Preoperative staging of irradiated rectal cancers using digital rectal examination, computed tomography, endorectal ultrasound, and magnetic resonance imaging does not accurately predict T0,N0 pathology

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.

Complete radiotherapy response in rectal cancer: A review of the evidence

Complete response to chemoradiotherapy for rectal cancer is becoming a common clinical entity. Techniques to diagnose complete response and how to survey these patients without operative intervention are still unclear. We review the most recent evidence. Barriers to firm conclusions regarding this are heterogeneity of diagnostic definitions, differing surveillance protocols, and a lack of randomised studies.

Transanal Endoscopic Microsurgery After Neoadjuvant Chemoradiotherapy for Rectal Cancer

BACKGROUND

Radical rectal resection following neoadjuvant chemoradiation therapy (CRT) for locally advanced rectal cancer is accompanied by relatively high morbidity. Local excision of rectal cancer may be more appropriate for some frail patients with severe comorbidities. Transanal endoscopic microsurgery (TEM), consisting of local excision of selected rectal cancers, has been associated with low rates of postoperative complications. Because neoadjuvant CRT for rectal cancer may be associated with increased complications, the suitability of TEM following CRT is still unclear. In this study we aimed to assess the clinical outcomes of patients undergoing TEM following neoadjuvant CRT.

PATIENTS AND METHODS

This study retrospectively analyzed all patients undergoing TEM for malignant rectal tumor in our institution between 2004 and 2010. They were divided into those who received CRT (CRT group) and those without CRT (non-CRT group). Demographics and clinical data were compared.

RESULTS

Forty-four of 97 patients who underwent TEM were included: 13 CRT and 31 non-CRT. Age, comorbidities, and the duration of the procedure were similar for both groups. There were no significant group differences in tumor diameter (2.1 cm [range, 0.5-3.5 cm] and 2.9 cm [range, 0.5-4.2 cm], respectively; P=.125) or distance of the lower part of the tumor from the anal verge (6.7 cm [range, 5-10 cm] and 7.7 cm [range, 5-15 cm], respectively; P=.285). Two non-CRT patients had peritoneal entry, and 1 of them underwent protective ileostomy because of insecure rectal defect closure. One non-CRT patient underwent a re-operation for postoperative bleeding. The other perioperative complications were minor and included urinary retention requiring catheter placement (2 patients in each group), pulmonary edema (1 non-CRT patient), and pneumonia (1 non-CRT patient). All complications were managed conservatively. There was no wound disruption, major complication, or mortality in either group.

CONCLUSIONS

With proper patient selection, TEM can be performed safely following CRT, without major complication or increased postoperative morbidity.

Lymph node status as a prognostic indicator after preoperative neoadjuvant chemoradiotherapy of rectal cancer

AIM

The primary aim of this study was to examine lymph node status after neoadjuvant chemoradiotherapy (CRT) using a novel scoring system describing the pathological lymph node regression grade. The proposed scoring system was based on the percentage of fibrosis and the presence of residual tumour amount. The secondary aim of the study was to assess the oncological impact of this scoring system.

METHOD

The project was a retrospective cohort study over a 10-year period. Two hundred and two patients with rectal cancer who had received CRT followed by curative surgery were included. A histopathologist prospectively scored each specimen and the impact of the scoring system on survival and recurrence was analysed.

RESULTS

One hundred and ninety patients completed long-course preoperative CRT and formed the basis of the study. Overall, 40 recurrences (local and distant) were observed over a median follow-up of 36 months. The lymph node regression score was a significant predictor of tumour recurrence (hazard ratio 1.273, 95% CI 1.048-1.548; P = 0.015). The overall mortality rate was 21%, and a lower lymph node regression score was correlated with an improved survival curve (P = 0.01).

CONCLUSION

The results demonstrate that lymph node response to neoadjuvant CRT based on a nodal regression scoring system is related to recurrence.

Predictive value of (18)FDG PET-CT for tumour response in patients with locally advanced rectal cancer treated by preoperative chemoradiotherapy

PURPOSE

Although (18)fluorine-2-deoxy-D-glucose positron emission tomography-computed tomography ((18)FDG PET-CT) is considered a reliable modality for determining tumour response after neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC), the role of (18)FDG PET-CT for predicting pathologic complete response (pCR) remains unclear. The aim of this study was to evaluate whether (18)FDG PET-CT can predict tumour response after CRT in patients with LARC, in terms of downstaging and pCR.

METHODS

Between March 2009 and February 2012, 151 patients with LARC treated with neoadjuvant CRT followed by radical surgery were reviewed retrospectively. Pre-CRT SUVmax (maximum standardized uptake value), post-CRT SUVmax, ΔSUVmax (difference between pre- and post-CRT SUVmax), and RI-SUV (response index) were measured before and after CRT. Univariate and multivariate analyses were used to analyse the association of PET-CT-related parameters and clinical variables, to assess downstaging and pCR.

RESULTS

Downstaging occurred in 48 patients (31.7 %) and pCR in 19 patients (12.5 %). Univariate and multivariate analysis revealed post-CRT SUVmax as a significant factor for prediction of downstaging, with sensitivity of 60.4 %, specificity of 65.0 %, and accuracy of 55.9 %, for a cutoff value of 3.70. Regarding pCR, post-CRT SUVmax was again found as a significant parameter by univariate and multivariate analysis, with sensitivity of 73.7 %, specificity of 63.7 %, and accuracy of 64.9 %, for a cutoff value of 3.55.

CONCLUSIONS

The results indicate that post-CRT SUVmax independently predicts downstaging and pCR. However, the predictive values of post-CRT SUVmax for tumour response after neoadjuvant CRT are too low in sensitivity and specificity to change the treatment plan for LARC.

Long-term outcome of local excision after complete pathological response to neoadjuvant chemoradiation therapy for rectal cancer

BACKGROUND

Neoadjuvant chemoradiotion therapy (CRT) for advanced rectal cancer has improved local disease. Complete rectal wall tumor regression may be associated with the absence of viable cancer cells in the mesorectum, and thus local excision (LE) of such lesions as an alternative to radical surgery has recently gained interest. We report the long-term outcome of LE in patients with a mural pathological complete response (ypT0) after CRT.

METHODS

A retrospective review of patients with rectal cancer treated by CRT and followed by LE with pathological complete response in the specimen between 1998 and 2009 was performed.

