Role of Preoperative Local and Distant Staging in Rectal Cancer

Establishment and characterization of McA-RH7777 cells using virus-mediated stable overexpression of enhanced green fluorescent protein

Hepatocellular carcinoma (HCC), the most common primary tumor of the liver, has a poor prognosis, rapid progression. The aim of the current study was to establish a stable lentiviral expression vector for enhanced green fluorescent protein (EGFP) and to evaluate biological characteristics on HCC growth and migration following transfection of HCC cells with EGFP. McA-RH7777 cells were transfected with EGFP overexpression lentiviral vector. Cell activity and mobility were monitored with a Cell-IQ Analyzer. Transwell assays were performed to detect invasiveness and flow cytometry was performed for cell cycle analysis. A subcutaneous tumor rat model was established to analyze the stability of fluorescent protein expression. The result suggested no significant differences between wild-type and EGFP-overexpressing McA-RH7777 cells with regards to cell proliferation, activity, mobility, invasiveness and cell cycle. Green fluorescence was detected over 108 days of culturing. The subcutaneous tumor rat model demonstrated that EGFP expression had no influence on tumor growth and long-term expression was stable. The stable EGFP expression of the HCC transplanted tumor rat model may share biological characteristics with human liver cancer. The model established in the current study may be suitable for various applications, including research focusing on liver cancer metastasis and recurrence, interventional therapy, imaging diagnosis and drug screenings.

Tailored rectal cancer treatment--a time for implementing contemporary prognostic factors?

AIM

To report data supporting the development of tailored treatment strategies for rectal cancer.

METHOD

A comprehensive review of the literature on the impact of prognostic factors cur-rently not included in international guidelines in rectal cancer management.

RESULTS

There is considerable variation in treatment guidelines for rectal cancer worldwide, especially for Stage II and Stage III disease. Long-term side effects of chemoradiotherapy are not considered in any guideline. Detailed knowledge, and the prognostic impact, of the circumferential resection margin, tumour grade and venous invasion should be factored into the development of a treatment strategy.

CONCLUSION

Factors additional to the TNM system should improve decision making for contemporary rectal cancer treatment. Optimized radiological and pathological evaluations, and a focus on detailed clinical factors, should be the basis for treatment decisions. International guidelines should consider all known prognostic factors for long-term oncological and functional outcomes.

Stage and size using magnetic resonance imaging and endosonography in neoadjuvantly-treated rectal cancer

AIM: To assess the stage and size of rectal tumours using 1.5 Tesla (1.5T) magnetic resonance imaging (MRI) and three-dimensional (3D) endosonography (ERUS).

METHODS: In this study, patients were recruited in a phase I/II trial of neoadjuvant chemotherapy for biopsy-proven rectal cancer planned for surgical resection with or without preoperative radiotherapy. The feasibility and accuracy of 1.5T MRI and 3D ERUS were compared with the histopathology of the fixed surgical specimen (pathology) to determine the stage and size of the rectal cancer before and after neoadjuvant chemotherapy. A Philips Intera 1.5T with a cardiac 5-channel synergy surface coil was used for the MRI, and a B-K Medical Falcon 2101 EXL 3D-Probe was used at 13 MHz for the ERUS. Our hypothesis was that the staging accuracy would be the same when using MRI, ERUS and a combination of MRI and ERUS. For the combination, MRI was chosen for the assessment of the lymph nodes, and ERUS was chosen for the assessment of perirectal tissue penetration. The stage was dichotomised into stage I and stage II or greater. The size was measured as the supero-inferior length and the maximal transaxial area of the tumour.

