Correlation Between Biomarker Candidate Proteins with the Effect of Neoadjuvant Chemoradiation Therapy on Esophageal Squamous Cell Carcinoma

Background

While chemoradiation therapy (CRT) is one of the most useful treatments for esophageal squamous cell carcinoma (ESCC), it is important to predict response prior to treatment by using markers because some patients respond well and others do not.

Methods

Fifty-nine patients with ESCC were treated with neoadjuvant CRT at the Kagoshima University Hospital. The expression of seven types of biomarker candidate proteins in biopsy specimens of untreated primary tumors was evaluated to determine whether it correlated with response and prognosis.

Results

The positive expression rates were 47% for p53, 83% for CDC25B, 68% for 14-3-3sigma, 76% for p53R2, 75% for ERCC1, 32% for Gli-1, and 54% for Nrf2. In terms of histological response, tumor grade of the 59 patients was 48.8% for grade 1 as the non-responder, 29.2% for grade 2, and 22.0% for grade 3 as the responder. CRT was significantly effective in p53(?), p53R2(?), ERCC1(?), and Nrf2(?) tumors, while p53(?), p53R2(?), and ERCC1(?) were factors independently correlated with effective histological response. Their combined expression of two or three negative expressions had 100% effective response and was a significant prognostic factor.

Conclusion

Our results suggest that two or three negative expressions of p53, p53R2, and ERCC1 in biopsy specimens of primary tumors were associated with a favorable response to CRT for ESCC. Assessment of tumor suppressor and DNA repair protein expressions in biopsy specimens may be useful for the potential utility of CRT therapy for patients with ESCC prior to treatment.

     

Prediction of the response to chemoradiation and prognosis in oesophageal squamous cancer

BACKGROUND: The sensitivity of cancer cells to chemotherapy and radiation therapy depends on various biological properties. This study investigated the expression of p53, CDC25B and metallothionein (MT), and evaluated their clinical significance in chemoradiation therapy (CRT) for oesophageal squamous cell carcinoma.METHODS: The expression of p53, CDC25B and MT was evaluated by immunohistochemistry using biopsy specimens taken before CRT for 77 patients with oesophageal squamous cell carcinoma, and correlated with the pathological effects of CRT and survival.RESULTS: p53-positive tumours and MT-positive tumours had a poor response to CRT, whereas tumours with strong CDC25B expression were associated with a good response. When each patient was scored for the presence of the three biological factors, there was a strong correlation between the sensitivity score and the pathological effect of CRT (P < 0.001), and a (non-significant) difference in the 5-year survival rate between patients with a high score and those with a low score (67 versus 34 per cent respectively; P = 0.12).CONCLUSION: The combined evaluation of p53, CDC25B and MT may help to identify patients with advanced oesophageal squamous cell carcinoma who will benefit from preoperative CRT.     

Endoscopic ultrasonography is useful for monitoring the tumor response of neoadjuvant chemoradiation therapy in esophageal squamous cell carcinoma

BackgroundRecently, neoadjuvant chemoradiation therapy (CRT) has been introduced for treatment of esophageal squamous cell carcinoma (ESCC). This study was performed to investigate the usefulness of endoscopic ultrasonography (EUS) in comparison with EUS findings before and after CRT, and histologic findings.MethodsThere were 33 patients with potentially resectable ESCC who underwent neoadjuvant CRT. Preoperative EUS and histologic findings were compared. EUS criteria were established on the basis of low and high echoic regions. Resected specimens were examined by hematoxylin-eosin, azan, and cytokeratin immunohistochemical staining.ResultsAzan and cytokeratin staining clearly delineated fibrous changes and residual tumor. Low echoic regions corresponded to residual tumor and high echoic spots corresponded to fibrosis. All 12 patients classified as grade 1 on EUS diagnosis had histologic grade 1 tumors. Nineteen of 21 cases that presented with high echo were grade 2 or 3. The prognosis according to EUS diagnosis was similar to the histologic effect.ConclusionsPreoperative EUS findings reflected the histologic effect after neoadjuvant CRT. EUS is a useful tool to assess the effect for CRT and to predict the prognosis in ESCC patients.     

