Human leukocyte antigens as genetic markers in Greek patients with sporadic pancreatic cancer.

PURPOSE: In this study we investigated the relationship between specific HLA antigens and sporadic pancreatic cancer in Greek population. METHODS: The allele frequencies of serologically and molecular defined class I and II HLA antigens were studied in 60 unrelated patients with pancreatic cancer histologically confirmed. The results obtained for HLA frequencies were compared with those of 105 healthy control subjects (control group). RESULTS: Increased frequencies of HLA-A30 (16.7 vs. 3.8%; P < 0.01; OR = 5.05), A31 (9.5 vs. 1.9%; P < 0.05; OR = 5.72), B18 (31.7 vs. 14.3%; P < 0.05; OR = 2.78) and Cw7 (53.3 vs. 21.9%; P < 0.01; OR = 4.07) were observed in patients with pancreatic cancer in comparison to the control subjects. CONCLUSIONS: This study demonstrates the association between specific HLA antigens and pancreatic cancer development in whites and suggests a genetic susceptibility factor for the disease.

Co-expression of trypsin and tumour-associated trypsin inhibitor (TATI) in colorectal adenocarcinomas.

Trypsin and its specific inhibitor, TATI (tumour-associated trypsin inhibitor), are expressed in normal human pancreas and in a variety of tumours. The aim of the present study was to assess the parallel expression of trypsin and TATI in colorectal cancer, in comparison with their expression in normal epithelial tissue, since proteases and their inhibitors are thought to be co-expressed in malignant neoplasms. We also assessed the possible significance of their expression as a means of differentiation between normal and malignant tissue. We examined qualitatively and semi-quantitatively the immunohistochemical expression of trypsin and TATI on paraffin-embedded serial tissue sections from 91 colorectal adenocarcinomas. The reverse-transcriptase-polymerase-chain reaction (RT-PCR) was also performed on fresh malignant tissue from 55 of the above adenocarcinomas. Normal and non-malignant tissues adjacent to the tumours were also evaluated. Cytoplasmic expression of trypsin (more than 25% of the cancer cells positive) was found in 67 (73.6%) adenocarcinomas, whereas TATI was expressed in the cytoplasm of 59 (64.8%) cases studied. Statistical analysis using Spearman's test has demonstrated a significant correlation between trypsin and TATI immunohistochemical expression (p<0.01). RT-PCR showed co-expression of trypsin and TATI mRNA in all carcinomas studied. Distinct patterns of trypsin and TATI immunohistochemical expression were observed in adjacent, non-malignant tissues, where both trypsin and TATI mRNA were also detected. Normal tissues were negative by immunohistochemistry. Our results indicate co-expression of trypsin and TATI in colorectal tumours both at the mRNA and protein level. We conclude that in colorectal neoplasms, high levels of trypsin and TATI may be important for malignant tumour formation and/or metastatic process.

P53 and C-FOS overexpression in patients with thyroid cancer: an immunohistochemical study.

A sequence of genetic events characterized by deletion and expression of several oncogenes may lead progressively to tumorgenesis. The expression of certain oncogenes is believed to be related with thyroid carcinogenesis and tumor progression. We investigated immunohistochemically p53 tumor suppressor gene and c-fos oncogene expression in forty patients with thyroid cancer. Thyroid biopsies from twenty patients with benign thyroid diseases were also examined. The forty patients with thyroid cancer varied histologically; 24 with papillary carcinoma (60%), 12 with follicular carcinoma (30%), 3 with anaplastic carcinoma (7.5%) and one with medullary carcinoma (2.5%). The patients with benign thyroid diseases consisted of 10 with adenomatous goiter (50%), 7 with goiter (35%) and three with Hashimoto thyroiditis (15%). Individual p53 and c-fos expression was more prevalent in thyroid carcinomas compared to benign tumors (p=0.001 and p=0.04, respectively). A marked increase of p53 and c-fos coexpression was found (p=0.02) in patients with thyroid cancer and metastasis to the regional lymph nodes. Furthermore c-fos was overexpressed in only female thyroid cancer patients. In conclusion, p53 and c-fos are significantly overexpressed in thyroid cancer patients, indicating their role in the genetic mechanisms leading to thyroid tumorigenesis. This hypothesis is further supported by the observation that p53/c-fos coexpression was related with more advanced disease status.

