The correlation of 18F-FDG PET/CT metabolic parameters, clinicopathological factors, and prognosis in breast cancer.

PURPOSE: To study the imaging parameters of 18F-fluorodeoxy glucose (18F-FDG) in breast cancer on positron emission tomography/computed tomography (PET/CT)-the correlation of clinical pathological factors and prognosis among the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of lesions for patients. METHODS: From January 2012 to December 2014, a total of 125 female patients were treated in our hospital for the first time and were diagnosed as breast cancer by histopathology. They were selected as the research subjects. All of them had complete 18F-FDG PET/CT examination data before surgery, the postoperative clinicopathological information, and follow-up data. They were divided into the event group (38 cases) and the event-free group (87 cases) according to whether local recurrence or distant metastasis occurred after the follow-up, with the follow-up time 4-60 months. The correlation on 18F-FDG PET/CT metabolic parameters of breast cancer with clinicopathological factors and prognosis was retrospectively evaluated. RESULTS: The primary lesions of 125 cases with breast cancers all had higher 18F-FDG uptake, and the SUVmax, MTV, and TLG of the primary tumors in the event group were significantly higher than those in the event-free group (t = 2.645, 2.782, 15.263, p = 0.011, 0.008, 0.000), p < 0.05; SUVmax, MTV, and TLG of primary breast cancer have no correlation with age and tumor site of patient (p > 0.05); there were statistically significant differences in the SUVmax, MTV, and TLG of primary tumor in the comparison of different tumor size, T stage, N stage, and histological grades (p < 0.05); all of SUVmax, MTV, and TLG in the estrogen receptor (ER) and/or progesterone receptor (PR) positive groups were lower than those in the negative group, with statistically significant difference (p < 0.05); the SUVmax, MTV, and TLG of human epidermal growth factor receptor 2 (HER2) positive group, proliferating cell nuclear antigen (Ki-67) high expression group were higher than those in the negative group and low expression group, with statistically significant difference (p < 0.05). There were 38 recurrence and metastasis cases within 125 cases with breast cancer in 5 years after operation, with the total recurrence and metastasis rate as 30.40% (38/125). The event-free survival rate in the SUVmax ≥ 8.64 group was significantly lower than that in the SUVmax < 8.64 group (p < 0.01). CONCLUSIONS: The metabolic parameters of 18F-FDG PET/CT in breast cancer can reflect the biological behavior of the tumor indirectly; therefore, it was studied on the related correlation to provide the guidance of clinical individualized comprehensive treatment and prognostic judgment.

Sentinel lymph node biopsy in patients affected by breast ductal carcinoma in situ with and without microinvasion: Retrospective observational study.

With the introduction of an organized mammographic screening, the incidence of ductal carcinoma in situ (DCIS) has experienced an important increase. Our experience with sentinel lymph node biopsy (SLNB) among patients with DCIS is reviewed.We collected retrospective data on patients operated on their breasts for DCIS (pTis), DCIS with microinvasion (DCISM) (pT1mi) and invasive ductal carcinoma (IDC) sized ≤2 cm (pT1) between January 2002 and June 2016, focusing on the result of SLNB.543 DCIS, 84 DCISM, and 2111 IDC were included. In cases of DCIS and DCISM, SLNB resulted micrometastatic respectively in 1.7% and 6.0% of cases and macrometastatic respectively in 0.9% and 3.6% of cases. 5-year disease-free survival and overall survival in DCISM and IDC were similar, while significantly longer in DCIS. 5-year local recurrence rate of DCIS and DCISM were respectively 2.5% and 7.9%, and their 5-year distant recurrence rate respectively 0% and 4%. IDC, tumor grading ≥2 and lymph node (LN) macrometastasis were significant predictors for decreased overall survival. Significant predictors for distant metastases were DCISM, IDC, macroscopic nodal metastasis, and tumor grading ≥2. Predictors for the microinvasive component in DCIS were tumor multifocality/multicentricity, grading ≥2, ITCs and micrometastases.Our study suggests that despite its rarity, sentinel node metastasis may also occur in case of DCIS, which in most cases are micrometastases. Even in the absence of an evident invasive component, microinvasion should always be suspected in these cases, and their management should be the same as for IDC.

Claudin-4 Expression Is Associated With Disease-Free Survival in Breast Carcinoma-in-Situ: Mean Follow-up of 8.2 Years.

