), and response to therapy. Alpha diversity was assessed using the Shannon, Chao1, and Simpson diversity measures. Beta diversity was explored using both Bray-Curtis dissimilarity and Aitchison distance with principal coordinate analysis. To minimize false-positive findings, we used two distinct methods for differential abundance testing: LinDA and MaAsLin2 (all statistics two-sided, Benjamini-Hochberg corrected false discovery rate < 0.05).

Results

Among 64 patients (47% White Hispanic) with median age 51 years, beta diversity metrics showed significant clustering by race and ethnicity (p < 0.001 by both metrics) and by onset (Aitchison p = 0.022, Bray-Curtis p = 0.035). White Hispanic patients had enrichment of bacterial family Prevotellaceae (LinDA fold change 5.32, MaAsLin2 fold change 5.11, combined adjusted p = 0.0007). No significant differences in microbiome composition were associated with neoadjuvant therapy response.

Conclusion

We identified distinct gut microbiome signatures associated with race and ethnicity and age of onset in a diverse cohort of patients undergoing definitive treatment for rectal cancer.

Gross morphologic features of surgical specimen in rectal cancer patients with pathological complete response following neoadjuvant chemoradiotherapy: A cross-sectional study

BACKGROUND

pathological complete response (pCR) is achieved in 10%-30% of rectal cancer patients following neoadjuvant chemoradiotherapy and surgery. Residual mucosal abnormalities, which make patients ineligible for nonoperative management, may not be an accurate indicator of the pCR. The purpose of this study was to report the gross findings of rectal cancer patients with pathological complete responses.

METHODS

This study was conducted at Tehran University of Medical Sciences, Tehran, Iran. A total of 130 patients with rectal adenocarcinoma, treated by neoadjuvant chemoradiotherapy, followed by surgical resection between March 2007, and March 2017, with a surgical pathology report of pCR, were included. Patients' demographics and pretreatment tumor characteristics were collected from the medical records. Data regarding residual mucosal abnormalities were extracted from postoperative surgical pathology reports. Abnormal findings were reported as "ulcer" or " non-ulcerative lesion".

RESULTS

One hundred and fifteen patients (88.5%; 95% CI: 81.7%-93.4%) had at least one abnormal finding in the gross examination, including ulcer or non-ulcerative lesion (any mucosal abnormalities other than ulcers, including polyps, telangiectasia, etc.). Patients with higher-stage tumors had a higher chance of having an ulcerative lesion (p = 0.05). Younger patients tended to have deeper layers of involvement (p = 0.013). Patients with different gross findings were not significantly different regarding baseline characteristics, except for the pretreatment stage, where patients with a higher stage had higher odds of having ulcerative lesions.

CONCLUSIONS

Most rectal cancer patients achieving a pCR exhibit abnormalities on gross examination. The higher pretreatment stages were significantly associated with gross abnormalities especially ulcers.

Comparing outcomes and cost in surgery versus watch & wait surveillance of patients with rectal cancer post neoadjuvant long course chemoradiotherapy

BACKGROUND

Watch and wait (W&W) in complete clinical responders after neoadjuvant chemoradiotherapy has increasingly robust data supporting its oncological safety. Recently, studies have assessed the real-world costs of this strategy compared to surgical resection. Our aim was to compare our oncological safety and costs associated with operative and surveillance strategies to international literature.

METHODS

Data were retrospectively collected and analysed via electronic health records from March 2014 to March 2021 in Christchurch, New Zealand. Two cohorts were created based on intention to treat. All hospital events were recorded and costed, as well as oncologic outcomes. Our primary endpoints were the cumulative cost of both strategies, 3-year survival rate, and disease-free survival.