Incidental finding of gallbladder carcinoma detected during or after laparoscopic cholecystectomy.

AIM: Carcinoma of the gallbladder is a rare neoplasm with a dismal prognosis. With the increase of cholecystectomies due to the wide acceptance of laparoscopic cholecystectomy, the incidental diagnosis of gallbladder carcinoma is more frequent. We report our experience with gallbladder cancer diagnosed during or after the performance of laparoscopic cholecystectomy. METHODS: We evaluated 11 patients with gallbladder cancer out of 5539 patients who underwent laparoscopic cholecystectomy. Patient clinical and demographic characteristics were reviewed. RESULTS: Intraoperatively in 297 patients there was the suspicion of adenocarcinoma and frozen sections were performed. In four of them the diagnosis of adenocarcinoma was confirmed. In two of them the procedure was converted to open with gallbladder liver bed resection and regional lymph node dissection while the other two were considered inoperable. Of the remaining 5242 patients, seven were diagnosed postoperatively at the pathologic examination. Of these, five patients refused to undergo a repeat operation. We did not observe port site metastasis in any of our patients. Survival was low and ranged from 3-14 months. CONCLUSION: Gallbladder cancer runs a short course, with a poor prognosis. The use of a meticulous laparoscopic technique seems to be important for the diagnosis and the avoidance of early complications of the disease.

Surgical adjuvant therapy of rectal carcinoma: a controlled evaluation of leucovorin, 5-fluorouracil and radiation therapy with or without interferon-alpha2b.

BACKGROUND: The aim of this study was to determine whether the efficacy of the combination of 5-fluorouracil (5-FU), leucovorin (LV) and radiation therapy (RT) could be improved by the addition of interferon-alpha2b (IFN-alpha) in patients who have had a 'curative' resection, for rectal adenocarcinoma (Dukes' B2/C; T3 N0, T4 N0, N1-3). PATIENTS AND METHODS: A total of 207 eligible patients with a performance status of 0 or 1 were randomized postoperatively between days 21 and 70 to one of the two treatment groups: group A, LV 20 mg/m2 i.v. bolus and 5-FU 425 mg/m2 i.v. days 1-5 and 29-33, LV 20 mg/m2 and 5-FU 400 mg/m2 days 57-60 and 85-88, LV 20 mg/m2 and 5-FU 380 mg/m2 days 1-5 and 29-33 with the second day 1 occurring 28 days after the completion of RT (45 Gy); group B, LV, 5-FU and RT as in group A, and IFN-alpha 5 x 10(6) IU s.c. three times during each week chemotherapy is given. RESULTS: 104 patients were randomized into group A and 103 into group B. There was no statistically significant difference in either disease-free survival or overall survival between the two groups. Toxicity was also the same, except for the flu-like syndrome associated with the IFN-alpha administration. CONCLUSIONS: There was no difference in efficacy between the two combinations. Toxicity was greater with the LV + 5-FU + IFN-alpha regimen because of the flu-like syndrome.

Common prognostic factors for stage III melanoma patients and for stage I and II melanoma patients with recurrence to their regional lymph nodes.

This study was undertaken in order to identify the prognostic factors for stage III malignant melanoma patients. In addition we compared the survival data of these patients with data from patients presenting with stage I and II disease who subsequently developed a regional nodal recurrence, in order to identify common prognostic factors and to compare the biological behaviour of the two groups. We retrospectively examined two groups of patients. The first consisted of 116 patients with stage III malignant melanoma and the second consisted of 57 patients with stage I and II malignant melanoma that were found to have regional lymph node metastases diagnosed at least 6 months after surgical treatment of their primary lesion. The age of the patients, the number of disease-involved lymph nodes, the site of the primary lesion and the presence or not of palpable lymph nodes proved to be significant prognostic factors of the first group. We also analysed the survival data of the second group and compared it with data from the stage III patients. The 5 year survival starting from the time after diagnosis of the primary lesion was 47.37% compared with 25.86% in stage III patients; however, this difference was not statistically significant. Patients who present with stage III malignant melanoma seem to have a more aggressive phenotype than stage I and II malignant melanoma patients who present with recurrent disease in their regional lymph nodes. Disease behaviour is dictated by the number of disease-involved lymph nodes, the site of the primary lesion and the type of surgical procedure performed (elective or therapeutic lymph node dissection).

