Pathology parameters and adjuvant tamoxifen response in a randomised premenopausal breast cancer trial

BACKGROUND

Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment.

AIMS

To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer.

MATERIALS/METHODS

Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression.

RESULTS

Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly.

CONCLUSIONS

Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.

Requirement for CDK4 kinase function in breast cancer

Cyclin D1 is overexpressed in the majority of human breast cancers. We previously found that mice lacking cyclin D1 are resistant to mammary carcinomas triggered by the ErbB-2 oncogene. In this study, we investigated which function of cyclin D1 is required for ErbB-2-driven mammary oncogenesis. We report that the ability of cyclin D1 to activate cyclin-dependent kinase CDK4 underlies the critical role for cyclin D1 in breast cancer formation. We also found that the continued presence of CDK4-associated kinase activity is required to maintain breast tumorigenesis. We analyzed primary human breast cancers and found high cyclin D1 levels in a subset (approximately 25%) of ErbB-2-overexpressing tumors. We propose that this subset of breast cancer patients might benefit from inhibiting CDK4 kinase.

Adverse effect of adjuvant tamoxifen in premenopausal breast cancer with cyclin D1 gene amplification

Cyclins D1 and A2 are cell cycle regulators that also have the ability to interact with the estrogen receptor (ER) and consequently interfere with antiestrogen treatment in breast cancer. Experimental data support this concept, but the clinical relevance needs to be further established. In this study, we evaluated cyclin D1 and A2 protein expression by immunohistochemistry and cyclin D1 gene (CCND1) amplification by fluorescence in situ hybridization in 500 primary breast cancers arranged in tissue microarrays. Patients had been randomized to 2 years of adjuvant tamoxifen or no treatment with a median follow-up of 14 years, allowing for subgroup analysis of treatment response defined by cyclin status. We found that both cyclin D1 and A2 protein overexpression was associated with an impaired tamoxifen response, although not significant in multivariate interaction analyses, whereas tamoxifen-treated patients with CCND1-amplified tumors had a substantially increased risk for disease recurrence after tamoxifen treatment in univariate analyses [relative risk (RR), 2.22; 95% confidence interval (95% CI), 0.94-5.26; P = 0.06] in contrast to non-amplified tumors (RR, 0.39; 95% CI, 0.23-0.65; P < 0.0001). Consequently, a highly significant interaction between tamoxifen treatment and CCND1 amplification could be shown regarding both recurrence-free survival (RR, 6.38; 95% CI, 2.29-17.78; P < 0.001) and overall survival (RR, 5.34; 95% CI, 1.84-15.51; P = 0.002), suggesting an agonistic effect of tamoxifen in ER-positive tumors. In node-positive patients, the disparate outcome according to gene amplification status was even more accentuated. In summary, our data implicate that despite a significant correlation to cyclin D1 protein expression, amplification status of the CCND1 gene seems a strong independent predictor of tamoxifen response, and possibly agonism, in premenopausal breast cancer.

Exploring cancer register data to find risk factors for recurrence of breast cancer--application of Canonical Correlation Analysis

Background

A common approach in exploring register data is to find relationships between outcomes and predictors by using multiple regression analysis (MRA). If there is more than one outcome variable, the analysis must then be repeated, and the results combined in some arbitrary fashion. In contrast, Canonical Correlation Analysis (CCA) has the ability to analyze multiple outcomes at the same time.

One essential outcome after breast cancer treatment is recurrence of the disease. It is important to understand the relationship between different predictors and recurrence, including the time interval until recurrence. This study describes the application of CCA to find important predictors for two different outcomes for breast cancer patients, loco-regional recurrence and occurrence of distant metastasis and to decrease the number of variables in the sets of predictors and outcomes without decreasing the predictive strength of the model.

Methods

Data for 637 malignant breast cancer patients admitted in the south-east region of Sweden were analyzed. By using CCA and looking at the structure coefficients (loadings), relationships between tumor specifications and the two outcomes during different time intervals were analyzed and a correlation model was built.

Results

The analysis successfully detected known predictors for breast cancer recurrence during the first two years and distant metastasis 2–4 years after diagnosis. Nottingham Histologic Grading (NHG) was the most important predictor, while age of the patient at the time of diagnosis was not an important predictor.

