Gastric cancer with p53 overexpression has high potential for metastasising to lymph nodes.

Overexpression of the tumour suppressor gene p53 was investigated immunohistochemically in 96 primary gastric carcinomas and 26 corresponding metastatic perigastric lymph nodes. Abnormalities in p53 expression were found in 52 (54%) of the 96 primary carcinomas. Tumours stained positively for p53 frequently metastasised to lymph nodes (the metastatic rate: 85%) compared to findings in those with negative p53 staining (64%, P < 0.05). Ninety-two percent (24/26) of the malignant cells in the lymph nodes stained positively for p53. When the DNA ploidy pattern of the tumour was determined by flow cytometry, the aneuploid tumours in p53 positive and negative groups accounted for 69% and 45%, respectively (P < 0.05). Proliferative activity of the tumour, as measured by Ki-67 labelling, was significantly higher (30.6 +/- 12.0%) in the p53 positive group than that (25.1 +/- 10.7%) in the p53 negative group (P < 0.05). Thus, gastric cancer with a mutant p53 has high proliferative activity and metastasis to lymph nodes will probably occur.     

Correlation between sialyl Tn antigen and lymphatic metastasis in patients with Borrmann type IV gastric carcinoma.

The expression of sialyl Tn (STn) antigen in 180 patients with Borrmann type IV gastric carcinomas was examined immunohistochemically. The rate of positive STn staining was 32% (57/180) for the primary tumours, and this positive staining correlated well with tumour extension, lymph node metastasis (P < 0.05) and peritoneal dissemination (P < 0.01). One-third (5/15) of patients with positive STn-staining cancer cells had a high level of serum STn. Lesions with positive STn staining were related to a lower survival rate for the patients (P < 0.05). Proliferative activity of the tumour, as measured by proliferating nuclear antigen (PCNA) labelling percentage and argyrophilic nucleolar organiser region (AgNOR) count, was significantly higher (41.5 +/- 13.0%, 3.78 +/- 0.98) in the STn-positive group than in the STn-negative group (34.2 +/- 13.2%, 3.48 +/- 0.85) (P < 0.01, P < 0.05 respectively). Estimating STn antigen may be useful for predicting the likelihood of lymph node metastasis or peritoneal dissemination and the clinical prognosis for patients with Borrmann type IV gastric carcinoma.     

Assessment of the new proliferation marker MIB1 in breast carcinoma using image analysis: associations with other prognostic factors and survival.

The ''growth fraction'' of tumours can now be assessed on paraffin sections of tissues using the monoclonal antibody MIB1 by a microwave antigen retrieval technique. The MIB1 labelling index was studied using a CAS 200 image analyser in 177 tumours from women with primary operable breast carcinoma in whom long-term follow-up data were known. Statistical analysis showed a strong association between the MIB1 labelling index and histological grade (P < 0.001), tumour size (P = 0.002), tumour type (P < 0.001) and also patient survival (P < 0.001). No association with lymph node stage (P = 0.974) or regional recurrence (P = 0.185), the presence or absence of distant metastases (P = 0.418), patient age (P = 0.309), menopausal status (P = 0.181) or oestrogen receptor status (P = 0.401) was found in this group of patients. In multivariate analysis for survival, when histological grade, lymph node stage and tumour size were included as well as the MIB1 labelling index, each was found to be of independent significance. If histological grade was not included, MIB1 replaced it as the most important variable predicting for survival in this group of patients. The results suggest that the tumour growth fraction, as assessed by the MIB1 labelling index, is an important predictor of survival.     

Overexpression of cyclin D1 correlates with early recurrence in superficial bladder cancers.

