Rectal cancer: the influence of tumor proliferation on response to preoperative irradiation

Neoadjuvant Chemotherapy or Neoadjuvant Chemoradiotherapy for Patients with Esophageal Squamous Cell Carcinoma: Real-World Data Comparison from A Japanese Nationwide Study

BACKGROUND

Although neoadjuvant treatment has become the standard of care for patients with locally advanced esophageal cancer, previous studies comparing neoadjuvant chemotherapy (NAC) and neoadjuvant chemoradiotherapy (NACRT) have demonstrated inconclusive results.

METHODS

Our study cohort included 3978 patients from 85 institutions. Those who underwent NAC or NACRT followed by surgery for esophageal squamous cell carcinoma (ESCC) were eligible for inclusion. We used the inverse probability of treatment weighting (IPTW) method to compare the outcomes between NAC and NACRT.

RESULTS

Among the 3978 patients, 3777 (94.9%) received NAC and 201 (5.1%) received NACRT. After IPTW adjustment, the NACRT group had more patients with pathologically downstaged diseases and significantly better pathological response compared with the NAC group (p < 0.001); however, 5-year overall survival (OS), recurrence-free survival (RFS), and regional recurrence-specific survival (RRSS) were comparable between the groups. Subgroup analysis stratifying patients according to cT category showed that among cT1-2 patients, those in the NACRT group had significantly longer 5-year OS, RFS, and RRSS than those in the NAC group (P = 0.024, < 0.001, and 0.020, respectively). In contrast, no significant differences were observed among cT3-4a patients. The competing risks regression model showed comparable subdistribution hazard ratios for 10-year cancerous and noncancerous deaths between the NAC and NACRT groups.

CONCLUSIONS

Compared with NAC, NACRT for ESCC did not promote better survival despite better therapeutic effects and did not increase noncancerous deaths.

Development and Validation of a Predictive Model of Therapeutic Effect in Patients with Esophageal Squamous Cell Carcinoma Who Received Neoadjuvant Treatment: A Nationwide Retrospective Study in Japan

BACKGROUND

Neoadjuvant treatment has become the standard of care for patients with advanced esophageal cancer. However, few studies have elucidated the clinical factors that predict response to neoadjuvant therapy in a large multicenter cohort. We aimed to develop a predictive model of therapeutic effect in patients with esophageal squamous cell carcinoma (SCC) who received neoadjuvant treatment.

METHODS

This nationwide study included 4078 patients from 85 institutions. Patients who received neoadjuvant treatment followed by surgery for esophageal SCC were eligible. We developed a logistic regression model to predict good pathological therapeutic effects, and a predictive nomogram was generated by applying the logistic regression formula.

RESULTS

Among neoadjuvant regimens, cisplatin plus 5-fluorouracil (CF) was the most frequently used (60.2%), followed by docetaxel plus CF (DCF, 27.4%), CF with radiotherapy (CF-RT, 4.5%), adriamycin plus CF (3.6%), nedaplatin plus 5-fluorouracil (0.9%), and DCF-RT (0.5%). Multivariable analysis revealed that male sex, advanced cT category, and increased pretherapeutic SCC antigen level were independently associated with not achieving a good therapeutic effect. Moreover, intensified neoadjuvant regimens were independently associated with favorable therapeutic effects; DCF-RT elicited the best therapeutic effect, followed by CF-RT and DCF. A predictive model including nine commonly measured preoperative variables was generated, and the area under the curve was 0.679 (95% confidence interval: 0.658-0.700). This nomogram was also adequately validated internally.

CONCLUSIONS

The model developed in this study was validated and predicts the therapeutic effect in patients with esophageal SCC who received neoadjuvant treatment. This model might contribute to individualized treatment strategies.

Three-dimension amide proton transfer MRI of rectal adenocarcinoma: correlation with pathologic prognostic factors and comparison with diffusion kurtosis imaging

OBJECTIVES

To investigate the utility of 3D amide proton transfer (APT) MRI in predicting pathologic factors for rectal adenocarcinoma, in comparison with diffusion kurtosis imaging.

METHODS

Sixty-one patients with rectal adenocarcinoma were enrolled in this prospective study. 3D APT and diffusion kurtosis imaging (DKI) were performed. Mean APT-weighted signal intensity (APTw SI), mean kurtosis (MK), mean diffusivity (MD), and ADC values of tumors were calculated on these maps. Pathological analysis included WHO grades, pT stages, pN stages, and extramural venous invasion (EMVI) status. Student's t test, Spearman correlation, and receiver operating characteristics (ROC) analysis were used for statistical analysis.

RESULTS

High-grade rectal adenocarcinoma showed significantly higher mean APTw SI and MK values (2.771 ± 0.384 vs 2.108 ± 0.409, 1.167 ± 0.216 vs 1.045 ± 0.175, respectively; p < 0.05). T3 rectal adenocarcinoma demonstrated higher mean APTw SI and MK than T2 tumors (2.433 ± 0.467 vs 1.900 ± 0.302, p < 0.05). No kurtosis, diffusivity, and ADC differences were found between T2 and T3 tumors. Tumors with lymph node metastasis and EMVI involvement showed significantly higher mean APTw SI, MK. No difference was found in diffusivity and ADC between pN0 and pN1-2 groups, and EMVI-negative and EMVI-positive statuses. Mean APTw SI exhibited a significantly high positive correlation with WHO grades, demonstrating 92.31% sensitivity and 79.17% specificity for distinguishing low- from high-grade rectal adenocarcinoma, providing a better diagnostic capacity than MK, MD, and mean ADC values.

CONCLUSION

3D-APT could serve as a non-invasive biomarker for evaluating prognostic factors of rectal adenocarcinoma.

KEY POINTS

• Mean APTw SI was significantly higher in high-grade compared to low-grade rectal adenocarcinoma. • Mean APTw SI was significantly higher in T3 stage rectal adenocarcinoma, with lymph node metastasis, or in EMVI-positive status. • APTw SI exhibited greater diagnostic capability in discriminating low-grade from high-grade rectal adenocarcinoma, compared with kurtosis, diffusivity, and ADC.

Development of a nomogram for the prediction of pathological complete response after neoadjuvant chemoradiotherapy in patients with esophageal squamous cell carcinoma

Nomograms incorporating multiple prognostic factors are useful for individualized estimation of survival in cancer patients. However, nomograms for the prediction of pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in patients with esophageal cancer are scarce. Here, we describe the development of a nomogram for predicting pCR after nCRT in patients with esophageal squamous cell carcinoma (ESCC). We retrospectively reviewed the records of 392 ESCC patients who underwent nCRT followed by esophagectomy. Seventy percent of the participants (n = 274) were randomly assigned to a training cohort, whereas the remaining 30% were included in a validation cohort (n = 118). Data from the training cohort were subjected to multivariate logistic regression analyses for selecting variables to be included in the nomogram. The performance of the resulting nomogram was internally and externally validated by calculating the bias-corrected concordance statistic (c-statistic) and the area under the receiver operating characteristics curve (AUROC) in the training and validation cohorts, respectively. After surgery, 25.77% of the study patients achieved pCR. The following variables were included in the nomogram: (i) age, (ii) pretreatment tumor length, (iii) history of head and neck cancer, (iv) post-nCRT albumin levels, and (v) post-nCRT endoscopic findings coupled with endoscopic biopsy results. The bias-corrected c-statistic and AUROC of the internal and external validation sets were 0.77 and 0.747, respectively. Our nomogram showed a good performance for predicting pCR after nCRT in ESCC patients.