INTRODUCTION: Claudins are tight junctions associated with breast cancer prognosis. The claudin-low intrinsic subtype of invasive carcinoma is associated with high-grade carcinoma, low junction molecule expression, and worse response to chemotherapy. However, it is not known whether the expression of claudins may provide clues as to carcinoma-in-situ (CIS) prognosis. The aim of this study was evaluate claudin-4 expression in CIS and its association with disease-free survival and histologic type of local recurrence (in situ or invasive). METHODS: A tissue microarray block, constructed from 137 pure CIS paraffin blocks, was submitted to immunohistochemical staining for claudin-4, ß-catenin, E-cadherin, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, and Ki-67. A claudin-4 score categorized samples as claudin-4-low or -high. Clinical and treatment data were obtained from medical records. RESULTS: Claudin-4 expression was evaluated in 86 samples; 88.4% were high and 11.6% low. Mean follow-up was 98.4 months, and the local recurrence rate was 10.4%. There was a significant difference in disease-free survival between claudin-4-high and -low (4.9 and 1.9 years, respectively, P = .02); however, there was no difference between them in histologic type of recurrence (invasive or in situ) (P = .44). CONCLUSION: In our samples, high claudin-4 expression in CIS was more frequent than low expression. Claudin-4-low expression had a worse prognosis in CIS (inferior disease-free survival), but it was similar to high claudin-4 in histologic type of local recurrence.

Understanding Disparities in Breast Cancer Care in Memphis, Tennessee.

Although significant progress has been made in improving breast cancer survival, disparities among racial, ethnic, and underserved groups still exist. The goal of this investigation is to quantify racial disparities in the context of breast cancer care, examining the outcomes of recurrence and mortality in the city of Memphis. Patients with a biopsy-proven diagnosis of breast cancer from January 1, 2002, through December 31, 2012, were obtained from the tumor registry. Black patients were more likely to have advanced (II, III, or IV) clinical stage of breast cancer at diagnosis versus white patients. Black breast cancer patients had a two times higher odds of recurrence (95% confidence interval: 1.4, 3.0) after adjusting for race and clinical stage. Black breast cancer patients were 1.5 times more likely to die (95% confidence interval: 1.2, 1.8), after adjusting for race; age at diagnosis; clinical stage; ER, PR, HER2 status; and recurrence. Black women with stages 0, I, II, and III breast cancer all had a statistically significant longer median time from diagnosis to surgery than white women. Black patients were more likely to have advanced clinical stages of breast cancer at diagnosis versus white patients on a citywide level in Memphis. Black breast cancer patients have higher odds of recurrence and mortality when compared with white breast cancer patients, after adjusting for appropriate demographic and clinical attributes. More work is needed to develop, evaluate, and disseminate interventions to decrease inequities in timeliness of care for breast cancer patients.

Breast-conserving surgery followed by whole-breast irradiation offers survival benefits over mastectomy without irradiation.

BACKGROUND: The prognostic equivalence between mastectomy and breast-conserving surgery (BCS) followed by radiotherapy was shown in pivotal trials conducted decades ago. Since then, detection and treatment of breast cancer have improved substantially and recent retrospective analyses point towards a survival benefit for less extensive breast surgery. Evidence for the association of such survival data with locoregional recurrence rates is largely lacking. METHODS: The Swedish Multicentre Cohort Study prospectively included clinically node-negative patients with breast cancer who had planned sentinel node biopsy between 2000 and 2004. Axillary lymph node dissection was undertaken only in patients with sentinel node metastases. For the present investigation, adjusted survival analyses were used to compare patients who underwent BCS and postoperative radiotherapy with those who received mastectomy without radiotherapy. RESULTS: Of 3518 patients in the Swedish Multicentre Cohort Study, 2767 were included in the present analysis; 2338 had BCS with postoperative radiotherapy and 429 had mastectomy without radiotherapy. Median follow-up was 156 months. BCS followed by whole-breast irradiation was superior to mastectomy without irradiation in terms of both overall survival (79·5 versus 64·3 per cent respectively at 13 years; P < 0·001) and breast cancer-specific survival (90·5 versus 84·0 per cent at 13 years; P < 0·001). The local recurrence rate did not differ between the two groups. The axillary recurrence-free survival rate at 13 years was significantly lower after mastectomy without irradiation (98·3 versus 96·2 per cent; P < 0·001). CONCLUSION: The present data support the superiority of BCS with postoperative radiotherapy over mastectomy without radiotherapy. The axillary recurrence rate differed significantly, and could be one contributing factor in a complex explanatory model.

