Long-term Survival in Breast Cancer Patients Is Associated with Contralateral Parenchymal Enhancement at MRI: Outcomes of the SELECT Study

Background Several single-center studies found that high contralateral parenchymal enhancement (CPE) at breast MRI was associated with improved long-term survival in patients with estrogen receptor (ER)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. Due to varying sample sizes, population characteristics, and follow-up times, consensus of the association is currently lacking. Purpose To confirm whether CPE is associated with long-term survival in a large multicenter retrospective cohort, and to investigate if CPE is associated with endocrine therapy effectiveness. Materials and Methods This multicenter observational cohort included women with unilateral ER-positive HER2-negative breast cancer (tumor size ≤50 mm and ≤three positive lymph nodes) who underwent MRI from January 2005 to December 2010. Overall survival (OS), recurrence-free survival (RFS), and distant RFS (DRFS) were assessed. Kaplan-Meier analysis was performed to investigate differences in absolute risk after 10 years, stratified according to CPE tertile. Multivariable Cox proportional hazards regression analysis was performed to investigate whether CPE was associated with prognosis and endocrine therapy effectiveness. Results Overall, 1432 women (median age, 54 years [IQR, 47-63 years]) were included from 10 centers. Differences in absolute OS after 10 years were stratified according to CPE tertile as follows: 88.5% (95% CI: 88.1, 89.1) in tertile 1, 85.8% (95% CI: 85.2, 86.3) in tertile 2, and 85.9% (95% CI: 85.4, 86.4) in tertile 3. CPE was independently associated with OS, with a hazard ratio (HR) of 1.17 (95% CI: 1.0, 1.36; P = .047), but was not associated with RFS (HR, 1.11; P = .16) or DRFS (HR, 1.11; P = .19). The effect of endocrine therapy on survival could not be accurately assessed; therefore, the association between endocrine therapy efficacy and CPE could not reliably be estimated. Conclusion High contralateral parenchymal enhancement was associated with a marginally decreased overall survival in patients with estrogen receptor-positive and human epidermal growth factor receptor 2-negative breast cancer, but was not associated with recurrence-free survival (RFS) or distant RFS. Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Honda and Iima in this issue.

Abstract P3-03-18: M1 registration: Signaling patients who develop metachronous metastases after primary breast cancer

Background At the moment, over 180,000 breast cancer survivors are living in the Netherlands and survival after a breast cancer diagnosis and treatment is still increasing. Therefore, the number of survivors is rising, and these patients are at risk of metachronous metastases. Data at a national level on the development of metachronous metastases are limited, as this is not registered in the Netherlands Cancer Registry on a regular basis. Due to the vast amount of survivors, it is not feasible to actively monitor all patients to signal and register metachronous metastases. Applying machine learning may be an option to overcome this issue. The aim of our study is to develop a M1 detection algorithm based on hospital data to signal patients who developed metachronous metastases after their primary breast cancer treatment. Methods The Netherlands Cancer Registry (NCR) collects data on all individuals newly diagnosed with cancer in one of the 76 hospitals in the Netherlands since 1989. Dutch Hospital Data (DHD) collects and processes data from hospitals, including data on diagnosis and treatment. DHD data from 2019-2020 were linked to the NCR using a probabilistic matching method. We matched on date of birth, gender, diagnosis, postal code, hospital and patient ID. Column values that matched were weighted inversely proportional to the respective column’s probability distribution, where a match on a rare column value (e.g. postal codes with a relatively small population) increased the probability that the match was correct. Scores for each column were combined and patients with high matching scores were included in the algorithm development, validation and deployment. Actively signaled and manually registered data on metastases were available for subgroups of breast cancer patients included in previous studies (‘the golden standard’). First, 80% of these data was used to train the model, 20% was used to validate the model. Second, a pilot study was performed in which patients files were checked for 928 patients, sampled with variance in prediction probability, to evaluate a diverse range of cases. Results We included 4,395 patients. Variables that were included to predict metastases were i.e. specific medication for metastatic disease (palbociblib), counselling for metastatic breast cancer, Carcinoembryonic Antigen test, a confirmed diagnosis of metastases, and number of patient visits. The first validation step (including 20% of known data) showed that the model had a precision of 0.91 to predict metachronous metastases, 0.93 to predict free of metastases. The pilot study confirmed that a higher prediction probability of >0.8 correlated with a higher chance that a patient has metachronous metastases. However, false positive predictions did occur. Conclusion We developed a M1 detection algorithm to signal patients with metachronous metastases after breast cancer treatment on a national level. With this algorithm we are one step closer to identify all patients with metachronous metastases and to reach a complete registration of all breast cancer metastases reusing existing data sources. After review of patients with a high prediction probability, the model will be re-trained using these data and updated data from DHD.

