Clinical relevance of KRAS mutation detection in metastatic colorectal cancer treated by Cetuximab plus chemotherapy

The predictive value of KRAS mutation in metastatic colorectal cancer (MCRC) patients treated with cetuximab plus chemotherapy has recently been suggested. In our study, 59 patients with a chemotherapy-refractory MCRC treated with cetuximab plus chemotherapy were included and clinical response was evaluated according to response evaluation criteria in solid tumours (RECIST). Tumours were screened for KRAS mutations using first direct sequencing, then two sensitive methods based on SNaPshot and PCR-ligase chain reaction (LCR) assays. Clinical response was evaluated according to gene mutations using the Fisher exact test. Times to progression (TTP) were calculated using the Kaplan–Meier method and compared with log-rank test. A KRAS mutation was detected in 22 out of 59 tumours and, in six cases, was missed by sequencing analysis but detected using the SNaPshot and PCR-LCR assays. Remarkably, no KRAS mutation was found in the 12 patients with clinical response. KRAS mutation was associated with disease progression (P=0.0005) and TTP was significantly decreased in mutated KRAS patients (3 vs 5.5 months, P=0.015). Our study confirms that KRAS mutation is highly predictive of a non-response to cetuximab plus chemotherapy in MCRC and highlights the need to use sensitive molecular methods, such as SNaPshot or PCR-LCR assays, to ensure an efficient mutation detection.

Treatment of poorly differentiated neuroendocrine tumours with etoposide and cisplatin

The purpose of this study was to evaluate by a retrospective analysis of 53 patients the efficacy of chemotherapy combining etoposide and cisplatin in the treatment of neuroendocrine tumours. The regimen was a combination of etoposide 100 mg m(-2) day(-1) for 3 days and cisplatin 100 mg m(-2) on day 1, given by 2-h intravenous infusion, administered every 21 days. Twelve patients had a well-differentiated and 41 a poorly differentiated neuroendocrine tumour. Toxicity of treatment was assessed in 50 patients and efficacy in 52 patients. Among the 11 patients with a well-differentiated tumour evaluable for tumoural response, only one (9.4%) had a partial response for 8.5 months. Forty-one patients with a poorly differentiated tumour showed an objective response rate of 41.5% (four complete and 13 partial responses); the median duration of response was 9.2 months, the median overall survival 15 months and the median progression-free survival 8.9 months. Haematological grade 3-4 toxicity was observed in 60% of the cases with one treatment-related death, digestive grade 3-4 toxicity in 40% and grade 3 alopecia was constant. No severe renal, hearing and neurological toxicities were observed (grade 1 in 6%, 14%, 72% respectively and no grade >1). We confirm that poorly differentiated neuroendocrine tumours are chemosensitive to the etoposide plus cisplatin combination. However, the prognosis remains poor with a 2-year survival lower than 20% confirming that new therapeutic strategies have to be developed.

Neuron-specific enolase and chromogranin A as markers of neuroendocrine tumours

Circulating neuron-specific enolase (NSE) and chromogranin A (CgA) were measured in 128 patients with neuroendocrine tumours (NET) to compare their sensitivity and specificity, to investigate factors associated with elevated serum levels and to determine the usefulness of these markers in the follow-up of NET patients. NSE (Cispack NSE, Cis Bio International, Gif-sur-Yvette, France; normal <12.5 microg l(-1)), and chromogranin A (CgA-Riact, Cis Bio International, normal <100 microg l(-1)) were measured in 128 patients without renal insufficiency. There were 99 patients with gastroenteropancreatic (GEP) NET, 19 with medullary thyroid carcinoma and ten with phaeochromocytoma. Fifty-three patients with non-NET were studied as controls. Serum NSE and CgA levels were elevated in 48 (38%) and 76 (59%) of the 128 NET patients respectively. In all groups of NET patients, CgA proved to be more sensitive than NSE. NSE and CgA had a specificity of 73% and 68% respectively. Immunostaining for NSE was positive in three out of eight controls with elevated CgA levels, whereas immunostaining for CgA and synaptophysin was negative in all cases. Elevated CgA levels were significantly associated with two independent parameters, namely the presence of other secretions (P = 0.0001) and a heavy tumour burden (P = 0.001). Elevated NSE levels were exclusively associated with poor tumour differentiation (P = 0.01). Among six patients with NET followed for 11-37 months, CgA appeared to be a better marker of tumour evolution than NSE. We suggest that CgA ought to be the only general marker screened in NET patients.

