The role of carcinoembriogenic antigen in predicting response and survival to neoadjuvant chemoradiotherapy for distal rectal cancer

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.

Prognostic value of nutrition and immune‑related biomarkers in patients with locally advanced rectal cancer treated with chemoradiotherapy

The ability of nutrition and immune-related biomarkers to predict outcomes in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant therapy followed by surgery remains controversial due to the lack of evidence regarding the accuracy and reliability of these biomarkers in predicting outcomes for such patients. Therefore, the present study aimed to investigate the prognostic potential of nutrition and immune-related biomarkers in patients with LARC who underwent chemoradiotherapy followed by curative surgery. The clinical data of patients with LARC treated with neoadjuvant therapy followed by surgery between January 2010 and December 2019 were analyzed. In total, 214 consecutive patients were enrolled into the present study, who were then categorized into low and high prognostic nutritional index (PNI) groups. The X-tile 3.6.1 program was used to calculate and then determine the optimal cut-off values for PNI. Disease-free survival (DFS) and overall survival (OS) were compared between the low and high PNI groups. Cox regression analysis demonstrated that low PNI and high post-chemoradiotherapy carcinoembryonic antigen levels were significantly associated with reduced disease-free survival and overall survival. Specifically, a low PNI was associated with inferior 5-year DFS (P=0.025) and OS (P=0.018). These findings suggest that amongst the nutritional and immune-related biomarkers, PNI is a significant predictive factor for disease recurrence and mortality in patients with LARC treated with neoadjuvant therapy followed by surgery.

Tumor response rates based on initial TNM stage and tumor size in locally advanced rectal cancer: a useful tool for shared decision-making

BACKGROUND

It is accepted that tumor stage and size can influence response to neoadjuvant therapy in locally advanced rectal cancer (LARC). Studies on organ preservation to date have included a wide variety of size and TNM stage tumors. The aim of this study was to report tumor response based on each relevant TNM stage and tumor size.

METHODS

Patients treated with LARC from 2014 to 2021 with cT2-3NxM0 tumors who received neoadjuvant chemoradiotherapy with or without induction chemotherapy were included. Tumors were staged and tumor size calculated on pelvic MRI at the time of diagnosis (cTNM). Tumor size was based on the largest dimension taken on the longest axis of each tumor. Clinical response was defined on the basis of post-treatment pelvic MRI and pathological response following surgery, when performed. Statistical analysis was performed using IBM SPSS Statistics™, version 20. Data from 432 patients were analyzed as follows: cT2N0 (n = 51), cT2N+ (n = 36), cT3N0 (n = 76), cT3N+ (n = 270).

RESULTS

The rate of complete or near-complete response (cCR or nCR) varied from 77% in cT2N0 ≤ 3 cm to 20% in cT3N+ > 4 cm. Organ preservation without recurrence at 2 years was achieved in 86% of patients with cT2N0, 50% in cT2N+, 39% in cT3N0, and 12% in cT3N+.

CONCLUSION

There is significant variation in tumor response according to tumor stage and size. Tumor response appears inversely proportional to increasing TNM stage and tumor size. This data can support both refinement of selective patient recruitment to organ preservation programs and shared decision-making.

Oncological risks associated with the planned watch-and-wait strategy using total neoadjuvant treatment for rectal cancer: A narrative review

Overall survival benefit of total neoadjuvant treatment (TNT) remains unconfirmed. Thus, in our opinion, the main rationale for using TNT is a planned watch-and-wait (w&w) strategy to improve patients' long-term quality of life through organ preservation. The OPRA randomized trial, which examined a planned w&w strategy using TNT, showed a higher organ preservation rate but also a higher regrowth rate compared to studies on the opportunistic w&w strategy. Higher rates of complete clinical response with TNT did not improve disease-free survival compared to historical controls. Therefore, the gain in organ-sparing capability might not be balanced by the increased oncological risk. The ultimate local failure rate in the intention-to-treat analysis of the OPRA trial was 13% for induction chemotherapy and 16% for consolidation chemotherapy, which seems higher than expected compared to 8% in a meta-analysis of w&w studies or 12% after TNT and surgery in the PRODIGE-23 and RAPIDO trials, which enrolled patients with more advanced cancers than the OPRA trial. Other studies also suggest worse local control when surgery is delayed for radio-chemoresistant cancers. Our review questions the safety of the planned w&w strategy using TNT in unselected patients. To reduce the oncological risk while maintaining high organ preservation rates, we suggest that the planned w&w strategy using TNT requires a two-tier patient selection process: before treatment and after tumor response assessment at the midpoint of consolidation chemotherapy. These robust selections should identify patients who are unlikely to achieve organ preservation with TNT and would be better managed by preoperative chemoradiotherapy (without consolidation chemotherapy) and surgery, or by discontinuing consolidation chemotherapy and proceeding directly to surgery.

Role of [18F]FDG-PET/CT in Evaluation of Tumor Response to Chemoradiation Therapy for Advanced Colorectal Cancer

Objectives

The objective is to evaluate the efficacy of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) computed tomography (CT) in the evaluation of tumor response to preoperative/palliative chemoradiotherapy (CRT) for advanced colorectal cancer; including metastatic cancer at primary presentation and recurrent cancers with local and/or distant metastasis.

Materials and Methods

Fifty patients with advanced rectal cancer underwent two point imaging with 18 FDG PET-CT before and after 3 weeks of completion of preoperative/palliative CRT in between 2016 and 2022. Patients with locally recurrent cancer also underwent radical surgery. The assessment consisted of the evaluation of the following metabolic PET parameters: Maximum standardized uptake value (SUVmax), SUVratio, metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Response was assessed among the followed patients using RECIST 1.1 criteria.

Observations and Results

There was a significant decline in the mean post therapy SUVmax and SUVratio as compared to baseline (P = 0.0001). Twenty-six out of 50 (52%) patients were classified as responders. A significant decrease in all parameters (SUVmax, SUVratio, TLG, and MTV) from baseline was observed in responders of the study when comparing with nonresponders (P < 0.05). Besides SUVmax and SUVratio, the mean posttherapy TLG was significantly reduced in responders than nonresponders (P = 0.0065).

Conclusion

PET-CT is a useful combined anatomic and functional imaging modality in monitoring tumor response to preoperative/palliative CRT in advanced rectal cancer, whether primary or recurrent, including metastatic cancers at presentation. Posttherapy SUV and TLG in particular are significantly associated with treatment response.

The Crying Need for a Better Response Assessment in Rectal Cancer

OPINION STATEMENT

Since total neoadjuvant treatment achieves almost 30% pathologic complete response, organ preservation has been increasingly debated for good responders after neoadjuvant treatment for patients diagnosed with rectal cancer. Two organ preservation strategies are available: a watch and wait strategy and a local excision strategy including patients with a near clinical complete response. A major issue is the selection of patients according to the initial tumor staging or the response assessment. Despite modern imaging improvement, identifying complete response remains challenging. A better selection could be possible by radiomics analyses, exploiting numerous image features to feed data characterization algorithms. The subsequent step is to include baseline and/or pre-therapeutic MRI, PET-CT, and CT radiomics added to the patients' clinicopathological data, inside machine learning (ML) prediction models, with predictive or prognostic purposes. These models could be further improved by the addition of new biomarkers such as circulating tumor biomarkers, molecular profiling, or pathological immune biomarkers.

Is It Really Gone? Assessing Response to Neoadjuvant Therapy in Rectal Cancer

PURPOSE

Non-operative management of rectal cancer is a feasible and appealing treatment option for patients who develop a complete response after neoadjuvant therapy. However, identifying patients who are complete responders is often a challenge. This review aims to present and discuss current evidence and recommendations regarding the assessment of treatment response in rectal cancer.

METHODS

A review of the current literature on rectal cancer restaging was performed. Studies included in this review explored the optimal interval between the end of neoadjuvant therapy and restaging, as well as modalities of assessment and their diagnostic performance.