Citation Format: Linda de Munck, Daan Knoors, Harm Buisman, Koen Scholman, Janneke Verloop, Sabine Siesling. M1 registration: Signaling patients who develop metachronous metastases after primary breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-03-18.

De-escalation of radiotherapy after primary chemotherapy in cT1-2N1 breast cancer (RAPCHEM; BOOG 2010-03): 5-year follow-up results of a Dutch, prospective, registry study

BACKGROUND

Primary chemotherapy in breast cancer poses a dilemma with regard to adjuvant locoregional radiotherapy, as guidelines for locoregional radiotherapy were originally based on pathology results of primary surgery. We aimed to evaluate the oncological safety of de-escalated locoregional radiotherapy in patients with cT1-2N1 breast cancer treated with primary chemotherapy, according to a predefined, consensus-based study guideline.

METHODS

In this prospective registry study (RAPCHEM, BOOG 2010-03), patients referred to one of 17 participating radiation oncology centres in the Netherlands between Jan 1, 2011, and Jan 1, 2015, with cT1-2N1 breast cancer (one to three suspicious nodes on imaging before primary chemotherapy, of which at least one had been pathologically confirmed), and who were treated with primary chemotherapy and surgery of the breast and axilla were included in the study. The study guideline comprised three risk groups for locoregional recurrence, with corresponding locoregional radiotherapy recommendations: no chest wall radiotherapy and no regional radiotherapy in the low-risk group, only local radiotherapy in the intermediate-risk group, and locoregional radiotherapy in the high-risk group. Radiotherapy consisted of a biologically equivalent dose of 25 fractions of 2 Gy, with or without a boost. During the study period, the generally applied radiotherapy technique in the Netherlands was forward-planned or inverse-planned intensity modulated radiotherapy. 5-year follow-up was assessed, taking into account adherence to the study guideline, with locoregional recurrence rate as primary endpoint. We hypothesised that 5-year locoregional recurrence rate would be less than 4% (upper-limit 95% CI 7·8%). This study was registered at ClinicalTrials.gov, NCT01279304, and is completed.

FINDINGS

838 patients were eligible for 5-year follow-up analyses: 291 in the low-risk group, 370 in the intermediate-risk group, and 177 in the high-risk group. The 5-year locoregional recurrence rate in all patients was 2·2% (95% CI 1·4-3·4). The 5-year locoregional recurrence rate was 2·1% (0·9-4·3) in the low-risk group, 2·2% (1·0-4·1) in the intermediate-risk group, and 2·3% (0·8-5·5) in the high-risk group. If the study guideline was followed, the locoregional recurrence rate was 2·3% (0·8-5·3) for the low-risk group, 1·0% (0·2-3·4) for the intermediate-risk group, and 1·4% (0·3-4·5) for the high-risk group.

INTERPRETATION

In this study, the 5-year locoregional recurrence rate was less than 4%, which supports our hypothesis that it is oncologically safe to de-escalate locoregional radiotherapy based on locoregional recurrence risk, in selected patients with cT1-2N1 breast cancer treated with primary chemotherapy, according to this predefined, consensus-based study guideline.

FUNDING

Dutch Cancer Society.

TRANSLATION

For the Dutch translation of the abstract see Supplementary Materials section.

Opportunities and obstacles in linking large health care registries: the primary secondary cancer care registry - breast cancer

Background

The growing volume of health data provides new opportunities for medical research. By using existing registries, large populations can be studied over a long period of time. Patient-level linkage of registries leads to even more detailed and extended information per patient, but brings challenges regarding responsibilities, privacy and security, and quality of data linkage. In this paper we describe how we dealt with these challenges when creating the Primary Secondary Cancer Care Registry (PSCCR)- Breast Cancer.

Methods

The PSCCR – Breast Cancer was created by linking two existing registries containing data on 1) diagnosis, tumour and treatment characteristics of all Dutch breast cancer patients (NCR), and 2) consultations and diagnoses from primary care electronic health records of about 10% of Dutch GP practices (Nivel-PCD). The existing registry governance structures and privacy regulations were incorporated in those of the new registry. Privacy and security risks were reassessed. Data were restricted to females and linked using postal code and date of birth. The breast cancer diagnosis was verified in both registries and for a subsample of 44 patients with the GP as well.