Latent adenocarcinoma of the colon discovered during or after laparoscopic cholecystectomy.

BACKGROUND: The wide acceptance of laparoscopic cholecystectomy has resulted in the performance of increased numbers of cholecystectomies, hence increasing the number of patients discovered with concomitant malignancy or other pathological states. PATIENTS AND METHODS: A total of 3751 patients who underwent laparoscopic cholecystectomy between January 1995 and December 2000 were included in this study. Nine cases of coexisting malignant colonic neoplasm were discovered. All of these patients but one underwent therapeutic resection. RESULTS: The survival rate of these nine patients was the same as that of 62 consecutive colonic cancer patients who were treated in our department over the same period. The rate of postoperative complications in the study group was higher than in the control group (21 % vs. 9.5 %). The hospital stay in these patients was also greater (17 days vs. 10 days). CONCLUSION: The rate of incidental discovery of colorectal carcinomas during laparoscopic cholecystectomy in our department was 0.24 %. These patients had higher complication rates and a longer hospital stay.

Determination of trace elements (Cu, Zn, Mn, Pb) and magnesium by atomical absorption in patients receiving total parenteral nutrition.

OBJECTIVE: We measured the serum levels of four trace elements (Cu, Zn, Mn, Pb) and Mg in surgical patients receiving total parenteral nutrition (TPN). The clinical implications and the results are discussed. METHODS: Two groups of patients were studied: the first group (n = 40) was our study group and the second (n = 40) was the control group. Four measurements of each trace element (TE) in blood serum were carried out: one before initiating TPN, one 24 h after, one 3 d later, and the last one immediately after discontinuing TPN. Each measurement was repeated twice. The Perkin-Elmer atomic absorption spectrophotometer (model 2380) with furnace graphite HGA-300 was used to measure the TE levels and an acetylene flame was used to measure the Mg levels. RESULTS: Levels of all the TEs, except Pb, were lower before the administration of TPN compared with the control group (P < 0.05). The levels of TEs during and immediately after TPN were generally lower in comparison with the initial measurement before the administration of TPN. CONCLUSION: The results of this study suggest that it may be necessary to 1) add Cu, Zn, Mn, and Mg to the parenteral nutritional solution and 2) follow the fluctuations in serum levels during the administration of TPN.

Implantation of microballoons in the management of fecal incontinence.

PURPOSE: The implantation of expandable microballoons has proved successful for the treatment of stress urinary incontinence. This led us to test its effectiveness in the treatment of severe fecal incontinence. METHODS: Six patients (four male), of average age of 43 (range, 29-60) years, with severe fecal incontinence, underwent implantation of expandable microballoons in the submucosa of the anal canal. The implantation was performed under intravenous sedation as an outpatient procedure. Anal manometry, endosonography, and incontinence assessment with a scoring system were performed before and after the implantation. RESULTS: With a mean follow-up of 8.6 (range, 7-12) months, the incontinence scores improved in all patients from an average of 16.16 (standard deviation: +/- 1.6) before the implantation to an average of 5 (standard deviation: +/- 1.26) after the procedure. The anal pressure at rest was not improved in any patient (mean: 50.16 before treatment to a mean of 53 after treatment). No significant adverse events were associated with the procedure, and no serious postimplantation complications were noted. DISCUSSION: Anal implantation of expandable microballoons seems to be a simple, safe, and effective method that restores the fecal continence without hindering normal defecation.

Prognostic significance of p53, bax and bcl-2 gene expression in patients with laryngeal carcinoma.