RESULTS: The staging feasibility was 37 of 37 for the MRI and 29 of 36 for the ERUS, with stenosis as a limiting factor. Complete sets of investigations were available in 18 patients for size and 23 patients for stage. The stage accuracy by MRI, ERUS and the combination of MRI and ERUS was 0.65, 0.70 and 0.74, respectively, before chemotherapy and 0.65, 0.78 and 0.83, respectively, after chemotherapy. The improvement of the post-chemotherapy staging using the combination of MRI and ERUS compared with the staging using MRI alone was significant (P = 0.046). The post-chemotherapy understaging frequency by MRI, ERUS and the combination of MRI and ERUS was 0.18, 0.14 and 0.045, respectively, and these differences were non-significant. The measurements of the supero-inferior length by ERUS compared with MRI were within 1.96 standard deviations of the difference between the methods (18 mm) for tumours smaller than 50 mm. The agreement with pathology was within 1.96 standard deviations of the difference between imaging and pathology for all tumours with MRI (15 mm) and for tumours that did not exceed 50 mm with ERUS (22 mm). Tumours exceeding 50 mm in length could not be reliably measured by ERUS due to the limit in the length of each recording.

CONCLUSION: MRI is preferable to use when assessing the size of large or stenotic rectal tumours. However, staging accuracy is improved by combining MRI with ERUS.

Neoadjuvant chemotherapy evaluation by MRI volumetry in rectal cancer followed by chemoradiation and total mesorectal excision: Initial experience

PURPOSE

To evaluate rectal cancer volumetry in predicting initial neoadjuvant chemotherapy response.

MATERIALS AND METHODS

Sixteen consecutive patients who underwent neoadjuvant chemotherapy (CX) before chemoradiotherapy (CRT) and surgery were enrolled in this retrospective study. Tumor volume was evaluated at the first magnetic resonance imaging (MRI), after CX and after CRT. Tumor volume regression (TVR) and downstaging were compared with histological results according to Tumor Regression Grade (TRG) to assess CX and CRT response, respectively.

RESULTS

The mean tumor volume was 132 cm(3) ± 166 before and 56 cm(3) ± 71 after CX. TVR after CX was significantly different between patients with poor histologic response (TRG1/2) and those with good histologic response (TRG3/4) (P = 0.001). An optimal cutoff of TVR >68% (area under the curve [AUC]: 0.9, 95% confidence interval [CI]: 0.65-0.98, P = 0.0001) to predict good histology response after CX was assessed by receiver operating characteristic curve. According to previous data and this study, we defined 70% as the best cutoff values according to sensitivity (86%), specificity (100%) of TVR for predicting good histology response. In contradistinction, MRI downstaging was associated with TRG only after CRT (P = 0.04).

CONCLUSION

Our pilot study showed that MRI volumetry can predict early histological response after CX and before CRT. MRI volumetry could help the clinician to distinguish early responders in order to aid appropriate individually tailored therapies.

Transrectal ultrasound and magnetic resonance imaging measurement of extramural tumor spread in rectal cancer

AIM: To evaluate the agreement between transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) in classification of ≥ T3 rectal tumors.

METHODS: From January 2010 to January 2012, 86 consecutive patients with ≥ T3 tumors were included in this study. The mean age of the patients was 66.4 years (range: 26-91 years). The tumors were all ≥ T3 on TRUS. The sub-classification was defined by the penetration of the rectal wall: a: 0 to 1 mm; b: 1-5 mm; c: 6-15; d: > 15 mm. Early tumors as ab (≤ 5 mm) and advanced tumors as cd (> 5 mm). All patients underwent TRUS using a 6.5 MHz transrectal transducer. The MRI was performed with a 1.5 T Philips unit. The TRUS findings were blinded to the radiologist performing the interpretation of the MRI images and measuring the depth of extramural tumor spread.

