Preoperative combined radiotherapy and chemotherapy for middle and lower rectal cancer: preliminary results

Accuracy of deep neural learning models in the imaging prediction of pathological complete response after neoadjuvant chemoradiotherapy for locally advanced rectal cancer: a systematic review

PURPOSE

Up to 15-27% of patients achieve pathologic complete response (pCR) following neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). Deep neural learning (DL) algorithms have been suggested to be a useful adjunct to allow accurate prediction of pCR and to identify patients who could potentially avoid surgery. This systematic review aims to interrogate the accuracy of DL algorithms at predicting pCR.

METHODS

Embase (PubMed, MEDLINE) databases and Google Scholar were searched to identify eligible English-language studies, with the search concluding in July 2022. Studies reporting on the accuracy of DL models in predicting pCR were selected for review and information pertaining to study characteristics and diagnostic measures was extracted from relevant studies. Risk of bias was evaluated using the Newcastle-Ottawa scale (NOS).

RESULTS

Our search yielded 85 potential publications. Nineteen full texts were reviewed, and a total of 12 articles were included in this systematic review. There were six retrospective and six prospective cohort studies. The most common DL algorithm used was the Convolutional Neural Network (CNN). Performance comparison was carried out via single modality comparison. The median performance for each best-performing algorithm was an AUC of 0.845 (range 0.71-0.99) and Accuracy of 0.85 (0.83-0.98).

CONCLUSIONS

There is a promising role for DL models in the prediction of pCR following neoadjuvant-CRT for LARC. Further studies are needed to provide a standardised comparison in order to allow for large-scale clinical application.

PROPERO REGISTRATION

PROSPERO 2021 CRD42021269904 Available from: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021269904 .

Multicentre randomized clinical trial of colonic J pouch or straight stapled colorectal reconstruction after low anterior resection for rectal cancer

BACKGROUND

Colonic J pouch reconstruction has been found to be associated with a lower incidence of anastomotic leakage than straight anastomosis. However, studies on this topic are underpowered and retrospective. This randomized trial evaluated whether the incidence of anastomotic leakage was reduced after colonic J pouch reconstruction compared with straight colorectal anastomosis following anterior resection for rectal cancer.

METHODS

This multicentre RCT included patients with rectal carcinoma who underwent low anterior resection followed by colorectal anastomosis. Patients were assigned randomly to receive a colonic J pouch or straight colorectal anastomosis. The main outcome measure was the occurrence of major anastomotic leakage. The incidence of global (major plus minor) anastomotic leakage and general complications were secondary outcomes. Risk factors for anastomotic leakage were identified by regression analysis.

RESULTS

Of 457 patients enrolled, 379 were evaluable (colonic J pouch arm 190, straight colorectal arm 189). The incidence of major and global anastomotic leakage, and general complications was 14·2, 19·5 and 34·2 per cent respectively in the colonic J pouch group, and 12·2, 19·0 and 27·0 per cent in the straight colorectal anastomosis group. No statistically significant differences were observed between the two arms. In multivariable logistic regression analysis, male sex (odds ratio 1·79, 95 per cent c.i. 1·02 to 3·15; P = 0·042) and high ASA fitness grade (odds ratio 2·06, 1·15 to 3·71; P = 0·015) were independently associated with the occurrence of anastomotic leakage.

CONCLUSION

Colonic J pouch reconstruction does not reduce the incidence of anastomotic leakage and postoperative complications compared with conventional straight colorectal anastomosis. Registration number NCT01110798 (http://www.clinicaltrials.gov).

Non-operative management of rectal cancer: understanding tumor biology

The management of locally-advanced rectal cancer involves a combination of chemotherapy, chemoradiation, and surgical resection to provide excellent local tumor control and overall survival. However, aspects of this multimodality approach are associated with significant morbidity and long-term sequelae. In addition, there is growing evidence that patients with a clinical complete response to chemotherapy and chemoradiation treatments may be safely offered initial non-operative management in a rigorous surveillance program. Weighed against the morbidity and significant sequelae of rectal resection, recognizing how to best optimize non-operative strategies without compromising oncologic outcomes is critical to our understanding and treatment of this disease.

Prediction of N0 Irradiated Rectal Cancer Comparing MRI Before and After Preoperative Chemoradiotherapy

BACKGROUND

The prediction of lymph node status using MRI has an impact on the management of rectal cancer, both before and after preoperative chemoradiotherapy.

OBJECTIVE

The purpose of this study was to maximize the negative predictive value and sensitivity of mesorectal lymph node imaging after chemoradiotherapy because postchemoradiation node-negative patients may be treated with rectum-sparing approaches.

DESIGN

This was a retrospective study.

SETTINGS

The study was conducted at a tertiary care hospital.

PATIENTS

Sixty-four patients with locally advanced rectal cancer who underwent preoperative chemoradiotherapy and MRI for staging and the assessment of response were evaluated.

MAIN OUTCOME MEASURES

The sums of the sizes of all mesorectal lymph nodes in each patient on both prechemoradiotherapy and postchemoradiotherapy imaging data sets were calculated to determine the lymph node global size reduction rates, taking these to be the outcomes of the histopathologic findings. Other included measures were interobserver agreement regarding the prediction of node status based on morphologic criteria and the diagnostic performance of contrast-enhanced images.

RESULTS

Using a cutoff value of a 70% lymph node global size reduction rate with only 15 node-positive patients on histopathology, the sensitivity in the prediction of nodal status and negative predictive value were 93% (95% CI, 70.2%-98.8%) and 97% (95% CI, 82.9%-99.8%) for observer 1 and 100% (95% CI, 79.6%-100%) and 100% (95% CI, 62.9%-100%) for observer 2. The areas under the receiver operating characteristic curves for the 2 observers were 0.90 (95% CI, 0.82-0.98; p < 0.0001) for observer 1 and 0.65 (95% CI, 0.50-0.79; p = 0.08) for observer 2. The efficacy of the morphologic criteria and contrast-enhanced images in predicting node status was limited after chemoradiotherapy.

LIMITATIONS

This study is limited by its small sample size and retrospective nature.

CONCLUSIONS

Assessing the lymph node global size reduction rate value reduces the risk of undetected nodal metastases and may be helpful in better identifying suitable candidates for the local excision of early stage rectal cancer. See Video Abstract at http://links.lww.com/DCR/A412.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Patterns and management of distant failure in locally advanced rectal cancer: a cohort study

PURPOSE

To determine the long-term outcomes of locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation (CRT) and surgery, and to analyze the management and survival once distant failure has developed.

METHODS

Data from LARC patients treated from 2000 to 2010 were retrospectively reviewed. CRT protocols were based on fluoropirimidines ± oxaliplatin. Follow-up consisted of physical examination, carcinoembryonic antigen levels, and chest-abdominal-pelvic CT scan.

RESULTS

The study included 228 patients with a mean age of 59 years. Forty-eight (21.1 %) patients had distant recurrence and 6 patients (2.6 %) had local recurrence. Median follow-up was 49 months. The 5- and 10-year actuarial disease free survival was 75.3 and 65.0 %, respectively. The 5- and 10-year actuarial overall survival (OS) was 89.6 and 71.2 %, respectively. Patients were classified as having liver (14 patients) or lung (27 patients) relapse according to the organ firstly metastasized. The variables significantly associated by univariate Cox analysis to survival were the achievement of an R0 metastases resection and the Köhne risk index, while the metastatic site showed a statistical trend. By multivariate Cox analysis, the only variable associated with survival was a R0 resection (HR = 16.3, p < 0.001). Median OS for patients undergoing a R0 resection was 73 months (95 % CI 67.8-78.2) compared to 25 months (95 % CI 5.47-44.5) in those non-operated patients (p < 0.001).