RESULTS

A total of 174 patients had neoadjuvant CRT, and 68 (39 %) showed complete clinical response (cCR). Thirty-one of the cCR patients underwent LE; 23 of them resulted in ypT0 and 8 had residual disease. The ypT0 group included 12 men and 11 women with a median age of 66. The pretreatment stage was T3N1 in 4 (17 %) patients, T3N0 in 11 (48 %), T2N1 in 3 (13 %), and T2N0 in 5 (22 %). The median tumor distance from the anal verge was 6 cm. Sixteen patients (70 %) underwent transanal excision, and 7 (30 %) were treated by transanal-endoscopic microsurgery. Three patients died: one of pneumonia, one of melanoma of the rectum, and one of lung carcinoma. No local or distant recurrences were detected in the remaining 20 patients. The median follow-up was 87 months.

CONCLUSIONS

Although radical rectal resection is the treatment of choice, LE of complete rectal tumor regression could be a safe alternative with an acceptable result in selected patients.

Is the standardized uptake value of FDG-PET/CT predictive of pathological complete response in locally advanced rectal cancer treated with capecitabine-based neoadjuvant chemoradiation?

OBJECTIVES

Our aim was to assess FDG-PET/CT as a surrogate biomarker of the pathological complete response in locally advanced rectal cancer treated with neoadjuvant chemoradiation.

METHODS

T3-4 and/or N+ rectal cancer patients were treated prospectively with capecitabine-based chemoradiation and total mesorectal excision 7-8 weeks later. FDG-PET/CT uptake was obtained at baseline, after 2 weeks, and 6 weeks following treatment completion, calculating the maximum standardized uptake value (SUV) and percentage difference to identify the early and late metabolic 'response index'.

RESULTS

Thirty-one patients were treated from January 2009 to January 2012 at the Istituto Nazionale dei Tumori of Milan. One patient was excluded due to surgery refusal. The pathological complete response rate was 30%. Early FDG-PET/CT was performed in 24 consenting patients and failed to show predictive utility. On the contrary, significant differences in late SUV value and response index were observed between complete and noncomplete pathological responders (p = 0.0006 and 0.03). In multivariate analysis including most relevant SUV parameters, none of them was independently associated with a pathological complete response. With receiver operating characteristic curve analysis, a late SUV threshold <5.4 had 81% sensitivity and 100% specificity, with 90% overall accuracy.

CONCLUSIONS

We evidenced a possible predictive role of late FDG-PET/CT for the assessment of pathological response in locally advanced rectal cancer following neoadjuvant chemoradiation.

The predictive role of sequential FDG-PET/CT in response of locally advanced rectal cancer to neoadjuvant chemoradiation

PURPOSE

This study prospectively assessed the value of sequential fluorine-18-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) scans for predicting the response of locally advanced rectal cancer to neoadjuvant chemoradiation.

METHODS

Fifty consecutive patients with locally advanced rectal cancer were enrolled. The treatment consisted of concurrent chemoradiation, which included preoperative 5-fluorouracil-based chemotherapy and pelvic radiation (4500 to 5040 cGy); this was followed 8 weeks later (median: 55 d) by surgery with a curative intent. All the patients underwent FDG-PET/CT before and 5 weeks later (median: 35 d) after the completion of chemoradiation. We evaluated the measurements of the FDG uptake [maximum standardized uptake values (SUV(max))] and the percentage of SUV(max) difference [(response index (RI)] between the prechemoradiation and postchemoradiation FDG-PET/CT scans.

RESULTS

After chemoradiation, 32 of 50 patients (64%) were classified as responders according to the tumor regression grade, which is based on the ratio of fibrosis to residual cancer (tumor regression grade 3-4). For all the patients, the mean prechemoradiation SUV(max) was 14.8, and this was significantly higher than the mean SUV(max) value of 6.1 at postchemoradiation (P< 0.001). The mean RI was significantly higher in the responders than that in the nonresponder patients (62.6% vs. 31.2%, P = 0.001). The following parameters were obtained using a RI cutoff of 53.0% for defining a response to therapy: 75.0% sensitivity, 73.2% specificity, 82.8% positive predictive value, and 61.9% negative predictive value.

CONCLUSIONS

The FDG-PET/CT parameters, and especially the RI, may be best for assessing the neoadjuvant chemoradiation response of locally advanced rectal cancer and these values can potentially assist physicians for planning the optimal treatment.

Accuracy of transrectal ultrasound after preoperative radiochemotherapy compared to computed tomography and magnetic resonance in locally advanced rectal cancer

INTRODUCTION

The aim of the present study was to compare the restaging results obtained by transrectal ultrasound (TRUS), computed tomography (CT), and magnetic resonance imaging (MRI) performed after preoperative chemoradiation with pathologic staging of the operative specimen.

METHODS

From January 2008 to December 2009, all the consecutive patients with locally advanced rectal cancer that underwent neoadjuvant therapy at our department were evaluated. The results of diagnostic examinations and the definitive pathological examination were considered and compared.

RESULTS

Thirty-seven patients were included in the study (27 males, 73%), mean age was 65.5 years (range 45–82 years). In all the patients TRUS and CT and in 20 patients MRI were performed before and after the treatment. Concerning the depth of invasion after treatment TRUS agreed with histopathology in 25/37 patients (67.5%), CT agreed in 22/ 37 cases (59.5%), and MRI in 12/20 cases (60%). Considering only neoplasia with stage T3, TRUS agreed in 23/24 cases (96%), CT in 19 cases (79%), and MRI in 10/12 cases (83.5%). Considering the tumors that did not exceed the rectal wall (T0, T1, and T2), TRUS agreed with histology in 2/13 cases (15.5%),CTin 3/13 cases (23%), andMRI 2/8 cases (25%). Concerning the presence of positive lymph nodes TRUS agreed with histology in 28/37 cases (75.5%), while CT agreed in 21/37 cases (56.5%) and MRI in 11/20 cases (55%). The concordance between the techniques was found to be low.

CONCLUSIONS

Transrectal ultrasonography resulted as the most accurate method to determine neoplastic wall infiltration and lymph node involvement even after radiochemotherapy. In most cases, considering the poor correlation between the diagnostic procedures and the disagreement of the results, a restaging performed only with TRUS could be proposed, limiting the use of the other imaging methods to selected cases.

