Review, evaluation, and discussion of the challenges of missing value imputation for mass spectrometry-based label-free global proteomics.

In this review, we apply selected imputation strategies to label-free liquid chromatography-mass spectrometry (LC-MS) proteomics datasets to evaluate the accuracy with respect to metrics of variance and classification. We evaluate several commonly used imputation approaches for individual merits and discuss the caveats of each approach with respect to the example LC-MS proteomics data. In general, local similarity-based approaches, such as the regularized expectation maximization and least-squares adaptive algorithms, yield the best overall performances with respect to metrics of accuracy and robustness. However, no single algorithm consistently outperforms the remaining approaches, and in some cases, performing classification without imputation sometimes yielded the most accurate classification. Thus, because of the complex mechanisms of missing data in proteomics, which also vary from peptide to protein, no individual method is a single solution for imputation. On the basis of the observations in this review, the goal for imputation in the field of computational proteomics should be to develop new approaches that work generically for this data type and new strategies to guide users in the selection of the best imputation for their dataset and analysis objectives.

The effect of hospital volume on the outcome of breast cancer surgery.

BACKGROUND: This study was conducted to investigate whether annual surgical unit caseload affects extent of breast cancer surgery, breast cancer recurrence or breast cancer-specific survival. METHODS: In a population-based cohort study, 12,604 women diagnosed with breast cancer in Finland during the years 1998-2001 were followed up until the end of year 2008. Surgical units were divided into subgroups: >200, 100-200, 50-99 or <50 breast cancer operations per year. Information on patients, treatment, and follow-up was obtained from two national registries. The analyses were adjusted for age and disease stage. The reliability of the registry information was validated by comparison with information from one hospital area. Cox proportional hazard and logistic regression models were employed in the analyses. RESULTS: Validation of the registry data showed that date of diagnosis, age, stage, extent of surgery, and date and cause of death were reliably recorded in the registers. Information on radiotherapy was obtained by combining different registry data. Data on local and distant recurrences were not reliable enough to allow analyses. Patients in hospitals with smaller caseloads underwent mastectomy more often than those operated in hospitals with higher caseloads (P < 0.001). Higher caseloads were also related to improved survival (P = 0.031). CONCLUSIONS: National registries should include information on both local and distant recurrences in order to provide reliable population-based data for evaluation of treatment results. Centralization of surgery to high-volume centers is supported by a higher incidence of conservative surgery and better survival.

Bone morphogenetic protein 7 expression associates with bone metastasis in breast carcinomas.

BACKGROUND: We recently showed that bone morphogenetic protein 7 (BMP7) is overexpressed in primary breast tumors. Here we explored the clinical significance of BMP7 expression in breast cancer. MATERIALS AND METHODS: This study included 483 breast cancer patients with complete clinicopathological information and up to 15 years of follow-up. Samples contained 241 lobular carcinomas, 242 ductal carcinomas, and 40 local recurrences. BMP7 protein expression was determined using immunohistochemistry. RESULTS: BMP7 was expressed in 47% of the primary tumor samples and 13% of the local recurrences. The primary tumors expressed BMP7 more often than the corresponding local recurrences (P = 0.004). BMP7 expression was dependent on the tumor subtype; 57% of the lobular carcinomas but only 37% of the ductal carcinomas were BMP7 positive (P = 0.0001). BMP7 expression was associated with accelerated bone metastasis formation (P = 0.040), especially in ductal carcinomas (P = 0.033), and multivariate analysis confirmed that BMP7 is an independent prognostic indicator for early bone metastasis development (P = 0.032). CONCLUSION: BMP7 is clearly associated with bone metastasis formation and thus might have clinical utility in identification of patients with increased risk of bone metastasis. This is the first time that bone inducing factor BMP7 has been linked to the bone metastasis process in breast cancer.

Clinical validation of the LKB model and parameter sets for predicting radiation-induced pneumonitis from breast cancer radiotherapy.

