Complete response to neoadjuvant chemoradiation for rectal cancer does not influence survival

Personalized medicine for locally advanced rectal cancer: five years of complete clinical response after neoadjuvant radiochemotherapy-a case report with a literature review

We present a case report of a 73-year-old male patient with a complete clinical response following neoadjuvant radiochemotherapy of mid-rectal adenocarcinoma. The patient was initially diagnosed with stage IIIB microsatellite stable mid-rectal adenocarcinoma in February 2017. During restaging in June 2017, which included rectoscopy, endosonography, computed tomography and magnetic resonance imaging, a complete clinical response was observed. After appropriate consultation, a watch-and-wait strategy was chosen. During stringent follow-up every 3 months for the first 3 years and thereafter every 6 months, no recurrence or regrowth was observed. After the fifth year of complete clinical response, we recommended an annual follow-up. As of November 2023, the patient has no signs of recurrence or late toxicity after radiochemotherapy. The omission of resection in patients with locally advanced rectal cancer and the establishment of a watch-and-wait strategy are currently under discussion as possible treatment courses in patients with complete clinical response. Long-term data on watch-and-wait strategies for patients with a complete clinical response in locally advanced rectal cancer are rare. A clear national and international accepted standardization of follow-up programs for patients managed by a watch-and-wait strategy in the long-term is missing. Here, we report the case of a patient who had undergone a follow-up program for more than five years and discuss the current literature. Our case report and literature review highlights that a watch-and-wait strategy does not seem to increase the risk of systemic disease or compromise survival outcomes in selected locally advanced rectal cancer patients. Thus, our case contributes to the growing body of knowledge on personalized and precision medicine for rectal cancer.

Prognostic Value of ctDNA Detection in Patients With Locally Advanced Rectal Cancer Undergoing Neoadjuvant Chemoradiotherapy: A Systematic Review and Meta-analysis

BACKGROUND

Circulating tumor DNA (ctDNA) is increasingly used as a biomarker for metastatic rectal cancer and has recently shown promising results in the early detection of recurrence risk.

METHODS

We conducted a systematic review and meta-analysis to explore the prognostic value of ctDNA detection in LARC patients undergoing neoadjuvant chemoradiotherapy (nCRT). We systematically searched electronic databases for observational or interventional studies that included LARC patients undergoing nCRT. Study selection according to the PRISMA guidelines and quality assessment of the REMARK tool for biomarker studies. The primary endpoint was the impact of ctDNA detection at different time points (baseline, post-nCRT, post-surgery) on relapse-free survival (RFS) and overall survival (OS). The secondary endpoint was to study the association between ctDNA detection and pathological complete response(pCR) at different time points.

RESULTS

After further review and analysis of the 625 articles initially retrieved, we finally included 10 eligible studies. We found no significant correlation between ctDNA detection at baseline and long-term survival outcomes or the probability of achieving a pCR. However, the presence of ctDNA at post-nCRT was associated with worse RFS (HR = 9.16, 95% CI, 5.48-15.32), worse OS (HR = 8.49, 95% CI, 2.20-32.72), and worse pCR results (OR = 0.40, 95%CI, 0.18-0.89). The correlation between the presence of ctDNA at post-surgery and worse RFS was more obvious (HR = 14.94; 95% CI, 7.48-9.83).

CONCLUSIONS

Our results suggest that ctDNA detection is a promising biomarker for the evaluation of response and prognosis in LARC patients undergoing nCRT, which merits further evaluation in the following prospective trials.

Surveillance strategies following curative resection and non-operative approach of rectal cancer: How and how long? Review of current recommendations

Different follow-up strategies are available for patients with rectal cancer following curative treatment. A combination of biochemical testing and imaging investigation, associated with physical examination are commonly used. However, there is currently no consensus about the types of tests to perform, the timing of the testing, and even the need for follow-up at all has been questioned. The aim of this study was to review the evidence of the impact of different follow-up tests and programs in patients with non-metastatic disease after definitive treatment of the primary. A literature review was performed of studies published on MEDLINE, EMBASE, the Cochrane Library and Web of Science up to November 2022. Current published guidelines from the most authoritative specialty societies were also reviewed. According to the follow-up strategies available, the office visit is not efficient but represents the only way to maintain direct contact with the patient and is recommended by all authoritative specialty societies. In colorectal cancer surveillance, carcinoembryonic antigen represents the only established tumor marker. Abdominal and chest computed tomography scan is recommended considering that the liver and lungs are the most common sites of recurrence. Since local relapse in rectal cancer is higher than in colon cancer, endoscopic surveillance is mandatory. Different follow-up regimens have been published but randomized comparisons and meta-analyses do not allow to determine whether intensive or less intensive follow-up had any significant influence on survival and recurrence detection rate. The available data do not allow the drawing of final conclusions on the ideal surveillance methods and the frequency with which they should be applied. It is very useful and urgent for clinicians to identify a cost-effective strategy that allows early identification of recurrence with a special focus for high-risk patients and patients undergoing a “watch and wait” approach.

Transanal Endoscopic Microsurgery Versus Total Mesorectal Excision in ypT0-1 Rectal Cancer After Preoperative Radiochemotherapy: Postoperative Morbidity, Functional Results, and Long-term Oncologic Outcome

BACKGROUND

In patients with locally advanced extraperitoneal rectal cancer, a multidisciplinary approach represents the standard treatment. However, considering the favorable prognosis in patients with major or complete response, radical surgery might represent overtreatment.

OBJECTIVE

This study aimed to evaluate postoperative short-term morbidity, functional outcome, and oncologic long-term outcome in patients with rectal cancer treated with local excision by transanal endoscopic microsurgery or radical surgery and to determine who achieved a complete or major pathological response (ypT0-1) after neoadjuvant treatment.

DESIGN

This was a retrospective study.

SETTING

The study was conducted at a single center.

PATIENTS

Patients who had received neoadjuvant treatment by local excision with a major or complete pathological response at histological examination (transanal endoscopic microsurgery group) were compared to patients treated by radical surgery with the same pathological response (total mesorectal excision group).

INTERVENTIONS

The interventions included local excision by transanal endoscopic microsurgery and radical surgery with total mesorectal excision.

MAIN OUTCOME MEASURES

Postoperative short-term morbidity, functional outcome 1 year after surgery, and oncologic long-term outcome were measured.

RESULTS

Ninety-three patients were included in the study (35 in the transanal endoscopic microsurgery group and 58 in the mesorectal excision group). In the total mesorectal excision group, a sphincter-saving approach was possible in 89.7% (vs 100%; p = 0.049); a protective temporary stoma was necessary in 74.1% of radical procedures (vs 0%; p < 0.001), and 13.8% of these became permanent. Short-term postoperative morbidity was lower after local excision (14.3% vs 46.6%; p = 0.002). One year after surgery, the transanal endoscopic microsurgery group recorded better evacuation and continence function than the total mesorectal excision group. Oncologic outcome was similar between the groups.

LIMITATIONS

This study had a retrospective design.

CONCLUSION

If a major or complete pathological response occurs after neoadjuvant treatment, an organ-sparing approach by local excision seems to offer the same oncologic results as radical surgery, but it has a better postoperative morbidity rate and better functional results. See Video Abstract at http://links.lww.com/DCR/B901 .Microcirugía endoscópica transanal versus escisión total del mesorrecto en cáncer de recto ypT0-1 después de radioquimioterapia preoperatoria: morbilidad posoperatoria, resultados funcionales y resultado oncológico a largo plazo.