Antitumour activity of somatostatin analogues in progressive metastatic neuroendocrine tumours

A few studies have suggested an antitumour activity of somatostatin analogues in neuroendocrine tumours (NET). The aim of this study was to evaluate the antitumour efficacy of somatostatin analogues in patients with documented progressive tumours. 35 consecutive patients with documented tumour progression were treated with somatostatin analogues. Patients were classified into two groups. In Group 1, tumours were progressing rapidly (an increase of 50% or more in the lesion surface area in 3 months) and in Group 2, tumours were progressing more slowly (an increase of less than 50% in the lesion surface area in 3 months but greater than 25% in 6 months). Treatment consisted of subcutaneous (s.c.) octreotide, 100 microg thrice daily for 17 patients, intramuscular lanreotide, 30 mg/every 14 days for 11 patients and for 7 patients both somatostatin analogues were used successively during the follow-up. Primary tumour sites were the small intestine (n=12), pancreas (n=13), lungs (n=5), and other sites (n=5). 18 patients had the carcinoid syndrome with flushing and/or diarrhoea. The median duration of treatment was 7 months. Treatment was discontinued in 3 patients due to side-effects. One patient (3%) achieved a partial response and the disease was stabilised in 20 patients (57%) for a median duration of 11 months (6-48 months). Stabilisation of patients in Group 1 was significantly less frequent at 6 months than that of patients in Group 2 (4/12 and 13/17 respectively, P<0.02). Somatostatin analogue treatment resulted in one partial response (3%) and 20 cases of stabilisation (57%) in 35 patients with progressive NET. A slow tumour growth rate before treatment is predictive of a good response to somatostatin analogues which could be considered an option for first-line treatment.

Expression of chemokine receptors predicts the site of metastatic relapse in patients with axillary node positive primary breast cancer

BACKGROUND

Recent studies have suggested that chemokine receptors are involved in development of organ-specific pattern of metastases. In the present study, we evaluated the association between the chemokine receptors expressed in primary tumor cells and the site of metastatic relapse in patients with breast cancer.

METHODS

Primary tumors were obtained from 142 patients with axillary node-positive breast cancer and stained for CX3CR1, CXCR4, CCR6, and CCR7 expression. All statistical analyses were adjusted for systemic post-operative treatment.

RESULTS

After a median follow-up of 13 years, none of the chemokine receptors was associated with overall survival or disease free survival. However, expression of chemokine receptors was found to be associated with increased risk of relapse in certain organs. By estimating the Mantel-Haenszel odds ratios (OR), CXCR4 was associated with increased risk of metastasis to the liver (OR = 3.71, P = 0.005), CX3CR1 was associated with metastasis to the brain (OR = 13.18, P = 0.01). Patients with CCR6 positivity were more likely to develop a first metastasis in the pleura (OR = 2.82, P = 0.06). In addition, CCR7 expression was associated with the occurrence of skin metastases (11% versus 0%, P = 0.017).

INTERPRETATION

Expression of chemokine receptors in the primary tumor predicts the site of metastatic relapse in patients with axillary node positive breast cancer. This study, in concordance with the data obtained in animal models, suggests that the chemokine receptors family could be the biological support of the 'seed and soil' theory.

Anti-Müllerian hormone is a specific marker of sertoli- and granulosa-cell origin in gonadal tumors

Sex cord stromal tumors are gonadal neoplasms containing Sertoli, granulosa, Leydig, or thecal cells, which originate from cells derived from either the sex cords (Sertoli and granulosa cell tumors) or the specific mesenchymal stroma (Leydig and thecal cell tumors) of the embryonic gonad. Only granulosa and Sertoli cells produce anti-Müllerian hormone (AMH). Our purpose was to investigate whether AMH can be used as a specific marker of human granulosa or Sertoli cell origin in gonadal tumors, to distinguish them from other primary or metastatic neoplasms, using immunohistochemistry. We studied 7 juvenile and 6 adult-type granulosa cell tumors of ovarian localization and 3 extraovarian metastases, 20 other ovarian tumors, 6 testicular Sertoli cell tumors, 2 gonadoblastomas, and 13 extragonadal tumors. Granulosa cell tumors, both juvenile- and adult-type of either ovarian or metastatic localization, showed an heterogeneous pattern of AMH immunoreactivity: Areas containing intensely or weakly AMH-positive cells were intermingled with AMH-negative areas. Although in most cases AMH-positive areas represented a minor proportion of tumor cells, we found a positive reaction in all the cases examined. In testes, although normal prepubertal Sertoli cells were intensely positive, testicular Sertoli cell tumors showed large areas of negative reaction, with few positive cells scattered throughout the tumor. AMH was also reactive in most of the cells of sex-cord origin in gonadoblastomas. No AMH immunoreaction was observed in other gonadal and extragonadal tumors. We conclude that AMH expression is conserved in only a small proportion of tumor cells of granulosa or Sertoli cell origin; however, a positive reaction in a few cells helps to distinguish between granulosa or Sertoli cell tumors or gonadoblastomas and other gonadal tumors of different origin.

