Rb基因产物与胰腺癌的生物学特性及预后关系的研究

为了探讨Ｒｂ蛋白（ＰＲｂ），与胰腺癌的肿瘤生物学行为及临床预后的关系，应用抗Ｒｂ基因产物多克隆抗体（Ｒｂｃ－１５）对胰腺癌（７６例）和慢性胰腺炎（２３例）等进行免疫组化（ＡＢＣ法）染色。实验结果：ＰＲｂ阴性（即核染色缺乏）表达率在胰腺癌为３５．５％，淋巴结转移为５０％，明显高于在癌旁组织（１２．５％），慢性胰腺炎（８．７％）和正常胰腺（０％）的表达。ＰＲｂ阳性表达组的胰腺癌患者生存期明显高于阴性表达组。结果提示，ＰＲｂ的表达与胰腺癌的生物学特性及预后密切相关。     

胰腺星状细胞在胰腺癌组织中的激活及其可能的作用

目的：探讨胰腺星状细胞在胰腺癌组织中的表达及其可能作用。方法：应用免疫组化观察24例胰腺癌、3例慢性胰腺炎胰腺组织α－平滑肌肌动蛋白（α-smooth muscle acitn,α-SMA）和结蛋白（desmin）表达。结果：24例胰腺癌、3例慢性胰腺炎胰腺组织α－平滑肌肌动蛋白均为阳性表达，且胰腺癌胰腺组织阳性染色均强于慢性胰腺炎胰腺组织。24例胰腺癌胰腺组织结蛋白阳性表达率为83．3％，而在3例慢性胰腺炎 胰腺组织为0。结论：胰腺星状细胞可能在胰腺癌的发生、发展中起一定作用。     

Midkine在胰腺癌组织中的表达及临床意义

目的 探讨人胰腺癌组织中Midkine（MK）的表达及其与肿瘤细胞增殖的关系和意义。方法 免疫组织化学SP法检测49例胰腺癌、13例慢性胰腺炎及15例正常胰腺组织中MK和Ki67蛋白的表达。结果胰腺癌组织中MK和Ki67均高表达，阳性率分别为77．1％（35／49）、81．6％（40／49），二者的表达都与肿瘤组织学分级、临床分期和淋巴结转移有关（P〈0．05）。胰腺癌组织中Ki67表达显著高于慢性胰腺炎（3／13，P〈0．01）和正常胰腺组织（0／15，P〈0．01）。慢性胰腺炎和正常胰腺组织中未见MK阳性表达。胰腺癌组织中MK蛋白的表达与Ki67的表达呈正相关（r-0．4，P〈0．05）。结论 检测MK蛋白对于胰腺癌的诊断及与慢性胰腺炎的鉴别诊断具有参考价值。MK在胰腺癌中高表达可能与肿瘤的发生发展及细胞增殖密切相关。     

RUNX3、CyclinDl在胰腺癌组织中的表达及临床意义

目的检测RUNX3、CyclinDl蛋白在胰腺癌组织中的表达,分析其临床意义。方法采用免疫组化sP法检测47例胰腺癌、18例胰腺囊腺瘤及12例正常胰腺组织中RUNX3和CyclinDl蛋白的表达,分析它们与临床病理参数间的关系。结果胰腺癌、胰腺囊腺瘤和正常胰腺组织的RUNX3蛋白阳性表达率分别为57．4％（27／47）、94．4％（17／18）、100％（12／12）;CyclinDl蛋白阳性表达率分别为72．3％（34／47）、44．4％（8／18）、8．3％（1／12）。胰腺癌RUNX3阳性表达与患者性别、年龄无关,与胰腺癌的临床分期、淋巴结转移、分化程度呈负相关（P〈0．05）。CyclinDl阳性表达与患者性别、年龄无关,与胰腺癌临床分期、淋巴结转移、分化程度呈正相关（P〈0．05）。胰腺癌组织RUNX3与CyclinDl的表达呈负相关（r=-0．375,P=0．009）。结论胰腺癌组织中RUNX3呈低表达,Cyclin D1呈过表达,它们均与胰腺癌的发生、发展有关。     