RESULTS: TRUS found 51 patients to have an early ≥ T3 tumors and 35 to have an advanced tumor, whereas MRI categorized 48 as early ≥ T3 tumors and 38 as advanced tumors. No patients with tumors classified as advanced by TRUS were found to be early on MRI. The kappa value in classifying early versus advanced T3 rectal tumors was 0.93 (95% CI: 0.85-1.00). We found a kappa value of 0.74 (95% CI: 0.63-0.86) for the total sub-classification between the two methods. The mean maximal tumor outgrowth measured by TRUS, 5.5 mm ± 5.63 mm and on MRI, 6.3 mm ± 6.18 mm, P = 0.004. In 19 of the 86 patients the following CT scan or surgery revealed distant metastases; of the 51 patients in the ultrasound ab group three (5.9%) had metastases, whereas 16 (45.7%) of 35 in the cd group harbored distant metastases, P = 0.00002. The odds ratio of having distant metastases in the ultrasound cd group compared to the ab group was 13.5 (95% CI: 3.5-51.6), P = 0.00002. The mean maximal ultrasound measured outgrowth was 4.3 mm (95% CI: 3.2-5.5 mm) in patients without distant metastases, while the mean maximal outgrowth was 9.5 mm (95% CI: 6.2-12.8 mm) in the patients with metastases, P = 0.00004. Using the MRI classification three (6.3%) of 48 in the MRI ab group had distant metastases, while 16 (42.1%) of the 38 in the MRI cd group, P = 0.00004. The MRI odds ratio was 10.9 (95% CI: 2.9-41.4), P = 0.00008. The mean maximal MRI measured outgrowth was 4.9 mm (95% CI: 3.7-6.1 mm) in patients without distant metastases, while the mean maximal outgrowth was 11.5 mm (95% CI: 7.8-15.2 mm) in the patients with metastases, P = 0.000006.

CONCLUSION: There is good agreement between TRUS and MRI in the pretreatment sub-classification of ≥ T3 tumors. Distant metastases are more frequent in the advanced group.

Individualized magnetic resonance imaging-based neoadjuvant chemoradiation for middle and lower rectal carcinoma

AIM

In most institutions neoadjuvant chemoradiation for middle and lower rectal carcinoma is currently given to patients with tumours of clinical stages II or III (cT3,4 and/or N1,2). The possibility of a reduction in the use of neoadjuvant chemoradiation by an individualized magnetic resonance imaging (MRI)-based indication for neoadjuvant chemoradiation was analysed.

METHOD

Assessment of the pathological and oncological principles indicating for neoadjuvant treatment was used to determine the prognostic importance of the distance between the tumour and the circumferential resection margin and pretherapeutic assessment using modern MRI.

RESULTS

Based on the results of pretreatment MRI scanning, a proposal is presented for the treatment of middle and lower rectal carcinoma with neoadjuvant chemoradiation. Adopting this proposal, the frequency of neoadjuvant chemoradiation decreased from 70% to 35% and the early and late adverse effects of this therapy were reduced. In contrast, the expected locoregional recurrence rate increased from 6% to 11% if all quality criteria were met and to 18% if not.

CONCLUSION

An MRI-based indication for neoadjuvant chemoradiation is justified only for centres with regular quality assurance of MRI, surgery, radiotherapy and pathology. The proposal needs confirmation by long-term follow up and by prospective studies with larger numbers of patients.

Magnetic resonance imaging (MRI) in rectal cancer: a comprehensive review

Magnetic resonance imaging (MRI) has established itself as the primary method for local staging in patients with rectal cancer. This is due to several factors, most importantly because of the ability to assess the status of circumferential resection margin. There are several newer developments being introduced continuously, such as diffusion-weighted imaging and imaging with 3 T. Assessment of loco-regional lymph nodes has also been investigated extensively using different approaches, but more work needs to be done. Finally, evaluation of tumours during or after preoperative treatment is becoming an everyday reality. All these new aspects prompt a review of the most recent advances and opinions. In this review, a comprehensive overview of the current status of MRI in the loco-regional assessment and management of rectal cancer is presented. The findings on MRI and their accuracy are reviewed based on the most up-to-date evidence. Optimisation of MRI acquisition and relevant regional anatomy are also presented, based on published literature and our own experience.

Endorectal ultrasound: its role in the diagnosis and treatment of rectal cancer

With development over the past 25 years of new surgical techniques and neoadjuvant therapy regimens for rectal cancer, physicians now have a range of treatment options that minimize morbidity and maximize the potential for cure. Accurate pretreatment staging is critical, ensuring adequate therapy and preventing overtreatment. Many options exist for staging primary rectal cancer. However, endorectal ultrasound (ERUS) remains the most attractive modality. It is an extension of the physical examination, and can be performed easily in the office. It is cost effective and is generally well tolerated by the patient, without need for general anesthesia. The authors discuss the data currently available on ERUS, including its accuracy and limitations, as well as the technical aspects of performing ERUS and interpreting the results. They also discuss new ultrasound technologies, which may improve rectal cancer staging in the future.