RESULTS

The current standard for restaging rectal cancer is a multimodal assessment with the digital rectal examination, endoscopy, and T2-weighted MRI with diffusion-weighted imaging. Other diagnostic procedures under investigation are PET/MRI, radiomics, confocal laser endomicroscopy, artificial intelligence-assisted endoscopy, cell-free DNA, and prediction models incorporating one or more of the above-mentioned exams.

CONCLUSION

Non-operative management of rectal cancer requires a multidisciplinary approach. Understanding of the robustness and limitations of each exam is critical to inform patient selection for that treatment strategy.

Prognostic impact of conversion hepatectomy for initially unresectable colorectal liver metastasis

PURPOSE

This study aimed to evaluate the prognostic impact of conversion hepatectomy in patients with initially unresectable colorectal liver metastasis (CRLM) and to identify prognostic factors after conversion hepatectomy.

METHODS

Correlations of conversion hepatectomy with relapse-free survival (RFS) and overall survival (OS) were retrospectively investigated in 554 consecutive patients who underwent hepatectomy for CRLM in 2000-2017. Prognostic factors after conversion hepatectomy were examined in multivariable analysis.

RESULTS

Five hundred and nine patients (92%) had initially resectable CRLM at diagnosis and underwent hepatectomy (primary resection group) and 45 (8%) underwent conversion hepatectomy following chemotherapy (conversion group). The 5-year RFS was 30.0% in the primary resection group and 19.8% in the conversion group (p = 0.042); the respective 5-year OS rates were 62.0% and 52.4% (p = 0.253). Multivariable analysis did not identify conversion hepatectomy as a significant prognostic factor for RFS (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.64-1.37, p = 0.796) or OS (HR 1.12, 95% CI 0.67-1.79, p = 0.667). In the conversion group, multivariable analysis identified the following independent prognostic factors: timing of liver metastases for RFS (synchronous: HR 3.14, 95% CI 1.20-8.24, p = 0.020) and preoperative CEA level for RFS (> 5 ng/ml: HR 3.10, 95% CI 1.45-6.61, p = 0.003) and OS (> 5 ng/ml: HR 3.29, 95% CI 1.18-9.17, p = 0.023).

CONCLUSIONS

RFS and OS rates after conversion hepatectomy were not inferior to those after primary resection in patients with CRLM. Patients with a normal CEA level before hepatectomy can be expected to have good long-term prognosis after conversion hepatectomy.

Circulating Biomarkers in Predicting Pathological Response to Neoadjuvant Therapy for Colorectal Cancer

Circulating biomarkers show promise in the management of many cancers. They have become the novel non-invasive approach to complement the current strategies in colorectal cancer (CRC) management. Their ability in guiding diagnosis, evaluating response to treatment, screening and prognosis is phenomenal, especially when it comes to their minimally invasive nature. These “liquid biopsies,” which show potential for replacing invasive surgical biopsies, provide useful information on the primary and metastatic disease by providing an insight into cancer biology. Analysis of blood and body fluids for circulating tumour DNA (ctDNA), carcinoembryonic antigen (CEA), circulating tumour cells (CTC), or circulating micro RNA (miRNA) shows potential for improving CRC management. Recognizing a predictive model to assess response to neoadjuvant chemotherapy would help in better patient selection. This review was conducted with the aim of outlining the use of circulatory biomarkers in current practice and their effectiveness in the management of patients having CRC with a focus on response to neoadjuvant therapy.

Biomarkers of Favorable vs. Unfavorable Responses in Locally Advanced Rectal Cancer Patients Receiving Neoadjuvant Concurrent Chemoradiotherapy

Colorectal cancer is the second leading cause of cancer death globally. The gold standard for locally advanced rectal cancer (LARC) nowadays is preoperative concurrent chemoradiation (CCRT). Approximately three quarters of LARC patients do not achieve pathological complete response and hence suffer from relapse, metastases and inevitable death. The exploration of trustworthy and timely biomarkers for CCRT response is urgently called for. This review focused upon a broad spectrum of biomarkers, including circulating tumor cells, DNA, RNA, oncogenes, tumor suppressor genes, epigenetics, impaired DNA mismatch repair, patient-derived xenografts, in vitro tumor organoids, immunity and microbiomes. Utilizing proper biomarkers can assist in categorizing appropriate patients by the most efficient treatment modality with the best outcome and accompanied by minimal side effects. The purpose of this review is to inspect and analyze accessible data in order to fully realize the promise of precision oncology for rectal cancer patients.

The "Immunoscore" in rectal cancer: could we search quality beyond quantity of life?

Because of the function and anatomical environment of the rectum, therapeutic strategies for local advanced rectal cancer (LARC) must deal with two challenging stressors that are a high-risk of local and distal recurrences and a high-risk of poor quality of life (QoL). Over the last three decades, advances in screening tests, therapies, and combined-modality treatment options and strategies have improved the prognosis of patients with LARC. However, owing to the heterogeneous nature of LARC and genetic status, the patient may not respond to a specific therapy and may be at increased risk of side-effects without the life-prolonging benefit. Indeed, each therapy can cause its own side-effects, which may worsen by a combination of treatments resulting in long-term poor QoL. In LARC, QoL has become even more essential with the increasing incidence of rectal cancer in young individuals. Herein, we analyzed the value of the Immunoscore-Biopsy (performed on tumor biopsy at diagnosis) in predicting outcomes, alone or in association with clinical and imaging data, for each therapy used in LARC.

Current State of Neoadjuvant Radiotherapy for Rectal Cancer

Colorectal cancer is the third most commonly diagnosed cancer, with rectal cancer accounting for 30% of cases. The current standard of care curative treatment for locally advanced rectal cancer is (chemo)radiotherapy followed by surgery and adjuvant chemotherapy. Although neoadjuvant radiotherapy has reduced the risk of local recurrence to less than 10%, the risk of distant metastasis remained high at 30% affecting patient survival. In addition, there is a recognition that there is heterogeneity in tumor biology and treatment response with good responders potentially suitable for treatment de-escalation. Therefore, new treatment sequencing and regimens were investigated. Here, we reviewed the evidence for current neoadjuvant treatment options in patients with locally advanced rectal adenocarcinoma, and highlight the new challenges in this new treatment landscape.

Prognostic significance of carcinoembryonic antigen combined with carbohydrate antigen 19-9 following neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer

AIM

The clinical significance of carcinoembryonic antigen (CEA) combined with carbohydrate antigen 19-9 (CA19-9) in patients with rectal cancer is not well established. The aim of this study was to determine the prognostic value of these combined tumour markers in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT).

METHOD

A total of 687 consecutive patients with LARC who underwent nCRT and radical surgery were analysed. Tumour characteristics, recurrence-free survival (RFS) and overall survival (OS) were compared according to the number of elevated tumour markers measured before and after nCRT. In addition, the prognostic significance of perioperative changes in the combined tumour markers was further evaluated.

RESULT

The RFS and OS rates decreased in a stepwise manner in association with the number of elevated pre- and post-nCRT tumour markers (all p < 0.05). Multivariate analysis showed that only the number of elevated post-nCRT tumour markers was an independent prognostic factor (both p < 0.05). For 311 patients with elevated pre-nCRT tumour markers, normalization of the tumour markers after nCRT was an independent prognostic protective factor (both p < 0.05), and patients with both markers elevated post-nCRT had a 2.5- and 3.7-fold increased risk of recurrence and death, respectively (p < 0.05). Furthermore, normalization of post-nCRT tumour markers after surgery was also closely related to an improved prognosis.

CONCLUSION

This combination of post-nCRT tumour markers can accurately predict the long-term survival of patients with LARC treated with nCRT and curative resection, and normalization of the combined tumour markers after either nCRT or surgery was associated with better survival.