ANTECEDENTES

En pacientes con cáncer rectal extraperitoneal localmente avanzado, un abordaje multidisciplinario con radioquimioterapia preoperatoria y cirugía con escisión total del mesorrecto representa el tratamiento estándar. En pacientes que obtienen una respuesta mayor o completa, la cirugía radical puede representar un sobretratamiento, considerando el pronóstico favorable de estos casos.

OBJETIVO

Evaluar la morbilidad posoperatoria a corto plazo, el resultado funcional y el resultado oncológico a largo plazo en pacientes con cáncer de recto tratados con escisión local mediante microcirugía endoscópica transanal o mediante cirugía radical y que obtuvieron una respuesta patológica completa o mayor (ypT0-1) después del tratamiento neoadyuvante.

DISEO

Este fue un estudio retrospectivo.

AJUSTE

El estudio se realizó en un solo centro.

ESCENARIO

El estudio se realizó en un solo centro.

PACIENTES

Se comparó a los pacientes tratados, tras tratamiento neoadyuvante (1996-2016), mediante escisión local con respuesta patológica mayor o completa al examen histológico (grupo de microcirugía endoscópica transanal), con los pacientes tratados mediante cirugía radical con la misma respuesta patológica (grupo de escisión mesorrectal total).

INTERVENCIONES

Extirpación local mediante microcirugía endoscópica transanal y cirugía radical con escisión mesorrectal total.

PRINCIPALES MEDIDAS DE RESULTADO

Morbilidad posoperatoria a corto plazo, resultado funcional a un año después de la cirugía (evaluado con una puntuación de evacuación y continencia) y resultado oncológico a largo plazo.

LIMITACIONES

Las limitaciones de este estudio incluyen su diseño retrospectivo.

CONCLUSIN

Si se produce una respuesta patológica mayor o completa después del tratamiento neoadyuvante, un abordaje con preservación de órganos mediante escisión local parece ofrecer los mismos resultados oncológicos que la cirugía radical, pero tiene una menor tasa de morbilidad postoperatoria y mejores resultados funcionales un año después de la cirugía. Consulte Video Resumen en http://links.lww.com/DCR/B901 . (Traducción-Dr. Felipe Bellolio ).

Comparison of tumor regression grade and clinical stage based on MRI image as a selection criterion for non-radical management after concurrent chemoradiotherapy in locally advanced rectal cancer: a multicenter, retrospective, cross-sectional study

PURPOSE

There has been no comparative study on the clinical value of magnetic resonance tumor regression grade (mrTRG)1-2 and ycT0-1N0 for the prediction of ypT0-1N0 after concurrent chemoradiotherapy (CCRT) for rectal cancer. We compared the diagnostic performance between mrTRG1-2 and ycT0-1N0 for predicting ypT0-1N0 as a selection criterion for non-radical management after CCRT in locally advanced rectal cancer.

METHODS

This retrospective study enrolled 291 patients from three referral hospitals between January 2018 and March 2020. The diagnostic performance of ycT0-1N0 and mrTRG1-2 for the prediction of ypT0-1N0 was compared in terms of sensitivity, specificity, positive-predictive value, negative-predictive value, and area under the curve (AUC).

RESULTS

Sixty-eight patients (23.4%) achieved ypT0-1N0. Nineteen patients (6.5%) had ycT0-1N0, and 91 patients (31.2%) had mrTRG1-2. For predicting ypT0-1N0, ycT0-1N0 had a sensitivity of 16.2% (95% confidence interval [CI]: 8.36‒27.10) and positive-predictive value of 57.9% (95% CI: 36.57‒76.63), while mrTRG1-2 had a sensitivity of 58.8% (95% CI: 46.23‒70.63) and positive-predictive value of 44.0% (95% CI: 36.46‒51.74). When predicting ypT0-1N0, mrTRG1-2 showed a higher AUC (0.680, 95% CI: 0.604‒0.756) than ycT0-1N0 (0.563, 95% CI: 0.481‒0.645) (P < 0.001).

CONCLUSION

mrTRG1-2 might be a better indicator than ycT0-1N0 for the selection of non-radical management of advanced rectal cancer post-CCRT. However, additional diagnostic tools are required for predicting ypT0-1N0 because mrTRG1-2 or yc stage on MRI has insufficient evidence for diagnosing ypT0-1N0.

Evaluating disparities in delivery of neoadjuvant guideline-based chemoradiation for rectal cancer: A multicenter, propensity score-weighted cohort study

BACKGROUND

Despite guideline recommendations, some patients still receive care inappropriate for their clinical stage of disease. Identification of factors that contribute to variation in guideline base care may help eradicate disparities in the treatment of early and locally advanced rectal cancer.

METHODS

The American College of Surgeons National Cancer Database from 2010 to 2015 was analyzed with propensity score weighting to identify factors associated with delivery and omission of neoadjuvant guideline-based chemoradiation (GBC) for those with early and locally advanced rectal cancer.

RESULTS

Only 74% of patients with rectal cancer received stage-appropriate neoadjuvant chemoradiation; 4544 (88%) of those with early stage disease and 8675 (68%) in locally advanced disease. Chemotherapy and radiotherapy were not planned in 27% and 34% respectively, of those who did not receive GBC. Factors associated with receipt of non-guideline-based neoadjuvant chemoradiation were age >65 years, Medicare insurance, treatment at a community facility, West-South-Central geography, having locally advanced disease, and Charlson-Deyo score >3. Receipt of ideal guideline-based neoadjuvant chemoradiation conferred a survival benefit at 5 years.

CONCLUSION

Patient and non-patient factors contribute to disparities in guideline-based delivery of neoadjuvant chemoradiation in the treatment of rectal cancer. Identification of these risk factors are important to help standardize care and improve survival outcomes.

Association Between Pathological Complete Response and Tumor Location in Patients with Rectal Cancer After Neoadjuvant Chemoradiotherapy, a Prospective Cohort Study

Background: Colorectal cancers are the third common malignancies after lung and breast neoplasms. Some contributing factors for pathological complete response (pCR) to neoadjuvant therapy of rectal cancer have been defined. Despite various studies in this era, there are few studies on the location of tumors. Objectives: Regarding the high prevalence of colorectal cancer in Iran and the importance of neoadjuvant chemoradiation for survival and morbidity, this study was carried out to determine the association between pathologic complete response and tumor location in patients with rectal cancer after neoadjuvant chemoradiotherapy. Methods: In this prospective cohort, 100 cases with rectal adenocarcinoma from 2017 to 2019 were enrolled. Distance between anal verge and tumor was measured by clinical examination, colonoscopy, endo-sonography, and MRI. Tumors were defined as distal (less than 5 cm from the anal verge) and none distal (more than 5 cm from the anal verge). Another subdivision was inferior (0 - 4.99 cm), middle (5 - 9.99 cm), and superior (10 - 15 cm). The pathological response was compared across the groups. Results: In this study, the pCR was seen in 30%. In univariate analysis body mass index (BMI), grade, N-stage, and distance from anal verge were related to pCR. In cases with BMI over 25 kg/m2 and in tumors with low to medium grade N0/N1, and distance less than 5 cm from the anal verge (low lying tumors) the pCR to neoadjuvant treatment was higher. In multivariate analysis tumor grade, N stage, and distance from anal verge were still related to pCR. Conclusions: According to the obtained results in this study, there may be some association between rectal tumor location and pathologic complete response.

