Signet ring cell histology and non-circumferential tumors predict pathological complete response following neoadjuvant chemoradiation in rectal cancers

Systematic review of risk factors, prognosis, and management of colorectal signet-ring cell carcinoma

BACKGROUND

Colorectal signet-ring cell carcinoma (CSRCC) is a rare clinical entity which accounts for approximately 1% of all colorectal cancers. Although multiple studies concerning this specific topic have been published in the past decades, the pathogenesis, associated risk factors, and potential implications on treatment are still poorly understood. Besides the low incidence, historically confusing histological criteria have resulted in confusing data. Nevertheless, the rising incidence of CSRCC along with relatively young age at presentation and associated dismal prognosis, highlight the actual interest to synthesize the known literature regarding CSRCC.

AIM

To provide an updated overview of risk factors, prognosis, and management of CSRCC.

METHODS

A literature search in the MEDLINE/PubMed database was conducted with the following search terms used: 'Signet ring cell carcinoma' and 'colorectal'. Studies in English language, published after January 1980, were included. Studies included in the qualitative synthesis were evaluated for content concerning epidemiology, risk factors, and clinical, diagnostic, histological, and molecular features, as well as metastatic pattern and therapeutic management. If possible, presented data was extracted in order to present a more detailed overview of the literature.

RESULTS

In total, 67 articles were included for qualitative analysis, of which 54 were eligible for detailed data extraction. CSRCC has a reported incidence between 0.1%-2.4% and frequently presents with advanced disease stage at the time of diagnosis. CSRCC is associated with an impaired overall survival (5-year OS: 0%-46%) and a worse stage-corrected outcome compared to mucinous and not otherwise specified adenocarcinoma. The systematic use of exploratory laparoscopy to determine the presence of peritoneal metastases has been advised. Surgery is the mainstay of treatment, although the rates of curative resection in CSRCC (21%-82%) are lower compared to those in other histological types. In case of peritoneal metastasis, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy should only be proposed in selected patients.

CONCLUSION

CSRCC is a rare clinical entity most often characterized by young age and advanced disease at presentation. As such, diagnostic modalities and therapeutic approach should be tailored accordingly.

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.

Total Neoadjuvant Therapy Is a Predictor for Complete Pathological Response in Patients Undergoing Surgery for Rectal Cancer

INTRODUCTION

Total neoadjuvant therapy (TNT) is a new therapeutic strategy in patients with rectal cancer. We examined the role of TNT, in addition to other pre-operative factors, as a predictor for pathologic complete response (pCR).

METHODS

A retrospective analysis of all rectal cancer patients who underwent surgery between 2016 and 2021 was conducted. Patients were classified into two groups-pCR group and residual tumor group. Patient data were reviewed and entered into univariate and multivariate analyses to determine predictors of pCR.

RESULTS

A total of 172 patients were treated with neoadjuvant therapy and underwent surgery during the study period. Sixty patients (34.9%) were treated with TNT while 112 (65.1%) were treated with traditional neoadjuvant chemoradiation. The overall pCR rate was 25.6% (44 patients), with 31.6% (19 patients) in patients who received TNT compared to 22.3% (25 patients) in patients who received neoadjuvant chemoradiation (NCRT). Univariate analysis of clinical and radiological factors correlated with pCR demonstrated no significant differences between the two groups in cT stage (p = 0.46), cN stage (p = 0.52), positive circumferential resection margin (CRM) (p = 0.72), tumor location (p = 0.35), symptomatic presentation (p = 0.09), and anal sphincter involvement (p = 0.68). Multivariate logistic analysis demonstrated that only pre-operative TNT (OR:2.35; 95% CI 1.06-5.25; p = 0.03) was predictive of pCR, while extramural vascular invasion (EMVI) was a predictor for lower rates of pCR (OR: 0.28; 95% CI 0.09-0.9; p = 0.03).

CONCLUSION

Rectal cancer patients undergoing TNT prior to surgery have a higher chance of developing a complete pathologic response. Evaluation of this therapy should be continued and extended to larger numbers of patients to see if the differences we observed are real.

Factors influencing downstaging after neoadjuvant long-course chemoradiotherapy in rectal carcinoma

PURPOSE

This single-centre cohort study was designed to identify factors that can predict primary tumour downstaging by neoadjuvant chemoradiotherapy (nCRT) in rectal carcinoma.

