Bo Baldetorp

Indicators of prognosis in node-negative breast cancer

Measures of the proliferative activity of tumor cells have prognostic value in patients with node-negative breast cancer. We studied 367 women in southern Sweden who had undergone surgical resection for such cancer. Tumor specimens were analyzed with DNA flow cytometry in order to estimate both the DNA content (ploidy) and the fraction of cells in the synthetic phase of the cell cycle (S phase). The median duration of follow-up was four years; 28 percent of the patients received adjuvant therapy, usually with tamoxifen (n = 83). A multivariate analysis based on complete data on 250 patients included the following covariates: age (greater than or equal to 75, 50 to 74, and less than or equal to 49 years), tumor size (less than or equal to 20 vs. greater than 20 mm), concentration of estrogen and progesterone receptors (less than 10 vs. greater than or equal to 10 fmol per milligram of protein), ploidy (diploid vs. nondiploid), and S-phase category (fraction of cells in S phase: less than 7.0 percent, 7.0 to 11.9 percent, and greater than or equal to 12 percent). The S-phase fraction yielded the most prognostic information, followed by progesterone-receptor status and tumor size. A prognostic model based on these three variables identified 37 percent of the patients as constituting a high-risk group with a fourfold increased risk of distant recurrence. In the remaining 63 percent of the patients, the five-year overall survival rate (92 +/- 4 [+/- SE] percent) did not differ from the expected age-adjusted rate for Swedish women. We conclude that a prognostic index that includes indicators of the proliferative activity of tumor cells may be able to identify women with node-negative breast cancer in whom the risk of recurrence is sufficiently low that adjuvant chemotherapy can be avoided.

ERBB2 amplification is associated with tamoxifen resistance in steroid-receptor positive breast cancer

Amplification and overexpression of the ERBB2 (HER-2/neu) oncogene has been implicated as contributing to the development of human breast cancer, and as a predictor of poor survival. In the present non-randomized study of 871 primary invasive breast tumours, ERBB2 activation was significantly correlated to a shorter disease-free and overall survival in the subgroup of patients receiving adjuvant tamoxifen therapy, but not in the untreated group. Further subcategorization demonstrated the relationship to poor prognosis to be confined to lymph node positive and steroid receptor-positive tumours. We suggest that steroid receptor and ERBB2-positive breast tumours are resistant to tamoxifen therapy and, supported by experimental evidence showing an oestrogen receptor dependent up-regulation of ERBB2 expression upon tamoxifen administration, possibly even growth stimulated by the drug.

Soft tissue leiomyosarcoma. A population-based epidemiologic and prognostic study of 48 patients, including cellular DNA content

Background. Leiomyosarcoma of soft tissue is a rare tumor. There are different opinions regarding epidemiology and prognosis.

Correlation between p53, c-erbB-2, and topoisomerase II alpha expression, DNA ploidy, hormonal receptor status and proliferation in 356 node-negative breast carcinomas: prognostic implications

Various new prognostic indicators have been identified for mammary carcinomas, but the issue of their significance remains unsettled. The prognostic impact of p53, c‐erbB‐2, and topoisomerase IIα expression was investigated in relation to standard prognostic factors for carcinomas of the breast and to the tumour cell growth fraction. Paraffin‐embedded specimens of 356 node‐negative infiltrating ductal carcinomas were stained immunohistochemically using a polyclonal antiserum to c‐erb B‐2, and the monoclonal antibodies DO‐1 (p53), Ki‐S4 (topoisomerase IIα), and Ki‐S5 (Ki‐67). The patients were followed for a median duration of 99 months. Both p53 and c‐erb B‐2 were significantly associated with high tumour grade, large tumour size, DNA aneuploidy, lack of steroid hormone receptors, young age, and increased topoisomerase IIα and Ki‐67 expression levels. The correlation of p53 and c‐erb B‐2 was not significant. Topoisomerase IIα and Ki‐67 scores closely paralleled each other, indicating that both reflect the proliferative activity of tumour cells. A univariate analysis of overall (OS), specific (SS), and disease‐free survival (DFS) revealed all the above‐mentioned parameters to be statistically significant except patient age, which was relevant only to overall survival. Multivariate analysis with inclusion of all covariates selected tumour size and proliferation (topoisomerase IIα and Ki‐67) indices as independent predictors of survival in all three models. No additional information was gained by p53 or c‐erb B‐2. It is concluded that the proliferative activity, as assessed by topoisomerase IIα or Ki‐67 immunostaining, is the most useful indicator of breast cancer prognosis, except for tumour size. Copyright

