A histopathological assessment of the response of rectal adenocarcinoma to combination chemo-radiotherapy: relationship to apoptotic activity, p53 and bcl-2 expression

Overexpression of MLPH in Rectal Cancer Patients Correlates with a Poorer Response to Preoperative Chemoradiotherapy and Reduced Patient Survival

Data mining of a public transcriptomic rectal cancer dataset (GSE35452) from the Gene Expression Omnibus, National Center for Biotechnology Information identified the melanophilin (MLPH) gene as the most significant intracellular protein transport-related gene (GO:0006886) associated with a poor response to preoperative chemoradiation. An MLPH immunostain was performed on biopsy specimens from 172 rectal cancer patients receiving preoperative chemoradiation; samples were divided into high- and low-expression groups by H-scores. Subsequently, the correlations between MLPH expression and clinicopathologic features, tumor regression grade, disease-specific survival (DSS), local recurrence-free survival (LRFS), and metastasis-free survival (MeFS) were analyzed. MLPH expression was significantly associated with CEA level (p = 0.001), pre-treatment tumor status (p = 0.022), post-treatment tumor status (p < 0.001), post-treatment nodal status (p < 0.001), vascular invasion (p = 0.028), and tumor regression grade (p < 0.001). After uni- and multi-variable analysis of five-year survival, MLPH expression was still associated with lower DSS (hazard ratio (HR), 10.110; 95% confidence interval (CI), 2.178–46.920; p = 0.003) and MeFS (HR, 5.621; 95% CI, 1.762–17.931; p = 0.004). In conclusion, identifying MLPH expression could help to predict the response to chemoradiation and survival, and aid in personal therapeutic modification.

Radiotherapy and Oral Capecitabine in the Preoperative Treatment of Patients with Rectal Cancer: Rationale, Preliminary Results and Perspectives

Preoperative radiotherapy alone or combined with chemotherapy increases the chances of tumor downstaging and down-sizing and facilitates sphincter-sparing surgical procedures, thereby improving survival and quality of life. Though several innovative agents are being investigated in combination with radiotherapy, 5-fluorouracil in continuous infusion remains the common schedule used in the preoperative chemoradiation setting. However, the protracted venous infusion of 5-fluorouracil requires specialized pumps and long-term venous access, which makes patients susceptible to infections or thrombosis. To overcome the 5-fluorouracil infusion-related problems, oral 5-fluorouracil precursors and inhibitors of 5-fluorouracil degradation have been developed and explored. These include oral fluoropyrimidines such as tegafur (ftora-fur), uracil plus tegafur (UFT), S-1, eniluracil and the oral carbamate capecitabine. Phase I trials have demonstrated the feasibility of the capecitabine-radiotherapy combination with respect to the bolus or infusion 5-fluorouracil-radiation approach and have defined the optimal dose of capecitabine during radiotherapy (825 mg/m2/day through a bid administration). Severe hand-foot syndrome occurred in 7-15% of patients, representing the most commonly observed toxicity. It is noteworthy that severe diarrhea with capecitabine during radiotherapy was not common. Leukopenia frequently occurred but was mild and reversible. Phase II trials, although limited in number, have evidenced a high probability of pathological complete response (up to 31%) with capecitabine and radiation, with an increased probability of sphincter-sparing surgical procedures. Although it is too early to assess whether oral capecitabine will be able to replace iv 5-fluorouracil in combination with preoperative radiotherapy, the NSABP will address this question in a large randomized trial. Finally, phase I-II trials evaluating escalating doses of capecitabine associated with oxaliplatin or irinotecan with radiotherapy are being carried out to assess the maximum-dose tolerance and efficacy in the preoperative setting. It is likely that these new chemoradiation associations might increase rectal cancer clearance, hopefully without increasing toxicity.

Isobavachalcone inhibits the proliferation and invasion of tongue squamous cell carcinoma cells

Isobavachalcone (2′,4′,4-trihydroxy-3′-[3′-methylbut-3′-ethyl] chalcone or IBC) exhibits anticancer activities in a number of types of cancer cell. However, its role in tongue squamous cell carcinoma (TSCC) cells remains unclear. The aim of the present study was to investigate the biological effect of IBC in TSCC Tca8113 cells. The function of IBC on Tca8113 cell apoptosis and apoptosis-associated signaling pathways was determined using an MTT assay, morphological staining, annexin V-propidium iodide (PI) staining and Western blot analysis. The effects of IBC on Tca8113 cell migration, invasion and relative protein expression were confirmed using wound healing analysis, Transwell invasion analysis and Western blot analysis, respectively. The results of the MTT assay and annexin V-PI staining indicated that IBC is able to significantly inhibit proliferation and induce apoptosis of Tca8113 cells in vitro. IBC treatment resulted in typical apoptotic morphology of nuclear fragmentation and apoptotic bodies in Tca8113 cells. Western blot analysis further demonstrated that IBC caused downregulation of the expression of B-cell lymphoma 2 (Bcl-2) protein, upregulation of the expression of Bcl-2-associated X protein (Bax), activation of caspases, and dephosphorylation of protein kinase B (Akt) and extracellular-signal-regulated kinase (ERK) proteins in a concentration- and time-dependent manner. The results of the present study suggest that IBC induces apoptosis in Tca8113 cells and that the induction may be associated with the activation of Bcl-2, Bax and caspase-3, and the inactivation of Akt and ERK. Furthermore, IBC inhibited migration and invasion of Tca8113 cells in vitro by downregulating matrix metalloproteinase (MMP)-2 and MMP-9 protein expression. The results of the present study indicate that IBC may be a potential anticancer drug for the treatment of TSCC.

Predicting pathological complete response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer: a systematic review

AIM

Approximately 20% of patients treated with neoadjuvant chemoradiotherapy (nCRT) for locally advanced rectal cancer achieve a pathological complete response (pCR) while the remainder derive the benefit of improved local control and downstaging and a small proportion show a minimal response. The ability to predict which patients will benefit would allow for improved patient stratification directing therapy to those who are likely to achieve a good response, thereby avoiding ineffective treatment in those unlikely to benefit.

METHOD

A systematic review of the English language literature was conducted to identify pathological factors, imaging modalities and molecular factors that predict pCR following chemoradiotherapy. PubMed, MEDLINE and Cochrane Database searches were conducted with the following keywords and MeSH search terms: 'rectal neoplasm', 'response', 'neoadjuvant', 'preoperative chemoradiation', 'tumor response'. After review of title and abstracts, 85 articles addressing the prediction of pCR were selected.

RESULTS

Clear methods to predict pCR before chemoradiotherapy have not been defined. Clinical and radiological features of the primary cancer have limited ability to predict response. Molecular profiling holds the greatest potential to predict pCR but adoption of this technology will require greater concordance between cohorts for the biomarkers currently under investigation.

CONCLUSION

At present no robust markers of the prediction of pCR have been identified and the topic remains an area for future research. This review critically evaluates existing literature providing an overview of the methods currently available to predict pCR to nCRT for locally advanced rectal cancer. The review also provides a comprehensive comparison of the accuracy of each modality.