RESULTS

Forty-eight patients were identified who had rectal cancers resected (OT) with a yPT0N0 pathology, and 42 who were on the wait-and-watch (W&W) audit after having a clinical complete response. After exclusions, we identified 38 OT and 23 W&W patients; the W&W group were more co-morbid (P = 0.05), had worse functional status (P = 0.008), higher BMI (P = 0.34) and more favourable clinical tumour staging (P = 0.01). The operative treatment (OT) group (n = 38) had more acute admissions (34% versus 13% in W&W, P = 0.08, OR 0.29). There was a 35.7% (n = 8 of 23) local recurrence in W&W and none in the OT group (P ≤ 0.001), with successful salvage in the W&W with local recurrence in 71.5% (n = 5 of 7). Three-year distant metastasis-free rate was 97.3% in the OT group and 90.9% in W&W (p = 0.05). Overall survival was 100% (W&W) and 94.7% (OT); (P = 0.019). Care in the OT group cost more than W&W, accounting for local regrowth management; $NZ70,759.56 versus $NZ47,905.52 (P = 0.014).

CONCLUSION

This study found better oncological outcomes in the OT group, whilst the W&W group had reduced morbidity and acute bed days. The cost of wait and watch was approximately two-thirds that of operative treatment, even accounting for salvage procedures for local regrowth.

Does complete pathological response increase perioperative morbidity risk in rectal cancer?

AIM

The optimal management of patients with clinical complete response after neoadjuvant treatment for rectal cancer is controversial. The aim of this study is to compare the morbidity between patients with locally advanced rectal cancer who have had a pathological complete response (pCR) or not after neoadjuvant chemoradiotherapy (NCRT) and total mesorectal excision (TME). The study hypothesis was that pCR may impact the surgical complication rate.

METHOD

A retrospective cohort study was conducted of a prospectively maintained database in Australia and New Zealand, the Binational Colorectal Cancer Audit, that identified patients with locally advanced rectal cancer (<15 cm from anal verge) from 1 January 2007 to 31 December 2019. Patients were included if they had locally advanced rectal cancer and had undergone NCRT and proceeded to surgical resection.

RESULTS

There were 4584 patients who satisfied the inclusion criteria, 65% being male. The mean age was 63 years and 11% had a pCR (ypT0N0). TME with anastomosis was performed in 67.8% of patients, and the majority of the cohort received long-course radiotherapy (81.7%). Both major and minor complications were higher in the TME without anastomosis group (17.3% vs. 14.7% and 30.6% vs. 20.8%, respectively), and the 30-day mortality was 1.31%. In the TME with anastomosis group, pCR did not contribute to higher rates of surgical complications, but male gender (p < 0.0012), age (p < 0.0001), preoperative N stage (p = 0.0092) and American Society of Anesthesologists (ASA) score ≥3 (p < 0.0002) did. In addition, pCR had no significant effect (p = 0.44) but male gender (p = 0.0047) and interval to surgery (p = 0.015) contributed to higher rates of anastomotic leak. In the TME without anastomosis cohort, the only variable that contributed to higher rates of complications was ASA score ≥3 (p = 0.033).

CONCLUSION

Patients undergoing TME dissection for rectal cancer following NCRT showed no difference in complications whether they had achieved pCR or not.

"Long-term oncologic outcomes and risk factors for distant recurrence after pathologic complete response following neoadjuvant treatment for locally advanced rectal cancer. A nationwide, multicentre study"

BACKGROUND

Pathologic complete response (pCR) after multimodal treatment for locally advanced rectal cancer (LARC) is used as surrogate marker of success as it is assumed to correlate with improved oncologic outcome. However, long-term oncologic data are scarce.

METHODS

This retrospective, multicentre study updated the oncologic follow-up of prospectively collected data from the Spanish Rectal Cancer Project database. pCR was described as no evidence of tumour cells in the specimen. Endpoints were distant metastases-free survival (DMFS) and overall survival (OS). Multivariate regression analyses were run to identify factors associated with survival.