CONCLUSIONS

Combined treatment for LARC obtains a 5-year OS rounding 90 %. Follow-up based on thoracic-abdominal CT scan allows an early diagnosis of metastatic lesions. Surgical resection of metastases, regardless of their location, greatly increases the patient's survival rate.

Prognosis factors for recurrence in patients with locally advanced rectal cancer preoperatively treated with chemoradiotherapy and adjuvant chemotherapy

BACKGROUND

Neoadjuvant chemoradiotherapy followed by total mesorectal excision has improved the outcome of locally advanced rectal carcinoma.

OBJECTIVE

The aim of this study was to identify independent prognosis factors of disease recurrence in a group of patients treated with this approach.

DESIGN AND PATIENTS

This study was retrospective in design. Data from patients with locally advanced rectal cancer who had completed treatment from 2000 to 2010 were reviewed.

SETTINGS

The analysis was performed in a tertiary referral center.

MAIN OUTCOME MEASURES

The primary outcomes measured were the recurrence risk factors.

RESULTS

The cohort consisted of 228 patients; 69.3% of them were men, and median age was 59 years. Stage III rectal cancer was found in 64.9% of patients. The most frequently administered therapy was concurrent capecitabine, oxaliplatin, and 7-field radiotherapy, followed by 3-field radiotherapy and fluoropyrimidines. After a median follow-up of 49 months, 23.7% of the patients experienced disease recurrence: 2.6% had local recurrence, 21.1% had distant metastases, and 0.5% had both. Factors significantly correlated with recurrence risk in multivariate logistic regression were y-pathological stage (III vs I/II: OR = 2.51), tumor regression grade (1/2 vs 3+/4: OR = 3.34; 3 vs 3+/4: OR = 1.20), and low rectal location (OR = 2.36). The only independent prognosis factor for liver metastases was tumor regression grade (1/2 vs 3+/4: OR = 4.67; 3 vs 3+/4: OR = 1.41), whereas tumor regression grade (1-2 vs 3+/4: OR = 5.5; 3 vs 3+/4: OR = 1.84), low rectal location (OR = 3.23), and previous liver metastasis (OR = 7.73) predicted lung recurrence.

LIMITATIONS

This is a single institutional experience, neoadjuvant combined therapy is not homogeneous, and the analysis has been performed in a retrospective manner.

CONCLUSIONS

Patients with low third locally advanced rectal cancer with a poor response to neoadjuvant chemoradiotherapy (high y-pathological stage or low tumor regression grade) are at high risk of recurrence. Intense surveillance and the design of alternative therapeutic approaches aimed to lower the distant failure rate seem warranted.

Gene polymorphisms predict toxicity to neoadjuvant therapy in patients with rectal cancer

BACKGROUND

Toxicity from neoadjuvant chemoradiation therapy (NT) increases morbidity and limits therapeutic efficacy in patients with rectal cancer. The objective of this study was to determine whether specific polymorphisms in genes associated with rectal cancer response to NT were correlated with NT-related toxicity.

METHODS

One hundred thirty-two patients with locally advanced rectal cancer received NT followed by surgery. All patients received 5-fluorouracil (5-FU) and radiation (RT), and 80 patients also received modified infusional 5-FU, folinic acid, and oxaliplatin chemotherapy (mFOLFOX-6). Grade ≥3 adverse events (AEs) that occurred during 5-FU/RT and during combined 5-FU/RT + mFOLFOX-6 were recorded. Pretreatment biopsy specimens and normal rectal tissues were collected from all patients. DNA was extracted and screened for 22 polymorphisms in 17 genes that have been associated with response to NT. Polymorphisms were correlated with treatment-related grade ≥3 AEs.

RESULTS

Overall, 27 of 132 patients (20%) had grade ≥3 AEs; 18 patients had a complication associated only with 5-FU/RT, 3 patients experienced toxicity only during mFOLFOX-6, and 6 patients had grade ≥3 AEs associated with both treatments before surgery. Polymorphisms in the genes x-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1), xeroderma pigmentosum group D (XPD), and tumor protein 53 (TP53) were associated with grade ≥3 AEs during NT (P < .05). Specifically, 2 polymorphisms-an arginine-to-glutamine substitution at codon 399 (Q399R) in XRCC1 and a lysine-to-glutamine substitution at codon 751 (K751Q) in XPD-were associated with increased toxicity to 5-FU/RT (P < .05), and an arginine-to-proline substitution at codon 72 (R72P) in TP53 was associated with increased toxicity to mFOLFOX-6 (P = .008).

CONCLUSIONS

Specific polymorphisms in XRCC1, XPD, and TP53 were associated with increased toxicity to NT in patients with rectal cancer. The current results indicated that polymorphism screening may help tailor treatment for patients by selecting therapies with the lowest risk of toxicity, thus increasing patient compliance.

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.

Postoperative complications following surgery for rectal cancer

OBJECTIVE

This systematic review was designed to determine postoperative complication rates of radical surgery for rectal cancer (abdominal perineal resection and anterior resection).

SUMMARY OF BACKGROUND DATA

Lack of accepted complication rates for rectal cancer surgery may hinder quality improvement efforts and may impede the conception of future studies because of uncertainty regarding the expected event rates.

METHODS

All prospective studies of rectal cancer receiving radical surgery published between 1990 and August 2008 were obtained by searching Ovid MEDLINE, EMBASE, as well as ASCO GI, CAGS, and ASCRS meeting abstracts between 2004 and 2008. There was no language restriction. The outcomes extracted were anastomotic leak, pelvic sepsis, postoperative death, wound infection, and fecal incontinence. Summary complication rates were obtained using a random effects model; the Z-test was used to test for study heterogeneity.

RESULTS

Fifty-three prospective cohort studies and 45 randomized controlled studies with 36,315 patients (24,845 patients had an anastomosis) were eligible for inclusion. Most of the studies found were based in continental Europe (58%), followed by Asia (25%), United Kingdom (10%), North America (5%), and Australia/New Zealand. The anastomotic leak rate, reported in 84 studies, was 11% (95% CI: 10, 12); the pelvic sepsis rate, in 29 studies, was 12% (9, 16); the postoperative death rate, in 75 studies, was 2% (2, 3); and the wound infection rate, in 50 studies, was 7% (5, 8). Fecal incontinence rates were reported in too few studies and so heterogeneously that numerical summarization was inappropriate. Year of publication, use of preoperative radiation, use of laparoscopy, and use of protecting stoma were not significant variables, but average age, median tumor height, and method of detection (clinical vs. radiologic) showed significance to explain heterogeneity in anastomotic leak rates. Year of publication, study origin, average age, and use of laparoscopy were significant, but median tumor height and preoperative radiation use were not significant in explaining heterogeneity among observed postoperative death rates. With multivariable analysis, only average age for anastomotic leak and year of publication for postoperative death remained significant.