Genotypic characteristics of resistant tumors to pre-operative ionizing radiation in rectal cancer

Due to a wide range of clinical response in patients undergoing neo-adjuvant chemoradiation for rectal cancer it is essential to understand molecular factors that lead to the broad response observed in patients receiving the same form of treatment. Despite extensive research in this field, the exact mechanisms still remain elusive. Data raging from DNA-repair to specific molecules leading to cell survival as well as resistance to apoptosis have been investigated. Individually, or in combination, there is no single pathway that has become clinically applicable to date. In the following review, we describe the current status of various pathways that might lead to resistance to the therapeutic applications of ionizing radiation in rectal cancer.

Gender-related differences in pathological and clinical tumor response based on immunohistochemical proteins expression in rectal cancer patients treated with short course of preoperative radiotherapy

BACKGROUND

Prognostic value of pretreatment expression of proteins in rectal cancer for early pathological tumor response (pTR), clinical tumor response (CTR) to preoperative radiotherapy (RT), and the potential difference between these parameters depending on patient gender is not established.

MATERIAL AND METHODS

One hundred eleven patients were treated with short preoperative course of RT (SCRT) with 5 Gy dose per fraction during 5 days, followed by surgery 3 to 53 days (mean, 21 days) later. Expression of CD34, Ki-67, GLUT-1, Ku70, BCL-2, and P53 proteins was assessed immunohistochemically.

RESULTS

There were 76 men and 35 women. There were 27, 69, and 15 clinical tumor-node-metastasis (cTNM) tumor stages I, II, and III, respectively. Significant differences in Ki-67, GLUT-1, Ku 70, and BCL-2 expressions between male and female tumors were observed for pathological TNM (pTNM) stage and grade. Association between proteins expression and pTNM, pTR, and CTR was analyzed separately for short (≤15 days) and long (>15 days) break between RT and surgery and males and female patients. For SCRT with short break, no protein was significantly related to pTNM; for pTR, higher Ki-67 and lower BCL-2 expression were correlated with pTR. In the male subgroup, BCL-2 overexpression was predictive. For SCRT with long break, none of the proteins was predictive for pTR, but Ki-67, Ku70 (in female subgroup), and BCL-2 expressions were positively correlated with pTNM. BCL-2 overexpression was associated with CTR in the females only.

CONCLUSION

In SCRT, long break in the treatment should be avoided because correlation between Ki-67, KU70, and BCL-2 expressions and pTNM after RT might indicate tumor progression.

Role of activating transcription factor 3 (ATF3) in endoplasmic reticulum (ER) stress-induced sensitization of p53-deficient human colon cancer cells to tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis through up-regulation of death receptor 5 (DR5) by zerumbone and celecoxib

Death receptor 5 (DR5) is a death domain-containing transmembrane receptor that triggers cell death upon binding to its ligand, TNF-related apoptosis-inducing ligand (TRAIL), and a combination of TRAIL and agents that increase the expression of DR5 is expected to be a novel anticancer therapy. In this report, we demonstrate that the stress response gene ATF3 is required for endoplasmic reticulum stress-mediated DR5 induction upon zerumbone (ZER) and celecoxib (CCB) in human p53-deficient colorectal cancer cells. Both agents activated PERK-eIF2α kinases and induced the expression of activating transcription factor 4 (ATF4)-CCAAT enhancer-binding protein (C/EBP) homologous protein, which were remarkably suppressed by reactive oxygen species scavengers. In the absence of ATF3, the induction of DR5 mRNA and protein was abrogated significantly, and this was associated with reduced cell death by cotreatment of TRAIL with ZER or CCB. By contrast, exogenous expression of ATF3 caused a more rapid and elevated expression of DR5, resulting in enhanced sensitivity to apoptotic cell death by TRAIL/ZER or TRAIL/CCB. A reporter assay demonstrated that at least two ATF/cAMP response element motifs as well as C/EBP homologous protein motif at the proximal region of the human DR5 gene promoter were required for ZER-induced DR5 gene transcription. Taken together, our results provide novel insights into the role of ATF3 as an essential transcription factor for p53-independent DR5 induction upon both ZER and CCB treatment, and this may be a useful biomarker for TRAIL-based anticancer therapy.

Molecular markers for targeted neoadjuvant rectal cancer therapy

SUMMARY Neoadjuvant chemoradiotherapy is the standard of care for locally advanced rectal cancer. While neoadjuvant chemoradiation has been demonstrated to improve oncological outcomes, there is a wide spectrum of responses to therapy. The ability to predict who will respond favorably or unfavorably to neoadjuvant therapy could prevent unnecessary morbidity and potentially lead to novel therapeutic targets. A number of individual biomarkers and multigene signatures have been investigated as potential means of predicting response to neoadjuvant chemoradiation. While promising, none of these predictive biomarkers have yet been introduced clinically. This review summarizes both individual and multigene biomarkers for rectal cancer response to neoadjuvant chemoradiation.

P53 status as a predictive biomarker for patients receiving neoadjuvant radiation-based treatment: a meta-analysis in rectal cancer

Background

Numerous studies have yielded inconsistent results regarding the relationship between p53 status and the response to neoadjuvant radiation-based therapy in patients with rectal cancer. We conducted a meta-analysis to clarify the relationship between p53 status and response to radiation-based therapy in rectal cancer.

Methods/Findings

A total of 30 previously published eligible studies including 1,830 cases were identified and included in this meta-analysis. Wild-type form of p53 status (low expression of p53 protein and/or wild-type p53 gene) was associated with pathologic response in rectal cancer patients who received neoadjuvant radiation-based therapy (good response: risk ratio [RR] = 1.30; 95% confidence intervals [CI] = 1.14–1.49; p<0.001; complete response RR = 1.65; 95% CI = 1.19–2.30; p = 0.003; poor response RR = 0.85; 95% CI = 0.75–0.96; p = 0.007). In further stratified analyses, this association remained for sub-groups of good and poor response in neoadjuvant radiotherapy (RT) setting, good and complete response in chemoradiotherapy (CRT) setting. And the association between response and the presence of p53 gene mutations was stronger than that between response and protein positivity.

Conclusion

The results of the present meta-analysis indicate that P53 status is a predictive factor for response in rectal cancer patient undergoing neoadjuvant radiation-based therapy.

Survivin expression can predict the effect of chemoradiotherapy for advanced lower rectal cancer

BACKGROUND

Chemoradiotherapy (CRT) has been used to improve local control and survival in patients with advanced rectal carcinoma. However, a significant proportion of patients show poor response to adjuvant CRT. We thus investigated the usefulness of survivin expression as a predictive marker of the CRT response and its characteristics.

METHODS

Forty-three patients with lower rectal cancer who underwent CRT were investigated. All patients received preoperative CRT consisting of TS-1 concurrent with 40 Gy of pelvic irradiation followed by curative resection. The relationship between clinical response, or pathological response, and the expression of survivin of pre-CRT biopsy specimens was evaluated by immunohistochemistry and compared with post-CRT expression.

RESULTS

Positive expression of survivin was observed in 26 of 43 patients (60%) in pre-CRT specimens. Survivin was positively expressed in 77% of stable disease cases, and 43% of partial response (p < 0.05). Regarding the correlation between pathological response and survivin expression, positive expression of survivin was recognized in 75% (18 of 24) of Grade 0 + 1 cases, 50% (7 of 14) of Grade 2 cases, and 20% (1 of 5) of Grade 3 cases. A reverse correlation was recognized between pathological responses and survivin expression (p < 0.05). There were differences in the tumor differentiation between the survivin-positive group and the negative group (p < 0.05). The expression concordance rate was 66% between pre- and post-CRT tissues. In post-CRT tissues, nuclear survivin expression disappeared completely and cytoplasmic expression increased, especially in responder cases.

