CK在Ⅰ期非小细胞肺癌患者淋巴结中的表达及其临床意义

目的通过检测Ⅰ期非小细胞肺癌(NSCLC)患者淋巴结中细胞角蛋白(CK)的表达,确定微转移灶的存在及其与肿瘤复发、转移和预后的关系。方法以CK作为肿瘤标记物,应用免疫组化链霉亲生物素-生物素-过氧化酶复合物(Streptavidin biotin-peroxidase complex,SABC)法,检测根治术后常规病理HE染色阴性的33例Ⅰ期NSCLC患者的246枚淋巴结中的微转移灶。结果33例患者246枚淋巴结中有10例(30.3%)患者的12枚(4.9%)淋巴结中CK阳性表达。有或无CK阳性表达的患者复发转移率差异有统计学意义(80.0%vs.26.1%,χ2=7.015,P=0.016),CK阳性表达患者的中位生存期显著短于CK阴性表达者(21个月vs.60个月,P=0.016);Cox单因素风险模型(P=0.004)和多因素风险模型(P=0.004)均显示存在淋巴结微转移的期NSCLC患者预后不良。结论CK免疫组化染色可以作为检测和判定肺癌淋巴结微转移的有效方法。CK免疫组化染色检测淋巴结微转移与Ⅰ期NSCLC复发转移相关,有助于更加精确的分期,可以作为Ⅰ期NSCLC患者根治术后的一个预后指标,并为其综合治疗提供理论依据。     

CD4+、CD8+和NK在结直肠癌中的表达及其与淋巴结微转移的关系

目的 检测不同Dukes分期结直肠癌患者淋巴结细胞角蛋白20(CK20)mRNA的表达及外周血CD4+、CD8+、CD4+/CD8+与NK细胞活性表达,探讨两者间关系.方法 采用常规苏木素.伊红(HE)染色病理切片检测21例结直肠癌患者281枚淋巴结转移癌灶及逆转录-聚合酶链反应(RT-PCR)方法检测患者淋巴结CK20 mRNA表达;采用流式细胞仪检测患者外周血CD4+、CD8+、CD4+/CD8+及NK细胞活性表达.结果 HE染色法检出有淋巴结转移者为16枚(6%,16/281),RT-PCR法检出有淋巴结转移者140枚(50%,140/281);按有淋巴结微转移重新Dukes分期后,手术前,A、B期患者血CD4+、CD4+/CD8+高于c期(P<0.05);A期患者血CD8+低于C期(P<0.05);B期患者血NK细胞活性高于C期(P<0.05).新Dukes分期与血CD4+呈负相关(r=-0.497,P<0.01);与CD4+/CD8+呈负相关(r=-0.714,P<0.01);与CD8+呈正相关(r=0.945,P<0.01).结论 RT-PCR方法对淋巴结微转移的检出率明显优于HE染色切片法,结直肠癌淋巴结微转移的发生与患者免疫功能明显低下密切相关.     

胰头癌淋巴结微转移与淋巴结分组关系的初步探讨

目的:探讨胰头癌淋巴结转移和微转移的分布特点,分析微转移与淋巴结分组、分站的关系,由此为确定胰十二指肠切除时的淋巴清扫范围提供理论依据.方法:以手术显微镜法分区域、完整收集并检出20例因胰头癌作区域性胰十二指肠切除术和扩大淋巴结清扫病例标本中的淋巴结,以苏木精-伊红染色和细胞角化蛋白(CK)染色检测淋巴结转移和微转移的发生.结果:在20例677枚淋巴结中,苏木精-伊红染色发现13例87枚淋巴结发生转移,CK染色发现57枚淋巴结存在微转移,总淋巴结转移病例数为16例(80%);微转移发生频率较高的为13组18.9%、14组14.2%、16组9.3%、11组8.6%、17组8.3%、9组4.2%、8组3.7%及12组3.0%;总淋巴结转移发生率较高的是:13组37.4%(46/123)、17组28.3%(13/46)、14组26.4%(37/140)、16组17.0%(18/1061、8组16.1%(10/621和6组14.7%(5/34).结论:胰头癌的淋巴结转移发生率甚高,微转移检测影响淋巴结的分组和分站,有助于明确临床分期;行胰头癌根治术时,应注重第13、17、14、16、8和6组淋巴结的清扫.     