CONCLUSIONS

Benchmark complication rates for radical rectal cancer surgery were obtained for use in sample size calculations in future studies and for quality control purposes. Postoperative death rates showed improvement in recent years.

Prospective assessment of imaging after preoperative chemoradiotherapy for rectal cancer

BACKGROUND

The aim of the study was to assess the accuracy of imaging techniques in predicting pathologic tumor (ypT), node (ypN) stages and the circumferential resection margin (ypCRM) status of rectal cancers after preoperative chemoradiotherapy (CRT).

METHODS

Using pelvic computed tomography (CT), magnetic resonance imaging (MRI), and endorectal ultrasound (ERUS), 90 consecutive patients with locally advanced mid-to-low rectal cancer were prospectively assessed. Postirradiation T and N stages and infiltration of the CRM, as assessed by CT, MRI and ERUS, were compared with histopathologic findings.

RESULTS

The accuracy of ypT staging was low, whatever the imaging technique used (37% by CT, 34% by MRI, and 27% by ERUS), the most frequent inaccuracy being overstaging. Imaging showed a good specificity and good negative predictive values (NPV) when mural staging was grouped into ypT ≤ 3 and ypT4 categories; in particular, ERUS achieved a 92% specificity and 95% NPV. CRM involvement was correctly predicted in 71% of patients by CT (74% specificity; 93% NPV) and in 85% by MRI (88% specificity; 95% NPV). The accuracy for nodal staging was 62%, 68%, and 65% by CT, MRI and ERUS, respectively; the corresponding NPV were 88%, 78%, and 76%.

CONCLUSION

Current imaging techniques are inaccurate in restaging rectal cancer after CRT but are useful in predicting T ≤ 3 tumors, cases with negative nodes and tumor-free CRM. These findings may be of clinical relevance for planning less invasive surgery.

Tumor response is predicted by patient genetic profile in rectal cancer patients treated with neo-adjuvant chemo-radiotherapy

The aim of the study was the identification of a pharmacogenetic profile predictive of the tumor regression grade (TRG), considered as tumor response parameter, after neo-adjuvant treatment in rectal cancer patients. A total of 238 rectal cancer patients treated in a neo-adjuvant setting by a fluoropyrimidines-based chemo-radiotherapy (RT) were genotyped for 25 genetic polymorphisms in 16 genes relevant for treatment-associated pathways. Two polymorphisms were associated with TRG in a multivariate analysis: hOGG1-1245C > G, which can affect radiosensitivity and MTHFR-677C > T, which is involved in fluoropyrimidines action. Patients bearing at least one variant allele had a lower chance to get TRG ≤ 2 (OR = 0.46 95% CI 0.23-0.90, P = 0.024; and OR = 0.48 95% CI 0.24-0.96, P = 0.034; respectively). An association trend was observed for ABCB1-3435C > T, which is responsible for the multi-drug resistance (odds ratio (OR) = 1.96, 95% confidence interval (CI) 0.98-3.95, P = 0.057). Exploratory classification and regression tree (CART) analysis highlighted high-order gene-gene and gene-environment interactions and a genetic signature associated with differential response, with hOGG1-1245C > G as the most predictive factor. Other significant variables were: ABCB1-3435C > T, MTHFR-677C > T, ERCC1-8092C > A, ABCC2-1249G > A, XRCC1-28152G > A, XRCC3-4541A > G and patients gender. On the basis of CART results, patients were categorized into three groups according to tumor response probability: intermediate and high profiles had a higher probability to get TRG ≤ 2 as compared with low profiles (OR = 4.12 95% CI 1.46-11.65, P < 0.001 and OR = 12.44, 95% CI 5.52-28.04, P < 0.0001, respectively). This study evidences a major role of hOGG1-1245C > G and MTHFR-677C > T polymorphisms in the tumor response of rectal cancer patients treated with chemo-RT in neo-adjuvant setting, and shows the relevance of gene-gene and gene-environment interactions for complex phenotypes as tumor response.

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.

Gene expression profiles of epidermal growth factor receptor, vascular endothelial growth factor and hypoxia-inducible factor-1 with special reference to local responsiveness to neoadjuvant chemoradiotherapy and disease recurrence after rectal cancer surgery

AIMS

To establish a causal relationship between the gene expression profiles of angiogenetic molecular markers, including epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1 (HIF-1), in rectal cancer and the local responsiveness to neoadjuvant chemoradiotherapy and subsequent disease recurrence.

MATERIALS AND METHODS

We examined the pre-treatment tumour biopsies (n=40) obtained from patients with rectal adenocarcinoma (clinical International Union Against Cancer stage ll/III) who were scheduled to receive neoadjuvant 5-fluorouracil-based chemoradiotherapy for EGFR, VEGF and HIF-1 expression by quantitative real-time polymerase chain reaction.

RESULTS

Responders (patients with significant tumour regression, i.e. pathological grades 2/3) showed significantly lower VEGF, HIF-1 and EGFR gene expression levels than the non-responders (patients with insignificant tumour regression, i.e. pathological grades 0/1) in the pre-treatment tumour biopsies. The elevated expression level of each gene could predict patients with a low response to chemoradiation. During the median follow-up of all patients (41 months; 95% confidence interval 28-60 months), 6/40 (15%) developed disease recurrence. Although local responsiveness to neoadjuvant chemoradiotherapy was associated with neither local nor systemic disease recurrence, lymph node metastasis and an elevated VEGF gene expression level were independent predictors of systemic disease recurrence. The 3-year disease-free survival rates of the patients with lower VEGF or EGFR expression levels were significantly lower than those of patients with higher VEGF or EGFR expression levels.

CONCLUSIONS

Analysing VEGF expression levels in rectal cancer may be of benefit in estimating the effects of neoadjuvant chemoradiotherapy and in predicting systemic recurrence after rectal cancer surgery.

An interval >7 weeks between neoadjuvant therapy and surgery improves pathologic complete response and disease-free survival in patients with locally advanced rectal cancer

BACKGROUND

We assessed whether the time interval between neoadjuvant therapy and surgery affects the operative and postoperative morbidity and mortality, the pathologic complete response (pCR) rate, and disease recurrence in locally advanced rectal cancer.

METHODS

One-hundred and thirty-two patients with locally advanced low- and mid-rectal cancer underwent neoadjuvant chemoradiation followed by radical resection (October 2000 to December 2006). Data on the neoadjuvant regime, neoadjuvant-surgery interval, final pathology, type of operation, operative time, intraoperative blood transfusions, postoperative complications, length of hospital stay, disease recurrence, and mortality were reviewed. The patients were divided into two groups according to the neoadjuvant-surgery interval: </=7 weeks (group A, n = 48), and >7 weeks (group B, n = 84).

RESULTS

The groups were demographically comparable except for the group A patients being younger at operation. The median interval between chemoradiation and surgery was 56 days (range 13-173 days). Thirty-seven patients (28%) had a pCR and near pCR. Fifty three patients (40%) had complications. There was no in-hospital mortality. Surgery type, operative time, number of intraoperative blood transfusions, postoperative complications, and length of hospitalization were not influenced by the interval length. The pCR and near pCR rates were higher with longer interval: 17% in group A, 35% in group B (P = 0.03). Patients operated at an interval >7 weeks had significantly better disease-free survival (P = 0.05).

CONCLUSIONS

A neoadjuvant-surgery interval >7 weeks was associated with higher rates of pCR and near pCR, decreased recurrence and improved disease-free survival.