AIM: This study was designed to examine the prognostic significance of the coexpression of three genes (bax, bcl-2 and p53) which play a critical role in the apoptotic mechanisms in patients with squamous cell laryngeal carcinoma. MATERIALS AND METHODS: The immunohistochemical expression of bcl-2, bax and p53 genes was retrospectively examined in 38 patients with squamous cell laryngeal carcinoma and in five controls (necrotomic tissue). Tissue specimens were obtained both during the diagnostic biopsy and at the time of surgery. Clinicopathological and survival data were correlated with the staining results. RESULTS: Bcl-2 protein expression (P=0.0472), stage (P=0.0087) and lymph-node involvement (P=0.0488) were found to be independent prognostic factors. Increased bcl-2 protein expression correlated with a better 5-year survival (P=0.0472). Patients who were bcl-2(-)/p53(-) (n=25) or bax(+)/bcl-2(-) (n=13) had a significantly worse overall survival (P=0.0305 and P=0.0482, respectively). Similarly, patients who were bax(+)/bcl-2(-)/p53(-) (n=11) also had a worse 5-year survival compared with the rest of the group (P=0.0088). Changes that were noticed in bax and p53 protein expression from the time of biopsy until the time of surgery did not correlate with a significant increase in the overall survival. CONCLUSIONS: The expression of bcl-2 gene appears to be an independent prognostic factor for patients with laryngeal carcinoma. The coexpression of the genes studied can be used to determine aggressive clinical phenotypes.

Reconstruction of the pancreatic duct after pancreaticoduodenectomy: a modification of the Whipple procedure.

BACKGROUND AND OBJECTIVES: Pancreaticoduodenectomy is still associated with high morbidity and mortality even though there has been significant progress in the field of pancreatic surgery and postoperative follow-up. The pancreatoenteric anastomosis, regardless of the technique used, is a major cause for both morbidity and mortality after Whipple procedure. To overcome all problems resulting from anastomotic leakage, we used external drainage of the pancreatic duct. METHODS: In 24 patients who underwent pancreaticoduodenectomy in our Department from 1986 to 1995, a modification to the standard Whipple procedure was performed. Instead of pancreaticoenteric anastomosis, external drainage of the pancreatic duct remnant was performed. The pancreatic duct was intubated with a silastic tube, the external end of which was sutured to the skin. All patients received substitution therapy with pancreatic enzymes. RESULTS: Mortality in our group of patients was 4%. No complications due to the external drainage of the pancreatic duct were reported, while no patient developed diabetes mellitus after surgery. CONCLUSIONS: External drainage of the pancreatic duct remnant can be used alternatively to pancreatoenteric anastomosis after pancreatoduodenectomy. The technique is safe and simple to perform and appears to reduce overall operative time. It may be an option for patients with significant comorbidity and/or intraoperative hemodynamic instability which mandates expeditious completion of the operation.

Long-term prognostic significance of HSP-70, c-myc and HLA-DR expression in patients with malignant melanoma.

AIM: Use of molecular markers indicative of the tumour oncogenic potential and host response may enhance our prognostic information for more effective treatment of melanoma patients. The roles of HSP-70 protein, c-myc oncogene and HLA-DR antigen expression were examined in melanoma patients and related to prognostic factors, recurrence rate and long-term survival. METHODS: Forty patients with tumours thicker than 1 mm were included in this study. All had elective node dissection and were followed for at least 7 years. Twenty-two had microscopic nodal metastases. Both primary melanoma tumour and lymph nodes were examined for the immunohistochemical expression of HSP-70 protein, c-myc oncogene and HLA-DR antigen. RESULTS: Eighteen patients had a recurrence (45%) and 23 patients survived overall (57.50%). Positive HSP-70 expression was observed in 52.50% of the primary melanomas and was associated with improved overall survival, especially in the patient group with tumours > or = 1.5 mm (70%vs 26.70%, P=0.0159). C-myc oncogene was overexpressed in 47.50% and HLA-DR antigen in 42.50% of the primary melanomas, but no correlation with survival was observed. The expression profile of these molecular markers in the primary tumour did not predict the status of regional nodes. HLA-DR expression in lymph nodes was observed exclusively in the nodal tissue surrounding the metastatic melanoma tumour in five patients. CONCLUSIONS: The immunohistochemical expression profile of HSP-70 but not of c-myc oncogene or HLA-DR antigen in the primary melanoma tumour could be of certain value in the identification of patients with graver prognosis who may benefit from more aggressive therapeutic strategies.

Apoptosis in cells of bronchoalveolar lavage: a cellular reaction in patients who die with sepsis and respiratory failure.