CONCLUSION

Survivin expression in biopsy could be an important predictive factor of preoperative CRT response.

XIAP as a radioresistance factor and prognostic marker for radiotherapy in human rectal adenocarcinoma

A differential responsiveness of patients to ionizing radiation is observed after preoperative radiotherapy for rectal adenocarcinoma that might be related, in part, to an apoptosis defect. To establish if proteins of the apoptotic cascades [pro-apoptotic: active caspase 3, 8, and 9 and DIABLO (direct inhibitor of apoptosis-binding protein with low pI); anti-apoptotic: XIAP (X-linked inhibitor of apoptosis)] are involved, we analyzed their profile in radioresistant (SW480) and radiosensitive (SW48) human colorectal cell lines. We demonstrated that, after irradiation, the SW48 cells increased the expression of the pro-apoptotic proteins, whereas the SW480 cells increased the expression of the anti-apoptotic protein XIAP. Moreover, XIAP knockdown in SW480 cells enhanced the basal and radiation-induced apoptotic index; the propensity of the SW480 cells to undergo apoptosis after radiation was higher compared with SW48 cells. In a translational study of 38 patients with rectal carcinoma, we analyzed the apoptotic profile for tumor and noncancerous tissue for each biopsy specimen using IHC. According to their response to preoperative radiotherapy, patients were classified into two groups: responsive and nonresponsive. Although no difference in expression of caspase 3, 8, or 9 was observed in the tumor/normal tissue ratio between responsive and nonresponsive patients, the ratio decreased for DIABLO and increased for XIAP. In conclusion, inhibition of XIAP rescues cellular radiosensitivity and both DIABLO and XIAP might be potential predictive markers of radiation responsiveness in rectal adenocarcinoma.

Key role of ATF3 in p53-dependent DR5 induction upon DNA damage of human colon cancer cells

Stress response gene ATF3 is one of the p53 target genes and has a tumor suppressor role in cancer. However, the biological role of p53-ATF3 pathway is not well understood. Death receptor 5 (DR5) is a death domain-containing transmembrane receptor that triggers cell death upon binding to its ligand TRAIL (tumor necrosis factor-related apoptosis-inducing ligand), and a combination of TRAIL and agents that increase the expression of DR5 is expected as a novel anticancer therapy. In this report, we demonstrate that ATF3 is required for efficient DR5 induction upon DNA damage by camptothecin (CPT) in colorectal cancer cells. In the absence of ATF3, induction of DR5 messenger RNA and protein is remarkably abrogated, and this is associated with reduced cell death by TRAIL and CPT. By contrast, exogenous expression of ATF3 causes more rapid and elevated expression of DR5, resulting in enhanced sensitivity to apoptotic cell death by TRAIL/CPT. Reporter assay and DNA affinity precipitation assay demonstrate that at least three ATF/CRE motifs at the proximal promoter of the human DR5 gene are involved in the activation of DNA damage-induced DR5 gene transcription. Furthermore, ATF3 is shown to interact with p53 to form a complex on the DR5 gene by Re-chromatin immunoprecipitation assay. Taken together, our results provide a novel insight into the role of ATF3 as an essential co-transcription factor for p53 upon DNA damage, and this may represent a useful biomarker for TRAIL-based anticancer therapy.

Impact of tumor response on survival after radiochemotherapy in locally advanced rectal carcinoma

In locally advanced rectal adenocarcinoma, preoperative radiochemotherapy induces tumor response. The impact of pathologic tumor response on survival is still debated because of the numerous distinct tumor-response gradings available in the literature and the lack of standardized pathologic approach. The objective of this work was to study the impact of tumor response on survival, according to the 4 main tumor-response gradings available in the literature in locally advanced rectal adenocarcinoma after preoperative radiochemotherapy. From 1995 to 2004, 292 consecutive patients with cT3-T4 and/or N+ rectal adenocarcinoma were enrolled. Tumor response was evaluated according to ypTN-response gradings (downstaging: ypT0-2 N0 and complete pathologic response: ypT0 N0) and cellular-response gradings (ie, Mandard et al's and Rodel et al's gradings). The impact of tumor-response gradings and of different clinicopathologic variables on 5-year disease-free and overall survival were studied by univariate and multivariate analyses. We found that all tumor-response gradings were associated with survival. However, multivariate analysis showed that downstaging was the only tumor-response grading that influenced survival independently. In the subgroup of stage II patients (n=99), we also observed no difference on both 5-year disease-free and overall survival between low and high responders according to cellular response. In conclusion, in our experience, downstaging is the only tumor-response grading that influenced survival independently in locally advanced rectal adenocarcinomas. Cellular-response gradings had no impact on survival even in stage II patients.

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.

Chromosomal copy number changes of locally advanced rectal cancers treated with preoperative chemoradiotherapy

Standard treatment of rectal cancer patients comprises preoperative chemoradiotherapy followed by radical surgery. However, clinicians are faced with the problem that response rates vary from one individual to another. Predictive biomarkers would therefore be helpful. To identify genomic imbalances that might assist in stratifying tumors into responsive or nonresponsive categories, we used metaphase comparative genomic hybridization to prospectively analyze pretherapeutic biopsies from 42 patients with locally advanced rectal cancers. These patients were subsequently treated with 5-fluorouracil-based preoperative chemoradiotherapy. Based on downsizing of the T-category, 21 rectal cancers were later classified as responsive, while the other 21 were nonresponsive. Comparing these two groups, we could show that gains of chromosomal regions 7q32 approximately q36 and 7q11 approximately q31, as well as amplifications of 20q11 approximately q13, were significantly associated with responsiveness to preoperative chemoradiotherapy (P<0.05). However, the probability of detecting these copy number changes by chance is high (P=0.21). Our primary results suggest that pretherapeutic evaluation of chromosomal copy number changes may be of value for response prediction of rectal cancers to preoperative chemoradiotherapy. This will require validation in a larger cohort of patients.

Biomarkers for response to neoadjuvant chemoradiation for rectal cancer

Locally advanced rectal cancer (LARC) is currently treated with neoadjuvant chemoradiation. Although approximately 45% of patients respond to neoadjuvant therapy with T-level downstaging, there is no effective method of predicting which patients will respond. Molecular biomarkers have been investigated for their ability to predict outcome in LARC treated with neoadjuvant chemotherapy and radiation. A literature search using PubMed resulted in the initial assessment of 1,204 articles. Articles addressing the ability of a biomarker to predict outcome for LARC treated with neoadjuvant chemotherapy and radiation were included. Six biomarkers met the criteria for review: p53, epidermal growth factor receptor (EGFR), thymidylate synthase, Ki-67, p21, and bcl-2/bax. On the basis of composite data, p53 is unlikely to have utility as a predictor of response. Epidermal growth factor receptor has shown promise as a predictor when quantitatively evaluated in pretreatment biopsies or when EGFR polymorphisms are evaluated in germline DNA. Thymidylate synthase, when evaluated for polymorphisms in germline DNA, is promising as a predictive biomarker. Ki-67 and bcl-2 are not useful in predicting outcome. p21 needs to be further evaluated to determine its usefulness in predicting outcome. Bax requires more investigation to determine its usefulness. Epidermal growth factor receptor, thymidylate synthase, and p21 should be evaluated in larger prospective clinical trials for their ability to guide preoperative therapy choices in LARC.