Biomarkers and cell-based models to predict the outcome of neoadjuvant therapy for rectal cancer patients

Rectal cancer constitutes approximately one-third of all colorectal cancers and contributes to considerable mortality globally. In contrast to colon cancer, the standard treatment for localized rectal cancer often involves neoadjuvant chemoradiotherapy. Tumour response rates to treatment show substantial inter-patient heterogeneity, indicating a need for treatment stratification. Consequently researchers have attempted to establish new means for predicting tumour response in order to assist in treatment decisions. In this review we have summarized published findings regarding potential biomarkers to predict neoadjuvant treatment response for rectal cancer tumours. In addition, we describe cell-based models that can be utilized both for treatment prediction and for studying the complex mechanisms involved.

Prognostic Impact of Carcinoembryonic Antigen Levels in Rectal Cancer Patients Who Had Received Neoadjuvant Chemoradiotherapy

PURPOSE

Carcinoembryonic antigen (CEA) is a useful marker for rectal cancer. The aim of this study was to investigate the prognostic impact of CEA level according to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer patients who underwent radical surgery.

METHODS

A total of 245 patients with rectal cancer who underwent radical surgery were retrospectively evaluated. Serum CEA level was measured preoperatively and postoperatively. We compared survival outcomes based on CEA level before and after surgery according to nCRT.

RESULTS

Of the 245 patients, elevation of CEA level was observed preoperatively in 79 and postoperatively in 30, respectively. Eighty-seven (35.5%) patients received nCRT, and elevated CEA level was a significant prognostic factor both before and after surgery. In patients who had not received nCRT, an elevated CEA level was a significant prognostic factor before surgery but was not significant after surgery. In a multivariate analysis for prognostic factors, elevation of preoperative CEA level was an independent prognostic factor of disease-free survival (DFS) regardless of nCRT. Postoperative CEA level was an independent prognostic factor of DFS in patients who had received nCRT but was not a factor in patients who had not received nCRT.

CONCLUSION

Serum CEA level was an independent prognostic factor both preoperatively and postoperatively in rectal cancer patients who had received nCRT.

Prognostic Impact of Pretreatment Elevated and Normalized Carcinoembryonic Antigen Levels After Neoadjuvant Chemoradiotherapy in Resected Locally Advanced Rectal Cancer Patients

Purpose

The prognostic significance of pretreatment elevated and normalized CEA after neoadjuvant chemoradiotherapy (nCRT) was evaluated.

Materials and Methods

The characteristics of 951 locally advanced rectal cancer patients with nCRT were retrieved and were analyzed retrospectively. Pretreatment CEA levels were defined as CEA evaluated one week prior to the nCRT. CEA after nCRT was deemed as CEA measured one week before surgery. The normal CEA levels were set at <5 ng/mL. The normal CEA group was defined as patients with normal pretreatment CEA levels. The normalized CEA group was defined as patients with elevated pretreatment CEA levels and normal CEA levels after nCRT. The elevated CEA group was defined as patients with elevated pretreatment CEA levels and elevated CEA levels after nCRT.

Results

Compared with the elevated CEA group, the normalized CEA group was associated with better overall survival (OS) (HR: 0.625, 95%CI: 0.416-0.938, P=0.022). There was no difference between the normalized CEA group and the normal CEA group (HR: 1.143, 95%CI: 0.84-1.557, P=0.395).

Conclusion

In conclusion, the study indicated that OS of the normalized CEA group and the normal CEA group was better than the elevated CEA group.

High CFP score indicates poor prognosis and chemoradiotherapy response in LARC patients

BACKGROUND

Preoperative tumor markers, inflammation, and nutritional status are considered important predictors of prognosis and tumor response in locally advanced rectal cancer (LARC) patients. This study aims to explore the prognostic and predictive role of carcinoembryonic antigen (CEA), the Fibrinogen-Albumin Ratio Index (FARI), the Prognostic Nutritional Index (PNI) in LARC patients and compared them with a novel combined CEA-FARI-PNI (CFP) scoring system.

METHODS

A total of 138 LARC patients undergoing radical surgery following neoadjuvant chemoradiotherapy (NCRT) between January 2012 and March 2019 were enrolled. The X-tile program was used to determine the optimal cut-off values of CEA, FARI, and PNI, and CFP scoring system was constructed accordingly. The prognostic ability of these factors was assessed by the time-dependent receiver operating characteristic (ROC) curve, Kaplan-Meier, Cox regression, and logistic regression. Nomogram was established to evaluate the predictive role of these factors in tumor response.

RESULTS

The optimal cut-off values of CEA, FARI, and PNI were 5.15 ng/l, 10.56%, and 42.25 g/L, respectively. The time-dependent ROC curve showed that compared to CEA, FARI, and PNI, CFP showed stable predictive efficacy for overall survival (OS) and disease-free survival (DFS). In multivariate analysis, CFP was the only factor that could independently predict OS (HR = 8.117, p = 0.001) and DFS (HR = 4.994, p < 0.001). Moreover, high CFP (OR = 3.693, p = 0.002) was also an independent risk factor of poor response. The area under the ROC curve (AUC) of the nomograms for predicting tumor response was better including CFP (0.717) than without CFP (0.656) (p < 0.05).

CONCLUSIONS

The CFP score was a more reliable marker for predicting OS, DFS, and NCRT efficacy in LARC patients, and the score could apparently improve predicted efficacy of the nomogram.

The carcinoembryonic antigen ratio is a potential predictor of survival in recurrent colorectal cancer

BACKGROUND

The carcinoembryonic antigen (CEA) "value" itself is often useless in patients with a normal CEA level at initial presentation and those with tumor-irrelevant elevated CEA. Although the unified marker using CEA has been desirable for recurrent tumor staging as well as for primary tumor staging, little is known concerning its relationship with the survival of patients with recurrent colorectal cancer in particular.

METHODS

This retrospective historical study included patients who experienced disease relapse after curative surgery for stage I-III colorectal cancer between 2006 and 2018. A total of 129 patients with recurrent disease after curative surgery for colorectal cancer were included. We focused on the CEA "ratio" (CEA-R: the ratio of the CEA level at the time of recurrence to that measured 3 months before recurrence) and aimed to evaluate the correlation between CEA-R and survival in recurrent colorectal cancer.

RESULTS

Patients with a high CEA-R (≥ 2) exhibited significantly worse 2 year survival than those with a low CEA-R (< 2) (88.1% vs. 44.9%, P < 0.001), irrespective of the CEA value before primary resection. Multivariate analyses demonstrated that the CEA-R (HR; 3.270, 95% CI 1.646-6.497, P = 0.001) was a significant prognostic factor.

CONCLUSION

The CEA-R is a potential marker stratifying the survival of patients with disease relapse who exhibit aggressive biology at recurrent disease foci. As a novel marker, the CEA-R would serve as a clinical guide for tailoring treatment strategies at the time of disease relapse in patients with colorectal cancer.

Prognostic factors in patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy and radical resection of rectal cancer

BACKGROUND

There are only a few studies on the prognosis of patients with complete response of the tumour (ypT0) after neoadjuvant chemoradiotherapy (NCRT) and radical resection of rectal cancer. The aim of the study was to identify prognostic factors with regard to oncological outcome in ypT0 patients after NCRT and radical resection.

METHODS

All ypT0 patients with rectal cancer after NCRT and radical resection between January 2010 and June 2019 were included. Cox univariate and multivariate regression analyses were used to determine the prognostic factors of these patients.

RESULTS

Seventy-six patients with ypT0 rectal cancer were included. In nine patients (11.8%), lymph node metastasis was identified. Age, gender, elevated carcinoembryonic antigen (CEA) and ypN+ were risk factors associated with a worse 5-year disease-free survival (DFS) rate in univariate analysis (P = 0.08, 0.14, 0.007 and 0.003, respectively). In multivariate analysis, ypN+ and elevated CEA before NCRT were independent risk factors for worse 5-year DFS (P = 0.005 and 0.021, respectively). Elevated CEA before NCRT, post-operative chemotherapy and ypN+ were risk factors associated with worse overall survival in univariate analysis (P = 0.14, 0.002 and 0.17, respectively). However, in multivariate analysis, none of these three factors were independent risk factors for worse overall survival (P = 0.20, 0.34 and 0.06, respectively).