Results

A collaboration agreement was signed in which the organisations retained data responsibility and accountability for ‘their’ registry. A Trusted Third Party performed the record linkage. Ten percent of the patients with breast cancer could be linked to the primary care registry, as was expected based on the coverage of Nivel-PCD, and finally 7 % could be included. The breast cancer diagnosis was verified by the GP in 42 of the 44 patients.

Conclusions

We developed and validated a procedure for patient-level linkage of health data registries without a unique identifier, while preserving the integrity and privacy of the original registries. The method described may help researchers wishing to link existing health data registries.

Abstract P3-12-06: Prognosis of pregnancy-associated breast cancer: Inferior outcome in patients diagnosed during second and third gestational trimesters and lactation

BACKGROUND Pregnancy-associated breast cancer (PABC), although most commonly defined as breast cancer diagnosed during pregnancy or within one year following delivery, knows a variety of definitions, likely related to the diversity of reported clinicopathological features and prognosis. More insight into the different breast cancer subgroups during pregnancy, the time after delivery and the postpartum period is therefore warranted. METHODS Patients with breast cancer diagnosed during pregnancy or within six months after delivery between January 1, 1988 and July 1, 2019, were included. Pregnant patients were subdivided according to gestational trimester, and postpartum patients according to lactational status. To investigate the influence of pregnancy and lactation on the histopathologic profile, these subgroups were compared to non-PABC patients matched for age at diagnosis, year at diagnosis, grade and ER status. Pearson Chi-square tests were used to compare clinicopathologic characteristics, while Kaplan-Meier/logrank/Cox regression methods were used to perform overall survival (OS) analysis. RESULTS Overall, 662 PABC patients were included, of which 73.6% were diagnosed during pregnancy. Median age at diagnosis was 34 years, with a median follow-up of 6.5 years. Overall, PABC patients as a group showed an advanced stage at diagnosis and an inferior OS at 5-years (75.4% vs. 83.2%, p = 0.000) compared to 1,392 non-PABC patients. In subgroup analysis, PABC patients within their first trimester showed a significantly lower tumor size and stage as compared to other trimesters. Patients diagnosed during the first trimester and postpartum non-lactating patients had a relatively good OS (81.3% and 77.9%, respectively) versus patients diagnosed during the second and third trimesters and during lactation (OS 60.0%, 64.9% and 65.6%, respectively, p = 0.003). In multivariate Cox regression, trimester of diagnosis, year of diagnosis, PR status, stage at diagnosis and surgery-or-not were significant contributors to OS. CONCLUSION In this large PABC cohort, uniquely specified by gestational trimester, an inferior outcome was found for patients diagnosed within the second and third gestational trimesters and during postpartum lactation, compared to first trimester and non-lactating postpartum patients. These findings indicate that PABC is clinically a heterogeneous group of breast cancer patients that should be redefined based on trimester of diagnosis and postpartum lactational status.

Citation Format: Britt BM Suelmann, Carsten FJ Bakhuis, Carmen van Dooijeweert, Janneke Verloop, Ronald P Zweemer, Sabine C Linn, Elsken van der Wall, Paul J van Diest. Prognosis of pregnancy-associated breast cancer: Inferior outcome in patients diagnosed during second and third gestational trimesters and lactation [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-12-06.

Adverse health effects after breast cancer up to 14 years after diagnosis

BACKGROUND

The number of breast cancer survivors increases, but information about long-term adverse health effects in breast cancer survivors is sparse. We aimed to get an overview of the health effects for which survivors visit their general practitioner up to 14 years after diagnosis.

METHODS

We retrieved data on 11,671 women diagnosed with breast cancer in 2000-2016 and 23,242 age and sex matched controls from the PSCCR-Breast Cancer, a database containing data about cancer diagnosis, treatment and primary healthcare. We built Cox regression models for 685 health effects, with time until the health effect as the outcome and survivor/control and cancer treatment as predictors. Models were built separately for four age groups (aged 18/44, 45/59, 60/74 and 75/89) and two follow-up periods (1/4 and 5/14 years after diagnosis).

RESULTS

229 health effects occurred statistically significantly more often in survivors than in controls (p < 0.05). Health effects varied by age, time since diagnosis and treatment, but coughing, respiratory and urinary infections, fatigue, sleep problems, osteoporosis and lymphedema were statistically significantly increased in breast cancer survivors. Osteoporosis and chest symptoms were associated with hormone therapy; respiratory and skin infections with chemotherapy and lymphedema and skin infections with axillary dissection.