Predicting tumor response after preoperative chemoradiation using clinical parameters in rectal cancer

AIM: To evaluate the clinical parameters and identify a better method of predicting pathological complete response (pCR).

METHODS: We enrolled 249 patients from a database of 544 consecutive rectal cancer patients who underwent surgical resection after preoperative chemoradiation therapy (PCRT). A retrospective review of morphological characteristics was then performed to collect data regarding rectal examination findings. A scoring model to predict pCR was then created. To validate the ability of the scoring model to predict complete regression.

RESULTS: Seventy patients (12.9%) achieved a pCR. A multivariate analysis found that pre-CRT movability (P = 0.024), post-CRT size (P = 0.018), post-CRT morphology (P = 0.023), and gross change (P = 0.009) were independent predictors of pCR. The accuracy of the scoring model was 76.8% for predicting pCR with the threshold set at 4.5. In the validation set, the accuracy was 86.7%.

CONCLUSION: Gross changes and morphological findings are important predictors of pathological response. Accordingly, PCRT response is best predicted by a combination of clinical, laboratory and metabolic information.

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.

Accuracy of endoscopic ultrasound in staging and restaging patients with locally advanced rectal cancer undergoing neoadjuvant chemoradiation

BACKGROUND

To date, the role of endoscopic ultrasound (EUS) in restaging locally advanced rectal cancer (LARC) after neoadjuvant chemoradiotherapy (NAT) have not been thoroughly investigated.

AIM

To evaluate accuracy and clinical usefulness of EUS for both staging and restaging LARC.

METHODS

According to EUS staging, patients with LARC were enrolled in the study. Those who underwent surgery directly represented a control group useful for evaluating the accuracy of EUS in staging LARC. In the study group, EUS was repeated seven weeks after NAT, before surgery. The results of EUS were compared with the corresponding pTN stages.

RESULTS

From 2000 to 2006, 212 consecutive patients with RC underwent EUS staging. Among them EUS diagnosed 162 LARC (M/F = 93/69; mean age: 60 years [range 40-80]). The final study group included 85 patients with LARC. EUS restaging had an overall accuracy of 61% and 59% for T and N-stage, respectively. In the control group, the accuracy of EUS in staging LARC was 86% and 58% for T and N-stage, respectively.

CONCLUSION

EUS accurately stages LARC and enables appropriate decision-making, with selection of those patients who need NAT. On the other hand, EUS restaging of LARC after NAT has low accuracy and should not be used in clinical practice.

FDG PET and PET/CT for colorectal cancer

The evaluation of patients with known or suspected recurrent colorectal carcinoma is now an accepted indication for positron emission tomography using (18)F-fluorodeoxyglucose (FDG-PET) imaging. PET and CT are complimentary, and therefore, integrated PET/CT imaging should be performed where available. FDG-PET/CT is indicated as the initial test for diagnosis and staging of recurrence, and for preoperative staging (N and M) of known recurrence that is considered to be resectable. FDG-PET imaging is valuable for the differentiation of posttreatment changes from recurrent tumor, differentiation of benign from malignant lesions (indeterminate lymph nodes, hepatic, and pulmonary lesions), and the evaluation of patients with rising tumor markers in the absence of a known source. The addition of FDG-PET/CT to the evaluation of these patients reduces overall treatment costs by accurately identifying patients who will and will not benefit from surgical procedures. This new powerful technology provides more accurate interpretation of both CT and FDG-PET images and therefore more optimal patient care. PET/CT fusion images affect the clinical management by guiding further procedures (biopsy, surgery, and radiation therapy), excluding the need for additional procedures, and changing both inter- and intramodality therapy.

Patterns of response after preoperative intensity-modulated radiation therapy and capecitabine/oxaliplatin in rectal cancer: is there still a place for ecoendoscopic ultrasound?

PURPOSE

The main goals of preoperative chemoradiotherapy (CHRT) in rectal cancer are to achieve pathological response and to ensure tumor control with functional surgery when possible. Assessment of the concordance between clinical and pathological responses is necessary to make decisions regarding alternative conservative procedures. The present study evaluates the patterns of response after a preoperative CHRT regimen, and the value of endoscopic ultrasound (EUS) in assessing response.

METHODS AND MATERIALS

A total of 51 EUS-staged T3 to T4 and/or N0 to N+ rectal cancer patients received preoperative CHRT (intensity-modulated radiation therapy and capecitabine/oxaliplatin (XELOX) followed by radical resection. Clinical response was assesed by EUS. Rates of pathological tumor regression grade (TRG) and lymph node (LN) involvement were determined in the surgical specimen. Clinical and pathological responses were compared, and the accuracy of EUS in assessing response was calculated.

RESULTS

Twenty-four patients (45%) achieved a major pathological response (complete or >95% pathological response (TRG 3+/4)). Sensitivity, specificity, negative predictive value, and positive predictive value of EUS in predicting pathological T response after preoperative CHRT were 77.8%, 37.5%, 60%, and 58%, respectively. The EUS sensitivity, specificity, negative predictive value, and positive predictive value for nodal staging were 44%, 88%, 88%, and 44%, respectively. Furthermore, EUS after CHRT accurately predicted the absence of LN involvement in 7 of 7 patients (100%) with major pathological response of the primary tumor.

CONCLUSION

Preoperative IMRT with concomitant XELOX induces favorable rates of major pathological response. EUS has a limited ability to predict primary tumor response after preoperative CHRT, but it is useful for accurately determining LN status. EUS may have a potential value in identifying patients with a very low risk of LN involvement in association with a good pathological response as potential candidates for conservative local surgical protocols.

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.

Locally advanced rectal cancer: MR imaging for restaging after neoadjuvant radiation therapy with concomitant chemotherapy. Part I. Are we able to predict tumor confined to the rectal wall?

PURPOSE

To retrospectively assess accuracy of magnetic resonance (MR) imaging after radiation therapy with concomitant chemotherapy for downsizing of the primary lesion to ypT0-2 tumor confined to rectal wall in locally advanced rectal cancer, with histopathologic findings as reference standard, and to evaluate additional value of volumetric analysis.