D2—40／CKpan免疫组织化学双标记染色检测胃癌淋巴管癌栓及其临床意义

目的对比应用D2．40／CKpan免疫组织化学双标记染色（双标记）和苏木精一伊红染色检测胃癌淋巴管癌栓及其预后的临床意义。方法收集2001年1—12月间于解放军总医院病理科行胃癌根治术的108例进展期胃癌的组织蜡块，以苏木精．伊红染色为对照．评估D2．40／CKpan双标记对淋巴管癌栓的检出情况，并分析其与淋巴结转移及患者总体生存的关系。结果苏木精．伊红染色检出淋巴管癌栓57例（52．8％），D2—40／CKpan双标记检出淋巴管癌栓73例（67．6％），后者检出率明显高于前者（P=0．007）；苏木精．伊红染色中8例为假阳性，24例为假阴性。经苏木精-伊红染色评估的淋巴管癌栓不仅与淋巴结转移有关（P=0．024），还与患者的总体生存有关（P=0．043）；但经D2．40／CKpan双标记评估的淋巴管癌栓则与淋巴结转移及预后均无关（辟0．422和P=-0．402）。结论D2．40／CKpan双标记提高了淋巴管癌栓的检出率，但基于其评估的淋巴管癌栓与患者淋巴结转移及预后均无关。     

胃癌中血管内皮生长C的表达与淋巴结微转移的关系

目的研究胃癌组织中血管内皮生长因子C（VEGF-C）的表达及其与淋巴结转移及微转移的关系。方法选取67例胃癌患者组织标本,免疫组化技术检测胃癌组织中VEGF-C蛋白的表达．常规HE染色检测所有的淋巴结：在HE染色检查未发现癌转移灶的淋巴结标本中,免疫组化检测微转移病灶的存在情况。使用SPSS16．0统计软件分析VEGF—C与患者临床病理资料以及淋巴结微转移之间的关系。结果67例胃癌组织VEGF-C蛋白表达阳性46例（68．7％）。所有病例的淋巴结总数为902枚：HE染色检查未发现癌转移灶的淋巴结总数为358枚,免疫组化检出存在微转移病灶者16枚（4．5％）。有淋巴结转移组和微转移组的VEGF—C阳性表达率为81．3％（26／32）和88．9％（8／9）,分别高于无淋巴结转移组的57．1％（20／35）和无淋巴结微转移组的46．2％（12／26）,差异有统计学意义（P均〈0．05）。胃癌组织中VEGF—C的表达与患者年龄、性别、肿瘤大小、肿瘤位置、分化程度和浸润深度无相关性。结论胃癌组织中VEGF—C的高表达与淋巴结转移及微转移密切相关。     

中低位直肠癌新辅助放疗后系膜内淋巴结隐匿转移的临床病理学研究

目的探讨新辅助放疗后中低位直肠癌系膜内淋巴结隐匿转移及其与临床病理因素的关系。方法74例中低位直肠癌患者接受了新辅助放疗及全直肠系膜切除手术（TME）,术后应用脂肪清除技术获取全部淋巴结．将苏木精-伊红染色无淋巴结转移的标本进一步行抗CK抗体免疫组织化学（免疫组化）染色,检测淋巴结内肿瘤隐匿转移情况,并分析隐匿转移与临床病理因素之间的关系。结果74例标本共检出1883枚淋巴结．每例（25．4±1．3）枚。淋巴结常规病检发现172枚有转移（35例,占47.3％）,其直径（4．9＋2．6）mm,显著大于无转移淋巴结的直径（2．7±1．4）mm（P〈0．01）。对常规病检无转移的1711枚淋巴结进一步行抗CK抗体免疫组化检测．发现其中40枚（2．3％）有隐匿转移（24例,占32．4％）,隐匿转移淋巴结直径（3．2±1．2）mm,显著小于常规病理有转移的淋巴结（P〈0．01）。常规病检淋巴结无转移的39例患者有淋巴结隐匿转移者9例（23．1％）,明显低于常规病检淋巴结有转移者的淋巴结隐匿转移率（15／35,42．8％,P〈0．01）。ypN0期患者淋巴结隐匿转移与否对预后的影响差异无统计学意义（P=0．157）。结论对常规病检淋巴结无转移的直肠癌患者．存在淋巴结隐匿转移不应改变其N分期：不应将淋巴结隐匿转移单独作为TNM分期中对淋巴结转移情况的判断指标。     