Expression of Bcl-2 in olfactory neuroblastoma and its association with chemotherapy and survival

OBJECTIVE

This study aimed to identify the prognostic value of tumor markers in olfactory neuroblastoma (ONB).

STUDY DESIGN AND SETTING

Seventeen patients with ONB (23 tumor specimens) were included. Each specimen was studied for bcl-2, p53, MIC-2 by immunohistochemistry and for N-myc by chromogenic in situ hybridization.

RESULTS

Twelve (70%) of 17 patients and 15 (65%) of 23 specimens showed positive reactivity for bcl-2. Of seven patients who were treated with neoadjuvant chemotherapy, one patient with diffuse bcl-2 expression achieved complete remission. Another patient without bcl-2 expression had no response to chemotherapy. Five patients who showed partial positivity achieved partial remission. Survival and bcl-2 expression tended to correlate, but it was not statistically significant (P = 0.06). All of the ONB specimens were negative for N-myc. Positive immunoreactivity for MIC-2 or p53 was found only in one specimen.

CONCLUSION

Bcl-2 expression was commonly found in ONB and the immunoreactivity for bcl-2 might predict response to neoadjuvant chemotherapy. In addition, Bcl-2 expression tended to be associated with worse survival.

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.

Phase II study of weekly intravenous oxaliplatin combined with oral daily capecitabine and radiotherapy with biologic correlates in neoadjuvant treatment of rectal adenocarcinoma

PURPOSE

To evaluate the efficacy of a combination of capecitabine, oxaliplatin, and radiotherapy (RT) in the neoadjuvant treatment of Stage II and III rectal cancers.

METHODS

Capecitabine was given at 725 mg/m(2) orally twice daily Monday through Friday concurrently with RT. Oxaliplatin was given intravenously at 50 mg/m(2) once weekly five times starting the first day of RT. The radiation dose was 50.4 Gy in 28 fractions (1.8 Gy/fraction), five fractions weekly. Endorectal tumor biopsies were obtained before treatment and on the third day of treatment to explore the effects of treatment on thymidine phosphorylase, thymidylate synthase, excision repair cross-complementing rodent repair deficiency complementation group 1 (ERCC1), and apoptosis.

RESULTS

A total of 25 patients were enrolled in this study; 6 patients (24%) had a complete pathologic response. T-downstaging occurred in 52% of patients, and N-downstaging occurred in 53%. Grade 3 diarrhea was the most common Grade 3-4 toxicity, occurring in 20% of patients. Only 2 patients experienced disease recurrence, with a median of 20 months of follow-up. Thymidylate synthase, thymidine phosphorylase, ERCC1, and apoptosis did not vary significantly between the pretreatment and Day 3 tumor biopsies, nor did they predict for T-downstaging or a complete pathologic response.

CONCLUSION

Capecitabine at 725 mg/m(2) orally twice daily, oxaliplatin 50 mg/m(2)/wk, and RT at 50.4 Gy is an effective neoadjuvant combination for Stage II and III rectal cancer and results in a greater rate of complete pathologic responses than historically shown in fluoropyrimidine plus RT controls.

Survivin antisense oligonucleotides effectively radiosensitize colorectal cancer cells in both tissue culture and murine xenograft models

PURPOSE

Survivin shows a radiation resistance factor in colorectal cancer. In the present study, we determined whether survivin messenger RNA levels in patients with rectal cancer predict tumor response after neoadjuvant radiochemotherapy and whether inhibition of survivin by the use of antisense oligonucleotides (ASOs) enhances radiation responses.

METHODS AND MATERIALS

SW480 colorectal carcinoma cells were transfected with survivin ASO (LY2181308) and irradiated with doses ranging from 0-8 Gy. Survivin expression, cell-cycle distribution, gammaH2AX fluorescence, and induction of apoptosis were monitored by means of immunoblotting, flow cytometry, and caspase 3/7 activity. Clonogenic survival was determined by using a colony-forming assay. An SW480 xenograft model was used to investigate the effect of survivin attenuation and irradiation on tumor growth. Furthermore, survivin messenger RNA levels were studied in patient biopsy specimens by using Affymetrix microarray analysis.

RESULTS

In the translational study of 20 patients with rectal cancer, increased survivin levels were associated with significantly greater risk of local tumor recurrence (p = 0.009). Treatment of SW480 cells with survivin ASOs and irradiation resulted in an increased percentage of apoptotic cells, caspase 3/7 activity, fraction of cells in the G(2)/M phase, and H2AX phosphorylation. Clonogenic survival decreased compared with control-treated cells. Furthermore, treatment of SW480 xenografts with survivin ASOs and irradiation resulted in a significant delay in tumor growth.

CONCLUSION

Survivin appears to be a molecular biomarker in patients with rectal cancer. Furthermore, in vitro and in vivo data suggest a potential role of survivin as a molecular target to improve treatment response to radiotherapy in patients with rectal cancer.

Circumferential margin involvement is the crucial prognostic factor after multimodality treatment in patients with locally advanced rectal carcinoma

PURPOSE

After preoperative (radio)chemotherapy, histologic determinants for prognostication have changed. It is unclear which variables, including assessment of tumor regression, are the best indicators for local recurrence and survival.

EXPERIMENTAL DESIGN

A series of 201 patients with locally advanced rectal cancer (cT3/T4, M0) presenting with an involved or at least threatened circumferential margin (CRM) on preoperative imaging (<2 mm) were evaluated using standard histopathologic variables and four different histologic regression systems. All patients received neoadjuvant radiochemotherapy or radiotherapy. The prognostic value of all factors was tested with univariate survival analysis of time to local recurrence and overall survival.

RESULTS

Local recurrence occurred in only 8% of the patients with a free CRM compared with 43% in case of CRM involvement (P < 0.0001). None of the four regression systems were associated with prognosis, not even when corrected for CRM status. However, we did observe a higher degree of tumor regression after radiochemotherapy compared with radiotherapy (P < 0.001). Absence of tumor regression was associated with increasing invasion depth and a positive CRM (P = 0.02 and 0.03, respectively).

CONCLUSIONS

Assessment of CRM involvement is the most important pathologic variable after radiochemotherapy. Although tumor regression increases the chance on a free CRM, in cases with positive resection margins prognosis is poor irrespective of the degree of therapy-induced regression.

Survivin, p53, and Ki-67 as predictors of histopathologic response in locally advanced rectal cancer treated with preoperative chemoradiotherapy

PURPOSE

The ability to predict response to chemoradiotherapy before the treatment may allow protecting poorly responding patients from the side effects of neoadjuvant treatment. Several molecular markers have been proposed to radio and chemosensitivity of rectal cancer. In this study, from pre-irradiation tumor biopsies, a novel and promising candidate factor survivin, and p53 and Ki-67 were assessed as predictors of response to preoperative chemoradiotherapy.

MATERIALS AND METHODS

Expression of each marker was evaluated by immunohistochemistry on pretreatment biopsies from 37 patients having rectal cancer treated with preoperative chemoradiotherapy and curative surgery. Treatment response was assessed histopathologically in the resected surgical specimen.

RESULTS

There was no correlation between expression of p53, Ki-67, and survivin with response to preoperative chemoradiotherapy and prognosis.