MATERIALS AND METHODS

The institutional review board approved the study and waived informed consent. Sixty-seven patients met criteria of the study. T2-weighted MR images obtained before and after radiation therapy with concomitant chemotherapy were assessed for tumor stage by expert abdominal radiologist, colorectal surgeon, and general radiologist. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated; tumor volume was measured (compared with Mann-Whitney U test). Findings were correlated with histopathologic findings.

RESULTS

Sixty-seven patients (38 men, 29 women; mean age, 63 years) who underwent radiation therapy with concomitant chemotherapy and surgery (all but one) were evaluated. The PPV for prediction of tumor confined to rectal wall (ypT0-2) was 91% (10 of 11), 86% (six of seven), and 88% (seven of eight) for expert abdominal radiologist, surgeon, and general radiologist, respectively. In 24 patients, sensitivity was 42% (10), 25% (six), and 29% (seven). ypT0-2 tumors had significantly smaller volumes than did ypT3-4 tumors before radiation therapy with concomitant chemotherapy (55 vs 92 cm(3), P = .038). Volume reduction rates were significantly higher in ypT0-2 than in ypT3-4 tumors (89% vs 61%, P < .001). If volume before radiation therapy with concomitant chemotherapy was 50 cm(3) or smaller and volume reduction rate was 75% or higher, excised tumor was always confined to rectal wall (ypT0-2). By using these criteria, 43% (six of 14) of cases with overstaging could have been predicted to be ypT0-2 tumors correctly.

CONCLUSION

Downsizing to ypT0-2 tumors can be accurately predicted by combining morphologic tumor staging predictions with results from volumetric analyses. MR images obtained after radiation therapy with concomitant chemotherapy might be helpful in more individualized treatment planning.

Preoperative radiotherapy and local excision of rectal cancer with immediate radical re-operation for poor responders

BACKGROUND AND PURPOSE

To report an early analysis of prospective study exploring preoperative radiotherapy and local excision in rectal cancer.

MATERIALS AND METHODS

Mucosa at tumour edges was tattooed. Patients with cT1-3N0 tumour <3-4 cm were treated with either 5x5Gy+4Gy boost (N=31) or chemoradiation (50.4Gy+5.4Gy boost, 1.8Gy per fraction+5-fluorouracyl and leucovorin; N=13). Thirteen patients from the short-course group were unfit for chemotherapy. The interval from radiation to full-thickness local excision was 6 weeks. The protocol called for conversion to a transabdominal surgery in case of ypT2-3 disease or positive margin.

RESULTS

The postoperative complications requiring hospitalization were recorded in 9% of patients. The rate of pathological complete response was 41%. The rate of patients requiring conversion was 34%; however, 18% actually underwent conversion and the remaining 16% refused or were unfit. During the 14 months of median follow-up, local recurrence was detected in 7% of patients and all underwent salvage surgery. Of 19 patients in whom initially anterior resection was likely, 16% had abdominoperineal resection performed for a conversion or as a rescue procedure.

CONCLUSION

Our study suggests that the short-course radiation prior to local excision is a treatment option for high-risk patients.

Regression of rectal cancer with radiotherapy with or without concurrent capecitabine--optimising the timing of surgical resection

AIMS

To determine tumour regression (volume-halving time) obtained after chemo/radiotherapy, and thereby the ideal interval between the start of treatment and surgery in order to obtain a high rate of complete response.

MATERIALS AND METHODS

In total, 106 patients with cT3,4 rectal cancer who received preoperative radiotherapy alone or concurrently with capecitabine chemotherapy at Nottingham City Hospital, UK were studied. The rectal tumour volume visible on the computed tomography planning scan was compared with the residual pathological volume and the tumour volume-halving time calculated. The radiotherapy response was graded according to the Mandard system.

RESULTS

Fifty-three patients had radiotherapy alone, with 53 patients having concurrent chemoradiotherapy. The median tumour volume-halving time was found to be 14 days and not influenced by the addition of chemotherapy. The Mandard score, the interval from the start of treatment to surgery and the tumour volume-halving time were statistically associated with tumour regression. The median tumour volume in our series of 54 cm(3) would require an interval of 20 weeks after the start of treatment to surgery to regress to <0.1 cm(3) (10 volume-halving times; 140 days).

CONCLUSIONS

The initial tumour volume and median volume-halving time provide the best estimates for determining the optimum length of interval between the completion of preoperative chemo/radiotherapy and surgery in locally advanced rectal cancer.

Bowel dysfunction after treatment for rectal cancer

INTRODUCTION

Rectal cancer is a common disease in Western populations. Improved treatment modalities have resulted in increased survival and tumour control. With increasing survival there is a growing need for knowledge about the long-term side effects and functional results after the treatment.

AIM

To describe the long-term functional outcome in patients treated for rectal cancer through a systematic review of the current literature and to provide an outline of the promising developments within this area.

RESULTS

Standard resectional surgery with loss of the rectal reservoir function results in poor functional results in up to 50-60% of the patients. New methods of surgery including the construction of a neoreservoir and improvement of the technique for local excision have been developed to minimize the functional disturbances without compromising the oncological result. The addition of chemo and/or radiotherapy approximately doubles the risk of poor functional results. During the last decades the techniques for chemo/radiotherapy has been markedly improved with a positive impact on functional outcome. New methods for treatment of functional disturbances e.g. bowel irrigation and sacral nerve stimulation are currently under development.

PERSPECTIVES

To improve the functional outcome in this growing patient population several approaches can be taken. The primary cancer treatment must be improved by minimizing the surgical trauma and optimizing the imaging and radiation techniques. Population screening should be considered in order to find the cancers at an earlier stage, hereby increasing the proportion of patients eligible for local excision without the need for chemo/irradiation. All patients recovering from rectal resection should be examined and registered systematically regarding their functional results and treatment should be offered to the severely affected patients. More studies are still needed to evaluate the efficacy of irrigation and nerve stimulation in this patient group.

Accuracy of endorectal ultrasonography and computed tomography for restaging rectal cancer after preoperative chemoradiation

BACKGROUND

Preoperative restaging of irradiated rectal cancer is essential for the planning of optimal therapy. The aim of this study was to compare the accuracy of endorectal ultrasonography (ERUS) and CT in restaging rectal cancer after preoperative chemoradiation and to evaluate the factors affecting the accuracy of ERUS.