Cyclin D1 is a cell cycle regulator essential for G1 phase progression and is frequently overexpressed in several human tumour types as a consequence of gene amplification or chromosomal rearrangements. We analysed the expression of cyclin D1 in 75 patients with transitional cell carcinoma (TCC) to investigate the possible relationship between its expression and clinical outcome as well as histopathological findings using the immunohistochemical method. We observed strong staining (++, > 50% positive cells) for cyclin D1 in 19 cases (25.3%) and weak staining (+, 5-50% positive cells) in 19 cases (25.3%). Overexpression of cyclin D1 was not associated with tumour invasion. No significant association was found between overexpression of cyclin D1 and tumour grade (P > 0.05). We assessed the differences of disease-free interval in superficial tumours and actuarial survival probability in invasive tumours according to the status of cyclin D1 expression. Tumours with (++) staining for cyclin D1 recurred much more rapidly than (-) and/or (+) staining tumours (P < 0.01 for - vs ++; P < 0.05 for + vs ++). However, overexpression of cyclin D1 was not associated with a shortened overall survival of patients with invasive tumours (P < 0.1). These results suggest that genetic alteration of cyclin D1 appears to be an early event in the tumorigenesis of bladder TCC and is associated with early recurrence in superficial tumours.     

Expression of vascular endothelial growth factor (VEGF) in epithelial ovarian neoplasms: correlation with clinicopathology and patient survival, and analysis of serum VEGF levels.

Vascular endothelial growth factor (VEGF) is known to be produced by various solid tumours and is thought to be involved in microvascular permeability and/or angiogenesis. To examine the relationship between VEGF expression in ovarian neoplasms and clinicopathological factors or patient survival, expression of VEGF was analysed immunohistochemically in 110 epithelial ovarian tumours. In addition, VEGF levels in the tumour fluid (17 patients), ascites (12 patients) and sera (38 patients) were determined using enzyme immunoassay. Positive immunostaining for VEGF was observed in 97% (68 out of 70) of ovarian carcinomas, which was significantly higher than that of tumours of low malignant potential (LMP) (13 out of 25; 52%) and benign cystadenomas (5 out of 15; 33%) (P < 0.01). In ovarian carcinomas, strong VEGF immunostaining was also observed more frequently in tumours of clear cell type (P < 0.05) in the advanced stage of disease (P < 0.05) and with positive peritoneal cytology (P < 0.01). Patients with strong VEGF staining had poorer survival rates than those with weak or no immunostaining for VEGF (P < 0.01). These findings suggest that strong VEGF expression plays an important role in the tumour progression of ovarian carcinoma. The enzyme immunoassay revealed higher serum VEGF levels in carcinoma patients than those in patients with LMP or benign tumours (P < 0.01). Serum VEGF levels decreased after the successful removal of tumours in ovarian cancer patients and, in one patient, the serum VEGF level was re-elevated during relapse. Therefore, serum VEGF could be used as a marker for monitoring the clinical course of ovarian cancer patients.     

Allelotype of squamous cell carcinoma of the head and neck: fractional allele loss correlates with survival.

Allelic imbalance or loss of heterozygosity (LOH) studies have been used extensively to identify regions on chromosomes that may contain putative tumour-suppressor genes. We have undertaken an extensive allelotype of 80 specimens of squamous cell carcinoma of the head and neck (SCCHN) using 145 polymorphic microsatellite markers on 39 chromosome arms. Allelic imbalances were found most frequently on chromosome arms 3p, 9p, 17p and 18q with over 45% LOH and imbalances on 1p, 1q, 2p, 5q, 6p, 6q, 8p, 8q, 9q, 11q, 13q, 17q and 19q were found in more than 20% of SCCHN. These LOH data were analysed against a range of clinicopathological parameters which included previously untreated and previously treated tumours; correlations were found between LOH on 9q and nodes at pathology (P = 0.02) and between histopathological grade and LOH on 12q (P = 0.02) and 13q (P = 0.01). In the group of previously untreated tumours, a correlation was found between site of tumour and LOH on 3p (P = 0.019), and 8p (P = 0.029), while TNM staging correlated with LOH on 3p (P = 0.019) and 17p (P = 0.016). Fractional allele loss (FAL) was calculated for 52 tumours with LOH data on nine or more chromosomal arms and found to have a median value of 0.22 (range 0.0-0.80). Correlations were found between FAL > median value and nodes at pathology (P = 0.01) and tumour grade (P = 0.06), demonstrating that advanced tumours with lymph node metastasis often had LOH at multiple sites. FAL > median value was found to correlate with a poor survival (P < 0.03) and, furthermore, FAL > median value correlated with poor survival in the previously untreated patients (P < 0.019). These results indicate that assessment of the accumulation of genetic damage, as provided by allelotype data, provides a useful molecular indicator of the tumour behaviour and clinical outcome.     