大肠癌P53蛋白PCNA和CEA的表达与淋巴结转移的关系

目的研究大肠癌Ｐ５３蛋白、增殖细胞核抗原（ＰＣＮＡ）和ＣＥＡ的表达与淋巴结转移的关系．方法应用链霉菌素生物素（ＳＰ）免疫组化法，观察４４例大肠癌Ｐ５３，ＰＣＮＡ的阳性率和ＣＥＡ的表达型式．结果大肠癌Ｐ５３阳性率为５２３％；大肠癌Ｐ５３阳性表达与性别、年龄及肿瘤的部位、分化程度和浸润深度无关（Ｐ＞００５）；大肠癌Ｐ５３阳性者其淋巴结转移率较阴性者高（１４／２３，６０９％ｖｓ６／２１，２８６％，Ｐ＜００５）；Ｐ５３阳性表达及有淋巴结转移者其细胞增殖活性分别较Ｐ５３阴性表达及无淋巴结转移者高（５５９±１７ｖｓ３７９±１４，Ｐ＜００５；５６２±１５ｖｓ３９６±１７，Ｐ＜００５）；Ｐ５３阳性表达及有淋巴结转移者其ＣＥＡ表型均以胞质型和间质型为主（２１／２３，９１３％ｖｓ１３／２１，６１９％，Ｐ＜００５；１９／２０，９５０％ｖｓ１５／２４，６２５％，Ｐ＜００５）．结论检测Ｐ５３和ＰＣＮＡ表达及ＣＥＡ表型对判断大肠癌的恶性程度，预测其淋巴结转移趋势和预后及指导临床治疗有重要价值．     

胰腺超声内镜细针穿刺活检组织中粘蛋白表达检测辅助诊断胰腺癌的价值评价

目的 检测粘蛋白（MUCl、MUC2、MUC5AC）在胰腺超声内镜细针穿刺（EUS-FNA）组织标本中的表达，评价其对胰腺癌辅助诊断的价值。方法 收集54例胰腺占位病变的EUS-FNA组织标本，采用S-P免疫组化法检测粘蛋白（MUCl、MUC2、MUC5AC）的表达，根据临床综合判断的诊断，与细胞学检查结果比较，评价其诊断价值。结果 54例患者最后确诊为胰腺癌38例，胰腺良性肿瘤6例，慢性胰腺炎10例。细胞学和组织学的诊断敏感性分别为31．6％和47．4％。MUC1、MUC2、MUC5AC在胰腺癌EUS-FNA标本组织中的阳性表达率为81．6％（31／38）、10．5％（4／38）、84．2％（32／38），在胰腺良性疾病组织标本中分别25％（4／16）、31．3％（5／16）、43．8％（7／16），其中MUCl和MUC5AC两组间差异有统计学意义（P〈0．01）。MUCl的表达与胰腺癌的临床分期、淋巴结转移呈正相关。将细胞组织学检查结合MUCl和MUC5AC表达检测诊断胰腺癌的敏感性可提高至89．5％。结论胰腺EU$-FNA组织标本中MUCl、MUC5AC的检测对胰腺癌有临床辅助诊断价值，且MUCl还能预测胰腺癌的临床分期及淋巴结转移。     

胰腺癌组织中Syk的表达及意义

目的探讨胰腺癌组织中脾酪氨酸激酶（Syk）的表达情况及意义。方法用免疫组化法和RT-PCR检测40例胰腺癌组织、9例慢性胰腺炎、8例正常胰腺组织中的Syk蛋白及其mRNA,形态计量学图象分析法测定微淋巴管密度（MLVD）。结果Syk蛋白在胰腺癌、慢性胰腺炎和正常胰腺组织中阳性率分别为27.5%、77.8%和100%;Syk蛋白与胰腺癌TNM分期、分化程度和淋巴结转移有关（P〈0.05）。Syk mRNA在胰腺癌中呈低表达（P〈0.01）。胰腺癌组织中微淋巴管密度（MLVD）在TNM分期III-IV期组显著高于I-II期组（P〈0.05）,淋巴结转移阳性组显著高于阴性组（P〈0.01）。Syk蛋白阴性表达者的MLVD显著高于阳性组（P〈0.01）。结论Syk在胰腺癌中表达减低或缺失,与胰腺癌的发展显著相关。     

