Preoperative radiotherapy for rectal cancer: implications for surgeons, pathologists and radiologists

Identification of Optimal Parameters for Assessing Lymph Node Status of Patients with Esophageal Squamous Cell Carcinoma After Neoadjuvant Chemoradiotherapy

BACKGROUND

This study aimed to compare the prognostic discrimination power of pretreatment pathologic N stage (prepN), lymph node tumor regression grade (LNTRG), and posttreatment pathologic N (ypN) category for esophageal squamous cell carcinoma (ESCC) patients who received neoadjuvant chemoradiotherapy (nCRT) plus surgery.

METHODS

The study reviewed 187 ESCC patients from two medical centers who underwent nCRT plus surgery. Pathologic LNTRG was defined by the proportion of viable tumor area within the tumor bed in lymph nodes (LNs). An average LNTRG then was calculated by averaging the tumor regression grade (TRG) score of all resected LNs. Lymph nodes containing regression changes or vital tumor cells were used for interpretation of the prepN stage, which reflects the estimated number of originally involved LNs.

RESULTS

The ypN, prepN, and LNTRG categories had significant prognostic stratification power (p < 0.001, log-rank test). Multivariable cox regression showed that all three categories were independent prognostic factors of disease-free survival (DFS) (p < 0.05). The LNTRG category showed a better prognostic value for DFS prediction than the ypN and prepN categories (Akaike information criterion [AIC]: LNTRG [933.69], ypN [937.56], prepN [937.45]). Additionally, the superior predictive capacity of the LNTRG category was demonstrated by decision curve analysis. Similar results were discovered for patients with remaining diseased LNs.

CONCLUSIONS

The three staging categories had prognostic relevance for DFS, with the LNTRG category seeming to have better prognostic indication power. Comprehensive consideration of the ypN status, prepN status, and LN regression may allow for better prognostic stratification of patients.

Dynamic contrast-enhanced magnetic resonance imaging for evaluating early response to radiosurgery in patients with vestibular schwannoma

PURPOSE

This study aimed to use dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to evaluate early treatment response in vestibular schwannoma (VS) patients after radiosurgery.

METHODS

Twenty-four VS patients who underwent gamma knife radiosurgery were prospectively followed up for at least four years. DCE-MRI sequences, in addition to standard MRI protocol, were obtained prior to radiosurgery, at 3 and 6 months. Conventionally, treatment responses based on tumor volume changes were classified as regression or stable (RS), transient tumor enlargement (TTE), and continuous tumor enlargement (CTE). DCE-MRI parameters, such as K^trans, K_ep and V_e, were compared according to follow-up periods and between groups. The diagnostic performance was tested using receiver operating characteristic (ROC) curves.

RESULTS

Changes in tumor volume were as follows at the last 48 months of follow-up: RS in 11 patients (45.8%), TTE in 10 patients (41.7%), and CTE in three patients (12.5%). The median time required to distinguish TTE from CTE using conventional MRI was 12 months (range 9-18). The K^trans and V_e were significantly decreased in patients with RS and TTE at 3 and 6 months, but did not differ significantly in patients with CTE. There were no significant differences in K^trans and V_e between patients with RS and TTE at 3 and 6 months. Both K^trans and V_e demonstrated high diagnostic performance in evaluating early treatment response to radiosurgery in patients with VS.

CONCLUSION

DCE-MRI may aid in the monitoring and early prediction of treatment response in patients with VS following radiosurgery.

Poor response at restaging MRI and high incomplete resection rates of locally advanced mucinous rectal cancer after chemoradiation therapy

AIM

Mucinous carcinoma is a histological subtype of rectal cancer and has been associated with a poor response to neoadjuvant chemoradiotherapy (CRT). The primary aim of this study was to analyse the response on MRI of mucinous locally advanced rectal cancer (LARC) after CRT compared to regular adenocarcinoma.

METHOD

Patients with LARC (defined as cT4 and/or cN2), who underwent CRT followed by restaging MRI and surgery in two tertiary referral hospitals were retrospectively included in the study. Pre- and post-treatment MRI was reviewed by an experienced abdominal radiologist.

RESULTS

A total of 102 patients, of whom 29 were diagnosed with mucinous carcinoma, were included for analysis. At restaging MRI, adenocarcinoma patients demonstrated significantly less clinical involvement of the mesorectal fascia (37% vs. 62%, P = 0.003) while this was not demonstrated in mucinous carcinoma patients (86% vs. 97%, P = 0.16). Significant downstaging after CRT in adenocarcinoma patients (P = 0.01) was seen while, in mucinous carcinoma patients, no downstaging after CRT (P = 0.89) was seen. Pathology revealed significantly higher rates of an involved circumferential resection margin in mucinous carcinoma versus adenocarcinoma patients (27.6% vs. 1.4%; P < 0.001). After multivariate regression analysis, mucinous carcinoma remained an independent prognostic factor for local recurrence (hazard ratio 3.6; 95% CI 1.1-12.4), although no differences in overall or disease-free survival were observed.

CONCLUSION

Mucinous rectal carcinoma is associated with a poor clinical response at restaging MRI after CRT, leading to relatively higher rates of involved circumferential resection margins at pathology. In this cohort, mucinous carcinoma seems to be a prognostic factor for increased risk of local recurrence, without an effect on overall survival.

External Validation of Pretreatment Pathological Tumor Extent in Patients with Neoadjuvant Chemoradiotherapy Plus Surgery for Esophageal Cancer

Background

This study was conducted to validate a pretreatment (i.e. prior to neoadjuvant chemoradiotherapy) pathological staging system in the resection specimen after neoadjuvant chemoradiotherapy for esophageal cancer. The study investigated the prognostic value of pretreatment pathological T and N categories (prepT and prepN categories) in both an independent and a combined patient cohort.

Methods

Patients with esophageal cancer treated with neoadjuvant chemotherapy and esophagectomy between 2012 and 2015 were included. PrepT and prepN categories were estimated based on the extent of tumor regression and regressional changes of lymph nodes in the resection specimen. The difference in Akaike’s information criterion (ΔAIC) was used to assess prognostic performance. PrepN and ypN categories were combined to determine the effect of nodal sterilization on prognosis. A multivariable Cox regression model was used to identify combined prepN and ypN categories as independent prognostic factors.

Results

The prognostic strength of the prepT category was better than the cT and ypT categories (ΔAIC 7.7 vs. 3.0 and 2.9, respectively), and the prognostic strength of the prepN category was better than the cN category and similar to the ypN category (ΔAIC 29.2 vs. − 1.0 and 27.9, respectively). PrepN + patients who became ypN0 had significantly worse survival than prepN0 patients (2-year overall survival 69% vs. 86% in 137 patients; p = 0.044). Similar results were found in a combined cohort of 317 patients (2-year overall survival 62% vs. 85%; p = 0.002). Combined prepN/ypN stage was independently associated with overall survival.

Conclusions

These results independently confirm the prognostic value of prepTNM staging. PrepTNM staging is of additional prognostic value to cTNM and ypTNM. PrepN0/ypN0 patients have a better survival than prepN +/ypN0 patients.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-08024-0) contains supplementary material, which is available to authorized users.