CONCLUSIONS

Breast cancer survivors may experience numerous adverse health effects up to 14 years after diagnosis. Insight in individual risks may assist healthcare professionals in managing patient expectations and improve monitoring, detection and treatment of adverse health effects.

Prognosis of pregnancy-associated breast cancer: inferior outcome in patients diagnosed during second and third gestational trimesters and lactation

PURPOSE

Pregnancy-associated breast cancer, although most commonly defined as breast cancer diagnosed during pregnancy or ≤1 year following delivery, knows a variety of definitions, likely related to the diversity of reported clinicopathological features and prognosis. More insight into the different breast cancer subgroups during pregnancy, time after delivery and the postpartum period is therefore warranted.

METHODS

Patients with breast cancer diagnosed during pregnancy or ≤6 months postdelivery were included, and subdivided according to gestational trimester, and postpartum patients according to lactational status. Subgroups were compared to matched non-PABC patients, to investigate the influence of pregnancy and lactation on clinical course and outcome.

RESULTS

Overall, 662 PABC patients were included (median age 34 years, median follow-up 6.5 years). PABC patients showed an advanced stage at diagnosis and an inferior 5-years-OS (75.4% vs. 83.2%, p = 0.000) compared to 1392 matched non-PABC patients. In subgroup analysis, first trimester PABC patients showed a significantly lower tumor size and stage as compared to other trimesters. Patients diagnosed during the first trimester and postpartum non-lactating patients had a relatively good OS (81.3% and 77.9%, respectively) versus patients diagnosed during the second and third trimesters and during lactation (OS 60.0%, 64.9% and 65.6%, respectively, p = 0.003).

CONCLUSION

In this large (uniquely specified) PABC cohort, an inferior outcome was found for patients diagnosed within the second and third gestational trimesters and during lactation. These findings indicate that PABC is clinically a heterogeneous group of breast cancer patients that should be redefined based on trimester of diagnosis and lactational status.

Impact on Quality of Documentation and Workload of the Introduction of a National Information Standard for Tumor Board Reporting

PURPOSE

Tumor boards, clinical practice guidelines, and cancer registries are intertwined cancer care quality instruments. Standardized structured reporting has been proposed as a solution to improve clinical documentation, while facilitating data reuse for secondary purposes. This study describes the implementation and evaluation of a national standard for tumor board reporting for breast cancer on the basis of the clinical practice guideline and the potential for reusing clinical data for the Netherlands Cancer Registry (NCR).

METHODS

Previously, a national information standard for breast cancer was derived from the corresponding Dutch clinical practice guideline. Using data items from the information standard, we developed three different tumor board forms: preoperative, postoperative, and postneoadjuvant-postoperative. The forms were implemented in Amphia Hospital’s electronic health record. Quality of clinical documentation and workload before and after implementation were compared.

RESULTS

Both draft and final tumor board reports were collected from 27 and 31 patients in baseline and effect measurements, respectively. Completeness of final reports increased from 39.5% to 45.4% (P = .04). The workload for tumor board preparation and discussion did not change significantly. Standardized tumor board reports included 50% (61/122) of the data items carried in the NCR. An automated process was developed to upload information captured in tumor board reports to the NCR database.

CONCLUSION

This study shows implementation of a national standard for tumor board reports improves quality of clinical documentation, without increasing clinical workload. Simultaneously, our work enables data reuse for secondary purposes like cancer registration.

Identification of Risk of Cardiovascular Disease by Automatic Quantification of Coronary Artery Calcifications on Radiotherapy Planning CT Scans in Patients With Breast Cancer

Importance

Cardiovascular disease (CVD) is common in patients treated for breast cancer, especially in patients treated with systemic treatment and radiotherapy and in those with preexisting CVD risk factors. Coronary artery calcium (CAC), a strong independent CVD risk factor, can be automatically quantified on radiotherapy planning computed tomography (CT) scans and may help identify patients at increased CVD risk.

Objective

To evaluate the association of CAC with CVD and coronary artery disease (CAD) in patients with breast cancer.

Design, Setting, and Participants

In this multicenter cohort study of 15 915 patients with breast cancer receiving radiotherapy between 2005 and 2016 who were followed until December 31, 2018, age, calendar year, and treatment-adjusted Cox proportional hazard models were used to evaluate the association of CAC with CVD and CAD.

Exposures

Overall CAC scores were automatically extracted from planning CT scans using a deep learning algorithm. Patients were classified into Agatston risk categories (0, 1-10, 11-100, 101-399, >400 units).