METHODS

Prospectively collected data from 555 patients with clinical T category (cT) cT3-4 rectal carcinoma treated between 1995 and 2019 were retrospectively analysed. All patients received long-term neoadjuvant chemoradiotherapy followed by surgery with curative intent at the Department of Surgery, University Hospital Erlangen, Germany. Patient-, tumour- and treatment-related factors with a potential impact on the downstaging of rectal carcinoma to pathological T category (pT) ≤ ypT2 and ypT0 were analysed in univariate and multivariate logistic regression analyses. The prognosis of patients with and without downstaging of the primary tumour was compared.

RESULTS

A total of 288 (51.9%) patients showed downstaging to ≤ ypT2. Eighty-six (15.5%) patients achieved clinical complete regression (ypT0). In the multivariate logistic regression analysis, the factors cT category, BMI, ECOG score, CEA, histological type, extension in the rectum and year of the start of treatment were found to be independent factors for predicting downstaging to ≤ ypT2 after neoadjuvant chemoradiotherapy. The year of treatment initiation also remained an independent significant predictor for pathological complete regression. The prognosis was superior in patients with downstaging to ≤ ypT2 in terms of locoregional and distant recurrence as well as disease-free and overall survival.

CONCLUSION

Factors predicting downstaging after long-term nCRT could be identified. This may be helpful for counselling patients and selecting the optimal treatment for patients with advanced rectal carcinoma.

Trends in the Incidence and Survival Rates of Colorectal Signet-Ring Cell Carcinoma in the South Korean Population: Analysis of the Korea Central Cancer Registry Database

Objective: Signet-ring cell carcinoma (SRCC) is a rare histopathological subtype of colorectal cancer (CRC) constituting approximately 1% of CRC cases. This study analyzed the incidence and survival rates of colorectal SRCC. Methods: We analyzed the incidence and survival rates of colorectal SRCCs based on patients’ data of the Korea Central Cancer Registry. Results: The age-standardized incidence rates of colon and rectum SRCC in 2017 were 0.17 and 0.07 individuals per 100,000, respectively. Between 1993 and 2017, the 1-, 2-, 3-, 4-, and 5-year relative survival rates of patients with colon SRCC were 65.6%, 49.0%, 38.9%, 34.9%, and 33.0%, respectively, while those of patients with rectum SRCC were 69.6%, 47.8%, 38.5%, 32.8%, and 29.4%, respectively. According to the Surveillance, Epidemiology, and End Results summary stages, the 5-year relative survival rates of colon SRCC between 1993 and 2017 were 70.4% for the localized stage, 41.0% for the regional stage, and 7.0% for the distant stage, while those for rectum SRCC were 60.7%, 34.4, and 3.3%, respectively. Conclusions: Although the incidence of colorectal SRCC is extremely low in South Korea, it has been increasing in recent decades. As the prognosis of colorectal SRCC is extremely poor; clinicians should be aware of the differential diagnosis of SRCC in colorectal cancer cases.

Can histologic features predict neoadjuvant therapy response in rectal adenocarcinoma?

Current standard therapy for locally advanced rectal cancer (LARC) is neoadjuvant therapy followed by surgical resection; however, treatment response is variable among patients. This study aimed to identify histologic features that predict tumor response. This retrospective study included 105 patients with LARC, all of whom underwent biopsy followed by neoadjuvant therapy and subsequent surgical resection. Each patient's initial biopsy was evaluated for tumor grade, tumor budding, intraepithelial lymphocytes, intraepithelial neutrophils, desmoplasia, apoptosis, adjacent stromal lymphocytes, signet ring cells, mucinous features, tumoral Paneth cells, dirty necrosis, microscopic ulceration, and prominent lymphoid aggregates. These histologic features, along with patient age at diagnosis and tumor microsatellite status, were compared to tumor regression grades from the respective resection specimens. No histologic factors in tumor biopsies predictive of treatment response in post-therapy resection specimens were identified. Histologic features in pre-therapy biopsy samples of LARC do not predict subsequent response to neoadjuvant therapy. Effective and reliable methods to predict response to neoadjuvant therapy in rectal cancer remain elusive.