RESULTS

Overall, 32 different hospitals were involved, providing data on 815 patients with pCR. At a median follow-up of 73.4 (IQR 57.7-99.5) months, distant metastases occurred in 6.4% of patients. Abdominoperineal excision (APE) (HR 2.2, 95%CI 1.2-4.1, p = 0.008) and elevated CEA levels (HR = 1.9, 95% CI 1.0-3.7, p = 0.049) were independent risk factors for distant recurrence. Age (years) (HR 1.1; 95%-CI 1.05-41.09; p < 0.001) and ASA III-IV (HR = 2.0; 95%-CI 1.4-2.9; p < 0.001), were the only factors associated with OS. The estimated 12, 36 and 60-months DMFS rates were 96.9%, 91.3%, and 86.8%. The estimated 12, 36 and 60-months OS rates were 99.1%, 94.9% and 89.3%.

CONCLUSIONS

The incidence of metachronous distant metastases is low after pCR, with high rates of both DMFS and OS. The oncologic prognosis in LARC patients that achieve pCR after neoadjuvant chemo-radiotherapy is excellent in the long term.

Analysis of Survival in Complete Pathological Response after Long-Course Chemoradiotherapy in Patients with Advanced Rectal Cancer

BACKGROUND

Neoadjuvant chemoradiotherapy prior to surgery is the standard treatment for locally advanced rectal cancer. This consists in the patient's complete pathological response being achieved with no residual tumor presence in the resected specimen, which results in survival improvement.

METHODS

This retrospective study aimed to examine the rate of complete pathological response in patients with advanced rectal cancer treated with neoadjuvant long-course chemoradiotherapy and to examine the survival differences between the different tumor regression grade (TRG) scores.

RESULTS

A total of 154 patients were operated prior to long-course chemoradiotherapy with a total of 50 Gy plus FOLFOX protocol. Complete pathologic response was achieved in 29 (18.8%) patients. There was no statistical difference for the different pathologic responses according to gender, type of surgery, and number of harvested lymph nodes. Mean survival for all the groups was 37.2 months. Survival within a different TRG score exhibited statistical significance (p = 0.006). Overall, the survival rate during the follow-up period was of 81.8%.

CONCLUSIONS

The complete pathological response rate in this study was of 18.8%. High tumor regression grade scores (TRG0 and TRG1) had a survival rate of over 90% during follow-up. Multivariate analysis identified perineural invasion and tumor regression grade as independent factors that affect survival.

A Predictive Model to Evaluate Pathologic Complete Response in Rectal Adenocarcinoma

Introduction: Neoadjuvant chemo-radiotherapy (nCRT) before surgery was a standard treatment strategy for locally advanced rectal cancer (LARC). The aim of this study was to assess the relationship between the predictive factors and pathological complete response (pCR) in rectal cancer patients, especially in ultra-low ones. Method: A total of 402 patients were involved in this retrospective study. The logistic regression analyses were used to compare the different subgroups in univariate analysis. Multivariate analysis was performed to determine the independent predictive factors of pCR by using a logistic regression model. Results: A total of 402 patients received preoperative CRT. In all patients, multivariate analysis revealed that circumferential tumor extent rate (CER) (≤ 2/3cycle vs >2/3 cycle, P < .001, OR = 4.834, 95% CI: 2.309-10.121), carcinoembryonic antigen (CEA) level (both ≤ 5 vs pre > 5 and post ≤ 5 vs both > 5, P = .033, OR = 1.537, 95% CI: 1.035-2.281), and interval time between the end of CRT and surgery (P = .031, OR = 2.412, 95% CI: 1.086-5.358) were predictive factors for pCR. The area under the curve (AUC) of the predictive model was 0.709 (95% CI: 0.649-0.769), which was significantly higher than the CER (0.646, 95% CI: 0.584-0.709), interval time (0.563, 95% CI: 0.495-0.631) and CEA level (0.586, 95% CI: 0.518-0.655). In ultra-low rectal patients, multivariate logistic regression analysis revealed that CER (≤ 2/3 cycle vs > 2/3 cycle, P = .003, OR = 7.203, 95% CI: 1.934-26.823) and mismatch repair (MMR) status (pMMR vs dMMR, P = .016, OR = 0.173, 95% CI: 0.041-0.720) were predictive factors for pCR. The AUC of the predictive model was 0.653 (95% CI: 0.474-0.832). Conclusion: New predictive models were varied by the histologic types and MMR statuses to evaluate the trend of tumor response to nCRT in all RC cases and ultra-low RC patients, which may be used to individualize stratify for selected LARC patients.

