Cytokeratin-positive cells in bone marrow for identifying distant micrometastasis of gastric cancer.

Direct evidence of tumour seeding in distant organs at the time of surgery for gastric cancer is not available. An immunocytochemical assay for epithelial cytokeratin protein may fill this gap since it is a feature of epithelial cells that would not normally be present in bone marrow. The bone marrow of 46 patients with primary gastric cancer was examined for tumour cells, using immunocytochemical techniques and antibody reacting with cytokeratin, a component of the intracytoplasmic network of intermediate filaments. The monoclonal antibody CK2 recognises a single cytokeratin polypeptide (human cytokeratin no. 18) commonly present in epithelial cells. The expression of tumour-suppressor genes p53 and RB for the primary lesion was also determined using the monoclonal antibodies PAb 1801 and 3H9 respectively, and the proliferating activity was determined by the Ki-67 antigen labelling index for MIB-1 antibody staining. Of these 46 patients, 15 (32.6%) presented with cytokeratin-positive cells at the time of primary surgery. The positive findings were related to the undifferentiated tissue type and to the prominent depth of invasion, but not to other clinicopathological factors. In 2 of 15 (13.3%) patients, the depth of invasion was limited to the mucosa. The metastatic potential to bone marrow did not relate to expressions of p53 and RB genes, or to the proliferating activity of MIB-1 staining for the primary lesion of gastric cancer. As tumour cells in bone marrow are indicative of the general disseminative capability of an individual tumour, this technique may be useful for identifying patients at high risk of metastasis from a gastric tumour.     

Bone marrow micrometastases predict early post-operative recurrence following surgical resection of oesophageal and gastric carcinoma.

AIM: Tumour cells in the bone marrow of patients with gastrointestinal cancer may detect patients at higher risk of disease recurrence and death following potentially curative surgery. METHODS: Immunocytochemistry using the monoclonal antibody Ber-EP4, which detects tumour cells from squamous and adenocarcinomas was used. In preliminary spiking experiments to define sensitivity, tumour cells were detected in blood at 10(3)/ml. Bone marrow samples from 74 patients with oesophago-gastric cancer and from 14 control patients was examined. RESULTS: 27 (36.5%) patients with cancer and one control patient had stained cells present in their bone marrow at the time of resection. During the follow up period (mean 14 months), relapse and disease-specific death were commoner in patients whose marrow contained tumour cells. Multivariate analysis confirmed bone marrow micrometastasis as an independent prognostic variable for both recurrence and survival. CONCLUSIONS: Bone marrow immunocytochemistry using Ber-EP4 may identify those patients at highest risk of early relapse following RO resection of oesophageal or gastric cancer.     

Tumour cell detection in the bone marrow of breast cancer patients at primary therapy: results of a 3-year median follow-up.

We examined bone marrow aspirates from 100 metastasis-free primary breast cancer patients. In 38/100 patients (38%), tumour cells were detected in the marrow using an immunocytochemical technique with a cocktail of two monoclonal antibodies: anti-EMA and anti-cytokeratin. Median follow-up was 34 months: 15/38 (39%) tumour cell-positive patients have since relapsed, but only 9/62 (15%) tumour cell-negative patients. The median interval between tumour cell detection and relapse was 11.4 months. No statistically significant correlation existed between tumour cell presence and ''established'' prognostic factors. However, relapse-free survival was significantly shorter in tumour cell-positive patients. Multivariate analysis showed tumour cell presence as a strong, significant prognostic factor for relapse-free as well as overall survival. We conclude that screening for tumour cells in bone marrow of primary breast cancer patients identifies high-risk patients for early relapse. In particular, patients with node-negative tumours who have tumour cells in their bone marrow may require subsequent systemic therapy.     