Main Outcomes and Measures

Occurrence of fatal and nonfatal CVD and CAD were obtained from national registries.

Results

Of the 15 915 participants included in this study, the mean (SD) age at CT scan was 59.0 (11.2; range, 22-95) years, and 15 879 (99.8%) were women. Seventy percent (n = 11 179) had no CAC. Coronary artery calcium scores of 1 to 10, 11 to 100, 101 to 400, and greater than 400 were present in 10.0% (n = 1584), 11.5% (n = 1825), 5.2% (n = 830), and 3.1% (n = 497) respectively. After a median follow-up of 51.2 months, CVD risks increased from 5.2% in patients with no CAC to 28.2% in patients with CAC scores higher than 400. After adjustment, CVD risk increased with higher CAC score (hazard ratio [HR]CAC = 1-10 = 1.1; 95% CI, 0.9-1.4; HRCAC = 11-100 = 1.8; 95% CI, 1.5-2.1; HRCAC = 101-400 = 2.1; 95% CI, 1.7-2.6; and HRCAC>400 = 3.4; 95% CI, 2.8-4.2). Coronary artery calcium was particularly strongly associated with CAD (HRCAC>400 = 7.8; 95% CI, 5.5-11.2). The association between CAC and CVD was strongest in patients treated with anthracyclines (HRCAC>400 = 5.8; 95% CI, 3.0-11.4) and patients who received a radiation boost (HRCAC>400 = 6.1; 95% CI, 3.8-9.7).

Conclusions and Relevance

This cohort study found that coronary artery calcium on breast cancer radiotherapy planning CT scan results was associated with CVD, especially CAD. Automated CAC scoring on radiotherapy planning CT scans may be used as a fast and low-cost tool to identify patients with breast cancer at increased risk of CVD, allowing implementing CVD risk-mitigating strategies with the aim to reduce the risk of CVD burden after breast cancer.

Trial Registration

ClinicalTrials.gov Identifier: NCT03206333.

Impact of the COVID-19 pandemic on diagnosis, stage, and initial treatment of breast cancer in the Netherlands: a population-based study

BACKGROUND

The onset of the COVID-19 pandemic forced the Dutch national screening program to a halt and increased the burden on health care services, necessitating the introduction of specific breast cancer treatment recommendations from week 12 of 2020. We aimed to investigate the impact of COVID-19 on the diagnosis, stage and initial treatment of breast cancer.

METHODS

Women included in the Netherlands Cancer Registry and diagnosed during four periods in weeks 2-17 of 2020 were compared with reference data from 2018/2019 (averaged). Weekly incidence was calculated by age group and tumor stage. The number of women receiving initial treatment within 3 months of diagnosis was calculated by period, initial treatment, age, and stage. Initial treatment, stratified by tumor behavior (ductal carcinoma in situ [DCIS] or invasive), was analyzed by logistic regression and adjusted for age, socioeconomic status, stage, subtype, and region. Factors influencing time to treatment were analyzed by Cox regression.

RESULTS

Incidence declined across all age groups and tumor stages (except stage IV) from 2018/2019 to 2020, particularly for DCIS and stage I disease (p < 0.05). DCIS was less likely to be treated within 3 months (odds ratio [OR]wks2-8: 2.04, ORwks9-11: 2.18). Invasive tumors were less likely to be treated initially by mastectomy with immediate reconstruction (ORwks12-13: 0.52) or by breast conserving surgery (ORwks14-17: 0.75). Chemotherapy was less likely for tumors diagnosed in the beginning of the study period (ORwks9-11: 0.59, ORwks12-13: 0.66), but more likely for those diagnosed at the end (ORwks14-17: 1.31). Primary hormonal treatment was more common (ORwks2-8: 1.23, ORwks9-11: 1.92, ORwks12-13: 3.01). Only women diagnosed in weeks 2-8 of 2020 experienced treatment delays.

CONCLUSION

The incidence of breast cancer fell in early 2020, and treatment approaches adapted rapidly. Clarification is needed on how this has affected stage migration and outcomes.