Pathologic complete response after neoadjuvant chemotherapy/(re)chemoradiation for pelvic relapse of rectal cancer undergoing complex pelvic surgery: more frequent than expected?

PURPOSE

To estimate the rate of pathologic complete response (pCR) after neoadjuvant chemotherapy/(re)chemoradiation and its impact on survival in locally recurrent rectal cancer (LRRC) and to identify predictors of pCR or differences between neoadjuvant treatments.

METHODS

Among 394 LRRC patients treated at the National Cancer Institute of Milan (Italy), 74 (27.8%) were treated with neoadjuvant chemotherapy with or without (re)chemoradiation before surgery. The pCR rate was estimated, and its impact on 5-year survival was evaluated with the Kaplan-Meier survival method. Univariate analysis was performed to find pre-treatment predictors of pCR.

RESULTS

After surgery, in 12 (16.2%) patients, a pCR was observed. All patients who reached pCR had R0 margins after surgery; among the 62 non-pCR patients, R0 margins were obtained in 29 (46.8%) cases only (p = 0.0004). pCR patients showed a significantly higher 5-year overall survival compared to non-pCR cases (33.3% vs. 21.0%, p = 0.045) and a trend toward better 5-year re-local recurrence-free survival. On univariate analysis, no predictor of pCR was found in the present study based on pre-treatment features.

CONCLUSION

Since pCR is significantly associated to R0 resection and 5-year overall survival, pCR could be a target for LRRC cure. However, pCR is currently unpredictable based on pre-treatment features.

Neoadjuvant Short-Course Radiotherapy Followed by Consolidation Chemotherapy before Surgery for Treating Locally Advanced Rectal Cancer: A Systematic Review and Meta-Analysis

Neoadjuvant short course radiotherapy (SCRT) followed by consolidation chemotherapy (CCT) is an alternative treatment for locally advanced rectal cancer (LARC). We performed this systematic review and meta-analysis to explore the tumor response and oncological outcomes of this new approach compared to conventional chemoradiotherapy (CRT). An online search of the PubMed, Embase, and Cochrane Library databases was performed. This review included 7507 patients from 14 different cohorts. The pCR rate was higher with SCRT + CCT than that with CRT (RR: 1.60; 95% CI: 1.35−1.91; p < 0.01). SCRT + CCT provided a higher ypN0 response (RR: 1.06; 95% CI: 1.01−1.12; p = 0.02). There were no differences in R0 resection and positive CRM rates; however, more sphincter-preservation surgeries were performed in the SCRT + CCT arm (RR: 1.06; 95% CI: 1.01−1.11; p = 0.02). There was no difference in the OS and DFS between the SCRT + CCT and the CRT arms (OS: HR: 0.85, p = 0.07; DFS: HR: 0.88, p = 0.08). The compliance and toxicity were comparable between the SCRT and CRT groups. In the subgroup analysis, patients who underwent four or more cycles of CCT had better pCR and DFS events. Therefore, SCRT followed by consolidation chemotherapy might be an effective alternative treatment for LARC.

Can pretreatment platelet-to-lymphocyte and neutrophil-to-lymphocyte ratios predict long-term oncologic outcomes after preoperative chemoradiation followed by surgery for locally advanced rectal cancer?

Purpose

Systemic inflammation is associated with various malignancies, including colorectal cancer, as possible prognostic predictors. We aimed to evaluate the correlation of pretreatment the platelet-to-lymphocyte (PLR) and the neutrophil-to-lymphocyte (NLR) ratio with long-term oncologic outcomes and pathologic complete response (pCR) in locally ad vanced rectal cancer patients who received neoadjuvant concurrent chemoradiotherapy (CRT) followed by curative resection.

Methods

Between October 1996 and December 2015, 168 rectal cancer patients treated with preoperative CRT followed by surgery were enrolled. The set cut-off/mean PLR and NLR were 170 and 2.8. We analyzed the relationship between PLR, NLR, and the 5-year overall survival (OS), disease-free survival (DFS), and pCR rate.