How to measure tumour response in rectal cancer? An explanation of discrepancies and suggestions for improvement

Various methods categorize tumour response after neoadjuvant therapy, including down-staging and tumour regression grading. Response categories allow comparison of different treatments within clinical trials and predict outcome. A reproducible response categorization could identify subgroups with high or low risk for the most appropriate subsequent treatments, like watch and wait. Lack of standardization and interpretation difficulties currently limit the usability of these approaches. In this review we describe these difficulties for the evaluation of chemoradiation in rectal cancer. An alternative approach of tumour response is based on patterns of residual disease, including fragmentation. We summarise the evidence behind this alternative method of response categorisation, which explains a number of very relevant clinical discrepancies. These issues include differences between downstaging and tumour regression, high local regrowth in advanced tumours during watchful waiting procedures, the importance of resection margins, the limited value of post-treatment biopsies and the relatively poor outcome of patients with a near complete pathological response. Recognition of these patterns of response can allow meaningful development of novel biomarkers in the future.

The risk of nodal disease in patients with pathological complete responses after neoadjuvant chemoradiation for rectal cancer: a systematic review, meta-analysis, and meta-regression

BACKGROUND

This systematic review and meta-analysis seek to evaluate the prevalence of nodal disease in rectal cancer patients with pathological complete responses (pCR) after neoadjuvant chemoradiotherapy (ypT0N+).

METHODS

This study conformed to the PRISMA guidelines. A search was performed on major databases to identify relevant articles. Meta-analyses of pooled proportions were performed on rectal cancer with pCR and ypT0N+. Meta-regression was undertaken to identify sources of heterogeneity, and the Newcastle-Ottawa Scale (NOS) was employed to assess the risk of bias.

RESULTS

A total of 18 studies were included, totaling 7568 patients. The overall risk of bias was low, since all studies scored 6 and above out of 9 on the NOS. Preoperatively, the pooled proportions of patients with T3/T4 tumors and clinically positive nodal disease were 84.08% (95% CI 74.19 to 91.99%) and 52.14% (95% CI 35.02 to 69.00%) respectively. The prevalence of pCR in the whole pool was 18.52% (95% CI 13.31 to 24.35%; I² = 93.85%; P = 0.00), and meta-regression showed a significantly negative relationship with patient age (β = - 0.03, 95% CI - 0.03 to - 0.02; P = 0.00). The pooled prevalence of ypT0N+ was 4.61% (95% CI 2.41 to 7.28%; I² = 52.27%; P = 0.01), and meta-regression demonstrated a significantly positive relationship with male gender (β = 1.06, 95% CI 1.00 to 1.12; P = 0.04).

CONCLUSION

There is a small risk of ypN+ in patients with pCR after neoadjuvant CRT and surgery for rectal cancer. However, further research is warranted to establish these findings and to identify predictive factors for this specific group of patients.

Tertiary Care Multidisciplinary Teams Associated with Improved Survival in Rectal Cancer Patients: A Comparative Study

For stage II/III rectal cancer patients, comprehensive multidisciplinary care (MDC) affects outcomes. Randomized trials have shown the effectiveness of adjuvant and neoadjuvant therapy in treatment of these patients. However, the effectiveness of collaboration within MDC is undetermined. It is possible that regional variation in survival outcomes may be tied to treatment facility. We retrospectively reviewed a prospectively collected database of patients with stage II/III rectal cancer who received MDC at any location and underwent oncologic colorectal resection at a tertiary care center (TCC) between 2005 and 2011. Of the 571 rectal cancer patients, 391 had a stage II/III rectal cancer and received surgery at a TCC. After exclusion criteria, we observed that 120 patients received neoadjuvant therapy and 119 patients received adjuvant therapy. For neoadjuvant patients, no difference in overall survival was observed between treatment received at a TCC versus an outside facility. However, a significant improvement in survival was observed in patients who received adjuvant therapy at a TCC ( P = 0.01). Thus, the location of postoperative adjuvant therapy shows improvement in 10-year survival at a TCC versus elsewhere. Thus, standardization of care can impact outcomes for invasive rectal cancer patients. The limitations of this study are its retrospective nature and relatively small sample size.

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.

Report from the 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference; Winnipeg, Manitoba; 29-30 September 2017

The 19th annual Western Canadian Gastrointestinal Cancer Consensus Conference (wcgccc) was held in Winnipeg, Manitoba, 29-30 September 2017. The wcgccc is an interactive multidisciplinary conference attended by health care professionals from across Western Canada (British Columbia, Alberta, Saskatchewan, and Manitoba) who are involved in the care of patients with gastrointestinal cancer. Surgical, medical, and radiation oncologists; pathologists; radiologists; and allied health care professionals participated in presentation and discussion sessions for the purpose of developing the recommendations presented here. This consensus statement addresses current issues in the management of colorectal cancer.

The Predictive Value of Clinical Evaluation of Response to Neoadjuvant Chemoradiation Therapy for Rectal Cancer

Introduction

Multimodality therapy has become the standard treatment for patients with locally advanced (T3 and T4) rectal carcinoma. Accurate preoperative staging of the patients with rectal cancer has increased in importance because the selection of patients with transmural rectal cancer (T3 or T4) or node-positive disease leads to a previous nonsurgical neoadjuvant treatment. The purpose of this study was to evaluate the predictive value of the clinical response to neoadjuvant therapy on the basis of pathological results obtained on rectal cancer patients treated by chemoradiotherapy and surgery.

Methods

From 1994 to 2003, 58 patients with a primary diagnosis of rectal cancer were studied at our department and enrolled in a neoadjuvant protocol of chemoradiotherapy followed by surgery. All patients were treated by 30 days of chemoradiotherapy. At the end of the chemoradiotherapy, each patient underwent clinical examination, including digital rectal examination, proctoscopy and abdominal-pelvic computerized tomography to define the clinical response to the chemoradiotherapy. Surgical resection was performed in all patients three weeks after the end of chemoradiotherapy, and histological analysis was performed on all resected specimens.

Results

The clinical complete response rate corresponded to the pathological complete response rate, whereas the clinical evaluation overestimated partial response and stable disease. The pathologic examination revealed that 3.5% of clinical partial responses and 3.4% of clinical stable disease were really pathological progressive disease. Clinical partial response and clinical stable disease positive predictive values were 92.8% and 90.9%, respectively, whereas the clinical progressive disease negative predictive value was 20%. Then, 6.9% of patients believed to have responded to the therapy, or not to have responded or worsened, actually had worsened by the end of the chemoradiotherapy.

Conclusions

Positive and negative predictive values, in particular for partial response and stable disease, of clinical evaluation of the response to chemoradiotherapy were not high enough to consider clinical evaluation accurate enough to make treatment decisions.

Transanal endoscopic microsurgery after neoadjuvant radiochemotherapy for locally advanced extraperitoneal rectal cancer

PURPOSE

The aim of this study is to provide a prospective analysis of post-operative and oncological outcomes in patients affected by locally advanced rectal cancer (LARC), who obtained a major/complete clinical response after pre-operative radio-chemotherapy (RCT) and were treated with local excision (LE) by trans-anal endoscopic microsurgery (TEM) to confirm a pathological complete response (pCR) after to neo-adjuvant RCT.

METHODS

All patients with LARC treated by pre-operative RCT and full-thickness LE by TEM (2000-2014) were included in the study. If the pathological analysis confirmed near complete or pCR, intensive follow up was proposed. If the pathological response was incomplete, a radical resection with TME was proposed. Post-operative (according to Clavien's classification), functional and long-term oncological outcome were analyzed.

RESULTS

36 patients were treated by TEM. The median post-operative hospital stay was 5 days. The post-operative morbidity was 41.6% (no grade ≥3). At pathological analysis, 23 specimens were ypT0 TRG1, and 4 were ypT1 TRG2. In 9 cases (ypT>1 and/or TRG>2), radical surgery with TME was proposed but 3 refused it. Median follow-up was 68 months. One local recurrence and 4 distant metastases occurred. The 5-yr actuarial local control, overall survival and disease-free survival were 96.0%, 92.0% and 82.8%.