CONCLUSIONS

Our data suggest that these molecular markers are not helpful to identify patients who would have benefit from neoadjuvant treatment of rectal cancer. Further investigations are necessary to select patients for preoperative treatment based on analysis of the preoperative biopsies.

Metabolic functional imaging for tumor radiosensitivity monitoring

Assessing tumor radiosensitivity before and during radiation therapy can be a crucial element in decision-making with regard to treatment. However, no known non-invasive test is available at present, which allows for a reliable evaluation of the radiosensitivity of a tissue subjected to radiotherapy. Among tests being evaluated, positron emission tomography (PET) is considered to be a promising method. The purpose of this review is to identify the tests and research paths that have recently been explored for the evaluation of tumor response to treatment after isotopic labeling revealed by nuclear imaging. The majority of the explored methodologies are based on the indirect evaluation of the radiosensitivity by cell proliferation or apoptosis, tissue oxygenation or hypoxia, intrinsic radiosensitivity of clonogenic cells, tumor metabolism and angiogenesis. The development of such methods would permit the adoption of a therapeutic regimen with respect to a given radiosensitivity of a tissue. Therefore, a given therapeutic strategy could be readjusted (by associating, for instance, a radiosensitizer of hypoxic cells) or even modified if it proved to be inadequate or when it presents an unfavorable cost-effectiveness ratio. We present here a critical review of the radiotracers revealed by nuclear imaging that are developed for radiosensitivity monitoring.

A Phase I study of weekly intravenous oxaliplatin in combination with oral daily capecitabine and radiation therapy in the neoadjuvant treatment of rectal adenocarcinoma

PURPOSE

We conducted a Phase I study to determine the maximum tolerated dose (MTD) of neoadjuvant capecitabine, oxaliplatin, and radiation therapy (RT) in Stage II to III rectal adenocarcinoma.

METHODS AND MATERIALS

Capecitabine was given orally twice daily Monday through Friday concurrently with RT. Oxaliplatin was given i.v. once weekly x 5 (for 5 weeks) starting the first day of RT. RT was given daily except on weekends and holidays at 1.8 Gy per fraction x 28. Escalation for capecitabine or oxaliplatin was to occur in cohorts of three patients until the maximum tolerated dose (MTD) was defined. Endorectal tumor biopsy samples were obtained before and on Day 3 of treatment to explore the effects of treatment on thymidine phosphorylase, thymidylate synthase, dihydropyrimidine dehydrogenase, DNA repair, and apoptosis.

RESULTS

Twelve patients were enrolled on this study. Two of 6 patients at dose level (DL) 1 (capecitabine 825 mg/m2 orally (p.o.) given twice daily (b.i.d.); oxaliplatin 50 mg/m2/week) had a dose-limiting diarrhea. One of 6 patients at DL (-)1 (capecitabine 725 mg/m2 p.o., b.i.d.; oxaliplatin 50 mg/m2/week) experienced-dose-limiting diarrhea. Three of 11 patients who underwent resection had a complete pathologic response. No remarkable variations in rectal tumor biologic endpoints were noted on Day 3 of treatment in comparison to baseline. However, a higher apotosis index was observed at baseline and on Day 3 in complete pathologic responders (no statistical analysis performed).

CONCLUSIONS

Capecitabine 725 mg/m2 p.o., twice daily in combination with oxaliplatin 50 mg/m2/week and RT 50.4 Gy in 28 fractions is the recommended dose for future studies.

Évaluation de la radiosensibilité tumorale par l'imagerie fonctionnelle et métabolique : de la recherche à l'application clinique. Revue de la littérature

During the last half of century considerable research on radiosensitivity biomarkers has been published. However, to date there is no non-invasive marker of cellular radiosensitivity identified for clinical routinely use. In this review, the main functional and metabolic imaging isotopic techniques for tumor radiosensitivity that have been explored over the last years are being described. This indirect evaluation fall into 3 topics associated with tumor proliferation rate or apoptosis, tumor hypoxic fraction, neoangiogenesis and the intrinsic radiosensitivity of clonogenic tumor cells. The final objective of the radiosensitivity monitoring during radiotherapy would be to adapt treatment strategy for overcoming the identified radioresistance mechanism such as hypoxia by the addition of radiosensitisers for example. This would allow better tumor control rather than continue inefficient and costly treatment delivery, which in addition could compromise outcome.

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.

Pathological and molecular predictors of the response of rectal cancer to neoadjuvant radiochemotherapy

AIMS

The prediction of sensitivity and resistance to neoadjuvant therapy has great potential value for many tumour sites. A neoadjuvant regimen is increasingly the gold standard in rectal cancer management and the aim of this review was to highlight predictive markers currently assessed and evaluate their clinical utility.

METHODS

A systematic search of Medline was conducted using the following keywords 'colorectal', 'neoadjuvant', 'molecular', 'predict' and 'radiotherapy'. Original manuscripts from all relevant listings were sourced. These were hand searched for further articles of relevance.

RESULTS

Conventional indices including tumour stage and grade were unable to predict histological response. Immunohistochemical assessment of P53 gene, Bcl 2, Bax and microsatellite instability are of no predictive value. Studies utilising molecular response predictors from archival pre-treatment tumour tissues have identified several promising predictive markers including p21, spontaneous apoptosis and direct sequencing of the p53 gene. Global gene expression from fresh pre-treatment tissue using cDNA microarray has only recently been assessed but identified expression differences between 54 genes and was able to predict response with 78% sensitivity and 86% specificity.

CONCLUSIONS

Currently there are no clinically useful predictors of response based on standard pathological assessment and immunocytochemistry. Direct gene sequencing of p53, studies of apoptosis and global gene sequencing may hold promise.

Survivin as a radioresistance factor, and prognostic and therapeutic target for radiotherapy in rectal cancer

Apoptosis levels have been shown to predict tumor response to preoperative radiochemotherapy in rectal cancer. Recently, the prominent role of survivin, a structurally unique member of the inhibitor of apoptosis protein family, has been shown in colorectal cancer tumorigenesis and prognosis. In this study, we investigated whether survivin plays a direct role in mediating radiation resistance. We used short interfering RNA molecules to decrease survivin in radioresistant SW480 and intermediately radioresistant HCT-15 colorectal cancer cells. This resulted in a significant decrease of survivin mRNA and protein expression with a maximum at 24 to 48 hours after transfection. If irradiated during this sensitive period, an increased percentage of apoptotic cells and an increased caspase 3/7 activity in parallel with a decreased cell viability and a reduced clonogenic survival was shown. These effects were more pronounced in the radioresistant SW480 cell line with a radiation-induced cytotoxicity enhancement factor at 10% and 50% survival of 1.8 to 2.2 for SW480 and 1.5 to 1.7 for HCT-15, respectively. Furthermore, transfection with survivin short interfering RNA increased levels of G2-M arrest and levels of DNA double-strand breaks in irradiated cells. These observations indicate that cell cycle and DNA repair mechanisms may be associated with apoptosis induction in tumor cells that are otherwise resistant to killing by radiation. In a translational study of 59 patients with rectal cancer treated with a combination of radiotherapy and chemotherapy, increased survivin expression was inversely related to the levels of apoptosis, and was also associated with a significantly higher risk of a local tumor recurrence.