Sensitivity of immunocytochemical detection of breast cancer cells in human bone marrow

We have previously shown that occult micrometastases can be detected in the bone marrow of breast cancer patients, at the time of initial treatment, using a panel of epithelial specific monoclonal antibodies indirectly labeled with fluorescein. These monoclonal antibodies permit us to detect cancer cells at at concentration of two/million normal bone marrow cells. Immunofluorescence carries the disadvantage that detailed morphological examination of detected cells cannot be accomplished. A modification of the alkaline phosphatase anti-alkaline phosphatase method has been used to detect cancer cells and to observe their morphology in human bone marrow. The sensitivity of this method has been examined using an established human metastatic breast cancer cell line (MCF-7) mixed with normal bone marrow cells at various dilutions from 400 cancer cells/10(6) marrow cells to 10 cancer cells/10(6) marrow cells. The number of immunocytochemically stained MCF-7 cells counted at each concentration was related to the concentration by a simple nonlinear statistical model. At a concentration of 10 cancer cells/10(6) bone marrow cells, the model shows that this method has the sensitivity to detect between four and six MCF-7 cells 95% of the time. Extrapolation, using this model, predicts that at the very low concentration of one cancer cell/10(6) marrow cells, there is a 95% chance of detecting the cancer cell. This assay may be a very sensitive method for detecting cancer cells in the bone marrow of breast cancer patients.     

Bone marrow micrometastases in 109 breast cancer patients: Correlations with clinical and pathological features and prognosis

Background: The presence in bone marrow of cells which react with monoclonal antibodies against tumor-associated antigens has been proposed over the last few years as a new prognostic factor in breast cancer patients. Patients and methods: Bone marrow aspirates were obtained from 109 stage I and II breast cancer patients during or 2–4 weeks after primary surgery. The samples were processed for leukocyte separation on a Ficoll-Hypaque gradient and then used to prepare cytospin slides for immunocytochemical analysis. The slides were stained with a pool of monoclonal antibodies (MoAbs) which recognize tumor associated antigens, using the alkaline phosphatase anti-alkaline phosphatase method. The median follow-up was 36 months (range 15–62); 22 patients relapsed and 7 died. Results: Thirty-four of the 109 patients (31.1%) had MoAb positive bone marrow cells. The bone marrow was positive in 28/74 (37.9%) patients who had the aspirate taken during surgery and in 6/35 (17.1%) who had it taken after surgery (p = 0.055). No association was found between bone marrow positivity and tumour size, nodal status, menopausal status, estrogen receptor positivity or the proliferative index. No association was found between bone marrow and prognosis: the log-rank test was 0.291 (p > 0.5) for OS and 0.023 for DFS; the hazard ratio (positive vs negative) was 1.51 for OS (95% CI: 0.33–6.86) and 0.93 for DFS (95% CI: 0.35–2.45). Conclusions: In our series, bone marrow positivity did not correlate with prognostic parameters or prognosis. Of interest is the relative excess of positivity when the bone marrow was obtained during surgery.     

Epithelial tumor cells in bone marrow of patients with colorectal cancer: immunocytochemical detection, phenotypic characterization, and prognostic significance.

A monoclonal antibody (mAb) directed against the cytokeratin (CK) polypeptide no. 18 specifically expressed in cells derived from simple epithelia was used to detect epithelial tumor cells in bone marrow aspirates. Of 156 patients with colorectal carcinoma, 42 presented with cells at the time of primary surgery. The incidence of positive findings varied considerably with the size and the localization of the primary tumor, the involvement of regional lymph nodes, and the presence of clinically manifest metastases. Applying a sensitive double-staining procedure, we could demonstrate that epithelial cells in bone marrow showed a heterogeneic expression of receptors for epidermal growth factor (EGF-R) and transferrin (Tf-R) as well as of the proliferation-associated Ki67 antigen. Also human leukocyte antigen (HLA) class I antigens differed widely in their expression on the CK-positive cells. Clinical follow-up studies on 85 patients showed a significantly higher relapse rate in patients presenting with CK-positive cells in their bone marrow at the time of primary surgery. Twenty-three patients were monitored for the presence or absence of CK-positive cells in bone marrow over time. The majority of monitored patients (18 of 23) exhibited a constant pattern of immunocytochemical findings during the time of observation. Thus, the technique may be useful in identifying high-risk patients as well as in monitoring adjuvant therapeutic trials.     

Monoclonal antibodies in the detection of bone marrow metastases in small cell lung cancer.