CONCLUSIONS

In case of major or complete clinical response of LARC after pre-operative RCT, LE by TEM can be used to confirm the pathological response. This avoids the necessity of radical surgery and, in our experience, this approach seems to guarantee oncological safety with the functional advantages of an organ-sparing procedure.

Outcome and Salvage Surgery Following "Watch and Wait" for Rectal Cancer after Neoadjuvant Therapy: A Systematic Review

BACKGROUND

Currently there is no reliable test to predict pathological complete response following neoadjuvant chemoradiotherapy for rectal cancer. However, there is increasing interest in using clinical complete response as a surrogate marker, allowing a subset of patients with locally advanced rectal cancer to be allocated into a "watch and wait" pathway. Little is known about the oncological safety of the "watch and wait" approach or the rate of salvage surgery in cases of tumor regrowth. This information is critical for the implementation of this approach.

OBJECTIVE

The aim of this study is to assess the rate of salvage surgery and associated oncological outcomes for patients who develop a tumor regrowth with the "watch and wait" approach.

DATA SOURCES

Relevant studies were identified through PubMed, Embase, and Google Scholar search.

STUDY SELECTION

A systematic review was undertaken of studies assessing patients selected for the "watch and wait" approach according to PRISMA guidelines.

MAIN OUTCOME MEASURES

The associated tumor regrowth, salvage surgery, and disease-free and overall survival rates were assessed.

RESULTS

Five retrospective and 4 prospective observational studies were included into the analysis, with a total of 370 patients in the "watch and wait" group, of which 256 (69.2%) had persistent clinical complete response. Of those who had tumor regrowth, salvage surgery was possible in 83.8%. There was no difference in overall survival and disease-free survival between patients who received immediate surgery and the "watch and wait" group.

LIMITATIONS

The limitations of this study include its retrospective nature and small sample size. Furthermore, there is significant heterogeneity between study protocols, including the short median follow-up, given that tumor regrowth and distant metastasis may manifest at a later time point.

CONCLUSION

The majority of patients with tumor regrowth can be salvaged with definite surgery after "watch and wait." However, there is insufficient evidence to draw firm conclusions on the oncological safety of this approach; therefore, it is currently not the standard of care for locally advanced rectal cancer.

A phase II study of a modified FOLFOX6 regimen as neoadjuvant chemotherapy for locally advanced gastric cancer

Background:

We evaluated the efficacy and safety of the modified FOLFOX6 (mFOLFOX6) regimen as a neoadjuvant chemotherapy in gastric cancer patients.

Methods:

Seventy-three patients with T2–T4 or N+ were enroled. Preoperative chemotherapy consisted of three cycles of mFOLFOX6. The primary end points were the response rate and the R0 resection rate. Prognostic factors for overall survival (OS) were investigated using univariate and multivariate analyses.

Results:

Sixty-seven (91.8%) patients completed 3 cycles, with grade 3–4 toxicity arising in 33.0%. The radiology response rate was 45.8%. Sixty-seven (91.8%) patients receiving radical surgery showed different levels of histological regression of the primary tumour, with a ⩾50% regression rate of 49.2%. ypTNM stage (HR 4.045, 95% CI 1.429–11.446) and tumours of diffuse and mixed type (HR 9.963, 95% CI 1.937–51.235; HR 8.890, 95% CI 1.157–68.323, respectively) were significantly associated with OS. The pathologic regression rate (GHR; ⩾2/3/<2/3, ⩾50%/<50%) was statistically significantly associated with OS according to a univariate analysis.

Conclusions:

Perioperative mFOLFOX6 was a tolerable and effective regimen for gastric cancer. The ypTNM stage was an independent predictor of survival. GHR ⩾50%/<50% could be used as a surrogate marker for selecting a postoperative chemotherapy regimen.

Reduction in the size of enlarged pelvic lymph nodes after chemoradiation therapy is associated with fewer lymph node metastases in locally advanced rectal carcinoma

PURPOSE

We hypothesized that a reduction in the size of the lymph nodes after neoadjuvant therapy for locally advanced rectal carcinoma would be associated with decreased lymph node metastases and/or a better prognosis.

METHODS

Between March 2006 and April 2012, 71 patients with primary rectal cancer received neoadjuvant chemoradiation therapy (CRT). For all lymph nodes 5 mm or larger in size, the major and minor axes were measured on CT scan images, and the product was calculated. The lymph node size was determined before and after CRT. The patients were divided into three groups based on the lymph node size before and after treatment. Group A exhibited a reduction in size of 60% or more, Group B a reduction of less than 60% and Group C had no lymph node enlargement before treatment.

RESULTS

The incidence of lymph node metastases on pathological examination was 15% in Group A and 50% in Group B (p = 0.006). The five-year disease-free survival in Group A was 84% compared with 78% in Group B (log rank p = 0.34). The five-year overall survival in Group A was 92% compared with 74% in Group B (log rank p = 0.088).

CONCLUSIONS

A reduction in the size of enlarged lymph nodes after neoadjuvant therapy may be a useful prognostic factor for recurrence and survival.

Relationship between histologic response and the degree of tumor shrinkage after chemoradiotherapy in patients with locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiotherapy (CRT) significantly decreases local recurrence in advanced rectal cancer. We studied whether the degree of tumor shrinkage can be used as a predictor of histologic response.

METHODS

The subjects were 114 patients with locally advanced rectal cancer who underwent total mesorectal excision after receiving radiotherapy combined with uracil/tegafur (UFT) or S-1. The degree of tumor shrinkage based on barium enema examination and magnetic resonance imaging (MRI) were assessed before CRT and immediately before surgery.

RESULTS

A histologic complete response (ypCR), histologic marked regression, T and N downstaging were associated with significantly higher tumor-shrinkage rates on barium enema (P < 0.01, P < 0.01, P < 0.01, and P < 0.01, respectively) as well as on MRI (P < 0.01, P < 0.01, P < 0.01, and P = 0.01, respectively). On multivariate analysis, ypCR and histologic marked regression were significantly related only to tumor-shrinkage rates on barium enema (P < 0.01 and P < 0.01, respectively), and were not related to tumor-shrinkage rates on MRI.

CONCLUSIONS

The degree of tumor shrinkage is closely related to the final histologic response. Two-dimensionally evaluated tumor-shrinkage rates based on barium enema are adequate for the prediction of histologic response.

Non-operative management for locally advanced rectal cancer: critical review and future perspective

SUMMARY Over the last few decades we have observed important advances in diagnostic imaging, surgery, pathology and multimodal treatments for rectal cancer, as well as increased efforts to reduce treatment-related toxicities and preserve quality of life for curatively treated patients. Neoadjuvant short-course radiotherapy and long-course chemoradiotherapy followed by total mesorectal excision remain widely accepted as the standard of care for patients with locally advanced rectal cancer. However, a carefully selected group of patients achieving a complete response to neoadjuvant chemoradiotherapy may be spared the effects of surgery and achieve satisfactory oncologic outcomes with a ‘wait-and-see’ strategy. Although supported by the results of previous studies, this intriguing paradigm shift needs prospective evaluation within a clinical trial setting and a more accurate prediction and assessment of response by means of tumor biomarkers and diagnostic imaging.

Distribution of residual cancer cells in the bowel wall after neoadjuvant chemoradiation in patients with rectal cancer

BACKGROUND

The standard treatment for locally advanced rectal cancer is preoperative chemoradiation and total mesorectal excision. After surgery, tumors are classified according to the depth of tumor invasion, nodal involvement, and tumor regression grade. However, these staging systems do not provide information about the distribution of residual cancer cells within the bowel wall.