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.

Rectal cancer treatment: Improving the picture

Multidisciplinary approach for rectal cancer treatment is currently well defined. Nevertheless, new and promising advances are enriching the portrait. Since the US NIH Consensus in the early 90’s some new characters have been added. A bird’s-eye view along the last decade shows the main milestones in the development of rectal cancer treatment protocols. New drugs, in combination with radiotherapy are being tested to increase response and tumor control outcomes. However, therapeutic intensity is often associated with toxicity. Thus, innovative strategies are needed to create a better-balanced therapeutic ratio. Molecular targeted therapies and improved technology for delivering radiotherapy respond to the need for accuracy and precision in rectal cancer treatment.

Oncologic outcomes after neoadjuvant chemoradiation followed by curative resection with tumor-specific mesorectal excision for fixed locally advanced rectal cancer: Impact of postirradiated pathologic downstaging on local recurrence and survival

OBJECTIVE

The purpose of this study was to determine the oncologic outcomes and clinical factors affecting survival in patients who underwent neoadjuvant chemoradiotherapy following tumor specific mesorectal excision for locally advanced, fixed rectal cancer.

SUMMARY BACKGROUND DATA

Neoadjuvant chemoradiation therapy has resulted in significant tumor downstaging, which enhances curative resection and subsequently improves local disease control for rectal cancer. However, oncologic outcomes, according to clinical factors, have not yet been fully understood in locally advanced and fixed rectal cancer.

METHODS

A total of 114 patients who had undergone neoadjuvant chemoradiation for advanced rectal cancer (T3 or T4 and node positive) were investigated retrospectively. Chemotherapy was administered intravenously with 5-FU and leucovorin during weeks 1 and 5 of radiotherapy. The total radiation dose was 5040 cGY in 25 fractions delivered over 5 weeks. Tumor-specific mesorectal excision was done 4 to 6 weeks after the completion of neoadjuvant chemoradiation. Survival and recurrence rates, according to the pathologic stage, were evaluated. Moreover, factors affecting survival were investigated.

RESULTS

The 5-year survival rates according to pathologic stage were: 100% in pathologic complete remission (n = 10), 80% in stage I (n = 23), 56.8% in stage II (n = 34), and 42.3% in stage III (n = 47) (P = 0.0000). Local, systemic, and combined recurrence rates were 11.4%, 22.8%, and 3.5%, respectively. Multivariate analysis showed that the pathologic N stage and operation method were the independent factors affecting survival rate.

CONCLUSION

Pathologic complete remission showed excellent oncologic outcomes, and the pathologic N stage was the most important factor for oncologic outcomes.

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.

A haplotype of the methylenetetrahydrofolate reductase gene predicts poor tumor response in rectal cancer patients receiving preoperative chemoradiation

OBJECTIVE

The objective of the present study was to evaluate whether germline methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms as well as polymorphisms in the thymidylate synthase gene promoter, namely the variable number tandem repeat polymorphism (TS VNTR) and the intrarepeat G to C single nucleotide polymorphism (TS SNP), are predictive markers of tumor regression in rectal cancer patients following preoperative chemoradiotherapy.

BASIC METHODS

Blood samples from 125 patients with primary adenocarcinoma of the mid-low rectum who received 5-fluorouracil-based chemotherapy and external beam radiotherapy (median dose 48.4 Gy), 125 patients (women n=45, men n=80; median age 60 years, range 31-79 years) were genotyped. Response to preoperative treatment was evaluated employing the Tumor Regression Grade criteria. On the basis of the pathologic response, patients were classified as responders (TRG 1-2, n=48) and non-responders (TRG 3-5, n=74). Three patients were excluded because of insufficient data.

MAIN RESULTS

Among the polymorphic variants examined, the MTHFR 677T-1298A haplotype was, upon univariate analysis, the only variable found associated with tumor regression (P=0.004). Moreover, at multivariate analysis, the MTHFR 677T-1298A haplotype was an independent predictor of tumor regression. Patients not carrying the MTHFR 677T-1298A haplotype (odds ratio 0.29, 95% confidence interval 0.13-0.64, P=0.002) displayed a higher response rate than patients with the MTHFR 677T-1298A haplotype.

CONCLUSIONS

Unlike TS VNTR and SNP polymorphisms, MTHFR 677T-1298A haplotype in genomic DNA has the potential to be a predictive marker of tumor response in rectal cancer patients submitted to preoperative chemoradiotherapy.

Preoperative versus postoperative treatment for locally advanced rectal carcinoma

EPIDEMIOLOGY

Overall mortality of rectal cancer at 5 years is approximately 40%. This cancer is commonly diagnosed at an early stage, but because of local relapse and/or metastatic disease, only half of radically resected patients can be considered disease free.

COMMON TREATMENT

The value of adding radiotherapy to surgery in the treatment of patients with resectable rectal cancer has been assessed in trials using either preoperative or postoperative irradiation.

IMPROVEMENTS IN TREATMENT

Preoperative radiotherapy and complete resection are established modalities for Stage II and III rectal cancer whilst data reporting improvement of survival by preoperative chemoradiotherapy are still not available. At present, the improved results reported by Phase II trials in terms of local control, sphincter saving and tumor regression grade make neoadjuvant treatment the 'standard' therapy only in North America and some other countries, but the concept of preoperative combined modality treatment is not supported globally.

Pre-operative combined modality therapy in the management of locally advanced rectal cancer

AIMS

To review the use of pre-operative combined modality therapy (CMT, chemotherapy with radiotherapy) in the management of resectable rectal cancer.

METHODS

A systematic search was performed on pre-operative CMT and rectal cancer. Additional information was retrieved from hand searching the literature and from relevant congress proceedings. We addressed the following issues: Phase II studies of pre-operative CMT, pre-operative radiotherapy (RT) alone vs pre-operative CMT, pre-operative vs post-operative CMT, functional outcome and pathologic downstaging after CMT, prediction and importance of complete response to CMT.

RESULTS

Pre-operative CMT results in an average pathological complete response (pCR) rate of 18.5% in Phase II studies. Compared with pre-operative RT alone, the addition of CT significantly improves tumour response but not overall survival while acute toxicity increases and the effect on sphincter preservation is at present unclear. Pre-operative CMT has been proven to be superior to post-operative CMT in a German multicenter randomized trial. The scarce available data suggest that the addition of CT might worsen anorectal function compared to pre-operative RT alone. Although a significant pathological response is prognostically favourable, the clinical and imaging tools available at present do not allow to accurately predict pCR in clinical complete responders confirming the indication for surgery in this subgroup.

CONCLUSIONS

Pre-operative CMT enhances tumour response and could therefore, have a role in patients with possibly invaded resection margins or low lying cancers, although both acute toxicity and anorectal function are worse compared to RT alone. The final results of ongoing randomized trials will more accurately establish the role of pre-operative CMT in resectable rectal cancer patients.

Can Rectal Cancers With Pathologic T0 After Neoadjuvant Chemoradiation (ypT0) Be Treated by Transanal Excision Alone?

BACKGROUND

Patients with rectal cancer who have complete rectal wall tumor regression after neoadjuvant chemoradiation probably have eradication of tumor cells in the mesorectum as well, thus raising the possibility of transanal excision.