Impact of neoadjuvant therapy in downstaging of lower rectal adenocarcinoma and the role of pelvic magnetic resonance in staging

ABSTRACT Objective: to evaluate the effect of neoadjuvant therapy on the stage (TNM) of patients with rectal adenocarcinoma and validate the use of MRI as a method of determining locoregional stage. Methods: we conducted a retrospective study of 157 patients with lower rectum adenocarcinoma, whom we divided into two groups: Group 1, 81 patients (52%) who had undergone surgical treatment initially, with the purpose to analyze the accuracy of locoregional staging by pelvic magnetic resonance imaging throug the comparison of radiological findings with pathological ones; Group 2, 76 patients (48%), who had been submitted to neoadjuvant therapy (chemotherapy and radiation) prior to definitive surgical treatment, so as to evaluate its effects on the stage by comparing clinical and radiological findings with pathology. Results: In group 1, the accuracy of determining tumor depth (T) and lymph node involvement (N) was 91.4% and 82.7%, respectively. In group 2, neoadjuvant therapy decreased the T stage, N stage and TNM stage in 51.3%, 21% and 48.4% of cases, respectively. Conclusion: neoadjuvant therapy in patients with rectal adenocarcinoma is effective in decreasing disease stage, and pelvic magnetic resonance imaging is effective for locoregional staging.

Pathological Assessment of the AJCC Tumor Regression Grading System After Preoperative Chemoradiotherapy for Chinese Locally Advanced Rectal Cancer

We used American Joint Committee on Cancer (AJCC) Staging Manual system to assess the prognostic significance of tumor regression grading (TRG) for locally advanced rectal cancer (LARC) (T3/4 or N+) patients who were treated with preoperative chemoradiotherapy (CRT).The 4 AJCC-TRG classifications were evaluated on surgical specimens from 295 LARC patients receiving CRT. Overall survival (OS), disease-free survival (DFS), local recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were estimated using Kaplan-Meier method and Cox regression model.Classifications of TRG 0, 1, 2, and 3 were found in 27.5%, 19.3%, 45.7%, and 7.5% of the resected specimens, respectively. Three-year OS was 95.5% for TRG0, 91.5% for TRG1, 84.8% for TRG2, and 85.7% for TRG3 (P = 0.035). Three-year DFS was 89.0% for TRG0, 74.4% for TRG1, 70.9% for TRG2, and 62% for TRG3 (P = 0.018). By multivariate analysis, AJCC-TRG (P = 0.033), residual lymph node metastasis (ypN+) (P < 0.001) and pretreatment CA19-9 level (P = 0.035) were significant predictors of OS. Pathological T category (P = 0.006) and nodal status (P < 0.001) after CRT were the most important independent prognostic factors for DFS.AJCC-TRG is a prognostic factor for LARC patients receiving CRT, independent of pathological staging.

Carcinoembryonic antigen has prognostic value for tumor downstaging and recurrence in rectal cancer after preoperative chemoradiotherapy and curative surgery: A multi-institutional and case-matched control study of KROG 14-12

BACKGROUND AND PURPOSE

The Korean Radiation Oncology Group evaluated the significance of carcinoembryonic antigen (CEA) levels both as a predictor of tumor response after CRT and as a prognosticator for recurrence-free survival.

METHODS AND MATERIALS

1804 rectal cancer patients, staged cT3-4N0-2M0, participated in a multicenter study. The patients were administered preoperative radiation of 50.4 Gy in 28 fractions with 5-FU or capecitabine, followed by total mesorectal excision. Patients with elevated CEA levels (>5 ng/mL) were matched at a 1 (n=595):1 (n=595) ratio with patients with normal CEA (⩽5 ng/mL). The tumor response after CRT and the recurrence-free survival (RFS) rates were evaluated and compared between two arms.

RESULTS

An elevated CEA level (p<0.001) was determined to be a significant negative predictor of downstaging after CRT. The downstaging rate was 42.9% for normal CEA and 23.4% for elevated CEA. A multivariate analysis also revealed that cT (p=0.021) and cN classification (p=0.001), tumor size (p=0.002), and tumor location from the anal verge (p=0.006) were significant predictors for tumor downstaging. The 5-year RFS rates were significantly higher for the normal CEA arm than for the elevated CEA arm (74.2 vs. 63.5%, p<0.001).

CONCLUSIONS

Elevated CEA (>5 ng/mL) is a negative predictor of tumor downstaging after CRT and also has a negative impact on RFS in rectal cancer.

Neutrophil-lymphocyte ratio predicts pathologic tumor response and survival after preoperative chemoradiation for rectal cancer

Background

Neutrophil-lymphocyte ratio (NLR) reflects the balance between pro- and anti-tumor immune activities. We evaluated whether NLR is associated with pathologic tumor response and prognosis in rectal cancer patients that underwent preoperative chemoradiaton therapy (CRT) with surgery.

Methods

One hundred two patients with rectal cancer that were treated by preoperative CRT followed by surgery were enrolled. A total of 50.4 GY of radiation and 5-FU-based chemotherapy were delivered. An NLR ≥ 3 was considered to be elevated. Pathologic tumor response based on ypTNM stage was categorized into two groups, good response (n = 35, pathologic complete response and ypTNM I) and poor response groups (n = 67, ypTNM II, III, and IV).

Results

Twenty-five patients (24.5%) had elevated NLR. Multivariate analysis showed that an elevated CEA level (p = 0.001), larger tumor (p = 0.03), and elevated NLR (p = 0.04) were significant predictors for a poor response. Poor pathological tumor response and elevated NLR were risk factors for cancer-specific and recurrence-free survivals.

Conclusion

An elevated NLR before CRT can be used as predictors for poor tumor response and unfavorable prognostic factors. Dominant pro-tumor activities of neutrophils or reduced anti-tumor immune response by lymphocytes, as determined by NLR, may have a impact on poor tumor response and unfavorable prognosis.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2482-14-94) contains supplementary material, which is available to authorized users.

Predictors of pathological complete response to neoadjuvant chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUNDS

In this study, we evaluated the factors associated with a pathologic complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for esophageal squamous cell carcinoma (ESCC).

METHODS

Pre-nCRT parameters in ESCC patients treated between 1999 and 2006 were analyzed to identify predictors of pCR. All patients received 5-fluorouracil/cisplatin-based chemotherapy and external beam radiation followed by scheduled esophagectomy. Variables were analyzed using univariate and multivariate analyses with pCR as the dependent variable. Estimated pCR rate was calculated with a regression model.

RESULTS

Fifty-nine (20.9%) of 282 patients achieved pCR. Univariate analysis identified four patient factors (age, smoking status, drinking history and hypertension), one pre-nCRT parameter (tumor length) as significant predictors of pCR (all P <0.05). On multivariate analysis, tumor length ≤3 cm (favorable, odds ratio (OR): 4.85, P = 0.001), patient age >55 years (favorable, OR: 1.95, P = 0.035), and being a non-smoker (favorable, OR: 3.6, P = 0.003) were independent predictors of pCR. The estimated pCR rates based on a logistic regression including those three predictors were 71%, 35 to approximately 58%, 19 to approximately 38%, and 12% for patients with 3, 2, 1 and 0 predictors, respectively.