CONCLUSION

ypN+ and elevated CEA before NCRT were found to be independent risk factors for an unfavourable DFS in ypT0 patients with complete response of the tumour after neoadjuvant chemoradiotherapy for rectal cancer.

Diagnostic performances of leucine-rich α-2-glycoprotein 1 and stem cell factor for diagnosis and follow-up of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the most frequently diagnosed tumors worldwide with high mortality and morbidity. There is an urgent need for biomarkers to improve the outcomes and early detection of CRC. The sensitivity of traditional CRC tumor markers (carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9)) is not ideal. The levels of leucine-rich-alpha-2-glycoprotein 1 (LRG1) and stem cell factor (SCF) were evaluated, but the combined value of both markers is unclear. This case-control study included four groups: CRC patients before treatments (n = 22), CRC patients after treatments (n = 26), 20 patients with benign tumor, and 20 healthy subjects. Levels of routine biochemical and hematological markers, traditional tumor markers (CA19.9 and CEA), and candidate markers (LRG1 and SCF) were determined. Univariate and multivariate logistic regression analysis and area receiver-operating characteristic analysis (ROC) were used for evaluation the diagnostic performances of single and combined markers.

RESULTS

No significance difference in traditional tumor markers CEA, CA 19.9, and neutrophil-lymphocyte ratio (NLR) were found among study groups. SCF, LRG1, and platelet-lymphocyte ratio (PLR) were significantly decreased (p < 0.05) in non-treated CRC patients than after treated CRC. The combination between SCF and LRG1 showed highly significant difference in CRC patients compared with benign, healthy subjects, and among CRC groups (treated and non-treated) (p < 0.0001). The highest areas under curve (AUCs) were observed when LRG1 was used as a single predictor for discriminating CRC from healthy (0.87), benign (0.84), and non-treated CRC vs treated CRC (0.82). AUCs were jumped to 0.90, 0.84, and 0.84 when LRG1 and SCF were combined.

CONCLUSION

Our study revealed that LRG1 and SCF were potential diagnostic and follow-up markers for CRC.

Prognostic value of changes in serum carcinoembryonic antigen levels for preoperative chemoradiotherapy response in locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiotherapy (CRT) is a standard treatment modality for locally advanced rectal cancer. However, CRT alone cannot improve overall survival. Approximately 20% of patients with CRT-resistant tumors show disease progression. Therefore, predictive factors for treatment response are needed to identify patients who will benefit from CRT. We theorized that the prognosis may vary if patients are classified according to pre- to post-CRT changes in carcinoembryonic antigen (CEA) levels.

AIM

To identify patients with locally advanced rectal cancer for preoperative chemoradiotherapy based on carcinoembryonic antigen levels.

METHODS

We retrospectively included locally advanced rectal cancer patients who underwent preoperative CRT and curative resection between 2011 and 2017. Patients were assigned to groups A, B, and C based on pre- and post-CRT serum CEA levels: Both > 5; pre > 5 and post ≤ 5; and both ≤ 5 ng/mL, respectively. We compared the response to CRT based on changes in serum CEA levels. Receiver operating characteristic curve analysis was performed to determine optimal cutoff for neutrophil–lymphocyte ratio and platelet–lymphocyte ratio. Multivariate logistic regression analysis was used to evaluate the prognostic factors for pathologic complete response (pCR)/good response.

RESULTS

The cohort comprised 145 patients; of them, 27, 43, and 65 belonged to groups A, B, and C, respectively, according to changes in serum CEA levels before and after CRT. Pre- (P < 0.001) and post-CRT (P < 0.001) CEA levels and the ratio of down-staging (P = 0.013) were higher in Groups B and C than in Group A. The ratio of pathologic tumor regression grade 0/1 significantly differed among the groups (P = 0.003). Group C had the highest number of patients showing pCR (P < 0.001). Most patients with pCR showed pre- and post-CRT CEA levels < 5 ng/mL (P < 0.001, P = 0.008). Pre- and post-CRT CEA levels were important risk factors for pCR (OR = 18.71; 95%CI: 4.62–129.51, P < 0.001) and good response (OR = 5.07; 95%CI: 1.92–14.83, P = 0.002), respectively. Pre-CRT neutrophil–lymphocyte ratio and post-CRT T ≥ 3 stage were also prognostic factors for pCR or good response.

CONCLUSION

Pre- and post-CRT CEA levels, as well as change in CEA levels, were prognostic markers for treatment response to CRT and may facilitate treatment individualization for rectal cancer.

Nonsurgical Management of Rectal Cancer

Neoadjuvant chemoradiotherapy followed by surgical resection is the standard of care for locally advanced rectal adenocarcinoma. Up to one third of patients achieve pathologic complete response (CR) with neoadjuvant therapy. Promising disease-free and overall survival outcomes have been reported in patients who achieve clinical CR after neoadjuvant therapy without surgical resection. Furthermore, patients who have local recurrence have acceptable disease control outcomes with salvage resection. With consideration of morbidities associated with surgical resection and similar clinical outcomes, interest in nonsurgical management of low rectal cancers has emerged. Randomized clinical trials are being conducted to evaluate a nonsurgical approach in rectal cancer. Lack of consensus on the definition of clinical CR, molecular biomarkers, and standardized nonsurgical management protocols is a significant barrier for routine clinical implementation of a nonsurgical management approach. This article aims to provide a concise review of the clinical experience and practical approach to the nonsurgical management of locoregional rectal adenocarcinoma.

Surgical treatment following neoadjuvant chemoradiotherapy in locally advanced rectal cancer

Colorectal cancer is a major public health problem worldwide, and locally advanced rectal cancer (LARC) is known for its poor prognosis. A multimodal treatment approach is the only method to achieve satisfactory local recurrence and survival rates in LARC. Determining which therapeutic modality for LARC has the most satisfactory influence on quality of life and disease outcome is still controversial. LARC treatment is subject to continuous advancement due to the development of new and better diagnostic tools, radiotherapy techniques, and chemotherapeutic agents. Herein, we review various therapeutic modalities for LARC from several aspects. In addition to radiotherapy techniques such as neoadjuvant chemoradiotherapy (NCRT), we discuss the progress of chemotherapy, appropriate time interval between NCRT and surgery, relationship between tumor location and NCRT efficacy/safety, wait-and-watch policy, and predictors of treatment response following NCRT. Because of the controversies and unanswered questions regarding NCRT treatments for LARC, additional investigations are required to determine which therapeutic approach is the most feasible for LARC patients.

Predictors of Early Distant Relapse in Rectal Cancer Patients Submitted to Preoperative Chemoradiotherapy

BACKGROUND

Neoadjuvant chemoradiotherapy (CRT) is a standard treatment for locally advanced rectal cancer. CRT leads to a better local control; however, this does not translate into a survival benefit. Long-term survival is mostly affected by the development of distant metastases after surgery. This study aimed to evaluate predictive clinical factors for the development of early metastatic disease after CRT.

METHODS

Clinical data of patients with stage II/III rectal cancer submitted to CRT between January 2000 and October 2014 were collected from prospectively maintained electronic databases of three Italian institutes. Patients were divided into two groups: those who developed metastasis within 12 months from surgical resection (Group A) and patients without or with late distant relapse (Group B).

RESULTS

Among 635 patients, 86 (13.5%) had early distant relapse within 1 year from surgery (Group A), and 549 (86.5%) did not (Group B). A higher rate of early distant relapse was associated with CEA levels above 3 ng/dL (20% vs. 10%; p <0.001), tumor lying under 5 cm from anal verge (20% vs. 9%; p <0.001), and age under 63 years (17% vs. 11%; p = 0.036). Multivariate analysis confirmed these factors to be independently correlated with a higher risk of early metastasis.

CONCLUSIONS

Younger age, low tumors, and high serum CEA may be associated with unfavorable early oncological outcomes after CRT and surgery for rectal cancer. These clinical factors could be useful to select patients for more aggressive therapeutic strategies.