Predicting pathological response to chemoradiotherapy for rectal cancer: a systematic review

Introduction: Pathological complete response (pCR) rates of approximately 20% following neoadjuvant long-course chemoradiotherapy for rectal cancer have given rise to non-operative or watch-and-wait (W&W) management. To improve outcomes there has been significant research into predictors of response. The goal is to optimize selection for W&W, avoid chemoradiotherapy in those who won't benefit and improve treatment to maximize the clinical complete response (cCR) rate and the number of patients who can be considered for W&W.Areas covered: A systematic review of articles published 2008-2018 and indexed in PubMed, Embase or Medline was performed to identify predictors of pathological response (including pCR and recognized tumor regression grades) to fluoropyrimidine-based chemoradiotherapy in patients who underwent total mesorectal excision for rectal cancer. Evidence for clinical, biomarker and radiological predictors is discussed as well as potential future directions.Expert opinion: Our current ability to predict the response to chemoradiotherapy for rectal cancer is very limited. cCR of 40% has been achieved with total neoadjuvant therapy. If neoadjuvant treatment for rectal cancer continues to improve it is possible that the treatment for rectal cancer may eventually parallel that of anal squamous cell carcinoma, with surgery reserved for the minority of patients who don't respond to chemoradiotherapy.

Predictive factors associated with complete pathological response after neoadjuvant treatment for rectal cancer

PURPOSE

A proportion of 10 to 30% of patients treated by chemoradiotherapy followed by total mesorectal excision surgery for a locally advanced rectal cancer can achieve a complete pathological response. We aimed to identify predictive factors associated with complete pathological response or no response and to assess the impact of each response on survival rates.

PATIENTS AND METHODS

Patients treated with long course chemoradiotherapy for locally advanced and/or node positive rectal cancer from 2010 to 2016 were retrospectively reviewed. Statistical analysis was carried out to determine predictors of tumor regression and treatment outcomes.

RESULTS

Records were available on 70 patients. In the univariate analysis, clinical factors associated with complete tumor response were tumor mobility in digital rectal examination (P=0.047), a limited parietal invasion (P=0.001), clinically negative lymph node (P<0.001) and a circumferential extent greater than 50% (P=0.001). On the other hand, a T4 classification and an endoscopic tumor size greater than 6cm were associated with no response to treatment (P=0.049 and P=0.017 respectively). On multivariate analysis, T2 clinical classification and N0 statement before treatment were independent predictive factors of pathologic complete response (P<0.001 and P=0.001) and a delayed surgery after 12 weeks was associated with no response to treatment (P=0.001).

CONCLUSION

The identification of predictive factors of histological response may help clinicians to predict the prognosis and to propose organ preservation for good responders.

Predictive factors of complete pathological response in patients with locally advanced rectal cancer

PURPOSE

Patients with locally advanced rectal cancer who achieve pathologic complete response (pCR) following neoadjuvant therapy have better long-term outcomes and could be spared from the perioperative and long-term morbidity of rectal resection. The aim of this study was to identify factors that predict the ability to achieve pCR at completion of conventional neoadjuvant therapy, therefore determining their suitability for non-surgical management.

METHODS

A retrospective analysis was performed on data obtained from a prospectively maintained colorectal neoplasia database. Patients treated for biopsy-proven primary rectal adenocarcinoma between January 1, 2010, and February 28, 2018, who received neoadjuvant radiotherapy or chemoradiotherapy and had undergone surgical resection, were included in this study. Five-year oncologic outcome data was also obtained for 144 patients. Clinicopathological tumour characteristics and treatment regimens were analysed for correlation to clinical outcome.

RESULTS

Three hundred fifty-four patients met inclusion criteria for this study. We identified significant differences between patients achieving a pCR and those that did not for tumour type (adenocarcinoma vs. mucinous/signet ring; p = 0.008), pre-treatment serum CEA level (</≥ 2.5 μg/L; p = 0.003), neoadjuvant therapy type (short-course radiotherapy and long-course chemoradiotherapy; p = 0.008) and preoperative lymph node status (node-negative versus node-positive disease; p = 0.031). Additionally, this is the first report to our knowledge to identify a significant correlation with pCR and the degree of tumour fixity (mobile vs. fixed/tethered; p = 0.038).

CONCLUSIONS

This retrospective analysis identified factors that significantly impact a patients' ability to achieve a pCR, which may prove useful for prospectively selecting patients suitable for non-surgical management of disease.