Abstract P2-13-21: Predicting symptoms and diseases after breast cancer treatment: Development of a nomogram

Background: Women with breast cancer can experience a variety of late adverse effects, depending on age, treatment and time since diagnosis. We developed a nomogram that predicts which symptoms and diseases are likely to occur in breast cancer survivors up to 15 years after diagnosis. Methods: Data from the Netherlands Cancer Registry and NIVEL Primary Care Database were combined in the Primary-Secondary Cancer Care Registry, containing data about the cancer diagnosis/treatment and data from the primary care electronic health records of 12.850 Dutch women diagnosed with breast cancer between 2000-2016. From Nivel Primary Care Database 25.700 control women without breast cancer were obtained. First, Cox regression models were built, stratified by 4 age groups and 2 time windows (1-5 and 5-15 years after diagnosis), in order to determine which symptoms and diseases were more frequently experienced in cases compared to controls (p-value&lt;.05). Second, for each significant symptom and disease, relevant treatment variables (chemo therapy (yes/no), radio therapy (yes/no, and lateralisation), hormone therapy (yes/no), axillary dissection (yes/no)) were added stepwise to the models. Variables with a p-value &lt;.10 were included in a multivariate model and all variables with a p-value &lt;.05 were retained in the final model. Findings: In total, 635 models were constructed, forming the basis for the nomogram. Late effects occurring more frequently in cases compared to controls independent of age and time since diagnosis were chest symptoms, lymphedema/arm symptoms, redness/infections of the skin, nausea, cystitis, insomnia and discussing euthanasia. Others were predominantly relevant 1-5 years after diagnosis, including vomiting and side-effects of medication. Interpretation: This nomogram can provide clinicians and women with breast cancer insight in which symptoms and diseases she has an increased risk to experience in the upcoming years, which is both applicable when making treatment decisions and at follow-up initiation. Besides, it may be a starting point to develop effective preventive measures to limit late side-effects of breast cancer and improve after care for women with breast cancer.

Citation Format: Marianne J. Heins, Kelly M. De Ligt, Janneke Verloop, Sabine Siesling, Joke C. Korevaar. Predicting symptoms and diseases after breast cancer treatment: Development of a nomogram [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-13-21.

Radiotherapy after primary CHEMotherapy (RAPCHEM): Practice variation in a Dutch registration study (BOOG 2010-03)

BACKGROUND

We conducted a prospective cohort study in the Netherlands (RAPCHEM: NCT01279304, BOOG 2010-03) in breast cancer (BC) patients treated with primary systemic therapy (PST), followed by surgery and post-operative radiation therapy (RT) according to a predefined consensus-based study-guideline (SG). The aim of the current analysis is to evaluate adherence to the SG.

METHODS

From January 2011 to January 2015, patients with cT1-2N1 BC treated in 17 Dutch RT Centres were included. Patients with four or more suspicious nodes at imaging were excluded. SG recommended whole breast RT for patients treated with breast conserving therapy. SG on loco(-regional) RT were defined for three risk groups based on the ypN status: (1) ypN0 (low-risk): RT breast and no RT after mastectomy; (2) ypN1 (intermediate-risk): RT breast or chest wall; (3) ypN2 (high-risk): RT breast or chest wall, including regional lymph nodes.

RESULTS

We included 848 patients: 292 in the low-risk group; 374 in the intermediate-risk group; 182 in the high-risk group. Overall, 64% of the patients was treated according to the SG; 11% received less RT than the predefined target volumes and 25% received more extensive RT than according to the SG. The largest variation was seen in the intermediate risk group, where only 54% was treated according to the SG.

CONCLUSION

Substantial deviation from the SG for post-operative RT was observed after PST, especially in patients with an intermediate-risk. Future analyses will evaluate outcome of these patients in relation to risk factors and the actual RT given.

Risk of cervical intra-epithelial neoplasia and invasive cancer of the cervix in DES daughters

OBJECTIVE

Women exposed to diethylstilbestrol in utero (DES) have an increased risk of clear cell adenocarcinoma (CCA) of the vagina and cervix, while their risk of non-CCA invasive cervical cancer is still unclear.

METHODS

We studied the risk of pre-cancerous (CIN) lesions and non-CCA invasive cervical cancer in a prospective cohort of 12,182 women with self-reported DES exposure followed from 2000 till 2008. We took screening behavior carefully into account. Incidence was obtained through linkage with the Netherlands Nationwide Pathology database (PALGA). General population data were also derived from PALGA.

RESULTS

The incidence of CIN1 was increased (Standardized Incidence Ratio (SIR)=2.8, 95% Confidence Interval (CI)=2.3 to 3.4), but no increased risk was observed for CIN2+ (CIN2, CIN3 or invasive cancer) compared to the screened general population (SIR=1.1, 95% CI=0.95 to1.4). Women with DES-related malformations had increased risks of both CIN1 and CIN2+ (SIR=4.1, 95%CI=3.0 to 5.3 and SIR=1.5, 95%CI=1.1 to 2.0, respectively). For CIN2+, this risk increase was largely restricted to women with malformations who were more intensively screened.

