Indications and results of diagnostic biopsy in pediatric renal tumors: A retrospective analysis of 317 patients with critical review of SIOP guidelines

OBJECTIVES

According to the Renal Tumor Study Group (RTSG) of the International Society of Paediatric Oncology (SIOP), diagnostic biopsy of renal tumors prior to neoadjuvant chemotherapy is not mandatory unless the presentation is atypical for a Wilms tumor (WT). This study addresses the relevance of this strategy as well as the accuracy and safety of image-guided needle biopsy.

METHODS

Clinical, radiological, and pathological data from 317 children (141 males/176 females, mean age: 4 years, range, 0-17.6) consecutively treated in one SIOP-affiliated institution were retrospectively analyzed.

RESULTS

Presumptive chemotherapy for WT was decided for 182 patients (57% of the cohort), 24 (8%) were operated upfront, and 111 (35%) were biopsied at diagnosis. A non-WT was confirmed after surgery in 5/182 (3%), 11/24 (46%), and 28/111 (25%), respectively. Age at diagnosis was the most commonly (46%) used criterion to go for biopsy but a nine-year threshold should be retrospectively considered more relevant. Tumor volumes of clear cell sarcoma of the kidney and WT were significantly higher than those of other tumors (P = 0.002). The agreement between core-needle biopsy (CNB) and final histology was 99%. No significant morbidity was associated with CNB.

CONCLUSION

The use of SIOP criteria to identify patients eligible for presumptive WT neoadjuvant chemotherapy or upfront surgery avoided biopsy in 65% of children and led to a 97% rate of appropriate preoperative chemotherapy. Image-guided CNB is a safe and accurate diagnostic procedure. The relevance of SIOP biopsy criteria might be improved by using an older age threshold (9 years instead of 6 years) and by adding initial tumor volume.

hSNF5/INI1-deficient tumours and rhabdoid tumours are convergent but not fully overlapping entities

Rhabdoid tumours (RTs) are rare but highly aggressive tumours of childhood. Their rarity and their miscellaneous locations make the diagnosis particularly challenging for pathologists. Central nervous system and peripheral RTs have been associated with biallelic inactivation of the hSNF5/INI1/SMARCB1 (hSNF5/INI1) tumour suppressor gene. Immunohistochemistry (IHC) with a monoclonal anti-hSNF5/INI1 antibody has recently been proposed as an efficient diagnostic tool for RTs. We have conducted a retrospective study of 55 tumours referred to our institution with a suspicion of RT. This analysis included pathological review, IHC with anti-hSNF5/INI1 antibody, and molecular investigation using quantitative DNA fluorescent analysis and sequencing of the nine exons of hSNF5/INI1. The molecular lesion could be detected in 37 of the 39 cases exhibiting negative staining for hSNF5/INI1. In the two discrepant cases, the lack of detection of genetic abnormality was probably owing to the presence of a high number of non-tumour cells in the samples. This indicates that hSNF5/INI1 IHC is very sensitive and highly specific for the detection of hSNF5/INI1 loss-of-function. Among the 38 cases with typical RT histological features, six failed to exhibit hSNF5/INI1 mutation and stained positive for hSNF5/INI1. This strongly supports the evidence of a second genetic locus, distinct from hSNF5/INI1, associated with RT. Conversely, seven tumours with histological features poorly compatible with RT stained negative for hSNF5/INI1; they nevertheless exhibited an age of onset and a clinical behaviour similar to RT. This suggests that hSNF5/INI1 inactivation is not strictly limited to typical RT but characterizes a wider family of hSNF5/INI1-deficient tumours. Consequently, we believe that anti-hSNF5/INI1 IHC should be performed widely, even when the pathological characteristics are not typical. The molecular investigation should be performed in infants when a rhabdoid predisposition syndrome is suspected.

HER2 status of bone marrow micrometastasis and their corresponding primary tumours in a pilot study of 27 cases: a possible tool for anti-HER2 therapy management?