Immunohistochemical expression of WT1 by desmoplastic small round cell tumor: a comparative study with other small round cell tumors

Desmoplastic small round cell tumors (DSRCTs) present a reciprocal chromosomal translocation, t(11;22)(p13;q12), that results in fusion of Ewing's sarcoma and Wilms' tumor (WT1) genes. The authors evaluated 15 DSRCTs and 71 other tumors often considered in the differential diagnosis for immunoreactivity using a polyclonal antibody directed against the WT1 part of the chimeric protein resulting from this translocation. WT1 immunostaining was performed on paraffin material using the WT(C-19) antibody after heat-antigen retrieval. All the DSRCTs (15 of 15, 100%) demonstrated strong WT1 nuclear immunoreactivity. Ten of 14 nephroblastomas (71%) disclosed WT1-positive nuclei in accordance with the staining reported by others, and rare and focal nuclear positivity was detected in two of 17 rhabdomyosarcomas. WT1 immunoreactivity was not observed in Ewing's sarcoma/primitive neuroectodermal tumors (zero of 21, 0%), neuroblastomas (zero of 17, 0%), or rhabdoid tumors of the kidney (zero of two, 0%). In nephroblastoma, differential diagnosis with DSRCT was not difficult: Clinical and morphologic data are not similar for these two entities. The current study validates WT1 immunoreactivity as a useful marker to separate DSRCT from other small round cell tumors.

Results of 136 curative hepatectomies with a safety margin of less than 10 mm for colorectal metastases

BACKGROUND AND OBJECTIVES

It is now established that liver resection is beneficial for metastases from colorectal cancer. Nevertheless, a surgical margin estimated at less than 10 mm at preoperative imaging is considered an absolute contraindication to surgery by some, and a relative contraindication by others. The true impact of the width of the margin on the prognosis is unclear.

METHODS

From 1984 to 1996, 196 patients underwent curative hepatectomy for liver metastases and were studied prospectively. Surgery was to be curative (or a complete R0 resection) and mortality was to be avoided. Of these 196 patients, 136 had surgical margins of less than 10 mm. Sixty-eight percent had multiple liver metastases and 15% had extrahepatic metastatic lesions. Clinical and pathological factors were studied specifically and a multivariate analysis was carried out.

RESULTS

Overall 5-year survival rate of these 136 patients (taking into account postoperative mortality which attained 1.5%) was 27.8% and the disease-free survival was 22.9%. The surgical margin was 0 mm in 30 cases. The sole prognostic factor was the discovery of unsuspected (resectable) extrahepatic lesions at laparotomy (P < 0.001) ; the width of the free margin had no significant effect. However, in the multivariate analysis of prognostic factors for the entire series (269 hepatectomies), three powerful parameters were identified : (1) the curative nature of resection (P = 0.0007), (2) less than 20% of liver involvement (P = 0.002), and (3) a free margin exceeding 9 mm (P = 0.02). A correlation was found between narrow margins and extensive disease (high number of metastases, bilateral sites, and extended hepatectomy). There was also a greater likelihood of microscopic satellite lesions within 10 mm around the metastases.

CONCLUSIONS

The prognostic impact of the width of the surgical margin should not be overestimated. Hepatectomy for liver metastases can procure long-term survival, even in patients with supposedly poor prognostic factors. Resection is justified as long as it is complete and the risks are minimal.

Prognostic factors after surgery of primary resectable gastrointestinal stromal tumours

AIMS

To analyse the prognostic factors of gastrointestinal stromal tumours (GIST) after a complete resection of the primary tumour.

PATIENTS AND METHODS

Fifty-nine patients who underwent a complete initial resection of a GIST were studied. Peritumoral resections (PTR) were compared to segmental organ resections (SOR). Overall survival (OS) and the disease-free survival (DFS) were calculated using the Kaplan-Meier method.

RESULTS

Primary sites were: stomach (25), small intestine (22), rectum (7), duodenum (5). Two patients had nodal involvement. The median follow-up was 45 months. Local DFS was significantly better after SOR compared to PTR (median 63 vs. 11 months, respectively, p<0.001). Univariate analysis for OS identified the grade (p=0.005) and size (p=0.02) as prognostic factors. Only a high histologic grade was an independent factor (p=0.02) in the multivariate analysis. Out of 49 patients who relapsed, the first recurrence was local only in 12, local and distant in 10 and distant only in 27; only one had a lymph node failure. Recurrences were accessible to curative surgery in 22 cases. OS of patients submitted to complete resection of their recurrence was significantly better than patients whose recurrence could not be resected (median 52 vs. 12 months, respectively, p<0.001).