The choice of the appropriate model and parameter set in determining the relation between the incidence of radiation pneumonitis and dose distribution in the lung is of great importance, especially in the case of breast radiotherapy where the observed incidence is fairly low. From our previous study based on 150 breast cancer patients, where the fits of dose-volume models to clinical data were estimated (Tsougos et al 2005 Evaluation of dose-response models and parameters predicting radiation induced pneumonitis using clinical data from breast cancer radiotherapy Phys. Med. Biol. 50 3535-54), one could get the impression that the relative seriality is significantly better than the LKB NTCP model. However, the estimation of the different NTCP models was based on their goodness-of-fit on clinical data, using various sets of published parameters from other groups, and this fact may provisionally justify the results. Hence, we sought to investigate further the LKB model, by applying different published parameter sets for the very same group of patients, in order to be able to compare the results. It was shown that, depending on the parameter set applied, the LKB model is able to predict the incidence of radiation pneumonitis with acceptable accuracy, especially when implemented on a sub-group of patients (120) receiving [see text]|EUD higher than 8 Gy. In conclusion, the goodness-of-fit of a certain radiobiological model on a given clinical case is closely related to the selection of the proper scoring criteria and parameter set as well as to the compatibility of the clinical case from which the data were derived.

Association of overexpression of tumor suppressor protein p53 with rapid cell proliferation and poor prognosis in node-negative breast cancer patients.

BACKGROUND: Recent evidence indicates that a subset of axillary node-negative (ANN) breast cancer patients can benefit from adjuvant therapy. Reliable prognostic markers are needed, however, to help clinicians identify these patients and arrive at more rational treatment decisions. PURPOSE: Mutations of the p53 tumor suppressor gene often result in overexpression of the p53 protein. In this study, we evaluated the prognostic significance of p53 protein overexpression in patients with ANN breast cancer. We also studied the association between the tumor cell proliferation rate and overexpression of the p53 and c-erbB-2 proteins, both of which have been implicated in cell cycle control. The c-erbB-2 protein is the product of the ERBB2 gene. METHODS: Two hundred eighty-nine ANN cases were randomly selected from a population-based cohort of patients who had not received any kind of adjuvant chemotherapy or endocrine therapy. Overexpression of the p53 and c-erbB-2 proteins was studied immunohistochemically in archival paraffin-embedded tumor samples, using the CM-1 polyclonal and the TAb 250 monoclonal antibodies, respectively. The tumor cell proliferation rate was measured as the S-phase fraction by DNA flow cytometry. Statistical analyses were performed using BMDP software. RESULTS: High-level p53 protein overexpression, found in 41 of the 289 tumors, was most common in tumors with high histologic grade, negative estrogen receptor status, c-erbB-2 protein overexpression, DNA index greater than 1.3, or high S-phase fraction. The lowest S-phase levels were found in tumors with neither p53 nor c-erbB-2 protein overexpression; the highest levels were seen in tumors showing overexpression of both proteins (P less than .0001). Both p53 and c-erbB-2 overexpression, as well as tumor size, had independent prognostic value in multivariate analysis. Eight-year survival of patients with p53 protein overexpression was 56% compared with 81% in patients with no overexpression (relative risk, 3.7; P less than .0001). If the S-phase fraction was included in a Cox regression analysis, however, only the tumor size and the S-phase fraction emerged as independent predictors of survival. CONCLUSIONS: Overexpression of the p53 and c-erbB-2 proteins indicates a high malignant potential in ANN breast cancer, but it is not a significant prognostic factor independent of the cell proliferation rate. The correlation between overexpression of these proteins and an increased S-phase fraction suggests that they may confer a proliferative advantage to cancer cells in vivo.

Low biologic aggressiveness in breast cancer in women using hormone replacement therapy.