超低位直肠癌新辅助治疗后淋巴结分布及转移规律

目的探讨新辅助治疗对超低位直肠癌淋巴结转移及其微转移规律及分布的影响,为手术方式的选择提供依据。方法运用大组织切片苏木精．伊红染色和组织芯片CK20染色方法,研究超低位直肠癌新辅助治疗组（21例）与直接手术组（23例）行Miles手术后的大体标本。结果新辅助治疗组21例患者直肠系膜共检获淋巴结138枚．其中转移淋巴结39枚,微转移12枚：7例为淋巴结癌转移。2例为淋巴结微转移,6例为病理完全缓解。直接手术组23例患者的直肠系膜共检获淋巴结415枚,其中转移淋巴结169枚,微转移59枚：12例为淋巴结癌转移,4例为淋巴结微转移。两组直肠系膜外带与前区的转移淋巴结分别占21．5％（11／51）与29．0％（49／169）、17．6％（9／51）与17．2％（29／169）。坐骨直肠窝转移淋巴结分别占该区总淋巴结的25．0％（3／12）与22．2％（8／36）,该区淋巴结转移或微转移者分别占总病例数的4．8％（1／21）与13．0％（3／23）。结论新辅助治疗影响超低位直肠癌区域淋巴结的转移与分布．新辅助治疗组肛门括约肌累及较直接手术组显著降低。坐骨直肠窝内极少发生淋巴结转移,Miles手术作为超低位直肠癌新辅助治疗后标准术式的价值应重新评估。     

术中美蓝染色及抗细胞角蛋白20检测淋巴结及其微转移在直肠癌患者中的临床应用

目的探讨术中经直肠上动脉注射美蓝行直肠系膜及淋巴结染色检测淋巴结及其微转移方法的临床意义。方法对30例行根治性手术治疗的直肠癌患者,术中经直肠上动脉插管注射美蓝6ml(美蓝染色组),使直肠系膜及各组淋巴结染色以统计淋巴结数目,同时行抗细胞角蛋白20(CK20)免疫组织化学(免疫组化)染色,检测其微转移情况;并与同期32例行直肠癌根治术患者术中常规手检法(常规手检组)检出的淋巴结数目进行对比。结果美蓝染色组肠旁淋巴结、肠系膜淋巴结、肠系膜根部淋巴结检出数目均明显多于常规手检组(P均=0.000)。美蓝染色组淋巴结常规病理检查阴性者,经CK20免疫组化染色,其转移阳性率增加17.7%;14例DukesB期患者(46.7%)经淋巴结CK20免疫组化染色需重新确定为DukesC期,11例患者(36.7%)出现跳跃淋巴结微转移现象。结论术中经直肠上动脉注射美蓝行淋巴结染色能提高淋巴结检出率。对常规病理检查阴性的淋巴结行CK20免疫组化染色检查其微转移灶,能提高淋巴结阳性检出率,使病理分期更准确。     

结直肠癌前哨淋巴结体外标本定位及其微转移免疫组化研究

目的探讨结直肠癌前哨淋巴结（SLN）体外定位技术方法及其可行性、准确性和临床价值。方法选择2003年3月至2003年10月间中山大学肿瘤防治中心腹科住院行根治手术的结直肠癌患者60例,62个肿瘤（2例患者为多原发）,进行体外SLN定位。标本离体后尽早进行异硫蓝SLN定位,传统病理检查阴性的SLN进行细胞角蛋白免疫组化检查。结果62例肿瘤成功检出SLN的59例,检出率95．2％。59例患者总共获得并检测1114枚淋巴结,平均每人18．9（4～46）枚。其中SLN157枚（14．9％）,平均每人2．7（1～9）枚。SLN敏感性39．1％（9／23）,假阴性率23．7％（14／59）,准确率76．3％（45／59）。50例SLN阴性的中有12例（24％）细胞角蛋白免疫组化检测阳性。36例HE和细胞角蛋白免疫组化检查全阴性者中4例（11．1％）SLN发现微转移灶。14例仅非SLN阳性中8例SLN发现微转移灶。结论结直肠癌异硫蓝SLN体外定位活检技术是可行的,结合免疫组化检测微转移可以提高术后分期,可以提高送检淋巴结个数,结合免疫组化技术,可以减少淋巴结转移漏诊发生率。但该方法假阴性率较高,不能完全取代常规淋巴结病理检查。     