OBJECTIVE

This study aimed to determine the distribution of residual cancer cells in each layer of the bowel wall in rectal cancer specimens.

DESIGN

This was a secondary analysis of data from a prospective phase II study.

SETTING

This study was performed in a multi-institutional setting.

PATIENTS

Included were 153 patients with stage II or stage III rectal cancer.

INTERVENTIONS

Patients were treated with chemoradiation and surgery. The surgical specimen tumor tissue was analyzed, and the distribution of residual cancer cells in each layer of the bowel wall was determined.

MAIN OUTCOME MEASURES

Statistical analysis was used to examine the correlation of residual cancer cells in each layer of the bowel wall with the clinical/pathologic stage and tumor regression grade.

RESULTS

Forty-two of 153 (27%) patients had complete response in the bowel wall (ypT0). Of the remaining 111 patients who had residual cancer cells, 5 (3%) were ypTis, 12 (8%) were ypT1, 41 (27%) were ypT2, 50 (33%) were ypT3, and 3 (2%) were ypT4. Of the 94 patients with ypT2-4 tumors, 12 (13%) had cancer cells in the mucosa, and 53 (56%) had cancer cells in the submucosa; 92 (98%) had cancer cells in the muscularis propria. Pretreatment cT correlated with the distribution of residual cancer cells. Tumor regression grade was not associated with the distribution of residual cancer cells after chemoradiation.

LIMITATIONS

: Patients received different chemotherapy regimens.

CONCLUSIONS

Residual cancer cells in rectal cancer specimens after chemoradiation are preferentially located close to the invasive front. This should be considered when designing strategies to diagnose complete pathologic response and when investigating the mechanisms of tumor resistance to chemoradiation.

Update and debate issues in surgical treatment of middle and low rectal cancer

Based on a review of the literature, this paper provides an update on surgical treatment of middle and low rectal cancer and discusses issues of debate surrounding that treatment. The main goal of the surgical treatment of rectal cancer is radical resection of the tumor and surrounding lymphatic tissue. Local excision of early rectal cancer can be another treatment option, in which the patient can avoid possible complications related to radical surgery. Neoadjuvant chemoradiation therapy (CRT) has been recommended for patients with cT3-4N0 or any T N+ rectal cancer because CRT shows better local control and less toxicity than adjuvant CRT. However, recent clinical trials showed promising results for local excision after neoadjuvant CRT in selected patients with low rectal cancer. In addition, the "wait and see" concept is another modality that has been reported for the management of tumors that show complete clinical remission after neoadjuvant CRT. Although radical surgery for middle and low rectal cancer is the cornerstone therapy, an ultralow anterior resection with or without intersphincteric resection (ISR) has become an alternative standard surgical method for selected patients. Many studies have reported on the oncological safety of the ISR, but few of them have addressed the issue the functional outcome. Furthermore, an abdominoperineal resection (APR) has problems with high rates of tumor perforations and positive circumferential resection margins, and those factors have contributed to its having a high rate of local recurrence and a poor survival rate for rectal cancer compared with sphincter-saving procedures. Recently, great efforts have been made to reduce these problems, and the total levator excision or the extended APR concept has emerged. Surgical management for low rectal cancer should aim to radically excise the tumor and to preserve as much of the sphincter function as possible by using multidisciplinary approaches. However, further prospective clinical trials are needed for tailored treatment of rectal cancer patients.

Oncologic outcome after preoperative chemoradiotherapy in patients with pathologic T0 (ypT0) rectal cancer

BACKGROUND

Little is known about the oncologic outcomes of patients with ypT0 rectal cancer after preoperative chemoradiotherapy.

OBJECTIVE

To evaluate the clinicopathologic characteristics and oncologic outcomes of patients with ypT0 rectal cancer after preoperative chemoradiotherapy and curative radical surgery.

DESIGN AND SETTINGS

This was a retrospective review of factors influencing outcome of patients treated with preoperative chemoradiotherapy for rectal cancer at a tertiary care university medical center in Seoul, Korea between 2000 and 2008.

PATIENTS

A total of 830 rectal cancer patients underwent surgery after preoperative chemoradiotherapy. Patients were included in the study if they had a pretreatment clinical classification of T3-4 or N+ (or T2N0 and preoperative chemoradiotherapy for sphincter preservation) and if they were classified on pathologic examination as ypT0 after preoperative CRT and curative radical surgery. Patients were classified as.

MAIN OUTCOME MEASURES

Overall survival and disease-free survival were evaluated in relation to ypT0N0 or ypT0N1-2 status and other factors that might influence outcome.

RESULTS

Of 91 patients included in the study, 54 (59.3%) were men; the mean patient age was 55 (SD, 11) years, and mean follow-up duration was 44 (SD, 23) months. Surgical procedures included low anterior resection in 68 patients, abdominoperineal resection in 21, and intersphincteric resection in 2. Mean tumor distance from the anal verge was 4.7 (SD, 1.8) cm. Of the 91 patients, 85 were classified as ypT0N0 and 6 as ypT0N1-2. No patient experienced local recurrence. A total of 11 patients (12.1%) had distant metastases, after a mean 11.1 months, including 7 (8.2%) with ypT0N0 and 4 (66.7%) with ypT0N1-2 tumors. One patient with ypT0N0 and 2 patients with ypT0N1-2 tumors died of metastasis. In patients classified as ypT0N0, the 5-year disease free survival and overall survival rates were 82.3% and 89.2%, respectively. Multivariate analysis showed that ypN1-2 status (p = 0.001) was a significant independent risk factor for recurrence (decreased 5-year disease-free survival), but no factor was associated with 5-year overall survival.

LIMITATIONS

The study is limited by its retrospective nature.

CONCLUSION

Oncologic outcomes in patients with ypT0N0 rectal cancer were excellent. The presence of residual cancer cells in mesorectal lymph nodes represents a risk factor for distant metastasis.

Preoperative versus postoperative radiotherapy for rectal cancer in a decision analysis and outcome prediction model

PURPOSE

Reduction of local recurrences has been achieved by radiotherapy, but also by improved surgical technique (total mesorectal excision). Radiotherapy has adverse effects and cannot exceed local dose limits. Neoadjuvant radiotherapy may result in overtreatment. We aimed to define the minimum local benefit that would have to be postulated for radiotherapy in order to bring a benefit to the overall cohort. We hypothesized that saving radiotherapy as treatment for a subset of patients with high-risk tumors and local recurrences improves the outcome of the overall cohort. We sought to simulate preoperative versus postoperative radiotherapy in theoretical decision analysis model based on published recurrence rates, with overall survival being the primary end point.

METHODS

Computerized literature search for studies published between 1996 and 2011, supplemented by manual review of the retrieved reference lists.

RESULTS

Postoperative radiotherapy evolved as preferred strategy with cure rates of 65.6 % vs. 63.7 % for postoperative and neoadjuvant radiotherapy, respectively, and a decrease of radiation exposure to 42.9 % of the cohort. The system was sensitive to (1) the fraction of stage I cancers included in the cohort, (2) the difference between local recurrence rates (LRR) for neoadjuvant radiotherapy, adjuvant radiotherapy, or surgery-only approach, and (3) the compliance with the postoperative radiotherapy. If the surgery-only recurrence was set to the published 10 %, 13 %, and 27 %, respectively, adjuvant radiotherapy had to achieve LRR below the threshold values of 6.3 %, 8.5 %, and 18.3 % to reverse the impact of compliance.

CONCLUSIONS

Radiotherapy only improves cancer-specific survival of the cohort if there is a large difference in LRR with versus without it. Routine treatment may therefore be inferior to a tailored radiotherapy regimen.