PURPOSE: Hormone replacement therapy (HRT) has been associated with an increased risk for breast cancer. Cancers in women who use HRT are often less advanced, and lower mortality has been reported in those who use HRT than in nonusers. We sought to explain this by a comparison of indicators of tumor aggressiveness in patients who received HRT with those in patients who did not. PATIENTS AND METHODS: A population-based cohort of 477 postmenopausal women with breast cancer were interviewed for the use, type, and duration of HRT. Clinical variables and indicators of tumor aggressiveness (histologic grade, hormone receptors, DNA ploidy, S-phase fraction, and c-erbB-2 oncoprotein overexpression) were analyzed. RESULTS: Breast tumors from HRT users were smaller (odds ratio, 0.47; P=.005), had better histologic differentiation (P=.04), and had a lower proliferation rate (S-phase fraction, P=.009) than tumors from nonusers. These differences persisted after adjustments for age and method of diagnosis (mammography screening v self-referral) by multiple logistic regression. No significant differences were observed in the estrogen (ER) or progesterone receptor content, c-erbB-2 oncogene overexpression, or axillary node involvement. A subgroup analysis showed that the tumor proliferation rates among HRT users were significantly lower only if HRT had been used at the time of diagnosis (P=.001). The type of HRT (estrogen v combination of estrogen and progesterone) was not associated with any clinical parameter or tumor phenotype. The association of HRT with lower proliferation rate and smaller tumor size was exclusively caused by ER-positive tumors (P=.0001 and P=.0035 v P > .1, respectively). CONCLUSION: The results indicate that breast cancer in women who receive HRT is biologically less aggressive than those without previous HRT. The lower cell-proliferation rate and smaller tumor size found in ER-positive tumors from current HRT users suggest a direct ER-mediated growth inhibitory effect of HRT on established breast tumors. This may at least partly explain why breast cancer in HRT users has a more favorable clinical course.

Loss of estrogen receptor in recurrent breast cancer is associated with poor response to endocrine therapy.

PURPOSE: Up to 30% to 40% of metastases from hormone receptor-positive primary breast cancer do not respond to endocrine therapy. We studied how often hormone receptor status changes between primary and recurrent tumors and whether such a change might explain unresponsiveness to endocrine therapy. PATIENTS AND METHODS: Primary breast cancer samples and matched asynchronous recurrences were studied from 50 patients who had not received any adjuvant therapy. Estrogen receptor (ER) and progesterone receptor (PR) status was determined immunohistochemically from histologically representative formalin-fixed paraffin-embedded tumor samples. ER status was ascertained by mRNA in situ hybridization. RESULTS: Thirty-five (70%) of 50 primary tumors were positive for ER and 30 (60%) for PR. Hormone receptor status of the recurrent tumor differed from that of the primary tumor in 18 cases (36%). Discordant cases were due to the loss of ER (n = 6), loss of PR (n = 6), or loss of both receptors (n = 6). Receptor-negative primary tumors were always accompanied by receptor-negative recurrences. Among 27 patients with ER-positive primary tumors, loss of ER was a significant predictor (P = .0085) of poor response to subsequent endocrine therapy. Only one of eight patients (12.5%) with lost ER expression responded to tamoxifen therapy, whereas the response rate was 74% (14 of 19) for patients whose recurrent tumors retained ER expression. CONCLUSION: Loss of ER expression in recurrent breast cancer should be considered as a cause for poor response to endocrine therapy in primarily ER-positive patients. We conclude that analysis of recurrent tumor samples may improve the predictive value of ER and PR assays.

Cathepsin D expression detected by immunohistochemistry has independent prognostic value in axillary node-negative breast cancer.

PURPOSE: Increased expression of the lysosomal protease cathepsin D (CD) has been implicated in the metastatic progression of breast cancer. This study was designed to determine the prognostic significance of CD expression in axillary node-negative (ANN) breast cancer. The relationship of CD expression and onset of soft tissue recurrences and visceral metastatases was also studied. PATIENTS AND METHODS: We analyzed a population-based group of 262 ANN breast cancer patients, none of whom had received any adjuvant chemotherapy or endocrine therapy. An immunohistochemical method based on a new monoclonal antibody (1C11) with a distinct epitope specificity made it possible to study CD expression from archival paraffin-embedded specimens and to distinguish staining in tumor cells from the high-level expression found in tumor-infiltrating macrophages. RESULTS: High-level CD expression, as defined by cytoplasmic immunoreactivity in greater than 10% of the cancer cells, was found in 95 cases (36%). High-level CD expression was associated with large primary tumor size (P = .014), but not with histologic grade, estrogen and progesterone receptors, DNA index, or S-phase fraction, or with c-erbB-2 and p53 overexpression. Patients with CD-positive tumors developed significantly more often both soft tissue recurrences and visceral metastases (P = .0007) and had a significantly shorter disease-free survival (P < .0001). Eight-year overall survival of patients with high-level CD expression was 64% as compared with 90% in those with low-level expression (relative risk, 2.97; 95% confidence interval [Cl], 1.6 to 4.4; P < .0001). According to a Cox multivariate model and a regression-tree analysis, high-level CD expression was an independent predictor of poor overall survival in conjunction with tumor size and S-phase fraction. CONCLUSION: These results indicate that CD expression determined by immunohistochemistry is a powerful prognostic factor in ANN breast cancer. The most significant prognostic information was obtained when CD expression (predicting metastatic activity) was combined with estimate of cell-proliferation rate (S-phase fraction).