Role of tumor size in the pre-operative management of rectal cancer patients

Background

Clinical management of rectal cancer patients relies on pre-operative staging. Studies however continue to report moderate degrees of over/understaging as well as inter-observer variability. The aim of this study was to determine the sensitivity, specificity and accuracy of tumor size for predicting T and N stages in pre-operatively untreated rectal cancers.

Methods

We examined a test cohort of 418 well-documented patients with pre-operatively untreated rectal cancer admitted to the University Hospital of Basel between 1987 and 1996. Classification and regression tree (CART) and logistic regression analysis were carried out to determine the ability of tumor size to discriminate between early (pT1-2) and late (pT3-4) T stages and between node-negative (pN0) and node-positive (pN1-2) patients. Results were validated by an external patient cohort (n = 28).

Results

A tumor diameter threshold of 34 mm was identified from the test cohort resulting in a sensitivity and specificity for late T stage of 76.3%, and 67.4%, respectively and an odds ratio (OR) of 6.67 (95%CI:3.4-12.9). At a threshold value of 29 mm, sensitivity and specificity for node-positive disease were 94% and 15.5%, respectively with an OR of 3.02 (95%CI:1.5-6.1). Applying these threshold values to the validation cohort, sensitivity and specificity for T stage were 73.7% and 77.8% and for N stage 50% and 75%, respectively.

Conclusions

Tumor size at a threshold value of 34 mm is a reproducible predictive factor for late T stage in rectal cancers. Tumor size may help to complement clinical staging and further optimize the pre-operative management of patients with rectal cancer.

Regional lymph node metastasis and locoregional recurrence of rectal carcinoma in the era of TME [corrected] surgery. Implications for treatment decisions

BACKGROUND AND AIMS

For rectal carcinoma treated according to the concept of total mesorectal excision (TME surgery), the independent influence of regional lymph node metastasis on the locoregional recurrence risk is still in discussion. A reliable assessment of this risk is important for an individualised selective indication for neoadjuvant radio-/radiochemotherapy.

METHODS

Analysis of literature, especially of the last 20 years, and consideration of pathological and oncological basic research. Multivariate analysis of data of the Erlangen Registry of Colorectal Carcinoma.

RESULTS

The clinical assessment of the pretherapeutic regional lymph node status by the present available imaging methods is still unreliable. The analysis of the association between pretherapeutic regional lymph node status and locoregional recurrence risk has to be based on follow-up data of patients treated by primary surgery and has to be distinguished between patients treated by conventional and optimised quality-assured TME surgery, respectively. Data from Erlangen show an increase of the local recurrence risk for patients with at least four involved regional lymph nodes.

CONCLUSIONS

For patients with at least four involved regional lymph nodes, a neoadjuvant radiochemotherapy may be indicated. However, today, the pretherapeutic diagnosis is uncertain and results in overtherapy in 40%. Thus, in case of positive lymph node findings by imaging methods, the benefits and risk of neoadjuvant therapy in such situations should always be discussed with the patient in the sense of informed consent and shared decision.

Preoperative staging with chest CT in patients with colorectal carcinoma: not as a routine procedure

Background

Preoperative staging of patients with colorectal carcinoma (CRC) has the potential benefit of altering treatment options when metastases are present. The clinical value of chest computed tomography (CT) in staging remains unclear.

Materials and Methods

All patients who undergo colorectal surgery in our hospital are prospectively registered, including patient, treatment, and histopathological characteristics; outcome; and follow-up. Since January 2007, routine preoperative staging CT of chest and abdomen for patients with CRC has been performed as part of our regional guidelines. In this observational cohort study, an analysis on outcome was done after inclusion of 200 consecutive patients.