OBJECTIVE: Apoptosis represents a physiologic clearance mechanism in human tissues. The role of apoptosis has not been examined in lung cell populations, such as alveolar macrophages of septic patients, an organ frequently insulted in these patients. This study was designed to examine the effect of sepsis on the apoptosis of alveolar macrophages. DESIGN: Prospective study. SETTING: Intensive care unit and surgical intensive care and trauma unit of a large university hospital in Athens, Greece. PATIENTS: Bronchoalveolar lavage was obtained from 20 consecutive patients who met the criteria for sepsis, admitted to two intensive care units. Bronchoalveolar lavage was obtained from nine volunteers without lung disease who served as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The specimens were analyzed by using annexin V binding, terminal deoxynucleotidyl transfer-mediated deoxyuridine 5-triphosphate nick end labeling (TUNEL), DNA laddering, light microscopy, and immunohistochemistry. Spontaneous apoptosis of bronchoalveolar lavage cells and particularly of alveolar macrophages was significantly decreased in septic patients compared with nonseptic controls. This finding was confirmed by using morphologic criteria and the TUNEL method. Furthermore, gel electrophoresis of DNA obtained from bronchoalveolar cells revealed that DNA fragmentation was not necessarily associated with apoptotic cell death. The bcl-2 gene was minimally expressed in the control group. An inverse correlation was found between the percentage of apoptotic alveolar macrophages and the severity of sepsis. CONCLUSIONS: The prolonged survival of lung cells in septic patients and especially of alveolar macrophages may be attributable to the inhibition of apoptosis. This seems to represent an initial attempt of the host to increase the defense capacity to kill the invading microorganism, resulting in an unbalanced tissue load of cells and an uncontrolled release of toxic metabolites. Furthermore, the inhibition of apoptosis in septic patients may explain why lung function is impaired, leading to sepsis-induced acute respiratory distress syndrome and death.

Laparoscopic or open cholecystectomy in patients with sickle cell disease: which approach is superior?

OBJECTIVE: To compare laparoscopic with open cholecystectomy in patients with sickle cell disease. DESIGN: Retrospective clinical study. SETTING: University hospital, Greece. SUBJECTS: 41 patients (22 men and 19 women) with sickle cell disease had laparoscopic cholecystectomy between September 1991 and June 1998. Each patient was matched for age, sex, year of operation, and number of preoperative transfusions with control patients with sickle cell disease who had open cholecystectomy. MAIN OUTCOME MEASURES: Duration of operation, postoperative stay in hospital, incidence of complications, and conversion to open operation. RESULTS: The mean operation time was 81.4 min (range 55-125) for open cholecystectomy and 64.2 min (range 45-90) for laparoscopic cholecystectomy (p < 0.01). Complications occurred in 5% (2/41) of the patients in the laparoscopic group and in 20% (8/41) of the patients in the open group (p = 0.04). The mean length of stay in hospital was 5.6 days (range 3-9) in the open group and 2.7 days (range 2-5) in the laparoscopic group (p < 0.01). Conversion to open operation was necessary in 2 (5%) patients. CONCLUSIONS: Laparoscopic cholecystectomy resulted in a shorter hospital stay with fewer postoperative complications than open operation in patients with sickle cell disease and may be the procedure of choice in the treatment of cholelithiasis in such patients.

Circulating anti-CEA antibodies in the sera of patients with breast cancer.

AIM: The aim of this study was to detect circulating anti-carcinoembryonic antigen antibodies (anti-CEA) in breast cancer patients and to evaluate their clinical and prognostic significance. METHODS: Fifty-two breast cancer patients and 28 controls were included in this study. Detection of anti-CEA antibodies was performed using a modified enzyme linked immunoassay (ELISA). Sensitivity, specificity and usefulness index of anti-CEA antibodies were compared to those of CEA. The correlation of anti-CEA antibodies with survival and recurrence-free survival was tested with univariate and multivariate analysis. RESULTS: Anti-CEA was present in 57% of breast cancer patients and in 11% of controls. The sensitivity and usefulness index of anti-CEA were significantly better than those of CEA. The specificity of anti-CEA antibodies was less than that of CEA, the difference not being statistically significant. Anti-CEA antibodies were an independent statistically significant, favourable factor in recurrence-free survival. CONCLUSION: Anti-CEA antibodies circulate in breast cancer patients. They could be used as a more sensitive tumour marker than CEA. Their presence is associated with improved recurrence-free survival. These results should be confirmed in a larger series.

Prognostic variables for patients with stage III malignant melanoma.