Safety and efficacy results of a randomized trial comparing adjuvant toremifene and tamoxifen in postmenopausal patients with node-positive breast cancer. Finnish Breast Cancer Group.

PURPOSE: In this multicenter trial, toremifene 40 mg/d was compared with tamoxifen 20 mg/d, both given orally for 3 years to postmenopausal, axillary node-positive women after breast surgery. PATIENTS AND METHODS: The first 899 patients (toremifene, n = 459; tamoxifen, n = 440) of the total of 1,480 patients accrued to the trial were included in this scheduled safety analysis. The mean follow-up time was 3.4 years. RESULTS: The two treatment groups were well balanced with respect to patient and disease characteristics. The subjective side-effect profile was similar in both treatment groups. Slightly more vascular complications (deep vein thromboses, cerebrovascular events, and pulmonary embolisms) were seen among tamoxifen-treated patients (5.9%) as compared with toremifene-treated patients (3.5%) (P: =.11), whereas bone fractures (P: =.09) and vaginal leukorrhea (P: =.05) were more common in the toremifene group. The number of subsequent second cancers was similar. The breast cancer recurrence rate was 23.1% (n = 106) in the toremifene group and 26.1% (n = 115) in the tamoxifen group (P: =.31). When only patients with estrogen receptor (ER)-positive cancer were considered (n = 556), the risk for breast cancer recurrence was nonsignificantly lower among the toremifene-treated women, with a hazards ratio of 0.74 (90% confidence interval, 0.52 to 1.04; P: =.14). The mean time to breast cancer recurrence and overall survival were similar in both groups. CONCLUSION: The side-effect profile of toremifene resembles that of tamoxifen. The efficacy of toremifene seems to be no less than that of tamoxifen. The trend for fewer breast cancer recurrences in the ER-positive subgroup is encouraging, but a longer follow-up is needed to confirm this.

Omission of histologic grading from clinical decision making may result in overuse of adjuvant therapies in breast cancer: results from a nationwide study.

PURPOSE: To investigate the influence of routinely performed histologic grading on breast cancer outcome prediction and patient selection for adjuvant therapy. PATIENTS AND METHODS: The analysis is based on a cohort of 2,842 women diagnosed with breast cancer and comprising 91% of all breast cancers diagnosed in five defined geographical regions in Finland in 1991 through 1992. Data on clinicopathologic factors and follow-up were collected from hospital case records and national registries. Histologic grade assessed at diagnosis and other clinicopathologic data were available for 1,554 operable unilateral invasive carcinomas. The relative value of grade with respect to competing prognostic factors was estimated with the Cox proportional hazards model and logistic regression. Interactions and nonlinearity of factors were accounted for by using an artificial neural network. RESULTS: Histologic grade was correlated strongly with survival in the entire series and in all subgroups studied. Women with well-differentiated node-negative cancer had a 97% 5-year distant disease-free survival rate as compared with 78% for women with poorly differentiated cancer. Grade was an independent prognostic factor in multivariate models and increased the predictive accuracy of a neural network model. Inclusion of grade data in a Cox multivariate model based on tumor size and hormone receptor status in node-negative cancer increased the proportion of patients with 5% or less risk for distant recurrence at 5 years from 15% to 54%. CONCLUSION: Even when assessed by pathologists who have no special training in breast cancer pathology, histologic grade has substantial and independent prognostic value in breast cancer. Omission of grading from clinical decision making may result in considerable overuse of adjuvant therapies.