Effectiveness of gene expression profiling for response prediction of rectal adenocarcinomas to preoperative chemoradiotherapy

PURPOSE

There is a wide spectrum of tumor responsiveness of rectal adenocarcinomas to preoperative chemoradiotherapy ranging from complete response to complete resistance. This study aimed to investigate whether parallel gene expression profiling of the primary tumor can contribute to stratification of patients into groups of responders or nonresponders.

PATIENTS AND METHODS

Pretherapeutic biopsies from 30 locally advanced rectal carcinomas were analyzed for gene expression signatures using microarrays. All patients were participants of a phase III clinical trial (CAO/ARO/AIO-94, German Rectal Cancer Trial) and were randomized to receive a preoperative combined-modality therapy including fluorouracil and radiation. Class comparison was used to identify a set of genes that were differentially expressed between responders and nonresponders as measured by T level downsizing and histopathologic tumor regression grading.

RESULTS

In an initial set of 23 patients, responders and nonresponders showed significantly different expression levels for 54 genes (P < .001). The ability to predict response to therapy using gene expression profiles was rigorously evaluated using leave-one-out cross-validation. Tumor behavior was correctly predicted in 83% of patients (P = .02). Sensitivity (correct prediction of response) was 78%, and specificity (correct prediction of nonresponse) was 86%, with a positive and negative predictive value of 78% and 86%, respectively.

CONCLUSION

Our results suggest that pretherapeutic gene expression profiling may assist in response prediction of rectal adenocarcinomas to preoperative chemoradiotherapy. The implementation of gene expression profiles for treatment stratification and clinical management of cancer patients requires validation in large, independent studies, which are now warranted.

P27 does not predict histopathological response to radiochemotherapy in rectal cancer

BACKGROUND

Tumor response to radiochemotherapy (RCT) varies considerably, even among patients treated in accordance with the same protocol. The aim of the present study was to test the predictive value of the cell-cycle inhibitor p27kip1 with regard to neoadjuvant RCT response in rectal cancer.

MATERIALS AND METHODS

P27kip1 was evaluated by immunohistochemistry in pretreatment biopsy material obtained from 42 patients with rectal cancer treated uniformly in accordance with an identical prospective neoadjuvant RCT protocol (CAO/AIO/ARO-94). Four expression patterns (staining intensity [-,+,++,+++] and the percentage of positive cells, evaluated separately for nuclei and cytoplasm) of p27kip1 were investigated for correlation with tumor response, which was assessed in the resected surgical specimen using a histopathological five-point grading system. Additionally, p27(kip1) expression was investigated for correlation with several pathological features, overall survival, and disease-free survival.

RESULTS

p27kip1 expression was as follows: nuclear intensity: -: 8, +: 19, ++: 11, +++: 4 cases, median percentage of positive cells: 18.75%; cytoplasmic intensity: -: 0, +: 25, ++: 12, +++: 3 cases, median percentage of positive cells: 70%. Histopathological tumor regression was acceptable in 30 patients (3 complete; 27 good) and inadequate in 12 patients (7 moderate; 5 minimal). No tumor failed to show some regression. No significant correlation was found between any of the p27kip1 expression patterns and RCT response, tumor differentiation (low grade versus high grade), cT- and ypT-category, UICC stage, overall survival, and disease-free survival.

CONCLUSIONS

p27kip1 cannot aid the individualization of multimodal treatment strategies in rectal cancer, nor can it serve as a predictor of survival.

Spontaneous and radiation-induced apoptosis in colorectal carcinoma cells with different intrinsic radiosensitivities: survivin as a radioresistance factor

BACKGROUND

Spontaneous apoptosis has been shown to predict tumor response to radiochemotherapy in rectal cancer in vivo. It remains to be elucidated, however, which genetic profile determines whether a tumor is more or less prone to apoptosis. Recently, a novel member of the inhibitor of apoptosis protein family, designated survivin, was identified. We investigated the impact of survivin expression on tumor cell apoptosis in three colorectal cell lines of different intrinsic radiosensitivities.

METHODS AND MATERIALS

Survivin protein expression was measured by Western blot analysis, and survivin mRNA expression by quantitative TaqMan reverse transcription polymerase chain reaction, both in untreated cell and after irradiation with 2 and 8 Gy. The expression profile was then correlated to spontaneous and radiation-induced apoptosis (Tunel-Assay, DAPI-staining) in three colorectal cell lines of low (SW 480), intermediate (HCT-15), and high radiosensitivity (SW 48), as determined by the colony-forming assay.

RESULTS

In vitro analysis revealed higher spontaneous and higher radiation-induced apoptosis rates in the radiosensitive line (SW 48), as compared with the more resistant line (SW 480). In Western blot analysis and in TaqMan analysis, SW 480 was characterized by a higher spontaneous expression and a pronounced induction of survivin 48 h after irradiation, whereas survivin expression was low when untreated and not increased after irradiation in the most radiosensitive line SW 48. HCT-15 was intermediate, both with respect to the level of survivin mRNA and protein expression.

CONCLUSION

The inverse correlation of survivin-expression with spontaneous and radiation-induced apoptosis suggests that survivin is an important inhibitor of apoptosis in colorectal cancer cell lines. Analysis of survivin mRNA or protein expression may therefore provide predictive information on radio- and chemoresistance of individual colorectal tumors.

Nuclear medicine imaging to predict response to radiotherapy: a review

PURPOSE

To review available literature on positron emission tomography (PET) and single photon emission computerized tomography (SPECT) for the measurement of tumor metabolism, hypoxia, growth factor receptor expression, and apoptosis as predictors of response to radiotherapy.

METHODS AND MATERIALS

Medical literature databases (Pubmed, Medline) were screened for available literature and critically analyzed as to their scientific relevance.

RESULTS

Studies on 18F-fluorodeoxyglucose PET as a predictor of response to radiotherapy in head-and-neck carcinoma are promising but need confirmation in larger series. 18F-fluorothymine is stable in human plasma, and preliminary clinical data obtained with this marker of tumor cell proliferation are promising. For imaging tumor hypoxia, novel, more widely available radiopharmaceuticals with faster pharmacokinetics are mandatory. Imaging of ongoing apoptosis and growth factor expression is at a very early stage, but results obtained in other domains with radiolabeled peptides appear promising. Finally, for most of the tracers discussed, validation against a gold standard is needed.

CONCLUSION

Optimization of the pharmacokinetics of relevant radiopharmaceuticals as well as validation against gold-standard tests in large patient series are mandatory if PET and SPECT are to be implemented in routine clinical practice for the purpose of predicting response to radiotherapy.

Endorectal ultrasound and magnetic resonance imaging in rectal cancer staging

The majority of rectal cancers have local disease only at presentation, but despite meticulous surgery, a number of factors will influence outcome. Preoperative identification of adverse prognostic factors provides a rational basis for selecting preoperative therapy. Thin section MRI can influence preoperative therapeutic algorithms by T and N staging, demonstrating operability, and the potential risk of circumferential margin involvement. Endosonography may contribute to this, but has a greater role in determining intramural invasion for early tumors. The assessment of residual tumor after chemoradiotherapy remains difficult; PET scanning has been used in this situation [32], but has not been compared with MRI and is unlikely to show only residual cells with extensive fibrosis.