Results of two or five years of adjuvant tamoxifen correlated to steroid receptor and S-phase levels

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.

Constitutive expression of the Wilms' tumor gene (WT1) in the leukemic cell line U937 blocks parts of the differentiation program

The Wilms tumor gene, WT1, encodes a zinc-finger DNA binding protein which is thought to function as a tissue specific transcription factor, regulating cell growth and differentiation. High expression of WT1 has been detected in a range of acute leukemias. To elucidate a role for WT1 in leukemogenesis, we transfected the monoblastic cell line U937, which lacks detectable levels of endogenous WT1, with two isoforms of WT1. We showed that, in contrast to U937 control cells, cells constitutively expressing either of the isoforms, WT1(−KTS) or WT1(+KTS), did not respond to differentiation induction by retinoic acid or vitamin D3, as judged by the capacity to reduce nitro blue tetrazolium and morphology. Although U937 cells expressing WT1 were hampered in their ability to differentiate on incubation with retinoic acid and vitamin D3, the induced G1/G0-accumulation was similar to differentiating control cells treated with inducers. Furthermore, distinct effects on the maturation process were indicated by downregulation of the myeloid cell surface makers CD13 and CD15, while the upregulation of CD14 and CD11c on WT1 transfected cells was similar to control cells upon incubation with retinoic acid and vitamin D3. Taken together our results demonstrate that a constitutive expression of WT1 in the leukemic cell line U937 leads to impairment of differentiation responses, indicating that a high expression of WT1 can contribute to the differentiation block of acute leukemia.

Cellular DNA content and prognosis of high-grade soft tissue sarcoma: the Scandinavian Sarcoma Group experience.

The nuclear DNA content of 148 high-grade soft tissue sarcomas of the extremities and trunk was determined by flow cytometry, using tumor material from paraffin-embedded tissue. The patients were part of a prospective randomized clinical trial on the efficacy of adjuvant single-agent chemotherapy with doxorubicin. Chemotherapy did not improve the metastasis-free survival (MFS). After a median follow-up time of 48 months (range, 2 to 97), a multivariate analysis of prognostic factors for developing metastatic disease was performed. DNA aneuploidy was found to be an independent prognostic risk factor in addition to histologic malignancy grade IV, intratumoral vascular invasion, tumor size over 10 cm, and male sex. Patients with none or one risk factor had a 5-year MFS of 79%, with two risk factors 65%, with three risk factors 43%, and with four and five risk factors 0%. About one half (78 of 148) of the patients with three factors or less belonged to a group with a MFS over 60%. The combination of different risk factors, including DNA aneuploidy, seems to be a useful prognostic model for soft tissue sarcomas, which could be of value to select high-risk patients for further trials with adjunctive therapy.

Expression of cyclins E, A, and B, and prognosis in lymph node-negative breast cancer.