Cell-Cycle Regulators and the Ki-67 Labeling Index Can Predict the Response to Chemoradiotherapy and the Survival of Patients With Locally Advanced Squamous Cell Carcinoma of the Esophagus

Background: We investigated whether aberrant p53 and p16 expression, the Ki-67 labeling index (LI), and int-2/cyclin D1 gene amplification predict the response to chemoradiotherapy (CRT) in patients with locally advanced esophageal squamous cell carcinoma (ESCC).Methods: p53 and p16 expression status, the Ki-67 LI, and int-2/cyclin D1 amplification were assessed by immunohistochemical staining and slot blot analysis in pretreatment endoscopic biopsy specimens of 41 patients with T4 or M1 Lym (distant lymph node metastasis) ESCC. All patients received a course of chemotherapy (5-fluorouracil and cisplatin) with radiotherapy.Results: The CRT therapeutic response rate was 71%, and resection after CRT was successful in 15 of the cases in which the CRT effect was significant. The cumulative survival rate after CRT in the p53-negative patients was significantly higher than in the p53-positive patients (P = .037). The mean Ki-67 LI in the CRT response cases was significantly higher than in the CRT no-response cases (P = .023). Multivariate regression analysis revealed high Ki-67 LI to be an independent variable linked to a pathologic complete response to CRT (P = .033). The cumulative survival rate after CRT in the group that was p53-negative and int-2/cyclin D1 amplification-positive was significantly higher than in the other groups (P = .008).Conclusions: Evaluating predictive factors in pretreatment endoscopic biopsy specimens may allow selection of more suitable multimodal treatment for ESCC patients and improve their quality of life.     

Combined analysis of p53 and retinoblastoma protein expressions in esophageal cancer

BACKGROUND: p53 gene mutation and abnormal p53 protein expression, also loss of the retinoblastoma gene and protein expression are frequently associated with esophageal squamous cell carcinoma (ESCC). Recently, the prognostic significance of the combined analysis of p53 protein and retinoblastoma protein (pRB) has been reported in non-small cell lung cancer. However, in ESCC, the prognostic significance of the combined analysis of these proteins remains unclear. In this study, we immunohistochemically analyzed the p53 protein and pRB expressions in surgically resected ESCC, and we evaluated the prognostic significance of the combination of these proteins. METHODS: We analyzed p53 protein and pRB expressions immunohistochemically in 191 surgically resected ESCC cases. Overexpression of p53 and loss of pRB were considered abnormal. RESULTS: Overexpression of p53 protein was detected in 79 patients (41%) and decreased pRB nuclear staining occurred in 82 (43%). The Kaplan-Meier survival curve showed that absence of pRB expression was significantly associated with shortened survival (p = 0.001), whereas expression of p53 was not significantly associated with survival. Moreover, p53 and pRB status individually were not independent prognostic factors in multivariate survival analysis. With respect to pRB and p53, the tumors could be grouped into four categories: p53-/pRB+ (31%); p53-/pRB- (27%); p53+/pRB+ (26%); and p53+/pRB- (16%). Favorable prognosis was observed in patients with p53-/pRB+ tumors. Multivariate analysis showed p53-/pRB+ status to be an independent prognostic factor. CONCLUSIONS: The combination of p53 protein loss and pRB expression was associated with good prognosis in patients with ESCC.     

The Usefulness of Neoadjuvant Chemoradiation Therapy for Locally Advanced Esophageal Cancer with Multiple Lymph-Node Metastases

Background

The prognosis of patients with esophageal squamous-cell cancer (ESCC) and multiple lymph-node metastases is quite poor. We examined whether neoadjuvant chemoradiation therapy (CRT) has a beneficial effect in such patients.