Prognostic impact of preoperatively elevated and postoperatively normalized carcinoembryonic antigen levels following curative resection of stage I-III rectal cancer

BACKGROUND

Preoperative and early postoperative serum carcinoembryonic antigen (CEA) levels are known prognostic factors in rectal cancer. Recently, a large-scale study on colon cancer revealed that "preoperatively elevated and postoperatively normalized CEA levels" is not an indicator of poor prognosis. However, whether this hold true in rectal cancer patients is unknown. This study aimed to investigate the prognostic significance of preoperatively elevated and postoperatively normalized CEA levels in rectal cancer patients undergoing curative resection.

METHODS

Subjects were consecutive stage I-III rectal cancer patients who underwent curative resection without preoperative treatment at National Cancer Center Hospital between 2000 and 2015. Overall survival (OS) and the hazard function of recurrence or death were analyzed according to the CEA levels, as follows: normal preoperative CEA (normal group), preoperatively elevated but postoperatively normalized CEA (normalized group), and preoperatively and postoperatively elevated CEA (elevated group).

RESULTS

The normalized group (n =235) had worse OS (HR 1.49, 95% CI 1.08-2.04; P = .0142) compared to the normal group (n = 1208), and better OS compared to the elevated group (n = 47) (HR 0.53, 95% CI 0.31-0.91; P = .0208). The elevated group had the highest and earliest peak in hazard function, followed by the normalized group and the normal group, with median times to recurrence of 8.8, 15.5, and 18.5 months, respectively (P = .0223).

CONCLUSIONS

Prognosis after resection of rectal cancer was worse in patients with preoperatively elevated and postoperatively normalized CEA compared to those with normal preoperative CEA. Patients with elevated preoperative CEA might require intensive follow-up even if levels normalize after resection, especially in earlier periods, for early detection of recurrence.

A Review of the Role of Carcinoembryonic Antigen in Clinical Practice

Carcinoembryonic antigen (CEA) is not normally produced in significant quantities after birth but is elevated in colorectal cancer. The aim of this review was to define the current role of CEA and how best to investigate patients with elevated CEA levels. A systematic review of CEA was performed, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified from PubMed, Cochrane library, and controlled trials registers. We identified 2,712 papers of which 34 were relevant. Analysis of these papers found higher preoperative CEA levels were associated with advanced or metastatic disease and thus poorer prognosis. Postoperatively, failure of CEA to return to normal was found to be indicative of residual or recurrent disease. However, measurement of CEA levels alone was not sufficient to improve survival rates. Two algorithms are proposed to guide investigation of patients with elevated CEA: one for patients with elevated CEA after CRC resection, and another for patients with de novo elevated CEA. CEA measurement has an important role in the investigation, management and follow-up of patients with colorectal cancer.

Circulating cell-free DNA as predictor of treatment failure after neoadjuvant chemo-radiotherapy before surgery in patients with locally advanced rectal cancer

Background

Treatment of patients with locally advanced rectal cancer (LARC) is based on a combination of chemo-radiotherapy (CRT) and surgery. The rate of distant recurrences remains over 25%. Circulating cell-free DNA (cfDNA) in plasma is a mixture of normal and cancer-specific DNA segments and is a promising biomarker in patients with colorectal cancer. The aim of our study was to investigate plasma cfDNA as a prognostic marker for outcome in patients with LARC treated with neoadjuvant CRT and surgery.

Patients and methods

In total, 123 patients with LARC were included in 2 biomarker studies. Patients were treated with neoadjuvant CRT before TME surgery. Fifty-two (42%) of the patients received induction chemotherapy with capecitabine + oxaliplatin. Total cfDNA was measured by direct fluorescent assay in EDTA plasma samples obtained at baseline, after induction chemotherapy, and after CRT. Serial samples 5 years after surgery were collected in 51 patients (41%).

Results

Median follow-up was 55 months. Distant or local recurrence was seen in 30.9% of the patients. Patients with baseline cfDNA levels above the 75th quartile had a higher risk of local or distant recurrence and shorter time to recurrence compared with patients with plasma cfDNA below the 75th percentile (HR = 2.48, 95% CI: 1.3-4.8, P = 0.007). The same applied to disease-free survival (DFS) (HR = 2.43, 95% CI: 1.27-4.7, P = 0.015). In multivariate analysis, a high cfDNA level was significantly associated with time to progression and DFS. During follow-up, the association remained significant regardless of time point for sample analysis.

Conclusion

We have demonstrated an association between a high baseline plasma level of cfDNA and increased risk of recurrence, shorter time to recurrence, and shorter DFS in patients with LARC. Consequently, cfDNA could potentially improve pre- and post-treatment risk assessment and facilitate individualized therapy for patients with LARC.

CEA clearance pattern as a predictor of tumor response to neoadjuvant treatment in rectal cancer: a post-hoc analysis of FOWARC trial

BACKGROUND

The clinical factors that accurately predict the response to preoperative treatment in rectal cancer were yet unknown. The carcinoembryonic antigen (CEA) clearance pattern during neoadjuvant treatment has been developed and the predictive value explored in rectal cancer patients with elevated CEA levels (> 5 ng/mL).

METHODS

The training cohort was derived from the FOWARC prospective phase III trial, and 71/483 eligible patients were included. The validation cohort consisted of 75/587 consecutive rectal cancer patients from Xiangya Hospital between 2014 and 2015. The kinetic changes in serum CEA were measured at different time points during the neoadjuvant treatment. An exponential trend line was drawn using the CEA values. The patients were categorized into two groups based on the R² value of the trend line, which indicates the correlation coefficient between the exponential graph and measured CEA values: exponential decrease group (0.9 < R² ≤ 1.0) and non-exponential decrease group (R² ≤ 0.9).

RESULTS

In multivariate analysis, the patients in the CEA exponential decrease group had significantly high adequate rate of downstaging (ypT0-2N0M0), and pathologic complete response (pCR) rates after neoadjuvant treatment in the training cohort. The predictive values of the CEA clearance pattern for tumor downstaging and pCR were further confirmed in an independent validation cohort.

CONCLUSIONS

The CEA clearance pattern was an independent predictor of tumor response to neoadjuvant treatment in patients with rectal cancer. It might serve as an adjunct in the assessment of complete clinical response and guide individualized treatment strategies.

TRIAL REGISTRATION

NCT01211210.

Prognostic Role of Carcinoembryonic Antigen Level after Preoperative Chemoradiotherapy in Patients with Rectal Cancer

BACKGROUND

The prognostic role of post-chemoradiotherapy (CRT) carcinoembryonic antigen (CEA) level is not clear. We evaluated the prognostic significance of post-CRT CEA level in patients with rectal cancer after preoperative CRT.

METHODS

We reviewed 659 consecutive patients who underwent preoperative CRT and total mesorectal excision for non-metastatic rectal cancer. Patients were categorized into two groups according to post-CRT serum CEA level: low CEA (< 5 ng/mL) and high CEA (≥ 5 ng/mL).

RESULTS

Median post-CRT CEA level was 1.7 ng/mL (range, 0.1-207.0). A high post-CRT level was significantly associated with ypStage, ypT category, tumor regression grade, and pre-CRT CEA level. The 5-year overall survival rate of the 659 patients was 87.8% with a median follow-up period of 57.0 months (range, 1.4-176.4). When the post-CRT CEA groups were divided into groups according to pre-CRT CEA level, the 5-year overall survival rates were significantly different (P < 0.001 and P = 0.001, respectively). Post-CRT CEA level was an independent prognostic factor for overall survival. Multivariate analysis revealed that operation method, differentiation, perineural invasion, postoperative chemotherapy, tumor regression grade, and post-CRT CEA level were independent prognostic factors for overall survival.

CONCLUSION

The level of serum CEA after preoperative CRT was an independent prognostic factor for overall survival in patients with rectal cancer.