Unexpected outcomes in breast cancer demand a refinement of prognostic criteria. This study therefore investigated the prognostic relevance of cyclin expression in a cohort of 332 T1–T2 N0 infiltrating ductal carcinomas with long‐term follow‐up (median 99 months). By univariate analysis, tumour size, histopathological grade, hormone receptor content, cyclin E, cyclin B, and the Ki‐S5 (Ki‐67) index significantly predicted disease‐specific and metastasis‐free survival. Cyclin A did not achieve statistical significance. In a multivariate analysis, both cyclin E [relative risk (RR) 2.01, p = 0.021] and cyclin B (RR 1.85, p = 0.033) were selected as independent prognosticators of metastasis‐free survival when the Ki‐67 index was omitted, but only cyclin E expression was associated with disease‐specific survival (RR 2.56, p = 0.006). When Ki‐67 was included as a covariate, cyclin E lost its significance with respect to disease‐specific survival but remained significant for metastasis‐free survival. In an analogous analysis including Ki‐67, the number of concurrently overexpressed cyclins did not attain statistical significance regarding disease‐specific survival but was selected as the leading predictor of metastatic disease. It is concluded that combined overexpression of cyclins may imply genetic instability enhancing metastatic potential, but that survival ultimately depends on the proliferative activity of tumour cells. Copyright

Differential prognostic impact of the cyclins E and B in premenopausal and postmenopausal women with lymph node-negative breast cancer

Searching for new prognostic factors, we investigated the influence of cyclin expression on breast cancer prognosis. A total of 273 archival tumor specimens from patients with pT1/pT2 N0 breast cancers treated by surgery and local irradiation were immunostained for cyclins E, A and B. Outcome was evaluated as metastasis‐free (MFS) and disease‐specific survival (DSS) over a median observation period of 99 months. In postmenopausal women, DSS was significantly predicted by cyclin E, and in premenopausal patients by cyclin B. No statistical significance was found for cyclin A. When the prognostic impact of cyclins was compared to that of standard prognostic indicators in a multivariate analysis, both cyclin E and cyclin B were selected as independent predictors of survival in postmenopausal and premenopausal patients, respectively. After inclusion of Ki‐67 in the model, cyclin E lost its significance, whereas cyclin B remained the only independent prognostic factor with a hazard ratio of 4.5 (p = 0.026) for tumor‐related death. Assessment of cyclin expression may, therefore, refine current prognostic models if considered in relation to menopausal status. The prognostic relevance of cyclins is likely attributable to an influence on proliferation, cell survival and genetic instability. Awareness of the molecular mechanisms leading to deregulated cyclin expression may guide decisions for risk‐adapted therapy regimens.

Genetic Aberrations in Hypodiploid Breast Cancer : Frequent Loss of Chromosome 4 and Amplification of Cyclin D1 Oncogene

The evolution of somatic genetic aberrations in breast cancer has remained poorly understood. The most common chromosomal abnormality is hyperdiploidy, which is thought to arise via a transient hypodiploid state. However, hypodiploidy persists in 1 to 2% of breast tumors, which are characterized by a poor prognosis. We studied the genetic aberrations in 15 flow cytometrically hypodiploid breast cancers by comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). Surprisingly, numerous copy number gains were detected in addition to the copy number losses. The number of gains per tumor was 4.3 +/- 3.2 and that of losses was 4.5 +/- 3.3 (mean +/- SD), which is similar to that previously observed in hyperdiploid breast cancers. Gains at chromosomes or chromosomal regions at 11q13, 1q, 19, and 16p and losses of 2q, 4, 6q, 9p, 13, and 18 were most commonly observed. Compared with unselected breast carcinomas, hypodiploid tumors showed certain differences. Loss of chromosome 4 (53%) and gain of 11q13 (60%) were significantly more common in hypodiploid tumors. The gain at 11q13 was found by FISH to harbor amplification of the Cyclin D1 oncogene, which is therefore three to four times more common in hypodiploid than in unselected breast cancers (15 to 20%). Structural chromosomal aberrations (such as Cyclin D1 amplification) were present both in diploid and hypodiploid tumor cell populations, as assessed by FISH and CGH after flow cytometric sorting. Together these results indicate that hypodiploid tumors form a distinct genetic entity of invasive breast cancer, although they probably share a common genetic evolution pathway where structural chromosomal aberrations precede gross DNA ploidy changes.