胰腺癌环氧合酶-2表达的意义

目的研究胰腺癌中COX-2表达的意义．方法应用免疫组化SP法检测82例胰腺癌、22例慢性胰腺炎、9例胰腺良性肿瘤、15例正常胰腺组织和2株人胰腺癌细胞中COX-2的表达,然后比较胰腺癌组织COX-2表达与胰腺癌患者临床病理特征的关系。结果2株人胰腺癌细胞COX-2表达均阳性。70．7％（58／82）胰腺癌组织可见COX-2表达,而正常胰腺组织只有6．7％（1／15）呈微弱表达。COX-2在4种组织中的表达程度有显著性差异（P〈0．001）。胰腺癌组织COX-2表达显著高于其他3种组织（P〈0．05）。胰腺癌组织COX-2表达水平的高低与胰腺癌的临床病理特征无关（P〉0．05）。结论COX-2蛋白的检测对胰腺癌的诊断及其与胰腺良性肿瘤、慢性胰腺炎的鉴别诊断有帮助。胰腺癌组织COX-2表达不能作为预测患者预后的指标。     

无嘌呤嘧啶核酸内切酶在胰腺癌组织的表达及其临床意义

目的 研究胰腺癌组织APE的表达及其与临床肿瘤指标的关系。方法 （1）通过逆转录-聚合酶链反应（RT-PCR）方法检测4株胰腺癌细胞株APE mRNA的表达；（2）收集37例手术切除的胰腺癌及12例相应癌旁胰腺组织石蜡标本，应用EnVision免疫组化法分别检测癌组织和癌旁胰腺组织APE的表达情况。结果 4株胰腺癌细胞株均有APE mRNA表达；37例胰腺癌中APE阳性表达33例（89．2％），其中APE胞核阳性表达7例（21．2％），胞质阳性表达5例（15．2％），胞质及胞核均表达21例（63．6％）。12例癌旁胰腺组织导管及腺泡呈阴性表达，胰岛胞质呈阳性表达，胰腺上皮内瘤变呈胞核阳性表达。APE阳性率与肿瘤分化程度，肿瘤大小、淋巴及远处转移无关（P〉0．1）。结论 APE在胰腺癌组织中有较高的阳性表达率，检测其定位的特异性表达可能有助于胰腺癌的早期诊断。     

胰腺癌组织表皮生长因子mRNA表达的意义

目的探讨ＥＧＦｍＲＮＡ的表达与胰腺癌发生、发展及预后的关系．方法应用Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交方法，检测胰腺癌２７例和正常胰组织７例中ＥＧＦｍＲＮＡ表达．结果正常胰腺组织７例未检测到ＥＧＦｍＲＮＡ表达，胰腺癌２７例ＥＧＦｍＲＮＡ阳性表达率６６７％（１８例），经卡方检验发现，ＥＧＦｍＲＮＡ表达与胰腺癌病理分级、临床分期及伴随局部淋巴结转移呈显著相关（Ｐ＜００５）．结论ＥＧＦｍＲＮＡ表达与胰腺癌发生有关，胰腺癌ＥＧＦｍＲＮＡ表达可作为胰腺癌预后的参考指标     

Mucin4在胰腺癌组织中的表达及其临床意义

目的研究胰腺癌组织中Mucin 4(MUC4)的表达及其与临床病理参数间的关系。方法(1)采用ABC免疫组织化学方法检测35例胰腺癌、12例胰腺良性肿瘤及5例慢性胰腺炎组织MUC4的表达。(2)通过RT-PCR方法检测12例胰腺癌组织、癌旁胰腺组织以及2株胰腺癌细胞株MUC4 mRNA的表达。结果 (1)35例胰腺癌组织中MUC4蛋白阳性表达24例,12例胰腺良性肿瘤中MUC4蛋白阳性表达2例,5例慢性胰腺炎组织中MUC4蛋白均为阴性。MUC4蛋白胰腺癌组织中阳性表达率显著高于胰腺良性肿瘤及慢性胰腺炎组织(P<0．05)。MUC4在胰腺癌组织中阳性表达率与肿瘤的部位、淋巴结转移、临床分期无关(P>0．05)。(2)12例胰腺癌组织中MUC4 mRNA表达阳性有6例,癌旁组织中无阳性表达,2株胰腺癌细胞株均呈阳性表达。MUC4 mRNA在胰腺癌组织中阳性表达率显著高于癌旁组织(P<0．05)。结论 MUC4在胰腺癌中有较高的表达率,检测其表达可能有助于胰腺癌的诊断,并可作为鉴别胰腺癌和慢性胰腺炎一个重要参考指标。     