Critical appraisal of the 'wait and see' approach in rectal cancer for clinical complete responders after chemoradiation

BACKGROUND

Some 10-20 per cent of patients with locally advanced rectal cancer achieve a pathological complete response (pCR) at surgery following preoperative chemoradiation (CRT). Some demonstrate a sustained clinical complete response (cCR), defined as absence of clinically detectable residual tumour after CRT, and do not undergo resection. The aim of this review was to evaluate non-operative treatment of rectal cancer after CRT, and the outcome of patients observed without radical surgery.

METHODS

A systematic computerized search identified 30 publications (9 series, 650 patients) evaluating a non-operative approach after CRT. Original data were extracted and tabulated, and study quality evaluated. The primary outcome measure was cCR. Secondary outcome measures included locoregional failure rate, disease-free survival and overall survival.

RESULTS

The most recent Habr-Gama series reported a low locoregional failure rate of 4·6 per cent, with 5-year overall and disease-free survival rates of 96 and 72 per cent respectively. These findings were supported by a small prospective Dutch study. However, other retrospective series have described higher recurrence rates. All studies were heterogeneous in staging, inclusion criteria, study design and rigour of follow-up after CRT, which might explain the different outcomes. The definition of cCR was inconsistent, with only partial concordance with pCR. The results suggested that patients who are observed, but subsequently fail to sustain a cCR, may fare worse than those who undergo immediate tumour resection.

CONCLUSION

The rationale of a 'wait and see' policy relies mainly on retrospective observations from a single series. Proof of principle in small low rectal cancers, where clinical assessment is easy, should not be extrapolated uncritically to more advanced cancers where nodal involvement is common. Long-term prospective observational studies with more uniform inclusion criteria are required to evaluate the risk versus benefit.

Complete pathologic response after combined modality treatment for rectal cancer and long-term survival: a meta-analysis

BACKGROUND

Complete pathologic response (CPR) after neoadjuvant chemoradiotherapy (combined modality treatment, CMT) for rectal cancer seems associated with improved survival compared to partial or no response (NPR). However, previous reports have been limited by small sample size and single-institution design.

METHODS

A systematic literature review was conducted to detect studies comparing long-term results of patients with CPR and NPR after CMT for rectal cancer. Variables were pooled only if evaluated by 3 or more studies. Study end points included rates of CPR, local recurrence (LR), distant recurrence (DR), 5-year overall survival (OS), and disease-free survival (DFS).

RESULTS

Twelve studies (1,913 patients) with rectal cancer treated with CMT were included. CPR was observed in 300 patients (15.6%). CPR and NPR patient groups were similar with respect to age, sex, tumor size, distance of tumor from the anus, and stage of disease before treatment. Median follow-up ranged from 23 to 46 months. CPR patients had lower rates of LR [0.7% vs. 2.6%; odds ratio (OR) 0.45, 95% confidence interval (CI) 0.22-0.90, P = 0.03], DR (5.3% vs. 24.1%; OR 0.15, 95% CI 0.07-0.31, P = 0.0001), and simultaneous LR + DR (0.7% vs. 4.8%; OR 0.32, 95% CI 0.13-0.79, P = 0.01). OS was 92.9% for CPR versus 73.4% for NPR (OR 3.6, 95% CI 1.84-7.22, P = 0.002), and DFS was 86.9% versus 63.9% (OR 3.53, 95% CI 1.62-7.72, P = 0.002).

CONCLUSIONS

CPR after CMT for rectal cancer is associated with improved local and distal control as well as better OS and DFS.

Systematic review and meta-analysis of outcomes following pathological complete response to neoadjuvant chemoradiotherapy for rectal cancer

BACKGROUND

Following neoadjuvant chemoradiotherapy (CRT) and interval proctectomy, 15-20 per cent of patients are found to have a pathological complete response (pCR) to combined multimodal therapy, but controversy persists about whether this yields a survival benefit. This systematic review evaluated current evidence regarding long-term oncological outcomes in patients found to have a pCR to neoadjuvant CRT.

METHODS

Three major databases (PubMed, MEDLINE and the Cochrane Library) were searched. The systematic review included all original articles reporting long-term outcomes in patients with rectal cancer who had a pCR to neoadjuvant CRT, published in English, from January 1950 to March 2011.

RESULTS

A total of 724 studies were identified for screening. After applying inclusion and exclusion criteria, 16 studies involving 3363 patients (1263 with pCR and 2100 without) were included (mean age 60 years, 65·0 per cent men). Some 73·4 per cent had a sphincter-saving procedure. Mean follow-up was 55·5 (range 40-87) months. For patients with a pCR, the weighted mean local recurrence rate was 0·7 (range 0-2·6) per cent. Distant failure was observed in 8·7 per cent. Five-year overall and disease-free survival rates were 90·2 and 87·0 per cent respectively. Compared with non-responders, a pCR was associated with fewer local recurrences (odds ratio (OR) 0·25; P = 0·002) and less frequent distant failure (OR 0·23; P < 0·001), with a greater likelihood of being alive (OR 3·28; P = 0·001) and disease-free (OR 4·33, P < 0·001) at 5 years.

CONCLUSION

A pCR following neoadjuvant CRT is associated with excellent long-term survival, with low rates of local recurrence and distant failure.

Clinically relevant study end points in rectal cancer

In rectal cancer currently there are no clearly validated early end points which can serve as surrogates for long-term clinical outcome such as local control and survival. However, the use of a variety of response rates (i.e. pathological complete response, downsizing the primary tumor, tumor regression grade (TRG), radiological response) as endpoints in early (phase II) clinical trials is common since objective response to therapy is an early indication of activity. Disease-free survival (DFS) has been proposed as the most appropriate end point in adjuvant trials and is one of the most frequently used in newer rectal cancer trials. Due to the devastating nature of local recurrence in locally advanced rectal cancer, local control (which is itself a subset of the overall DFS endpoint) is still considered an important endpoint. Recently, circumferential resection margin (CRM) has been proposed as novel early end point because the CRM status can account for effects on DFS and overall survival after chemoradiation, radiation (RT), or surgery alone. Consensus is needed to define the most appropriate end points in both early and phase III trials in locally advanced cancer.

Posttherapy nodal status, not graded histologic response, predicts survival after neoadjuvant chemotherapy for advanced gastric cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) has been attempted as a means of improving survival of potentially resectable advanced gastric cancer (AGC). In the course of exploring the most promising NAC regimen, a superior surrogate marker reflecting overall survival (OS) is necessary. We investigated prognostic factors in AGC patients who underwent NAC followed by gastric resection and evaluated whether histologic response to NAC was predictive of survival.

METHODS

Seventy consecutive patients with gastric cancer treated with NAC followed by surgical resection between Jan 1, 2000, and Dec 31, 2009, at Osaka National Hospital were identified from a prospective database. Prognostic factors for OS were investigated by univariate and multivariate analyses.

RESULTS

Median survival time for all patients was 668 days after surgical resection. Age less than 65 years (hazard ratio 0.463, 95% confidence interval 0.244-0.879) and pathologic nodal stage of N0-1 (hazard ratio 0.318, 95% confidence interval 0.160-0.635) were identified as significant independent prognostic factors for longer OS, whereas graded histologic response of primary tumor to NAC was statistically significant on univariate analysis, but not on multivariate analysis, as a prognostic factor.

CONCLUSIONS

Posttherapy nodal status, not graded histologic response, predicts survival after NAC for AGC and could serve as a reliable surrogate marker for OS in the course of exploring the most promising regimen for NAC.

Can mesorectal lymph node excision be avoided in rectal cancer surgery?