CONCLUSION

Age, smoking habit and tumor length were important pCR predictors. These factors may be used to predict outcomes for ESCC patients receiving nCRT, to develop risk-adapted treatment strategies, and to select patients who could participate in trials on new therapies.

Gender-related differences in repopulation and early tumor response to preoperative radiotherapy in rectal cancer patients

PURPOSE

Inhibition of tumor proliferation rate based on bromodeoxyuridine labelling index (BrdUrdLI), S-phase fraction (SPF) and MIB-1 labelling index (MIB-1 LI) as an early rectal cancer response to preoperative radiotherapy (RT).

METHODS AND MATERIALS

A total of 122 patients qualified either for short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I) or for short RT and a 4-week interval before surgery (schedule II). Tumor samples were taken twice from each patient: before RT and at the time of surgery. In each sample, the BrdUrdLI, SPF and MIB-1 were calculated. Early tumor response was assessed by a biologist, a pathologist and surgeons.

RESULTS

Fifty-six patients were treated according to schedule I and 66 patients according to schedule II. Mean BrdUrdLI, SPF and MIB-1 LI before RT were 8.8%, 21.0% and 53.3%, respectively, and these values did not differ between the two compared groups. After RT, tumors showed statistically significant growth inhibition based on all assessed biological markers. As pretreatment assessed parameter was not predictive for early clinical and pathologic tumor response, prognostic role of the relative value (RV), that is, the ratio of assessed parameter after RT to before RT for each of the assessed markers, was considered. The ratios were calculated separately for fast and slowly proliferating tumors and separately for male and female patients. Fast proliferating tumors were more responsive. Differences with regard to sex were visible only in slowly proliferating tumors. Accelerated cell repopulation (4.8-28%/day) was noticed in female slowly proliferating tumors about 4 weeks after RT. Only for relative MIB-1 LI it was possible to show significant correlation with pathological tumor regression. Lack of such correlation for BrdUrdLI and SPF might reflect accelerated repopulation, particularly in slowly proliferating female tumors.

CONCLUSIONS

Accelerated repopulation was noticed in slowly proliferating tumors in females about 4 weeks after RT.

Clinicopathologic variables predicting tumor response to neoadjuvant chemotherapy in patients with locally advanced gastric cancer

BACKGROUND AND OBJECTIVES

To identify clinicopathologic variables that could predict pathologic tumor response to neoadjuvant chemotherapy for patients with locally advanced gastric cancer.

METHODS

The study enrolled 108 patients who underwent neoadjuvant chemotherapy followed by surgery between July 2004 and December 2010. Tumor responses to neoadjuvant chemotherapy were assessed in terms of tumor regression. Statistical analyses were performed to identify factors associated with pathologic tumor response.

RESULTS

Tumor regression was found in 22.2% (24/108) patients, patients with tumor regression observed better overall survival as compared to that of patients without tumor regression. Univariate and multivariate analyses observed that both tumor differentiation and tumor size were independent predictors of tumor regression.

CONCLUSIONS

This study suggests that both tumor differentiation and tumor size is the most important clinical predicator of pathologic tumor response, it may be of benefit in the selection of treatment options in locally advanced gastric cancer.

[Predictive factors of tumour response after neoadjuvant chemoradiation for locally advanced rectal cancer and correlation of these factors with survival]

PURPOSE

Neoadjuvant chemoradiation followed by surgery is the standard of care for locally advanced rectal cancer. The aim of this study was to correlate tumour response to survival and to identify predictive factors for tumour response after chemoradiation.

PATIENTS AND METHODS

From 1998 to 2008, 168 patients with histologically-proven locally advanced adenocarcinoma treated by preoperative chemoradiation before total mesorectal excision were retrospectively studied. They received a radiation dose of 45 Gy with a concomitant 5-fluoro-uracil-based chemotherapy. Analysis of tumour response was based on the lowering of T stage between pre-treatment endorectal ultrasound and pathologic specimens. Overall and progression-free survival was correlated with tumour response. Tumour response was analysed with predictive factors.

RESULTS

The median follow-up was 34 months. Five-year disease-free survival and overall survival were respectively of 44.4% and 74.5% in the whole population, 83.4% and 83.4% in patients with pathological complete response, 38.6% and 71.9% in patients with tumour downstaging, 29.1% and 58.9% in patients with absence of response. A pre-treatment concentration of carcinoembryonnic antigen below 5 ng/mL was significantly associated with tumour downstaging and significantly independently associated with pathologic complete tumour response (P = 0.019).

CONCLUSION

Downstaging and complete response after chemoradiation improved progression-free survival and overall survival of locally advanced rectal adenocarcinoma. In multivariate analysis, a pre-treatment concentration of carcinoembryonnic antigen below 5 ng/mL was associated with complete tumour response, hence with tumour downstaging.

Clinical impact of tumor regression grade after preoperative chemoradiation for locally advanced rectal cancer: subset analyses in lymph node negative patients

BACKGROUND

We investigated the prognostic significance of tumor regression grade (TRG) after preoperative chemoradiation therapy (preop-CRT) for locally advanced rectal cancer especially in the patients without lymph node metastasis.

METHODS

One-hundred seventy-eight patients who had cT3/4 tumors were given 5,040 cGy preoperative radiation with 5-fluorouracil/leucovorin chemotherapy. A total mesorectal excision was performed 4-6 weeks after preop-CRT. TRG was defined as follows: grade 1 as no cancer cells remaining; grade 2 as cancer cells outgrown by fibrosis; grade 3 as a minimal presence or absence of regression. The prognostic significance of TRG in comparison with histopathologic staging was analyzed.

RESULTS

Seventeen patients (9.6%) showed TRG1. TRG was found to be significantly associated with cancer-specific survival (CSS; P = 0.001) and local recurrence (P = 0.039) in the univariate study, but not in the multivariate analysis. The ypN stage was the strongest prognostic factor in the multivariate analysis. Subgroup analysis revealed TRG to be an independent prognostic factor for the CSS of ypN0 patients (P = 0.031). TRG had a stronger impact on the CSS of ypN (-) patients (P = 0.002) than on that of ypN (+) patients (P = 0.521). In ypT2N0 and ypT3N0, CSS was better for TRG2 than for TRG3 (P = 0.041, P = 0.048), and in ypN (-) and TRG2 tumors, CSS was better for ypT1-2 than for ypT3-4 (P = 0.034).

CONCLUSION

TRG was found to be the strongest prognostic factor in patients without lymph node metastasis (ypN0), and different survival was observed according to TRG among patients with a specific histopathologic stage. Thus, TRG may provide an accurate prediction of prognosis and may be used for f tailoring treatment for patients without lymph node metastasis.

Predictive factors of tumor response after neoadjuvant chemoradiation for locally advanced rectal cancer

PURPOSE

Neoadjuvant chemoradiation followed by surgery is the standard of care for locally advanced rectal cancer. The aim of this study was to correlate tumor response to survival and to identify predictive factors for tumor response after chemoradiation.

