Breast Cancer During Pregnancy Research Articles

Clinicopathologic features, treatment, and prognosis of pregnancy-associated breast cancer.

To identify the clinicopathological features, treatment, and prognosis of patients with breast cancer, who were diagnosed during and after pregnancy. We searched for patients with pregnancy-associated breast cancer (PABC) using the big data query and analysis system of Peking Union Medical College Hospital from between January 1, 2013, and December 31, 2021, and matched each patient with two non-PABC patients by age at diagnosis, year at diagnosis, and tumor stage. The clinicopathologic features, treatment, and outcomes of breast cancer during pregnancy (BC-P) and breast cancer during the first-year post-partum (BC-PP) were examined retrospectively in two case-control studies. Eighteen BC-P cases, 36 controls for BC-P cases, 62 BC-PP cases, and 124 controls for BC-PP cases were enrolled in our study. The expression of HER-2 and Ki-67 was higher in BC-PP cases than in its controls (P=0.01, 0.018, respectively). Patients with BC-PP were more likely to choose mastectomy than breast-conserving surgery (P=0.001). There were no significant differences in event-free survival (EFS) between patients with BC-P and BC-PP and their controls. BC-P and BC-PP patients displayed adverse clinicopathological features in our population. However, when matched by age at diagnosis, year of diagnosis, and tumor stage, BC-P and BC-PP patients did not show inferior outcomes to controls, probably due to aggressive multimodality therapy.

Outcome of breast cancer patients treated with chemotherapy during pregnancy compared with non-pregnant controls.

515 Background: Overall a diagnosis of breast cancer during pregnancy (BCP) appears not to impact maternal prognosis if standard treatment is offered. However, caution is warranted as gestational changes in pharmacokinetics with respect to the distribution, metabolism and excretion of drugs may lead to reduced chemotherapy concentration in pregnant patients. This cohort study was designed to focus on the maternal prognosis of BCP patients that receive chemotherapy during pregnancy. Methods: The outcome of BCP patients treated with chemotherapy during pregnancy was compared to non-pregnant breast cancer patients treated with chemotherapy, diagnosed after 2000, excluding postpartum diagnosis and with an age limit of 45 years. The data was registered by two multicentric registries (the International Network of Cancer, Infertility and Pregnancy and the German Breast Cancer Group) that collect both retro-and prospectively breast cancer data. Cox proportional hazards regression was used to compare disease-free (DFS) and overall survival (OS) between both groups, adjusting for age, stage, grade, hormone receptor status, human epidermal growth factor 2 status and histology, weighted by propensity scoring in order to account for the differences in baseline characteristics between pregnant patients and controls. Results: In total, 662 pregnant and 2081 non-pregnant patients, were eligible for analysis. Median age at diagnosis was 34 (range 22-47) years for pregnant and 38 (range 19-45) years for non-pregnant patients. Pregnant patients were more likely to have stage II breast cancer (60.1% vs 56.1%, p = 0.035), grade 3 tumors (74.0% vs 62.2%, p < 0.001), hormone receptor-negative tumors (48.4% vs 34.0%, p < 0.001) or triple-negative breast cancer (38.9% vs 26.9%, p < 0.001). Median follow-up was 66 months. DFS and OS were comparable for pregnant and non-pregnant patients (DFS: HR 1.02, 95%CI 0.82-1.27, p = 0.83; OS: HR 1.08, 95% CI 0.81-1.45, p = 0.59). A subgroup analysis of 339 women that received more than 60% of chemotherapy during pregnancy (cut-off at median) revealed a comparable survival compared to non-pregnant women (DFS: HR 0.81, 95%CI 0.62-1.06, p = 0.13; OS: HR 0.85 95% CI 0.58-1.23, p = 0.39). Conclusions: Pregnancy-induced alternations in chemotherapy concentration do not seem to affect maternal prognosis in breast cancer patients. These results support initiation of chemotherapy for BCP where indicated for oncological reasons.