CK19表达及其在结肠癌淋巴结微转移诊断中的应用

目的：研究用免疫组化方法检测CK19及其在结肠癌淋巴结微转移诊断中的应用与临床病理意义。方法：取材于50例结肠癌病人肿瘤组织及癌周淋巴结255枚,同时进行HE染色组织学检查和抗角蛋白19抗体的免疫组化检测。结果：50例结肠癌组织中CK19表达均为阳性。255枚淋巴结用HE染色检查阳性者56枚(22．0％),皆同时表达CK19阳性;另20枚淋巴结HE染色阴性,而CK19表达阳性。50例中有12例淋巴结中发现微转移,其中6例常规组织学检查属淋巴结转移阴性而免疫组化染色诊断表现为转移阳性。占常规病理检查淋巴结转移阴性者的21．4％(6／28)。随着肿瘤分期增加,淋巴结CK19表达阳性率亦增加。CK19表达阳性者预后较阴性者为差。结论：CK19免疫组化法是检测结肠癌淋巴结微转移的敏感而便捷的方法,而检测结肠癌微转移有助于判断肿瘤进展程度与预后。特别对在筛选组织学检查淋巴结阴性但存在微转移的病人有实用价值。     

Identification and evaluation of axillary sentinel lymph nodes in patients with breast carcinoma treated with neoadjuvant chemotherapy

Sentinel lymph node (SLN) biopsy has been shown to predict axillary metastases accurately in early stage breast cancer. Some patients with locally advanced breast cancer receive preoperative (neoadjuvant) chemotherapy, which may alter lymphatic drainage and lymph node structure. In this study, we examined the feasibility and accuracy of SLN mapping in these patients and whether serial sectioning and keratin immunohistochemical (IHC) staining would improve the identification of metastases in lymph nodes with chemotherapy-induced changes. Thirty-eight patients with stage II or III breast cancer treated with neoadjuvant chemotherapy were included. In all patients, SLN biopsy was attempted, and immediately afterward, axillary lymph node dissection was performed. If the result of the SLN biopsy was negative on initial hematoxylin and eosin-stained sections, all axillary nodes were examined with three additional hematoxylin and eosin sections and one keratin IHC stain. SLNs were identified in 31 (82%) of 38 patients. The SLN accurately predicted axillary status in 28 (90%) of 31 patients (three false negatives). On examination of the original hematoxylin and eosin-stained sections, 20 patients were found to have tumor-free SLNs. With the additional sections, 4 (20%) of these 20 patients were found to have occult lymph node metastases. These metastatic foci were seen on the hematoxylin and eosin staining and keratin IHC staining. Our findings indicate that lymph node mapping in patients with breast cancer treated with neoadjuvant chemotherapy can identify the SLN, and SLN biopsy in this group accurately predicts axillary nodal status in most patients. Furthermore, serial sectioning and IHC staining aid in the identification of occult micrometastases in lymph nodes with chemotherapy-induced changes.     

Cytokeratin is a superior marker for detection of micrometastatic biliary tract carcinoma

BACKGROUND: The incidence of lymph node micrometastases in patients with biliary tract carcinoma is unknown. We evaluated the utility of three antibodies for immunohistochemical (IHC) detection of micrometastatic disease in patients with gallbladder and bile duct carcinoma. MATERIALS AND METHODS: Surgical specimens from 35 patients with biliary tract carcinoma were evaluated. Histologically involved tissues were stained with the following antibodies using standard IHC techniques: cytokeratin (AE1:AE3), CEA (carcinoembryonic antigen), and EMA (epithelial membrane antigen). The antibodies with the greatest degree of positive staining were then used to evaluate the lymph nodes of patients with histologically negative lymph nodes. Micrometastatic disease was defined as clustered atypical cells <2 mm in size detected only with the use of IHC. RESULTS: All of the primary tumors and histologically positive lymph nodes demonstrated staining with cytokeratin and CEA antibodies, whereas only 83% were positive for EMA. Therefore, cytokeratin and CEA antibodies were used to evaluate histologically negative lymph nodes. Anti-cytokeratin immunostaining detected micrometastatic disease in two patients. Staining with anti-CEA was negative in all specimens. Overall, two of 15 patients with histologically node negative biliary tract carcinoma had occult micrometastases. CONCLUSION: Cytokeratin immunostaining enables detection of micrometastases in histologically negative lymph nodes in patients with biliary tract carcinoma. Prospective protocols incorporating cytokeratin staining of the lymph nodes may help determine the incidence and clinical significance of occult micrometastatic disease in these patients.     