Expression of Bcl-2 in node-negative breast cancer is associated with various prognostic factors, but does not predict response to one course of perioperative chemotherapy.

The aim of this study was to assess relationships between Bcl-2 expression, response to chemotherapy and a number of pathological and biological tumour parameters in premenopausal, lymph node-negative breast cancer patients. Expression of Bcl-2 was determined using immunohistochemistry on paraffin-embedded sections in a series of 441 premenopausal, lymph node-negative breast cancers of patients randomised to receive perioperative chemotherapy (5-fluorouracil, doxorubicin, cyclophosphamide) or no perioperative chemotherapy. Immunohistochemistry of Bcl-2 was evaluated by scoring both staining intensity (0-3) and number of positive cells (0-2). Using these scores tumours were grouped into categories 0-6. It was found that 9.2% of the tumours were completely negative (0), 17.2% weakly (1 + 2), 41.6% moderately (3 + 4) and 31.9% strongly positive (5 + 6) for Bcl-2. A positive correlation was found between high Bcl-2 expression and oestrogen (P < 0.001) and progesterone receptor positivity (P < 0.001) and low tumour grade (P < 0.001), whereas high Bcl-2 expression was negatively correlated with p53 (P < 0.001) and c-erb-B-2 positively (P < 0.001), high Ki-67 index (P < 0.001), mitotic index (P < 0.001) and large tumour size (P = 0.006). Patients with tumours expressing high levels of Bcl-2 (overall score 3-6) had a significantly better disease-free (P = 0.004) and overall (P = 0.009) survival. However, in a multivariate model this association no longer remained significant. There was a trend for an effect of adjuvant chemotherapy on disease-free survival both for patients with Bcl-2-positive (HR-0.61, 95% CI 0.35-1.06, P = 0.07) and negative (HR = 0.55, 95% CI 0.27-1.12, P = 0.09) breast tumours at a median follow-up of 49 months. The level of Bcl-2 expression does not seem to predict response to perioperative chemotherapy in premenopausal, lymph node-negative breast cancer patients. High levels of Bcl-2 are preferentially expressed in well-differentiated tumours and are associated with favourable prognosis. However, Bcl-2 expression is not an independent prognostic factor in this patient series.     

Expression of tissue inhibitor of metalloproteinases TIMP-2 in human colorectal cancer--a predictor of tumour stage.

The aim of this study was to investigate whether immunohistochemical staining patterns of tissue inhibitor of metalloproteinases TIMP-2 and matrix metalloproteinases MMP-2 and MMP-9 can be predictors of tumour stage and survival time in colorectal cancer. Frozen tumour sections from 212 patients operated on between January 1987 and November 1990 were investigated. Three mouse monoclonal antibodies--T2-101 against TIMP-2, CA-4001 against MMP-2 and GE-213 against MMP-9--were used. Positive expression of TIMP-2 (a) in basement membranes and (b) diffusely in stroma with (c) subglandular enhancement was found significantly (P < 0.01, P < 0.05, P < 0.05) more often in localized tumours than in tumours with regional or distant metastases. Neither pattern correlated with tumour differentiation. Patterns (a) and (c) correlated with longer survival time (P < 0.05); (b) reached near significance (P < 0.07). When the survival analyses were restricted to potentially cured patients, neither pattern could foretell death from cancer. Positive expression of MMP-2 in tumour epithelium and of MMP-9 in tumour-infiltrating macrophages were both independent of tumour stage and were without correlation with survival time. A large number of MMP-9-positive macrophages correlated (P < 0.05) with poor tumour differentiation, whereas weak or absent epithelial MMP-2 staining reached near significance (P < 0.08). Exploration of TIMP-2 expression is valuable for the discrimination between macroscopically localized and metastatic colorectal cancer, but it cannot predict which of the potentially cured patients are likely to have micrometastases. MMP-2 and MMP-9 stainings are of minor value in staging and prognostic prediction.     

Prostate-specific antigen and gross cystic disease fluid protein-15 are co-expressed in androgen receptor-positive breast tumours.