Methods

A total of 50 consecutive patients with T3–4 tumors and without organ metastases were prospectively enrolled. Of those patients, 20, who had four or more nodal metastases, underwent neoadjuvant CRT (CRT group), and the remaining 30 patients, who had three or fewer nodal metastases, underwent surgery alone (surgery group). CRT consisted of 5-fluorouracil plus cisplatin and 40 Gy of radiation. The groups’ clinical outcomes were compared.

Results

Surgery was performed in 48 patients: all enrolled patients except for 2 who had organ metastasis after CRT. In the CRT group, the number of patients with pathological complete response was observed in 8 patients (44 %), mean nodal metastases number was changed from 8.2 to 2.6 and 9 patients had pN0. The 3-year survival rate was 76 % in the CRT group (4 patients relapsed) and 68 % in the surgery group (8 patients relapsed), which is not a statistically significant difference (P = 0.61).

Conclusions

Neoadjuvant CRT is beneficial for locally advanced ESCC with four or more lymph-node metastases.     

Prognosis of Esophageal Squamous Cell Carcinoma in Patients Positive for Human Epidermal Growth Factor Receptor Family Can Be Improved by Initial Chemotherapy with Docetaxel,Fluorouracil, and Cisplatin

Background  

The human epidermal growth factor receptor (HER) family, Ki-67 and p53 are important biomarkers for several malignancies. However, few studies have examined the role of these in prognosis and therapeutic sensitivity of esophageal squamous cell carcinoma (ESCC). The efficacy of triple-drug combination therapy with docetaxel, fluorouracil and cisplatin has recently been expected for ESCC.     

p53 Mutation Status Predicts Pathological Response to Chemoradiotherapy in Locally Advanced Esophageal Cancer

Background and Objectives

The p53 gene promotes cell-cycle arrest and apoptosis upon DNA damage and is associated with chemo- and radiosensitivity of cancer cells. However, its clinical significance has not been confirmed, especially in squamous cell carcinoma of the esophagus (ESCC). We investigated the correlation between p53 disorders (gene mutation and protein accumulation) and the effects of chemoradiotherapy (CRT).

Patients and Methods

Biopsy specimens obtained before CRT (40–60 Gy; low-dose 5-fluorouracil plus cisplatin) from 64 patients with locally advanced (T2–T4) ESCC were examined for p53 gene mutations (MT) of exons 4–9 by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and protein accumulation by immunohistochemistry (IHC). These were correlated with the pathological effects of CRT and cause-specific survival.

Results

Pathological complete response (pCR) was observed in 21.9% (14/64) patients, who showed better survival than non-pCR patients (2-year survival 78.6% versus 40.5%, P = 0.007). p53 mutation (MT)+ and p53 IHC+ were observed in 31.3% (20/64) and 65.6% (42/64) patients, respectively, and each was significantly associated with non-pCR (P = 0.004 and 0.042, respectively). Combined evaluation of p53 MT and p53 IHC correlated well with pCR frequency, showing 0% (0/12) for MT+/IHC+, 0% (0/8) for MT+/IHC–, 20% (6/30) for MT–/IHC+ and 57.1% (8/14) for MT–/IHC–. These results indicate that presence of p53 mutations was associated with non-pCR regardless of IHC status, and that p53 immunoreactivity was helpful in predicting non-pCR among p53 mutation-negative patients.

Conclusion

Analysis of ESCC biopsy specimens for p53 gene mutation can identify patients who will not achieve pCR by CRT. The results should be confirmed by large cohort prospective studies.     

Factors Influencing the Long-Term Survival in Patients with Esophageal Cancer Who Underwent Esophagectomy After Chemoradiotherapy

Background

Salvage esophagectomy is potentially the only treatment available that can offer a chance of long-term survival when definitive chemoradiotherapy (CRT) fails to achieve local control for patients with esophageal squamous cell carcinoma (ESCC). However, salvage esophagectomy is a highly invasive procedure with various postoperative complications compared to planned esophagectomy after neoadjuvant chemoradiotherapy (CRT). We hypothesize that severe postoperative complications may affect not only surgical mortality but also tumor recurrence and long-term survival for patients with salvage esophagectomy after definitive CRT.