Combination chemotherapy versus single-agent therapy as first- and second-line treatment in metastatic breast cancer: a prospective randomized trial.

PURPOSE: We report results of a randomized prospective study that compared single agents of low toxicity given both as the first-line and second-line chemotherapy with combination chemotherapy in advanced breast cancer with distant metastases. PATIENTS AND METHODS: Patients in the single-agent arm (n = 153) received weekly epirubicin (E) 20 mg/m2 until progression or until the cumulative dose of 1,000 mg/m2, followed by mitomycin (M) 8 mg/m2 every 4 weeks, and those in the combination chemotherapy arm (n = 150) were first given cyclophosphamide 500 mg/m2, E 60 mg/m2, and fluorouracil 500 mg/m2 three times per week (CEF) followed by M 8 mg/m2 plus vinblastine (V) 6 mg/m2 every 4 weeks. Exclusion criteria included age greater than 70 years, World Health Organization (WHO) performance status greater than 2, prior chemotherapy for metastatic disease, and presence of liver metastases in patients younger than 50. RESULTS: An objective response (complete [CR] or partial [PR]) was obtained in 55%, 48%, 16%, and 7% of patients treated with CEF, E, M, and MV, respectively. A response to CEF tended to last longer than a response to E (median, 12 v 10.5 months; P = .07). Treatment-related toxicity was less in the single-agent arm and quality-of-life (QOL) analysis favored the single-agent arm. No significant difference in time to progression or survival was found between the two arms. Similarly, no difference in survival was found when the patients who received both the planned first-and second-line treatments were compared or when survival was calculated from the beginning of the second-line therapy. CONCLUSION: Patients treated with single-agent E followed by single-agent M had similar survival, but less treatment-related toxicity and better QOL as compared with those treated with CEF followed by MV.

Amplification of chromosomal region 20q13 in invasive breast cancer: prognostic implications.

Amplification of the chromosome 20q13 region was recently discovered in breast cancer by comparative genomic hybridization and subsequently further defined by fluorescence in situ hybridization with specific probes. The target gene of the amplification remains unknown. Here, fluorescence in situ hybridization with a cosmid probe for the minimal region of amplification (RMC20C001) was used to study 20q13 amplification in 132 primary breast carcinomas and 11 metastases. The size of the amplicon was studied with four flanking probes. Thirty-eight (29%) primary tumors and 3 (27%) metastases showed increased copy number of the RMC20C001 probe (>1.5-fold relative to the p-arm control). Nine (6.8%) of the primary tumors were highly (>3-fold) amplified. Although the size and location of the amplified region varied from one tumor to another, only the RMC20C001 probe was consistently amplified. 20q13 amplification was significantly associated with a high histological grade (P = 0.01), DNA aneuploidy (P = 0.01), and high S-phase fraction (P = 0.0085). High-level amplification was also associated with short disease-free survival of patients with node-negative breast cancer (P = 0.002). We conclude that high-level 20q13 amplification may be an indicator of poor clinical outcome in node-negative breast cancer and that this chromosomal region is likely to contain a gene with an important role in breast cancer progression. A large definitive study is warranted to assess the independent prognostic value of 20q13 amplification.

Attitudes and Stereotypes in Lung Cancer versus Breast Cancer.

Societal perceptions may factor into the high rates of nontreatment in patients with lung cancer. To determine whether bias exists toward lung cancer, a study using the Implicit Association Test method of inferring subconscious attitudes and stereotypes from participant reaction times to visual cues was initiated. Participants were primarily recruited from an online survey panel based on US census data. Explicit attitudes regarding lung and breast cancer were derived from participants' ratings (n = 1778) regarding what they thought patients experienced in terms of guilt, shame, and hope (descriptive statements) and from participants' opinions regarding whether patients ought to experience such feelings (normative statements). Participants' responses to descriptive and normative statements about lung cancer were compared with responses to statements about breast cancer. Analyses of responses revealed that the participants were more likely to agree with negative descriptive and normative statements about lung cancer than breast cancer (P<0.001). Furthermore, participants had significantly stronger implicit negative associations with lung cancer compared with breast cancer; mean response times in the lung cancer/negative conditions were significantly shorter than in the lung cancer/positive conditions (P<0.001). Patients, caregivers, healthcare providers, and members of the general public had comparable levels of negative implicit attitudes toward lung cancer. These results show that lung cancer was stigmatized by patients, caregivers, healthcare professionals, and the general public. Further research is needed to investigate whether implicit and explicit attitudes and stereotypes affect patient care.