Androgens regulate breast cancer cell proliferation via androgen receptor (AR)-mediated mechanisms. To investigate further the androgen-responsiveness of human breast tumours, we examined the immunohistochemical expression of the AR and two androgen-regulated proteins, prostate-specific antigen (PSA) and gross cystic disease fluid protein-15 (GCDFP-15), in 72 primary breast tumours. AR immunoreactivity was present in the nuclei of breast tumour cells and was correlated with oestrogen receptor (ER; P < 0.05) and progesterone receptor (PR; P < 0.01) status. PSA and GCDFP-15 immunoreactivity was present in the cytoplasm of tumour cells but not the adjacent stromal cells. AR-positive cells were present in 85% (61/72) of breast tumours, and 98% (43/44) of PSA-positive and 92% (44/48) of GCDFP-15-positive tumours were also positive for AR. Positive immunoreactivity for both PSA and GCDFP-15 in breast tumours was highly dependent on AR status (odds ratios of 24.0 and 4.5 respectively), but unrelated to age, ER and PR status and axillary lymph node involvement. PSA immunoreactivity was more frequently observed in moderate and well-differentiated tumours and was significantly (P < 0.001) associated with GCDFP-15 immunoreactivity. In conclusion, PSA and GCDFP-15 immunoreactivity was dependent on the presence of AR, but not ER or PR in primary breast tumours.     

Relationship of PS2 with response to tamoxifen therapy in patients with recurrent breast cancer.

PS2, an oestrogen-inducible protein, was measured in the cytosol of 230 primary tumours from patients who were subjected to first-line tamoxifen therapy for advanced disease without prior adjuvant therapy with tamoxifen. PS2 correlated positively with oestrogen receptor (ER, P < 0.01) and progesterone receptor content (PgR, P < 0.001), and with the length of progression-free survival (PFS, P = 0.05). Although not statistically significant, higher levels of PS2 (> or = 10 ng mg-1 protein) were also associated with increased probability of response to tamoxifen treatment and a longer total post-relapse survival (PRS). ER, PgR, menopausal status, site of disease and prior adjuvant chemotherapy were all associated with response to tamoxifen therapy and with PFS. In multivariate analysis for PFS, low levels of ER and PgR, visceral metastasis, a disease-free interval of less than 1 year and prior adjuvant chemotherapy were all significantly associated with an increased probability of a rapid disease progression after start of tamoxifen therapy. In the subset of 83 tumours with intermediate levels of ER and PgR (both > or = 10, but not both > or = 75 fmol mg-1 protein), PS2 was positively related with the length of PFS (P < 0.01) and PRS (P < 0.05). PS2 remained the strongest factor in multivariate analysis for PFS (P < 0.01) in this ER/PgR intermediate subgroup, but was not of predictive value in univariate or multivariate analysis for both PFS and PRS in tumours classified as ER/PgR low or high (> or = 75 fmol mg-1 protein). It is concluded that PS2 status may be used as a parameter, additional to ER and PgR, for better refinement of prediction of response to tamoxifen treatment in advanced breast cancer patients especially with intermediate ER/PgR levels in their primary tumour.     

The prognostic significance of expression of the multidrug resistance-associated protein (MRP) in primary breast cancer.

In the present study, we determined the frequency and intensity of MRP protein expression by monoclonal antibody immunohistochemistry in a series of 259 resected invasive primary breast carcinomas, and we evaluated MRP immunoreactivity in relation to patient and tumour characteristics, relapse-free (RFS) and overall survival (OS). The immunostaining was graded on a semiquantitative scale that ranged from (-) to ( ). Overall, 34% of the tumours were positive for anti-MRP antibody: 19% showed weak cytoplasmic staining (+), 14% had clear cytoplasmic staining (++) and only 1% of the tumours had a strong cytoplasmic as well as membranous staining ( ). MRP expression was not related to patient''s age, menopausal status, tumour size, differentiation grade, oestrogen and progesterone receptor level or lymph node involvement. In an exploratory univariate analysis of all patients, only primary tumour size and number of lymph nodes involved were significantly associated with shortened RFS (P < 0.001 and P < 0.001 respectively) and OS (P = 0.02 and P < 0.001 respectively). In Cox univariate analysis for RFS in subgroups of patients stratified by menopausal status, tumour size, nodal status, adjuvant systemic therapy and oestrogen and progesterone receptor status, MRP expression was associated with increased risk for failure in patients with small tumours (T1), in node-negative patients and in node-positive patients who received adjuvant systemic chemotherapy with cyclophosphamide, methotrexate and 5-fluorouracil (CMF); the relative hazard rate (RHR) for relapse was increased in the presence of MRP, with RHR values with 95% confidence limits (CL) of 2.8 (1.2-6.9), 2.1 (1.0-4.2) and 2.8 (0.8-9.9) respectively. In analysis for OS, expression of MRP was also associated with increased risk for failure in patients with small tumours (T1) [RHR (95% CL) 2.3 (0.9-6.0)] and in node-positive patients who received adjuvant systemic chemotherapy with CMF [RHR (95% CL) 3.7 (0.8-17.1)] but not in node-negative patients [RHR (95% CL) 1.1 (0.4-2.6)]. In conclusion, our results show that MRP is frequently overexpressed in primary breast cancer and suggest that MRP expression might be of prognostic significance in the subgroups of patients with the more favourable prognosis, i.e. patients with small tumours and node-negative patients, as well as in the setting of adjuvant systemic chemotherapy. In primary breast cancer, MRP might be related to altered cell biological behaviour, including a more aggressive phenotype, and resistance to adjuvant systemic chemotherapy.     