Clinicopathological characteristics and survival in colorectal signet ring cell carcinoma: a population-based study

We aimed to reveal clinicopathological features and explore survival-related factors of colorectal signet ring cell carcinoma (SRCC). A population-based study was carried out to investigate colorectal SRCC by using data extracted from the surveillance, epidemiology and end results (SEER) database between 2004 and 2015. In total, 3,278 patients with colorectal SRCC were identified, with a median age of 63 (12–103) years old. The lesions of most patients (60.49%) were located in the cecum–transverse colon. In addition, 81.27% patients had advanced clinical stage (stage III/IV), and 76.69% patients had high pathological grade. The 3–, 5–year cancer‐specific survival and overall survival rate was 35.76%, 29.32% and 32.32%, 25.14%. Multivariate analysis revealed that primary site in cecum–transverse colon, married, received surgery, lymph node dissections ≥ 4 regional lymph nodes were independent favorable prognostic. Meanwhile, aged ≥ 65 years, higher grade, tumor size ˃5 cm and advanced AJCC stage were associated with poor prognosis. Patient age, tumor grade, marital status, tumor size, primary tumor location, AJCC stage, surgery and number of dissected lymph node had significant correlation with prognosis of colorectal SRCC.

Signet ring cell component in pretreatment biopsy predicts pathological response to preoperative chemoradiotherapy in rectal cancer

PURPOSE

Neoadjuvant therapy is routinely used in the management of locally advanced rectal cancer. This study aimed to evaluate the predictive value of pathological parameters in tumor response after treatment.

METHODS

We reviewed the hematoxylin-eosin slides from pretreatment biopsies of 150 rectal cancer patients who received preoperative chemoradiotherapy (PCRT) at Sun Yat-sen University Cancer Center between May 2013 and June 2016. Pathological and clinical parameters were both studied. The tumor response after chemoradiotherapy was evaluated using the tumor regression grade (TRG). Logistic regression was used to evaluate the relevance between these parameters and tumor response.

RESULTS

Complete tumor response (TRG0 and pCR) to PCRT was identified in 40 (26.7%) patients. The pCR rate was 93.33% (14 of 15) in cases with signet ring cell component versus 19.26% (26 of 135) in those without signet ring cell component (p < 0.001). Four cases with signet ring cell component were evaluated as clinical complete response (cCR), all of whom also achieved pCR; in contrast, only 9 of 15 (60%) cCR cases without signet ring cell achieved pCR.

CONCLUSION

Our data suggest that the signet ring cell component in pretreatment biopsies may be a potential predictor of tumor response to PCRT in rectal cancer. This suggests patients with clinical complete response are more suitable for a wait-and-watch approach.

Impact of delaying surgery after chemoradiation in rectal cancer: outcomes from a tertiary cancer centre in India

Background

Delaying surgery after chemoradiation is one of the strategies for increasing tumor regression in rectal cancer. Tumour regression and PCR are known to have positive impact on survival.

Methods

It's a retrospective study of 161 patients undergoing surgery after neoadjuvant chemoradiation (NCRT) for locally advanced rectal cancer (LARC). Patients were divided into three categories based on the gap between NCRT and surgery, i.e., <8, 8-12 and >12 weeks. Tumor regression grades (TRG), sphincter preservation, post-operative morbidity-mortality and survival were evaluated.

Results

Sphincter preservation was significantly less in >12 weeks group compared to the other two groups (P=0.003). Intraoperative blood loss was significantly higher in >12 weeks group compared to 8-12 weeks group (P=0.001).There was no difference in major postoperative morbidity and hospital stay among the groups. There was no significant correlation between delay and TRG (P=0.644). At Median follow up of 49.5 months the projected 3-year overall survival (OS) and disease free survival (DFS) were not significantly different among the 3 groups (OS: 79.5% vs. 83.3% vs. 76.5%; P=0.849 and DFS 50.4% vs. 70.6% vs. 62%; P=0.270 respectively).

Conclusions

Delaying surgery by more than 12 weeks causes more blood loss but no change in morbidity or hospital stay. Increased time interval between radiation and surgery does not improve tumor regression and has no effect on survival.

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.

Preoperative radiotherapy improves survival in rectal signet-ring cell carcinoma-a population-based study

Background

To investigate the clinical value of preoperative and postoperative radiotherapy (RT) in patients with rectal signet-ring cell carcinoma (SRCC).