Prognostic Value of Pretreatment Pathological Tumor Extent in Patients Treated With Neoadjuvant Chemoradiotherapy Plus Surgery for Esophageal or Junctional Cancer

OBJECTIVE

We aimed to determine pretreatment pathological tumor extent in the resection specimen after neoadjuvant chemoradiotherapy (nCRT) and to assess its prognostic value in patients with esophageal cancer.

METHODS

Patients with esophageal cancer, treated with nCRT plus surgery were included (2003-2011). Pretreatment pathological T-stage (prepT-stage) and N-stage (prepN-stage) were estimated based on the extent of regressional changes and residual tumor cells in the resection specimen. Interobserver agreement was determined between 3 pathologists. The prognostic performance of prepT-stage and prepN-stage was scored using the difference in Akaike information criterion (ΔAIC). PrepN-stage and posttreatment pathological N-stage (ypN-stage) were combined to determine the effect of nodal sterilization on prognosis.

RESULTS

Overall concordance for prepT-stage and prepN-stage was 0.69 and 0.84, respectively. Prognostic strength of prepT-stage was similar to clinical T-stage and worse compared with ypT-stage (ΔAIC 1.3 versus 2.0 and 8.9, respectively). In contrast, prognostic strength of prepN-stage was better than cN-stage and similar to ypN-stage (ΔAIC 17.9 versus 6.2 and 17.2, respectively). PrepN+ patients who become ypN0 after nCRT have a worse survival compared with prepN0 patients, with a five year overall survival of 51% versus 68%, P = 0.019, respectively.

CONCLUSIONS

PrepT-stage and prepN-stage can be estimated reproducibly. Prognostic strength of prepT-stage is comparable with clinical T-stage, whereas prepN-stage is better than cN-stage. PrepN+ patients who become ypN0 after nCRT have a worse survival compared with prepN0 patients. Pretreatment pathological staging should be considered useful as a new staging parameter for esophageal cancer and could also be of interest for other tumor types.

Regression grading in neoadjuvant treated pancreatic cancer: an interobserver study

AIM

Several regression grading systems have been proposed for neoadjuvant chemoradiation-treated pancreatic ductal adenocarcinoma (PDAC). This study aimed to examine the utility, reproducibility and level of concordance of three most frequently used grading systems.

METHODS

Four gastrointestinal pathologists used the College of American Pathologists (CAP), Evans, MD Anderson Cancer Centre (MDA) regression grading systems to grade 14 selected cases (7-20 slides from each case) of neoadjuvant chemoradiation-treated PDAC. A postscoring discussion with each pathologist was conducted. The results were entered into a standardised data collection form and statistical analyses were performed.

RESULTS

There was little concordance across the three systems. The Kendall coefficient of concordance agreement scores were: CAP: 2-poor, 2-fair; Evans: 1-fair, 1-moderate, 2-good; MDA: 1-poor, 2-moderate, 1-good. Interpretation in all three grades in the CAP grading system was a source of discrepancy. Furthermore, using fibrosis as a criterion to assess regression was contentious. In the Evans system, quantifying tumour destruction using arbitrary percentage cut-offs (ie, 9% vs 10%; 50% vs 51%, etc) was imprecise and subjective. Although the MDA system generated greatest concordance, this was due to 'oversimplification' surrounding wide, arbitrarily assigned thresholds of </> 5% of tumour.

CONCLUSIONS

All systems lacked precision and clarity for accurate regression grading. Presently the clinical utility and impact of histological regression grading in patient management is questionable. There is a need to re-evaluate regression grading in the pancreas and establish a reproducible, clinically relevant grading system.

The spectrum of histopathological changes encountered in pancreatectomy specimens after neoadjuvant chemoradiation, including subtle and less-well-recognised changes

Preoperative (neoadjuvant) chemoradiation therapy/treatment (NCRT) is emerging as an important treatment modality in borderline resectable pancreatic ductal adenocarcinoma (PDAC). The constellation of histopathological changes secondary to chemoradiation is diverse and has been well documented, particularly in other gastrointestinal organs such as the oesophagus and colorectum. However, the histological changes specific to the pancreas have not been fully characterised and described. This review aims to provide a detailed catalogue of histological features associated with NCRT-treated PDAC and highlight any subtle, less-recognised changes.

Assessment of colloid response by nonlinear optical microscopy after preoperative radiochemotherapy for rectal carcinoma

Colloid response is a type of tumor response that occurs after preoperative radiochemotherapy for rectal carcinoma. Given its important influence on survival, the colloid response should be considered when estimating histopathological reactions. Here, multiphoton microscopy (MPM) was applied to evaluate the colloid response ex vivo. This study demonstrated that MPM has the capability to visualize the colloid response in the absence of labels and can, in particular, identify rare residual carcinomatous cells in mucin pools. These results highlight the potential of this nonlinear optical technique as a diagnostic tool for tumor response after neoadjuvant treatment.

Detection of morphologic alterations in rectal carcinoma following preoperative radiochemotherapy based on multiphoton microscopy imaging

BACKGROUND

Preoperative radiochemotherapy improves outcomes in patients with locally advanced rectal carcinoma, and has been used increasingly in patient management. However, there is a strong clinical need to assess tumor response to neoadjuvant treatment, and a non-invasive technique that allows the precise identification of morphologic changes in tumors would be of considerable clinical interest.

METHODS

In this study, we used multiphoton microscopy (MPM) to detect morphologic alterations in rectal adenocarcinomas in patients treated with preoperative radiochemotherapy.

RESULTS

MPM was able to identify histopathologic alterations in rectal cancer following preoperative radiochemotherapy, and allowed the qualitative assessment of treatment efficacy and feasibility in relation to dose or strategy.

CONCLUSION

These findings may provide the groundwork for evaluating tumor response to neoadjuvant treatment, thus allowing the tailoring of effective treatment doses and strategies.

Dynamic contrast-enhanced MRI: Use in predicting pathological complete response to neoadjuvant chemoradiation in locally advanced rectal cancer

PURPOSE

To determine the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) to predict pathological complete response (pCR) before preoperative chemoradiotherapy (CRT) in locally advanced rectal cancer.

MATERIALS AND METHODS

In a prospective clinical trial, 38 enrolled patients underwent pre- and post-CRT DCE-MRI at 3.0T. The tumor length and the following perfusion parameters (K(trans) , kep , ve ) were measured for the tumor and compared between the pCR group and the non-pCR group, as well as before and after CRT. For categorical variable comparison, the Kruskal-Wallis test was used. P < 0.05 was considered significant.

RESULTS

No difference in tumor length was found between the pCR and non-pCR group pre- and post-CRT (P = 0.26 (0.15,0.45), 0.35 (0.21,0.52), respectively). Before CRT, the mean tumor K(trans) in the pCR group was significantly higher than in the non-pCR group (P = 0.01). A K(trans) of 0.66 emerged as the best cutoff for distinguishing pCR from non-pCR. Regarding kep and ve , significant differences were also observed between the pCR and non-pCR groups (P = 0.02, 0.01, respectively). The mean K(trans) , kep , and ve values post-CRT were lower in the pCR group than in the non-pCR group, although there was no significant difference (P = 0.10 (0.04,0.16), 0.11 (0.07,0.26), 0.10 (0.06,0.23), respectively).