Rectal excision is the standard in rectal cancer treatment. The morbidity of rectal excision, together with the low rate of positive lymph nodes in patients with a good response after radiochemotherapy, raises the challenging concept of organ preservation. Patients with a complete response can benefit from a nonoperative strategy based on a strict follow up. Those with a complete or subcomplete response can be treated by local excision. Limitations in accurately assessing a complete response by conventional and modern imaging modalities suggest that local excision is more appropriate for the majority of patients when organ preservation is being considered. The encouraging results of retrospective series of local excision in downstaged clinical T2/T3 low rectal cancer after radiochemotherapy, however, need to be confirmed by the ongoing multicentre phase II United States and phase III French trials before routinely proposing organ preservation in patients with a good response.

Pathologic complete response after neoadjuvant treatment for rectal cancer decreases distant recurrence and could eradicate local recurrence

BACKGROUND

The aim of this study was to evaluate the clinical implications of pathologic complete response (pCR) (i.e., T0N0M0) after neoadjuvant chemoradiation and radical surgery in patients with locally advanced rectal cancer.

MATERIALS AND METHODS

A single-center, prospectively maintained colorectal cancer database was queried for patients with primary cII and cIII rectal cancer staged by CT and ERUS/MRI undergoing long-course neoadjuvant chemoradiation followed by proctectomy with curative intent between 1997 and 2007. Patients were stratified into pCR and no-pCR groups and compared with respect to demographics, tumor and treatment characteristics, and oncologic outcomes. Outcomes evaluated were 5-year overall survival, disease-free survival, disease-specific mortality, local recurrence, and distant recurrence.

RESULTS

The query returned 238 patients (73% male), with a median age of 57 years and median follow-up of 54 months. Of these, 58 patients achieved pCR. Patients with pCR vs no-pCR were statistically comparable with respect to demographics, chemoradiation regimens, tumor distance from anal verge, clinical stage, surgical procedures performed, and follow-up time. No patient with pCR had local recurrence. Overall survival and distant recurrence were also significantly improved for patients achieving pCR.

CONCLUSIONS

Achievement of pCR after neoadjuvant chemoradiation is associated with greatly improved cancer outcomes in locally advanced rectal cancer. Future studies should evaluate the relationship between increases in pCR rates and improvements in cancer outcomes in this population.

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

PURPOSE

Neoadjuvant chemoradiation followed by surgery is now the standard of care for patients with locally advanced rectal cancers. The aim of this study was to determine the rate of pathological complete response (pCR) following neoadjuvant treatment in patients with rectal cancers and identify the factors predicting the same.

METHODS

We conducted a retrospective analysis of patients with rectal cancers treated with neoadjuvant therapy followed by surgery at our institution from 1993 to 2008. Patients who achieved pCR were identified. Various patient, tumor, and treatment-related factors were studied for their influence on pCR by univariate and multivariate analyses. The influence of pCR on survival was also studied but was restricted to patients with a minimum follow-up of 5 years.

RESULTS

Between 1993 and 2008, 248 patients with rectal cancers received neoadjuvant therapy followed by surgery. Two hundred and twenty-seven patients received chemoradiation and 21 patients received only radiation. Pathological complete response was seen in 32 patients (12.9%). On multivariate analysis, the factors found to be independently predictive of pathological response were circumferential extent of the primary tumor (p = 0.016) and signet ring cell histology (p = 0.001). Among 116 patients with a minimum follow-up of 5 years, there was a trend towards increased overall survival (75% versus 54%) and reduced local recurrence (6.2% versus 12.3%) in the 16 patients who achieved a pCR compared to those who did not, even though the difference was not statistically significant.

CONCLUSIONS

The factors that predict a pCR after neoadjuvant treatment for rectal cancers are absence of circumferential involvement and signet ring cell histology. Pathological complete response may confer an insignificant survival advantage.

Is local excision after complete pathological response to neoadjuvant chemoradiation for rectal cancer an acceptable treatment option?

PURPOSE

The role of local excision in patients with good histological response to neoadjuvant chemoradiation for locally advanced rectal cancer is unclear, mainly because of possible regional nodal involvement. This study aims to evaluate the correlation between pathological T and N stages following neoadjuvant chemoradiation for locally advanced rectal cancer and the outcome of patients with mural pathological complete response undergoing local excision.

METHODS

This investigation was conducted as a retrospective analysis. Between January 1997 and December 2007, 320 patients with T3 to 4Nx, TxN+ or distal (≤ 6 cm from the anus) T2N0 rectal cancer underwent neoadjuvant concurrent chemoradiation followed by surgery. Radiotherapy was standard and chemotherapy consisted of common fluoropyrimidine-based regimens.

RESULTS

After chemoradiation, 93% patients had radical surgery, 6% had local excision, and 3% did not have surgery. In the 291 patients undergoing radical surgery, the pathological T stage correlated with the N stage (P = .036). We compared the outcome of patients with mural complete pathological response (n = 37) who underwent radical surgery (group I) and those (n = 14) who had local excision only (group II). With a median follow-up of 48 months, 4 patients in group I had a recurrence and none in group II had a recurrence; one patient died in group I and none died in group II. Disease-free survival, pelvic recurrence-free survival, and overall survival rates were similar in both groups.

CONCLUSION

In this retrospective study, nodal metastases were rare in patients with mural complete pathological response following neoadjuvant chemoradiation (3%), and local excision did not compromise their outcome. Therefore, local excision may be an acceptable option in these patients.

Outcome standards for an organ preservation strategy in stage II and III rectal adenocarcinoma after neoadjuvant chemoradiation

BACKGROUND

Neoadjuvant chemoradiotherapy is the standard of care for patients with locally advanced mid and distal rectal cancer. Tumor regression is variable, and this study was designed to evaluate the pathological response and impact on long-term disease control in responders and nonresponders.

METHODS

A total of 303 consecutive patients with cStage II and III mid and distal rectal adenocarcinoma were identified. The mean age was 64 years and 63% were men. Patients received neoadjuvant chemoradiotherapy (45 Gy) with a continuous infusion of 5-fluorouracil. Total mesorectal excision (TME) was performed after an interval of 6-8 weeks. Tumors were stratified as responders (ypT0 or ypT1) and nonresponders (≥ypT3). All ypT2 were separately categorized.

RESULTS

Tumors of 84 patients were classified as responders (27.5%) versus nonresponders in 144 patients (47.5%). Pathological tumor stage was ypT2 in 75 patients (25%). After a median follow-up of 55 months, the 5-year cancer-specific survival rate was 98% and the disease-free survival rate was 91% in responders versus 82% (P < 0.0025) and 60% (P < 0.0001), respectively, for the nonresponders.

CONCLUSIONS

After neoadjuvant chemoradiotherapy and TME surgery for locally advanced rectal cancer and complete or near-complete pathological tumor response oncological outcome is very good. These results set the standards for a rectum-sparing strategy.

Long-term outcome in patients with a pathological complete response after chemoradiation for rectal cancer: a pooled analysis of individual patient data

BACKGROUND

Locally advanced rectal cancer is usually treated with preoperative chemoradiation. After chemoradiation and surgery, 15-27% of the patients have no residual viable tumour at pathological examination, a pathological complete response (pCR). This study established whether patients with pCR have better long-term outcome than do those without pCR.

METHODS

In PubMed, Medline, and Embase we identified 27 articles, based on 17 different datasets, for long-term outcome of patients with and without pCR. 14 investigators agreed to provide individual patient data. All patients underwent chemoradiation and total mesorectal excision. Primary outcome was 5-year disease-free survival. Kaplan-Meier survival functions were computed and hazard ratios (HRs) calculated, with the Cox proportional hazards model. Subgroup analyses were done to test for effect modification by other predicting factors. Interstudy heterogeneity was assessed for disease-free survival and overall survival with forest plots and the Q test.