Conclusion

In cancer registers with high dimensionality, CCA can be used for identifying the importance of risk factors for breast cancer recurrence. This technique can result in a model ready for further processing by data mining methods through reducing the number of variables to important ones.

Tumor-specific expression of vascular endothelial growth factor receptor 2 but not vascular endothelial growth factor or human epidermal growth factor receptor 2 is associated with impaired response to adjuvant tamoxifen in premenopausal breast cancer

PURPOSE

Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) are often coexpressed in breast cancer, and potentially affect cellular pathways and key proteins such as the estrogen receptor (ER) targeted by endocrine treatment. We therefore explored the association between adjuvant tamoxifen treatment in breast cancer and expression of VEGF-A and VEGFR2, as well as human epidermal growth factor receptor 2 (HER2), which represents a candidate gene product involved in tamoxifen resistance.

PATIENTS AND METHODS

Immunohistochemical expression of tumor-specific VEGF-A, VEGFR2, and HER2 was evaluated in tumor specimens from premenopausal breast cancer patients randomly assigned to 2 years of tamoxifen or no treatment (n = 564), with 14 years of follow-up. Hormone receptor status was determined in 96% of the tumors.

RESULTS

VEGF-A, VEGFR2, and HER2 were assessable in 460, 472, and 428 of the tumors, respectively. In patients with ER-positive and VEGFR2-low tumors, adjuvant tamoxifen significantly increased recurrence-free survival (RFS; [HR] hazard ratio for RFS, 0.53; P = .001). In contrast, tamoxifen treatment had no effect in patients with VEGFR2-high tumors (HR for RFS, 2.44; P = .2). When multivariate interaction analyses were used, this difference in treatment efficacy relative to VEGFR2 expression status was statistically significant for both ER-positive (P = .04) plus ER-positive and progesterone receptor-positive tumors. We found no significant difference in tamoxifen treatment effects in relation to VEGF-A or HER2 status.

CONCLUSION

Tumor-specific expression of VEGFR2 was associated with an impaired tamoxifen effect in hormone receptor-positive premenopausal breast cancer. Tamoxifen in combination with VEGFR2 inhibitors might be a novel treatment approach for VEGFR2-expressing breast cancer, and such a treatment might restore the tamoxifen response.

Role of cyclin D1 in ErbB2-positive breast cancer and tamoxifen resistance

Cyclin D1 plays an important role in the regulation of the G1 phase in the cell cycle. In mammary epithelial cells the expression of cyclin D1 is regulated through the oestrogen receptor and via ErbB2 signalling. Here we investigated the prognostic significance of cyclin D1 among 230 breast cancer patients randomised for tamoxifen, CMF chemotherapy and radiotherapy. The importance of combined cyclin D1 and ErbB2 overexpression was also analysed. Immunohistochemical analysis of the cyclin D1 expression resulted in 69 (29.8%) weakly positive, 107 (46.5%) moderately positive and 54 (23.7%) strongly positive cases. The prognostic importance of ErbB2 was significantly greater for patients whose tumours overexpressed cyclin D1 than for other patients (p = 0.026). In the former group, ErbB2 overexpression was strongly associated with increased risk of recurrence (RR = 4.7; 95% CI, 2.1-10.4) and breast cancer death (RR = 5.4; 95% CI, 2.3-12.6). This result is in accordance with experimental studies demonstrating a link between cyclin D1 and ErbB2 in oncogenesis. Among oestrogen receptor positive patients, those with moderate cyclin D1 expression significantly did benefit from tamoxifen treatment (RR = 0.42; 95% CI, 0.21-0.82) whereas those with weak or strong expression did not. Therefore cyclin D1 might be a predictive marker for tamoxifen resistance.

Sulfotransferase1A1 and risk of postmenopausal breast cancer

The detoxification enzyme sulfotransferase1A1 (SULT1A1) is implicated in the inactivation of estrogens and the activation of promutagens and procarcinogens. SULT1A1 activity varies among individuals, and this difference in phenotype is, in part, controlled by genetic polymorphism (Arg-->His in codon 213). It is hypothesized that the His allele contributes to the risk of postmenopausal breast cancer. Frequencies of the Arg/His alleles were estimated in 229 postmenopausal breast cancer patients and 227 age-matched controls using a PCR-RFLP assay. Allele frequencies and genotype distributions were not statistically different between postmenopausal breast cancer patients and the population-based controls, i.e. neither of the alleles is associated with an increased risk of breast cancer in the present study.