Methods

For the present study we reviewed the surgical procedures, postoperative complications, and the prognosis of 65 consecutive patients with thoracic ESCC who underwent the esophagectomy after neoadjuvant (neoadjuvant group: n = 40) or definitive (salvage group: n = 25) CRT.

Results

Most patients underwent right-transthoracic extended esophagectomy and reconstruction using gastric conduit by way of subcutaneous route with left cervical anastomosis. The incidence of postoperative pneumonia was found to be higher in the salvage group than in the neoadjuvant group. In both groups, the survival of patients with R0 resection was significantly better than those with R1/R2 resection. Moreover, in the salvage group, the postoperative survival rate of patients with pneumonia or bacteremia/sepsis was significantly lower than that for patients who did not suffer the same complications. In the neoadjuvant group, R0 resection was selected to be the only independent prognostic factor in univariate and multivariate analysis. In contrast, in the salvage group, R0 resection and bacteremia/sepsis remained significant and were independent of the other factors in multivariate analysis.

Conclusions

This study reveals that postoperative morbidity affects not only the perioperative mortality but also the long-term survival of patients with ESCC who undergo salvage esophagectomy after definitive CRT.     

High Serum Levels of Vascular Endothelial Growth Factor-A and Transforming Growth Factor-β1 Before Neoadjuvant Chemoradiotherapy Predict Poor Outcomes in Patients with Esophageal Squamous Cell Carcinoma Receiving Combined Modality Therapy

Background and Purpose

This study was aimed at using proximity ligation assay (PLA) followed by enzyme-linked immunosorbent assay (ELISA) to identify serum biomarkers that predict treatment response and survival for patients with esophageal squamous cell carcinoma (ESCC) undergoing neoadjuvant concurrent chemoradiotherapy (CCRT) followed by esophagectomy.

Methods

Seventy-nine patients with ESCC receiving CCRT of taxane-based/5-fluorouracil-based chemotherapy and 40 Gy followed by surgery were enrolled. Serum samples were collected before and <1 month after CCRT. Fifteen biomarkers were analyzed using PLA. Biomarkers significantly correlating with pathological response/survival were verified by ELISA. Associations of the serum level of biomarkers and clinical factors with pathological response, disease-free survival (DFS), and overall survival (OS) were evaluated by analysis of variance and log-rank tests.

Results

Thirty patients had complete response (38 %), 37 had microscopic residual disease (47 %), and 12 had macroscopic residual disease (15 %). With a median follow-up of 52.8 months, the median DFS was 43 months. Among the 15 biomarkers screened by PLA, vascular endothelial growth factor (VEGF)-A and transforming growth factor (TGF)-β1 were significantly associated with pathological response and/or DFS. These biomarkers were further analyzed by ELISA to confirm initial biomarker findings by PLA. After ELISA of these two markers, only VEGF-A levels were significantly correlated with pathological response. On multivariate analysis, patients with combined high pre-CCRT VEGF-A and TGF-β1 levels (greater than or equal to the median), independent of pathological response, had significantly worse DFS (11 months vs. median not reached; p = 0.007) and OS (16 vs. 46 months; p = 0.07).

Conclusions

Pre-CCRT serum VEGF-A and TGF-β1 levels may be used to predict pathological response and survivals for ESCC patients receiving combined-modality therapy.     

Correlation of p53 Status with the Response to Chemotherapy-Based Treatment in Esophageal Cancer: A Meta-Analysis

Background

The value of p53 status for predicting response to chemotherapy-based treatment in patients with esophageal cancer has been controversial. We conducted a meta-analysis to elucidate the correlation of p53 status with the response to chemotherapy-based treatment.

Methods

Studies were searched in PubMed, Embase, and Web of Science (up to September 2012). The p53 status and response to therapy were defined and standardized. Subgroup analyses based on the treatment and histopathology were performed to explore the usefulness of p53 status for predicting response to therapy in esophageal cancer. Sensitivity analyses were conducted by removing specific studies to assess the effects of study quality.