Using conventional examination (CE) of H&E stained slides from bone marrow aspirates, metastases can be detected in approximately 25% of patients with small cell lung cancer. We investigated a panel of monoclonal antibodies using immunohistochemistry in the diagnosis of bone marrow infiltration from SCLC and compared the results with CE. Seven monoclonal antibodies raised against epithelial antigens (CAM 5.2, MOV 15, NCCST 433, PE 35, LCA1/L38, HMFG 1 AND HMFG 2) were applied on bone marrow sections from three groups of patients (pts): (1) 19 pts in whom SCLC-metastases were detected by CE, (2) 44 pts with SCLC in whom metastases could not be detected by CE, and (3) 20 pts with non-malignant bone marrow diseases. All the antibodies except LCA1/L38 were positive in 60-90% of the slides with infiltrating tumour cells in group 1. No positive tumour cells were detected in group 2. A few plasma cells and megakaryocytes were slightly positive for MOV 15 and NCCST 433, but no other positive cells were detected in group 3. In conclusion, the monoclonal antibodies used in this study may be useful for diagnostic purposes when a suspicious looking infiltration is detected by CE. However, these antibodies could not detect metastatic tumour cells in the bone marrow sections from patients in whom CE did not reveal any tumour cells.     

Immunocytological detection of residual marrow disease at clinical remission predicts metastatic relapse in small cell lung cancer

A panel of monoclonal antibodies against neural and epithelial associated antigens was used to examine bone marrow from patients in clinical remission from small cell lung cancer (SCLC). A standard peroxidase-antiperoxidase technique and Ficoll-Hypaque enrichment were used to detect SCLC-like cells at the 1-2% level of contamination in 8 of 12 patients who were disease free by conventional criteria, including routine marrow cytology and histology and endobronchoscopic biopsy or cytology. Six of these patients ultimately relapsed, with metastatic sites found between 2 and 6 months after restaging. Furthermore, 6 patients had undergone chemointensification including autologous marrow rescue with radical irradiation to the primary lung tumor. Four of these 6 subsequently relapsed, also with metastatic sites. Of the 4 patients without bone marrow metastases at restaging using this technique, 2 relapsed, with cells found at the primary site, and 2 remained in complete remission. Serum free cell culture was attempted in 9 of 12 cases and SCLC-like cell colonies grew, in suspension, in 4. The SCLC-like nature of these cells has been confirmed by electron microscopy in 1 case and by repeat immunocytochemistry for small cell associated antigens in 3 cases. Bone marrow positivity using these techniques appears to predict a high risk of metastatic relapse regardless of further therapy.     

Immunocytological detection of micrometastatic cells: Comparative evaluation of findings in the peritoneal cavity and the bone marrow of gastric,colorectal and pancreatic cancer patients

The prognosis of digestive cancers is poor mainly due to intraperitoneal relapse by cells which may have already been seeded at the time of surgery. Using immunocytology we investigated the peritoneal cavity and, as a comparison, the bone marrow of 147 patients with gastric, colorectal and pancreatic cancer for micrometastatic cells. Cytological samples from peritoneal cavity lavages and bone marrow aspirates were analyzed using monoclonal antibodies (MAbs) against tumor-associated antigens (TAA) (CEA, CA-19-9, 17-1-A, C-54-0, Ra96) and compared to a MAb staining cytokeratins (KL-I). Patients with benign diseases served as controls. Intraperitoneal micrometastatic cells were detected in 27% of colorectal, 43% of gastric and 58% of pancreatic cancer patients. In the bone marrow, the corresponding data were 29% for colorectal, 25% for gastric and 58% for pancreatic cancer patients. Combined evaluation of both compartments increased the detection rate significantly (colorectal cancer: 40%, gastric cancer: 52%, pancreatic cancer: 72%). No unwarranted reactions were found in the control group. Combining 3 antibodies (CA-19-9, Ra96, C-54-0) enabled good detection for peritoneal cavity samples. In the bone marrow, the use of 2 antibodies (KL-I and CA-19-9) detected 94% of all positive samples, whereas KL-I and CA-19-9 stained approx. 70% of all positive samples in each case. The occurence of stained cells in the peritoneal cavity correlated with classical prognostic factors (TNM classification). © 1994 Wiley-Liss, Inc.     

Immunodetection of bone marrow micrometastases in breast carcinoma patients and its correlation with primary tumour prognostic features.