Cyclin D1 overexpression related to retinoblastoma protein expression as a prognostic marker in human oesophageal squamous cell carcinoma.

The relationship between aberrant expression of cyclin D1 and retinoblastoma (RB) protein and clinicopathological factors was investigated in 80 patients with oesophageal SCC using immunohistochemical analyses. Heterogeneous staining of cancer cell nuclei with antibody to cyclin D1 was found in 31.3% of patients (25 out of 80 patients). Nuclear staining of cancer cells with anti-RB antibody was homogeneous in 10.0% (8 out of 80 patients) and heterogeneous in 58.8% (47 out of 80 patients). Among cases with homogeneous staining for RB protein, 75% (six out of eight patients) exhibited simultaneous positivity for cyclin D1 (P < 0.05). No significant relationship was found between cyclin D1 or RB protein expression and various clinicopathological parameters. The prognosis of patients with cyclin D1-positive tumours was significantly poorer than that of the other patients (P < 0.01). In addition, when patients with cyclin D1-positive and -negative tumours were stratified according to presence or absence of lymph node metastasis and RB status, the cumulative survival rates in the cyclin D1-positive groups were significantly lower for patients without lymph node metastasis (P < 0.01) and for patients whose tumours were positive for RB (P< 0.0001). These findings suggest the possibility that cyclin D1 positivity is a useful prognostic marker related to lymph node metastasis and RB protein expression in human oesophageal SCC, in addition to clinicopathological factors.     

Metallothionein expression in human breast cancer.

Metallothioneins are ubiquitous low molecular weight proteins characterised by high cysteine content and affinity for binding heavy metals. Abnormal metallothionein function and expression have been implicated in various disease states, including neoplasia. The aim of this study was to investigate metallothionein expression in human breast carcinoma. Sections of routinely fixed and processed blocks of tumour from 100 consecutive cases of primary operable breast carcinoma were stained for metallothionein using a recently developed monoclonal antibody and a standard immunohistochemical technique. Expression was scored on the basis of microscopical assessment of percentage of tumour cells staining. One patient was lost to follow-up and excluded from the study. A significant association (P < 0.0001) was observed between metallothionein expression and tumour type, with low levels being observed in tumours of good prognostic type. There was also a significant association with local recurrence (P < 0.02) and a significant difference (P < 0.02) in both survival and disease-free interval between tumours showing low and high levels of expression, the latter indicating a poor prognosis. No relationship was observed with patient age, tumour size, lymph node stage, histological grade, vascular invasion, menopausal status or oestrogen receptor status. The assessment of metallothionein expression in human breast cancer appears to provide prognostic information and may have important implications for understanding its development.     

Prognostic value of bcl-2 expression in invasive breast cancer.