CONCLUSION

Complete surgery without rupture remains the mainstay of treatment in patients with localized, resectable disease. A peri-tumoral resection confers a high risk of local recurrence and should be avoided. Lymphadenectomy is not systematic. Grade is the main prognostic factor for OS and can be a decision marker for adjuvant treatment with Gleevec.

Frequent alteration of DNA damage signalling and repair pathways in human colorectal cancers with microsatellite instability

Accumulation of frameshift mutations at genes containing coding mononucleotide repeats is thought to be the major molecular mechanism by which mismatch repair-deficient cells accumulate functional alterations. These mutations resulting from microsatellite instability (MSI) can affect genes involved in pathways with a putative oncogenic role, but may also arise in genes without any expected role in MSI carcinogenesis because of the high mutation background of these tumours. We here screened 39 MSI colorectal tumours for the presence of mutations in 25 genes involved in DNA damage signalling and repair pathways. Using a maximum likelihood statistical method, these genes were divided into two different groups that differed significantly in their mutation frequencies, and likely represent mutations that do or do not provide selective pressure during MSI tumour progression. Interestingly, the so-called real-target mutational events were found to be distributed among genes involved in different functional pathways of the DNA metabolism, for example, DNA damage signalling (DNA-PKcs, ATR), double-strand break (DSB) repair (DNA-PKcs, RAD50), mismatch repair (MSH3, MSH6, MBD4) and replication (POLD3). In particular, mutations in MRE11 and/or RAD50 were observed in the vast majority of the tumours and resulted in the concomitant loss of immunohistochemical expression of both proteins. These data might explain why MSI colorectal cancers (CRC) behave differently in response to a wide variety of chemotherapeutic agents, notably those targeting DNA. More generally, they give further insights into how MSI leads to functional changes with synergistic effects in oncogenic pathways.

bcl-2 expression in normal breast tissue during the menstrual cycle

bcl-2 is a proto-oncogene discovered through the t(14;18) translocation occurring in most human follicular lymphomas. The function so far attributed to bcl-2 is to counteract the occurrence of apoptosis and to prolong cell survival without affecting the cycling cells. Apoptosis has been described in normal breast tissue epithelial cells, and it peaks at the end of the luteal phase. We have studied bcl-2 expression by an immunohistochemical method in 50 samples of normal breast tissue distributed throughout the menstrual cycle. bcl-2 staining predominated in the lobular epithelial cells. It displayed a striking cyclic variation, with maximal expression at the mid-cycle period and a sharp decrease at the end of the cycle. These results strongly suggest that the regulation of bcl-2 expression in breast tissue is hormone-dependent. This could be of significance in tumorigenesis.

Resection of liver metastases from colorectal cancer: the real impact of the surgical margin

AIMS

The benefit of liver resection for metastatic colorectal cancer is now established. Nevertheless if the surgical margin on pre-operative imaging is considered to be less than 10 mm, this is considered an absolute contraindication to surgery by some, and a relative contraindication by others, so its real impact on prognosis is not clear.

METHODS

From 1984 to 1996, 269 patients underwent hepatectomy for liver metastases and were prospectively studied. The only two objectives of this surgery were to be curative (or achieve complete R0 resection), and to avoid mortality. Of the 269, 187 patients had surgical margins inferior to 10 mm. Sixty per cent had multiple liver metastases, and 37% had extrahepatic metastatic sites. Their clinical and pathological factors were specifically studied.

RESULTS

The crude 5-year survival of these 187 patients (including the 2% post-operative mortality) was 24.7%, and the disease-free survival was 18.8%. The surgical margin was 0 mm in 60 cases and was histologically invaded in 20 cases. The most important prognostic factor was whether the resection was considered palliative (R1-R2 resection according to UICC criteria) (P < 0.0001). When the cases with invaded margins were excluded, there was not prognostic difference between the 107 patients with a margin of 0-4 mm and the 143 patients with a margin greater than 4 mm. However, a surgical margin greater than 9 mm appears to be a second prognostic factor (P = 0.001), when these 187 patients are compared to others. The reasons behind this are that there is a close relationship between narrow margins and extensive disease (high number of metastases, bilateral localization and extended hepatectomy), and also an increased possibility of microscopic satellite lesions within 10 mm around the metastases.

CONCLUSION

The real prognostic impact of the surgical margin must not be overestimated. Hepatectomy for metastases can provide long-term survival in patients with supposed poor prognostic factors. Resection is justified so long as it is complete and with minimal risk. An experienced, specialized centre can be a prognostic determinant.

The doxorubicin-streptozotocin combination for the treatment of advanced well-differentiated pancreatic endocrine carcinoma; a judicious option?