Cytoplasmic FOXP1 expression is correlated with ER and calpain II expression and predicts a poor outcome in breast cancer.

BACKGROUND: Nuclear forkhead box protein P1 (N-FOXP1) expression in invasive breast cancer has been documented in the literature. However, the FOXP1 expression patterns at different stages of breast cancer progression are largely unknown, and the significance of cytoplasmic FOXP1 (C-FOXP1) expression in breast cancer has not been well illustrated. The aims of this study were to investigate FOXP1 expression patterns in invasive ductal carcinoma (IDC), ductal carcinoma in situ (DCIS), atypical ductal hyperplasia (ADH) and usual ductal hyperplasia (UDH), and to analyze the clinicopathological relevance of C-FOXP1 and its prognostic value in IDC. METHODS: N-FOXP1 and C-FOXP1 expression in cases of IDC, DCIS, ADH and UDH was determined using immunohistochemistry. The correlation between C-FOXP1 expression and clinicopathological parameters as well as the overall survival (OS) and disease-free survival (DFS) rates of patients with IDC were analyzed. RESULTS: Exclusive N-FOXP1 expression was found in 85.0% (17/20), 40.0% (8/20), 12.2% (5/41) and 10.8% (9/83) of UDH, ADH, DCIS, and IDC cases, respectively, and exclusive C-FOXP1 expression was observed in 0% (0/20), 0% (0/20), 4.9% (2/41), and 31.3% (26/83) of the cases, respectively. Both N- and C-FOXP1 staining were observed in 15.0% (3/20), 60.0% (12/20), 82.9% (34/41) and 48.2% (40/83) of the above cases, respectively, while complete loss of FOXP1 expression was observed in only 9.6% (8/83) of IDC cases. Estrogen receptor (ER) expression in C-FOXP1-positive IDC cases (31/66, 47.0%) was significantly lower than that in C-FOXP1-negative cases (13/17, 76.5%) (p = 0.030). Calpain II expression was observed in 83.3% (55/66) of C-FOXP1-positive IDC cases, which was significantly higher than that in C-FOXP1-negative cases (9/17, 52.9%) (p = 0.007). Calpain II was significantly associated with pAKT (p = 0.029), pmTOR (p = 0.011), p4E-BP1 (p < 0.001) and p-p70S6K (p = 0.003) expression levels. The 10-year OS and DFS rates of the C-FOXP1-positive patients were 60.5% and 48.7%, respectively, both of which were lower than those of the C-FOXP1-negative patients (93.3, 75.3%). The OS curve showed a dramatic impact of C-FOXP1 status on OS (p = 0.045). CONCLUSIONS: Cytoplasmic relocalization of FOXP1 protein was a frequent event in breast IDC. Calpain II might play an important role in nucleocytoplasmic trafficking of FOXP1 and the AKT pathway might be involved in this process. C-FOXP1 expression was inversely associated with ER expression and might be a predictor of poor OS in patients with IDC.

Survival outcomes of patients with lobular carcinoma in situ who underwent bilateral mastectomy or partial mastectomy.

AIM: To compare the survival outcomes between patients treated with bilateral mastectomy and partial mastectomy alone as the initial surgical management for primary lobular carcinoma in situ (LCIS). PATIENTS AND METHODS: Patients with histologically confirmed LCIS underwent partial mastectomy alone or bilateral mastectomy were identified by the SEER*Stat database (version 8.3.2) released in 2016. The primary outcome measure was all-cause mortality and the secondary outcome measure was breast cancer-specific mortality. RESULTS: Of the 5964 cases included in the analysis, 208 cases underwent bilateral mastectomy and 5756 cases underwent partial mastectomy alone. The 1-, 5- and 10-year estimated overall survival rates were 99.7%, 96.7% and 91.7%, respectively. Univariate and multivariate proportional hazards regression (Cox) analyses showed no significant difference between the risk of all-cause mortality in the bilateral mastectomy group compared with the partial mastectomy group (HR = 1.106, 95% confidence interval [CI] 0.350-3.500, P = 0.86). In propensity score-matched model, bilateral mastectomy still did not show benefit to overall mortality (HR = 2.248, 95% CI 0.451-11.200). Patients older than 60 years of age showed a higher risk of all-cause mortality (HR = 7.593, 95% CI 5.357-10.764, P < 0.0001). No risk factors, including surgery type, were identified for breast cancer-specific survival. CONCLUSIONS: Survival outcomes of patients with LCIS who underwent partial mastectomy without radiotherapy were not inferior to patients who underwent bilateral prophylactic mastectomy. Breast cancer-specific mortality in patients with LCIS was extremely low; aggressive prophylactic surgery like bilateral prophylactic mastectomy should not be advocated for most patients with LCIS.