Prognosis, biological characteristics and importance of treatment's delay of breast cancer diagnosed during pregnancy.

e12545 Background: Breast cancer in pregnancy is that diagnosed during pregnancy or in the first year after birth (1), is the most frequent malignant neoplasms during pregnancy, (2,3); however, only 0.2% to 2.9% of all breast cancers occur during pregnancy(4), the incidence of breast cancer during pregnancy (BCDP) has increased the last few decades probably because of the delayed childbearing and the rise of maternal age (5,6). Because of the rarity of cases and the impracticability of conducting randomized controlled studies in this setting, several studies are retrospective, whilst some studies suggest outcomes for women are similar to non-pregnant patients with breast cancer(8–11), others (12–17) have demonstrated that pregnancy in itself is an adverse prognostic factor for survival. To contribute with the existing literature, we aimed to perform a cohort to analyze if there is a difference prognosis of patients with BCDP who started treatment during pregnancy or waited for delivery. Methods: We analyzed the baseline characteristics distribution in the BCP using the chi-square test and the Fisher’s exact test for categorical variables. We considered a statistically significant association when p value was < 0.05. DFS and OS analyses were conducted using the Kaplan–Meier method, and the log-rank test was used to determine if there were any differences in the survival curves by the variables of interest. We performed the statistical analysis using the SPSS 25.0 software for Windows (SPSS Inc., Chicago, IL, USA). Results: Among 8037 breast cancer patients enrolled in the database at Instituto Nacional de Cancerología, Mexico (INCan), within the social security program named “Seguro Popular”, between January 2007 and June 2018, we identified and included 61 women, median maternal age at diagnosis in our BCP group was 35 years (range 21-47), triple negative and her2 comprised 50.8% and 49.2% of BCP is comprised by luminal tumors. Conclusions: We strongly believe that the treatment of breast cancer during pregnancy should be started as soon as possible, since we have seen that its delay in childbirth translates into worse disease-free and overall survival. [Table: see text][Table: see text]

Clinico-pathologic features, treatment and outcomes of breast cancer during pregnancy or the post-partum period.

Breast cancer during pregnancy (BC-P) or the first year post-partum (BC-PP) is rare and whether it differs from breast cancer (BC) in young women not associated with pregnancy is uncertain. We queried our institutional database for BC-P and BC-PP cases and matched controls with BC not associated with pregnancy diagnosed between January 1, 1985 and December 31, 2013. We performed two parallel retrospective cohort studies evaluating clinico-pathologic features, treatment and outcomes for BC-P and BC-PP cases compared to their controls. In our population of 65 BC-P cases, 135 controls for BC-P cases, 75 BC-PP cases and 145 controls for BC-PP cases, high grade and estrogen receptor-negativity were more frequent in both case groups than their controls. Among those with stage I-III BC, patterns of local therapy were similar for both case groups and their controls, with the majority undergoing surgery and radiation. Over three-fourths of those with stage I-III BC received chemotherapy. BC-P cases tolerated chemotherapy well, with the majority receiving doxorubicin/cyclophosphamide every 3weeks. On multivariate analyses of those with stage I-III BC, BC-P cases had non-significantly higher hazards of recurrence and death compared to their controls, while BC-PP cases had non-significantly lower hazards of recurrence and death compared to their controls. BC-P and BC-PP were associated with adverse clinic-pathologic features in our population. However, we did not observe inferior outcomes for BC-P or BC-PP compared to controls, likely due to receipt of aggressive multi-modality therapy.

Biology, staging, and treatment of breast cancer during pregnancy: reassessing the evidences.

Breast cancer is one of the most frequently diagnosed malignancies during pregnancy. Here, we review the management of women with breast cancer during pregnancy (BCP), focusing on biology, diagnosis and staging, local and systemic treatments, obstetric care and long-term follow-up of children with prenatal exposure to anticancer treatments.

Study on the adverse effects following chemotherapy for breast cancer diagnosis during pregnancy

Rationale:Treatment of breast cancer during pregnancy (BCP) remains a challenge to physicians. Surgery and chemotherapy during pregnancy are widely used for the treatment of BCP. Herein, we reported 3 Chinese patients with BCP who underwent chemotherapy during pregnancy and were followed up for adverse effects.Patient concerns:Three female patients (case 1, case 2, and case 3) of 37-, 32-, and 28-year-old with breast masses were enrolled. Case 1 had been pregnant for over 4 months, case 2 over 7 months, and case 3 for 7 months. Ultrasound findings revealed a mass in the left breast in cases 1 and 2 (30 mm × 26 mm × 23 mm and 34 mm × 16 mm × 40 mm), and case 3 had 2 masses in the outer upper quadrant of right breast (27 mm × 27 mm × 26 mm, 18 mm × 17 mm × 17 mm) and 2 fixed enlarged lymph nodes in the right axillary fossa, respectively.Diagnoses:All breast masses were diagnosed by core needle biopsy, and the result was infiltrating ductal carcinoma.Interventions:Chemotherapy regimen administered during pregnancy was EwP (epirubicin 80 mg/m2, d1 + paclitaxel 80 mg/m2, d1, 8, 15, and cycled every 21 days). During pregnancy, case 1 received 5 cycles, case 2 received 1 cycle, and case 3 received 2 cycles.Outcomes:Case 2 patient experienced grade III bone marrow suppression once. Electrocardiogram (ECG) result of case 3 showed occasional occurrence of ventricular premature beats, with no complaint of discomfort. All 3 patients experienced uterine contractions, which caused preterm labor in case 2. Adverse events were nausea, hair loss, acid reflux, and constipation. Neonatal jaundice occurred in the premature infant (case 2), which was resolved by phototherapy. No relapse or metastasis was observed in the 3 cases and the infants are growing normally.Lessons:Both patients and infants well tolerated the combination chemotherapy of epirubicin and paclitaxel during pregnancy. There were few drug toxicities and adverse effects.