Due to their rarity, only few trials have studied the role of the doxorubicin-streptozotocin (DS) combination in advanced well-differentiated pancreatic endocrine carcinomas (AWDPEC). However, the published results are inconsistent. We reviewed all AWDPEC (5-year period, 45 patients) treated in our institution with the DS combination for: objective response rate (ORR), progression-free survival, overall survival (OS) and toxicity. An ORR of 36% (95% Confidence Interval (CI) 22-49) was obtained, with 16 partial responses (PR). The mean duration of PR was of 19.7 months. Two and 3-year OS rates were 50.2 and 24.4%, respectively. Toxicities were mainly digestive (grade > or =3 vomiting, 13%) and haematological (grade > or =3 neutropenia, 24%). Previous systemic chemotherapy and malignant hepatomegaly were associated with a poorer ORR (P=0.033, P=0.016) and OS (P=0.008, P=0.045). Multivariate analysis demonstrated previous chemotherapy as the only independent predictive-factor for survival (P=0.013). In conclusion, our data confirm the sensitivity of AWDPEC to the DS combination, with an ORR of 36% and a remarkable median response duration of 19.7 months, and suggests that it could be considered as a valid option in first-line therapy.

Frequencies of KIT and PDGFRA mutations in the MolecGIST prospective population-based study differ from those of advanced GISTs

Gastrointestinal stromal tumors (GISTs) are the most common human sarcoma. Most of the data available on GISTs derive from retrospective studies of patients referred to oncology centers. The MolecGIST study sought to determine and correlate clinicopathological and molecular characteristics of GISTs. Tumor samples and clinical records were prospectively obtained and reviewed for patients diagnosed in France during a 24-month period. Five hundred and ninety-six patients were included, of whom 10% had synchronous metastases. GISTs originated from the stomach, small bowel or other site in 56.4, 30.2 and 13.4% of cases, respectively. The main prognostic markers, tumor localization, size and mitotic index were not independent variables (P < 0.0001). Mutational status was determined in 492 (83%) patients, and 138 different mutations were identified. KIT and PDGFRA mutations were detected in 348 (71%) and 74 (15%) patients, respectively, contrasting with 82.8 and 2.1% in patients with advanced GIST (MetaGIST) (P < 0.0001). Further comparison of localized GISTs in the MolecGIST cohort with advanced GISTs from previous clinical trials showed that the mutations of PDGFRA exon18 (D842V and others) as well as KIT exon11 substitutions (W557R and V559D) were more likely to be seen in patients with localized GISTs (odds ratio 7.9, 3.1, 2.7 and 2.5, respectively), while KIT exon 9 502_503dup and KIT exon 11 557_559del were more frequent in metastatic GISTs (odds ratio of 0.3 and 0.5, respectively). These data suggest that KIT and PDGFRA mutations and standardized mitotic count deserve to be investigated to evaluate the relapse risk of GISTs.

The reliability of immunohistochemistry as a prescreening method for the diagnosis of hereditary nonpolyposis colorectal cancer (HNPCC)--results of an international collaborative study

Hereditary nonpolyposis colorectal cancer syndrome (HNPCC) is an autosomal dominant condition accounting for 2-5% of all colorectal carcinomas as well as a small subset of endometrial, upper urinary tract and other gastrointestinal cancers. An assay to detect the underlying defect in HNPCC, inactivation of a DNA mismatch repair enzyme, would be useful in identifying HNPCC probands. Monoclonal antibodies against hMLH1 and hMSH2, two DNA mismatch repair proteins which account for most HNPCC cancers, are commercially available. This study sought to investigate the potential utility of these antibodies in determining the expression status of these proteins in paraffin-embedded formalin-fixed tissue and to identify key technical protocol components associated with successful staining. A set of 20 colorectal carcinoma cases of known hMLH1 and hMSH2 mutation and expression status underwent immunoperoxidase staining at multiple institutions, each of which used their own technical protocol. Staining for hMSH2 was successful in most laboratories while staining for hMLH1 proved problematic in multiple labs. However, a significant minority of laboratories demonstrated excellent results including high discriminatory power with both monoclonal antibodies. These laboratories appropriately identified hMLH1 or hMSH2 inactivation with high sensitivity and specificity. The key protocol point associated with successful staining was an antigen retrieval step involving heat treatment and either EDTA or citrate buffer. This study demonstrates the potential utility of immunohistochemistry in detecting HNPCC probands and identifies key technical components for successful staining.