Methods

Using the Surveillance, Epidemiology, and End Results program patients with stage II–III rectal SRCC were retrospectively included between 1988 and 2012. Univariate and multivariate Cox regression analyses were performed to analyze the effect of preoperative and postoperative RT on cause-specific survival (CSS).

Results

A total of 292 patients were included: 138 patients received preoperative RT, 101 patients received postoperative RT, and 53 patients underwent surgery alone. Overall, 5– and 10-year CSS was 43.8 and 37.6%, respectively. Preliminary survival analysis demonstrated that preoperative RT improved CSS versus surgery alone, especially in patients with stage III disease. Multivariate analysis demonstrated that preoperative RT was independent predictors for CSS in stage III rectal SRCC. CSS in preoperative and postoperative RT groups was comparable.

Conclusions

Preoperative RT significantly improved survival outcomes in patients with stage III rectal SRCC.

Role of CT scan in differentiating the type of colorectal cancer

Objectives

Most colorectal cancers are classical adenocarcinomas (AC), and less frequent subtypes include mucinous adenocarcinomas (MAC) and signet-ring cell carcinomas (SC). The purpose of this study was to evaluate the computed tomography (CT) findings that can help to differentiate MAC and SC from AC.

Methods

CT scans of 168 patients with pathologically proven MAC and 67 patients with pathologically proven SC were analyzed, and 220 patients with classical AC were also included as a control group. CT findings of the three groups were compared and contrasted in terms of the bowel involvement patterns, contrast enhancement patterns, and presence or absence of bowel obstruction, intratumoral calcification, pericolic fat infiltration, and local tumor extension to adjacent organs. Statistical analyses were made by using the one-way analysis of variance, least significant difference test, and Pearson’s chi-square test.

Results

Compared with classical AC, the MAC showed more severe (6.29±2.69 cm vs 4.57±1.74 cm, P<0.001) and higher percentage of occurrence of eccentric bowel-wall thickening (37.2% vs 11.5%, P<0.001). Heterogeneous contrast enhancement was most common in MAC (P<0.01), and MAC showed more areas with hypoattenuation (P<0.001). The presence of intratumoral calcification was most frequent in MAC (17.9% vs 2% vs 6.8%) (P<0.001); the SC also were more severe (5.75±2.28 cm vs 4.57±1.74 cm. P=0.001) than AC, but SC tend to show more cases of concentric even bowel-wall thickening (67.2%); homogeneous contrast enhancement was most common in SC (P<0.01), and it showed a target appearance. The presence of peritoneal seeding was most frequent in SC (35.8% vs 8% vs 2.7%, P<0.001), while the presence of regional lymph node metastasis (P=0.190) and direct invasion of adjacent organs or metastasis (P=0.323) were not significantly different among them.

Conclusion

Some radiological features by CT can be used to classify different colon tumor types.

Prognosis and value of preoperative radiotherapy in locally advanced rectal signet-ring cell carcinoma

As well known, signet-ring cell carcinoma (SRCC) is a rare histological subtype of colorectal adenocarcinoma, which has been associated with poor prognosis and resistant to non-surgery therapy compared with common adenocarcinoma. In this study, we assessed the effect of preoperative radiotherapy (PRT) for locally advanced rectal SRCC in a large patient group from the Surveillance, Epidemiology, and End Results program (SEER, 1988–2011) database. SRCC was found in 0.9% (n = 622) rectal cancer (RC) patients in our study. In the PRT setting, SRCC had significantly worse cancer-specific survival than mucinous adenocarcinoma and nonmucinous adenocarcinoma patients (log-rank, P < 0.001). In terms of SRCC, stage III RC patients benefited from PRT (log-rank, P < 0.001) while stage II did not (P = 0.095). The multivariate Cox proportional hazard model showed that PRT was an independent benefit factor in stage III rectal SRCC patients (HR, 0.611; 95% CI, 0.407–0.919; P = 0.018). In conclusion, SRCC was an independent predictor of poor prognosis in stage III RC patients, but not in stage II. In the PRT setting of locally advanced RC, SRCC patients had significantly worse prognosis. PRT was an independent prognostic factor associated with improved survival in stage III rectal SRCC.