Enhanced tumor killing by Apo2L/TRAIL and CPT-11 co-treatment is associated with p21 cleavage and differential regulation of Apo2L/TRAIL ligand and its receptors

Apo2L/TRAIL exhibits enhanced apoptotic activity in tumor xenograft models when used in combination with the topoisomerase 1 inhibitor CPT-11. To investigate the cellular mechanisms involved in this increased tumor-killing activity, a series of in vitro experiments were conducted using the human colon carcinoma cell line (HCT116). Apo2L/TRAIL induced a transient upregulation of DR5 mRNA, while CPT-11 increased both death and decoy receptor expression. Upregulation of decoy receptors by CPT-11 was partially inhibited by co-administration of Apo2L/TRAIL. CPT-11 treatment resulted in accumulation of cells at G(2)M-phase and correlated with a substantial increase in the protein levels of the cyclin-dependent kinase inhibitor p21. However, cells co-treated with CPT-11 and Apo2L/TRAIL, or pretreated with CPT-11 for up to 24 h followed by 2 h Apo2L/TRAIL, resulted in a caspase-dependent degradation of p21, reversal of G(2)-M phase arrest with a concomitant increase in apoptosis. The sequential treatment produced the greatest induction of DR5 and DR4, caspase-3-like cleavage/activation and p21 degradation, as well as increased apoptosis. These data indicate that the up-regulation of Apo2L/TRAIL ligand and its death receptors as well as cleavage of p21 protein in the Apo2L/TRAIL plus CPT-11 treatment contributes to the positive cooperation between these agents in enhancing tumor cell apoptosis.

Extracellular matrix proteins and chemoradiotherapy: alpha5beta1 integrin as a predictive marker in rectal cancer

AIMS

To investigate the effects of extracellular matrix (ECM) protein expression on the rates of apoptosis and proliferation in rectal cancers and subsequent response to chemoradiotherapy (CRT).

METHODS

The expression of fibronectin, collagen IV, laminin and the fibronectin receptor (FnR, alpha5beta1 integrin) were analysed in 32 pre-treatment rectal cancer biopsies by immunohistochemistry. ECM expression was correlated with tumour mitotic index (MI), apoptotic index (AI) and histopathological response to CRT.

RESULTS

18/32 cancers showed a poor response and 14/32 a good response (5/14 with complete pathological response) to CRT. Moderate to strong staining was seen in 22/32 cancers for fibronectin, 5/32 for collagen IV and 18/32 for laminin. Tumour FnR was related to stromal fibronectin content, and was significantly associated with CRT response; good responders having higher FnR expression compared to poor responders. No association was found between FnR expression and either MI or AI in pre-treatment biopsies, nor between MI or AI and CRT response.

CONCLUSIONS

Tumour FnR expression is independent of MI and AI, and may serve as a useful marker for CRT response in rectal cancer.

Apoptosis as a cellular predictor for histopathologic response to neoadjuvant radiochemotherapy in patients with rectal cancer

BACKGROUND

Tumor shrinkage by preoperative radiochemotherapy (RCT) can markedly improve surgery in locally advanced (T4) rectal cancer with clear resection margins and may enable sphincter preservation in low-lying tumors. However, tumor response varies considerably, even among tumors treated according to the same protocol. If one is able to identify patients with highly radio-responsive tumors at the time of diagnosis, a selective and individualized policy of preoperative RCT might be pursued.

METHODS

The apoptotic index (AI), Ki-67, p53, and bcl-2 were evaluated by immunohistochemistry on pretreatment biopsies from 44 patients treated uniformly according to a prospective neoadjuvant RCT protocol (CAO/AIO/ARO-94). Treatment response was assessed histopathologically in the resected surgical specimen, using a five-point grading system. Expression of each marker was correlated with tumor response and relapse-free survival after curative surgery.

RESULTS

Tumors with complete (n = 3) or good (n = 28) response to RCT showed significantly higher pretreatment levels of apoptosis (mean AI: 2.06%) than tumors with moderate (n = 7), minimal (n = 5), or no regression (n = 1) from RCT (AI: 1.44%, p = 0.003). The AI was significantly related to Ki-67 (p = 0.05), but not to p53 and bcl-2 status. Tumor regression and AI best predicted relapse-free survival after combined modality treatment and curative surgery.

CONCLUSION

Spontaneous apoptosis in rectal cancer may serve as an important predictor of tumor regression from RCT in rectal cancer and as a significant prognosticator of relapse-free survival. Thus, this molecular marker may finally help to tailor therapy with regard to (neo-) adjuvant treatment of rectal cancer.

Spontaneous and inducible apoptosis in oesophageal adenocarcinoma

The use of neoadjuvant chemoradiotherapy prior to surgery in the treatment of oesophageal adenocarcinoma has increased in recent years, and up to 25% of patients will have a complete pathological response to the neoadjuvant therapy. Many patients will not respond, however, and the knowledge of molecular factors predicting response or resistance to chemoradiotherapy is required to enhance treatment results. An understanding of apoptosis and cell proliferation may be relevant and this study focused on apoptotic indices and cell-cycle related (Ki-67, p53 and bcl-2) protein expression in a cohort of 42 patients with primary oesophageal adenocarcinoma. We documented that apoptosis occurs among viable (proliferating) tumour cells in all adenocarcinoma cases examined in this study. Pre-operative chemoradiotherapy significantly increased apoptosis and significantly decreased cell proliferation (estimated by Ki-67 expression). Immunohistochemically detected p53 and bcl-2 gene products had no regulatory role in the apoptotic process. The cumulative expression of p53 protein is significantly associated with increasing proliferation activity. Evaluation of apoptosis in pre-treatment specimens may have potential utility in predicting the efficacy of treatment. Assessment of the tumours proliferation activity by Ki-67 expression might identify patients who are at risk of developing metastatic disease.

Immunohistochemical detection of the anti-apoptosis protein, survivin, predicts survival after curative resection of stage II colorectal carcinomas

BACKGROUND

This study examined the role of Survivin protein, a novel inhibitor of apoptosis, in determining prognosis after curative resection of stage II colorectal carcinomas.

METHODS

Expression of Survivin, P53, and BCL-2 was evaluated immunohistochemically in stage II colorectal carcinomas from 49 patients who were followed for up to 9 years after operation. The Cox proportional hazards regression model was used to examine the predictive value of several covariates.

RESULTS

The patients comprised 33 men and 16 women with a median age of 71 years. There were 32 colonic and 17 rectal cancers comprising 40 T3 and nine T4 primary tumors. Survivin was expressed in 30 (61.2%), P53 in 30 (61.2%), and BCL-2 in 21 (42.9%) tumors. Expression of Survivin was independent of P53 or BCL-2 expression and histopathological characteristics of the tumor. The 5-year survival rate of patients with Survivin-positive tumors was significantly lower than that of patients with Survivin-negative tumors (52.5% vs. 94.1%, respectively; P = .01). On multivariate analysis, expression of Survivin (Hazard Ratio [HR] = 9; P = .03), and rectal origin of cancer (HR = 3; P = .05) were the only factors which independently predicted an increased risk of death from recurrent cancer.