Prognostic value of stromal tumour infiltrating lymphocytes and programmed cell death-ligand 1 expression in breast cancer.

AIM: The present work aims to evaluate the presence of stromal tumour-infiltrating lymphocytes (TILs) and programmed cell death-ligand 1 (PDL1) expression in breast carcinomas and their correlation with available clinicopathological features. METHODS: Two independent series of invasive breast cancer (IBC), one including ductal carcinoma in situ (DCIS) pair-matched cases, were selected, and quantification of TILs was accomplished in each case. Immunohistochemistry was also performed to evaluate the expression of PDL1. RESULTS: In both cohorts evaluated, increased stromal TILs and PDL1 expression were present in about 10% of IBCs, being significantly associated with each other and both with grade 3 and triple-negative subtype. We observed a similar distribution of stromal TILs and PDL1 expression between DCIS and IBC. Finally, we observed that increased stromal TILs and PDL1 expression were significantly associated with cancer stem cell (CSC) markers, basal cell markers and vimentin expression. Interestingly, in IBC cases with vimentin expression, increased stromal TILs, as well as decreased PDL1 expression, disclosed a better clinical outcome, independently of the main classical BC prognostic factors. CONCLUSIONS: We have confirmed the association of stromal TILs and PDL1 expression with aggressive forms of BC and that both are already found in in situ stages. We also showed that stromal TILs and PDL1 expression are associated with clinical outcome in cases enriched for a mesenchymal immunophenotype. We describe for the first time a close relationship between CSC markers and PDL1 expression.

Population-Based Analysis of Breast Cancer Incidence and Survival Outcomes in Women Diagnosed with Lobular Carcinoma In Situ.

PURPOSE: A diagnosis of lobular carcinoma in situ (LCIS) is associated with an increased risk of developing breast cancer, although little data exist on long-term patient outcomes, including those who develop subsequent breast malignancies. METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was used to identify women with a histological diagnosis of LCIS between 1983 and 2014. The incidence and clinicopathologic features of subsequent malignancies were then examined, and the Kaplan-Meier method and multivariable Cox PH regression used to obtain breast cancer-specific survival (BCSS) estimates and associated hazard ratios. RESULTS: Overall, 19,462 women swith a mean age at LCIS diagnosis of 53.7 years, and a 10- and 20-year cumulative incidence of subsequent breast malignancy of 11.3% [95% confidence interval (CI) 10.7-11.9%] and 19.8% (95% CI 18.8-20.9) met the eligibility criteria. At a median follow-up of 8.1 years (range 0-30.9) a total of 1837 primary breast cancers were diagnosed, of which 55.2% were diagnosed in the ipsilateral breast. Most breast cancers were of low/intermediate grade, hormone receptor-positive, and diagnosed in early stages. Of subsequent malignancies, invasive ductal carcinoma (IDC) distributed equally across both breasts, whereas invasive lobular carcinoma (ILC) was more likely to present in the ipsilateral breast (69.0% ILC vs. 49.2% IDC; p < 0.001). On multivariable analysis, type of surgical treatment for LCIS had no affect on long-term survival (p = 0.44). The 10- and 20-year BCSS for women with LCIS was 98.9 and 96.3%, respectively. CONCLUSION: Women with LCIS who are diagnosed with a subsequent primary breast cancer are often diagnosed in early stages and have excellent BCSS.

Neoadjuvant Chemotherapy Creates Surgery Opportunities For Inoperable Locally Advanced Breast Cancer.

Neoadjuvant chemotherapy (NAC), the systematic chemotherapy given to patients with locally advanced and inoperable breast caner, has been proven to be of great clinical values. Many scientific reports confirmed NAC could effectively eliminate sub-clinical disseminated lesions of tumor, and improve long-term and disease-free survival rate of patients with locally advanced breast cancer (LABC); however, up to now, LABC is still a serious clinical issue given improved screening and early diagnosis. This study, with main focus on inoperable LABC, investigated the values of NAC in converting inoperable LABC into operable status and assessed the prognosis. Sixty-one patients with inoperable LABC were initially treated with neoadjuvant chemotherapy; their local conditions were improved to operable status. Radical surgery was exerted on 49 patients. Original chemotherapy was performed after surgery, followed by local radiotherapy. And endocrine therapy was optional according to the hormone receptor status. The quality of life for most patients with skin diabrosis was obviously improved because their local conditions were under control. For all recruited cases, the survival duration and life quality were significantly improved in patients who finished both NAC and surgery compared to those who did not. Further more, this study demonstrates improved prognostic consequences.