17beta-Hydroxysteroid dehydrogenases involved in local oestrogen synthesis have prognostic significance in breast cancer

The 17β-hydroxysteroid dehydrogenase (17HSD) enzymes are involved in the local regulation of sex steroids. The 17HSD type 1 enzyme catalyses the interconversion of the weak oestrone (E1) to the more potent oestradiol (E2), whereas 17HSD type 2 catalyses the oxidation of E2 to E1. The aim of this study was to correlate the expression of these enzymes in the tumour with the recurrence-free survival of tamoxifen-treated breast cancer patients. We used real-time reverse transcriptase PCR to investigate the mRNA expression of 17HSD types 1 and 2 in tumour samples from 230 postmenopausal patients. For the patients with oestrogen receptor (ER)-positive breast cancer, we found a statistically significant positive correlation between recurrence-free survival and expression of 17HSD type 2 (P=0.026). We examined the ratio of 17HSD types 2 and 1, and ER-positive patients with low ratios showed a significantly higher rate of recurrence than those with higher ratios (P=0.0047). ER positive patients with high expression levels of 17HSD type 1 had a significantly higher risk for late relapse (P=0.0051). The expression of 17HSD types 1 and 2 in breast cancer differs from the expression of these enzymes in normal mammary gland, and this study indicates that the expression has prognostic significance in breast cancer.

Two years of adjuvant tamoxifen in premenopausal patients with breast cancer: a randomised, controlled trial with long-term follow-up

Adjuvant tamoxifen treatment increases recurrence-free survival (RFS) and overall survival (OS) in early breast cancer, although in premenopausal patients the number of studies comparing tamoxifen vs no treatment are limited. We report herein the effect on RFS of adjuvant tamoxifen treatment in a multicentre trial of premenopausal patients with stage II breast cancer patients randomised between 1986 and 1991 to 2 years of tamoxifen treatment (n=276) or no treatment (n=288). The receptor status of the tumour was known for 541 (96%) of the patients included. Tamoxifen treatment significantly increased RFS in patients with hormone receptor-positive (oestrogen receptor-positive (ER+) and/or progesterone receptor-positive (PR+)) tumours (Relative Risk (RR) 0.65; 95% Confidence Interval (CI): 0.48-0.89, P=0.006), and the beneficial effect of tamoxifen was extended to patients with indicators of poor prognosis, such as young age and nodal-positivity. PR status was a significant predictor of response to tamoxifen in multivariate models with testing of interactions of hormone receptor status and adjuvant therapy.

Genotype of metabolic enzymes and the benefit of tamoxifen in postmenopausal breast cancer patients

Background

Tamoxifen is widely used as endocrine therapy for oestrogen-receptor-positive breast cancer. However, many of these patients experience recurrence despite tamoxifen therapy by incompletely understood mechanisms. In the present report we propose that tamoxifen resistance may be due to differences in activity of metabolic enzymes as a result of genetic polymorphism. Cytochrome P450 2D6 (CYP2D6) and sulfotransferase 1A1 (SULT1A1) are polymorphic and are involved in the metabolism of tamoxifen. The CYP2D6*4 and SULT1A1*2 genotypes result in decreased enzyme activity. We therefore investigated the genotypes of CYP2D6 and SULT1A1 in 226 breast cancer patients participating in a trial of adjuvant tamoxifen treatment in order to validate the benefit from the therapy.

Methods

The patients were genotyped using PCR followed by cleavage with restriction enzymes.

Results

Carriers of the CYP2D6*4 allele demonstrated a decreased risk of recurrence when treated with tamoxifen (relative risk = 0.28, 95% confidence interval = 0.11–0.74, P = 0.0089). A similar pattern was seen among the SULT1A1*1 homozygotes (relative risk = 0.48, 95% confidence interval = 0.21–1.12, P = 0.074). The combination of CYP2D6*4 and/or SULT1A1*1/*1 genotypes comprised 60% of the patients and showed a 62% decreased risk of distant recurrence with tamoxifen (relative risk = 0.38, 95% confidence interval = 0.19–0.74, P = 0.0041).