Results

We included 28 studies with 1497 cases in our meta-analysis. Wild-type form of p53 status (low expression of p53 protein and/or wild-type p53 gene) was associated with high response to chemotherapy-based treatment in esophageal cancer (total major response [MR]: risk ratio [RR] = 1.09, 95 % CI = 1.03–1.16, P = .003; pathological MR: RR = 1.15, 95 % CI = 1.06–1.25, P = .001; total complete response [CR]: RR = 1.08, 95 % CI = 1.00–1.17, P = .040). The similar correlation between the wild-type form p53 and response to therapy were also detected in subgroup analyses (total MR, pathological MR, and total CR in chemoradiotherapy subgroup; total MR in chemotherapy subgroup; total MR and pathological CR in esophageal squamous cell carcinoma [ESCC]). Additionally, patients with wild-type form p53 status had high pathological complete response rate to neoadjuvant chemoradiotherapy in ESCC.

Conclusions

The current meta-analysis suggested that p53 status might be a predictive biomarker for response to chemotherapy-based treatment in esophageal cancer.     

Microvessel density and regulators of angiogenesis in malignant and nonmalignant prostate tissue

The aim of this study was to investigate the relationship between microvessel density (MVD), positive and negative angiogenic factors, and established prognostic factors in prostate cancer (PC), and, to clarify the effect of angiogenic factors to angiogenesis. The vascularization of neoplastic, non-neoplastic prostate tissue was determined by CD34 immunostaining. Angiogenetic mediators VEGF, bFGF, TSP-1, and p53 were studied by immunohistochemistry. Neovascularization and p53, VEGF, and TSP-1 expressions of tumorous tissue were higher than non-tumorous tissue.The bFGF expression in these tissues was not different.The p53 expression was not correlated with the expressions of VEGF, bFGF, and TSP-1 in PC. Our results demonstrate a significant increase in MVD, VEGF, TSP-1, and p53 expressions in prostate tumorigenesis. The pretreatment sPSA was the only parameter demonstrating significant correlation with tumor grade and may have a value in the prediction of aggressive tumor behavior in PC.     

Bile acid promotes the proliferation of squamous cell carcinoma of the esophagus, independent of its inducing COX-2 expression

BACKGROUND: We have reported G1 progression and cyclooxygenase-2 (COX-2) induction during carcinogenesis of the squamous epithelium of the esophagus. As bile acid induces COX-2 expression and promotes carcinogenesis in the digestive tract, we investigated the effect of bile acid on the proliferation of squamous cell carcinoma of the esophagus (ESCC). MATERIALS AND METHODS: MTT assay, Western blot analysis of COX-2 and cell cycle-related molecules in the G1 phase (Rb, CDC25A, cyclin D1), and CDK2 kinase assay were performed on chenodeoxycholic acid (CDCA) exposure to ESCC cell lines (TE2R, TE3, TE13, TE15). RESULTS: In the presence of gradient bile acid concentration (up to 100 microm), growth of ESCC cell lines was stimulated at a low concentration (maximally at 20-30 microm), but suppressed at a higher concentration. Only a low dose of bile acid induced the expression of cyclin D1 and CDC25A and showed high Rb phosphorylation and high CDK2 kinase activity. In contrast, bile acid progressively induced COX-2 expression in a dose-dependent manner, regardless of its biphasic effects on cell proliferation, and a COX-2 specific inhibitor (JTE-522) did not suppress growth stimulation by a low dose of bile acid. CONCLUSIONS: Bile acid at a low dose stimulates the proliferation of ESCC by inducing G1-regulating molecules. However, COX-2 expression, which is also induced by bile acid, does not affect cell proliferation. Further work is needed to elucidate its role in carcinogenesis.     