STUDY DESIGN

Eighty-three patients with initial, locally advanced rectal cancer were prospectively evaluated by ERUS (n=60) and CT (n=80) after preoperative chemoradiation and just before surgery. All patients then underwent subsequent surgical resection and complete pathologic staging.

RESULTS

In restaging the depth of invasion, the overall accuracy was 38.3% (23 of 60) by ERUS and 46.3% (37 of 80) by CT. Overstaging was more common than understaging with both imaging modalities. Accuracy for restaging lymph node metastasis was 72.6% (37 of 51) by ERUS and 70.4% (50 of 71) by CT. The predictive value of node-negative cases by ERUS was somewhat lower than that of CT (81.1% versus 85.4%, respectively). Complete pathology-proved remission was not correctly predicted in any of the 11 patients by any imaging modalities. Pathologic T and N staging correlated with the staging accuracy of ERUS (p=0.028 and p=0.001, respectively).

CONCLUSIONS

ERUS and CT may allow good prediction of node-negative rectal cancers, although they are inaccurate modalities for predicting treatment response on the rectal wall. New methods of interpretation and diagnostic criteria for ERUS and CT are essential for increasing the accuracy of cancer prediction in at-risk patients.

Prediction of rectal lymph node metastasis by pelvic computed tomography measurement

AIM

Rectal cancer staging represents a crucial step to select the best treatment for this tumour. Particularly after neo-adjuvant chemoradiotherapy (CRT), it may influence the surgical procedure (e.g. radical resection vs. local excision). The aim of this study was to determine the best lymph node size cut-off at computed tomography (CT) to predict nodal metastasis in rectal cancer patients with and without preoperative CRT.

METHODS

A consecutive series of patients operated on for primary mid-low rectal adenocarcinoma, all staged with pelvic CT scan, were subdivided as follows: those who underwent surgery alone treatment without CRT (Group A) and those who underwent preoperative CRT (Group B). All CT scans were re-viewed by a single radiologist and, based on the lymph node size, findings were compared with pathologic lymph node status (pN). At each lymph node size cut-off value, the following were calculated: accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). The best cut-off value was defined as having an accuracy >or=70% with the highest NPV.

RESULTS

The study population consisted of 162 patients: Group A (n=52) and Group B (n=110). Patients classified as pN-positive (n=45) had a higher number of and larger sized lymph nodes by CT scan than patients classified as pN-negative (n=117). The cut-off values with an accuracy >or=70% ranged between 7 and 11 mm in Group A and between 9 and 14 mm in Group B. The cut-off with the best NPV was 7 mm for Group A and 10mm for Group B.

CONCLUSIONS

Acknowledging the limitations of the dimensional criterion, lymph node size cut-off values found in our study may be useful for planning rectal cancer treatment using CT scan.

Long-term results of laparoscopic treatment for advanced rectal cancer

BACKGROUND

The management of advanced rectal cancer has changed into a multidisciplinary treatment model. Only limited randomized data are available for patients with rectal cancer treated laparoscopically.

AIM

We report a multimodal treatment of advanced rectal cancer: preoperative oncological treatment, use of endoscopic stent (for malignant obstruction), minimal invasive treatment.

METHODS

The Authors reported a series of 45 laparoscopic rectal resections for adenocarcinoma, some of them with malignant obstruction. Long-term oncological results were reviewed.

RESULTS

The 30-day mortality was 2.2%. Of 45 adenocarcinoma, 4 cases were obstructed. Successful stent positioning was obtained in all patients and treated with radiochemiotherapy before laparoscopic resection. The 5-year global survival rate (including stage IV) was 62.2%; for stage II was 77.9% and 53.8% for stage III.

CONCLUSION

This study indicates that laparoscopy for advanced rectal cancer have good long-term results. In high and middle rectal malignant obstructions, we considered the use of stents to be useful.

Local excision after radio(chemo)therapy for rectal cancer: is it safe?

According to current opinion, local excision in rectal cancer should be limited to selected T1N0 tumours. Preoperative radio(chemo)therapy provides an opportunity for expanding the use of local excision for more advanced tumours. The key rationale of this approach is the correlation between the radiosensitivity and inherited low aggressiveness of rectal cancer and the correlation between the radiosensitivity of the primary tumour and the radiosensitivity of mesorectal nodal disease. This allows for a selection of local excision for radiosensitive tumours or conversion to abdominal surgery in radioresistant cases. Eleven reports including a total of 311 patients treated with preoperative radio(chemo)therapy and local excision have been published. In some series, the tumours were initially large and unresectable by the transanal approach. Pathological data suggest that local excision must involve all tissue invaded on pre-treatment examination with a margin, even in patients with a clinical complete response. The pooled analysis has shown a local recurrence rate of 1% (1/83) for patients achieving a pathological complete response, 8% (3/40) for ypT1, 11% (4/37) for ypT2 and 3/9 for ypT3. In conclusion, the results of preoperative radio(chemo)therapy and local excision are encouraging and warrant a population-based, multicentre controlled study.

Usefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

AIM: To assess the usefulness of two independent histopathological classifications of rectal cancer regression following neo-adjuvant therapy.

METHODS: Forty patients at the initial stage cT3NxM0 submitted to preoperative radiotherapy (42 Gy during 18 d) and then to radical surgical treatment. The relationship between “T-downstaging” versus regressive changes expressed by tumor regression grade (TRG 1-5) and Nasierowska-Guttmejer classification (NG 1-3) was studied as well as the relationship between TRG and NG versus local tumor stage ypT and lymph nodes status, ypN.

RESULTS: Complete regression (ypT0, TRG 1) was found in one patient. “T-downstaging” was observed in 11 (27.5%) patients. There was a weak statistical significance of the relationship between “T-downstaging” and TRG staging and NG stage. Patients with ypT1 were diagnosed as TRG 2-3 while those with ypT3 as TRG5. No lymph node metastases were found in patients with TRG 1-2. None of the patients without lymph node metastases were diagnosed as TRG 5. Patients in the ypT1 stage were NG 1-2. No lymph node metastases were found in NG 1. There was a significant correlation between TRG and NG.

CONCLUSION: Histopathological classifications may be useful in the monitoring of the effects of hyperfractionated preoperative radiotherapy in patients with rectal cancer at the stage of cT3NxM0. There is no unequivocal relationship between “T-downstaging” and TRG and NG. There is some concordance in the assessment of lymph node status with ypT, TRG and NG. TRG and NG are of limited value for the risk assessment of the lymph node involvement.