METHODS

All pathology reports of all patients with locally advanced low and mid rectal cancer who underwent preoperative chemoradiation followed by radical resection from May 2000 to June 2004 were reviewed to evaluate the correlation between complete tumor response (ypT0) and nodal response.

RESULTS

One hundred one consecutive patients had neoadjuvant chemoradiation followed by definitive operation. Four were excluded, leaving 64 men and 33 women (median age, 62 years). Fifty-three patients (55%) had mid rectal cancer, and 44 (45%) had low rectal cancer. Fifty-eight patients (60%) underwent low anterior resection, and 36 (37%) underwent abdominoperineal resection. In 17 patients (18%), no residual tumor cells were present within the rectal wall. One patient (6%) with ypT0 disease had positive lymph nodes.

CONCLUSIONS

No residual tumor in the rectal wall correlates with the absence of viable cancer cells in the mesorectal tissue (94%). Approximately 10% of T1 tumors have involved lymph nodes, and local excision is an accepted option. Transanal excision could probably be considered in a highly selected group of patients with a mural pathologic complete response to neoadjuvant therapy. This approach should be prospectively investigated, and strict selection guidelines should be used.

Outcome after curative resection for locally recurrent rectal cancer

PURPOSE

Few biologic markers have been studied as prognostic factors in recurrent rectal carcinoma patients. We sought to determine the influence of clinical, pathologic, and biologic (p53, bcl-2, and ki-67) variables on survival after curative resection of locally recurrent rectal cancer.

METHODS

Retrospective review of patients with locally recurrent rectal cancer who received surgery with curative intent.

RESULTS

From 1988 to 1998, 134 patients with locally recurrent rectal cancer underwent operative exploration. Curative resection was performed in 85 patients. Median follow-up was 43 (range, 1.3-149) months. On multivariate analysis, negative predictors of overall survival included an elevated carcinoembryonic antigen level (P=0.02; hazard ratio 2.41; 95 percent confidence interval, 1.19-4.89) and an R1 resection margin (P = 0.01; hazard ratio, 2.81; 95 percent confidence interval, 1.27-6.21). In 26 patients for whom biologic variables were available, p53, bcl-2, and ki-67 did not significantly impact disease-specific survival or overall survival. Five-year disease-specific survival, overall survival, and pelvic control rates were 46, 36, and 51 percent respectively. Of the 50 patients who relapsed, time to second local recurrence was longer than time to development of metastasis (median, 16.5 vs. 9 months). Median survival for patients with metastatic recurrence was 26.l vs. 41.5 months for those with a subsequent local recurrence alone.

CONCLUSIONS

Approximately two-thirds of patients with locally recurrent rectal cancer can be resected for cure. Preoperative carcinoembryonic antigen and an R0 resection margin were the only significant predictors of overall survival. p53, bcl-2, and ki-67 did not impact survival outcomes.

Incidence and clinical impact of sterilized disease and minimal residual disease after preoperative radiochemotherapy for rectal cancer

PURPOSE

In advanced rectal cancer, chemoradiation can induce downstaging until complete disappearance of the tumor or its persistence in minimal form. The complete sterilized and the minimal residual disease often are considered similar. We evaluated the specific incidence of these two conditions and analyzed their impact in terms of local recurrence, distant metastasis, and survival.

METHODS

We studied 139 uT3/T4 N0/N+ rectal cancers, treated with preoperative chemoradiation and curative surgery after six to eight weeks. We evaluated ypTNM stage and tumoral regression, according to the five degrees proposed by Dworak, with special attention to 4 and 3 (sterilized and minimal residual disease).

RESULTS

Tumor downstaging occurred in 65 patients (46.7 percent), including 25 sterilized lesions (17.9 percent) and 24 minimal residual disease (17.2 percent). In median follow-up of 30 months, none of the patients with sterilized disease developed local or distant recurrence. Among patients with minimal residual disease, none developed local recurrence, whereas two (8.3 percent) developed distant metastasis, and one died from disease. In patients with gross residual disease (Grade 2, 1, 0) the percentage of local recurrence was 8.8 percent, distant recurrence 26.6 percent, and 13.3 percent died from disease. The difference between three groups is statistically significant as regards local and distant recurrence.

CONCLUSIONS

After preoperative therapy, the sterilized disease shows an excellent prognosis. The minimal residual disease has an important numeric incidence. Its outcome is different, with a not-negligible risk of distant recurrence. The minimal residual disease has a much better prognosis in comparison with the gross residual disease.

Preoperative chemotherapy and radiotherapy for locally advanced rectal cancer

BACKGROUND

The adjuvant treatment of rectal cancer is a rapidly evolving field. The standard approach is a combination of chemotherapy and radiotherapy, with the optimal treatment combination and sequencing yet to be determined. Here, we report our early experience of preoperative chemotherapy and radiotherapy (CRT) in locally advanced rectal cancer at Radiation Oncology Victoria to determine its efficacy and the rate of sphincter preservation.

METHODS

Sixty-nine patients (46 men and 23 women) with locally advanced rectal cancer (T3-4 or N1) were treated with preoperative CRT followed by surgical resection of disease. Chemotherapy consisted of either bolus or continuous venous infusion of 5-fluorouracil (5-FU). Radiotherapy to a dose of 45 Gy was delivered to the pelvis followed by a boost of 5.4-14.4 Gy in the majority of patients. Surgical resection was carried out 4-8 weeks following completion of preoperative CRT. Univariate and multivariate analyses were performed to examine variables that may influence local recurrence and overall survival rates.

RESULTS

All patients underwent a complete macroscopic resection, including the three patients that had unrecognized distant metastases discovered at the time of operation. Only two patients had microscopic residual disease. Sphincter preservation was achieved in 16 of 25 patients who were thought to require an abdominoperineal resection. Tumour and/or nodal downstaging were achieved in 47 patients (68%), with a pathological complete response in 12 (17%). At a median follow up of 29 months post-surgery, five patients (7.2%) have developed a local recurrence. Overall 21 patients (30%) have progressed and 12 (18%) have died. Treatment-related toxicity was acceptable and there was no treatment-related mortality. There was no significant relationship found between the pathological response to treatment and any clinical endpoint.

CONCLUSIONS

Our results confirm the high response rates and acceptable toxicity of preoperative treatment. Further studies are required to better define the impact of preoperative chemotherapy and radiotherapy on long-term outcomes.

A phase I-II study of weekly oxaliplatin, 5-fluorouracil continuous infusion and preoperative radiotherapy in locally advanced rectal cancer

BACKGROUND

Oxaliplatin (OXA) significantly enhanced the antitumour activity of 5-fluorouracil (FUra) in patients with advanced colorectal cancer and displayed radiosensitising properties in preclinical studies. This study was thus performed to test the feasibility, identify the recommended doses (RDs) and explore preliminarily the clinical activity of weekly OXA and infused FUra combined with preoperative pelvic radiotherapy.

PATIENTS AND METHODS

Forty-six patients with recurrent or locally advanced (cT3-4 and/or N+) adenocarcinomas of the mid-low rectum were treated with escalating doses of OXA (25, 35, 45, 60 mg/m2, weekly for 6 weeks) and FUra (200-225 mg/m2/day, 6-week infusion) concurrent to preoperative pelvic radiotherapy (50.4 Gy/28 fractions). The RDs for the phase II part of the study were immediately below the level resulting in dose-limiting toxicities in more than one third of the patients, or corresponded to the last planned dose level.