Multidisciplinary Management of Breast Cancer During Pregnancy.

Although breast cancer during pregnancy (BCDP) is rare (occurring with only 0.4% of all BC diagnoses in female patients aged 16-49 years), management decisions are challenging to both the patient and the multidisciplinary team. Experts in breast cancer at the University of North Carolina conducted a targeted literature search regarding the multidisciplinary treatment approaches to BCDP: medical, surgical, and radiation oncology. Supportive care, including antiemetic agents, and imaging approaches were also reviewed. Review of the literature revealed key points in the management of BCDP. Surgical management is similar to that in nonpregnant patients; pregnant patients may safely undergo breast-conserving surgery. Recommendations should be tailored to the individual according to the clinical stage, tumor biology, genetic status, gestational age, and personal preferences. Anthracycline-based chemotherapy can be safely initiated only in the second and third trimesters. The rate of congenital abnormalities in children exposed to chemotherapy is similar to the national average (approximately 3%). Dosing of chemotherapy should be similar to that in the nonpregnant patient (i.e., actual body surface area). Antihuman epidermal growth factor receptor 2 therapy, radiation, and endocrine treatment are contraindicated in pregnancy and lactation. Care should include partnership with obstetricians. The literature regarding prognosis of BCDP is mixed. To maximize benefit and minimize risk to the mother and fetus, an informed discussion with the patient and her medical team should result in an individualized treatment plan, taking into account the timing of the pregnancy and the stage and subtype of the breast cancer. Because BCDP is rare, it is essential to collect patient data in international registries. The Oncologist 2017;22:324-334 IMPLICATIONS FOR PRACTICE: Breast cancer during pregnancy is a major ethical and professional challenge for both the patient and the multidisciplinary treatment team. Although the oncologic care is based on that of the non-pregnant breast cancer patient, there are many challenges from regarding the medical, surgical and radiation oncology and obstetrical aspects of care that need to be considered to deliver the safest and best treatment plan to both the mother and developing fetus.

Abstract P2-03-09: Comparison of the mutational landscape of breast cancer during pregnancy and non-pregnant controls