Conclusion

The present study suggests that genotype of metabolic enzymes might be useful as a guide for adjuvant endocrine treatment of postmenopausal breast cancer patients. However, results are in contradiction to prior hypotheses and the present sample size is relatively small. Findings therefore need to be confirmed in a larger cohort.

Activation of the phosphatidylinositol 3-kinase/Akt pathway prevents radiation-induced apoptosis in breast cancer cells

Radiotherapy is widely used in the treatment of breast cancer and reduces the risk of loco-regional recurrence. Overexpression of the erbB2 receptor occurs in 20-30% of all breast cancers, and seems to be involved in chemotherapeutic resistance of breast cancer cells and radioresistance of lung cancer cells. The hypothesis of this study was that erbB2 confers resistance to radiation-induced apoptosis in breast cancer cells through the phosphatidylinositol 3-kinase (PI3-K)/Akt signalling pathway. Two human breast cancer cell lines were used, BT-474 and MCF-7. BT-474 cells overexpress erbB2 and have mutated p53, while MCF-7 have normal expression of erbB2 and functional p53. The cells were treated with the PI3-K inhibitor wortmannin or the erbB receptor ligand heregulin-beta1, which is expressed by both malignant and stromal cells in vivo. After pharmacological treatment, the cells were irradiated with 10 Gy gamma-radiation. Consistent with the p53 status in the cell lines, gamma-radiation caused G1 arrest in MCF-7 cells, but not in BT-474 cells. 10 Gy gamma-radiation increased apoptosis by on an average 76% (95% CI, 44-109%) in MCF-7. Treatment of MCF-7 with heregulin-beta1 decreased apoptosis by 66% (95% CI, 48-84%) compared to the untreated controls. In BT-474 cells, wortmannin in combination with radiation resulted in 119% (95% CI, 76-161%) more apoptosis compared to wortmannin alone, whereas radiation alone resulted in 45% (95% CI, 15-75%) increased apoptosis. This radiosensitising effect was not seen in MCF-7. Furthermore, transfection of MCF-7 cells with constitutively active Akt made the cells more resistant against apoptosis. Taken together, our results support the hypothesis that the erbB2/PI3-K/Akt signalling pathway is involved in resistance to radiation-induced apoptosis in breast cancer cells in which this signalling pathway is overstimulated.

Improved DNA flow cytometric, DNA ploidy, and S-phase reproducibility between 15 laboratories in analysis of breast cancer using generalized guidelines

BACKGROUND

Lack of generalized guidelines for DNA flow cytometric analysis (FCM) may be the main reason for its limited use in the clinical management of breast cancer.

METHODS

After an initial interlaboratory reproducibility study (Round I), we concluded that it was the evaluation of the DNA histograms rather than the technical performance of the analysis that was the main reason for discordant results between laboratories. Guidelines for the interpretation of DNA histograms were therefore drawn up. We present here data from a new reproducibility study (Round II) using these guidelines.

RESULTS

For 10 laboratories also participating in Round I, use of the guidelines increased the concordance in DNA ploidy status from 89% to 100% for the 46 samples used in both rounds. The concordance rate for SPF also increased; mean r(s)-value increased from 0.81 to 0.88, and mean kappa value (lower two-thirds versus upper third versus not reported) increased from 0.55 to 0.71. Five new laboratories, participating only in Round II, also agreed with the 10 original laboratories regarding DNA ploidy status. With the inclusion of all 15 laboratories, we obtained a mean r(s)-value of 0.81 and a mean kappa value of 0.72 for SPF.

CONCLUSIONS

Generalized guidelines for DNA FCM increase interlaboratory agreement, which is highly important in clinical routines and in multicenter studies. Furthermore, inexperienced FCM laboratories using generalized guidelines can produce and interpret DNA FCM data equally as well as experienced laboratories.