FINDINGS

484 of 3105 included patients had a pCR. Median follow-up for all patients was 48 months (range 0-277). 5-year crude disease-free survival was 83.3% (95% CI 78.8-87.0) for patients with pCR (61/419 patients had disease recurrence) and 65.6% (63.6-68.0) for those without pCR (747/2263; HR 0.44, 95% CI 0.34-0.57; p<0.0001). The Q test and forest plots did not suggest significant interstudy variation. The adjusted HR for pCR for failure was 0.54 (95% CI 0.40-0.73), indicating that patients with pCR had a significantly increased probability of disease-free survival. The adjusted HR for disease-free survival for administration of adjuvant chemotherapy was 0.91 (95% CI 0.73-1.12). The effect of pCR on disease-free survival was not modified by other prognostic factors.

INTERPRETATION

Patients with pCR after chemoradiation have better long-term outcome than do those without pCR. pCR might be indicative of a prognostically favourable biological tumour profile with less propensity for local or distant recurrence and improved survival.

FUNDING

None.

Could a wait and see policy be justified in T3/4 rectal cancers after chemo-radiotherapy?

Chemoradiotherapy (CRT) followed by total mesorectal excision is the standard when MRI staging demonstrates threatened surgical margins in locally advanced rectal cancer (LARC). Interest in non-surgical management of LARC as an alternative to a resection has been provoked by published excellent long-term outcomes of patients who achieve clinical complete responses (cCR) after CRT. The present retrospective study aimed to determine whether similar rates of local disease control are seen in a UK cancer centre in patients with T3-4 tumours, who obtained a cCR after preoperative CRT, but did not undergo surgery.

METHOD

The outcome and treatment details of 266 patients who underwent CRT for clinically staged T3-4 rectal adenocarcinomas between 1993 and 2005 were reviewed.

RESULTS

Fifty-eight patients did not proceed to surgery, 10 of whom were identified as having a cCR. Six of these 10 patients subsequently developed intrapelvic recurrent disease with a median time to local progression of 20 months. Local relapse preceded the development of metastatic disease or occurred simultaneously. No patients underwent salvage resection.

CONCLUSION

CRT alone in cT3/T4 rectal cancers has a high rate of local relapse even after cCR. Delaying or avoiding surgery might be appropriate for cT1 or cT2 tumours, or elderly and frail patients with co-morbidity, but these results do not support the current uncritical move to extrapolate this approach to all surgically fit patients with rectal cancer.

Downstaging after chemoradiotherapy for locally advanced rectal cancer: is there more (tumor) than meets the eye?

PURPOSE

Preoperative chemoradiotherapy can lead to pathologic complete response of rectal cancer. This study was designed to determine the relationship between postchemoradiotherapy pathologic T stage (ypT stage) and nodal metastases and to evaluate whether pathologic complete response of the primary tumor results in sterilization of mesorectal lymph nodes.

METHODS

Clinicopathological data from 1997 to 2007 of a prospectively maintained colorectal cancer database were examined. Inclusion criteria were patients with extraperitoneal rectal cancer who underwent preoperative chemoradiotherapy and subsequent radical resection. Statistical analysis was performed by use of Kruskall-Wallis and Wilcoxon rank-sum tests.

RESULTS

Two hundred forty-two patients were identified (73.1% male, median age, 57 y (range, 36-85 y)). Data regarding preoperative chemoradiotherapy were available for 177 patients (73.1%). The median dose of radiotherapy was 5040 cGy (3060-6100 cGy). The mean preoperative radiotherapy dose and interval between chemoradiotherapy and surgery are similar when stratified by ypT stage (P = .55 and P = .72, respectively). Low anterior resection was performed in 174 patients (71.6%), and the remainder underwent abdominoperineal resection. A mural pathologic complete response was achieved in 62 patients (25.6%). In this pathologic complete-response group, positive lymph nodes were found in 2 patients (3.2%). The rate of metastatic lymph nodes increased as ypT stage increased (ypT1 = 11.1%, ypT2 = 29.2%, ypT3 = 37.3%).

CONCLUSION

Patients with a mural pathologic complete response have a low rate of positive lymph nodes. These findings may have implications for the management strategies of these patients, including the use of local resection or a watch-and-wait policy. When the response to chemoradiotherapy is not complete, radical surgery should remain the treatment based on high rates of lymph node involvement.

Clinical significance of acellular mucin in rectal adenocarcinoma patients with a pathologic complete response to preoperative chemoradiation

OBJECTIVE

The objective of this study was to determine the prevalence and prognostic significance of acellular mucin within resected specimens of rectal cancer patients with a pCR following preoperative chemoradiation.

SUMMARY BACKGROUND DATA

The presence of acellular mucin pools in the resected specimens of patients with a complete response to preoperative chemoradiation is frequently reported as a marker of treatment effect. The clinical significance of the presence of acellular mucin with respect to local recurrence and survival outcomes is unknown.

METHODS

Data from a rectal cancer database was used to analyze 562 patients with nonmetastatic rectal adenocarcinoma treated between 1989 and 2004. The presence or absence of acellular mucin within the specimen was identified by the surgical pathology reports and confirmed by re-examination of H&E sections of surgical specimens.

RESULTS

Among the 562 patients, 100 patients (18%) had pCR. Acellular mucin was present in 27 (27%) of the 100 patients with pCR. The median follow-up interval was 87 months (range, 1-198 months). Local and distant failures occurred in 0 and 2 patients with acellular mucin, and in 1 and 6 patients without acellular mucin, respectively. The actuarial 7-year overall survival rates were 85% for patients with acellular mucin and 92% for patients without acellular mucin (P = 0.954). The actuarial 7-year disease-free survival rates were 81% and 87% (P = 0.764) and the 7-year freedom from relapse rates were 93% and 91% (P = 0.881) in patients with and without acellular mucin, respectively.

CONCLUSIONS

Acellular mucin is present within 27% of resected specimens in rectal cancer patients with a pCR after preoperative chemoradiation. However, the presence of acellular mucin has no prognostic significance.

Postoperative chemotherapy after neoadjuvant chemoradiation and surgery for rectal cancer: is it essential for patients with ypT0-2N0?

BACKGROUND

The potential advantage of adjuvant chemotherapy in patients with ypT0-2N0 rectal cancer remains unclear. The purpose of this study was to evaluate whether this therapy has an impact on survival.

MATERIALS AND METHODS

Patients who underwent curative surgery after preoperative chemoradiation for locally advanced low rectal cancer were retrospectively reviewed. A total of 41 consecutive patients with pathological stage 0 (ypT0N0) or I (ypT1-2N0) were enrolled. Of the 41 patients, 17 (41.5%) received postoperative 5-fluorouracil (5-FU)-based chemotherapy, while 24 were followed without postoperative therapy. Oncologic outcomes were compared between the two groups.

RESULTS

The median follow-up period was 47.6 months. The overall postoperative complication rates did not differ significantly between the patients who received chemotherapy and those who did not (17.6% vs. 20.8%, P = 0.799). The 5-year overall and disease-free survival rates for patients who received chemotherapy were 88.9% and 84.7%, which were not significantly different from the rates for those who did not (85.9%; P = 0.644 and 73.4%; P = 0.599, respectively).

CONCLUSIONS

Postoperative adjuvant chemotherapy for patients with good responses after preoperative chemoradiation and curative surgery did not significantly improve the survival. However, this should be validated in prospective randomized trials with larger sample sizes.