Preoperative imaging staging of rectal cancer

Carcinomas of the rectum are associated with a significant local and distant recurrence rate. Not all patients are appropriate candidates for preoperative radiation therapy. Preoperative identification of those most likely to benefit from neoadjuvant therapy is important. There is no general consensus on the role of endorectal ultrasonography, computed tomography (CT), and magnetic resonance imaging (MRI) in staging patients with rectal cancer. Although the tumor stage is an important prognostic factor, preoperative assessment is associated with prediction of the circumferential resection margin. Newer developments such as coils, sequences and gradients in MRI, evolution of multidetector CT and new contrast media, allow for an algorithm selection aiming at the best diagnostic options for patients. The present review will discuss the current role of the various imaging modalities in staging carcinomas of the rectum.

Instrumental clinical restaging, pathological evaluation, and tumor regression grading: how to assess the response to neoadjuvant chemoradiotherapy for rectal cancer

INTRODUCTION

The object of neoadjuvant chemoradiotherapy regimens is a downstaging or downsizing of advanced rectal tumor to increase the rate of curative resection and reduce loco-regional failure. A reliable method of assessing response to adjuvant therapies is required to help standardize the assessments of new multimodality therapies. The purpose of this study was to evaluate the role played by tumor regression grading on the evaluation of pathological response to chemoradiotherapy, compared with both the predicting value of the clinical response to neoadjuvant therapy and pathologic response evaluation.

METHODS

From 1994 to 2003, 58 patients with a primary diagnosis of rectal cancer were studied at our department and enrolled in a single center, not randomized study based on 5-week sessions of radiotherapy associated with a 30-day 5-fluorouracil (FU) infusion, followed by surgical resection. Instrumental restaging and routine histological examination, including tumor regression grading, were performed to asses the response to neoadjuvant therapy.

RESULTS

The cCR rate corresponds to pCR rate, while a 3.5% of cPR and a 3.4% of cSD corresponded to a pPD. cPR and cSD show a PPV of 92.8% and 90.9% respectively, while cPD NPV is 20%. No case was found with no regression (grade 0). Tumor regression was defined grade 1 in 24.5% of cases, grade 2 was found in 58.5% of cases, 7.5% were grade 3, and 9.5% showed complete regression (grade 4). Pathologic response resulted to be associated with regression grade (p=0.006). Tumor regression grading is an independent variable for pT (p=0.0002), pN status (p=0.00004), pathologic staging (p=0.000001) and local recurrence (p=0.003).

CONCLUSION

Our results lead us to consider only pathologic evaluation to determine the response to neoadjuvant treatment: the application of tumor regression grading on the specimens obtained after combined neoadjuvant chemoradiotherapy and surgery is useful to plan a better therapeutic strategy on the ground of a quantitative evaluation of the response to neoadjuvant treatment; it shows it is an important comparable pathological feature, useful in comparing different protocols' results and differences between patient's response as well as prognostic factors.

The potential of restaging in the prediction of pathologic response after preoperative chemoradiotherapy for rectal cancer

BACKGROUND

We performed this study to prospectively evaluate the postchemoradiotherapy performance of transrectal ultrasonography (TRUS), pelvic computed tomography (CT) scan and magnetic resonance imaging (MRI), and endoscopic biopsies for predicting the pathologic complete response of rectal cancer patients.

METHODS

Four weeks after completion of preoperative chemoradiotherapy, 46 consecutive patients with mid to low rectal cancer were prospectively evaluated by proctoscopy, TRUS, and pelvic CT scan and MRI. On the basis of T and N status, patients were classified as T0 or T1-4 and N-negative or N-positive. For each staging modality used, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated. Findings were compared with the pathologic tumor-node-metastasis stage.

RESULTS

On histopathologic analysis, 12 patients had pT0 and 34 had pT1-4 lesions; out of 45 assessable patients, 9 were N-positive. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy in predicting T status (T0 vs. T >or=1) were 77%, 33%, 74%, 36%, and 64%, respectively, for TRUS; 100%, 0%, 74%, not assessable, and 74% for CT; and 100%, 0%, 77%, not assessable, and 77% for MRI. The corresponding figures in predicting N status (N-negative vs. N-positive) were, respectively, 37%, 67%, 21%, 81%, and 61% for TRUS; 78%, 58%, 32%, 91%, and 62% for CT; and 33%, 74%, 25%, 81%, and 65% for MRI.

CONCLUSIONS

Current rectal cancer staging modalities after chemoradiotherapy allow good prediction of node-negative cases, although none of them is able to predict the pathologic complete response on the rectal wall.

Gastrointestinal tract malignancies and positron emission tomography: an overview

(18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is highly accurate in restaging colorectal cancer, esophageal cancer, and gastrointestinal stromal tumors. Overall, it compares favorably with anatomical imaging in the evaluation of tumor recurrence because metabolic abnormalities usually precede a structural change. Initial staging of these malignancies with PET is best used in patients with locally advanced disease who may benefit from curative resection if distant metastases are not found. It also appears to have great potential in predicting histopathologic response to neoadjuvant therapy and in monitoring the success of radiofrequency ablation and (90)Y microspheres radioembolization soon after intervention. FDG-PET can be used in other gastrointestinal malignancies as a prognostic tool and to detect distant disease but its role has not yet been well defined.

Ten-year results of preoperative radiation followed by sphincter preservation for rectal cancer: increased local failure rate in nonresponders

BACKGROUND

The primary objective of this study was to determine the long-term outcome of sphincter preservation with preoperative radiation therapy (RT) and surgical resection in the treatment of distal rectal adenocarcinoma.

PATIENTS AND METHODS

Between April 1988 and December 1996, 36 (cT2, n=9; cT3, n=27) patients with rectal adenocarcinoma were enrolled on a phase I/II trial of preoperative RT followed by surgical resection. All patients had distal tumors that were clinically judged to require an abdominoperineal resection and received preoperative RT (50.4 Gy) followed by surgery. The median follow-up was 94.5 months (range, 4-187 months).