CONCLUSION

Before neoadjuvant chemoradiotherapy in rectal cancer, DCE-MRI can distinguish between complete and incomplete response using a K(trans) threshold of 0.66 with a sensitivity of 100%.

Perfusion MRI for the prediction of treatment response after preoperative chemoradiotherapy in locally advanced rectal cancer

OBJECTIVES

To evaluate the utility of perfusion MRI as a potential biomarker for predicting response to chemoradiotherapy (CRT) in locally advanced rectal cancer.

METHODS

Thirty-nine patients with primary rectal carcinoma who were scheduled for preoperative CRT were prospectively recruited. Perfusion MRI was performed with a 3.0-T MRI system in all patients before therapy, at the end of the 2nd week of therapy, and before surgery. The K (trans) (volume transfer constant) and V (e) (extracellular extravascular space fraction) were calculated.

RESULTS

Before CRT, the mean tumour K (trans) in the downstaged group was significantly higher than that in the non-downstaged group (P = 0.0178), but there was no significant difference between tumour regression grade (TRG) responders and TRG non-responders (P = 0.1392). Repeated-measures analysis of variance (ANOVA) showed significant differences for evolution of K (trans) values both between downstaged and non-downstaged groups (P = 0.0215) and between TRG responders and TRG non-responders (P = 0.0001). Regarding V (e), no significant differences were observed both between downstaged and non-downstaged groups (P = 0.689) or between TRG responders and TRG non-responders (P = 0.887).

CONCLUSION

Perfusion MRI of rectal cancer can be useful for assessing tumoural K (trans) changes by CRT. Tumours with high pre-CRT K (trans) values tended to respond favourably to CRT, particularly in terms of downstaging criteria.

KEY POINTS

• Perfusion MRI can now assess therapeutic response of tumours to therapy. • Tumours with high initial K ( trans ) values responded favourably to chemoradiotherapy. • Perfusion MRI of rectal cancer may help with decisions about management.

The role of the pathologist in rectal cancer diagnosis and staging and surgical quality assessment

Since the introduction of the total mesorectal excision by Heald, many changes in the therapeutic management of rectal cancer have been incorporated. The multidisciplinary approach to colorectal cancer, integrated in a team of different specialists, ensures individualised treatment for each patient with rectal cancer. Therefore the role of the pathologist has acquired an important relevance, not only in diagnosing but also managing and evaluating the surgical specimen. The knowledge of preoperative staging, distance between tumour and anal verge or in patients subjected to a neoadjuvant treatment is necessary for the pathologist to make a detailed, accurate and good-quality report. Parameters such as the macroscopic quality of the mesorectum, the status of the circumferential resection margin and the lymph node harvest are considered basic criteria recommended by the current guidelines for the multidisciplinary team audit.

CD133 expression in rectal cancer after preoperative chemoradiotherapy

CD133-positive cells have been reported to possess a cancer-initiating-cell phenotype and the property of resistance to chemoradiation therapy in colorectal cancer. The aim of the present study was to evaluate quantitative and locational changes in CD133-positive cells in rectal cancer patients who received preoperative chemoradiation therapy. The prognostic significance of CD133 expression in patients with preoperative chemoradiation therapy was also analyzed. Immunohistochemical staining for CD133 and cancer-initiating-cell marker CD44 were performed in 92 surgically resected rectal cancers. Of the 92 cases, 43 patients received preoperative chemoradiation therapy and 49 patients underwent surgery alone. Forty pretherapic biopsy specimens from 43 patients in preoperative chemoradiation therapy group were also analyzed. CD133-positive cases were more common in the preoperative chemoradiation therapy group than in the surgery-alone group (P = 0.03). Further, CD133-positive cases were more common in the preoperative chemoradiation therapy group than in pretherapic biopsy specimens (P = 0.02). In the preoperative chemoradiation therapy group, the CD133-positive cases showed poorer prognosis than the CD133-negative cases. On the other hand, the frequency of CD44-positive case within cancer tissue was similar between the preoperative chemoradiation therapy group and the surgery-alone group. CD44 expression in the preoperative chemoradiation therapy group was not associated with prognosis. CD44- and CD133-positive cells were distributed evenly within the tumor both in the preoperative chemoradiation therapy group and surgery-alone group, and locational alteration was not observed. The therapy-resistant ability of CD133-positive cells can be associated with poor outcome in the patients with preoperative chemoradiation therapy.

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.

The number of lymph nodes is correlated with mesorectal morphometry

BACKGROUND

Lymph node involvement is one of the most significant prognostic factors of patients with rectal cancer. However, the distribution of mesorectal lymph nodes is not well known. This study was designed to assess lymph nodes in the mesorectum and to evaluate the correlation between the volume and weight of the mesorectum and the number of lymph nodes.

METHODS

The mesorectums of 20 human cadavers were studied. The volume and weight of the superior rectal mesentery, superior mesorectum and inferior mesorectum were measured. Lymph nodes were sought by manual dissection and were submitted for histological examination. The correlation between the number of lymph nodes and the volume and weight of the mesorectum was evaluated by non-parametric Spearman test.

RESULTS

A total of 178 lymph nodes were identified. The mean number of lymph nodes per specimen was 9.2 +/- 4.5. The lymph nodes were mostly smaller than 3 mm and located in the superior and posterior parts of the mesorectum. A positive correlation was found between the number of mesorectal lymph nodes and the volume and weight of the mesorectum. The number of lymph nodes in the superior rectal mesentery was independent of its volume and its weight.

CONCLUSIONS

Mesorectal lymph nodes are mainly located above the peritoneal reflection within the posterior mesorectum. The positive correlation between the volume or the weight of the mesorectum and the number of mesorectal lymph nodes should be considered as a possible means to determine the minimum number of mesorectal lymph nodes required for histological examination.

Mucosal endocrine cell micronests and single endocrine cells following neo-adjuvant therapy for adenocarcinoma of the distal oesophagus and oesophagogastric junction

AIMS

To determine the frequency of endocrine cell micronests (ECM) and single endocrine cells (SEC) within the glandular mucosa of the distal oesophagus and oesophagogastric junction (OGJ) following neo-adjuvant therapy for adenocarcinoma.

METHODS

The resection specimens from 11 patients with adenocarcinoma of the distal oesophagus or OGJ who had undergone preoperative chemotherapy or chemoradiotherapy (CRT) were reviewed and stained immunohistochemically for cytokeratin and chromogranin. The presence of ECM and/or SEC within the mucosa adjacent to the tumour was noted, and the results correlated with the extent of tumour regression. The corresponding pretreatment endoscopic biopsy specimens were reviewed in 6 cases, and the results were also compared to 10 tumour resections from patients with no history of neo-adjuvant treatment.