Results

The 5-year OS rates were 75.9% and 59.8% in the highand low-PLR groups. The 5-year DFS rates were 62.9% and 50.8% in the high- and low-PLR groups, with no significant difference. In addition, the 5-year OS rates were 75.7% and 58.4%, and the 5-year DFS rates were 62.5% and 50.0% in the high- and low-NLR groups, respectively, both without any significant difference. Multivariate analysis showed only pretreatment PLR as an independent prognostic factor for OS (hazard ratio, 1.850; 95% confidence interval, 1.041–3.287; P=0.036), and both serologic markers were not independent prognostic factors for 5-year DFS.

Conclusion

Neither PLR nor NLR was associated with 5-year DFS nor pCR to neoadjuvant CRT. Only pretreatment PLR can be used in predicting OS in locally advanced rectal cancer patients who received neoadjuvant CRT followed by curative resection.

A Nomogram for Predicting Pathological Complete Response to Neoadjuvant Chemoradiotherapy Using Semiquantitative Parameters Derived From Sequential PET/CT in Locally Advanced Rectal Cancer

We evaluated the predictive value of semiquantitative volumetric parameters derived from sequential PET/CT and developed a nomogram to predict pathological complete response (pCR) in patients with rectal cancer treated by neoadjuvant chemoradiotherapy (nCRT). From April 2008 to December 2013, among the patients who underwent nCRT, those who were taken sequential PET/CT before and after nCRT were included. MRI-based staging and semiquantitative parameters of PET/CT including standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated before and after nCRT. Multivariable analysis was performed to select significant predictors to construct a nomogram. Sensitivity, specificity, accuracy, and area under the receiver operating characteristics curve (AUC) of the model were evaluated to determine its performance. Among 137 eligible patients, 17 (12.4%) had pCR. All post-PET/CT parameters showed significant differences between pCR and non-pCR groups. Patients were randomly assigned to a training group (91 patients) and a validation group (46 patients). In multivariable analysis with the training group, post-CEA, post-MRI T staging, post-SUV_max, and post-MTV were significantly associated with pCR. There was no significant pre-nCRT variable for predicting pCR. Using significant predictors, a nomogram was developed. Sensitivity, specificity, accuracy, and AUC of the nomogram were 0.882, 0.808, 0.848, and 0.884 with the training group and 0.857, 0.781, 0.783, and 0.828 with the validation group, respectively. This model showed the better performance than other predictive models that did not contain PET/CT parameters. A nomogram containing semiquantitative post-PET/CT could effectively select candidates for organ-sparing strategies.

Lincp21-RNA as Predictive Response Marker for Preoperative Chemoradiotherapy in Rectal Cancer

Preoperative chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer (RC) patients, but its use in non-responders can be associated with increased toxicities and resection delay. LincRNA-p21 is a long non-coding RNA involved in the p53 pathway and angiogenesis regulation. We aimed to study whether lincRNA-p21 expression levels can act as a predictive biomarker for neoadjuvant CRT response. We analyzed RNAs from pretreatment biopsies from 70 RC patients treated with preoperative CRT. Pathological response was classified according to the tumor regression grade (TRG) Dworak classification. LincRNA-p21 expression was determined by RTqPCR. The results showed that lincRNA-p21 was upregulated in stage III tumors (p = 0.007) and in tumors with the worst response regarding TRG (p = 0.027) and downstaging (p = 0.016). ROC curve analysis showed that lincRNA-p21 expression had the capacity to distinguish a complete response from others (AUC:0.696; p = 0.014). LincRNA-p21 was shown as an independent marker of preoperative CRT response (p = 0.047) and for time to relapse (TTR) (p = 0.048). In conclusion, lincRNA-p21 is a marker of advanced disease, worse response to neoadjuvant CRT, and shorter TTR in locally advanced RC patients. The study of lincRNA-p21 may be of value in the individualization of pre-operative CRT in RC.