Methods such as immunohistochemistry that have enhanced the detection of carcinoma cells in bone marrow aspirates appear to be useful in identifying patients with aggressive tumours. To detect epithelial cells in bone marrow aspirates from breast carcinoma patients, we used a pool of five different monoclonal antibodies (MAbs), which recognise 100% of breast carcinomas, together with the alkaline phosphatase method on cytospun cells obtained from sternum and iliac crest. Primary tumours were also analysed for the expression of the c-erbB-1 and c-erbB-2 oncogene products, and of two differentiation-related markers and laminin receptors. Immunoreactive cells were detected in the bone marrow of 62 of the 197 patients tested (31%) without any correlation with clinical parameters such as tumour size or lymph node metastasis, whereas a significant (P < 0.01) correlation was found with enhanced monomeric laminin receptor expression in the primary tumour. In fact, this receptor was expressed in respectively 63% and 38% of primary tumours from patients with and without immunoreactive cells in the bone marrow aspirates. Thus, the presence of immunoreactive cells in bone marrow correlates with the expression in the primary tumour of a marker of the metastatic potential of the tumour, the 67 kDa laminin receptor.     

Implications of occult metastatic cells for systemic cancer treatment in patients with breast or gastrointestinal cancer.

The early and clinically occult spread of viable tumour cells to the organism is becoming acknowledged as a hallmark in cancer progression, since abundant clinical and experimental data suggest that these cells are precursors of subsequent distant relapse. Using monoclonal antibodies against epithelial cytokeratins or tumour-associated cell membrane glycoproteins, individual carcinoma cells can be detected in cytological bone marrow preparations at frequencies of 10(-5) to 10(-6). Prospective clinical studies have shown that the presence of such immunostained cells in bone marrow is prognostically relevant with regard to relapse-free and overall survival, even in malignancies that do not preferentially metastasise to bone. As current treatment strategies have resulted in a substantial improvement of cancer mortality rates, it is noteworthy to consider the intriguing options of immunocytochemical screening of bone marrow aspirates for occult metastatic cells. Besides improved tumour staging, such screening offers opportunities for guiding patient stratification for adjuvant therapy trials, monitoring response to adjuvant therapies (which, at present, can only be assessed retrospectively after an extended period of clinical follow-up), and specifically targeting tumour-biological therapies against disseminated tumour cells. The present review summarises the current data on the clinical significance of occult metastatic cancer cells in bone marrow.     

The presence of bone marrow cytokeratin-immunoreactive cells does not predict outcome in gastric cancer patients

The independent prognostic significance of isolated tumour cells in bone marrow is still a matter of debate. This study evaluated the possible association of bone marrow micrometastases with tumour progression and prognosis in patients affected by gastric cancer. Bone marrow aspirates from both iliac crests were obtained from 114 consecutive patients operated on for gastric cancer. The specimens were stained with monoclonal antibody CAM 5.2 which reacts predominantly with cytokeratin filaments 8 and 19. Among 114 cases analysed, 33 cases (29%) had cytokeratine-positive cells in the bone marrow. There was no significant relationship between the presence of bone marrow micrometastases and site, depth of tumour invasion, lymph node metastases, presence of metastases. Patients with cytokeratine-positive cells had a trend towards a diffuse type histology (P=0.06). Among the 88 curatively resected patients, median survivals were 40 months and 36 months for cytokeratine-negative and cytokeratine-positive subsets respectively (P=0.9). Recurrence of the disease was observed in 39 cases (44.3%); 11 of 24 (45.8%) in the cytokeratine-positive subset and 28 of 64 (43.7%) in the cytokeratine-negative subset. In conclusion in our experience the presence of cytokeratine-positive cells in the bone marrow of curatively resected gastric cancer patients did not affect outcome and its independent prognostic significance remains to be proven before its official acceptance in the TNM classification.     