Thrombospondin-1, vascular endothelial growth factor expression and their relationship with p53 status in prostate cancer and benign prostatic hyperplasia

OBJECTIVE: To evaluate the expression of thrombospondin-1 (TSP-1, a potent inhibitor of angiogenesis) and vascular endothelial growth factor (VEGF, an important angiogenic factor in solid tumours) in prostate cancer, and their relationship with p53 status. PATIENTS AND METHODS: Using immunohistochemistry, the expression of VEGF, TSP-1 and p53 was assessed in 82 archival tissue specimens from 23 patients with benign prostatic hyperplasia (BPH), 22 with localized prostate cancer and 37 with metastatic prostate cancer. Seven of the last group had received androgen deprivation therapy. The relationship between the expression of VEGF, TSP-1 and p53 status was also evaluated with tumour grade and stage in patients with prostate cancer. RESULTS: The seven patients receiving hormonal treatment were excluded from the analysis because androgen deprivation significantly increased TSP-1 and decreased VEGF expression (both P < 0.01). Immunohistochemical analysis showed significantly higher VEGF and significantly lower TSP-1 expression (both P < 0.01) in prostate cancer than in BPH tissues. There was also significantly higher VEGF and significantly lower TSP-1 expression (both P < 0.05) in tissues from metastatic than localized prostate cancer. There was no significant correlation between VEGF or TSP-1 expression and Gleason score, but a significant inverse correlation between TSP-1 and VEGF expression. There was a significant association between VEGF expression and p53 status (P < 0.05), but TSP-1 expression was not associated with p53 status. CONCLUSIONS: Angiogenic factors, including VEGF and TSP-1, might be important in the development and progression of prostate cancer. These changes seem to be influenced by p53 status. Identifying the angiogenic factors involved in prostate cancer might lead to the development of diagnostic or therapeutic strategies based on anti-angiogenesis.     

Molecular biomarkers as predictors of response to neoadjuvant chemoradiation therapy in rectal cancer

The standard management of locally advanced rectal cancer includes neoadjuvant chemoradiation therapy (CRT) with 5-fluorouracil (5-FU) and concurrent pelvic irradiation (RT) to 45–50.4 Gy. This regimen results in downstaging in approximately 60% of patients and a pathological complete response (pCR) in 20%. Response to CRT is associated with improved rates of survival, local control, and sphincter preservation. However, some tumors are completely resistant to CRT; thus, non-responding patients experience only the toxicity of this treatment without any of its benefits. The ability to predict an individual patient’s response to CRT would enable delivery of more effective treatment: patients predicted to respond would be directed to undergo CRT, while those predicted not to respond would be guided to alternative therapies or primary surgical resection. Molecular biomarkers have significant potential for predicting tumor regression. Furthermore, they may represent novel targets for therapeutic agents. Many studies have yielded promising results; to date, however, they have often lacked reproducibility. This review aims to summarize our current understanding of molecular biomarkers that may be used to predict response to CRT in rectal cancer.     

Current status of and perspectives regarding neoadjuvant chemoradiotherapy for locally advanced esophageal squamous cell carcinoma

The significance of neoadjuvant chemoradiotherapy (NACRT) for esophageal squamous cell carcinoma (ESCC) remains controversial with regard to the pathological response and long-term survival. We herein review the current status of and future perspectives regarding NACRT followed by esophagectomy for locally advanced ESCC. Some studies have suggested that a pathological complete response with NACRT is more common in patients with ESCC than in those with adenocarcinoma and that NACRT provided a survival benefit limited to patients with ESCC. However, NACRT may increase the risk of postoperative complications after esophagectomy. It is obvious that a favorable pathological response is the most important factor for obtaining a survival benefit, although no established parameters have been implemented clinically to predict the response to NACRT. Prospective clinical studies and basic research studies to identify predictive biomarkers for the response to NACRT are needed to aid in the development of NACRT treatment strategies for patients with ESCC.     