METHODS AND MATERIALS

From 1998 to 2008, 168 patients with histologically proven locally advanced adenocarcinoma treated by preoperative chemoradiation before total mesorectal excision were retrospectively studied. They received a radiation dose of 45 Gy with a concomitant 5-fluorouracil (5-FU)-based chemotherapy. Analysis of tumor response was based on lowering of the T stage between pretreatment endorectal ultrasound and pathologic specimens. Overall and progression-free survival rates were correlated with tumor response. Tumor response was analyzed with predictive factors.

RESULTS

The median follow-up was 34 months. Five-year disease-free survival and overall survival rates were, of 44.4% and 74.5% in the whole population, 83.4% and 83.4%, respectively, in patients with pathological complete response, 38.6% and 71.9%, respectively, in patients with tumor downstaging, and 29.1 and 58.9% respectively, in patients with absence of response. A pretreatment carcinoembryonic antigen (CEA) level of <5 ng/ml was significantly independently associated with pathologic complete tumor response (p = 0.019). Pretreatment small tumor size (p = 0.04), pretreatment CEA level of <5 ng/ml (p = 0.008), and chemotherapy with capecitabine (vs. 5-FU) (p = 0.04) were significantly associated with tumor downstaging.

CONCLUSIONS

Downstaging and complete response after CRT improved progression-free survival and overall survival of locally advanced rectal adenocarcinoma. In multivariate analysis, a pretreatment CEA level of <5 ng/ml was associated with complete tumor response. Thus, small tumor size, a pretreatment CEA level of < 5 ng/ml, and use of capecitabine were associated with tumor downstaging.

Clinical significance of tumor regression grade in rectal cancer with preoperative chemoradiotherapy

Purpose

Neoadjuvant chemoradiotherapy applied to the locally advanced rectal cancer reduces local recurrence and improves survival. We assessed tumor regression grade (TRG) and its influence on survival in rectal cancer patients treated with chemoradiotherapy followed by surgical resection.

Methods

We studied 108 patients that were seen at our hospital between August 2004 and December 2008. Patients received preoperative chemoradiotherapy consisting of 5-fluorouracil and leucovorin by continous infusion during the first and fifth week, delivered with concurrent pelvic radiation of 50.4 Gy, followed by radical surgery at 6-8 weeks. The TRG was determined by the amount of fibrosis in the tumor embedding area and was divided into 5 grades based on the relative amount of fibrosis. We analyzed all preoperative clinicopathologic factors, postoperative pathologic stages, TRG and prognosis, retrospectively.

Results

Downstaging of rectal cancer through neoadjuvant chemoradiotherapy occurred in 64 (59%) patients. The numbers of total regressions (TRG4), good regressions (TRG3), moderate regressions (TRG2), minor regressions (TRG1), and no regression (TRG0) were 19 (18%), 65 (60%), 17 (16%), 6 (5%), and 1 (1%) respectively. The TRG was inversely correlated with perineural invasion and lymphovascular invasion (P = 0.008, P = 0.032). The local recurrence rate declined as the tumor regression grade increased (P = 0.032). The 19 patients with TRG4 had a better three-year disease free survival than the 89 patients with TRG0-3 (P = 0.034). The 16 patients with pathologic complete remission (pCR) had a better three-year disease free survival than the 92 patients with non-pCR (P = 0.025).

Conclusion

Higher TRG after preoperative chemoradiotherapy for rectal cancer closely correlates with better survival and low local recurrence. The TRG is considered to be a significant prognostic factor.

Mechanisms of resistance to ionizing radiation in rectal cancer

While patients with breast cancers are not subjected to the adverse side effects of tamoxifen or trastuzumab if their tumors are negative for estrogen, progesterone or Her-2/Neu, neoadjuvant ionizing radiation with concurrent chemotherapeutic agents is administered almost universally to patients with stage II/III rectal cancers. There is, however, a tremendously wide range of response to this preoperative modality from complete pathological response to continuous tumor growth in patients receiving the same form of treatment. The specific phenotype of the tumor plays a major role in rendering tumor cells survival advantage to the cytotoxic effects of chemoradiation. Pathways such as proliferation, cell cycle, apoptosis and hypoxia have been investigated under a variety of conditions in preirradiated tissues and postirradiated tumors. This article reviews the current evidence available to identify a molecular profile predictive of the best response to ionizing radiation.

Molecular genetic changes associated with colorectal carcinogenesis are not prognostic for tumor regression following preoperative chemoradiation of rectal carcinoma

PURPOSE

Preoperative chemotherapy and radiation has become the standard of care for many patients with rectal cancer. The therapy may have toxicity and delays definitive surgery. It would therefore be desirable to identify those cancers that will not regress with preoperative therapy. We assessed a series of rectal cancers for the molecular changes of loss of heterozygosity of the APC and DCC genes, K-ras mutations, and microsatellite instability, changes that have clearly been associated with rectal carcinogenesis.

METHODS AND MATERIALS

Diagnostic colonoscopic biopsies from 53 patients who received preoperative chemotherapy and radiation were assayed using polymerase chain reaction techniques followed by single-stranded conformation polymorphism and DNA sequencing. Regression of the primary tumor was evaluated using the surgically removed specimen.

RESULTS

Twenty-three lesions (45%) were found to have a high degree of regression. None of the molecular changes were useful as indicators of regression.

CONCLUSIONS

Recognized molecular changes critical for rectal carcinogenesis including APC and DCC loss of heterozygosity, K-ras mutations, and microsatellite instability are not useful as indicators of tumor regression following chemoradiation for rectal carcinoma.

Pathologic response assessed by Mandard grade is a better prognostic factor than down staging for disease-free survival after preoperative radiochemotherapy for advanced rectal cancer

OBJECTIVE

The reduction in tumour stage induced by full course radiotherapy plus chemotherapy is apparent from histological changes. The purpose of this study was to determine the rate of complete pathological response and to evaluate the prognostic value for disease free survival (DFS) and disease specific survival (DSS) of the response. The relation between pretreatment variables (age, gender, stage, tumour height and [carcinoembryogenic antigen (CEA)] and postsurgical variables was compared to the pathological response.

METHOD

A total of 119 patients with stage II or III rectal cancer underwent surgery 6 weeks after neoadjuvant treatment. Group A included patients with a complete or good pathological response (Mandard grade I-II) and group B patients with a poor response (Mandard grade III-IV-V). The pretreatment endo-rectal ultrasound scan stage was compared with histopathology stage of the resected specimen. DFS and DSS were compared using the log-rank test.

RESULTS

All 119 patients (mean age 67.9 years, 83 males) underwent resection. The tumour was located in the upper, middle and lower third of the rectum in 11, 51 and 57 patients. 88 patients had a low anterior resection, 28 patients abdomino-perineal resection and three a Hartmann's operation. There was no postoperative death. The circumferential margin (CM) was involved in 10%. A complete pathological response was observed in 17 (14.2%) patients. Thirty-six (30.2%) patients had a group A and 83 a group B response. Group A showed DFS to be significantly higher than group B (log rank: P = 0.007). The DSS rate was not significantly different between the two groups (log rank P = 0.113). Down-staging was not related with DFS. No relation was found between pretreatment variables and response. A good pathological response was related to a lower rate of permanent colostomy but not with CM involvement or the number of lymph nodes.