Determination of CA 19-9 antigen in serum and pancreatic juice for differential diagnosis of pancreatic adenocarcinoma from chronic pancreatitis

Serum CA 19-9 levels were measured in 63 patients with ductal pancreatic adenocarcinoma and in 49 patients with chronic pancreatitis. Concentrations were abnormally high (greater than 40 U/ml) in 57 (90%) patients with cancer and only in 5 (10%) patients with chronic pancreatitis. All patients with falsely normal serum values had poorly differentiated carcinomas. Median CA 19-9 concentrations were progressively higher in patients with more advanced cancer. Fifteen of 16 (93%) patients with localized cancer has abnormal serum levels but only 5 (31%) of them had values greater than 120 U/ml, which was the highest score observed in patients with chronic pancreatitis. Pure pancreatic juice was obtained endoscopically from 23 patients with pancreatic cancer and from 20 with chronic pancreatitis. CA 19-9 concentrations in pancreatic juice were significantly higher in patients with cancer than in non-neoplastic patients. All 11 patients with resectable cancer investigated had a ratio of CA 19-9 to secretory protein concentration in pancreatic juice above the range of patients with chronic pancreatitis. We conclude that serum CA 19-9 determination is highly sensitive and specific for the differential diagnosis of pancreatic cancer versus chronic pancreatitis. However, moderately increased values (less than 120 U/ml), as seen in patients with localized pancreatic adenocarcinoma, are not conclusive for malignancy. The measurement of CA 19-9 to total protein ratio in pure pancreatic juice is proposed as an adjunctive, accurate diagnostic marker for early stages of pancreatic adenocarcinoma.     

胰腺癌HMGB1表达及其与血行转移的关系研究

目的 探讨人胰腺癌高迁移率族蛋白B1(hiish mobility group protein B1,HMGB1)表达及其与血行转移的关系.方法 应用Western blot法检测68例胰腺癌患者、18例CP和21例健康者血清HMGB1水平,并对其中37例胰腺癌患者手术前后的血清HMGB1水平进行比较;应用免疫组织化学法检测67例胰腺癌组织HMGB1和CD31的表达.结果 胰腺癌、CP及健康者血清HMGB1水平分别为(119.7±54.5)ng/ml、(40.2±25.5)ng/ml和(13.1±4.3)ng/ml,相差非常显著(P<0.001).胰腺癌患者术后血清HMGB1水平为(69.3±5.1)ng/ml,显著低于术前的(120.2±8.2)ng/ml(P<0.001).胰腺癌组织HMGB1表达阳性率为43.6%,HMGB1表达与组织分化、TNM分期及转移有关,P均<0.01;HMGB1表达与血管密度呈显著正相关(r=0.76,P<0.0001),免疫组化显示,HMGB1表达阳性的肿瘤细胞多位于有腔血管周围,位于血管内的肿瘤细胞HMGB1阳性表达率为71%.结论 胰腺癌患者HMGB1呈高表达,表达HMGB1的肿瘤细胞易于进入血管内,与其血行转移有关.     

Increased angiogenin expression in obstructive chronic pancreatitis surrounding pancreatic cancer but not in pure chronic pancreatitis

We previously demonstrated the increased expression of angiogenin (ANG) in pancreatic cancer and its relation to cancer aggressiveness; however, the expression patterns and the roles of angiogenin in chronic pancreatitis are still unknown. We investigated the expression of ANG both in the tissues and in the sera of chronic pancreatitis patients (pure chronic pancreatitis) by using in situ hybridization, Western blot analysis, and enzyme-linked immunosorbent assay. In situ hybridization revealed no detectable ANG messenger RNA (mRNA) signals in all tissues of pure chronic pancreatitis and normal pancreas. Only a small amount of protein band expression was obtained in all of the protein lysates of pure chronic pancreatitis and normal pancreas. Accordingly, there was no significant difference between the mean serum ANG concentration of chronic pancreatitis patients (352.1+/-72.5 ng/ml) and that of healthy volunteers (357.6+/-45.2 ng/ml). By contrast, acinar cells and interstitial fibroblasts in the tissues surrounding pancreatic cancer showed increased ANG mRNA expression. Strong protein band expression was obtained in the protein lysates of pancreatic cancer surrounding tissue, and mean serum ANG concentration was increased in pancreatic cancer patients. These findings suggest that ANG expression is increased in pancreatic cancer surrounding tissue but is not increased in pure chronic pancreatitis, and that ANG is potentially involved in the pancreatic cancer microenvironment rather than the establishment of pure chronic pancreatitis.     