RESULTS

Of the 35 patients in this study who underwent resection, 77% were able to undergo sphincter preservation after preoperative RT. The pathologic complete response rate for these patients was 14%. The 10-year rates of overall survival and local failure for patients undergoing sphincter preservation were 54% and 21%, respectively. The 10-year local failure was 26% in patients with cT3 disease who underwent sphincter preservation. All local failures in this study occurred in patients with cT3 disease undergoing sphincter preservation; however, none of the patients with cT3 disease that was downstaged by preoperative RT experienced local failure. In contrast, 10-year local failure was 67% in the patients with cT3 disease that was not downstaged by RT. Sphincter function was good or excellent in 85% of patients at the time of last follow-up.

CONCLUSION

This approach provides excellent long-term results in all patients with cT2 disease and those with cT3 disease that is downstaged by RT. However, patients with cT3 disease that is not downstaged by RT have an increased risk of local failure. These data underscore the impact of tumor response to radiation on long-term oncologic outcome.

Modern management of rectal cancer: A 2006 update

The goal of this review is to outline some of the important surgical issues surrounding the management of patients with early (T1/T2 and N0), as well as locally advanced (T3/T4 and/or N1) rectal cancer. Surgery for rectal cancer continues to develop towards the ultimate goals of improved local control and overall survival, maintaining quality of life, and preserving sphincter, genitourinary, and sexual function. Information concerning the depth of tumor penetration through the rectal wall, lymph node involvement, and presence of distant metastatic disease is of crucial importance when planning a curative rectal cancer resection. Preoperative staging is used to determine the indication for neoadjuvant therapy as well as the indication for local excision versus radical cancer resection. Local excision is likely to be curative in most patients with a primary tumor which is limited to the submucosa (T1N0M0), without high-risk features and in the absence of metastatic disease. In appropriate patients, minimally invasive procedures, such as local excision, TEM, and laparoscopic resection allow for improved patient comfort, shorter hospital stays, and earlier return to preoperative activity level. Once the tumor invades the muscularis propria (T2), radical rectal resection in acceptable operative candidates is recommended. In patients with transmural and/or node positive disease (T3/T4 and/or N1) with no distant metastases, preoperative chemoradiation followed by radical resection according to the principles of TME has become widely accepted. During the planning and conduct of a radical operation for a locally advanced rectal cancer, a number of surgical management issues are considered, including: (1) total mesorectal excision (TME); (2) autonomic nerve preservation (ANP); (3) circumferential resection margin (CRM); (4) distal resection margin; (5) sphincter preservation and options for restoration of bowel continuity; (6) laparoscopic approaches; and (7) postoperative quality of life.

© 2006 The WJG Press. All rights reserved.

Complementary use of local excision and transanal endoscopic microsurgery for rectal cancer after neoadjuvant chemoradiation

BACKGROUND

Neoadjuvant therapies have significantly improved local control and survival of patients with rectal cancer. Nevertheless, although a complete pathologic response can be achieved in 30% of cases, a transabdominal surgical resection is always required. This study aimed, for the first time, to test in the literature the feasibility of local excision combined with transanal endoscopic microsurgery (TEM) as a surgical option for patients treated with neoadjuvant chemoradiation.

METHODS

Between July 1997 and December 2002, 30 patients with rectal cancer affected by an extraperitoneal tumor entered a protocol consisting of neoadjuvant chemoradiation followed by surgery. The surgical treatment, consisting of open surgery, local excision, or TEM, was planned according to the patient's clinical response after chemoradiation and distance from the anal verge.

RESULTS

A significant clinical downstaging was observed in eight patients. Five of these patients underwent TEM, and three had local excision. Consequently, open surgery was performed for 22 patients. Histology showed six cases of complete pathologic response: three in the open surgery group and three in the transanal excision group. After a mean follow-up period of 47 months, the disease-free survival rate was 77% in the open surgery group and 100% in TEM or local excision group.

CONCLUSIONS

The findings suggest the complementary feasibility of TEM and local excision after neoadjuvant chemoradiation. However, randomized trials are needed to confirm the oncologic safety of this approach.

Endoscopic ultrasound staging of rectal cancer: diagnostic value before and following chemoradiation

BACKGROUND

Endoscopic ultrasound (EUS) has been shown to be a reliable tool for staging rectal cancer. Nevertheless, the accuracy of EUS after chemoradiation remains unclear; therefore the purpose of the present paper was to compare the accuracy of EUS staging for rectal cancer before and following chemoradiation.

METHODS

Patients with rectal cancer undergoing EUS staging were stratified into two groups. Group I consisted of 66 patients who underwent surgery following EUS staging without preoperative chemoradiation. Group II consisted of 25 patients who had EUS evaluation following chemoradiation. The EUS staging was compared to surgical/pathological staging.

RESULTS

The accuracy of the T staging for group I was 86% (57/66). Inaccurate staging was mainly associated with overstaging EUS T2 tumors. The accuracy of the N staging for group I was 71% (47/66). The accuracy of EUS for a composite T and N staging relevant to treatment decisions in group I was 91%. In group II, the accuracy of T and N staging was 72% (18/25) and 80% (20/25), respectively. Overstaging EUS T3 tumors accounted for most inaccurate staging. The EUS staging predicted post-chemoradiation T0N0 stage correctly in only 50% of cases.

CONCLUSIONS

Preoperative staging of rectal cancer by EUS is a useful modality in determining the need for preoperative chemoradiation. The EUS T staging following chemoradiation appears to be less accurate. Detection of complete response may be insufficient for selecting patients for limited surgical intervention.

Prediction of mesorectal nodal metastases after chemoradiation for rectal cancer: results of a randomised trial: implication for subsequent local excision

BACKGROUND AND PURPOSE

For patients with rectal cancer treated with full thickness local excision the risk of mesorectal nodal metastases has to be very low. The aim was to assess this risk after preoperative radiotherapy in relation to pathological T-category.

PATIENTS AND METHODS

Three hundred sixteen patients with resectable cT3-4 low rectal carcinoma were randomised to receive either pre-operative 5 x 5 Gy irradiation with subsequent surgery performed within 7 days or chemoradiation (50.4, 1.8 Gy per fraction plus bolus 5-fluorouracil and leucovorin) followed by surgery after 4-6 weeks. The pathological reports of patients who fulfilled entry criteria and had preoperative irradiation followed by transabdominal surgery were analysed.