Haplotype analysis in Icelandic and Finnish BRCA2 999del5 breast cancer families.

The 999del5 mutation is the single, strong BRCA2 founder mutation in Iceland and the most common BRCA1/2 founder mutation in Finland. To evaluate the origin and time since spreading of the 999del5 mutation in Iceland and in Finland, we constructed haplotypes with polymorphic markers within and flanking the BRCA2 gene in a set of 18 Icelandic and 10 Finnish 999del5 breast cancer families. All Icelandic families analysed shared a common core haplotype of about 1.7 cM. The common ancestors for the Icelandic families studied were estimated to trace back to 340-1000 years, not excluding the possibility that the mutation was brought to Iceland during the settlement of the country. Analysis of the Finnish families revealed two distinct haplotypes. A rare one, found in three families in the old settlement region in southwestern Finland, shared a four-marker (0.5 cM) core haplotype with the Icelandic 999del5 haplotype. A distinct approximately 6 cM haplotype was shared by seven 999del5 Finnish families estimated to have a common ancestry 140-300 years ago. These families cluster in two geographical regions in Finland, in the very same area as those with the rare haplotype and also in the most eastern, late settlement region of Finland. The results may indicate a common ancient origin for the 999del5 mutation in Iceland and in Finland, but distinct mutational events cannot be ruled out. The surprising finding of the same mutation in two completely different haplotypes in a sparsely populated area in Finland may suggest gene conversion.

Multiple founder effects and geographical clustering of BRCA1 and BRCA2 families in Finland.

In the Finnish breast and ovarian cancer families six BRCA1 and five BRCA2 mutations have been found recurrently. Some of these recurrent mutations have also been seen elsewhere in the world, while others are exclusively of Finnish origin. A haplotype analysis of 26 Finnish families carrying a BRCA1 mutation and 20 families with a BRCA2 mutation indicated that the carriers of each recurrent mutation have common ancestors. The common ancestors were estimated to trace back to 7-36 generations (150-800 years). The time estimates and the geographical clustering of these founder mutations in Finland are in concordance with the population history of this country. Analysis of the cancer phenotypes showed differential ovarian cancer expression in families carrying mutations in the 5' and 3' ends of the BRCA1 gene, and earlier age of ovarian cancer onset in families with BRCA1 mutations compared with families with BRCA2 mutations. The identification of prominent and regional BRCA1 and BRCA2 founder mutations in Finland will have significant impact on diagnostics in Finnish breast and ovarian cancer families. An isolated population with known history and multiple local founder effects in multigenic disease may offer distinct advantages also for mapping novel predisposing genes.

Biological, physical, mental and social dimensions of breast cancer: information based on routine case notes.

551 patients were diagnosed with breast cancer in Tampere University Hospital district, Finland between 1977 and 1980. The number of follow-up visits during the first 5 years was 8248. The biological, physical, mental and social dimensions of breast cancer were measured by death, recurrence of disease, Karnofsky score, physical or mental symptoms, and sick leave. The prevalence rates of an event and the incidence rates of the appearance or disappearance of an event were used to determine the indicators for these different dimensions of breast cancer. The study was based on hospital case notes. Data on death, recurrence, sick leave and Karnofsky score were well recorded, but physical or mental symptoms were recorded infrequently. There was a 4-fold difference between the highest and lowest prevalence for the different dimensions, but the trends were similar by follow-up time. The variation was also large for the incidence rates but the trends differed with length of follow-up time. The biological, physical, mental and social consequences of breast cancer differ in magnitude and have different trends over time, indicating that breast cancer is a different disease depending on the dimension and on the indicator under consideration.