Cause-specific mortality in women with breast cancer in situ.

The long-term mortality remains unknown in women diagnosed with breast cancer in situ (BCIS). Here, we assessed the cause-specific mortality in BCIS patients. This population-based cohort study included 12,243 women diagnosed with BCIS in Sweden between 1980 and 2011. Patients were followed until death, emigration, or 31 December 2013, whichever came first. The 30-year cumulative incidence of breast cancer-specific mortality was 6.3%, which is considerably lower than 49.7% observed for other-cause mortality. Women diagnosed with BCIS were more likely to die from breast cancer (standardized mortality ratio [SMR], 3.85; 95% CI, 3.47-4.27) but less likely to die from cardiovascular disease (SMR, 0.88; 95% CI, 0.82-0.95) than women in the general population. Specifically, the SMRs for breast cancer-specific mortality decreased over time from 5.19 (95% CI, 3.95-6.81) among BCIS diagnosed during 1980-1989 to 3.03 (95% CI, 2.35-3.91) among those diagnosed during 2000-2011. Furthermore, higher risk of death from other causes was seen among those with older age at BCIS diagnosis, lower levels of education, nulliparity, higher Charlson Comorbidity Index, and being hospitalized before BCIS diagnosis; whereas, lower risk of death from breast cancer was seen among BCIS diagnosed in the later time period and those with younger age at first birth. We conclude that most women diagnosed with BCIS die from causes other than breast cancer, which highlights the need for actions not only to reduce nonbreast cancer mortality but also to identify patient where extensive curative BCIS treatment is not adding to survival.

Breast carcinoma in situ: An observational study of tumor subtype, treatment and outcomes.

BACKGROUND & AIMS: To evaluate the clinical presentation, treatment and outcome of patients with breast carcinoma in situ (BCIS) with special emphasis on the role of the tumor subtype and local treatment in these patients. METHODS: Using data obtained by the Surveillance, Epidemiology, and End Results (SEER) program from 2010-2013, a retrospective, population-based cohort study was conducted to investigate tumor subtype-specific differences in various characteristics, overall survival (OS) and breast cancer-specific mortality (BCSM). RESULTS: In all, 6867 patients with BCIS were eligible during the 2010-2013 study period. Compared with the hormone receptor (HoR)+/HER- subgroup, patients with triple negative (TN) breast cancer were more likely to have tumors that were higher in grade and larger in size; they were also more likely to have tumors with ductal and comedo histology and were less likely to have tumors with cribriform and papillary histology (each P < 0.05). During the follow-up period, patients with TN breast cancer had an OS of 97.0% compared with 98.6 % in the HoR+/HER- subgroup (P < 0.05). Furthermore, the BCSM rate was 1.0% for the TN group compared with 0.1% for the HoR+/HER- subgroup (P < 0.05). Multivariate analysis revealed that patients with TN MBC had a poorer OS and BCSM (P <0.05). Multivariate analysis of OS with respect to the local treatment history showed that patients who received breast-conserving surgery (BCS) combined with radiotherapy (R) were more likely to have an improved OS (P < 0.05). Moreover, the results demonstrated that patients who underwent SLNB were more likely to have a lower BCSM (P < 0.05). CONCLUSIONS: The results demonstrate that BCIS appears to alter the prognosis associated with the TN subtype. Meanwhile, BCS plus R was a preferable option and resulted in survival rates that were better than those achieved with mastectomy; thus, SLNB should be considered as an appropriate assessment of axillary staging in patients with BCIS.

Lobular Carcinoma In Situ: A 15-Year Single Institution Review.