RESULTS

Significant downstaging of primary tumour (P<0.001) and of nodal disease (P=0.007) was observed after chemoradiation in comparison with short-course irradiation. In chemoradiation group, for patients with complete pathological response and for ypT1 category, the rate of nodal metastases was low - 5% (95% confidence interval [CI] 0-14%) and 8% (95% CI 0-24%), respectively. The rate of ypN-positive disease in chemoradiation group was similar to that recorded in short-course irradiation group for ypT2 category 26% (95% CI 14-38%) vs. 28% (95% CI 16-40%), P=0.83 and for ypT3-4 category 55% (95% CI 41-69%) vs. 64% (95% CI 54-74%), respectively, P=0.37. For ypT2 category after chemoradiation, the rate of nodal disease remained high even in subgroup with low residual cancer cells density (20%, 95% CI 4-36%).

CONCLUSIONS

For patients with tumours downstaged by chemoradiation to ypT0 and ypT1 full thickness local excision may be considered as an acceptable approach, because the risk of mesorectal lymph nodes metastases is low. The selection criteria for preoperative radio(chemo)therapy and local excision are discussed.

Clinical applications of endoscopic ultrasound to oncology

Endoscopic ultrasound (EUS) is a useful imaging modality in patients with certain gastrointestinal malignancies as well as lung cancer. In many cases, EUS has been shown to have superior staging accuracy compared with other imaging techniques such as computed tomography, magnetic resonance imaging and positron emission tomography. This article will review the role of EUS in diagnosing and staging esophageal, rectal, pancreatic and lung cancers as well as subepithelial lesions. Newer therapeutic applications of EUS, namely endoscopic mucosal resection for removal of localized lesions as well as celiac plexus neurolysis for pain control, will also be discussed.

Clinical examination following preoperative chemoradiation for rectal cancer is not a reliable surrogate end point

PURPOSE

Clinical assessment of rectal cancer response to preoperative combined-modality therapy (CMT) using digital rectal examination (DRE) has been proposed as a means of assessing efficacy of therapy. However, because the accuracy of this approach has not been established, we conducted a prospective analysis to determine the operating surgeon's ability to assess response using DRE.

PATIENTS AND METHODS

Ninety-four prospectively accrued patients with locally advanced rectal cancer (T3/4 or N1) were evaluated with DRE and sigmoidoscopy in order to determine the following tumor characteristics: size, location, mobility, morphology, and circumference. Following preoperative CMT (50.40 Gy with fluorouracil-based chemotherapy) and under general anesthesia, the same surgeon estimated tumor response based on changes in these tumor characteristics, assessed via DRE. Percent pathologic tumor response was determined prospectively by a single pathologist using whole mount sections of the resected cancer.

RESULTS

Clinical assessment using DRE underestimated pathologic response in 73 cases (78%). In addition, DRE was able to identify only 3 of 14 cases (21%) with a pathologic complete response. There were no clinical overestimates of response. None of the clinicopathologic tumor characteristics examined had a significant impact on DRE estimation of response.

CONCLUSION

Clinical examination underestimates the extent of rectal cancer response to preoperative CMT. Given the inaccuracy of DRE following preoperative CMT, it should not be used as a sole means of assessing efficacy of therapy nor for selecting patients following CMT for local surgical therapies.

Endorectal ultrasound in the preoperative evaluation of rectal cancer

For rectal cancer, the decisions about neoadjuvant therapy, radical resection, or local excision depend on accurate preoperative staging. Multiple modalities are available to stage rectal cancer, including digital rectal examination, computed tomography, magnetic resonance imaging (MRI), and endorectal ultrasound (ERUS). Digital rectal examination accuracy varies from 58% to 88% for depth of penetration. Computed tomography accuracy varies from 53% to 94% for depth of penetration and from 54% to 70% for lymph node metastases. Magnetic resonance imaging accuracy varies from 66% to 92% for depth of penetration and from 60% to 90% for lymph node metastases. Endorectal ultrasound varies from 62% to 92% for depth of penetration and from 64% to 88% for lymph node metastases. In all radiologic modalities, overstaging and understaging occurs. Endorectal ultrasound has the advantage of being portable and often office-based, requiring only minimal preparation and is well tolerated by the patient. Although MRI with the use of an endorectal coil may have a slightly higher accuracy for detecting lymph nodes, ERUS has been shown to be the most accurate method for the determination of the depth of wall penetration, and is comparable for lymph node metastases. Interpretation varies with operator experience. Three-dimensional (3D) ERUS may further improve staging accuracy. Endorectal ultrasound is an accurate method to preoperatively stage rectal cancers. Although operator-dependent, it can be readily performed at the time of patient evaluation with minimal preparation or patient discomfort. We are prospectively evaluating modifications to the current staging system and the use of 3D ERUS.

Accuracy of endoscopic ultrasound for restaging rectal cancer following neoadjuvant chemoradiation therapy

OBJECTIVES

Endoscopic ultrasound (EUS) provides important information in the initial staging of patients with rectal cancer. Preoperative combined modality chemotherapy and radiation (neoadjuvant therapy) for patients with locally advanced rectal cancer may reduce local recurrence and improve survival. The accuracy of EUS restaging of rectal cancer after chemoradiation has not been extensively studied and its usefulness is unclear. The aim of this study was to verify the accuracy of EUS in staging rectal cancer after neoadjuvant chemoradiation in a large cohort of patients.

METHODS

EUS staging was performed before and after concurrent 5-fluorouracil and hyperfractionated radiotherapy in 82 patients with recently diagnosed locally advanced rectal cancer. All patients underwent subsequent surgical resection and complete pathologic staging.

RESULTS

After chemoradiation, 16 patients (20%) had no residual disease at pathologic staging. (T0N0). However, EUS correctly predicted complete response to chemoradiation in only 10 of 16 patients (63%). Overall accuracy of EUS post chemoradiation for pathologic T-stage was only 48%. Fourteen percent were understaged and 38% overstaged. EUS accuracy for N-stage was 77%. The T-category was correctly staged before surgery in 23 of the 56 responders (41%) and in 16 of 24 nonresponders (67%). EUS was unable to accurately distinguish postradiation changes from residual tumor.

CONCLUSION

EUS staging of rectal cancer after chemoradiation is inaccurate, especially in the group of patients with visual and EUS evidence of response. Its routine use for staging purposes after neoadjuvant chemoradiation for rectal cancer should be discouraged.