TP53 mutations predict disease control in metastatic colorectal cancer treated with cetuximab-based chemotherapy

Recent studies have suggested that activation of the EGFR pathway leads to malignant transformation only if the p53 protein is inactivated. Therefore, we evaluated the impact of TP53 mutations on cetuximab-based chemotherapy (CT) sensitivity in combination with KRAS mutations that have been associated with cetuximab resistance. KRAS and TP53 status were assessed in tumours from 64 metastatic colorectal cancer patients treated with cetuximab-based CT and correlated to clinical response using the Fisher's exact test. Times to progression (TTPs) according to gene status were calculated using the Kaplan-Meier method and compared with log-rank test. TP53 mutations were found in 41 patients and were significantly associated with controlled disease (CD), as defined as complete response, partial response or stable disease (P=0.037) and higher TTP (20 vs 12 weeks, P=0.004). Remarkably, in the subgroup of 46 patients without KRAS mutation, but not in patients with KRAS mutation, TP53 mutations were also associated with CD (P=0.008) and higher TTP (24 vs 12 weeks, P=0.0007). This study suggests that TP53 mutations are predictive of cetuximab sensitivity, particularly in patients without KRAS mutation, and that TP53 genotyping could have a clinical interest to select patients who should benefit from cetuximab-based CT.

Molecular determinants of anti-EGFR sensitivity and resistance in metastatic colorectal cancer

Since 2004, the clinical impact of monoclonal antibodies (mAbs) targeting the epidermal growth factor receptor (EGFR) on patients with metastatic colorectal cancer (MCRC) has been clearly established. The combination of these biological agents with conventional chemotherapy has led to a significant improvement in response rate, progression-free survival and overall survival in first-line as well as in second- or third-line treatment of MCRC. However, the high variability of response and outcome in MCRC patients treated with these anti-EGFR mAbs has highlighted the need of identifying clinical and/or molecular predictive markers to ensure appropriate use of targeted therapies. The presence of somatic KRAS mutations has been clearly identified as a predictive marker of resistance to anti-EGFR in MCRC, and the use of anti-EGFR mAbs is now restricted to patients with no detectable KRAS mutation. Several studies have indicated that amplification of EGFR, overexpression of the EGFR ligands and inactivation of the anti-oncogene TP53 are associated with sensitivity to anti-EGFR mAbs, whereas mutations of BRAF and PIK3CA and loss of PTEN expression are associated with resistance. Besides these somatic variations, germline polymorphisms such as those affecting genes involved in the EGFR pathway or within the immunoglobulin receptors may also modulate response to anti-EGFR mAbs. Until now, all these markers are not completely validated and only KRAS genotyping is mandatory in routine practice for use of the anti-EGFR mAbs in MCRC.

Immunohistochemical analysis of Na+/I- symporter distribution in human extra-thyroidal tissues

131Iodine concentration has been described in several extra-thyroidal tissues. Recent evidence has shown that iodine uptake is achieved by the recently cloned human Na(+)/I(-) symporter (hNIS) gene. However, conflicting results were observed in the expression of hNIS transcripts in extra-thyroidal tissues. In order to document further the distribution of hNIS, we investigated its expression using an immunohistochemical method, based on a polyclonal antibody raised against a synthetic peptide. Various extra-thyroidal tissues were examined, particularly from the digestive tract. Our results confirm that the salivary glands and the stomach express hNIS protein significantly. In contrast, hNIS was undetectable in the colon but the rectal mucosa, which has never been examined, exhibited positive immunohistochemical staining. Other digestive tissues, including the oesophagus, small intestine and appendix, were negative. Weak staining was observed in the mammary gland, indicating that hNIS is expressed in this tissue. The pancreas, skin, ovaries, spleen and kidney showed no positive immunostaining.

Inhibin B is the major form of inhibin/activin family secreted by granulosa cell tumors

Both experimental and clinical studies suggest that inhibin plays a critical role in the development of granulosa cell tumors (GCT), a subgroup of malignant ovarian tumors. Inhibin has been proposed as a biological marker for the follow-up of patients bearing these particular tumors. Hitherto, there is no general agreement on the molecular form(s) of the inhibin family that are secreted by malignant granulosa cells. Using specific and sensitive immunoassays for activin A and for inhibins A and B, we investigated the production of these molecules in patients with either an adult GCT (n=13) or an epithelial ovarian cancer (n=11). Results showed that serum activin A level was increased in all patients, independently of their clinical status (progressive disease or remission) in comparison to that observed in the healthy pre- and postmenopausal women. Most of the patients also presented a moderate increase in serum inhibin A level compared to that in controls. Only one of eight patients with a progressive granulosa cell tumor had a high value of serum inhibin A. In contrast, serum inhibin B was dramatically increased in eight of nine patients with a granulosa cell tumor and its level correlated with the clinical status of the patients. No correlation was found between the level of serum inhibin B and that of serum antimüllerian hormone, a recently described specific and reliable marker for GCT. None of the patients with an epithelial ovarian cancer presented an increase of serum inhibin B. These observations demonstrate that inhibin B is the major molecular form of the inhibin family proteins produced by malignant granulosa cells.