Expression of the bcl-2 proto-oncogene was studied immunohistochemically in 251 invasive ductal breast carcinomas (median follow-up time 91 months, range 24-186 months) and the results were correlated with clinicopathological data and prognostic variables. Sixty-three (25%) tumours were scored bcl-2 negative and 188 (75%) tumours were bcl-2 positive. No relationship could be observed between bcl-2 status and tumour grade, pTNM staging or menopausal status. A strong positive relationship was demonstrated between bcl-2 immunoreactivity and oestrogen receptor status (P < 0.001) and progesterone receptor status (P < 0.001). No prognostic value was demonstrated for bcl-2 expression on disease-free survival and overall survival in axillary node-negative breast cancer patients. However, in axillary node-positive breast cancer patients multivariate analysis demonstrated absence of bcl-2 expression to be independently related to shortened disease-free survival (P = 0.003) and shortened overall survival (P < 0.001). Our results suggest a potential important role for bcl-2 expression as a modulator of response to adjuvant therapy in breast cancer.     

Procoagulant activity may be a marker of the malignant phenotype in experimental prostate cancer.

Using a one-stage kinetic chromogenic assay, we studied the procoagulant activity (PCA) of prostatic tissue in an experimental model of prostate cancer in the rat. PCA was present in homogenates of rat prostate glands containing either benign or malignant tumours. The procoagulant activated factor X directly and was provisionally characterised as a tissue factor-factor VIIa complex. There was no significant differences in PCA between control rats and rats exposed to carcinogens that did not develop tumour. Levels in rats that developed tumours were significantly higher (P < 0.01) than all other groups and there was a positive correlation between tumour weight and PCA (r = 0.85, P < 0.001). Furthermore, prostatic PCA levels were higher in the metastasis (P < 0.02). We conclude that PCA reflects the malignant phenotype in this animals, the PCA of the primary tumour was compared with that of the corresponding secondary deposit and levels were higher in the metastasis (P < 0.02). We conclude that PCA reflects the malignant phenotype in this model of experimental prostate cancer and suggest that this parameter is worth evaluating as a potential tumour marker in the human disease.     

Prognostic significance of cyclin E and p53 protein overexpression in carcinoma of the renal pelvis and ureter.

Cyclin E gene alteration in the cell cycle plays an important role in carcinogenesis, while p53 protein affects different phase checkpoint pathways by activating p21WAF1/CIP1 in the normal cell cycle. We immunohistochemically examined the expression of cyclin E and p53 proteins in 121 patients with transitional cell carcinoma (TCC) of the renal pelvis and ureter to determine their significance for tumour behaviour and patient prognosis. Cyclin E and p53 immunostaining of the nucleus was observed in 36 tumours (29.8%) and 35 tumours (28.9%) respectively. A significant percentage, 69.4% (25 out of 36 tumours), of the cyclin E-positive tumours exhibited simultaneous labelling for p53 (P < 0.05). Mirror-section technique was performed in five selected double-positive tumours to identify cancer cells that were nuclei positive for both cyclin E and p53. The prevalence of cases simultaneously exhibiting both cyclin E and p53 immunostaining was higher in the high-grade tumours (P < 0.01) than in the other types of tumours. Patients with TCCs coexpressing cyclin E and p53 had a significantly poorer prognosis than those expressing neither cyclin E nor p53 (P < 0.001). These in vivo findings provide evidence for cyclin E protein overexpression in TCCs intimately associated with p53 alteration and suggest that simultaneous overexpression of both cyclin E and p53 is related to tumour behaviour and poor prognosis.     

C-erbB-3 in human breast carcinoma: expression and relation to prognosis and established prognostic indicators.