Discrepancies have been reported between HER2 status in primary breast cancer and micrometastatic cells in bone marrow. The aim of this study was to assess HER2 gene status in micrometastatic cells in bone marrow and corresponding primary tumour. Micrometastatic cells were detected in bone marrow aspirations in a prospective series of 27 breast cancer patients by immunocytochemistry (pancytokeratin antibody). HER2 status of micrometastatic cells was assessed by fluorescence in situ hybridisation (FISH), respectively in 24 out of 27. Primary tumour HER2 status was assessed by immunohistochemistry (CB11 antibody) and by FISH in 20 out of 27 of the cases. HER2 was amplified or overexpressed in five out of 27 (18.5%) primary tumours and in four out of 27 (15%) micrometastatic cells. In two cases, HER2 was overexpressed and amplified in primary tumour, but not in micrometastatic cells, whereas, in one case, HER2 presented a low amplification rate (six copies) in micrometastatic cells not found in the primary tumour. We demonstrated that negative and positive HER2 status remained, in the majority of the cases, stable between the bone marrow micrometastasis and the primary tumour. Therefore, the efficiency of anti-HER2 adjuvant therapy could be evaluated, in a clinical trial, by sequential detection of HER2-positive micrometastatic cells within the bone marrow, before and after treatment.

Analysis of correlation between mitotic index, MIB1 score and S-phase fraction as proliferation markers in invasive breast carcinoma. Methodological aspects and prognostic value in a series of 257 cases

BACKGROUND

The study was designed in order to evaluate the degree of correlation of mitotic index (MI), Ki67 (MIB1) score and S-phase fraction (SPF) as markers of cell proliferation and prognosis in breast cancer.

MATERIALS AND METHODS

The series analysed corresponded to 257 consecutive invasive breast carcinoma, treated at the Institut Curie, France, in 1995. Nottingham histological grade and MIB1 semiquantitative and quantitative score were assessed on histological sections, whereas SPF was calculated using flow cytometry analysis of fine-needle aspiration products. Proliferation indices were compared to pathological data and to overall survival (OS) and disease-free survival (DFS) (minimum follow-up: 72 months).

RESULTS

The median values for the proliferation markers were 9/10 HPF for MI, 32.4% for MIB1 and 3.7% for SPF. A high rate of correlation (r=0.96; p<0.001) was observed between semi-quantitative and quantitative MIBI evaluation. A positive correlation was found between the three markers (r ranging from 0.54 to 0.61;p<0.001). Univariate analysis of markers associated to disease outcome showed that MIB1, axillary node status (N) and progesterone receptor (PR) status were significantly associated with OS and that MIB1 and SPF were associated with DFS, together with node and hormone receptor status. In multivariate analysis, when proliferation markers were adjusted on the N and PR status, only MIB1 retained a prognostic value for OS (RR= 1.83) [1.00;3.35] and SPF for DFS (RR= 1.58) [1.02-2.44] (p=0.04).

CONCLUSION

A good level of correlation was observed between the values of the three markers of tumour cell proliferation analysed. In this series of invasive breast cancers, MIB1 immunostaining was found to be a prognostic marker of both OS and DFS. The median (32.4%) was a valuable cut-off value for prognostic assessment. Semi-quantitative and quantitative evaluations provided very similar values. MIB1 can thus be considered as a reliable prognostic maker, usable in small size tissue specimens which are inappropriate for MI or SPF analysis. The impact of MIB1 compared to that of the other proliferative markers will be further assessed in a subgroup of T1N0M0 for which the prognostic assessment is of major interest.

Increased cell size and Akt activation in HER-2/neu-overexpressing invasive ductal carcinoma of the breast

AIMS

To determine whether cell size is related to HER-2/neu status and/or to Akt activation in breast carcinomas. HER-2/neu overexpression is observed in 20-30% of invasive breast carcinomas with poor pronostic features, but little is known about the cell phenotype associated with HER-2/neu activation. Akt has been found to be involved in the HER-2/neu signal transduction pathway and Akt activation has been associated with increased cell size in various models.