Abstract Background:Currently, breast cancer during pregnancy (BCP) is not believed to be biologically different from breast cancer unrelated to pregnancy based on limited datasets mainly obtained by immunohistochemistry. However, some groups report that BCP patients have an inferior survival compared to young non-pregnant breast cancer patients. The largest analysis based on the BCP registry by the German Breast Group (GBG) revealed however, no difference between pregnant and non-pregnant breast cancer patients, indicating that treatment rather than biology might be the reason for the inferior survival reported by others. Methods: The BCP study (GBG 29/BIG 03-02) is a multicentre observational study for breast cancer during pregnancy. In tumour tissue collected within this study from pregnant M0 patients we investigated the following genes: AKT1, ATM, BRAF, CBFB, CCND1, CDH1, CDKN2A, CTCF, EGFR, ERBB2, ESR1, FGFR2, GATA3, KRAS, MAP2K4, MAP3K1, MDM2, MED12, MYC, PIK3CA, PIK3R1, PTEN, RB1, RUNX1, and TP53 by massive parallel sequencing (MPS). This included patients with all molecular subtypes: HR+/-, HER2+/-. Sequencing was done on an IonTorrent Proton using a custom designed Breast Cancer Panel (BCPv2). This panel comprises 236 amplicons split into two primer pools and covers hotspot regions of 138 exons of the 25 genes. To test the hypothesis that breast cancer diagnosed during pregnancy is biologically not different from breast cancer diagnosed in young non-pregnant women, we compared the molecular profiles obtained, with genetic data from M0 patients not known to be pregnant from TCGA with age <= 45. TCGA data were pre-processed to be compatible to the targeted MPS datasets from pregnant patient. Results: Material from 141 patients from the BCP study was available from which ultimately 109 fully evaluable MPS datasets could be obtained. In the TCGA data set 114 breast cancer patients <= 45 years could be identified. Pregnant patients with breast cancer were significantly younger, had more often HR- tumours (59.6% vs 30.1%) but had less frequently grade 3 tumours (30.6% vs 48.2%). All other clinical variables showed no significant differences between pregnant and non-pregnant patients. In the BCP data, overall 106 mutations could be found. The most frequent mutations were detected in TP53 (62%) and in PIK3CA (11.1%). In non-pregnant patients the mutation rates were different with 32.5% in TP53 and 21.1% in PIK3CA. Exact matching by variables age, HR, HER2 and grade yielded 40 patients from both datasets. In these subcohorts, still divergent mutational rates for TP53 and PIK3CA between pregnant and non-pregnant women were noted, however, the differences failed to reach statistical significance. Conclusions: Overall the mutational landscapes do not seem to be overtly different between pregnant patients and no-pregnant controls, although slight imbalances in mutational rates occurred, which might be partly explained by a selection bias and a small sample size after matching. Further comparisons using other datasets, looking into survival and regarding copy number variation are currently conducted. This research is been funded by the German Cancer Consortium-DKTK and the BANSS Foundation. Citation Format: Loibl S, Pfarr N, Weber K, Neunhöffer T, Villegas S, Stenzinger A, Furlanetto J, Aktas B, Budczies J, Marmé F, Kahmann L, Denkert C, Weichert W. Comparison of the mutational landscape of breast cancer during pregnancy and non-pregnant controls [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-03-09.

Abstract P1-07-02: 5-year overall survival of early breast cancer during pregnancy: A multicenter French case control study

Abstract Background: Breast cancer (BC) during pregnancy (BCP) is a rare situation that requires collaboration between oncologists, surgeons and obstetricians. The main objectives of this study were to compare the overall survival (OS) and disease free survival (DFS) of a multicenter cohort of pregnant patients (pts) with those of matched control pts. Methods: Patients from 27 centers and diagnosed between 2000 and 2006 with histological confirmed M0 invasive BC were included in this retrospective study. For the cohort of BCP, pts whose pregnancy was interrupted were not eligible. Controls were matched to BCP pts on 5 criteria: clinical T (of TNM), hormonal receptor (HR) status, HER2 status, administration of neo-adjuvant chemotherapy and pathological nodal status in the absence of neo-adjuvant chemotherapy. Survival times were estimated from the date of diagnosis using Kaplan-Meier method. OS was calculated until death from every cause, DFS was calculated until relapse or death from every cause; patients alive were censored at the date of last news. Results: 100 BCP pts were identified. Their clinical and pathological characteristics were described on a previous presentation (SABCS 2013 P6-06-07). Matched controls could not be found for 12 BCP pts. 88 BCP pts were matched with 204 controls. The only differences between the 2 populations in terms of characteristics or treatment were more radical mastectomy (p=0.036) and fewer taxane administrations in the BCP group (p=0.06). The median duration of follow-up was 8.2 years for cases and 7.7 years for controls. There were no differences between BCP pts and controls in 5-year OS: 83.4%, IC 95% (73.5-89.8) vs 83.8%, IC 95% (77.9-88.3) nor 7-year OS: 76.5% (65.5-84.4) vs 78.1% (71.5-83.3) (p=0.52). The 5-year DFS was 58.6% IC 95% (47.3-68.3) vs 67.2% IC 95% (60.2-73.2) (p= 0.16). However, 5-year DFS was lower in HR+ BCP pts subgroup than in HR+ control group (56.7% IC 95% (40.7-69.8) vs 70.9% IC 95% (61.4-78.5) (p=0.023). Conclusion: This multicenter French large study confirmed that there are no differences on OS and DFS between pregnant and no pregnant pts, though this might not be true for HR subgroup. Citation Format: Vanlemmens L, Ploquin A, Delaloge S, Rouzier R, Lesur A, Frenel J-S, Loustalot C, Bachelot T, Provansal M, Ferrero J-M, Coussy F, Debled M, Kerbrat P, Vinceneux A, Djelila A, Baron M, Jebert S, Decoupigny E, Tresch E, Bonneterre J. 5-year overall survival of early breast cancer during pregnancy: A multicenter French case control study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-07-02.