RESULTS

In the escalation phase, dose-limiting toxicities only occurred in one patient at the fourth level and one of six patients treated at the last planned dose level (grade III diarrhoea). OXA 60 mg/m2 and FUra 225 mg/m2/day are therefore the RDs for the regimen. Among 25 patients globally treated at these doses (phase II part), the incidence of grade III diarrhoea was 16% with no grade IV toxicity. Neurotoxicity did not exceed grade II (12%). All patients completed radiotherapy and were operated on as scheduled. Twenty-one of 25 patients had the tumour down-staged after chemoradiation with seven (28%) pathological complete responses and 12 (48%) residual tumours limited to ypT1-2N0.

CONCLUSIONS

Weekly OXA, at doses potentially active systemically, can be combined with full-dose, infused FUra and radiotherapy. Given the low toxicity and promising activity, this regimen is being compared to standard FUra-based pelvic chemoradiation in a randomised study.

Long-term oncologic outcome following preoperative combined modality therapy and total mesorectal excision of locally advanced rectal cancer

OBJECTIVE

Our aims were to (1) determine the long-term oncologic outcome for patients with rectal cancer treated with preoperative combined modality therapy (CMT) followed by total mesorectal excision (TME), (2) identify factors predictive of oncologic outcome, and (3) determine the oncologic significance of the extent of pathologic tumor response.

SUMMARY BACKGROUND DATA

Locally advanced (T3-4 and/or N1) rectal adenocarcinoma is commonly treated with preoperative CMT and TME. However, the long-term oncologic results of this approach and factors predictive of a durable outcome remain largely unknown.

METHODS

Two hundred ninety-seven consecutive patients with locally advanced rectal adenocarcinoma at a median distance of 6 cm from the anal verge (range 0-15 cm) were treated with preoperative CMT (radiation: 5040 centi-Gray (cGy) and 5-fluorouracil (5-FU)-based chemotherapy) followed by TME from 1988 to 2002. A prospectively collected database was queried for long-term oncologic outcome and predictive clinicopathologic factors.

RESULTS

With a median follow-up of 44 months, the estimated 10-year overall survival (OS) was 58% and 10 year recurrence-free survival (RFS) was 62%. On multivariate analysis, pathologic response >95%, lymphovascular invasion and/or perineural invasion (PNI), and positive lymph nodes were significantly associated with OS and RFS. Patients with a >95% pathologic response had a significantly improved OS (P = 0.003) and RFS (P = 0.002).

CONCLUSIONS

Treatment of locally advanced rectal cancer with preoperative CMT followed by TME can provide for a durable 10-year OS of 58% and RFS of 62%. Patients who achieve a >95% response to preoperative CMT have an improved long-term oncologic outcome, a novel finding that deserves further study.

Neoadjuvant treatment for locally advanced rectal carcinoma

Rectal cancer is one of the most common neoplasms of Western Countries. Overall mortality at 5 years is about 40%. This cancer is commonly diagnosed at a precocious stage, but because of local relapse and/or metastatic disease, only half of radically resected patients can be considered disease free. The value of adding radiotherapy to surgery in the treatment of patients with resectable rectal cancer has been assessed in trials using either preoperative or postoperative irradiation. Preoperative irradiation is more "dose-effective" than postoperative radiotherapy; that is, a higher dose is needed postoperatively to reduce rates of local recurrence to the same extent as preoperative radiation. Nevertheless, preoperative treatment has not been routinely recommended, mainly because it has not been shown to improve overall survival and because in some trials it has been associated with increased postoperative mortality. This paper critically reviews clinical trials of chemoradiotherapy on whether an optimal combination exists for locally advanced rectal cancer. Even if in the latest years, recent advances in surgery have improved the local control of disease, the next steps in rectal cancer care should aim at the improvement of local cure rates and the enhancement of systemic control. New approaches to CT treatment are necessary. Patient enrollment into rigorous and well-conducted clinical trials will generate new information regarding investigational therapies and it will offer improved therapies for patients with this disease.

Relationship between pathologic T-stage and nodal metastasis after preoperative chemoradiotherapy for locally advanced rectal cancer

BACKGROUND

We investigated the relationship between pathologic T-stage and mesorectal metastases after preoperative chemoradiotherapy (CRT) for clinical stage II to III rectal carcinoma.

METHODS

The records of consecutive patients with clinical stage II to III carcinoma of the mid or low rectum who underwent surgery after CRT were reviewed. Indications for preoperative CRT were cancer up to 11 cm from the anal verge, Eastern Cooperative Oncology Group performance status of 0 to 2, age 18 to 75 years, and clinical tumor-node-metastasis stage II or III.

RESULTS

The study group consisted of 235 patients (148 men and 87 women; median age, 61 years). The pretreatment tumor-node-metastasis stage was as follows: I, n = 1; II, n = 96; and III, n = 138. Radiotherapy was delivered at a median dose of 50.4 Gy. A pathologic complete response on the rectal wall was found in 24% of patients, and nodal metastases were found in 20% of patients. According to the pT stage, the rate of node positivity was 2% for pT0, 15% for pT1, 17% for pT2, 38% for pT3, and 33% for pT4 cases. At multivariate analysis, the best model for predicting pathologic node involvement included young age, positive pretreatment N status, and pT status. On considering pT stage alone, the odds ratio was in the region of 10 for pT1/2 and >20 for pT3/4 patients.

CONCLUSIONS

In patients with pT0 after preoperative CRT for clinical stage II to III mid or low rectal cancer, the risk of nodal metastases is very low. More conservative surgery (local excision) may be considered in these cases.

Complete pathologic response following preoperative chemoradiation therapy for middle to lower rectal cancer is not a prognostic factor for a better outcome

PURPOSE

The aim of this study was to evaluate factors associated with pathologic tumor response following pre-operative chemoradiation therapy, and the prognostic impact of pathologic response on overall and disease-free survival.

METHODS

Between 1994 and 2002, 132 patients underwent chemoradiation therapy followed by surgery for middle to lower rectal cancer. After excluding 26 cases (metastatic cancer, n = 13; nonradical surgery, n = 6; local excision procedure, n = 4; non-5-fluorouracil-based chemotherapy, n = 2; incomplete data on preoperative chemoradiation therapy regimen used, n = 1), the remaining 106 patients were included in the study. Variables considered were the following: age, gender, tumor location, pretreatment T and N stage, modality of 5-fluorouracil administration, total radiotherapy dose delivered, chemoradiation therapy regimen used (Regimen A: chemotherapy (bolus of 5-fluorouracil and leucovorin, days 1-5 and 29-33) + radiotherapy (45 Gy/25 F/1.8 Gy/F); Regimen B: chemotherapy (5-fluorouracil continuous venous infusion +/- weekly bolus of carboplatin or oxaliplatin) + radiotherapy (50.4 Gy/28 F/1.8 Gy/F)), time interval between completion of chemoradiation therapy and surgery, postoperative chemotherapy administration, surgical procedures, pT, pN, and pTNM stage, and response to chemoradiation therapy defined as tumor regression grade, scored from 1 (no tumor on surgical specimen) to 5 (absence of regressive changes). Statistical analysis was performed by means of logistic regression analysis (Cox's model for overall and disease-free survival).