Results

Synchronous metastases were present in 60 patients (30%). Staging chest CT revealed pulmonary metastases in 6 patients, with 1 false positive finding. In 50 patients indeterminate lesions were seen on chest CT (25%). These were diagnosed during follow-up as true metastases (n = 8), bronchus carcinoma (n = 2), benign lesions (n = 25), and remaining unknown (n = 15). Ultimately, synchronous pulmonary metastases were diagnosed in 13 patients (7%), in 6 patients confined to the lung (3%). In none of the patients the treatment plan for the primary tumor was changed based on the staging chest CT.

Conclusion

The low incidence of pulmonary metastases and minimal consequences for the treatment plan limits the clinical value of routine staging chest CT before operation. It has several disadvantages such as costs, radiation exposure, and prolonged uncertainty because of the frequent finding of indeterminate lesions. Based on this study, a routine staging chest CT in CRC patients is not advocated.

Multidisciplinary Rectal Cancer Management: 2nd European Rectal Cancer Consensus Conference (EURECA-CC2)

BACKGROUND AND PURPOSE

During the first decade of the 21st century a number of important European randomized studies were published. In order to help shape clinical practice based on best scientific evidence from the literature, the International Conference on 'Multidisciplinary Rectal Cancer Treatment: Looking for an European Consensus' (EURECA-CC2) was organized in Italy under the endorsement of European Society of Medical Oncology (ESMO), European Society of Surgical Oncology (ESSO), and European Society of Therapeutic Radiation Oncology (ESTRO).

METHODS

Consensus was achieved using the Delphi method. The document was available to all Committee members as a web-based document customized for the consensus process. Eight chapters were identified: epidemiology, diagnostics, pathology, surgery, radiotherapy and chemotherapy, treatment toxicity and quality of life, follow-up, and research questions. Each chapter was subdivided by a topic, and a series of statements were developed. Each member commented and voted, sentence by sentence thrice. Sentences upon which an agreement was not reached after voting round # 2 were openly debated during a Consensus Conference in Perugia (Italy) from 11 December to 13 December 2008. A hand-held televoting system collected the opinions of both the Committee members and the audience after each debate. The Executive Committee scored percentage consensus based on three categories: "large consensus", "moderate consensus", and "minimum consensus".

RESULTS

The total number of the voted sentences was 207. Of the 207, 86% achieved large consensus, 13% achieved moderate consensus, and only 3 (1%) resulted in minimum consensus. No statement was disagreed by more than 50% of the members. All chapters were voted on by at least 75% of the members, and the majority was voted on by >85%.

CONCLUSIONS

This Consensus Conference represents an expertise opinion process that may help shape future programs, investigational protocols, and guidelines for staging and treatment of rectal cancer throughout Europe.

[Newer techniques in diagnostic imaging of colorectal carcinoma]

A wide spectrum of nowadays availible radiological and imaging methods in the diagnostic evaluation of patients with colorectal cancer enabled not only the improvement of primary colorectal malignancy detection, precise staging, regional involvement and metastatic spread assessment, but also the posttherapeutical estimation and follow-up. Having in mind that the exact diagnostic assessment of colorectal carcinoma by use of different imaging modalities still raises a lots of contradictories, in this report we have tried to present the possibilities of newer imaging techniques in the diagnostic evaluation of the patients with colorectal cancer.

Preoperative staging of rectal tumors: comparison of endorectal ultrasound, hydro-CT, and high-resolution endorectal MRI

AIM

The aim of this study was to compare transrectal ultra-sound (TRUS), hydro-computed tomography (hydro-CT), and endorectal magnetic resonance imaging (MRI) in the preoperative staging of rectal cancer.

PATIENTS AND METHODS

23 patients with rectal adenocarcinoma underwent TRUS, hydro-CT, and MRI (1 Tesla) with endorectal coil. The results were correlated with the histopathological findings based on the TNM classification.

RESULTS

T staging with TRUS, hydro-CT, and endorectal MRI correlated with the histopa-thological findings in 83% of patients (19/23). Tumors were overestimated by TRUS in 2/23 patients, by CT in 3/23, and by MRI in 3/23 patients. Tumor size was underestimated by TRUS in 2 patients, by CT and MRI in 1 case each. Local lymphatic node involvement was correctly diagnosed with CT and MRI in 87% and 83%, respectively. Using TRUS, false-negative results in the staging of lymph node involvement were seen in 3/23 patients, whereas 1 patient was over-staged. Using hydro-CT as well as endorectal MRI, overstaging of the local lymph nodes took place in 2/23 patients.