Clinical and molecular diagnosis of pathologic complete response in rectal cancer: an update

INTRODUCTION

The standard of care for locally advanced rectal cancer includes neoadjuvant chemoradiation with subsequent total mesorectal excision. This approach has shown various degrees of response to neoadjuvant chemoradiation (ranging from complete response to further tumor growth), which have substantial prognostic and therapeutic implications. A total regression of the tumor is a predictor of superior oncologic outcomes compared with partial responders and non-responders. Further, this concept has opened the possibility of nonoperative strategies for complete responders and explains the widespread research interest in finding clinical, radiographic, pathologic, and biochemical parameters that allow for identification of these patients. Areas covered: The present review evaluates the most recent efforts in the literature to identify predictors of patients likely to achieve a complete response following neoadjuvant treatment for the management of rectal cancer. This includes clinical predictors of pathologic complete response such as tumor location, size, and stage, molecular predictors such as tumor biology and microRNA, serum biomarkers such as carcinoembryogenic antigen and nomograms. Expert commentary: There has been significant progress in our ability to predict pathological complete response. However, more high-quality research is still needed to use this concept to confidently dictate clinical management.

Watch-and-Wait as a Therapeutic Strategy in Rectal Cancer

Purpose of Review

Pathological complete response is seen in approximately one fifth of rectal cancer patients following neoadjuvant chemoradiation. Since these patients have excellent oncological outcomes, there has been a rapidly growing interest in organ preservation for those who develop a clinical complete response. We review the watch-and-wait strategy and focus on all aspects of this hot topic, including who should be considered for this approach, how should we identify treatment response and what are the expected outcomes.

Recent Findings

The major challenges in interpreting the data on watch-and-wait are the significant heterogeneity of patients selected for this approach and of methods employed to identify them. The evidence available comes mostly from retrospective cohort studies, but has shown good oncological outcomes, including the rate of successful salvage surgery, locoregional control and overall survival.

Summary

There is currently not enough and not robust enough evidence to support watch-and-wait as a standard approach, outside a clinical trial, for patients achieving clinical complete response following neoadjuvant chemoradiation. Furthermore, there is a lack of data on long-term outcomes. However, the results we have so far are promising, and there is therefore an urgent need for randomised control studies such as the TRIGGER trial to confirm the safety of this strategy.

Relations of Changes in Serum Carcinoembryonic Antigen Levels before and after Neoadjuvant Chemoradiotherapy and after Surgery to Histologic Response and Outcomes in Patients with Locally Advanced Rectal Cancer

OBJECTIVES

The histologic response to neoadjuvant chemoradiotherapy (nCRT) has been intimately related to outcomes in locally advanced rectal cancer. Serum carcinoembryonic antigen (CEA) levels change after nCRT and after surgery as compared with before nCRT.

METHODS

The subjects were 149 patients with locally advanced rectal cancer who received nCRT between 2005 and 2013. The patients were divided into 4 groups according to the serum CEA levels: group 1, 55 patients with negative serum CEA levels before nCRT; group 2, 41 patients with positive serum CEA levels before nCRT that became negative after nCRT; group 3, 37 patients with positive serum CEA levels after nCRT that became negative after surgery; and group 4, 16 patients with positive serum CEA levels after nCRT as well as after surgery.

RESULTS

Pathological complete response, T downstaging, and tumor shrinkage were significantly higher in group 1 than in other groups. Disease-free survival was significantly poorer in group 4. The lack of a decrease in the serum CEA level in group 4 was most likely attributed to the persistence of micrometastases outside the resection field.

CONCLUSIONS

Changes in serum CEA levels measured before nCRT, after nCRT, and after surgery can be used to reliably predict the histologic response to nCRT and outcomes.

Elevated CEA is associated with worse survival in recurrent rectal cancer

This study investigated the prognostic impact of serum carcinoembryonic antigen (CEA) level in recurrent rectal cancer. We reviewed 745 patients who developed recurrence after curative treatment for rectal cancer between January 2000 and December 2012. Multivariate analyses for survival revealed that age > 60 years (p = 0.005), r-CEA ≥ 5 ng/ml (p < 0.001), disease free interval (DFI) < 12 months (p < 0.001), and palliative or conservative treatment (p < 0.001) were unfavorable factors.

A nomogram predicting pathological complete response to neoadjuvant chemoradiotherapy for locally advanced rectal cancer: implications for organ preservation strategies

PURPOSE

To determine predictors of pathological complete response (pCR) in locally advanced rectal cancer patients treated with neoadjuvant chemoradiotherapy (nCRT), and develop a predictive nomogram.

METHODS

A total of 522 locally advanced rectal cancer patients undergoing nCRT and curative resection between 2008 and 2014 were included. Uni- and multivariate analysis was performed to identify predictors of pCR. A nomogram was developed and validated by internal (n=425) and external validation (n=97).

RESULTS

With a median follow-up of 55 months, pCR was associated with better 5-year overall and disease-free survival, distant control, but similar local control. Logistic regression showed that post-CRT distance from the anal verge (OR =0.840, P = 0.022), post-CRT tumor size (OR = 0.565, P = 0.003), post-CRT circumferential extent of tumor (OR = 0.021, P < 0.001), pre-CRT CEA level (OR = 2.004, P = 0.033), and post-CRT CEA level (OR = 3.767, P = 0.038) were independently associated with pCR. A nomogram was developed with a C-index of 0.81 and 0.75 on internal and external validation, respectively.

CONCLUSION

pCR was associated with better long-term outcome. A nomogram was successfully developed to predict pCR. It could support decision-making in organ preservation strategies.

Pre-treatment carcinoembryonic antigen and outcome of patients with rectal cancer receiving neo-adjuvant chemo-radiation and surgical resection: a systematic review and meta-analysis

Neo-adjuvant chemo-radiation is the standard of care for patients with locally advanced rectal carcinoma. The aim of the present paper is to evaluate the relationship of the baseline serologic concentration of the carcinoembryonic antigen with the outcome. Data sources included MEDLINE and Web of Science databases. A systematic search of the databases by a predefined criterion has been conducted. Chemo-radiation followed by surgical resection of rectal tumors was the intervention of interest. From selected studies, the relationships between carcinoembryonic antigen and pathologic complete response, disease-free survival and overall survival were assessed. Carcinoembryonic antigen correlated significantly and inversely with the rate of pathologic complete responses (OR 2.00). Similar to this relationship, a low baseline carcinoembryonic antigen concentration was associated with a better disease-free survival (OR 1.88) and a better overall survival (OR 1.85). Heterogeneity of studies and publication bias were considerable in evaluating the relationship of baseline carcinoembryonic antigen and pathologic complete response. Baseline carcinoembryonic antigen should be regarded as a predictor of outcome of patients undergoing neo-adjuvant chemo-radiation. A calibration of the cutoff value from 5 to 3 ng/ml appears more appropriate to this patient population and should be evaluated in prospective trials.

Inferior mesenteric artery lymph node metastasis in rectal cancer treated with neoadjuvant chemoradiotherapy: Incidence, prediction and prognostic impact

AIM

To assess the effect of neoadjuvant chemoradiotherapy (nCRT) on inferior mesenteric artery (IMA) nodal metastasis and identify predictors for IMA nodal metastasis in locally advanced rectal cancer (LARC) after nCRT.

METHOD

Propensity score matching of 1167 patients with LARC was performed. Clinicopathological predictors and survival rates were analyzed using univariate and multivariate analyses.

RESULTS

Compared to surgery alone, nCRT reduced the incidence of IMA nodal metastasis (before matching, 4.8% vs 9.1%, p = 0.004; after matching, 4.3% vs 10.1%, p = 0.002). Logistic regression analysis revealed that poorly differentiated (OR = 5.955, p < 0.001), tumors located above the peritoneal reflection (OR = 3.513, p = 0.005), and preoperative CEA levels ≧10 ng/ml (OR = 4.774, p = 0.005) were associated with IMA nodal metastasis. Time intervals to surgery ≧6 weeks were associated with fewer IMA nodal metastasis (OR = 0.274, p = 0.009).Over a median 40-month follow-up, the 3-year overall survival and disease-free survival rates were 63.0% and 43.1% in IMA-positive patients, respectively, which were significantly lower than the corresponding 89.0% and 82.4% rates in IMA-negative patients. Cox regression analysis revealed that IMA nodal metastasis was independently associated with unfavorable 3-year DFS.