RESULTS

ECM and/or SEC were identified in 8/11 resection specimens after chemotherapy or CRT. The endocrine cells were typically located within the deep lamina propria or muscularis mucosae and were associated with varying degrees of glandular atrophy and inflammation. The appearances were most consistent with endocrine cell preservation (pseudo-hyperplasia) following treatment. Isolated endocrine elements were not seen in the pretreatment biopsy specimens, while rare SEC without ECM were identified in only 2/10 control resection specimens.

CONCLUSIONS

Endocrine cell pseudo-hyperplasia may be seen within atrophic glandular mucosa following neo-adjuvant therapy of distal oesophageal/OGJ adenocarcinomas. The changes are analogous to those seen in chronic atrophic gastritis and should not be misinterpreted as those of residual tumour.

Recommendations for the reporting of surgically resected specimens of colorectal carcinoma

The reporting of colorectal cancer is facilitated by the provision of a checklist giving the features required for good patient care. However, the practicalities of applying such a checklist may not be straightforward. Familiar examples include finding the prescribed number of lymph nodes, distinguishing mesenteric tumor deposits from replaced lymph nodes, and deciding if a cluster of malignant cells in a lymph node sinus counts as metastasis. Checklists have traditionally focused on prognostic factors and, particularly, tumor stage. It is becoming increasingly clear that additional factors, whether morphological or molecular, will be needed for future clinical management. It is also evident that prognosis is strongly influenced by the surgical technique used, most notably by the introduction of total mesorectal excision in the case of rectal cancer. Adjuvant therapy is playing an increasingly important role in the management of colorectal cancer, and it is inevitable that morphological and molecular markers will be used to predict responses to the expanding range of therapeutic modalities. Neoadjuvant or preoperative radiotherapy is being offered to patients with advanced rectal cancer and can greatly modify the pathologic findings in operative specimens. For all the preceding reasons, the work of diagnostic pathologists has become increasingly complex and demanding. The 6th edition of the TNM classification fails to meet many of the challenges posed by the realities of modern cancer management. In fact, by changing the rules for staging without strong justification and introducing diagnostic criteria that are unhelpful and lack a good evidence base, there is a real danger that the community of pathologists will fail to engage with reporting recommendations in a standardized manner and that the quality of reporting will decline.

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

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

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

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

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

Disseminated tumor cells in peripheral blood: a novel marker for therapy response in locally advanced rectal cancer patients undergoing preoperative chemoradiation

PURPOSE

This study was designed to examine whether disseminated tumor cells in peripheral blood of locally advanced rectal cancer patients undergoing preoperative chemoradiation have the potential to serve as a marker for therapy response. Studies suggest that patients with advanced rectal cancer who respond to preoperative chemoradiation most likely benefit from this treatment.

METHODS

From advanced rectal cancer patients undergoing preoperative chemoradiation, peripheral blood was obtained at defined times: before, during, and after chemoradiation and during surgery. Patients were divided into histopathologic responders (ypT0-T2) and nonresponders (ypT3-T4). Cytokeratin 20 and carcinoembryonic antigen reverse transcriptase-polymerase chain reaction were performed to detect disseminated tumor cells. A blood sample was deemed positive for disseminated tumor cells if both carcinoembryonic antigen and cytokeratin 20 were detected.

RESULTS

The overall population (n = 26) showed a positivity rate of 32 percent for disseminated tumor cells before initiation of chemoradiation. Of the responders (n = 8), 63 percent were positive for disseminated tumor cells before chemoradiation, whereas only 18 percent of nonresponders (n = 18) were positive (P = 0.026). From initiation of chemoradiation to the end of surgery, a significant decrease was seen in tumor cell positivity in the blood of responders (P = 0.042). Moreover, the responders represented a trend toward a decrease in tumor cell positivity during chemoradiation (P = 0.079). In contrast, there were no noticeable alterations within the treatment course in nonresponders.

CONCLUSIONS

This prospective proof of principle study demonstrates that locally advanced rectal cancer with preoperative chemoradiation shows different biologic behavior in terms of tumor cell dissemination in peripheral blood when therapy responders compared with nonresponders.

Effects of radiotherapy on different histopathological types of rectal carcinoma

BACKGROUND

Down staging by pre-operative chemoradiotherapy is currently considered part of the standard therapeutic approach to rectal carcinoma. The aim of this study was to assess the response to chemoradiotherapy of different histopathological types of rectal carcinoma with emphasis on the mucinous variant.

METHOD

Between 1997 and 2002, 71 patients who received pre-operative chemoradiotherapy followed by surgery for rectal carcinoma were enrolled in the study. Staging of the rectal carcinoma was performed according to transrectal ultrasound findings (TN score) prior to the chemoradiotherapy. The chemoradiotherapy was followed by radical resection with mesorectal excision. All surgical specimens were examined by a single pathologist (MB). Pathological TN staging was assessed and tumour regression was graded according to a standard method (TRG1, complete response - TRG5 no response). Tumours were classified as mucinous or nonmucinous according to pre- and post-operative biopsy and specimen histopathological types. TN score change and TRG differences between groups were assessed.

RESULTS

Tumour regression was seen after chemoradiotherapy in 94.4% of the patients, while in 5.6% of the patients no response was found. The change in TN score and TRG were correlated. Higher TRG was associated with a smaller decrease in TN staging. TRG was significantly lower in the nonmucinous compared to the mucinous group and the decrease in TN grade was significantly larger in the nonmucinous group.

CONCLUSION

Mucinous carcinoma was associated with a lower response to pre-operative chemo-radiotherapy in this group of rectal carcinoma patients. Further studies are needed to determine its prognostic value.

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.

The radiation-induced changes in rectal mucosa: Hyperfractionated vs. hypofractionated preoperative radiation for rectal cancer

PURPOSE

The purpose of the study was the qualitative and quantitative evaluation of acute radiation-induced rectal changes in patients who underwent preoperative radiotherapy according to two different irradiation protocols.

PATIENTS AND METHODS

Sixty-eight patients with rectal adenocarcinoma underwent preoperative radiotherapy; 44 and 24 patients underwent hyperfractionated and hypofractionated protocol, respectively. Fifteen patients treated with surgery alone served as a control group. Five basic histopathologic features (meganucleosis, inflammatory infiltrations, eosinophils, mucus secretion, and erosions) and two additional features (mitotic figures and architectural glandular abnormalities) of radiation-induced changes were qualified and quantified.

RESULTS

Acute radiation-induced reactions were found in 66 patients. The most common were eosinophilic and plasma-cell inflammatory infiltrations (65 patients), erosions, and decreased mucus secretion (54 patients). Meganucleosis and mitotic figures were more common in patients who underwent hyperfractionated radiotherapy. The least common were the glandular architectural distortions, especially in patients treated with hypofractionated radiotherapy. Statistically significant differences in morphologic parameters studied between groups treated with different irradiation protocols were found.

CONCLUSION

The system of assessment is a valuable tool in the evaluation of radiation-induced changes in the rectal mucosa. A greater intensity of regenerative changes was found in patients treated with hyperfractionated radiotherapy.