Hedgehog信号通路相关蛋白在人胰腺癌SW1990耐药株中的表达及意义

目的:探讨Hedgehog信号通路蛋白在人胰腺癌吉西他滨耐药细胞株SW1990中的表达,为克服胰腺癌获得性耐药提供实验基础。方法:采用浓度梯度递增法建立人胰腺癌SW1990耐药株,采用噻唑蓝法测定SW1990亲代与耐药细胞IC50。实时荧光定量PCR检测亲代与耐药细胞mRNA中hedgehog信号通路成员Shh、SMO、Gli-1的表达差异。Western印迹法检测亲代与耐药细胞中上述蛋白质的表达。结果:人胰腺癌耐药株SW1990的IC50从亲代的(3.1±0.2)μmol/L提高到(232.2±12.3)μmol/L。荧光定量PCR结果显示耐药株中Shh、Gli-1的表达提高了(12.07±1.71)倍和(4.15±0.42)倍。亲代SW1990中未检测到SMO表达,而耐药细胞中却可以检测到SMO的表达。Western印迹结果同样显示,人胰腺癌SW1990耐药细胞株中高表达上述蛋白质。结论:人胰腺癌耐药株中高表达部分hedgehog信号通路蛋白。针对hedgehog信号通路的靶向治疗可能为克服胰腺癌耐药提供新的理论基础。     

乳腺癌p53，ki-67和bcl-2的表达与新辅助化疗的关系

目的 研究乳腺癌p53,ki-67和bcl-2基因蛋白表达与新辅助化疗临床效果的关系,以寻找指导治疗、判断预后的生物学指标.方法 采用免疫组化SABC法测定118例可手术的乳腺癌标本的p53,ki-67和bcl-2的蛋白表达,并分析其与新辅助化疗疗效的关系.结果 术前辅助化疗有效率为68.6%.p5 3表达阳性,化疗效果差（P＜0.05）;而ki-67阳性表达者有效率明显高于ki-67不表达者（P＜0.05）;bcl-2表达与疗效无明显关系.p53蛋白阳性表达者bcl-2表达下降.p53与ki-67蛋白表达有明显关系.结论 p53和ki-67蛋白表达可作为指导新辅助化疗及预后判断的分子生物学指标.     

The use of molecular markers as a method to predict the response to neoadjuvant therapy for advanced stage rectal adenocarcinoma

Aim The response to combined neoadjuvant therapy for advanced stage rectal adenocarcinoma is predictive of outcome. In addition to both clinical and pathological features, the expression of a variety of molecules may provide another method of identifying tumour responsiveness to pre‐operative therapy. The aim of this study was to evaluate several markers in the apoptotic pathway as well as expression of Cox‐2 and vascular endothelial growth factor (VEGF) to determine their ability to predict response to neoadjuvant therapy. Method In total, 152 patients with advanced rectal adenocarcinoma were treated with neoadjuvant therapy followed by resection. Paraffin‐embedded sections obtained before and after therapy were assessed by immunohistochemical staining for Cox‐2, VEGF, p53, p21, p27, Bax, BCL‐2 and apoptosis protease‐activating factor 1 (APAF‐1). These stains were correlated with tumour regression grade, complete pathological response and T‐downstaging of the surgical specimen. Clinical and pathological data were also collected. Data were analysed using the χ² and Spearman’s correlation tests. Results Pathological complete response was seen in 24.5% of patients. Amongst the apoptosis‐associated markers, only APAF‐1 expression was found to be significantly associated with tumour regression grade (P < 0.001), complete pathological response (P < 0.031) and T‐downstaging (P < 0.004). On multivariate analysis, APAF‐1 expression was found to be independently associated with good tumour regression grade. In contrast, overexpression of Cox‐2 and VEGF in pretreatment biopsies was related to less tumour regression (P < 0.003) and less likelihood of T‐downstaging (P < 0.03). Conclusion Immunohistochemical evaluation of initial biopsy specimens of rectal cancer with APAF‐1, Cox‐2 and VEGF may predict tumour response to neoadjuvant therapy in patients with advanced rectal adenocarcinoma. Those with an expected limited response may be considered for other investigational neoadjuvant protocols.