Amplification of HSD17B1 and ERBB2 in primary breast cancer

Estrogens play a crucial role in the development of breast cancer. Estradiol can be produced in the breast tissue in situ, and one of the enzymes involved in this process is 17beta-hydroxysteriod dehydrogenase (17beta-HSD) type 1 that catalyzes the interconversion of estrone (E1) to the biologically more potent estradiol (E2). The gene coding for 17beta-HSD type 1 (HSD17B1) is located at 17q12-21, close to the more studied ERBB2 and BRCA1. The aim of this study was to investigate if HSD17B1 shows an altered gene copy number in breast cancer. We used real-time PCR and examined 221 postmenopausal breast tumors for amplification of HSD17B1 and ERBB2. In all, 32 tumors (14.5%) showed amplification of HSD17B1 and 21% were amplified for ERBB2. Amplification of the two genes was correlated (P=0.00078) and in 14 tumors (44%) with amplification of HSD17B1, ERBB2 was co amplified. The patients with amplification in at least one of the genes had a significantly worse outcome than patients without (P=0.0059). For estrogen receptor (ER)-positive patients who received adjuvant tamoxifen, amplification of HSD17B1 was related to decreased breast cancer survival (P=0.017), whereas amplification of ERRB2 was not. Amplification of HSD17B1 might be an indicator of adverse prognosis among ER-positive patients, and possibly a mechanism for decreased benefit from tamoxifen treatment.

Akt kinases in breast cancer and the results of adjuvant therapy

BACKGROUND

The serine/threonine kinase Akt, or protein kinase B, has recently been a focus of interest because of its activity to inhibit apoptosis. It mediates cell survival by acting as a transducer of signals from growth factor receptors that activate phosphatidylinositol 3-kinase.

METHODS

We analysed the expression of the isoforms Akt1 and Akt2 as well as phosphorylated Akt (pAkt) by immunohistochemistry in frozen tumour samples from 280 postmenopausal patients who participated in a randomised trial comparing cyclophosphamide-methotrexate-5-fluorouracil chemotherapy and postoperative radiotherapy. The patients were simultaneously randomised to tamoxifen or to no endocrine treatment.

RESULTS

Marked staining was found in 24% of the tumours for Akt1, but in only 4% for Akt2. A low frequency of Akt2-positive cells (1-10%) was observed in another 26% of the tumours. pAkt was significantly associated with both Akt1 and Akt2 expression. Overexpression of erbB2 correlated significantly with pAkt (P = 0.0028). The benefit from tamoxifen was analysed in oestrogen receptor (ER)-positive patients. Patients with a negative status of Akt (no overexpression of Akt1, Akt2 or pAkt) showed significant benefit from tamoxifen. The relative rate of distant recurrence, with versus without tamoxifen, was 0.44 (95% confidence interval [CI], 0.25-0.79) for ER+/Akt1- patients, while it was 0.72 (95% CI, 0.34-1.53) for ER+/Akt1+ patients. The difference in rate ratio did not reach statistical significance. The rate of locoregional recurrence was significantly decreased with radiotherapy versus chemotherapy for Akt-negative patients (rate ratio, 0.23; 95% CI, 0.08-0.67; P = 0.0074), while no benefit was evident for the Akt-positive subgroup (rate ratio, 0.77; 95% CI, 0.31-1.9; P = 0.58). The interaction between Akt and the efficacy of radiotherapy was significant in multivariate analysis (P = 0.042).

CONCLUSION

Activation of the Akt pathway is correlated with erbB2 overexpression in breast cancer. The results suggest that Akt may predict the local control benefit from radiotherapy.

Activation of AKT/PKB in breast cancer predicts a worse outcome among endocrine treated patients

Akt/PKB is a serine/threonine protein kinase that regulates cell cycle progression, apoptosis and growth factor mediated cell survival in association with tyrosine kinase receptors. The protein is a downstream effector of erbB-2 with implications in breast cancer progression and drug resistance in vitro. We aimed to examine the role of Akt-1 in breast cancer patients, by determining whether the expression (Akt-1) and/or activation (pAkt) were related to prognostic markers and survival. The expression of erbB-2, heregulin beta 1 and Bcl-2 was also assessed by flow cytometry or immunohistochemistry. This study comprised 93 patients, aged <50 who were treated with tamoxifen and/or goserelin. We found that pAkt was associated with lower S-phase fraction (P=0.001) and the presence of heregulin beta 1-expressing stromal cells (P=0.017). Neither Akt-1 nor pAkt was related with other factors. Tumour cells-derived heregulin beta 1 was found mainly in oestrogen receptor negative (P=0.026) and node negative (P=0.005) cases. Survival analysis revealed that pAkt positive patients were more prone to relapse with distant metastasis, independently of S-phase fraction and nodal status (multivariate analysis; P=0.004). The results suggest that activation of Akt may have prognostic relevance in breast cancer.