METHODS AND RESULTS

A case-control study of invasive ductal carcinoma of the breast was carried out, including 21 cases displaying HER-2/neu overexpression and 20 HER-2/neu negative controls. Cytoplasmic and nuclear sizes were measured on digitized histological pictures using cell image analysis software. Akt expression analysis was performed by immunohistochemistry on formalin-fixed histological sections using an anti-phosphorylated-Akt (Ser473) antibody.

RESULTS

HER-2/neu-overexpressing carcinomas had a mean nuclear size of 75 +/- 22.2 micro m(2) and a mean cytoplasmic size of 187 +/- 52.3 micro m(2). Both values were higher than the nuclear and cytoplasmic size of HER-2/neu-negative cases (nucleus = 58 +/- 24.5 micro m(2), cytoplasm = 133 +/- 56.6 micro m(2); P = 0.02 and P =0.003, respectively). Up to 75% of the tumours with a cell size over 140 micro m(2) were HER-2/neu-positive. Immunohistochemical Akt expression was observed in 19/40 (47.5%) cases. The immunoreactivity was localized in the cytoplasm in eight cases, on the cell membrane in four cases and at both sites in seven cases. One case was not interpretable. Comparison between HER-2/neu and Akt status showed that Akt was detectable at the cell membrane in 43% (9/21) of HER-2/neu-positive and in 10% (2/19) of HER-2/neu-negative cases (P = 0.02).

CONCLUSIONS

HER-2/neu overexpression was consistently associated with increased cell size in invasive ductal carcinoma of the breast. This increase may be related to concomitant Akt activation. The assessment of activated pathways in HER-2/neu-overexpressing breast carcinomas may provide useful information for optimized individual HER-2/neu-targeted therapy.

Wide metastatic spreading in infiltrating lobular carcinoma of the breast

The aim of this study was to determine whether the metastatic potential of breast cancer could be related to phenotypic characteristics of the tumour. Therefore, we compared the metastatic patterns of invasive lobular (ILC) and ductal (IDC) carcinomas. In ILC, we also analysed this pattern according to the histological subtype of the primary and the E-cadherin (EC) expression level. Metastatic ILC cases (n=96) were retrospectively analysed and classified into classical, alveolar, solid, tubulo-lobular, signet ring cells or pleomorphic subtypes. Anatomical distribution of metastases was detailed for every patient and compared with that registered for IDC (n=2749). Immunostaining of EC (HECD1 antibody) was performed in 82 cases. Histologically, 78 of the 96 cases (81%) corresponded to classical ILC. The pleomorphic subtype was observed in 14 cases (15%), a rate that was higher than that expected. Others corresponded to alveolar (2 cases), signet ring cell (1 case) and solid (1 case) subtypes. EC was undetectable in 72/82 cases (88%). The rate of multiple metastases was higher in ILC (25.0%) than in IDC (15.8%) (P=0.016). Metastases were found more frequently in ILC than in IDC in the bone (P=0.02) and/or in various other sites (peritoneum, ovary, digestive tract, skin em leader ) (P<0.001). In ILC, no significant link was found between the localisation(s) of metastases, the histological subtype and the EC status in the primary. In conclusion, in breast carcinomas, the frequency of multiple metastasis was found to be higher in ILC than IDC. This fact may be related to the phenotypic trait of discohesive small cells which characterises ILC. EC loss, observed in most cases of ILC, may result in alterations in cell-cell adhesion and a preferential growth at metastatic sites. A high rate of pleomorphic tumours was observed in the group of metastatic ILC, but the pattern of metastatic site(s) was not related to the histological subtype of the primary.