RESULTS

Median age of the 106 patients was 60 (range, 31-79) years and the male:female ratio, 66:40. Median distance of tumor from the anal verge was 6 (range, 1-11) cm. Pretreatment TNM stage, available in 104 patients, was cT3T4N0, n = 41; cT2N1, n = 9; cT3N1, n = 39; and cT4N1, n = 17. The median radiotherapy dose delivered was 50.4 (range, 40-56) Gy; 58 patients received 5-fluorouracil by continuous venous infusion, and carboplatin with oxaliplatin was added to the chemotherapy schedule in 71 cases. Patients were given Regimen A in 47 cases and Regimen B in 59. The median interval between chemoradiation therapy and surgery was 42.5 (range, 19-136) days, and 94 patients underwent a sphincter-saving procedure. Tumor regression grade, available in 104 cases, was 1, n = 19; 2, n = 18; 3, n = 15; 4, n = 13; and 5, n = 39. At a median follow-up of 42 (range, 1-110) months, 11 patients had died, and 95 were alive. None of the patients had local recurrences, but 13 had distant recurrences. At logistic regression analysis, the chemoradiation therapy regimen used was the only independent predictor of tumor response following preoperative chemoradiation therapy (odds ratio = 0.29, 95% confidence interval = 0.13-0.67, P = 0.003). At Cox's regression analysis, pretreatment T stage was the only independent prognostic factor for both disease-free survival (relative risk = 7.13, 95% confidence interval = 2.3-21.8, P = 0.001) and overall survival (relative risk = 4.83, 95% confidence interval = 1.1-19.9, P = 0.029).

CONCLUSIONS

Tumor response following preoperative chemoradiation therapy is mainly related to the preoperative regimen used. For patients receiving preoperative chemoradiation therapy, pretreatment T stage, but not tumor response to preoperative chemoradiation therapy, is prognostic for outcome (both disease-free and overall survival).

Restaging after neoadjuvant chemoradiotherapy for rectal adenocarcinoma: role of F18-FDG PET

Multimodality treatment of loco-regional advanced rectal cancer has demonstrated to improve local control and overall survival. Proctoscopy, digital rectal examination (DRE), computer tomography (CT), endorectal ultrasound (ERUS), and magnetic resonance imaging (MRI) cannot correctly detect downstaging in rectal tumors after chemo radiation therapy (CRT). New imaging techniques, like 18F-FDG PET, may play some role in predicting the pathologic response to CRT before surgical resection. Aim of the present study was to further investigate the accuracy and predictive value of 18F-FDG PET in a large series of patients with rectal cancer treated with preoperative intensified CRT. Between January 2000 and December 2003, 81 patients with histologically proven adenocarcinoma in clinical stage II-III disease, according to criteria of TNM classification, were included in this study. All patients were submitted to diagnostic staging workup with DRE, proctoscopy with biopsy, ERUS, CT scan of the abdomen and pelvis or pelvic MRI plus liver ultrasonography, coloscopy or barium colonic enema. One month later the end of CRT all patients were submitted to diagnostic restaging work-up (DRW) and 18F-FDG PET. Surgery was performed 8-9 weeks after the end of CRT and pathologic stage was defined. Moreover a pathologic assessment of tumor regression was made with tumor regression grade score (TRG). PET correctly identified 22/28 (79% specificity) patients with complete pathologic response (pCR). However, sensitivity was 45% (24/53) while PPV, and NPV were equal to 77 and 43%, respectively. Total PET accuracy rate was 56%. PET sensitivity increased from 45 to 56% if the end-point was pCR, or TRG score, respectively. The best correlation was found between PET findings and pathologic stage (P <0.01) or TRG score (P <0.01). The accurate identification of rectal cancer patients with major pathological response after preoperative CRT further supports the necessity of designing prospective studies with new and more accurate was imaging technologies with the main object of offering conservative treatment in responder patients.

Long-term prognostic significance of extent of rectal cancer response to preoperative radiation and chemotherapy

OBJECTIVE

To determine whether selected clinicopathologic factors, including the extent of pathologic response to preoperative radiation and chemotherapy (RT +/- chemo), have an impact on long-term recurrence-free survival (RFS) in patients with locally advanced primary rectal cancer after optimal multimodality therapy.

SUMMARY BACKGROUND DATA

Although complete pathologic response to preoperative RT +/- chemo has been detected in up to 30% of rectal cancers, its significance on long-term outcome has not been widely reported. Previous retrospective studies evaluating clinical outcome in patients with complete or near-complete pathologic response documented good prognosis in this population but were limited by median follow-up in the range of 2 to 3 years.

METHODS

Sixty-nine patients with locally advanced (T(3-4) and/or N1) primary rectal cancer were prospectively identified. All were treated at one institution with preoperative RT to the pelvis (at least 4,500 cGy). Forty patients received concurrent preoperative 5-fluorouracil-based chemotherapy and 27 received both pre- and postoperative chemotherapy. Patients underwent resection 4 to 7 weeks after completion of RT. TNM stage, angiolymphatic or perineural invasion, and extent of response to preoperative RT +/- chemo were determined by pathologic evaluation. Adverse pathologic features were defined as the presence of angiolymphatic and/or perineural invasion. RFS at 5 years was determined by the Kaplan-Meier method.

RESULTS

With a median follow-up of 69 months, 5-year RFS was 79%. RFS was significantly worse for patients with aggressive pathologic features and positive nodal status identified in the postirradiated surgical specimen. Risk ratios for RFS were 3.68 for the presence of aggressive pathologic features and 4.64 for node-positive rectal cancers. In patients with greater than 95% rectal cancer response to preoperative RT +/- chemo, only one patient has died as a consequence of cancer, another has died of an unrelated cause, and the remainder were free of disease with a minimum follow-up of 47 months.

CONCLUSIONS

These data suggest that a marked response to preoperative RT +/- chemo may be associated with good long-term outcome but was not predictive of RFS. The presence of poor histopathologic features and positive nodal status are the most important prognostic indicators after neoadjuvant therapy.

Preoperative chemoradiation in patients with resectable rectal cancer: results on tumor response

BACKGROUND

There is no consensus about the role of preoperative radiotherapy (RT) and chemotherapy (CT) in patients with resectable cancer of the distal rectum. This study analyzed the local clinical and pathologic response in patients receiving preoperative RT/CT for rectal cancer.

METHODS

Thirty-two consecutive patients with a palpable adenocarcinoma of the rectum received preoperative RT (45 Gy in 25 fractions over 5 weeks) plus continuous chemotherapy with doxifluridine and leucovorin or 5-fluorouracil by continuous intravenous infusion during RT. Surgery was performed 8 weeks later. The Wilcoxon and chi(2) tests were used for data analysis.

RESULTS

Twelve patients had mild gastrointestinal toxicity, only one of whom required interruption of therapy. The tumor shrank to 57.8% of its original size, and at the echoendoscopy (u) there was a 58.7% decrease of the maximum diameter (P <.001). Downstaging from uT3 and uT2 to <uT3 and <uT2, respectively, occurred in 41.6% of patients (P =.0020). Total and major regression of the tumor at the histopathologic examination occurred in 12.5% and 50% of patients.

CONCLUSIONS

Local response to preoperative RT/CT was highly satisfactory and allowed conservative surgery in 81% of patients. Optimization of the combined therapy could achieve even better results.