CONCLUSION

nCRT reduced the incidence of IMA node metastasis. Tumors located above the peritoneal reflection, poorly differentiated, and higher preoperative CEA levels were associated with IMA nodal metastasis after nCRT. IMA lymph node dissection is beneficial to certain patients with IMA nodal metastases, and the oncologic benefit may be improved if IMA nodal metastasis can be predicted.

Elevated platelet count as predictor of recurrence in rectal cancer patients undergoing preoperative chemoradiotherapy followed by surgery

The impact of systemic inflammatory response (SIR) on prognostic and predictive outcome in rectal cancer after neoadjuvant chemoradiotherapy (CRT) has not been fully investigated. This retrospective study enrolled 89 patients with locally advanced rectal cancer who underwent neoadjuvant CRT and for whom platelet (PLT) counts and SIR status [neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR)] were available. Both clinical values of PLT and SIR status in rectal cancer patients were investigated. Elevated PLT, NLR, PLR, and pathologic TNM stage III [ypN(+)] were associated with significantly poor overall survival (OS). Elevated PLT, NLR, and ypN(+) were shown to independently predict OS. Elevated PLT and ypN(+) significantly predicted poor disease-free survival (DFS). Elevated PLT was identified as the only independent predictor of DFS. PLT counts are a promising pre-CRT biomarker for predicting recurrence and poor prognosis in rectal cancer.

Nomogram basing pre-treatment parameters predicting early response for locally advanced rectal cancer with neoadjuvant chemotherapy alone: a subgroup efficacy analysis of FOWARC study

Objective

To develop an accurate model with pre-treatment parameters to predict tumor regression and down-staging in locally advanced rectal cancer patients, basing the cohort of preoperative chemotherapy alone in FOWARC study.

Patients and Methods

From Jan 2011 to Feb 2015, complete data was available for 137 out of 165 patients who received preoperative chemotherapy alone. All pre-treatment clinical parameters were collected. Tumor regression grade (TRG) 0-1 was defined as good regression, and pathological TNM stage (ypTNM) 0-I after neoadjuvant treatment was defined as good down-staging. Nomogram was established to predict tumor regression and down-staging. The predictive performance of the model was assessed with concordance index and calibration plots.

Results

Of the 137 patients, 10 had TRG 0 (complete regression); 32 patients, TRG 1; and 95 patients, TRG 2 and 3 (poor regression); 56 (40.9%) patients were classified as good down-staging with ypTNM stage 0-I. The predictive nomograms were developed to predict the probability of TRG 0-1 and good down-staging with a C-index of 0.72 (95% CI: 0.604-0.797) and 0.76 (95% CI: 0.681-0.844). Calibration plots showed good statistical performance on internal validation. Predictive factors in the models included tumor length, tumor circumferential extent, age, and ApoA1.

Conclusions

The model based on available clinical parameters could accurately predict early efficacy with neoadjuvant mFOLFOX6 chemotherapy alone, which might help in patient selection for optimized treatment.

Selecting stage ypT0-1N0 for locally advanced rectal cancer following preoperative chemoradiotherapy: implications for potential candidates of organ-sparing management

AIM

Local excision or a wait-and-see policy may offer the possibility of organ preservation for locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (CRT). Identifying associated factors of good responders (GR) with stage ypT0-1N0 would probably influence the selection of potential candidates who were theoretically eligible for organ-sparing management. This study was to establish a scoring system to select stage ypT0-1N0 for LARC following preoperative CRT.

METHOD

Between 2009 and 2014, 262 patients with middle and low LARC were treated with CRT and radical surgery. Clinicopathological data which were found to be significantly associated with GR were incorporated into a scoring system.

RESULTS

Fifty-seven (21.8%) patients were GR with stage ypT0-1N0 in the operative specimen. Multivariate analyses indicated that a low level of pretreatment carcinoembryonic antigen (CEA) and post-treatment CEA <2.55 ng/ml (P = 0.008 and P = 0.009 respectively) and long-axis diameter of residual tumours (P = 0.006) were independently associated with stage ypT0-1N0. The three factors were incorporated into a scoring system. Using receiver operating characteristic curve analysis, we determined a cutoff value of -0.3 for scores, at which the system's sensitivity was 71.9% and specificity 73.1%. When applied to testing samples, the sensitivity was 74.1% and specificity 76.2%.

CONCLUSION

We demonstrated that low levels of pretreatment and post-treatment CEA and the long-axis diameter of residual tumours were associated with stage ypT0-1N0 for LARC after CRT. Therefore, the three-factor scoring system may be used to select potential candidates for organ-sparing management.

Can serum dynamics of carcinoembryonic antigen level during neoadjuvant chemoradiotherapy in rectal cancer predict tumor response and recurrence? A multi-institutional retrospective study

PURPOSE

We evaluate whether the change of carcinoembryonic antigen (CEA) level before and after preoperative chemoradiotherapy (CRT) in rectal cancer affects tumor response and recurrence or not.

METHODS

We retrospectively analyzed 1447 rectal cancer patients who underwent preoperative CRT followed by curative surgery. All patients received preoperative radiotherapy of 50.4 Gy in 28 fractions with 5-fluorouracil or capecitabine. Total mesorectal excision was performed 4 to 8 weeks after preoperative CRT. CEA levels were checked before and after CRT. Clinical and pathologic factors were analyzed for tumor response and recurrence.

RESULTS

Post-CRT CEA level (cutoff value, 2.5 ng/mL) was not a significant factor for tumor response on the multivariate analysis (p = 0.095). Patients were categorized according to the pre- and post-CRT CEA level (group A: pre-CRT CEA ≤5 ng/mL; group B: pre-CRT CEA >5 ng/mL and post-CRT CEA ≤2.5 ng/mL; group C: pre-CRT CEA >5 ng/mL and post-CRT CEA >2.5 ng/mL). The relapse-free survival (RFS) at 5 years was significantly higher in group A than in groups B and C (82.6 vs. 73.7 % vs. 72.2 %, p < 0.001). The overall survival (OS) at 5 years was significantly higher in group A than in groups B and C (90.1 vs. 84.4 % vs. 83.4 %, p < 0.001). However, there is no significant difference for RFS and OS between groups B and C (all, p > 0.05).

CONCLUSIONS

Decline of elevated CEA level (>5 ng/mL) during preoperative chemoradiotherapy has no significant effect on tumor response and recurrence in rectal cancer.

Prognosis Can Be Predicted More Accurately Using Pre- and Postchemoradiotherapy Carcinoembryonic Antigen Levels Compared to Only Prechemoradiotherapy Carcinoembryonic Antigen Level in Locally Advanced Rectal Cancer Patients Who Received Neoadjuvant Chemoradiotherapy

We aimed to evaluate the prognostic value of a change in the carcinoembryonic antigen (CEA) level during neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanced rectal cancer. A total of 110 patients with clinical T3/T4 or node-positive disease underwent nCRT and curative total mesorectal resection from February 2006 to December 2013. Serum CEA level was measured before nCRT, after nCRT, and then again after surgery. A cut-off value for CEA level to predict prognosis was determined using the maximally selected log-rank test. According to the test, patients were classified into 3 groups, based on their CEA levels (Group A: pre-CRT CEA ≤3.2; Group B: pre-CRT CEA level >3.2 and post-CRT CEA ≤2.8; and Group C: pre-CRT CEA >3.2 and post-CRT CEA >2.8). The median follow-up time was 31.1 months. The 3-year disease-free survival (DFS) rates of Group A and Group B were similar, while Group C showed a significantly lower 3-year DFS rate (82.5% vs. 89.5% vs. 55.1%, respectively, P = 0.001). Other clinicopathological factors that showed statistical significance on univariate analysis were pre-CRT CEA, post-CRT CEA, tumor distance from the anal verge, surgery type, downstage, pathologic N stage, margin status and perineural invasion. The CEA group (P = 0.001) and tumor distance from the anal verge (P = 0.044) were significant prognostic factors for DFS on multivariate analysis. Post-CRT CEA level may be a useful prognostic factor in patients whose prognosis cannot be predicted exactly by pre-CRT CEA levels alone in the neoadjuvant treatment era. Combined pre-CRT CEA and post-CRT CEA levels enable us to predict prognosis more accurately and determine treatment and follow-up policies. Further large-scale studies are necessary to validate the prognostic value of CEA levels.