A series of 346 patients with primary operable breast cancer and a series of 145 patients with advanced breast cancer were investigated for c-erbB-3 protein expression using the monoclonal antibody RTJ1. Formalin-fixed, paraffin-embedded tumour samples were stained using a standard immunochemical method and staining was assessed on a four-point scale. The study aimed to observe the expression of the c-erbB-3 protein and investigate any relationship between expression and established prognostic indicators and prognosis. In both the primary and advanced series breast tumour tissue was found to stain heterogeneously for c-erbB-3. The staining was observed to be predominantly cytoplasmic and the majority of tumours exhibited moderate positivity. However, 15% and 35% of cases in the primary operable and advanced series respectively displayed strong positive staining. No significant difference was found between the staining in the primary and advanced series. In the primary operable breast cancers, no significant associations were demonstrated with overall survival, disease-free interval, regional recurrence, the presence of distant metastases, age, menopausal status, oestrogen receptor status, histological grade, lymph node stage, vascular invasion and c-erbB-2 protein expression. However, a significant association was seen between the degree of c-erbB-3 immunoreactivity and both tumour size (P < 0.01) and tumour type prognostic group (P = 0.05). No overall association with local recurrence was seen when the four groups of c-erbB-3 expression were analysed (P = 0.12), but when those tumours showing no or weak staining were compared with those showing moderate and strong immunoreactivity it was seen that the latter were significantly more likely to develop local recurrence (P = 0.03). In the series of patients with advanced disease, no significant associations were demonstrated with survival, UICC criteria, age, menopausal status, oestrogen receptor status, histological grade, c-erbB-2 status or the presence of vascular invasion. In conclusion this study found variable expression of c-erbB-3 protein in human breast carcinoma and an association with some recognised prognostic factors in those patients with primary operable breast carcinoma. It seems, however, unlikely that c-erbB-3 protein expression will emerge as a powerful enough prognostic factor to be of value in clinical practice.     

Changes in tumour blood flow, oxygenation and interstitial fluid pressure induced by pentoxifylline.

Pentoxifylline (PTX) has been shown to increase radiation damage to tumours and to decrease late radiation-induced injury to normal tissues. This tumour radiation sensitisation results from increased oxygen supply via improved tumour perfusion. We propose that the improved perfusion results from decreased viscous resistance and/or geometric resistance. The decreased flow resistance may be accompanied by a reduction in microvascular pressure (MVP). Since MVP is approximately equal to the interstitial fluid pressure (IFP), PTX should lead to a decrease in IFP. To test this hypothesis, we measured PO2, laser Doppler flow (RBC flux) and IFP in FSaII murine tumours at two doses (PTX at 25 and 100 mg per kg body weight) which sensitise this tumour to X-irradiation. We found that 25 mg kg-1 PTX was ineffective, but 100 mg kg-1 PTX was effective in increasing the PO2 of this tumour. PTX at 100 mg kg-1 (i.p.) increased median PO2 from 5 to 7 mmHg (P < 0.05) within 2 h, and decreased the fraction of PO2 values < 5 mmHg from 65% to 45% (P < 0.05). In support of our hypothesis, we found that with this dose of PTX, RBC flux in the tumour centre increased significantly (n = 6, P < 0.05) prior to an approximately 40% decrease (n = 13, P < 0.05) in tumour interstitial fluid pressure (TIFP), without changes in mean arterial blood pressure (MABP). In conclusion, a single i.p. administration of PTX at 100 mg kg-1 can increase oxygen availability in the tumour due to ameliorate hypoxia in tumour microregions. Second, PTX can lower the elevated TIFP without lowering the MABP.     

Effect of endogenous and exogenous EGF on the growth of EGF receptor-hyperproducing human squamous cell carcinoma implanted in nude mice.

The effect of epidermal growth factor (EGF) on the biological behaviour of human tumours in vivo is still controversial. We investigated the effect of EGF on the growth of an EGF receptor-hyperproducing human epidermoid carcinoma, A431 tumour, and on a human small-cell lung carcinoma, H69 tumour, without detectable EGF receptor by using sialoadenectomised (sialex) mice as an endogenous EGF-suppressed animal model. The plasma EGF concentration in the sialex athymic mice was significantly lower than that in the sham-operated mice (P < 0.05). After exogenous EGF replacement with an implanted minipump, the plasma EGF concentration was significantly increased in both groups (P < 0.05). There was no significant difference between the body weight growth curves of sialex and sham-operated mice with and without EGF treatment. The tumour weight of A431, both estimated and measured in sialex mice, was significantly lower than that in sham-operated control mice (P < 0.05), and the growth of A431 tumour was significantly increased by exogenous EGF treatment (P < 0.05). Mitotic activity of these tumours detected by immunohistochemical staining for incorporated bromodeoxyuridine indicated a mitosis-stimulatory effect of endogenous and exogenous EGF on A431 tumours. In contrast to these findings on A431 tumours, a growth-stimulatory effect of endogenous and exogenous EGF was not observed in the H69 tumour. These results suggest a growth-promoting effect of physiological levels of endogenous EGF on EGF receptor-hyperproducing human tumours in vivo.