胃下部癌常规病理阴性第11P组淋巴结微转移的研究

目的 检测胃下部癌患者常规病理阴性第11P组淋巴结微转移的情况,分析淋巴结微转移与临床病理因素的关系.方法 应用连续切片法和端粒酶重复扩增-ELISA方法 检测43例胃下部癌常规病理阴性的43枚第11P组淋巴结,结合临床病理资料进行统计学分析. 结果 本组43例胃下部癌患者常规病理阴性第11P组淋巴结经连续切片法检出有4例4枚淋巴结发生微转移,微转移发生率为9%;应用端粒酶重复扩增-ELISA法检测微转移发生率为44%,其中包括应用连续切片法检测出有微转移的4枚淋巴结.端粒酶重复扩增-ELISA法微转移检出率明显高于连续切片法(x 2 =13.07,P<0.05).胃下部癌第11P组淋巴结微转移与原发肿瘤大小(x 2 =8.488,P<0.05)、浸润深度(x 2 =6.473,P<0.05)及临床分期(x 2 =12.022,P<0.05)有关,与患者年龄、性别、大体分型、组织分化程度尤关.结论 胃下部癌常规病理阴性第11P组淋巴结中存在较高的微转移发生率,其微转移发生率与原发肿瘤大小、浸润深度及临床分期有关.     

Importance of missed axillary micrometastases in breast cancer patients

Axillary lymph node metastases dramatically worsen the prognosis of patients with breast cancer. Despite this prognostic significance, routine histologic examination of axillary lymph nodes examines less than 1% of the submitted material. It is therefore obvious that micrometastatic disease is missed with this rather cursory examination, and the question arises as to the significance of this missed disease. Most lines of evidence suggest that missed axillary micrometastases exist and contribute to patient mortality. Most large studies of breast cancer micrometastases have suggested that undetected axillary micrometastases can be identified with more detailed examinations of the regional lymph nodes and that this group of patients has a poorer prognosis than those with no metastases identified. In addition, small-volume nodal disease, too small to be detected by traditional hematoxylin and eosin staining, has been shown to be capable of producing tumors in animal models. Finally, micrometastases have been shown to be of significance in other diseases. This article reviews the lines of evidence and the ongoing studies that are attempting to clarify the significance of micrometastatic disease in patients with breast cancer.     

IHC和RT-PCR法对检测胃癌区域淋巴结微转移的价值及其意义

目的 探讨免疫组织化学方法(IHC)和逆转录聚合酶链反应(RT-PCR)两种方法对检测胃癌区域淋巴结微转移的临床价值及意义.方法 对85例胃癌根治性手术切除的淋巴结转移患者的临床资料进行了回顾性分析.共切取淋巴结1835枚,每例平均切除21.7枚.采用IHC和RT-PCR法检测细胞角蛋白20(CK20)的表达,研究淋巴结微转移与临床病理参数和预后的关系.结果 患者的淋巴结转移率经IHC法和RT-PCR法检测从HE染色的75.3%分别上升为83.5%和90.6%.经IHC和RT-PCR法检测重新分期率分别为18.8%和37.6%.淋巴结微转移的发生与肿瘤大小、部位无关·与肿瘤Lauren分型和浸润深度密切相关.82例完成随访,平均随访时间为21.2个月.微转移与预后无明显关系.结论 IHC和RT-PCR法是检测胃癌淋巴结微转移的有效手段,能准确判断临未分期,可为制定治疗方案提供依据.     

Detection of Micrometastatic Tumor Cells in pN0 Lymph Nodes of Patients With Completely Resected Nonsmall Cell Lung Cancer: Impact on Recurrence and Survival