Effect of age on the survival of breast cancer patients.

Despite numerous studies, the effect of patient age on the prognosis of breast cancer is still uncertain. The aim of this study was to assess the influence of age on long-term relative survival, to control the results for the extent of disease at diagnosis and assess the association between biological markers and age of the patients. A population-based survival study was made to assess the 5- and 10-year relative survival. All 17,856 female breast cancer patients diagnosed in Finland and reported to the Finnish Cancer Registry in 1977-1986 were included. The results were controlled for the extent of the disease. The markers of biological aggressiveness of tumours and patients' age were correlated in a prospectively collected subset of 2107 patients from the Tampere University area. The relative 5-year and 10-year survival rates (RSRs) were highest in women 46-50 years of age, whereas there was no significant difference between younger and older age groups. No consistent survival trends were observed among the age groups in local, node-negative disease, whereas in node-positive disease the 10-year relative survival was best for women 41-45 years (49%) and poorest in women over 75 years (35%). The youngest age groups were significantly more often oestrogen receptor-negative, but only small differences were observed for S-phase fraction and progesterone receptor positivity.

Ca 15-3 in the follow-up of localised breast cancer: a prospective study.

Altogether, 243 female breast cancer patients with localised disease diagnosed between 1991 and 1995 in the Tampere University Hospital area were followed prospectively after primary treatment until the first relapse. In the follow-up period, the serum tumour marker Ca 15-3 was analysed every 6 months to ascertain the validity of this marker in detecting the first relapse. The sensitivity and specificity of the test were analysed in different metastatic situations. During the 5 years of follow-up, 59 (24%) relapses were discovered. Ca 15-3 was elevated in 21/59 (36%) of the relapsed cases at least once. The 59 patients were subjected to 199 tests, of which 25 (13%) were positive. Among the 184 patients without recurrence, there were 6 (3%) with a positive Ca 15-3 level. The test failed to detect locoregional relapse or contralateral breast cancer. It was elevated in approximately half of bone-only metastases and in all of the liver-only metastases. In the pulmonary-only recurrences, the marker value was not elevated. We conclude that the Ca 15-3 tumour marker test is specific, but not sensitive enough to indicate the first relapse earlier than other methods. The positive predictive value especially remained poor in patients with a relatively good prognosis. Our results confirm that the test is not suitable alone for breast cancer follow-up.

Toremifene. where do we stand?

Toremifene is a chlorinated triphenylethylene that is indicated for postmenopausal breast cancer. For advanced disease, toremifene has been found to be as effective and at least as well tolerated as tamoxifen. The same appears to apply for adjuvant setting. After a total cumulative clinical exposure to toremifene of approximately 140000 patient-years, only 9 cases of endometrial carcinoma have been reported. The annual hazard rate (per 1000 patient-years) of developing endometrial carcinoma in breast cancer patients on adjuvant toremifene is 1.14 (versus tamoxifen 2.0 and placebo 0.4). Although toremifene (being a partial agonist) may unmask pre-existing endometrial tumours, there is no clinical data implying that it would per se cause endometrial carcinoma.

Information and communication in the context of a clinical trial.

The aim of this study was to determine the communicative needs of the patients in the context of being invited to participate in a clinical trial. A questionnaire was sent to 299 patients with breast cancer randomised in a trial of adjuvant therapy. It was returned by 261 (87%) of them. Ninety-one per cent (231/255) of the patients regarded the information provided as easy or quite easy to understand. However, the method of treatment allocation was unclear to most patients: 51% (128/251) thought that the doctor had chosen the treatment while only 23% (57/251) knew that they had been randomised. Younger and better educated patients had a better understanding. For 55% (125/226) of the patients written information had been helpful in decision making. This correlated highly with the education of the patient. Sixty-eight per cent (174/255) of the patients thought that they had enough time for decision-making. Less educated patients and older patients had needed more time. Eighty-seven per cent (218/251) were happy with their decision to participate. While most patients are satisfied with the information received, there is a poor understanding of how treatment is allocated. Information should be modified for older and less-educated patients. The needs of the patients when offered participation in a clinical trial are clear information, enough time to consider the options and psychological support.