LH-RH receptors in the human pancreas. Basis for antihormonal treatment in ductal carcinoma of the pancreas.

LH-RH-, estrogen-, and progesterone-receptor binding was measured in the human pancreas of patients with ductal pancreatic cancer (n = 23) and chronic pancreatitis (n = 15), and of organ donors (n = 11). Receptor analysis was determined by incubation of the homogenized tissues with estrogen, progesterone, and the LH-RH analog buserelin labeled with iodine-125. Only one biopsy (9%) from normal pancreas had an LH-RH-receptor concentration greater than 3 fmol/mg membrane protein. LH-RH binding levels greater than 3 fmol/mg were detected in 67% of patients with chronic pancreatitis and in 57% of patients with pancreatic cancer. Progesterone levels greater than 15 fmol/mg membrane protein were found in 36% of normal pancreas, in 27% of chronic pancreatitis, and in 17% of pancreatic cancer cases, respectively. The highest concentration of estrogen receptors (greater than 15 fmol/mg membrane protein) was seen in normal pancreas (73%). The increase in LH-RH-receptor concentration in chronic pancreatitis and pancreatic cancer seems to be unspecific, but might be of benefit for antiproliferative treatment in pancreatic cancer.     

Ki-ras codon 12 point mutation and p53 mutation in pancreatic diseases.

BACKGROUND/AIMS: The Ki-ras gene located at 12p, encodes the GTP binding protein involving the signal transduction system and concerns cell proliferation and differentiation. METHODOLOGY: Pancreatic tissues were obtained from 37 patients with various pancreatic diseases. Ki-ras codon 12 point mutation and p53 (exon 5-8) mutation were examined in 3 patients with chronic pancreatitis, 9 mucinous adenoma of the pancreas (2 with mucinous cystadenoma and 7 with intraductal papillary-mucinous adenoma), 22 pancreatic ductal carcinoma, and 3 serous cystadenoma. RESULTS: On usual pancreatic exocrine ductal lesions, Ki-ras point mutation was evident in 0% (0/3) of chronic pancreatitis, in 56% (5/9) of mucinous adenoma, and in 57% (12/21) of ductal carcinoma, the mutation being located in the second letter in 18 and in the 1st letter in 2. One Ki-ras codon 12 positive pancreatic cancer showed Ki-ras codon 12 point mutation in the surrounding pancreas (2nd letter mutation in both areas). p53 mutation was present in 0% (0/1) of chronic pancreatitis, in 0% (0/8) of mucinous adenoma, while it was evident in 29% (6/21) of pancreatic ductal carcinoma, the mutation being situated in exon 5 in 3, in exon 6 in 1, and in exon 7 in 2. In 3 patients with serous cystadenoma, there was no mutation in Ki-ras codon 12 or p53 (exon 5-8). CONCLUSIONS: These findings suggest that Ki-ras point mutation is involved in the early events of pancreatic ductal carcinoma, while p53 mutation is intricated in the late phase of pancreatic ductal carcinogenesis and the histogenesis of serous cystadenoma is different from that of pancreatic exocrine ductal lesions including mucinous adenoma and ductal carcinoma.     