Rectal adenocarcinoma with oncocytic features: possible relationship with preoperative chemoradiotherapy

BACKGROUND

The introduction of preoperative chemoradiation into the treatment protocol of rectal adenocarcinomas has affected the microscopical morphology in subsequent resection specimens. The constellation of histopathological changes is varied and well documented.

AIM

To describe oncocytic change in rectal cancers that have been treated with chemoradiation before surgery.

METHODS

7 of 54 patients with rectal cancer were identified with a history of chemoradiation, specifically directed to the rectal tumours in fractions of 4500-5000 cGy of radiation and 5-fluorouracil. The rectal tumours in five of these seven patients were composed of oncocytes that constituted 30-80% of the cancers. The patients were three men and two women aged 65-73 years, all with T3 N0 tumours. The intervals between chemoradiation and resection varied from 3 to 12 weeks.

RESULTS

The tumour cells conformed to oncocytes morphologically (large size with abundant, granular eosinophilic cytoplasm, vesicular nuclei and prominent acidophilic nucleoli), immunohistochemically (positive for carcinoembryonic antigen, cytokeratin 20 and caudal type homeo box transcription factor 2, but negative for both chromogranin and synaptophysin) and ultrastructurally (large cells showing tight junctions, cytoplasmic engorgement by mitochondria and absence of neurosecretory granules).

CONCLUSIONS

The changes in these cells differ from those described previously in endocrine cells encountered in pretreated rectal cancers. Oncocytic change in this particular clinical context occurs as a reflection of cytotoxic damage or cellular hypoxia induced by chemoradiation resulting in degeneration of the cell and the oncocytic phenotype. Oncocytic change may be an under-recognised histopathological change in rectal cancers receiving preoperative chemoradiation.

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.

Pathological response following long-course neoadjuvant chemoradiotherapy for locally advanced rectal cancer

AIMS

To standardize the pathological analysis of total mesorectal excision specimens of rectal cancer following neoadjuvant chemoradiotherapy for locally advanced disease (T3/T4), including tumour regression.

METHODS AND RESULTS

Standardized dissection and reporting was used for 60 patients who underwent total mesorectal excision following long-course chemoradiotherapy. Tumour regression was scored by two pathologists (K.S., D.G.) using both an established 5-point tumour regression grade (TRG), and a novel 3-point grade. Both scores were evaluated for interobserver variability. A complete or near-complete pathological response (3-point TRG 1) was found in 10 patients (17%). Using the 5-point TRG, there was good agreement between both pathologists (kappa = 0.64). Using the 3-point grade, agreement was excellent (kappa = 0.84). No disease recurrence has been reported in patients with a complete, or near complete pathological response (3-point TRG 1), after a mean follow-up of 22 months.

CONCLUSION

Tumour regression grade is a useful method of scoring tumour response to chemoradiotherapy in rectal cancer. TRG 1 and 2 can be regarded as a complete pathological response (ypT0). A modified 3-point grade has the advantage of better reproducibility, with similar prognostic significance.

Tumour regression grading in the evaluation of tumour response after different preoperative radiotherapy treatments for rectal carcinoma

BACKGROUND AND AIMS

Preoperative radiotherapy (PRT) for rectal carcinoma has been shown to cause tumour regression and increase local control and patient survival. The aim of this study was to examine the usefulness of tumour regression grading (TRG) in quantifying the effect of PRT.

METHODS

Depending on the tumour stage (uT), as defined by preoperative endorectal ultrasound (ERUS), fixity and distance from the anal verge, 126 patients with rectal cancer underwent either surgery alone, or received short-course 25-Gy radiotherapy or long-course 50-Gy radiotherapy combined with 5-fluorouracil (5-FU) before surgery. TRG in each group was assessed and compared with the downstaging, defined as a change in preoperative uT stage and pathologic stage (pT).

RESULTS

Complete response (no residual tumour, TRG 1) was seen in 7% of the patients (3/44) and total or major regression (TRG 1-3) in 73% of the patients (32/44) treated with 50-Gy chemoradiation. Of those treated with 25-Gy PRT, 21% (9/42) showed major tumour regression. Of the patients who underwent ERUS and PRT, 32% (26/83) were downstaged when comparing uT with pT, but 53% (14/26) of the downstaged tumours showed no response by TRG. In comparison, 50% (28/57) of the tumours with no downstaging showed a marked response by TRG (p=0.05).

CONCLUSIONS

Tumour regression grading offers detailed information of the effect of PRT and shows that tumour regression is more marked after long-term chemoradiation than after short-course radiotherapy (p=0.02). In contrast, T-stage downstaging was similar in both groups and did not correlate with the TRG results (p=0.05).

The effect of preoperative radiotherapy on systemic collagen deposition and postoperative infective complications in rectal cancer patients

PURPOSE

Preoperative, high-dose radiotherapy for rectal cancer reduces local recurrence rates and improves overall survival. However, adverse effects in varying degrees include impaired wound healing and local infection. This study investigates the influence of preoperative, high-dose radiotherapy on subcutaneous accumulation of collagen in a primary rectal cancer group operated on with or without adjuvant radiotherapy.

METHODS

Forty-two eligible patients who underwent total mesorectal excision surgery with or without radiotherapy were included in the study. Polytetrafluoroethylene tubings were implanted in the arm ten days before surgery (three days before the start of radiotherapy). Implants were extracted the day before surgery. New implants were inserted before surgery and were extracted ten days after surgery. The hydroxyproline and proline contents of the implants were measured and the hydroxyproline/proline ratio was calculated as a measure for deposited collagen relative to protein. Blood loss, postoperative complications, and blood levels of hemoglobin, leukocytes, and albumin were recorded.

RESULTS

The two groups were similar in relation to Dukes stage, age, and body mass index. Infectious complications developed in 39 percent of patients after radiotherapy compared with 16 percent in the nonirradiated group. In the irradiated patients with infective complications we found a significant decrease in the hydroxyproline/proline ratio compared with that of irradiated patients without infections (P = 0.037). There was a significant decrease in the leukocyte count preoperatively and postoperatively in the irradiated group compared with surgery alone.

CONCLUSIONS

High-dose, short-term radiotherapy does not have a systemic effect on collagen accumulation, but a significant reduction is manifested in infected patients. Radiotherapy also impairs leukocyte production and increases the postoperative infective complication rate.

Impact of colloid response on survival after preoperative radiotherapy in locally advanced rectal carcinoma

Neoadjuvant therapy for rectal carcinoma modifies morphology and natural history of the tumor. Colloid response defined by predominant colloid changes with or without residual tumor cells is a form of tumor response whose impact on survival is unknown. This study evaluated influence of tumor histologic response, especially of colloid response, on survival in patients treated by long-course preoperative radiotherapy for rectal cancer. In 200 patients with uT3-T4 or N1 rectal carcinomas, influence of type of surgery, dose of radiotherapy, residual tumor size, surface tumor aspect, tumor response (downstaging vs. colloid or no response), tumor grade, vascular and neural invasion, circumferential margin, and postoperative chemotherapy on 5-year overall and disease-free survival were studied by univariate and multivariate analyses. A colloid response was observed in 20% of the cases. Tumor response, circumferential margin, and vascular invasion were independently associated with the disease-free survival. Patients with downstaging had a better disease-free survival than patients without response (80% vs. 54%), whereas those with colloid response had an intermediate survival (64%). After colloid response, the rate of recurrence was similar to patients with downstaging for local recurrence (0%-3%) and to those with no response for distant recurrence (28%). After preoperative radiotherapy for rectal cancer, survival and type of recurrence are influenced by the tumor response. The intermediate natural history of patients with colloid response suggests taking colloid response into account in postoperative tumor staging to optimize adjuvant therapy.