Signet ring colorectal carcinoma: Do we need to improve the treatment algorithm?

AIM

To elaborate about this peculiar variant from a tertiary cancer center from India.

METHODS

It’s a retrospective study (2011-2014) of all patients diagnosed with signet ring colo-rectal cancer (SRCC). Various clinico-pathological variables were studied.

RESULTS

One hundred and seventy consecutive patients with SRCC were diagnosed (11.4% of all colorectal cancers). Median Age of the cohort was 41 years. Most common location was recto-sigmoid area (54.7%). Majority patients presented in stage III and IV (91.2%). Most of the stage IV patients had isolated peritoneal metastases (86.5%). Colonic tumors had higher incidence of peritoneal metastases (91.8% vs 83.3%) as well as isolated peritoneal recurrences (37.5% vs 16.7%) than rectal primaries. Thirty-seven point five percent of patients recurred after curative surgery. Amongst them 63.63% patients had isolated peritoneal recurrences. Circumferential resection margin (CRM) was involved in 17.9% patients. Median relapse free survival (RFS) and overall survival (OS) of the cohort were 14.9 and 18.13 mo respectively. CRM involvement, colonic primary were associated with poorer RFS and OS.

CONCLUSION

SRCC has predilection for peritoneal dissemination. More aggressive and/or extended chemotherapy schedules as well as prophylactic hyperthermic intra-peritoneal chemotherapy at the time of primary surgery may be attempted in these patients.

Advances for achieving a pathological complete response for rectal cancer after neoadjuvant therapy

Neoadjuvant therapy has become the standard of care for locally advanced mid-low rectal cancer. Pathological complete response (pCR) can be achieved in 12%–38% of patients. Patients with pCR have the most favorable long-term outcomes. Intensifying neoadjuvant therapy and extending the interval between termination of neoadjuvant treatment and surgery may increase the pCR rate. Growing evidence has raised the issue of whether local excision or observation rather than radical surgery is an alternative for patients who achieve a clinical complete response after neoadjuvant therapy. Herein, we highlight many of the advances and resultant controversies that are likely to dominate the research agenda for pCR of rectal cancer in the modern era.

Primary signet ring cell carcinoma of the colon and rectum

Colorectal primary signet ring cell carcinoma (SRCC) is a rare entity accounting for nearly 1% of all colorectal carcinomas. It is an independent prognostic factor associated with less favorable outcome. This aggressiveness is mainly due to the intrinsic biology of these tumors. Here is an overview of the literature related to clinicopathological features, molecular biology, and management of SRCC of the colon and the rectum.

Primary Linitis Plastica of the Rectum: Focus on Magnetic Resonance Imaging Patterns and Treatment Options

Case series

Patient: Male, 59 • Male, 85 • Male, 27

Final Diagnosis: refractory metastatic rectal cancer

Symptoms: —

Medication: —

Clinical Procedure: Chemotherapy

Specialty: Oncology

Normalization of CEA Levels Post-Neoadjuvant Therapy is a Strong Predictor of Pathologic Complete Response in Rectal Cancer

BACKGROUND

Recent attention has been focused on the relationship between carcinoembryonic antigen (CEA) and pathological complete response (pCR), without consensus regarding its predictive value. This study aims to examine the association between CEA and pCR.

METHODS

We conducted a retrospective review of a prospectively maintained database of all patients who underwent primary rectal cancer resection after neo-adjuvant chemoradiotherapy (nCRT). Patients were divided into two groups, pCR or no-pCR, based on final pathology. CEA levels were measured at the initial visit with the surgeon/oncologist and post-completion of nCRT.

RESULTS

One hundred and forty-one patients underwent primary rectal cancer resections after nCRT. Nineteen patients (13.5 %) achieved pCR, while 122 (86.5 %) had no-pCR. Pre-nCRT CEA levels were not significantly different between groups (2.75 vs 4.5 μg/L, p = 0.65). However, post-nCRT CEA levels were significantly lower in patients with pCR (1.7 vs 2.4 μg/L, p < 0.01). On multivariate logistic regression analyses, low post-nCRT CEA level was an independent predictor of pCR (OR 1.74, CI 1.06, 3.81) and normalization of CEA from an initially elevated level was a highly significant predictor of pCR (OR 64.8, CI 2.53, 18,371).