OBJECTIVE: To evaluate the prognostic factors for patients with stage III malignant melanoma and to identify patients at high risk of developing recurrent disease who may benefit from adjuvant therapy. DESIGN: Retrospective study. SETTING: Specialist hospital, USA. SUBJECTS: 130 patients with stage III malignant melanoma (according to the TNM classification), treated at the Roswell Park Cancer Institute between 1970 and 1992. MAIN OUTCOME MEASURES: Survival and prognostic factors on multivariate analysis. RESULTS: Four factors were independent prognostic indicators for patients with stage III malignant melanoma: age >51 years (p = 0.008), >3 involved lymph nodes, (p = 0.03), the site of the primary tumour on head or trunk, (p = 0.007), and the presence of palpable lymph nodes (p = 0.004). CONCLUSION: These prognostic factors help us to stratify patients into low and high-risk groups. High-risk patients may benefit from more aggressive adjuvant therapy in future trials of treatment of melanoma.

Prognostic significance of circulating antibodies against carcinoembryonic antigen (anti-CEA) in patients with colon cancer.

OBJECTIVE: The discovery of antibodies against carcinoembryonic antigen (CEA) in patients with digestive cancers, in the late 1970s, initiated a number of studies on the role of these antibodies in patients with cancers of the GI tract. Our aim was to determine the prevalence and prognostic significance of the IgG and IgM anti-CEA antibodies in the serum of patients with colon cancer. METHODS: Using an enzyme-linked immunoassay, the sera of 58 colon cancer patients were examined for the presence of carcinoembryonic antigen (CEA) and for circulating antibodies against the CEA (anti-CEA). An inhibition assay was carried out for the determination of the specificity of the IgG and IgM anti-CEA antibodies. RESULTS: The CEA was elevated (> or =10 ng/ml) in only 12 patients (20.6%). Anti-CEA IgM and/or IgG antibodies were detected in 46 patients with colon cancer (79.1%). In the control group (n = 28), 10% of the individuals had detectable amounts of IgG and/or IgM anti-CEA antibodies. Patients with detectable amounts of circulating IgM anti-CEA antibodies (n = 14, 30.5%) had a statistically significantly better 2-yr survival compared to the rest of the patients (p = 0.017). The IgM anti-CEA antibodies can also be used as an independent prognostic factor in these patients (p = 0.0323). CONCLUSIONS: In this study, a high number of colon cancer patients have circulating anti-CEA antibodies in their sera. These may be used as diagnostic markers and as independent prognostic factors. In addition, the presence of these antibodies in the patients studied is associated with better prognosis and significantly increased 2-yr survival. It was also found that the anti-CEA antibodies (IgG and IgM) are more sensitive markers than CEA. These findings underline the biological importance of the anti-CEA antibodies and provide additional information on their potential use as markers of the immune status in patients with colon cancer.

Protein expression of bax, bcl-2, and p53 in patients with non-Hodgkin's gastric lymphoma: prognostic significance.

The biologic significance of bcl-2, bax, and p53 gene expression in patients with non-Hodgkin's gastric lymphoma is unknown. We examined the prognostic value of these genes in 36 patients with gastric lymphoma treated in our clinic between 1990 and 1995. Paraffin-embedded specimens from 36 patients who underwent primary resection of the stomach for gastric lymphoma were analyzed immunohistochemically for p53, bax, and bcl-2 gene expression. Expression of bax was seen in 24 of 36 patients (66.7%), p53 expression was found in 8 of 36 tumors (22.2%), and bcl-2 cytoplasmic staining was detected in 6 of 36 patients (16.7%). We performed a univariate analysis to examine the possible correlation between the expression of these genes and the survival of our patients. Expression of bax protein proved to be a statistically significant prognostic factor (p = 0.049). Protein expression of p53 and bcl-2 did not statistically correlate with survival. In the bcl-2-negative (-) patient group (30 patients), those who were bax-positive had a statistically significant better survival than those who were bax-negative (63.3% vs. 36.7%, p = 0.03). There was also a statistically significant correlation between p53 expression and the grade of the tumor (p = 0.0014). P53 protein expression increased along with the grade. Expression of bax is a significant prognostic factor in patients with gastric lymphoma. Its prognostic value increases significantly when studied in bcl-2-negative patients; but expression of bax failed to be an independent prognostic factor. Expression of bcl-2 and p53 has no prognostic significance. Expression of p53 seems to represent a marker for loss of differentiation.