[Histological margin and residual disease assessment for breast carcinoma]

Margin and histological size of ductal in situ carcinoma or intraductal component of an infiltrative carcinoma are important prognostic factors to predict presence/absence as well as amount of residual tumor burden. Their evaluation requires standardized pathological analysis. These factors should be interpreted in clinical and radiological context.

Prediction of tumour involvement in remaining axillary lymph nodes when the sentinel node in a woman with breast cancer contains metastases

Background

In a significant proportion of women with breast cancer, the sentinel node is the only involved node in the axilla. The purpose of this study was to identify factors associated with histologically positive non-sentinel lymph nodes.

Methods

Between 1997 and 2002, 800 women with early breast cancer underwent sentinel node biopsy. In 263 patients the node contained metastases, including 83 with micrometastases detected by immunohistochemistry (IHC), 40 micrometastases detected on haematoxylin, eosin and safranine (HES) staining, and 140 macrometastases. All clinical and histological criteria were recorded and analysed with reference to histology of the non-sentinel node.

Results

The risk of metastasis in the non-sentinel lymph node was related to the volume of the tumour in the sentinel node. Non-sentinel nodes were involved in five (6·0 per cent) of 83 women when the sentinel node contained only micrometastatic cells detected on IHC, and in three (7·5 per cent) of 40 women when micrometastases were detected by HES, compared with 55 (39·3 per cent) of 140 when the sentinel node contained macrometastases on HES staining. Univariate analysis revealed a significant association between non-sentinel node involvement and type of metastasis within the sentinel node, clinical primary tumour size, palpable axillary lymph nodes before operation, pathological primary tumour size and the presence of peritumoral lymphovascular invasion. On multivariate analysis, the type of metastasis within the sentinel node (P &lt; 0·001), histological tumour size greater than 20 mm (P = 0·017) and the presence of palpable axillary nodes before operation (P = 0·014) remained significant.

Conclusion

Clinical and pathological factors associated with sentinel node histology can reliably predict women for whom further axillary clearance is recommended, but it is not yet possible to determine a subgroup of patients in whom the sentinel node is the only involved node and for whom further axillary treatment may be unnecessary.

Long term outcome of small size invasive breast carcinomas independent from angiogenesis in a series of 685 cases

BACKGROUND

To document the role of neoangiogenesis in the progression of breast carcinomas, intratumoral vascular density (ITVD) was assessed and compared to pathologic data and disease outcome in a series of 685 cases.

METHODS

Patients were registered between 1981 and 1988 at the Curie Institute. Tumors corresponded to small size (< or = 30 mm) invasive carcinomas, 71% of which were axillary lymph node-negative. In all cases, conservative surgery was the initial therapeutic procedure. The median follow-up was 10.8 years. ITVD was retrospectively determined as the number of immunostained (anti-F8RA/vWF antibody) vessels in an area of 1.2 mm(2). The prognostic value of ITVD regarding overall survival, locoregional recurrence-free, and metastasis-free intervals was assessed in uni- and multivariate analyses.

RESULTS

Microvessel count ranged from 5--245 per 1.2 mm(2) field. The median value was 62, and the mean was 67. The median was chosen as a cut point for statistical analysis. ITVD was found to be inversely linked to tumor size (P < or = 0.0001) and histologic grade (P = 0.005), and directly linked to vascular invasion (P = 0.02). In uni- and multivariate analysis, no significant link was found between ITVD and disease outcome, even after adjustment on histologic grade and tumor size.

CONCLUSIONS

ITVD was inversely correlated to tumor size and histologic grade in our series of small-size breast carcinomas. No significant link between ITVD and disease outcome was observed. Evaluation of the role of angiogenesis in tumor progression should be based on the discriminative assessment of mature and/or activated vessels.

Sentinel lymph node detection for breast cancer: which patients are best suited for the patent blue dye only method of identification?