Immunocytochemical monitoring of micrometastatic disease: Reduction of prostate cancer cells in bone marrow by androgen deprivation

Occult dissemination of tumor cells mainly determines the prognosis of patients with primary prostate cancer. The effect of androgen deprivation on micrometastatic tumor cells in these patients is currently unknown. We therefore used an immunocytochemical assay with monoclonal antibodies (MAbs) directed against epithelial cytoskeleton proteins (i.e., cytokeratins) to monitor the concentration of isolated tumor cells in the bone marrow of 36 prostate cancer patients (stage C), who underwent hormonal androgen deprivation with Flutamide and Leuproreline acetate. Tumor cells in cytologic bone marrow preparations were detected using an assay that employed the MAb CK2 directed against cytokeratin (CK) 18 and the alkaline anti-alkaline phosphatase staining method. Prior to therapy, we detected between 1 and 38 CK-positive cells per sample of 2 × 10⁴ nucleated cells in 21 patients, while the remaining 15 patients displayed tumor-free marrow samples. There was no significant correlation between the concentration of CK-positive cells and the volume of hypo-echogenic lesions as an indicator of the primary tumor volume or the serum level of prostate-specific antigen (PSA). After androgen deprivation, 20 of the 21 initially positive patients either became negative (n = 16) or showed at least a reduction in the concentration of CK-positive cells (n = 4). Moreover, only 2 of the 15 patients with negative pre-treatment findings became positive. All of the 7 patients with remaining tumor cells in the bone marrow after therapy showed no detectable amounts of PSA in their serum. Our findings suggest that serum PSA concentration is no indicator of micrometastatic disease in bone marrow. Neoadjuvant androgen deprivation appears to eliminate disseminated CK-positive tumor cells present in bone marrow, a preferred site of overt metastasis in prostate cancer patients. Int. J. Cancer 71:521-525, 1997. © 1997 Wiley-Liss, Inc.     

Clinical significance of proliferative potential of occult metastatic cells in bone marrow of patients with breast cancer

There is increasing statistical evidence that the presence of tumour cells in bone marrow detected by immunocytochemistry represents an important prognostic indicator in breast cancer, but their individual capacity to become clinical metastases is unknown. The aim of this study was to assess the proliferative capacity of these occult metastatic cells in the bone marrow of patients with various stages of breast cancer. We obtained bone marrow aspirates from 60 patients with breast cancer before treatment with chemotherapy: 17 stage II, 12 stage III and 31 stage IV. After bone marrow culture for 6-34 days (median: 17 days) under specific cell culture conditions, viable epithelial cells were detected by cytokeratin staining in 40 patients (66%). Expansion of tumour cells was poorly correlated with tumour cell detection on primary screening (P=0.06). There was a nonsignificant correlation between the number and the presence of expanded tumour cells and the UICC stage of the patients. On primary screening, tumour cell detection was positive in 56% of patients and was correlated with clinical UICC stage (P=0.01). However, with a median follow-up of 23 months, expansion of tumour cells from bone marrow was associated with decreased patient survival (P=0.04), whereas the survival difference according to detection of CK-positive cells on primary screening was not statistically significant. In conclusion, viable tumour cells can be detected in the bone marrow of breast cancer patients. Their proliferative potential could be predictive of outcome and deserves further investigation.     

Effective removal of SCLC cells from human bone marrow. Use of four monoclonal antibodies and immunomagnetic beads.

High dose chemotherapy with autologous bone marrow transplantation (ABMT) has shown promise in several types of cancer. There is, however, a risk of transfusing contaminating tumour cells with the bone marrow cells, e.g. in patients with small cell lung carcinoma (SCLC). To eliminate SCLC cells from normal human bone marrow, four monoclonal antibodies reactive with SCLC cells were used with immunomagnetic beads in model experiments. With two cycles of immunomagnetic elimination the individual antibodies removed 2.5-4.4 log of H-146 tumour cells from a single cell suspension, as assessed in a highly reproducible soft agar assay. Different combinations of two antibodies were only marginally more effective than the individual MAbs, whereas 5-6 log removal was obtained with a combination of all four antibodies. The method was equally effective when the tumour cells were mixed with bone marrow cells at a ratio of 1:10. The immunomagnetic procedure did not significantly affect the survival of normal progenitor cells, assessed in CFU-GM and CFU-GEMM assays. The results indicate that the procedure safely and effectively can be used to eliminate tumour cells from the bone marrow in conjunction with ABMT in patients with SCLC.     