CONCLUSION

Low post-nCRT CEA is an independent predictor of pCR, and normalization of CEA post-nCRT is a strong predictor of pCR.

Factors influencing response to neoadjuvant chemoradiation and outcomes in rectal cancer patients: tertiary Indian cancer hospital experience

BACKGROUND

In the treatment of rectal cancers several randomized trials have demonstrated benefits of neoadjuvant chemoradiotherapy (NACRT) in downstaging as well as survival among these patients. We investigated the patient and tumor related variables dictating the outcomes in these patients.

METHODS

Biopsy proven treatment naive 182 rectal cancer patients underwent NACRT from June 2006 to December 2010. The entire patients received long course conventionally fractionated external beam radiotherapy with concurrent oral Capecitabine. At 6 weeks from completion of NACRT clinico-radiological assessment was carried out for surgical feasibility. All patients were given postoperative adjuvant chemotherapy either single agent or multi drug regimen depending upon biopsy report.

RESULTS

Among 182 patients, 131 (72%) underwent surgery and initial T stage and signet ring cell morphology were major determinant of operability. Among the 131 operated patients at median follow up of 36 months, 94 (72%) are alive and disease free. With a median follow up of 42 months the 5-year disease free survival (DFS) and overall survival (OS) was 60% and 77%. The majority of the failures were distal but with more advanced disease at presentation both local and distal failures were similar. While assessing survival by multivariate analysis patients having positive nodes post-surgery had a significantly poorer DFS (P=0.001), while signet ring cell morphology and pre-treatment carcino-embryonic antigen (CEA) levels strongly influenced OS (P=0.03).

CONCLUSIONS

The outcome of our patients were similar to World Literature and signet ring cell morphology, pre-treatment CEA level, and pathological nodal staging all were influential in determining survival. Besides this, the study also highlights the fact that tumours with signet ring cell morphology appearing in younger population with poor survival needs prospective evaluation for more intense CRT regimen and aggressive surgical resections.

CEA - a predictor for pathologic complete response after neoadjuvant therapy for rectal cancer

BACKGROUND

Preoperative chemoradiation therapy in patients with rectal cancer results in pathologic complete response in approximately 10% to 30% of patients. Accurate predictive factors for obtaining pathologic complete response would likely influence the selection of patients best treated by chemoradiation therapy as the primary treatment without radical surgery.

OBJECTIVE

The aim of this study was to evaluate the impact of tumor size, stage, location, circumferential extent, patient characteristics, and pretreatment CEA levels on the development of pathologic complete response after chemoradiation therapy.

DESIGN

This study is a retrospective review.

SETTINGS AND PATIENTS

Five hundred thirty patients treated with preoperative chemoradiation therapy and radical surgery for rectal adenocarcinoma between 1998 and 2011 were identified. A total of 469 patients remained after excluding patients with a history of pelvic radiation (n = 2), previous transanal endoscopic microsurgery or polypectomy of the primary lesion (n = 15), concurrent malignant tumor (n = 14), and no information about pre- or posttreatment T stage in the chart (n = 30). Preoperative CEA levels were available for 267 patients (57%).

INTERVENTIONS

Preoperative chemoradiation therapy and total mesorectal excision were performed in patients with rectal cancer.

MAIN OUTCOME

The primary outcome measured was pathologic complete response.

RESULTS

: Ninety-six patients (20%) were found to have a pathologic complete response in the operative specimen. Low pretreatment CEA (3.4 vs 9.6 ng/mL; p = 0.008) and smaller mean tumor size (4.2 vs 4.7 cm; p = 0.02) were significantly associated with pathologic complete response. Low CEA levels and interruption in chemoradiation therapy were significant predictors of pathologic complete response in the multivariate analysis. When stratifying for smoking status, low CEA level was significantly associated with pathologic complete response only in the group of nonsmokers (p = 0.02).

LIMITATIONS

This study was limited by its retrospective design, missing CEA values, and lack of tumor regression grade assessment.

CONCLUSIONS

We demonstrated an association between low pretreatment CEA levels, interruption in chemoradiation therapy, and pathologic complete response in patients treated with neoadjuvant chemoradiation therapy for locally advanced rectal cancer. The predictive value of CEA in smokers can be limited, and further studies are needed to evaluate the impact of smoking on the predictive value of CEA levels for pathologic complete response in rectal cancer.