The optimal management of lobular carcinoma In Situ (LCIS) has largely been debated. This study evaluated practice patterns and outcomes in women diagnosed with LCIS at a single institution from 2000 to 2014. Patient characteristics, histology, method of diagnosis, and management were examined in relation to disease-free survival, and overall survival (OS). A total of 209 patients were identified. Surgical management in the majority of patients was excisional biopsy or local excision. Patients diagnosed with LCIS by core biopsy were less likely to have mastectomy as compared with other methods of initial diagnosis (P = 0.01). A total of 108 (90.8%) patients received chemoprevention (CP) counseling, and 47 (43.5%) used chemoprevention. Estimated five-year disease-free survival rate was 96.3 per cent (95% confidence interval (CI): 92.0-98.3%) and OS rate was 98.6 per cent (95% CI: 94.6-99.7%). Older age was associated with a higher risk of subsequent breast cancer (hazard ratio (HR): 1.04; 95% CI: 1.01-1.07; P = 0.01). Older age (HR: 1.06; 95% CI: 1.02-1.11; P = 0.004) and diagnosis in the earlier years of the study period (HR: 0.65; 95% CI: 0.48-0.89; P = 0.007) were significantly associated with worse OS in multivariate analysis. LCIS has a favorable prognosis and is most commonly managed conservatively.

Does breast screening offer a survival benefit? A retrospective comparative study of oncological outcomes of screen-detected and symptomatic early stage breast cancer cases.

INTRODUCTION: Mammography screening reduces breast cancer mortality by up to 32%. However, some recent studies have questioned the impact of non-palpable breast cancer detection on mortality reduction. The aim of this study was to analyse the clinicopathological and long-term follow-up data of early stage screened and symptomatic breast cancer patients. PATIENTS AND METHOD: The institutional prospectively led database was systematically analysed for breast cancer cases diagnosed via the mammography screening program from 2002 to 2009. As a control group, symptomatic early stage breast cancer patients were collected randomly from the same database and matched for age and follow-up period. All medical records were reviewed retrospectively. RESULTS: Data from 298 breast cancer patients were collected from 47,718 mammography screenings. In addition, 331 symptomatic breast cancer patients were randomly selected. The screened group presented a significantly lower median tumour size (P < 0.00001). The incidence of negative regional lymph nodes was significantly higher in the screened group (P < 0.0006). The incidence of chemotherapy was 17% higher in the symptomatic group (P = 4*10-5). At the median follow-up of 65 and 80 months, the screened group did not exhibit better overall (P = 0.717) or disease-free survival (P = 0.081) compared to the symptomatic group. CONCLUSION: Our results do not suggest that mammography screening does not reduce breast cancer mortality but the mammography screening did not bring any significant improvement in patient overall or disease-free survival for the early stage breast cancer patients compared to the symptomatic group. The drawback of symptomatic early stage tumours compared to non-palpable tumours could be equalized by modern multimodality oncology treatments.

Overdiagnosis and overtreatment associated with breast cancer mammography screening: A simulation study with calibration to population-based data.

OBJECTIVES: The magnitude of overdiagnosis of breast cancer associated with mammography screening remains controversial because of methodological issues. The objective of this study was to quantify overdiagnosis and overtreatment associated with a population-based screening programme, taking into account lead time and uncertainty concerning baseline incidence of breast cancers. MATERIAL AND METHODS: A simulation model was developed to replicate incidence and detection rates of breast cancer observed in the Isère Département, France. The parameters of the model were estimated using an approximate Bayesian computation method. RESULTS: For women aged 50-74 years during the 2007-2010 period, overdiagnosis of non-progressive breast cancers accounted for 17.0% (95% credibility interval (CI): 2.5%-35.5%) of all in situ cancers diagnosed, 5.5% (95% CI: 0.8%-9.8%) of all invasive cancers diagnosed, and 20.3% (95% CI: 3.0%-38.9%) of in situ and 13.0% (95% CI: 2.2%-23.3%) of invasive screen detected breast cancers. The estimates of overdiagnosis due to competitive causes of death were 1.0% (95% CI: 0.2%-%1.7) and 1.1% (95% CI: 0.6%-1.7%) for all in situ and invasive cancers diagnosed, respectively, and 1.3% (95% CI: 0.2%-2.0%) and 2.6% (95% CI: 1.4%-4.0%) of all in situ and invasive screen detected breast cancers, respectively. Among 1000 screen-detected cancers in 2010, 155 (95% CI: 27-284), 134 (95% CI: 10-242) and 140 (95% CI: 25-254) women underwent breast conserving surgery, lymph node dissection and radiation therapy for overdiagnosed cancers, respectively. CONCLUSION: Our estimates of overdiagnosis should be balanced against the reduction of breast cancer mortality to assess the value of breast cancer screening programme.