Radiation enteropathy and leucocyte-endothelial cell reactions in a refined small bowel model

BACKGROUND

Leucocyte recruitment and inflammation are key features of high dose radiation-induced tissue injury. The inflammatory response in the gut may be more pronounced following radiotherapy due to its high bacterial load in comparison to the response in other organs. We designed a model to enable us to study the effects of radiation on leucocyte-endothelium interactions and on intestinal microflora in the murine ileum. This model enables us to study specifically the local effects of radiation therapy.

METHOD

A midline laparotomy was performed in male C57/Bl6 mice and a five-centimetre segment of ileum is irradiated using the chamber. Leucocyte responses (rolling and adhesion) were then analysed in ileal venules 2 - 48 hours after high dose irradiation, made possible by an inverted approach using intravital fluorescence microscopy. Furthermore, intestinal microflora, myeloperoxidase (MPO) and cell histology were analysed.

RESULTS

The highest and most reproducible increase in leucocyte rolling was exhibited 2 hours after high dose irradiation whereas leucocyte adhesion was greatest after 16 hours. Radiation reduced the intestinal microflora count compared to sham animals with a significant decrease in the aerobic count after 2 hours of radiation. Further, the total aerobic counts, Enterobacteriaceae and Lactobacillus decreased significantly after 16 hours. In the radiation groups, the bacterial count showed a progressive increase from 2 to 24 hours after radiation.

CONCLUSION

This study presents a refinement of a previous method of examining mechanisms of radiation enteropathy, and a new approach at investigating radiation induced leucocyte responses in the ileal microcirculation. Radiation induced maximum leucocyte rolling at 2 hours and adhesion peaked at 16 hours. It also reduces the microflora count, which then starts to increase steadily afterwards. This model may be instrumental in developing strategies against pathological recruitment of leucocytes and changes in intestinal microflora in the small bowel after radiotherapy.

Decreased detection rate of disseminated tumor cells of rectal cancer patients after preoperative chemoradiation: a first step towards a molecular surrogate marker for neoadjuvant treatment in colorectal cancer

OBJECTIVE

To compare the detection rates for rectal cancer cells in blood and bone marrow in patients with or without preoperative chemoradiation.

SUMMARY BACKGROUND DATA

Previous reports have postulated a resistance of disseminated tumor cells to antiproliferative agents because of tumor cell dormancy.

METHODS

Blood samples from 142 patients (pre, intra-, and postoperative samples) and bone marrow samples from 127 patients undergoing resection of rectal adenocarcinoma were analyzed for tumor cells using a cytokeratin (CK) 20-reverse transcription polymerase chain reaction. The results were stratified according to preoperative therapy.

RESULTS

In patients without preoperative chemoradiation, tumor cell detection in blood and bone marrow correlated to tumor stage (Cochran Armitage trend test, P < 0.05). Tumor cells were detected in 34 of 103 (33%) bone marrow and 65 of 117 (55.6%) blood samples of patients without neoadjuvant treatment versus in 4 of 24 (16.7%) bone marrow and in 10 of 25 (40%) blood samples of patients with neoadjuvant treatment. The tumor cell detection rate was significantly lower in the group having undergone chemoradiation (binary logistic regression analysis, P < 0.05). The overall and disease-free survival were significantly worse in patients with tumor cell detection in the bone marrow after neoadjuvant therapy.

CONCLUSIONS

Preoperative chemoradiation is associated with a decreased detection rate of rectal cancer cells in blood and bone marrow. These findings may explain the observed clinical benefit of patients with rectal cancer receiving chemoradiation. This is the first study suggesting that detection of disseminated rectal cancer cells may be useful for assessing the efficacy of neoadjuvant therapy.

Effect of neoadjuvant chemoradiotherapy on angiogenesis in oesophageal cancer

Background

Vascular endothelial growth factor (VEGF) levels are raised in the serum of patients with oesophageal carcinoma. The aim of this study was to evaluate the tumour microvasculature and the role of tumour-associated macrophages in VEGF production after neoadjuvant chemoradiotherapy and surgery for oesophageal cancer.

Methods

Sections from 92 consecutively resected oesophageal tumours were stained for VEGF, von Willebrand factor and CD68. Twenty-seven patients received preoperative chemoradiation and 65 underwent surgical excision alone. The cellular source of VEGF was determined by parallel-section staining. Microvessel density and macrophage count were determined for each tumour by means of image analysis software.

Results

There were no significant differences between the two groups in age, sex or tumour type. Local downstaging of disease was evident in most specimens of tumours that had received preoperative chemoradiation. All tumours stained positive for VEGF, including those demonstrating a complete pathological response. Staining of parallel sections confirmed macrophages as the principal source of VEGF. Mean microvessel density was 6·4 per high-power field (h.p.f.) in tumours that received preoperative chemoradiation compared with 5·3 per h.p.f. in those treated by surgery alone (P = 0·130). A significant increase in tumour-associated macrophage infiltration was noted in tumours treated with neoadjuvant chemoradiation (22·1 per h.p.f.) compared with those treated by surgery alone (14·3 per h.p.f.) (P = 0·042).

Conclusion

Preoperative chemoradiation had little effect on the local angiogenic profile of the tumour in patients with oesophageal cancer. Tumour-infiltrating macrophages seem to be the source of persistent VEGF production after chemoradiotherapy and might explain the raised serum levels. Addition of an antiangiogenic agent to this regimen may be worthwhile in patients with oesophageal carcinoma.

Modern management of colorectal cancer--a pathologist's view

Colorectal cancer is an increasingly significant cause of both mortality and morbidity due to wider adoption of the Western lifestyle and a progressively ageing population. Recently steps forward have been made both in surgical and chemoradiotherapeutic management of this disease. Well performed total mesorectal excision surgery has now become the gold standard for rectal cancer resection. Several prognostic markers, both clinicopathological and molecular, have been identified allowing better patient counselling and targeting of treatment. The rationale for patient selection, timing and dose of radiotherapy has been further elucidated. New chemotherapy agents are under trial and predictive factors allowing selection of those patients most likely to respond to them have been identified. Many of these factors will increase in importance as colorectal cancer becomes a chronic disease with lengthening survival times. As we will discuss the pathologist has important roles in all of these developments and at all stages of colorectal cancer management.

Preoperatively irradiated rectal carcinoma: analysis of the histopathologic response and predictive value of proliferating cell nuclear antigen immunostaining

OBJECTIVES

To investigate the relationship between the histopathologic effects of preoperative chemoradiotherapy in rectal cancer and the proteins, proliferating cell nuclear antigen (PCNA) and p53.