CONCLUSION

Tumour regression of grades I or II was a good indicator of DFS in locally advanced rectal cancer, treated by neoadjuvant chemotherapy and radiotherapy. Patients with a high regression grade were associated with a lower incidence of definitive stoma formation. The regression grade was shown to be a better prognostic factor than down-staging.

High MUC2 immunohistochemical expression is a predictor of poor response to preoperative radiochemotherapy (RCT) in rectal adenocarcinoma

The purpose of this study is to establish if mucoid differentiation is associated with responsiveness to preoperative radiochemotherapy (RCT) in rectal adenocarcinomas. Thirty-two patients with rectal adenocarcinomas were preoperatively treated with 44 to 46 Gy in 22 to 23 fractions and with 5-fluorouracil (200 to 225 mg/m) before surgery. Mucoid differentiation was searched for both in pre-RCT biopsies with anti-MUC2 antiserum and in postoperative specimens. To evaluate the responsiveness to preoperative RCT, a regression grading was used (grades 0 to 4). Statistical analysis showed a significant negative correlation between immunohistochemical expression of MUC2 in pre-RCT biopsies and regression grade in postoperative specimens (r=-0.529; P=0.002). A significant cutoff value of 60% of MUC2 positive neoplastic cells in pre-RCT biopsies was observed (P=0.018): 13 cases with more than 60% exhibited a poor response to RCT (grade 0 in 5/13, grade 1 in 4/13, grade 2 in 4/13), whereas 19 cases with less than 60% showed a better response to RCT (grade 1 in 6/19, grade 2 in 9/19, grade 3 in 3/19, grade 4 in 1/19).

Clinical parameters predicting pathologic tumor response after preoperative chemoradiotherapy for rectal cancer

PURPOSE

To identify pretreatment clinical parameters that could predict pathologic tumor response to preoperative chemoradiotherapy (CRT) for rectal cancer.

METHODS AND MATERIALS

The study involved 351 patients who underwent preoperative CRT followed by surgery between October 2001 and July 2006. Tumor responses to preoperative CRT were assessed in terms of tumor downstaging and tumor regression. Statistical analyses were performed to identify clinical factors associated with pathologic tumor response.

RESULTS

Tumor downstaging (defined as ypT2 or less) was observed in 167 patients (47.6%), whereas tumor regression (defined as Dworak's Regression Grades 3 or 4) was observed in 103 patients (29.3%) and complete regression in 51 patients (14.5%). Multivariate analysis found that predictors of downstaging were pretreatment hemoglobin level (p = 0.045), cN0 classification (p < 0.001), and serum carcinoembryonic antigen (CEA) level (p < 0.001), that predictors of tumor regression were cN0 classification (p = 0.044) and CEA level (p < 0.001), and that the predictor of complete regression was CEA level (p = 0.004).

CONCLUSIONS

The data suggest that pretreatment CEA level is the most important clinical predictor of pathologic tumor response. It may be of benefit in the selection of treatment options as well as the assessment of individual prognosis.

Non-operative treatment after neoadjuvant chemoradiotherapy for rectal cancer

The past decade has seen pronounced changes in the treatment of locally advanced rectal cancer. Historically, the standard of care involved surgery followed by adjuvant radiotherapy or chemoradiotherapy. More recently, the emergence of neo-adjuvant chemoradiotherapy has fundamentally changed the management of patients with locally advanced disease. In clinical trials, pathological complete responses of up to 25% have raised the question as to whether surgery can be avoided in a select cohort of patients. A trial of omission of surgery for selected patients with complete response after preoperative chemoradiotherapy has shown favourable long-term results. In this article, we outline emerging factors for achieving pathological complete response, non-operative strategies to date, methods for prediction of response to chemoradiotherapy, and future directions with the addition of MRI as a radiological guide to complete response.

Bromodeoxyuridine labeling index as an indicator of early tumor response to preoperative radiotherapy in patients with rectal cancer

PURPOSE

Assessment of tumor proliferation rate using Bromodeoxyuridine labeling index (BrdUrdLI) as a possible predictor of rectal cancer response to preoperative radiotherapy (RT).

METHODS AND MATERIAL

Ninety-two patients were qualified either to short RT (5 Gy/fraction/5 days) and surgery about 1 week after RT (schedule I), or to short RT and 4-5 weeks interval before surgery (schedule II). Tumor samples were taken twice from each patient: before RT and at the time of surgery. The samples were incubated with BrdUrd for 1 h at 37 degrees C, and the BrdUrdLI was calculated as a percentage of BrdUrd-labeled cells.

RESULTS

Thirty-eight patients were treated according to schedule I and 54 patients according to schedule II. Mean BrdUrdLI before RT was 8.5% and its value did not differ between the patients in the two compared groups. After RT tumors showed statistically significant growth inhibition (reduction of BrdUrdLI). As the pretreatment BrdUrd LI was not predictive for early clinical and pathologic tumor response, prognostic role of the ratio of BrdUrdLI after to BrdUrdLI before RT was considered. The ratios were calculated separately for fast (BrdUrd LI>8.5%) and slowly (BrdUrd LI<or=8.5%) proliferating tumors and correlated with overall treatment time (OTT, i.e., time from the first day of RT to surgery). One month after RT, accelerated proliferation was observed only in slowly proliferating tumors.

CONCLUSIONS

Pretreatment BrdUrdLI was not predictive for early clinical and pathologic tumor response. The ratio after/before RT BrdUrdLI was correlated to inhibition of proliferation in responsive tumors.

Association between pathologic response in metastatic lymph nodes after preoperative chemoradiotherapy and risk of distant metastases in rectal cancer: An analysis of outcomes in a randomized trial

PURPOSE

To compare 5 x 5 Gy preoperative radiotherapy with immediate surgery vs. preoperative chemoradiotherapy (50.4 Gy, 5-fluorouracil, leucovorin) with delayed surgery in a randomized trial for cT3-T4 low-lying rectal cancer. Despite the downstaging effect of chemoradiotherapy, similar long-term outcomes were observed in both groups.

METHODS

The Cox model was used to evaluate the prognostic value of ypTN ("yp" denotes that pathologic classification was performed after initial multimodality therapy) categories and the surgical margin status in 291 patients.

RESULTS

Disease-free survival (DFS) (hazard ratio [HR] 1.05, 95% confidence interval [CI], 0.73-1.51), distant metastases (HR, 1.17; 95% CI, 0.77-1.78), and local control (HR, 1.45; 95% CI, 0.74-2.84) were similar in both arms. The ypN status was the only independent prognostic factor for DFS (p < 0.001). An interaction (p = 0.016) between N stage and the assigned treatment was demonstrated. For ypN-negative patients, DFS was similar in both arms (HR, 0.83, 95% CI, 0.47-1.48); however, for ypN-positive patients, DFS was worse in the chemoradiotherapy arm (HR, 1.73; 95% CI, 1.07-2.77). The 4-year (median follow-up) DFS rate in N-positive patients was 51% in the 5 x 5-Gy arm vs. 25% in the chemoradiotherapy arm. The corresponding 4-year rates for the incidence of local recurrence and distant metastases were 14% vs. 27% (HR, 1.95; 95% CI, 0.78-4.86) and 38% vs. 68% (HR, 2.05; 95% CI, 1.21-3.48).