DNA and cell cycle analysis as prognostic indicators in breast tumors revisited

Both DNA ploidy and S-phase ploidy are promising prognostic factors for node-negative breast cancer patients. Based largely on the analysis of one large study, much of the reported problems with these factors have been caused by some unappreciated complexities in categorizing DNA ploidy into low- and high-risk groups and the lack of some necessary adjustments to eliminate unwanted correlations between DNA S-phase and ploidy. When both DNA ploidy and S-phase are compensated properly, they become independent prognostic markers, forming a powerful prognostic model.

Abnormal expression of 17beta-hydroxysteroid dehydrogenases in breast cancer predicts late recurrence

The 17beta-hydroxysteroid dehydrogenase (17beta-HSD) enzymes are involved in the interconversion of biologically active and inactive sex steroids and are considered to play a critical role in the in situ metabolism of estrogen, especially in estrogen-dependent breast cancer. The gene encoding 17beta-HSD type 2 is located at 16q24.1-2, and earlier studies have shown that allelic loss in this region is an early and frequent event in breast cancer progression. Recurrence of hormone-dependent breast cancer frequently occurs several years after the primary treatment. The aim of this study was to investigate whether the expression of 17beta-HSD types 1 and 2 differs in tumors from patients with late relapses (>5 years) compared with controls without recurrence after long-term follow-up. Using real-time reverse transcription-PCR, we found that the normal mammary gland expressed both 17beta-HSD types 1 and 2, whereas the tumors frequently lacked detectable levels of type 2. Only 10% of the estrogen receptor-positive tumors expressed type 2, whereas 31% of the ER-negative tumors did so (P = 0.031). In a case-control series of 84 patients, a high level of 17beta-HSD type 1 indicated increased risk to develop late relapse of breast cancer (odds ratio, 3.0; 95% confidence interval, 1.0-12.6; P = 0.041), whereas retained expression of type 2 indicated decreased risk (odds ratio, 0.25; 95% confidence interval, 0.05-1.2; P = 0.050). In multivariate analysis of the estrogen receptor-positive patients, the absence of 17beta-HSD type 2 combined with a high expression of type 1 showed prognostic significance (P = 0.016) in addition to DNA aneuploidy (P = 0.0058), whereas progesterone receptor status did not (P = 0.71). These findings suggest that abnormal expression of 17beta-HSD isoforms has prognostic significance in breast cancer and that altered expression of these enzymes may have importance in breast cancer progression.

Decreased tumor cell proliferation as an indicator of the effect of preoperative radiotherapy of rectal cancer

BACKGROUND

Rectal cancer is a common malignancy, with significant local recurrence and death rates. Preoperative radiotherapy and refined surgical technique can improve local control rates and disease-free survival.

PURPOSE

To investigate the relationship between the tumor growth fraction in rectal cancer measured with Ki-67 and the outcome, with and without short-term preoperative radiotherapy.

METHOD

Ki-67 (MIB-1) immunohistochemistry was used to measure tumor cell proliferation in the preoperative biopsy and the surgical specimen.

MATERIALS

Specimens from 152 patients from the Southeast Swedish Health Care region were included in the Swedish rectal cancer trial 1987-1990.

RESULTS

Tumors with low proliferation treated with preoperative radiotherapy had a significantly reduced recurrence rate. The influence on death from rectal cancer was shown only in the univariate analysis. Preoperative radiotherapy of tumors with high proliferation did not significantly improve local control and disease-free survival. The interaction between Ki-67 status and the benefit of radiotherapy was significant for the reduced recurrence rate (p = 0.03), with a trend toward improved disease-free survival (p = 0.08). In the surgery-alone group, Ki-67 staining did not significantly correlate with local recurrence or survival rates.

CONCLUSION

Many Ki-67 stained tumor cells in the preoperative biopsy predicts an increased treatment failure rate after preoperative radiotherapy of rectal cancer.