CONCLUSION

Survivin expression within the tumor can identify patients with stage II colorectal carcinoma who are at increased risk of death from recurrent disease and might particularly benefit from adjuvant therapy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Predictive and prognostic markers in gastrointestinal cancers

As the roles of specific genes and their functions in cancer etiology and progression become defined, the necessity of looking at multiple genes and their interaction becomes clearer. In gastrointestinal cancer, tumor suppressor and promoter genes, cell cycle control and angiogenic factors, repair genes, and metabolic genes have been examined as they relate to prognosis and therapeutic outcomes. To date, most correlative studies for specific molecular parameters have been done retrospectively. Methodologies, sample sizes, and definitions differ. The following analysis provides a brief review of the current state of knowledge and recent research on the most commonly studied molecular markers, and the newer areas of inquiry attempting to define how to use molecular-genetic features of individual tumors as targets for more effective therapies. Consideration is given to the design of trials employing molecular targets as outcome factors.

Apoptosis in rectal carcinoma: prognosis and recurrence after preoperative radiotherapy

BACKGROUND

Rectal carcinoma is common, with considerable local recurrence and death rates. Preoperative radiotherapy and refined surgical techniques can improve local control. The aim of this study was to investigate the interaction between apoptosis and the outcome of rectal carcinoma, with and without short-term preoperative radiotherapy.

METHODS

Specimens were from 162 patients from the Southeast Swedish Health Care region included in the Swedish Rectal Cancer Trial between 1987-1990. New sections from the paraffin blocks of the preoperative biopsies and the surgical specimens were examined for apoptosis using the terminal deoxynucleotidyl transferase mediated digoxigenin nick end labeling (TUNEL) method.

RESULTS

The mean percentage of apoptotic cells was 0.3% (0-4%) and 1.1% (0-14.5%) for the preoperative biopsy and the surgical specimen, respectively. The authors analyzed the surgical specimens from nonirradiated patients and divided them into three groups by apoptotic index (AI) as follows: 0%, 0-1%, and > 1%. A high AI was associated with a decreased local recurrence rate compared with an intermediate or a low AI (P = 0.024). There was no significant relation between AI and survival. There was a significant reduction in the local recurrence rate for irradiated patients compared with the nonirradiated in the low (P = 0.015) and intermediate (P = 0.038) AI groups. In the high AI group, there were few recurrences and no significant difference was observed between irradiated and nonirradiated patients. The relative risk of death from rectal carcinoma in Dukes A-C patients was not significantly decreased by radiotherapy, but, in the intermediate AI group, there was a trend (P = 0.08) in favor of the irradiated patients.

CONCLUSION

A high AI in rectal carcinoma indicated a decreased local recurrence rate.

Molecular prognostic factors in rectal cancer treated by radiation and surgery

PURPOSE

The aim of this study was to determine the biologic significance of tumor response and the prognostic value of molecular markers in a group of patients with rectal cancer treated with preoperative radiation therapy and radical surgery.

METHODS

Microsatellite instability, microvessel count, and immunohistochemistry for proliferating cell nuclear antigen, p53, p21, bcl-2, and vascular endothelial growth factor were performed in the preradiation biopsy specimen of 72 patients with rectal cancer treated by preoperative radiation therapy and radical curative surgery. Preoperative tumor stage by endorectal ultrasound was compared with pathology stage of the resected specimen. Mean follow-up was 50 months.

RESULTS

Twenty-eight patients (39 percent) responded to radiation therapy. The response was complete in 8 (12 percent) and partial in 20 patients (27 percent). Tumors with positive nodes in the surgical specimen were less likely to have responded to preoperative radiation (P = 0.03). Only p21 expression was individually associated with response to radiation (56 vs. 30 percent; P = 0.03). Tumors that were p53-negative/p21-positive or p21-positive/bcl-2-positive were also more likely to respond to radiation (83 vs. 35 percent; P = 0.03 and 71 vs. 31 percent; P = 0.01, respectively). The tumor relapsed in 21 patients (29 percent): locally in 7 (10 percent) and distally in 14 (19 percent). Recurrence was associated with lack of response to radiation, female gender, distal tumor location, high proliferating cell nuclear antigen labeling index, and low microvessel count. Probability of survival was greater for patients with well or moderately differentiated tumors and tumors that responded completely to radiation.

CONCLUSIONS

Tumor response to radiation is associated with improved tumor control and overall survival rate, and p21 expression is a marker of tumor radiosensitivity in patients with rectal cancer. Furthermore, a high proliferating cell nuclear antigen labeling index and a low microvessel count in the preradiation biopsy specimen may be prognostic indicators for tumor recurrence.

Apoptosis, p53, bcl-2, and Ki-67 in invasive bladder carcinoma: possible predictors for response to radiochemotherapy and successful bladder preservation

PURPOSE

Several groups have reported the value of bladder preservation by a combined treatment protocol, including transurethral resection (TUR-B) and radiochemotherapy (RCT). As more experience is acquired with organ-sparing treatment, patient selection should be optimized. The purpose of this study was to investigate the role of several biologic markers that may predict response to RCT in muscle-invasive bladder carcinoma.

METHODS AND MATERIALS

The apoptotic index (AI), Ki-67, p53, and bcl-2 were evaluated by immunohistochemistry on pretreatment biopsies from 70 patients treated for invasive bladder cancer by TUR-B and RCT. Expression of each marker was correlated with initial response, local control, and cancer-specific survival with preserved bladder. An exploratory multivariate analysis was also performed that included clinical and immunohistochemical variables.

RESULTS

A high AI (> median = 1.6%) and a high Ki-67 index (> median = 8.8%), but not the p53- and bcl-2 expression, were significantly related to initial complete response (CR) and local control with preserved bladder after 5 years. When the AI and Ki-67 expression were considered simultaneously, the association with initial CR (p < 0. 001), local control (p = 0.0002), and cancer-specific survival with preserved bladder (p = 0.008) was highly significant. In an exploratory multivariate analysis (final model), only AI, Ki-67, and the combined AI/Ki-67 variable retained significance for local control with preserved bladder at 5 years.

CONCLUSION

Patients with a high spontaneous AI and a high pretreatment Ki-67 index should be considered preferentially for treatment with RCT, whereas tumors with low proliferation and low levels of apoptosis are less likely to respond to RCT.

p53 Protein accumulation as a prognostic marker of preoperative radiotherapy and/or chemotherapy in advanced squamous cell esophageal carcinoma--preliminary report

The correlation between immunohistochemical detection (IH) of p53 protein and tumor response to preoperative chemotherapy and/or radiotherapy in advanced esophageal squamous cell carcinoma was evaluated. Fifty-six patients with advanced esophageal squamous cell carcinoma were included in the study. All patients were staged and diagnosed microscopically before treatment. Patients were divided into three groups: 17 patients treated with chemotherapy and radiotherapy preoperatively (group I) (cisplatin and 5-fluorouracil, cobalt-60 therapy; total dose 3000 Gy); 19 patients treated with chemotherapy only (group II); and 20 patients who did not receive preoperative therapy (group III). The response of the tumor tissue to preoperative treatment was evaluated macroscopically and microscopically in operated specimens according to the classification: CR, complete response; PR1, major partial response with regression of at least 50% of initial tumor mass; PR2, minor partial response with regression of less than 50% of initial tumor mass. In all 56 patients immunohistochemistry was used to detect anti-p53 antibody (Dako, DO-7) in normal mucosa and cancer tissue. The response of the tumor was similar in both group I and group II. p53 protein was not expressed in the normal esophageal mucosa. A high level of p53 in operated specimens was associated with unfavorable tumor response to preoperative treatment. Therefore, immunohistochemical detection of p53 protein can be considered to predict the outcome of preoperative therapy.