Radio-frequency tissue ablation of the liver: effects of vascular occlusion on lesion diameter and biliary and portal damages in a pig model

The aim of this study was to assess the effect of vascular occlusion on radio-frequency (RF) lesion size and on potential associated biliary and portal lesions. Radio-frequency lesions using a 1-cm exposed-tip cooled electrode were created in pig liver. Liver perfusion was modified by arterial embolization (n=2), left portal clamping (n=2), and both (n=2). Two pigs were used as controls. Two weeks after, control portography was performed, animals were killed, and ex-vivo cholangiography was carried out. Pathological studies evaluated the lesion surface and associated portal and biliary damages. A mathematical regression model showed that portal occlusion increased by 43 mm2 (+40%) the surface of RF lesions, arterial occlusion by 135 mm2 (+126%), and associated occlusion by 466 mm2 (+435%). Biliary stenoses were found in 4 cases (two arterial occlusions, one portal occlusion, and one associated occlusion). One case of partial portal vein thrombosis was found in one case of portal occlusion and resolved at 2 weeks. Ischemic damages adjacent to RF lesions were found in cases of combined occlusions. The reduction of liver perfusion increases significantly the size of RF lesions but is associated with a risk of biliary, portal, or parenchymal complications.

[Treatment of peritoneal carcinomatosis using complete excision and intraperitoneal chemohyperthermia. A phase I-II study defining the best technical procedures]

OBJECTIVES

The complete or quasi complete resection of peritoneal carcinomatosis (PC) followed with IPCH is potentially able to cure some patients with a disease confined to the peritoneum. The aim of this prospective phase I-II study was to elaborate an efficient IPCH procedure with a good thermal homogeneity and a good spatial diffusion, which should be reproductible (and so standardizable and exportable), and to appreciate its tolerance and its carcinologic impact.

PATIENTS AND METHODS

Seven IPCH procedures were successively tested in 32 patients (for a total of 35 IPCH); each of these were tested in at least four patients before being modified for technical or tolerance reason. Five of them were followed with an immediate postoperative intraperitoneal chemotherapy (IPIC) lasting four days. Thermal homogeneity was measured with six thermal probes situated in different places inside the abdominal cavity. Spatial diffusion was studied in the last patients by adding methylene blue in the IPCH liquid. The precise extent of the PC was reported, for each intra-abdominal region, and scored with a peritoneal index (ranging from 1 to 39). The mean follow-up was 23.85 months for the series.

RESULTS

Procedures with the closure of the abdomen were not efficient: thermal homogeneity was almost satisfactory when only the skin was closed, but these 'closed' procedures did not permit the treatment of all the risky surfaces. The peritoneal cavity 'expander' did not permit the treatment of the parietal wound, and an undetermined amount of the perfusion oozed out at its periphery. The open technique by tracking the skin upwards was the best one. Death occurred in three patients (9.4%), and complications occurred in 24 patients (75%) during the postoperative course. Intra-abdominal complications were significantly correlated (P = 0.02) with the peritoneal index (scoring the extent of the PC). The two year survival rate was 60%, and PC did not recur in 50% of the patients.

CONCLUSION

An efficient and reproducible procedure for IPCH was defined: an open procedure with an upwards traction of the skin. The post-IPCH IPIC was abandoned because it did not treat all the risky peritoneal surfaces. Patients with an extended PC and with extraperitoneal localization did not seem to have benefited from this therapeutic approach. Progress is needed in the chemotherapeutical procedure and indications must be more finely defined.

Efficacy of adjuvant chemotherapy according to Prion protein expression in patients with estrogen receptor-negative breast cancer

BACKGROUND

Prion protein (PrPc) has been previously reported to be associated with resistance to proapoptotic stimuli. We evaluated whether the expression of PrPc was associated with the resistance to adjuvant chemotherapy in patients with estrogen receptor (ER) -negative breast cancer.

PATIENTS AND METHODS

The expression of PrPc by primary tumors was assessed by immunohistochemistry in a series of 756 patients included in two randomized trials that compared anthracycline-based chemotherapy to no chemotherapy. The PrPc expression was correlated with ER expression and the benefit of adjuvant chemotherapy was assessed according to PrPc expression in patients with ER-negative tumors.

RESULTS

Immunostaining analysis showed that PrPc was mainly expressed by myoepithelial cells in normal breast tissue. Tissue microarray analysis from 756 breast tumors showed that PrPc was associated with ER-negative breast cancer subsets (P < 0.001). Adjuvant chemotherapy was not associated with a significant risk reduction for death in patients with ER-negative/PrPc-positive disease [adjusted hazard ratio (HR) for death = 0.98, 95% confidence interval (CI) 0.45-2.1, P = 0.95], while it decreased the risk for death (HR = 0.39, 95% CI 0.2-0.74, P = 0.004) in patients with ER-negative/PrPc-negative tumors.