OBJECTIVE: To detect occult micrometastatic tumor cells in pN0 lymph nodes of nonsmall cell lung cancer (NSCLC) by a combination of cytokeratin and p53 immunohistochemistry staining, and to evaluate the relation between the micrometastasis in pN0 lymph nodes and the prognosis of patients with completely resected stage 1 NSCLC. SUMMARY BACKGROUND DATA: The average 5-year survival rate for patients with completely resected stage 1 NSCLC is only about 70%; thus, about 30% of these patients have recurrent disease. This suggests that occult micrometastasis may exist at the time of surgery; the rate is clearly underestimated by current clinical staging examinations and conventional histopathologic methods. METHODS: A total of 474 hilar and mediastinal lymph nodes were removed during surgery from 49 patients with completely resected stage 1 NSCLC. The lymph nodes analyzed for micrometastasis using immunohistochemical staining with the biclonal anticytokeratin antibody, AE1/AE3. Of these 474 lymph nodes from 49 patients, 263 lymph nodes from 25 patients, whose primary tumors were positive for the p53 protein, were subjected to immunohistochemical staining with the monoclonal anti-p53 protein antibody DO-1. RESULTS: Cells positive for cytokeratin and p53 protein were found in 35 (7.4%) of 474 and 20 (7.6%) of 263 lymph nodes, respectively; 17 (34.7%) of 49 patients had cytokeratin-positive cells and 10 (40.0%) of 25 patients had p53-positive cells in their pN0 lymph nodes. By a combination of cytokeratin and p53 protein immunohistochemical staining, micrometastatic tumor cells were identified in pN0 lymph nodes in 22 (44.9%) of 49 patients. The patients with lymph node micrometastasis identified by a combination of cytokeratin and p53 protein immunohistochemical staining had a poorer prognosis than those without micrometastasis on both univariate and multivariate analyses (overall survival, P =.0003 and 0.013, respectively). CONCLUSIONS: The detection of lymph nodal micrometastasis by cytokeratin and p53 protein immunohistochemical staining will be helpful to predict the recurrence and prognosis of patients with completely resected stage 1 NSCLC.     

The use of cytokeratin staining in sentinel lymph node biopsy for breast cancer.

BACKGROUND: Controversy exists regarding the routine use of cytokeratin immunohistochemistry (IHC) in the histopathologic examination of breast cancer sentinel lymph nodes (SLN) because the clinical significance of micrometastases detected by IHC is unclear. This analysis was performed to determine the frequency of IHC-detected micrometastases. METHODS: All patients underwent SLN biopsy, followed by completion axillary dissection. This analysis included patients who had SLN evaluated by IHC. SLN were examined by hematoxylin and eosin (H&E) stain at 2-mm intervals, with IHC in 2 sections. The axillary dissection specimen was evaluated by routine H&E staining. RESULTS: IHC was performed in SLNs from 973 patients. Of the 869 patients with negative nodes by H&E, 58 (6.7%) were "upstaged" by IHC. In 6 of 58 patients (10.3%) who had IHC-only positive SLN, nodal metastases were found in the axillary dissection specimen. CONCLUSIONS: IHC resulted in upstaging of 6.7% of patients who had negative SLN on H&E staining. These patients had a 10.3% risk of residual axillary nodal metastases. However, the clinical significance of IHC-only positive SLN requires further study.     

Immunohistochemistry and molecular detection of nodal micrometastases in pancreatic cancer

PURPOSE: Assays based on polymerase chain reaction (PCR) demonstrate mutated Kiras in the regional nodes of a majority of patients with node-negative stage I or II (T(1-3), N(0), M(0)) pancreatic adenocarcinoma. The hypothesis that the presence of mutated Kiras equates with micrometastases has not been validated by detailed histologic examination nor has an impact on survival been demonstrated. METHODS: We examined the paraffin blocks of the primary tumor and regional lymph nodes from all 30 patients from 1984 to 1998 with resected pN(0) stage I or II pancreatic adenocarcinoma. DNA was analyzed for mutations in codon 12 of the Kiras oncogene by PCR and restriction digest with BstN1 (RFLP). All nodes were examined by histology of 4 hematoxylin and eosin-stained step sections and immunohistochemistry (HPE/IHC) with AE3/AE1 epithelial cell marker antibody. RESULTS: Examination of the regional lymph nodes of the 30 patients demonstrated nodal metastases in 9 (30%) by step-section histology alone, 14 (46.7%) by HPE/IHC, 19 (63.3%) by PCR/RFLP, and 25 (83.3%) by a combination of PCR/RFLP and HPE/IHC. Seven cases were HPE/IHC positive yet PCR/RFLP negative while 10 cases were PCR/RFLP positive and HPE/IHC negative. Median survival (months) did not differ if nodes were negative or positive by HPE/IHC (20.5 vs 17.5) or PCR/RFLP (20.0 vs 19.0) or a combination of these techniques (25 vs 18.5). CONCLUSIONS: A great majority (83.3%) of patients with pathologic stage I or II pancreatic cancer had metastases in their regional nodes. Step-sectioning with immunohistochemistry and PCR/RFLP are complementary tests in detection of metastatic cancer cells. Nodal micrometastases did not adversely influence survival.