Optimizing flow cytometric DNA ploidy and S-phase fraction as independent prognostic markers for node-negative breast cancer specimens

Developing a reliable and quantitative assessment of the potential virulence of a malignancy has been a long-standing goal in clinical cytometry. DNA histogram analysis provides valuable information on the cycling activity of a tumor population through S-phase estimates; it also identifies nondiploid populations, a possible indicator of genetic instability and subsequent predisposition to metastasis. Because of conflicting studies in the literature, the clinical relevance of both of these potential prognostic markers has been questioned for the management of breast cancer patients. The purposes of this study are to present a set of 10 adjustments derived from a single large study that optimizes the prognostic strength of both DNA ploidy and S-phase and to test the validity of this approach on two other large multicenter studies. Ten adjustments to both DNA ploidy and S-phase were developed from a single node-negative breast cancer database from Baylor College (n = 961 cases). Seven of the adjustments were used to reclassify histograms into low-risk and high-risk ploidy patterns based on aneuploid fraction and DNA index optimum thresholds resulting in prognostic P values changing from little (P < 0.02) or no significance to P < 0.000005. Other databases from Sweden (n = 210 cases) and France (n = 220 cases) demonstrated similar improvement of DNA ploidy prognostic significance, P < 0.02 to P < 0.0009 and P < 0.12 to P < 0.002, respectively. Three other adjustments were applied to diploid and aneuploid S-phases. These adjustments eliminated a spurious correlation between DNA ploidy and S-phase and enabled them to combine independently into a powerful prognostic model capable of stratifying patients into low, intermediate, and high-risk groups (P < 0.000005). When the Baylor prognostic model was applied to the Sweden and French databases, similar significant patient stratifications were observed (P < 0.0003 and P < 0.00001, respectively). The successful transference of the Baylor prognostic model to other studies suggests that the proposed adjustments may play an important role in standardizing this test and provide valuable prognostic information to those involved in the management of breast cancer patients.

ErbB2 status and the benefit from two or five years of adjuvant tamoxifen in postmenopausal early stage breast cancer

AIM

We aimed to study the importance of erbB2 status in early stage postmenopausal breast cancer for patients who participated in a trial of five vs. two years of adjuvant tamoxifen.

PATIENTS AND METHODS

We analysed the erbB2 status of the tumours from 577 patients participating in the trial, either by a DNA amplification assay (n = 181) or by measurement of the protein level with flow cytometry (n = 396).

RESULTS

ErbB2 was overexpressed or gene amplified in 102 of the patients (18%). Overall, erbB2-positive patients had a significantly lower recurrence-free probability than others, 62% at five years as compared to 83%, and showed a significantly decreased breast cancer survival rate (P = 0.0007). ErbB2 status was significantly associated with recurrence and death in Cox multivariate analysis, adjusting for nodal status, tumour size and estrogen receptor status. The relative risk of recurrence (RR) for five vs. two years of tamoxifen was analysed in relation to erbB2 status for patients still disease-free two years after surgery. Whereas erbB2-negative patients showed significant benefit from prolonged treatment (RR = 0.62, 95% confidence interval (95% CI): 0.42-0.93), no benefit was evident for erbB2-positive patients (RR = 1.1, 95% CI: 0.41-3.2). When the same analysis was restricted to ER-positive patients a similar difference in relative hazard was obtained but the difference was not strictly significant (P = 0.065).

CONCLUSIONS

For early stage breast cancer patients treated with adjuvant tamoxifen, overexpression of erbB2 is an independent marker of poor prognosis. The results suggest that overexpression decreases the benefit from prolonged tamoxifen treatment.

A comparison between flow cytometric assessment of S-phase fraction and Nottingham histologic grade as prognostic instruments in breast cancer

Flow cytometric DNA analysis with assessment of S-phase fraction and DNA ploidy was compared to Nottingham histologic grade. The study population consisted of 654 patients who presented between 1987 and 1996 with primary operable breast cancer and whose tumours had been analysed for S-phase fraction and DNA ploidy at the time of surgery. Grade, tumour size, node status, steroid receptor status, age, S-phase fraction and DNA ploidy were analysed univariately and multi-variately in a Cox proportional hazard analysis. In the univariate analyses all parameters were statistically significantly associated with breast cancer mortality during the follow-up period of 2-11 years. The most powerful predictor of death from breast cancer in the multiple regression analysis was grade. Patients with grade 1 tumours have excellent prognosis. We conclude that tumour grade is a strong prognostic indicator applicable to all breast cancer patients, regardless of size and nodal status, and advocate its general use.