METHODS

Samples from 73 tumors were examined. The histopathologic effects observed in the resected specimens induced by preoperative chemoradiotherapy were correlated with the inmunohistochemical expression of PCNA and p53 in biopsies obtained by rectoscopy before chemoradiotherapy.

RESULTS

Thirty-five tumors showed a high PCNA index (48%). Nuclear accumulation of p53 protein was detected in 53 tumors (72%). Specimens were assigned one of four grades based on the amount of residual viable tumor. Three neoplasms (4%) showed complete regression; 8 other carcinomas (11%) showed only small numbers of tumor cells scattered within the field of stromal reaction. In these cases, it was considered that the tumor had responded significantly to radiotherapy. Tumors with a high PCNA index responded to chemoradiotherapy more frequently (8/35; 72%) than tumors with a low index (3/38; 43%) (p = 0.07). p53-negative tumors responded more frequently (4/20; 20%) than positive tumors (7/53; 13.2%) (p = 0.50). When pathologic and immunohistochemical characteristics of the tumors were included in a logistic regression model, only high PCNA index (odds ratio 5.35, 95% confidence interval 1.07-26.7) (p = 0.04) was significantly associated with the histologic response to preoperative chemoradiotherapy.

CONCLUSION

High proliferative activity of rectal cancer, as determined by PCNA immunostaining, is predictive of the response to preoperative chemoradiotherapy.

Importance of tumor regression assessment in predicting the outcome in patients with locally advanced rectal carcinoma who are treated with preoperative radiotherapy

BACKGROUND

Locally advanced rectal carcinoma has a poor prognosis. However, since the introduction of preoperative radiotherapy, the outcome of patients with rectal carcinoma has been reported to have improved. Nevertheless, to the authors' knowledge few data are available regarding the histopathologic response to radiotherapy as assessed on surgical specimens as a potential predictive factor for outcome.

METHODS

To estimate the effect of radiotherapy on rectal carcinoma, the authors retrospectively reviewed the surgical specimens of 102 patients with T3-4, N0 or > or = N1 rectal carcinoma and 1 patient with T2 but N1 rectal carcinoma. All patients were treated preoperatively with a hyperfractionated accelerated radiotherapy schedule in a prospective protocol (Trial 93-01). Using a standardized approach, tumor regression was graded using a system that varies from Grade 1 (tumor regression Grade [TRG] 1) when complete tumor regression is observed to Grade 5 (TRG5) when no tumor regression is observed.

RESULTS

Radiotherapy resulted in tumor downstaging in 43% of the patients. There were 2 pT1 tumors (2%), 21 pT2 tumors (20%), 66 pT3 tumors (64%), and 14 pT4 tumors (14%) after treatment. Regional lymph nodes were involved in 55 patients (53%). None of the patients demonstrated a complete tumor regression after radiotherapy, but in 79% of the specimens a partial tumor regression was observed (TRG1: 0%; TRG2: 20%; TRG3: 39%; TRG4: 20%; and TRG5: 21%). The median actuarial overall survival (OS) and disease-free survival (DFS) were 52 months. Actuarial local recurrence rates at 2 years and 5 years were 6.4% and 7.6%, respectively. Univariate analysis showed the actuarial DFS to be significantly lower in patients with lymph node metastases (P = 0.0004) and advanced pT stages (pT3-4) (P = 0.03). A favorable outcome for OS, DFS, and local control was observed in patients with TRG2-4 (i.e., responders) compared with patients with TRG5 (i.e., nonresponders), but also in patients with low residual tumor cell density (TRG2, 3, and 4). On multivariate analysis, TRG remained an independent prognostic indicator for local tumor control.

CONCLUSIONS

Tumor regression as well as residual tumor cell density were found to be predictive factors of survival in rectal carcinoma patients after preoperative radiotherapy. Even after preoperative radiotherapy, the pathologic stage of the surgical specimen remained a prognostic factor. The use of a standardized approach for pathologic evaluation must be implemented to allow comparison between the results of various treatment approaches.

[Radiation-induced esophageal carcinoma: report of 11 cases]

STUDY AIM

Radiation-induced oesophageal carcinoma can occur several years after mediastinal irradiation. The aim of this study was to report 11 cases of this rare entity with analysis of its diagnostic, therapeutic and prognostic special features.

PATIENTS AND METHODS

From 1983 to 2001, 10 female and one male patients, aged 47 to 76 years, were treated for an oesophageal squamous cell carcinoma which was diagnosed 5 to 25 years after mediastinal irradiation. This irradiation (30 to 78 Gy) was administered in 8 women for breast carcinoma and in other patients for lymphoma. Only one patient had alcoholic consumption and 2 were smokers. An oesophagectomy was performed whenever possible.

RESULTS

All (but one) oesophageal tumors were symptomatic. Ten patients underwent an oesophagectomy, including 2 without thoracotomy. Postoperative course was uneventful in 6 cases, 3 patients developed transient respiratory failure and one patient died postoperatively. At late follow-up, 6 patients developed distant metastases (mainly hepatic and pulmonary). These metastases were associated with mediastinal recurrences in 2 cases. No isolated mediastinal recurrence occurred. Median survival was 13 months.

CONCLUSION

Clinical presentation and surgical treatment of radiation-induced oesophageal carcinoma are similar to those of other oesophageal squamous cell carcinomas. After oesophagectomy, isolated mediastinal recurrences seem to be rarer than with other cancers. These cancers, which are almost all symptomatic, have a poor prognosis.

Acute radiation colitis in patients treated with short-term preoperative radiotherapy for rectal cancer

The histopathologic features of acute radiation-induced colitis in humans have been described in occasional, >20-year-old studies, but they have not been analyzed in detail. We characterize such findings in 34 patients with rectal cancer who underwent surgery a few days after preoperative irradiation with 25 Gy given over 5-7 days, and we compare the results to the histopathologic features detected in 18 patients treated by a conventional preoperative irradiation protocol consisting of 45 Gy during 5 weeks followed by surgery after a time interval of at least 3 weeks. Short-term preoperative irradiation therapy generally induced severe mucosal inflammation characterized by increased cellularity of the lamina propria, prominent eosinophilic infiltrates, crypt disarray, surface and crypt epithelial damage, nuclear abnormalities, and presence of apoptotic bodies in the crypt epithelium. These histopathologic features were absent or detected only occasionally in the patient group treated according to the long-term preoperative irradiation protocol. Despite acute severe inflammation, none of the patients treated by short-term irradiation developed perioperative complications. These observations indicate that acute radiation colitis may remain clinically silent and resolve spontaneously within a few weeks after irradiation. Given the widening acceptance of short-term preoperative irradiation protocols for rectal cancer, pathologists should be aware of the rather characteristic histologic findings of acute radiation colitis and avoid unnecessary concern of clinicians. The differential diagnosis includes infectious colitis, collagenous and ischemic colitis, nonsteroidal anti-inflammatory drug-associated colitis, and chronic idiopathic inflammatory bowel disease.