CONCLUSION

N-positive disease after chemoradiotherapy indicates radiochemoresistance. N-positive disease after 5 x 5 Gy RT includes both radiosensitive and radioresistant tumors, because the interval between radiotherapy and surgery was too short for radiosensitive cancer to undergo necrosis. Thus, the greater risk of distant metastases recorded in the chemoradiotherapy arm suggests that radiochemoresistance of nodal metastases from rectal cancer is associated with a high potential for developing distant metastases.

A comparative study of volumetric analysis, histopathologic downstaging, and tumor regression grade in evaluating tumor response in locally advanced rectal cancer following preoperative chemoradiation

PURPOSE

To compare tumor volume reduction rate, histopathologic downstaging, and tumor regression grade (TRG) among tumor responses in rectal cancer after preoperative chemoradiotherapy (CRT).

PATIENTS AND METHODS

Between 2002 and 2004, 30 patients with locally advanced rectal cancer underwent preoperative CRT, followed by surgical resection. Magnetic resonance volumetry was performed before and after CRT. Histopathologic tumor staging and tumor regression were reviewed. We compared pre- and post-CRT tumor volume and percent of volume reduction, according to histopathologic downstaging and TRG.

RESULTS

The tumor volume reduction rates ranged from 14.6% to 100%. Mean pre- and post-CRT tumor volumes were significantly smaller in patients who showed T downstaging than in those who did not (p = 0.040, 0.014). The mean tumor volume reduction was 66.4% vs. 55.2% (p = 0.361). However, the mean pre- and post-CRT tumor volume and mean tumor volume reduction rate between patients who showed N downstaging and those who did not were not statistically different (p = 0.176, 0.767, and 0.899). With respect to TRG, the mean pre- and post-CRT tumor volumes were not statistically significant (p = 0.108, 0.708, and 0.120).

CONCLUSION

Tumor volume reduction rate does not correlate with histopathologic downstaging and TRG. It might be hazardous to evaluate tumor response with respect to volume reduction and to select the surgical method on this basis.

Oncocytic modifications in rectal adenocarcinomas after radio and chemotherapy

The purpose of the study is to highlight oncocytic modifications in rectal adenocarcinomas and evaluate a possible correlation with preoperative radiochemotherapy (RCT). Twenty-eight cases of advanced rectal carcinoma, treated preoperatively by 5-fluorouracil (200-225 mg/m(2)) and 44-46 Gy in 22-23 fractions, were studied. All patients underwent biopsy before RCT. Surgery was performed within 6 weeks after RCT. In all cases oncocytic modifications were searched for on hematoxylin and eosin (H&E) and at immunohistochemistry using an antimitochondrial antibody. In addition, in two cases, both pre- and post-RCT tissues were examined at electron microscopy. All tumors were adenocarcinomas. In pre-RCT biopsies, oncocytic changes were difficult to find on H&E, while the antimitochondrial antibody strongly stained numerous neoplastic cells (mean 48.4%). In post-RCT surgical specimens, oncocytic changes were detected in 24 out of 28 cases on H&E and the antimitochondrial antibody stained most of the residual neoplastic cells (mean 76.7%). Ultrastructural examination revealed large and bizarre mitochondria inside tumor cells both in pre- and post-RCT tissues. In conclusion, the present data suggest that rectal adenocarcinomas are "mitochondrion-rich" tumors. After preoperative RCT, residual neoplastic cells acquire a definite oncocytic phenotype.

Prognostic Significance of Tumor Regression After Preoperative Chemoradiotherapy for Rectal Cancer

Purpose

We assessed the impact of tumor regression grading (TRG) and its value in correlation to established prognostic factors in a cohort of rectal carcinoma patients treated by preoperative chemoradiotherapy (CRT).

Patients and Methods

TRG was evaluated on surgical specimens of 385 patients treated within the preoperative CRT arm of the CAO/ARO/AIO-94 trial: 50.4 Gy was delivered, fluorouracil was given in the first and fifth week, and surgery was performed 6 weeks thereafter. TRG was determined by the amount of viable tumor versus fibrosis, ranging from TRG 4 when no viable tumor cells were detected, to TRG 0 when fibrosis was completely absent. TRG 3 was defined as regression more than 50% with fibrosis outgrowing the tumor mass, TRG 2 was defined as regression less than 50%, and TRG 1 was defined basically as a morphologically unaltered tumor mass. We performed an initially unplanned, hypothesis-generating analysis with respect to the prognostic value of this TRG system.

Results

TRG 4, 3, 2, 1, 0 was found in 10.4%, 52.2%, 13.8%, 15.3%, and 8.3% of the resected specimens, respectively. Five-year disease-free survival (DFS) after CRT and curative resection was 86% for TRG 4, 75% for grouped TRG 2 + 3, and 63% for grouped TRG 0 + 1 (P = .006). On multivariate analysis, the pathologic T category and the nodal status after CRT were the most important independent prognostic factors for DFS.

Conclusion

In this exploratory analysis, complete (TRG 4) and intermediate pathologic response (TRG 2 + 3) suggested improved DFS after preoperative CRT. TRG assessment should be implemented in pathologic evaluation and prospectively validated in further studies.

High intrinsic apoptosis, but not radiation-induced apoptosis, predicts better survival in rectal carcinoma patients

PURPOSE

An important feature of malignant tumors is the disturbance in the balance between proliferation and cell death. We evaluated the relevance of intrinsic and radiation-induced apoptosis and proliferation for prognosis in rectal cancer patients.

METHODS AND MATERIALS

Patients were selected from a study that randomized for preoperative radiotherapy (RT). Apoptosis and proliferation were scored using specific antibodies in immunohistochemistry. The number of positive cells per square millimeter of carcinoma cells was determined in 98 randomly selected tumors, of which 45 had been irradiated. For the survival analyses, a cohort of 104 patients without positive circumferential resection margins was selected.

RESULTS

In nonirradiated patients, high levels of intrinsic apoptosis correlated with better local control (p = 0.04) and better cancer-specific survival (p = 0.02). RT increased the median amount of apoptosis from 10.8 to 21.5 cells/mm(2) (p = 0.004), but this was not predictive for survival. The amount of proliferative cells was not altered after RT and had no influence on prognosis.

CONCLUSIONS

Intrinsic apoptosis correlated with both local control and cancer-specific survival, but proliferation was not predictive for prognosis. However, although RT increased apoptosis, its prognostic value was lost after RT. This is possibly because in rectal cancer, the proliferative status of tumors is always high and the aggressiveness of the tumor is determined by the number of "spontaneous" apoptotic tumor cells.

Rectal cancer: the sphincter-sparing approach

There is considerable skepticism regarding sphincter-preserving surgery for rectal cancer, and 40% to 60% APR rates are reported in many prospective studies. Despite radical surgery, 20% positive margin rates are frequently reported. Rectal carcinoma responds to preoperative chemoradiation therapy with a 10% to 15% pathologic complete response rate. Preoperative therapy offers an opportunity to reduce the positive margin rate and to reduce the APR rate. Because there is significant tumor regression with preoperative therapy, distal margins of less 1 cm are acceptable and do not result in suture line recurrence. APR rate of less than 10% is feasible and better chemotherapy with radiation therapy will reduce the APR to less than 5%.