Cost-effectiveness of endoscopic ultrasonography in the evaluation of proximal rectal cancer

OBJECTIVE

Clinical trials demonstrate the superiority of preoperative over postoperative radiotherapy (XRT) in diminishing rates of local recurrence of transmurally infiltrating (T3/4) rectal tumors. The dosage and cost of preoperative XRT are less than postoperative XRT. The economic and health impact of transrectal endoscopic ultrasound (EUS) on rectal cancer management has not been described. The aim of this study was to apply a decision analysis model to compare the cost-effectiveness of three staging strategies in the evaluation of nonmetastatic proximal rectal cancer: abdominal and pelvic CT versus abdominal CT plus EUS versus abdominal CT plus pelvic magnetic resonance imaging.

METHODS

A decision model was designed using DATA Version 3.5 (TreeAge Software, Williamstown, MA), taking as entry criteria nonmetastatic proximal rectal cancer as determined by abdominal CT. In each arm, detection of transmural invasion prompted preoperative XRT. Baseline probabilities were varied through plausible ranges using sensitivity analysis. Cost inputs were based on Medicare professional plus facility fees. Endpoints were cost of treatment per patient and tumor recurrence-free rates. Cost-effectiveness (cost per prevention of local recurrence) and incremental cost-effectiveness ratios were calculated.

RESULTS

For proximal rectal tumors, evaluation with abdominal CT plus EUS is the most cost-effective approach ($24,468/yr) compared with abdominal CT plus pelvic magnetic resonance imaging ($24,870) and CT alone ($26,076). Both the magnetic resonance imaging- and CT-only approaches were dominated (i.e., more costly and less effective).

CONCLUSIONS

Abdominal CT plus EUS is the most cost-effective staging strategy for nonmetastatic proximal rectal cancer. Staging strategies incorporating EUS improve treatment allocation by achieving more accurate T staging, thereby optimizing the benefit of preoperative XRT to more advanced tumors.

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

BACKGROUND

Up to 30% of patients with locally advanced rectal cancer have a complete clinical or pathologic response to neoadjuvant chemoradiation. This study analyzes complete clinical and pathologic responders among a large group of rectal cancer patients treated with neoadjuvant chemoradiation.

METHODS

From 1987 to 2000, 141 consecutive patients with biopsy-proven, locally advanced rectal cancer were treated with preoperative 5-fluorouracil-based chemotherapy and radiation. Clinical restaging after treatment consisted of proctoscopic examination and often computed tomography scan. One hundred forty patients then underwent operative resection, with results tracked in a database. Standard statistical methods were used to examine the outcomes of those patients with complete clinical or pathologic responses.

RESULTS

No demographic differences were detected between either clinical complete and clinical partial responders or pathologic complete and pathologic partial responders. The positive predictive value of clinical restaging was 60%, and accuracy was 82%. By use of the Kaplan-Meier life table analysis, clinical complete responders had no advantage in local recurrence, disease-free survival, or overall survival rates when compared with clinical partial responders. Pathologic complete responders also had no recurrence or survival advantage when compared with pathologic partial responders. Of the 34 pathologic T0 tumors, 4 (13%) had lymph node metastases.

CONCLUSIONS

Clinical assessment of complete response to neoadjuvant chemoradiation is unreliable. Micrometastatic disease persists in a proportion of patients despite pathologic complete response. Observation or local excision for patients thought to be complete responders should be undertaken with caution.

P27kip1 expression is associated with tumor response to preoperative chemoradiotherapy in rectal cancer

BACKGROUND

Our aim was to ascertain whether or not the response to preoperative chemoradiotherapy for rectal cancer is associated with p27kip1 and p53 protein expression.

METHODS

Thirty-eight patients (27 male, 11 female) with a mean age of 59 years (age range 33-87) and stage II-III rectal cancer received preoperative chemoradiotherapy (45-50.4 Gy; 5-FU 350 mg/m2/day and leucovorin 10 mg/m2/day). Thirty-one underwent low anterior resection; seven underwent abdominoperineal excision. Endoscopic tumor biopsies, performed before adjuvant therapy, were evaluated for: histologic type, tumor differentiation, mitotic index, and p27kip1 and p53 protein expression which were immunohistochemically determined. p53 expression was graded as: a) absent or present in < or =10% of tumor cells; b) present in 11-25%; c) present in 26-75%; and d) present in >75% of tumor cells. p27kip1 expression was assessed using both light microscopy (percent of stained cells x10 HPF) and cytometry with an image analysis workstation. Tumor response, ascertained with histology, was classified using a scale from 0 (no response) to 6 (complete pathologic response).

RESULTS

The mitotic index for the endoscopic biopsies was low in 14 cases, moderate in 17 cases, and high in 7 cases. p53 protein expression was found in 21 (a), 3 (b), 3 (c), and 11 (d) cases. The mean percentage of cells expressing the p27kip1 protein was 34 (range 0-77.14%). A close correlation was found between cytometric and light microscopy findings for p27kip1 (r2 = 0.92, P = .0001). Tumor differentiation was good in 5 cases, poor in 2 cases, and moderate in the remaining 31 cases. While the response to adjuvant therapy was good/complete in 25 (65.78%) cases, it was absent/poor in 13 (34.21%) cases. Univariate analysis associated type of adjuvant therapy (chemoradiotherapy, P = .0428) and p27kip1 protein lower expression (P = .0148) with a poor response to adjuvant treatment. Stepwise linear regression found overexpression of p53 and p27kip1 and young age to be independent variables that were linked to a good response to adjuvant therapy.

CONCLUSIONS

Lack of p27kip1 and p53 protein expression in rectal cancer is associated with a poor response to preoperative adjuvant therapy.

Neoadjuvant chemoradiation for rectal cancer: analysis of clinical outcomes from a 13-year institutional experience

OBJECTIVE

To examine clinical outcomes in patients receiving neoadjuvant chemoradiation for locally advanced rectal adenocarcinoma.

SUMMARY BACKGROUND DATA

Preoperative radiation therapy, either alone or in combination with 5-fluorouracil-based chemotherapy, has proven both safe and effective in the treatment of rectal cancer. However, data are lacking regarding which subgroups of patients benefit from the therapy in terms of decreased local recurrence and increased survival rates.

METHODS

A retrospective chart review was performed on 141 consecutive patients who received neoadjuvant chemoradiation (5-fluorouracil +/- cisplatin and 4,500-5,040 cGy) for biopsy-proven locally advanced adenocarcinoma of the rectum. Surgery was performed 4 to 8 weeks after completion of chemoradiation. Standard statistical methods were used to analyze recurrence and survival.

RESULTS

Median follow-up was 27 months, and mean age was 59 years (range 28-81). Mean tumor distance from the anal verge was 6 cm (range 1-15). Of those staged before surgery with endorectal ultrasound or magnetic resonance imaging, 57% of stage II patients and 82% of stage III patients were downstaged. The chemotherapeutic regimens were well tolerated, and resections were performed on 140 patients. The percentage of sphincter-sparing procedures increased from 20% before 1996 to 76% after 1996. On pathologic analysis, 24% of specimens were T0. However, postoperative pathologic T stage had no effect on either recurrence or survival. Positive lymph node status predicted increased local recurrence and decreased survival.

CONCLUSIONS

Neoadjuvant chemoradiation is safe, effective, and well tolerated. Postoperative lymph node status is the only independent predictor of recurrence and survival.