C-erbB-2 overexpression and survival in early onset breast cancer

Young breast cancer patients have a decreased survival rate and it has been demonstrated that young age is an independent predictor of adverse prognosis. Overexpression of c-erbB-2 protein (also known as HER-2/neu) has been shown to be a prognostic indicator in breast cancer in general and especially among patients with axillary nodal metastases. The present study was initiated to determine the prognostic significance of c-erbB-2 protein overexpression in early onset breast cancer. A population consisting of 110 young breast cancer patients, < or = 36-year-old at diagnosis, was analyzed with immunohistochemical staining for c-erbB-2 protein. Thirty patients (27%) were found to overexpress the c-erbB-2 protein. C-erbB-2 positivity was significantly associated with poor survival when all patients were included in the analysis (P = 0.002) and for patients with axillary nodal metastases (P = 0.0007). No such association was found for node-negative patients. Furthermore, the difference in prognosis in relation to c-erbB-2 among node-positive patients was maintained, when these were stratified in groups treated or not treated with adjuvant chemotherapy. The study indicates that overexpression of c-erbB-2 protein is a strong prognostic factor in young breast cancer patients with axillary nodal metastases. Moreover, the adverse prognosis associated with c-erbB-2 overexpression in node-positive patients was observed whether or not the patients had received adjuvant chemotherapy.

Results of two or five years of adjuvant tamoxifen correlated to steroid receptor and S-phase levels. South Sweden Breast Cancer Group, and South-East Sweden Breast Cancer Group

A Swedish cooperative trial demonstrated that 5 years of adjuvant tamoxifen was more beneficial than 2 years of tamoxifen in the treatment of postmenopausal women with estrogen receptor (ER) positive, early stage, invasive breast cancer. The main aim of the present study was to investigate the importance of progesterone receptor (PgR) and ER concentration levels for patients participating in the trial and still distant recurrence free two years after the primary operation. Subgroup analyses revealed that only patients with ER positive and PgR positive breast cancer had improved distant recurrence free survival (DRFS) by prolonged tamoxifen therapy (p = 0.0016). Patients with ER negative and PgR negative as well as ER positive and PgR negative tumors showed no significant effect of prolonged tamoxifen (p = 0.53 and p = 0.80, respectively). The percentage of ER negative and PgR positive breast cancers was too small (2.2%) for any meaningful subgroup analysis. There was a significant positive trend that the concentration level of PgR (high positive vs. low positive vs. negative) decreased the recurrence rate for those with prolonged therapy. No corresponding pattern was found for the ER content. S-phase fraction did not correlate to the recurrence rate of PgR positive breast cancers. Patients recurring during tamoxifen therapy had receptor negative tumors to a greater extent than those recurring after tamoxifen treatment. In conclusion, prolonged tamoxifen therapy for 5 years instead of 2 years was found to be beneficial for patients with ER positive and PgR positive breast cancer, whereas three extra years of tamoxifen had little or no effect for patients with ER positive but PgR negative tumors as well as for steroid receptor negative patients.

p53 status: an indicator for the effect of preoperative radiotherapy of rectal cancer

BACKGROUND

Rectal carcinoma is a common malignancy, with a history of high local recurrence rates following surgery. In recent years. preoperative radiotherapy and refined surgical technique have improved local control rates.

AIM

To investigate the relationship between expression of nuclear p53 protein and the outcome in rectal carcinoma, with and without short-term preoperative radiotherapy.

MATERIAL

Specimens from 163 patients from the Southeast Swedish Health Care region included in the Swedish rectal cancer trial between 1987-1990.

METHOD

New sections from the paraffin blocks of the preoperative biopsy and the surgical specimen were examined immunohistochemically using a p53 antibody (PAb 1801).

RESULT

Expression of nuclear p53 protein was seen in 41% of the tumours. The p53 negative patients treated with preoperative radiotherapy had a significant reduction of local failure compared with the non-irradiated p53 negative patients (P = 0.0008). In contrast, p53 positive patients showed no benefit from preoperative radiotherapy. The interaction between p53 status and the benefit of radiotherapy was statistically significant (P = 0.018).

CONCLUSION

Expression of nuclear p53 protein in rectal carcinoma seems to be a significant predictive factor for local treatment failure after preoperative radiotherapy. Further investigations are necessary to select patients for preoperative treatment based on analysis of the preoperative biopsies.