Molecular characterization of colorectal neoplasia in translational research

OBJECTIVE

To present recent advances in the use of molecular markers in diagnosis, in prognosis, in early detection, in novel therapies, and in understanding the molecular pathogenesis of colorectal neoplasia.

DATA AND LITERATURE SOURCES

A review of studies of molecular markers in colorectal neoplasia, published in English and available on MEDLINE and BioMednet, indicates that molecular markers are being increasingly studied to predict clinical outcomes in patients with colorectal adenocarcinoma (CRC). We have used this resource, together with our published and unpublished observations at the University of Alabama at Birmingham, to provide an overview of translational research related to molecular markers in colorectal neoplasia.

CONCLUSIONS

Currently, the prognosis of patients with CRC is predicted primarily on the basis of clinicopathologic staging; however, pathologists and oncology surgeons have recently begun to investigate the use of molecular markers to diagnose and/or understand the progression of CRC. In recent years, much has been learned about the molecular events responsible for the development of CRC. Also, several studies have reported the implication of some molecular markers in metastasis and tumor aggression and their usefulness in predicting clinical outcome. In this article, we discuss the use of specific molecular markers, including tumor-associated glycoprotein 72 (TAG-72), carcinoembryonic antigen (CEA), and oncofetal tumor antigens (Lewis X and Y) in diagnosis and as targets for novel therapies, as well as the phenotypic expression of bcl-2, mucin antigens (MUC1 and MUC2), and nuclear accumulation of p53 in predicting the clinical outcome of patients with CRC. We also review the ways in which molecular markers may aid the early detection of colorectal neoplasia and promote our understanding of the earliest changes in colorectal neoplasia.

p53 and Ki-67 as predictive markers for radiosensitivity in squamous cell carcinoma of the oral cavity? an immunohistochemical and clinicopathologic study

PURPOSE

Previously published data relating the expression of p53 and Ki-67 to radiation response in head and neck cancer are conflicting. This may be due to differences in patient selection and treatment modalities. In this study of a homogenous population of patients with oral cavity cancer, Ki-67 and p53 indices were correlated with histopathologically assessed tumor regression after preoperative radiochemotherapy and longterm outcome.

METHODS AND MATERIALS

Eighty-eight patients with squamous cell carcinoma of the oral cavity and treated between September 1985 and November 1995 by preoperative radiochemotherapy and definitive surgery were included in this analysis. By immunohistochemistry (IHC) the pre-irradiation expression of p53 and of Ki-67 were analyzed and correlated with the histopathologically proven tumor regression, overall survival and local control.

RESULTS

The overall 2- and 5-year survival rates were 76.5% and 63%, the locoregional control rates were 84% and 79%, respectively. After preoperative radiochemotherapy 29 patients (33%) showed complete tumor regression (ypT(0) classification). Survival and local control rates were significantly higher for patients showing ypT(0) classification than ypT(1-4) classification (p < 0.01). This effect was independent of pretreatment tumor classification in multivariate analysis. Pre-irradiation p53 status and Ki-67 index had no influence on tumor regression and clinical outcome in these patients.

CONCLUSION

Complete tumor regression after preoperative treatment is related to an improved outcome in combined modality treatment of oral cavity cancer. The presented study could not demonstrate an influence of p53 and Ki-67 status as detected by immunohistochemical staining on survival, local control, or tumor regression after radiochemotherapy.

Adjuvant therapy for resectable rectal adenocarcinoma

The mainstay of treatment for rectal cancer over the past 100 years has been surgical resection. However, for the majority of rectal cancers treated conventionally by resection alone, locoregional recurrence is the major mode of failure. Over the past several decades, significant progress has been made in developing effective adjuvant regimens. In the United States, postoperative chemoradiation is standard treatment for T3 or node-positive patients. However, preoperative radiation with or without chemotherapy decreases local recurrence, increases sphincter preservation, and may improve survival. The purpose of this article is to review the role of adjuvant therapy in resectable rectal cancers and to update the status of ongoing randomized trials.

Preoperative staging of rectal cancer allows selection of patients for preoperative radiotherapy

BACKGROUND

Variability in rates of local recurrence following resection of rectal cancer has led to the suggestion that all patients should undergo preoperative radiotherapy. This centre employs a selective policy of radiotherapy only in patients with evidence of advanced local disease determined by preoperative staging.

METHODS

A retrospective review was carried out of 114 consecutive patients with rectal cancer. Patients were divided before operation into palliative and curative groups based on preoperative staging. Only patients in the palliative group were offered preoperative radiotherapy. Total mesorectal excision (TME) was performed for all tumours of the middle or lower rectum.

RESULTS

The perioperative mortality rate was 0.9 per cent and anastomotic dehiscence occurred in 2.8 per cent. Local recurrence developed in 4 per cent of patients in the 'curative' group and in seven of 15 of those assigned to the palliative group before operation (P < 0.01). Positive lateral resection margins were significantly associated with a risk of subsequent recurrence (ten of 13 versus three (3 per cent) of 93; P < 0.001).

CONCLUSION

Preoperative adjuvant radiotherapy can be omitted reasonably in patients in whom there is no evidence of locally advanced disease, provided that adequate surgery, incorporating TME for low tumours, is performed.

Role of adjuvant therapy in adenocarcinoma of the rectum

Combined modality therapy is the standard adjuvant therapy for selected patients with adenocarcinoma of the rectum. In the postoperative setting, the primary goal is to decrease local recurrence and improve overall survival. In the preoperative setting, adjuvant therapy has the additional potential benefit of enhancing sphincter preservation and less acute toxicity as compared with postoperative adjuvant therapy. Investigational trials are in progress to examine new systemic chemotherapeutic agents and altered radiation fractionation schemes.

Late course accelerated fractionation in radiotherapy of esophageal carcinoma

PURPOSE

To evaluate the efficacy of adding accelerated fractionation after completing two thirds of routine fractionated radiotherapy in esophageal carcinoma.

METHODS AND MATERIALS

From April 1988 to April 1990, 85 patients with histologically confirmed carcinoma of the esophagus were randomized into two groups. (1) The conventional fractionation (CF) group, received 1.8 Gy per day five times a week to a total dose of 68.4 Gy in 7-8 weeks, and (2) the late course accelerated hyperfractionated (LCAF) group which received the same schedule as the CF group during the first two thirds of the course of radiotherapy to a dose of 41.4 Gy/23 fx/4 to 5 weeks. This was then followed by accelerated hyperfractionation using reduced fields. In the LCAF portion of the radiotherapeutic course, the irradiation schedule was changed to 1.5 Gy twice a day, with an interval of 4 h between fractions, to a dose of 27 Gy/18 fx. Thus the total dose was also 68.4 Gy, the same as the CF group, but the course of radiotherapy was shorter, being only 6.4 weeks. The same Cobalt 60 teletherapy unit was used to treat all the cases.