Local recurrence after mesorectal excision for rectal cancer

AIMS

Controversy still exists about the optimal surgical treatment of rectal cancer. The main purpose of the present study was to compare local recurrence (LR) rates after mesorectal excision (ME) and conventional surgery (CS) technique.

METHODS

All rectal cancer patients from a defined catchment area were included. Outcome after ME in the period 1993-1999 (n=161) was compared with the outcome after CS (n=217) in the period 1983-1992. Partial ME (PME) was the routine in upper, and total ME the routine in mid- and low rectal cancer. The follow-up programmes were identical, and the median observation times very similar (37 and 38 months) in the two periods. Five-year actuarial LR rate and survival were estimated using the Kaplan-Meier method, and adjustment for prognostic factors was performed with Cox regression analysis.

RESULTS

Total LR rate after R0 resection was 7.7% crude and 9% 5 year actuarial in the ME period, as compared with 16.0% crude and 24% actuarial in the CS period (P=0.02). Cox regression analyses confirmed these differences with a hazard ratio of 0.40 for ME vs CS (P=0.02). Isolated LR rate was 2% after ME and 8% after CS. Five-year actuarial total LR rate after rectal resection with curative intent was 11% after ME and 27% after CS (P<0.01). Actuarial total LR rate after PME was 6%, and none of these patients developed isolated LR.

CONCLUSION

Standardization of surgical technique and application of ME resulted in a significant reduction of LRs. LR rate was low after PME, indicating that this procedure is adequate in upper rectal cancer.

Anatomic study of the lymph nodes of the mesorectum

PURPOSE

Lymph node involvement is the most important prognostic factor when staging patients with colorectal cancer. The probability of detecting metastasis grows with the number of nodes examined. However, the number of nodes found in surgical specimens varies substantially. We have therefore determined the number and distribution of lymph nodes in the mesorectum by cadaveric dissection.

METHODS

Twenty formalin-fixed cadaveric pelvises were dissected (13 males). The search for lymph nodes was performed in a systematic way, from the division of the superior rectal artery following the smallest visible branches to the level of the anorectal ring.

RESULTS

A total of 168 lymph nodes were found in 20 mesorectal blocks, with a mean (standard deviation) number per specimen of 8.4 (4.45). Lymph node size ranged from 2 to 10 mm. Distribution of lymph nodes in mesorectum was as follows: 120 nodes (71.4 percent) were found around the branches of the superior rectal artery proximal to the peritoneal reflection, and 48 nodes (28.6 percent) were found distal to the peritoneal reflection. Fourteen specimens (70 percent) had lymph nodes at the division of the superior rectal artery.

CONCLUSIONS

The mean number of lymph nodes found in the mesorectum distal to the superior rectal artery division was 8.4. Most of these lymph nodes were proximal to the peritoneal reflection. The range found in the number of lymph nodes per case should be considered for use in the formulation of guidelines in anatomicopathologic studies of surgical specimens obtained after mesorectal excision.

Phase II clinical trial of preoperative combined chemoradiation for T3 and T4 resectable rectal cancer: preliminary results

PURPOSE

Although preoperative chemoradiation for high-risk rectal cancer may improve survival and local recurrence rate, its adverse effects are not well defined. This prospective study evaluated the use of preoperative chemoradiation for T3 and T4 resectable rectal cancer, with special emphasis on treatment morbidity, pathologic remission rate, quality of life, and anorectal function.

METHODS

Forty-two patients (30 men, 12 women) were enrolled in the study. Median distance of the distal tumor margin from the anal verge was 6.5 cm. Preoperative staging was based on digital rectal examination, endorectal ultrasound, and computed tomography. None of the patients had distant metastases. All patients had 45 Gy (1.8 Gy/day in 25 fractions) over five weeks, plus 5-fluorouracil (350 mg/m(2)/day) and leucovorin (20 mg/m(2)/day) bolus on days 1 to 5 and 29 to 33. Quality of life was assessed with the European Organization for Research and Treatment of Cancer 30-item quality-of-life questionnaire (QLQ-C30) and its colorectal cancer-specific module (QLQ-CR38) questionnaires. Objective anorectal function was assessed by anorectal manometry and pudendal nerve terminal motor latency. Surgery was performed 46 (range, 24-63) days after completion of adjuvant therapy.

RESULTS

Nineteen patients (45 percent) had Grade 3 or 4 chemoradiation-induced toxic reactions. Four patients developed intercurrent distant metastases or intraperitoneal carcinomatosis at completion of chemoradiation. Thirty-eight patients underwent surgical resection: abdominoperineal resection, anterior resection, and Hartmann's procedure were performed in 55 percent, 39 percent (11 of 15 patients had a diverting stoma), and 5 percent, respectively. Major surgical complications occurred in 7 patients (18 percent) and included anastomotic leak (n = 1), pelvic abscess (n = 1), small-bowel obstruction (n = 3), and wound breakdown (n = 2). Final pathology was Stage 0 (no residual disease), I, II, and III in 6 (16 percent), 7 (18 percent), 9 (24 percent), and 16 (42 percent) patients, respectively. There was a deterioration, after chemoradiation and surgery, in the quality of life on all subscales assessed, with physical, role, and social function being most severely affected. The symptoms most adversely affected were micturition, defecation, and gastrointestinal problems. Body image and sexual enjoyment deteriorated in both men and women. Chemoradiation alone led to prolonged pudendal nerve terminal motor latency in 57 percent of 7 patients assessed.

CONCLUSION

Preliminary results have identified defined costs with preoperative chemoradiation, which included treatment-induced toxicity, a high stoma rate, and adverse effects on quality of life and anorectal function.

Colorectal carcinoma associated with serrated adenoma--prevalence, histological features, and prognosis

Serrated adenoma has been proposed to be a distinct entity among colorectal neoplasms. Progression to frank carcinoma has been suggested in individual cases, but the prevalence of carcinomas originating from serrated adenomas and their clinico-pathological characteristics are not known. In the present study, a large series of colorectal cancers was analysed for the occurrence of serrated adenoma in association with carcinoma and clinico-pathological features were compared in cases with and without serrated adenoma. Specimens from 466 colorectal carcinoma patients undergoing operations between 1986 and 1996 were re-evaluated for the presence of juxtaposed serrated adenoma and carcinoma. Clinico-pathological features such as location, Dukes' stage, histological grade, mucinous differentiation, and prognosis were evaluated. Twenty-seven carcinomas (5.8%) were found in association with an adjacent serrated adenoma. Eight of the patients were male and 19 were female. All of these adenocarcinomas showed a serrated appearance resembling that of serrated adenomas. Nine (33%) cases were mucinous and a mucinous component was present in 11 (41%) additional cases. The majority of the tumours were located either in the caecum (14 cases; 51%) or in the rectum (9 cases; 33%). DNA microsatellite instability was more common in carcinomas associated with serrated adenoma (37.5%) than in other carcinomas (11.0%). It is concluded that carcinoma associated with serrated adenoma is a distinct type of colorectal neoplasm, accounting for 5.8% of all colorectal carcinoma cases in this study. Predilection for the caecum and the rectum may reflect their aetiological factors. Female preponderance is contrary to that reported for hyperplastic polyps and serrated adenomas.