CONCLUSIONS

An increased risk of CIN1 among DES daughters was observed, especially in women with DES-related malformations, probably mainly due to screening. The risk of CIN2+ (including cancer) was not increased. However, among DES daughters with DES-related malformations a true small risk increase for non-CCA cervical cancer cannot be excluded.

Adjuvant systemic therapy in early breast cancer: impact of guideline changes and clinicopathological factors associated with nonadherence at a nation-wide level

Over recent years, adjuvant systemic treatment guidelines (AST) for early-stage breast cancer have changed considerably. We aimed to assess the impact of these guideline changes on the administration of AST in early-stage breast cancer patients and to what extent these guidelines are adhered to at a nation-wide level. We used Netherlands Cancer Registry data to describe trends in AST prescription, adherence to AST guidelines, and to identify clinicopathological determinants of nonadherence. Between 1990 and 2012, 231,648 Dutch patients were diagnosed with early breast cancer, of whom 124,472 received AST. Adjuvant endocrine treatment (ET) use increased from 23 % of patients (1990) to 56 % (2012), and chemotherapy from 11 to 44 %. In 2009-2012, 8 % of patients received ET and 3 % received chemotherapy without guideline indication. Conversely, 10-29 % of patients did not receive ET and chemotherapy, respectively, despite a guideline indication. Unfavorable clinicopathological characteristics generally decreased the chance of undertreatment and increased the chance for overtreatment. Remarkable was the increased chance of ET undertreatment in younger women (RR < 35 vs 60-69 years 1.79; 95 % CI 1.30-2.47) and in women with HER2+ disease (RR 1.64; 95 % CI 1.46-1.85). Over the years, AST guidelines expanded resulting in much more Dutch early breast cancer patients receiving AST. In the majority of cases, AST administration was guideline concordant, but the high frequency of chemotherapy undertreatment in some subgroups suggests limited AST guideline support in these patients.

[DES Daughter--expertise remains necessary]

As early as the 1950s there were warnings about the toxicity of the synthetic oestrogen diethylstilbestrol (DES), but in the Netherlands this drug continued to be prescribed to pregnant women up to the late 1970s. Until recently the periodic check-ups of children born from these pregnancies - the so-called DES Daughters - was mainly focused on genital abnormalities and the sporadically occurring clear cell adenocarcinoma of the vagina. As they grow older, the risk of this and similar types of carcinoma decreases and the nature of the periodic check-ups changes. However, check-ups cannot be omitted as the 5-yearly population study for cervical cancer is not suitable for detecting clear cell adenocarcinoma. DES Daughters should continue to receive a 2-yearly cytological check-up from their general practitioner until at least the age of 60. Now more than ever, physicians must be particularly vigilant in checking for the non-oncological late effects of DES.

Cancer risk in DES daughters

Objective

We examined long-term risk of cancer in women exposed to diethylstilbestrol (DES) in utero.

Methods

A total of 12,091 DES-exposed women in the Netherlands were followed prospectively from December 1992 till June 2008. Cancer incidence was assessed through linkage with the Dutch pathology database (PALGA) and the Netherlands Cancer Registry and compared with the Dutch female population.

Results

A total of 348 medically verified cancers occurred; median age at end of follow-up was 44.0 years. No overall increased risk of cancer was found (standardized incidence ratio [SIR] = 1.01; 95% confidence interval [CI] = 0.91, 1.13). The risk of clear cell adenocarcinoma of the vagina and cervix (CCA) was statistically significantly increased (SIR = 24.23; 95% CI = 8.89, 52.74); the elevated risk persisted above 40 years of age. The risk of melanoma diagnosed before age 40 was increased (SIR = 1.59; 95% CI = 1.08, 2.26). No excess risks were found for other sites, including breast cancer.

Conclusions

Except for an elevated risk of CCA, persisting at older ages, and an increased risk of melanoma at young ages, we found no increased risk of cancer. Longer follow-up is warranted to examine cancer risk at ages when cancer occurs more frequently.

Electronic supplementary material

The online version of this article (doi:10.1007/s10552-010-9526-5) contains supplementary material, which is available to authorized users.

[Vaginal and cervical cancer due to diethylstilbestrol (DES); end epidemic]

OBJECTIVE

To determine the current situation regarding the epidemic of clear cell adenocarcinoma of the vagina and the uterine cervix (CCAC) in relation to the exposure in utero to diethylstilbestrol (DES).

DESIGN

Descriptive.