CONCLUSION

These data indicate that ER-negative/PrPc-negative phenotype is associated with a high sensitivity to adjuvant chemotherapy.

Epstein-Barr virus (EBV) genomes and EBV-encoded latent membrane protein (LMP) in pulmonary lymphomas occurring in nonimmunocompromised patients

Recently, in situ hybridization (ISH) techniques have shown that Epstein-Barr virus (EBV) could be detected in tumor cells of most angiocentric T-cell non-Hodgkin's lymphomas (NHL). These studies included only a few cases of T-NHL of the lung and pulmonary B-NHL and have not been investigated. Furthermore, the expression of the EBV-encoded latent membrane protein (LMP), which is known for its oncogenic properties, has not been reported. Twelve pulmonary NHL (six angiocentric T-NHL and six B-NHL) arising in nonimmunocompromised patients were examined for the presence of EBV-EBER mRNAs and LMP with ISH and immunohistochemistry, respectively. Four cases of pulmonary lymphomas arising in immunocompromised patients were also included in the study for comparison (one T-NHL in a patient under immunosuppressive treatment and three B-NHL in AIDS patients). EBV-RNA and LMP were detected in tumor cells in two of six nonimmunocompromised angiocentric T-NHL and in the four immunocompromised NHL. The six nonimmunocompromised B-NHL were EBV negative. These results suggest that EBV is associated with some angiocentric pulmonary T-NHL arising in patients without overt immunodeficiency whereas it is absent in such patients with B-NHL. The presence of the transforming EBV-encoded LMP in tumor cells suggests that EBV may be involved in the pathogenesis of some pulmonary T-NHL.

Prognostic value of maspin mRNA expression in ER alpha-positive postmenopausal breast carcinomas

Maspin, a member of the serpin family, has a role in cell migration, angiogenesis and apoptosis. Little is known of the clinical significance of maspin gene expression in human cancers. We developed a real-time quantitative RT-PCR assay to quantify the full range of maspin mRNA copy numbers in a series of 10 ER alpha-positive and 10 ER alpha-negative breast tumours. We observed a statistical link between low maspin mRNA levels and positive oestrogen status (P=0.0012). In consequence, to better assess the prognostic value of maspin gene expression in breast cancer, we then quantified maspin mRNA content in an additional independent well-defined cohort of 105 ER alpha-positive postmenopausal breast cancer patients treated with primary surgery followed by adjuvant tamoxifen alone. Maspin expression varied widely in tumour tissues (by nearly four orders of magnitude), being underexpressed in 33 out of 105 tumours (31.4%) and overexpressed in 24 out of 105 tumours (22.9%) relative to normal breast tissues. Immunohistochemical studies demonstrated that maspin protein was strictly expressed in myoepithelial cells of normal breast tissue and in tumour epithelial cells, exclusively in maspin-overexpressing tumours. Patients with tumours overexpressing the maspin gene had significantly shorter relapse-free survival after surgery than patients whose tumours normally expressed or underexpressed maspin (P=0.0011). The prognostic significance of maspin overexpression persisted in Cox multivariate regression analysis (P=0.0024). These findings show that the maspin mRNA level can have important prognostic significance in human breast cancer, and point to the maspin gene as a putative molecular predictor of hormone responsiveness in breast cancer.

Deletion mapping of the tumor suppressor locus involved in colorectal cancer on chromosome band 8p21

Several somatic genetic alterations have been described in colorectal carcinoma (CRC). Recurrent chromosomal deletions have suggested the presence of tumor suppressor genes (TSG) specifically involved in colorectal carcinogenesis. For one of them, two non-overlapping regions have been proposed on the short arm of chromosome 8, encompassing the LPL and NEFL genes. The short arm of chromosome 8 has been extensively studied in colorectal cancer and in other cancer types. Both regions have been reported as candidate loci for a TSG. In order to delineate a reliable region of deletional overlap on chromosome arm 8p in CRC, a series of 365 CRC samples was selected for the absence of microsatellite instability (RER, replication error); tumor and normal matched DNAs were studied for 54 microsatellite polymorphisms distributed on 8p using multiplex-PCR amplification. After purification of tumor nuclei by flow cytometry based on either the abnormal DNA index or the presence of a high expression of cytokeratin, complete allelic losses on 8p were observed in 48% of cases. Measurement of the DNA index showed that 88% of RER tumors were hyperploid. Complete allelic losses of only part of the short arm were observed on 26 occasions. These data allowed us to define a 1 cM interval of common deletion, flanked by the loci D8S1771 and NEFL, where a putative TSG may be localized.