谐波造影增强内镜超声对胰腺癌与局灶型胰腺炎的鉴别诊断价值

目的 探讨谐波造影增强内镜超声（CH-EUS）对胰腺癌与局灶型胰腺炎鉴别诊断的价值.方法 选择上海长海医院经CH-EUS检查诊断为胰腺癌和局灶型胰腺炎患者,以内镜超声引导下细针穿刺术（EUS-FNA）或组织病理学及6个月以上随访结果作为最终诊断,评价CH-EUS对胰腺癌与局灶型胰腺炎的鉴别诊断效果,并分析两者的CH-EUS图像特征.结果 共有56例患者入选本研究,平均年龄（56±12）岁.最终诊断局灶型胰腺炎21例,胰腺癌35例.CH-EUS显示的正常胰腺组织增强时相与周围组织同步,达峰显著,呈均匀等增强.胰腺癌增强时相多数晚于正常胰腺组织,消退快,达峰不显著,94.3％ （33/35）的病灶内部呈不均匀低增强,1例高增强者为癌肿内部有较多高强化的分隔,1例均匀等增强者为慢性胰腺炎癌变.局灶型胰腺炎增强多数表现为与正常胰腺组织等时相,达峰显著,76.2％（16/21）呈均匀等增强.CH-EUS鉴别局灶型胰腺炎与胰腺癌的灵敏度为90.5％,特异度97.1％,准确率94.6％,阳性预测值95.0％,阴性预测值94.4％,阳性似然比31.7,阴性似然比0.1.结论 CH-EUS可以实时、清晰地显示胰腺肿瘤的血供情况,能对胰腺癌和胰腺局灶型炎症的鉴别诊断提供有力帮助,是一种有价值的临床诊断新方法.     

胰腺癌p57~(kip2)、视网膜母细胞瘤蛋白和增殖细胞核抗原的表达及与临床病理的关系

目的 探讨细胞周期蛋白依赖性激酶抑制因子p57~(kip2),视网膜母细胞瘤蛋白(Rb)和增殖细胞核抗原(PCNA)在胰腺癌发生发展中的作用。方法 应用免疫组化技术,对32例胰腺癌及癌旁组织中p57~(kip2)蛋白和PCNA表达进行检测。结果 p57~(kip2)蛋白阳性表达率在胰腺癌组织中为46.9％,显著低于癌旁胰腺组织的75.0％(x~2=5.317,P<0.05),并与胰腺癌组织分化程度有关(P<0.05),而与淋巴结转移无关(P>0.05)。Rb蛋白阳性表达率在胰腺癌组织中为50％,显著低于癌旁胰腺组织的78.1％(x~2=5.497,P<0.05)。PCNA阳性表达率在胰腺癌组织中为71.9％,显著高于癌旁胰腺组织的43.8％(x~2=5.189,P<0.05),并与胰腺癌组织分化程度和淋巴结转移均有关(P<0.05)。p57~(kip2)蛋白阳性表达组Rb蛋白阳性表达率为53.3％;p57~(kip2)蛋白阴性表达组Rb蛋白阳性表达率为47.1％,两组间无相关性(γ=0.16507,P>0.05)。结论 P57~(kip2)、Rb蛋白低表达和PCNA蛋白过度表达与胰腺癌的发生发展有关。     

Real-time quantitative PCR of telomerase mRNA is useful for the differentiation of benign and malignant pancreatic disorders

The presence of telomerase activity has been proposed as a specific and sensitive marker for malignant tissue, and positivity rates of up to 95% have been reported in pancreatic cancer. In the present study telomerase activity analysis was reevaluated in 29 pancreatic cancer tissues compared with 36 chronic pancreatitis tissues and 21 normal controls, and a study was made of whether malignant and benign pancreatic disorders can be better differentiated using a novel technique real-time quantitative PCR analysis-analyzing telomerase mRNA expression. Telomerase activity was present in 35% (10 of 29) of pancreatic cancer samples, 3% (one of 36) of chronic pancreatitis samples, and none of the normal pancreatic tissue samples in the TRAP assay. Real-time quantitative PCR analysis revealed the presence of telomerase mRNA expression in 50% (10 of 20) of normal, 86% (31 of 36) of chronic pancreatitis, and 90% (26 of 29) of pancreatic cancer samples. However, quantification of the expression data revealed that the relative increase above normal was 5.5 (range, 3.5-8.6) for chronic pancreatitis and 23.9 (range, 18.6-30.7) for pancreatic cancer samples (p < 0.01). No relationship was found between telomerase activity and the fold increase of telomerase mRNA above normal and gender, patient age, tumor stage, or tumor grade. These data indicate that detection of telomerase activity using the TRAP assay has limitations in differentiating benign and malignant pancreatic disorders. However, telomerase mRNA analysis by real-time quantitative PCR analysis allows a highly sensitive detection and differentiation of pancreatic cancer from normal pancreas and chronic pancreatitis and thereby may serve as a new reliable, easy, and effective diagnostic tool for cancer diagnosis.