RESULTS

The 5 year actuarial survival and disease-free survival rates in the LCAF group were 34% and 42%, as compared to 15% and 15% respectively in the CF group, all statistically significant. Better local control was seen in the LCAF group than in the CF group, the 5 year control rates being 55% versus 21% (P = 0.003). The acute reactions were increased but acceptable in the LCAF patients, the radiation treatments could be completed without any breaks. The late reactions as observed after 5 years were not increased in comparison with the CF patients.

CONCLUSIONS

The results from this study show that the late course accelerated hyperfractionated radiotherapy regime can improve results in esophageal carcinoma, with acceptable acute reactions as compared to conventional radiotherapy.

Prognostic markers in rectal carcinoma

Guidelines from two major organizations have recently supported the use of only the serological marker carcinoembryonic antigen (CEA) for the prognostication and monitoring of patients with colorectal carcinoma. However, in view of the exciting advances made recently in elucidating the molecular and cellular biology of adenocarcinoma of the rectum, the molecules that transform the well-ordered normal rectal epithelium into an invasive adenocarcinoma may yield information about the ultimate behavior of that cancer. Consequently, assessing the expression of molecules within a primary cancer may predict the probability of regional and distant metastasis, response to therapy, and outcome. This review analyzes the current state of intratumoral expression of several molecular markers for the management of rectal cancer and evaluates their potential for defining which patients may undergo rectal sphincter preservation and need adjuvant therapy.

Apparent lack of prognostic value of MIB-1 index in anal carcinomas treated by radiotherapy

This study was conducted to investigate the influence of Mib-1 index on outcome in 55 patients with T1-4 anal carcinomas treated radically by radiotherapy (RT) alone (24) or by concomitant chemo-radiotherapy (31). Median follow-up for surviving patients was 94 months (range 17-179 months). Tissue materials were obtained from pretreatment biopsies. A modified immunoperoxidase technique consisting of microwave heating of routinely processed material was employed using the Mib-1 antibody (Immunotech, 1:50). The median Mib-1 index for all patients was 53% (range 18-96%). Subgroups of patients with high vs low Mib-1 indices (separated by the median value) had statistically similar outcomes regarding 5-year overall survival (64% vs 65% P = 0.7), locoregional control (77% vs 69%, P = 0.5) and disease-free survival (73% vs 66%, P = 0.5). Moreover, no significant association was found between mean Mib-1 indices and various clinicopathological parameters studied (age, sex, circumferential tumour extent, T-stage, N-stage and histological type). In conclusion, Mib-1 index failed to predict the outcome of patients with anal carcinomas treated conservatively by radiotherapy with or without chemotherapy. It is noteworthy that the median Mib-1 index observed in anal carcinomas in this study was among the highest yet reported for cancers of epithelial origin.

Clinical and molecular prognostic factors in sphincter-preserving surgery for rectal cancer

As many as a third of patients with rectal cancers may be candidates for sphincter preservation surgery. The goal of the conservative management of adenocarcinoma of the distal rectum is to preserve rectal sphincter function without sacrificing local tumor control. To achieve this goal, a combined modality approach is necessary because multimodality therapy for more advanced disease has improved both local control and survival. Candidates for local excision are those with adenocarcinomas with a maximal diameter of less than 4 cm, mobile, and not poorly differentiated or mucinous and within 10 cm of the anal verge--usually within 6 cm. These criteria should be defined objectively by biopsy combined with state-of-the-art endorectal imaging. Newer molecular markers that are associated with prognosis and response to therapy may also be important for assessing prognosis, probability of local recurrence, and whether conservative treatment is appropriate. Patients with T0-3 N0 lesions meeting these standard clinicopathologic criteria have been treated successfully with wide local excision combined with chemotherapy and radiotherapy. Patients with larger or more advanced lesions may undergo low anterior resection with coloanal anastomosis. After resection, radiotherapy to at least 45 to 50 Gy is delivered to the pelvis and tumor bed often with concomitant chemotherapy. The overall rate of local failure in prospective single-institution trials in which local excision is performed with postoperative chemoradiotherapy has been 5% for T1 lesions, 7% for T2 lesions and 24% for T3 lesions. Although single-institution studies have supported the concept of conservative therapy, the safety and efficacy of this approach must still be confirmed in a multicenter, prospective trial, such as that underway in several of the cooperative oncology groups, before it may be considered a standard of practice.

Changes in tumor proliferation of rectal cancer induced by preoperative 5-fluorouracil and irradiation

PURPOSE

This study examines the effect of 5-fluorouracil administration during preoperative irradiation on rectal cancer tumor proliferation.

PATIENTS AND METHODS

One hundred and fifty-three patients with locally advanced rectal cancer received 45 to 50 Gy of preoperative irradiation with (103 patients) and without (50 patients) concurrent 5-fluorouracil, followed by surgery. Pretreatment tumor biopsies and postirradiation surgical specimens were scored for proliferative activity by assaying the extent of Ki-67 and proliferating cell nuclear antigen immunostaining and the number of mitoses per ten high-powered fields. Postirradiation specimens were also assessed for downstaging.

RESULTS

Although 5-fluorouracil did not improve downstaging rates, marked decreases in the activity of all three markers of proliferation (mitotic counts, Ki-67, and proliferating cell nuclear antigen immunostaining) were seen in rectal cancers of patients receiving the drug. No significant decreases were noted in patients undergoing irradiation only.

CONCLUSION

The addition of 5-fluorouracil to preoperative irradiation resulted in a more complete inactivation of the proliferating population. Frequency of downstaging, however, was unaffected. Thus, the quiescent cell population appears to represent a substantial barrier to further downstaging. New treatment strategies should be aimed at controlled recruitment of quiescent tumor cells at the time of irradiation.

Sphincter preservation in rectal cancer. Preoperative radiation therapy followed by low anterior resection with coloanal anastomosis

The advantage of preoperative therapy in patients with clinically resectable transmural rectal cancer is to increase sphincter preservation while obtaining a high likelihood of local control. In patients who undergo a prospective clinical assessment and are declared to require an abdominoperineal resection, preoperative radiation therapy, either alone or when combined with chemotherapy, allows approximately 80% of patients to undergo a low anterior resection with or without colo anal anastomosis. The majority have good-to-excellent sphincter function. This conservative approach may be an alternative to an abdominoperineal resection in selected patients.

Aggressive multimodality treatment for locally advanced irresectable rectal cancer

BACKGROUND

Local failure rates are high for locally irresectable primary or recurrent colorectal cancer, even when chemoradiation therapy is employed.

AIM

This review evaluates evidence supporting aggressive preoperative chemoradiation followed by maximal surgical resection and intraoperative radiation therapy to achieve disease control and cure for patients with locally advanced irresectable primary or recurrent rectal cancer.

RESULTS

A 5-year survival rate of 42 per cent with a central failure rate of 2 per cent may be achieved in patients with locally irresectable primary rectal cancer. In patients with locally recurrent disease, these values at 5 years are 18 and 28 per cent respectively. The 5-year incidence of distant metastasis remains high, affecting 64 per cent of patients with primary cancer and 75 per cent of those with recurrent cancer.

CONCLUSION

A disease-free surgical resection margin remains paramount to achieve cure. Encouraging trends exist, however, for further evaluation of multimodality therapy as a means of reducing local recurrence of disease.