CONCLUSION

All methods are limited because peritumoral inflammation cannot be precisely distinguished from infiltration by the tumor. Correct lymph node staging is hampered in advanced disease using TRUS. In these patients, further cross-sectional imaging may be required.

Tumor response to neoadjuvant chemoradiation in rectal cancer: predictor for surgical morbidity?

BACKGROUND

Increasing the rate of pathological complete remissions after neoadjuvant chemoradiation of rectal cancer has become a strategy to further improve the long-term oncological outcome of patients. This report evaluates the influence of preoperative intensified radiochemotherapy on the rate and outcome of surgical complications.

MATERIALS AND METHODS

Patients with primary rectal cancer at stages cT3/4cNx or N+ without metastasis were preoperatively treated either with capecitabine and irinotecan or with capecitabine, irinotecan and ceutximab with a concurrent radiation (50.4 Gy). Surgery was scheduled 4-7 weeks after completion of the chemoradiation. Perioperative complications were prospectively documented during the patient's hospital stay.

RESULTS

Fifty-nine patients (median age 60; male/female: 46/13) undergoing surgery at a single center were analysed. The median distance of the tumour from the dentate line was 5 cm. The operations performed were low anterior resection (n=45), Hartmann's procedure (n=4) and abdominoperineal resection (n=10). Total mesorectal excision with R0-resection was accomplished in all but one patients. Histopathological regression was described in four grades (0-3) as defined by the Japanese Society for Cancer of the Colon and Rectum. Tumors were called major responsive when assigned to the regression grades 3 or 2, and minor or nonresponsive at regression grades 1 or 0. In total, 33 patients (55.9%) had a regression grade 2 or 3. Among them, 12 patients showed a pathological complete response without any residual cancer cell (20.3%). Seven out of 45 patients (15.5%) with sphincter-preserving surgery suffered from suture breakdown; they all had previously shown a major response of the resected tumor. Two of them died during the hospital stay.

CONCLUSIONS

While in general, patients undergoing neoadjuvant intensified treatment suffer from a slight increase in surgical complications, this is markedly enhanced in patients with good treatment responses. Our results underline the oncological benefit of intensified neoadjuvant chemoradiation, but the severity of complications in low rectal anastomosis of patients with good response after neoadjuvant therapy should alert surgeons and oncologists.

The role of PET in target localization for radiotherapy treatment planning

Positron emission tomography (PET) is currently accepted as an important tool in oncology, mostly for diagnosis, staging and restaging purposes. It provides a new type of information in radiotherapy, functional rather than anatomical. PET imaging can also be used for target volume definition in radiotherapy treatment planning. The need for very precise target volume delineation has arisen with the increasing use of sophisticated three-dimensional conformal radiotherapy techniques and intensity modulated radiation therapy. It is expected that better delineation of the target volume may lead to a significant reduction in the irradiated volume, thus lowering the risk of treatment complications (smaller safety margins). Better tumour visualisation also allows a higher dose of radiation to be applied to the tumour, which may lead to better tumour control. The aim of this article is to review the possible use of PET imaging in the radiotherapy of various cancers. We focus mainly on non-small cell lung cancer, lymphoma and oesophageal cancer, but also include current opinion on the use of PET-based planning in other tumours including brain, uterine cervix, rectum and prostate.

Preoperative assessment of rectal cancer stage: state of the art

Rectal cancer is one of the most common tumors worldwide; it accounts for approximately 25-30% of cancers arising in the large bowel. Owing to greater distribution of screening programs and better attention from both patients and General Practitioners to this disease, in recent years we have observed an increasing number of cases diagnosed in the early stages, with a consequent better prognosis. The improved 5-year survival is also partially due to better, and more accurate, diagnostic techniques and to more curative treatments. In this review, the authors analyze and discuss the more recent diagnostic techniques for an accurate preoperative staging of rectal cancer, highlighting each method's advantages and limits for their routine use in clinical practice.