METHODS

Patients with CCAC of the uterine cervix or vagina born after 1946 and diagnosed in the period 1969-2005, were identified through the Nationwide network and registry of histo- and cytopathology in the Netherlands and from 2003 onwards through the Netherlands Cancer Registry. Exposure data and clinical data were obtained by means of questionnaires and medical records. The histology slides of tumours were reviewed. For the patients who did not provide consent, only the date of diagnosis and age at diagnosis were known (n = 10).

RESULTS

Up to 2005, 144 CCAC patients were registered. Age at diagnosis varied from 8-54 years (mean: 28 years). In the years 1981-2000, the number of new diagnoses in 4 successive 5-year periods was fairly stable (n=26-30) but it was considerably lower in 2001-2005 (n=13). Of the patients whose history of intrauterine exposure to DES was known, 62% had been exposed (76/122). The mean age at diagnosis was 24 years for exposed patients compared to 32 years for non-exposed patients. The 10-year survival rate was 78% (95% CI: 68-87) for exposed and 69% (95% CI: 56-82) for non-exposed patients.

CONCLUSION

Since 2000, the incidence of CCAC of the vagina and cervix has decreased markedly compared to the situation in the 1980s and 1990 s. In particular, the number of patients with CCAC exposed in utero to DES has decreased. Whether this decrease shall continue over the coming years remains to be seen.

Hypospadias in sons of women exposed to diethylstilbestrol in utero: a cohort study

BACKGROUND

Transgenerational effects of diethylstilbestrol (DES) have been reported in animals, but effects in human beings are unknown. Alerted by two case reports, we aimed to establish the risk of hypospadias in the sons of women who were exposed to DES in utero.

METHODS

We did a cohort study of all sons of a Dutch cohort of 16284 women with a diagnosis of fertility problems. We used a mailed questionnaire assessing late effects of fertility treatment to identify boys with hypospadias. We compared the prevalence rate of hypospadias between boys with and without maternal DES exposure in utero.

FINDINGS

16284 mothers (response rate 67%) reported 8934 sons. The mothers of 205 boys reported DES exposure in utero. Four of these children were reported to have hypospadias. In the remaining 8729 children, only eight cases of hypospadias were reported (prevalence ratio 21.3 [95% CI 6.5-70.1]). All cases of hypospadias were medically confirmed. Maternal age or fertility treatment did not affect the risk of hypospadias. Children conceived after assisted reproductive techniques such as in-vitro fertilisation were not at increased risk of hypospadias compared with children conceived naturally (1.8, 0.6-5.7).

INTERPRETATION

Our findings suggest an increased risk of hypospadias in the sons of women exposed to DES in utero. Although the absolute risk of this anomaly is small, this transgenerational effect of DES warrants additional studies.

Physical activity and breast cancer risk in women aged 20-54 years

BACKGROUND/METHODS

Although several studies have suggested that physical activity is associated with a decreased risk of breast cancer, such a decrease has not been found consistently, perhaps because physical activity was assessed in different ways and for restricted periods. Few studies have assessed the risk of breast cancer in relation to lifetime physical activity. We used data from a population-based, case-control study, including 918 case subjects (aged 20-54 years) and 918 age-matched population control subjects, to examine associations between breast cancer risk and physical activity at ages 10-12 years and 13-15 years, lifetime recreational activity, and title of longest held job.

RESULTS

Women who were more active than their peers at ages 10-12 years had a lower risk of breast cancer (odds ratio [OR] = 0.68; 95% confidence interval [CI] = 0.49-0.94). Women who had ever engaged in recreational physical activity had a reduced risk of breast cancer compared with inactive women (OR = 0.70; 95% CI = 0.56-0.88). Neither very early recreational activity (before age 20 years) nor recent activity (last 5 years) was associated with a greater reduction in risk than recreational activity in the intermediate period. Furthermore, women who started recreational activities after age 20 years and women who started earlier and continued their activities throughout adult life experienced a similar reduction in risk. Lean women, i.e., women with a body mass index (weight in kg/[height in m](2)) less than 21. 8 kg/m(2), appeared to have a lower risk associated with recreational physical activity than women with a body mass index greater than 24.5 kg/m(2) (OR = 0.57 [95% CI = 0.40-0.82] and OR = 0. 92 [95% CI = 0.65-1.29], respectively).

CONCLUSIONS

Our findings support the hypothesis that recreational physical activity is associated with a decreased risk of breast cancer. Physical activity in early or recent life does not appear to be associated with additional beneficial effects.