BACKGROUND

The objectives of this study were, first, to define the preoperative criteria for using solely the blue dye method and, second, to decrease its operator dependence in predicting axillary lymph node status.

METHODS

Two hundred fifty-three women consecutively identified with operable breast cancer underwent sentinel lymph node (SLN) detection by the patent blue dye method followed by completion axillary lymph node dissection. A standard pathological examination was performed for all SLN. Then, a pathological color quality assessment (PCQA), which checked for the presence of the blue dye, was performed on the paraffin blocks of the nonmetastatic SLN. Six preoperative identifiable variables likely to influence the detection rate were examined.

RESULTS

The surgical detection (sd) rate was 84% (213 of 253) and the PCQA rate was 73% (185 of 253). Only breast size (sd, P = .0005; PCQA, P = .0007) and body mass index < or =30 (sd, P = .005; PCQA, P = .0007) were significant for SLN identification. Multivariate analysis revealed two independent factors influencing SLN identification: breast size (sd, P = .0001; PCQA, P = .002) and the timing of injection-injection prior to lumpectomy (sd, P = .04).

CONCLUSIONS

The optimal patient features for identifying the SLN by the patent blue dye method are small or medium-sized breasts, low body fat, and that the procedure is carried out prior to tumor excision. The PCQA offers a useful second assessment of the surgically removed SLN, introducing an independent element of quality control.

[Value of macroscopic analysis for authentification of axillary sentinel nodes detected by Patent Blue dye alone during breast cancer surgery]

Assessment sentinel node coloration by the patent blue dye technique during breast carcinoma surgery largely depends upon the surgeon. It would therefore be valuable to define a procedure to validate the quality of the surgical specimen. With this aim, we have analyzed a series of 141 cases of sentinel nodes and determined whether the blue color of the node persisted after formalin fixation and could be assessed by examination of the tissue blocks. The pathologist's macroscopic control confirmed blue coloring in 114/141 cases (81%). This rate was similar when the sentinel node was metastatic (82.5%) (40 cases) or non metastatic (81%) (101 cases). Checking the color of the lymph node is a simple method to verify the quality of the surgical specimen. This item should be included in the pathologist's report. Several mechanisms can account for the lack of coloring of true sentinel nodes.

The RB1 gene is the target of chromosome 13 deletions in malignant fibrous histiocytoma

Forty-four malignant fibrous histiocytomas (MFHs) were studied by comparative genomic hybridization. Among the observed imbalances, losses of the 13q14-q21 region were observed in almost all tumors (78%), suggesting that a gene localized in this region could act as a tumor suppressor gene and that its inactivation could be relevant for MFH oncogenesis and/or progression. We determined by CA repeat analyses a consensus region of deletion focusing on the RB1 region. The RB1 gene was then analyzed by protein truncation test, direct sequencing, fluorescence in situ hybridization, Southern blotting, and immunohistochemistry. RB1 mutations and/or homozygous deletions were found in 7 of the 34 tumors analyzed (20%). Among the 35 tumors with comparative genomic hybridization imbalances analyzed by immunohistochemistry, 30 (86%) did not exhibit significant nuclear labeling. The high correlation between chromosome 13 losses and absence of RB1 protein expression and the mutations detected strongly suggest that RB1 gene inactivation is a pivotal event in MFH oncogenesis. Moreover, the observation of a high incidence of MFH in patients previously treated for hereditary retinoblastoma fits well this hypothesis.

[Sentinel lymph node detection in breast cancer. Experience of the Institut Curie]

Sentinel lymph node biopsy is a recently developed, minimally invasive technique for staging the axilla in breast cancer. This new procedure of selective lymphadenectomy has been the subject of several studies, and a consensus of opinion is starting to form to define indications and methods of identification concerning the use of this technique. At the Institut Curie since 1996, we have been using the Patenté blue dye technique and from 1998 we have used the combination of blue dye and technetium labeled sulfur colloid. This article summarizes the principales aspect of this technique.