Rectal cancer with complete clinical response after neoadjuvant chemoradiotherapy, surgery, or "watch and wait"

PURPOSE

The purpose of this study was to compare the outcomes of patients treated with chemoradiotherapy with a complete clinical response followed by either a "watch and wait" strategy or a total mesorectal excision.

METHODS

This was an observational retrospective study from a single institute. Patients with locally advanced rectal cancer following chemoradiotherapy with a complete clinical response from January 1, 2007 to December 31, 2014 were included.

RESULTS

The study population consisted of 18 patients who opted for a "watch and wait" policy and 26 patients who underwent radical surgery after achieving a complete clinical response. Patients had no documented treatment complications under the watch and wait policy, while 13 patients who underwent radical surgery experienced significant morbidity. There were two local recurrences in the watch and wait group; both were treated with salvage resection and had no associated mortality. In the radical surgery group, 1 patient showed an incomplete pathologic response (ypT0N1), and the remaining 25 patients showed complete pathologic responses; 1 had a distant recurrence, which was managed non-operatively, and 2 patients died of unrelated causes. The 5-year overall survival rate and median disease-free survival time were 100% and 69.78 months in the watch and wait group and 92.30% and 89.04 months in the radical surgery group.

CONCLUSIONS

A watch and wait policy avoids the morbidity associated with radical surgery and preserves oncologic outcomes in our retrospective study from a single institute. It could be considered a therapeutic option in patients with locally advanced rectal cancer following chemoradiotherapy with a complete clinical response.

Predictors of Complete Response and Disease Recurrence Following Chemoradiation for Rectal Cancer

OBJECTIVE

Approximately 10-40% of rectal patients have a complete response (CR) to neoadjuvant chemoradiation (CRT), and these patients have improved survival. Thus, non-operative management ("watch-and-wait" approach) may be an option for select patients. We aimed to identify clinical predictors of CR following CRT.

METHODS

Patients treated with definitive CRT for T3-T4, locally unresectable T1-T2, low-lying T2, and/or node-positive rectal cancer from August 2004 to February 2015 were retrospectively reviewed. Most patients were treated with 50.4 Gy radiation and concurrent 5-fluoruracil or capecitabine. Patients were considered to have a CR if surgical pathology revealed ypT0N0M0 (operative management), or if they had no evidence of residual disease on clinical and radiographic assessment (non-operative management). Statistical analysis was carried out to determine predictors of CR and long-term outcomes.

RESULTS

Complete records were available on 138 patients. The median follow-up was 24.5 months. Thirty-six patients (26.3%) achieved a CR; 30/123 operatively managed patients (24.5%) and 6/15 (40%) non-operatively managed patients. None of the 10 patients with mucinous adenocarcinoma achieved a CR. Carcinoembryonic antigen (CEA) ≥5 μg/L at diagnosis (OR 0.190, 95% CI 0.037-0.971, p = 0.046), tumor size ≥3 cm (OR 0.123, 95% CI 0.020-0.745, p = 0.023), distance of tumor from the anal verge ≥3 cm (OR 0.091, 95% CI 0.013-0.613, p = 0.014), clinically node-positive disease at diagnosis (OR 0.201, 95% CI 0.045-0.895, p = 0.035), and interval from CRT to surgery ≥8 weeks (OR 5.267, 95% CI 1.068-25.961, p = 0.041) were independent predictors of CR. The CR group had longer 3-year distant metastasis-free survival (DMFS) (93.7 vs. 63.7%, p = 0.016) and 3-year disease-free survival (DFS) (91.1 vs. 67.8%, p = 0.038). Three-year locoregional control (LRC) (96.6 vs. 81.3%, p = 0.103) and overall survival (97.2 vs. 87.5%, p = 0.125) were higher in the CR group but this did not achieve statistical significance. CR was not an independent predictor of LRC, DMFS, or DFS.

CONCLUSION

CEA at diagnosis, tumor size, tumor distance from the anal verge, node positivity at diagnosis, and interval from CRT to surgery were predictors of CR. These clinical variables may offer insight into patient selection and timing of treatment response evaluation in the watch-and-wait approach.

New Perspectives on Predictive Biomarkers of Tumor Response and Their Clinical Application in Preoperative Chemoradiation Therapy for Rectal Cancer

Preoperative chemoradiation therapy (CRT) is the standard treatment for patients with locally advanced rectal cancer (LARC) and can improve local control and survival outcomes. However, the responses of individual tumors to CRT are not uniform and vary widely, from complete response to disease progression. Patients with resistant tumors can be exposed to irradiation and chemotherapy that are both expensive and at times toxic without benefit. In contrast, about 60% of tumors show tumor regression and T and N down-staging. Furthermore, a pathologic complete response (pCR), which is characterized by sterilization of all tumor cells, leads to an excellent prognosis and is observed in approximately 10-30% of cases. This variety in tumor response has lead to an increased need to develop a model predictive of responses to CRT in order to identify patients who will benefit from this multimodal treatment. Endoscopy, magnetic resonance imaging, positron emission tomography, serum carcinoembryonic antigen, and molecular biomarkers analyzed using immunohistochemistry and gene expression profiling are the most commonly used predictive models in preoperative CRT. Such modalities guide clinicians in choosing the best possible treatment options and the extent of surgery for each individual patient. However, there are still controversies regarding study outcomes, and a nomogram of combined models of future trends is needed to better predict patient response. The aim of this article was to review currently available tools for predicting tumor response after preoperative CRT in rectal cancer and to explore their applicability in clinical practice for tailored treatment.

Predictors of Pathologic Complete Response in Rectal Cancer Patients Undergoing Total Mesorectal Excision After Preoperative Chemoradiation

Preoperative chemoradiotherapy (CRT) is the standard of care for patients with stage II and III rectal cancer. This strategy leads to pathologic complete response (pCR) in a significant number of patients. Factors predictive of pCR are currently being extensively investigated. The aim of this study was to analyze clinical factors that might be predictive of pCR.This study was a retrospective analysis of rectal cancer patients from January 2004 through December 2012. A total of 332 stage II and III patients with middle and low rectal cancer (≤10 cm) who received CRT and underwent curative total mesorectal excision were eligible. The median radiation dose was 50.4 Gy, and 72.6% of patients received infusional 5-fluorouracil with leucovorin, whereas 19.6% of patients received TS-1 with irinotecan, and 7.8% of patients received xeloda only. Pathologic complete response was confirmed by using pathologic specimens and analyzed based on predictive clinical factors.Among the 332 patients, 27.4% (n = 91) achieved pCR. Age, sex, body mass index, clinical T and N stages, tumor differentiation, the chemotherapy agent for CRT, and the time interval between CRT and surgery did not differ between the pCR and non-pCR groups. Carcinoembryogenic antigen (CEA) levels before CRT were 4.61 ± 7.38 ng/mL in the pCR group and 10.49 ± 23.83 ng/mL in the non-pCR group (P = 0.035). Post-CRT CEA levels were 1.4 ± 1.07 ng/mL in the pCR group and 2.16 ± 2.8 ng/mL in the non-pCR group (P = 0.014), and the proportion of middle rectal cancer patients was higher in pCR group (54.9%, P = 0.028). The results from multivariate logistic regression analysis indicated that higher tumor location (odds ratio 2.151; P = 0.003) and low post-CRT CEA level (odds ratio 0.789; P = 0.04) were independent predictive factors for pCR.Tumor location and post-CRT CEA level were predictive factors in pCR for rectal cancer patients. Therefore, these factors may be important determinants in achieving pCR, and may also be used to predict oncologic outcomes.