Examination of bone marrow biopsy specimens and staging of small cell lung cancer

Bone marrow biopsy specimens were evaluated retrospectively in 63 of 88 (72%) patients with small cell lung cancer (SCLC). Significant differences were not found between extensive disease (ED) patients with or without bone marrow metastases in survival nor in nadirs of leucocytes or platelets subsequent to chemotherapy. A panel of antibodies was used to investigate whether immunohistochemical analysis on routinely processed bone marrow biopsy specimens could detect marrow metastases more effectively than conventional microscopy. In histologically proven marrow metastases and in control SCLC sections a combination of an antibody against cytokeratin 8, 18 and 19 (NCL5D3) and an antibody against neurone specific enolase was validated for detection of metastases. In histologically negative marrow biopsy samples, however, this combination did not yield any additional tumour positive cases. Therefore, histological evaluation of a bone marrow biopsy specimen, even when analysed by immunohistochemistry, does not contribute information relevant for staging, therapy evaluation or prognosis in SCLC.     

Clinical relevance of circulating tumour cells in the bone marrow of patients with SCCHN

BACKGROUND: Clinical outcome of patients with head and neck squamous cell carcinoma (SCCHN) depends on several risk factors like the presence of locoregional lymph node or distant metastases, stage, localisation and histologic differentiation of the tumour. Circulating tumour cells in the bone marrow indicate a poor prognosis for patients with various kinds of malignoma. The present study examines the clinical relevance of occult tumour cells in patients suffering from SCCHN. PATIENTS AND METHODS: Bone marrow aspirates of 176 patients suffering from SCCHN were obtained prior to surgery and stained for the presence of disseminated tumour cells. Antibodies for cytokeratin 19 were used for immunohistochemical detection with APAAP on cytospin slides. Within a clinical follow-up protocol over a period of 60 months, the prognostic relevance of several clinicopathological parameters and occult tumour cells was evaluated. RESULTS: Single CK19-expressing tumour cells could be detected in the bone marrow of 30.7% of the patients. There is a significant correlation between occult tumour cells in the bone marrow and relapse. Uni- and multivariate analysis of all clinical data showed the metastases in the locoregional lymph system and detection of disseminated tumour cells in the bone marrow to be statistically highly significant for clinical prognosis. Conclusion: The detection of minimal residual disease underlines the understanding of SCCHN as a systemic disease. Further examination of such cells will lead to a better understanding of the tumour biology, as well as to improvement of diagnostic and therapeutic strategies.     

Analysis of and prognostic information from disseminated tumour cells in bone marrow in primary breast cancer: a prospective observational study

ABSTRACT: BACKGROUND: Disseminated tumour cells (DTCs) in the bone marrow of patients with breast cancer have been identified as an independent predictor of poor prognosis in patients with non-metastatic disease. This prospective study aimed to evaluate the presence and prognostic value of DTCs in the bone marrow of female patients with primary breast cancer. METHODS: Between 1999 and 2003, bone marrow aspirates were obtained from patients at the time of surgery for primary invasive breast cancer. DTCs in bone marrow were identified using monoclonal antibodies against cytokeratins for detection of epithelial cells. The detection of DTCs was related to clinical follow-up with distant disease-free survival (DDFS) and breast cancer-specific survival as endpoints. Bone marrow aspirates from adult healthy bone marrow donors were analysed separately. RESULTS: DTCs were analysed in 401 patients, and cytokeratin-positive cells were found in 152 of these (38%). An immunofluorescence (IF) staining procedure was used in 327 patients, and immunocytochemistry (IC) was performed in 74 patients. The IF-based method resulted in 40% DTC-positive cases, whereas 30% were positive using IC (p = 0.11). The presence of DTCs in bone marrow was not significantly related to patient or tumour characteristics. The presence of DTCs was not a prognostic factor for DDFS (IF: hazards ratio [HR], 2.2; 95% confidence interval [CI], 0.63--2.2; p = 0.60; IC: HR, 0.84; 95% CI, 0.09--8.1; p = 0.88). Significant prognostic factors were lymph node metastases, oestrogen receptor positivity, Nottingham histological grade, and tumour size using Cox univariate analysis. The analyses were positive for epithelial cells in bone marrow from adult healthy donors in 19 (25%) samples. CONCLUSIONS: The detection of DTCs in bone marrow in primary breast cancer was previously shown to be a predictor of poor prognosis. We were not able to confirm these results in a prospective cohort including unselected patients before the standard procedure was established. Future studies with a standardised patient protocol and improved technique for isolating and detecting DTCs may reveal the clinical applications of DTC detection in patients with micrometastases in the bone marrow.