Breast Cancer Diagnosed During Pregnancy: Adapting Recent Advances in Breast Cancer Care for Pregnant Patients.

Breast cancer during pregnancy (BCP), although rare, is becoming more common and treatment should be as similar as possible to that for nonpregnant young patients with breast cancer. A group of specialists convened to review current guidelines and provide guidance on how recent advances in breast cancer diagnosis and treatment can be adapted for pregnant patients. The majority of patients with BCP will be considered for treatment during the pregnancy. Premature delivery should be avoided whenever possible. Most treatments, including sentinel lymph node biopsy, systemic therapy with taxanes, platinum agents, or dose-dense treatment can be safely given during pregnancy, after careful risk/benefit assessment for mother and child. Chemotherapy is contraindicated during the first trimester because of a higher risk of fetal malformations but is feasible in the second and third trimesters. Other treatments such as radiation therapy or anti-human epidermal growth receptor 2 treatment are in general not indicated during pregnancy but might be considered in some instances. Patient data should be collected in a systematic way whenever possible.

Neoadjuvant chemotherapy for patients with breast cancer during pregnancy (BCP).

1071 Background: Neoadjuvant therapy (NAT) is increasingly considered the treatment of choice for patients with HER2+ and triple-negative (TNBC) breast cancer. It is recommended to treat patients w...

Abstract P6-06-07: 5-year disease free-survival results of aggressively-treated breast cancer during pregnancy: Results from a French multicenter study

Abstract Background: Breast cancer (BC) during pregnancy (BCP) is a rare situation that requires multi-disciplinary management. The objectives of this study were to assess the tumor characteristics, clinical course and outcome of such patients (pts). Methods: French hospitals were invited to collect retrospective clinical, treatment and follow-up data of BCP managed between 2000 and 2006. Pts with histologically confirmed M0, invasive BC and pregnant at diagnosis were included. Pts whose pregnancy was interrupted were not eligible. Survival times were calculated from the date of diagnosis. Results: 100 BCP pts were identified. Median age was 32 years (24-42). Median gestational age at diagnosis was 25 weeks (3-38). 84% and 13% had palpable breast axillary mass respectively. Clinical stages were 1T0, 21T1, 39T2, 28T3, 6 T4A-C, 2 T4D, 3 TX, 56 N0, 39 N1, 5 NX. Histological analysis identified 85 ductal carcinomas, 4 lobular, 11 others. The histopathological grades was G1 in 4,3%, G2 in 29%, and G3 in 66,7%. Tumor subtype was luminal A in 3%, luminal B in 37% (24HER2-, 13HER2+), luminal undetermined in 6%, triple-negative in 45,9%, Her2 + in 21,3%, and not classified in 2% (HR -, HER 2 unknown). Median time interval between first observation and biopsy was 31 days (0-337), respectively 40 days (0-337) and 15 days (0-172) when the first observation was made by patients or physicians. Median time interval between pathologic diagnosis and treatment was 18 days (0-295). Treatment was initiated after pregnancy for 42 pts, with median time of 18 days after delivery. 97 pts received chemotherapy with a median number of 6 cycles (4-11), 92 with anthracyclin, 44 with taxanes. 53 chemotherapy were administered in neo adjuvant setting among which 25 during pregnancy), and 44 in adjuvant setting (23 during pregnancy). 98 pts underwent surgery (34 during pregnancy), with 57 conservations and 41 mastectomies, 93 pts received radiotherapy and 43 hormone therapy after pregnancy. 10 pts received Trastuzumab. The mean gestational age at delivery was 35 weeks (22-45). All children were alive, with a median weight of 2735 g at birth (550-3740). The 5-year Overall Survival rate is 83% (95%CI 74-89), while Disease Free Survival is 53% (95%CI 43-63). First recurrence site was metastasis in 28, locoregional in 13, controlateral in 9 and other cancers in 2. Conclusion: Biopsy and treatment intervals remain long among this population. In this large series BCP, there is an excess of triple-negative breast cancer. The 5-year OS rate is higher than previously reported but with DFS is lower. BCP remains an aggressive entity despite adapted treatment. Multivariate analysis will be presented. A comparison of this BCP population to matched controls is ongoing. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-06-07.

Trastuzumab, lapatinib and bevacizumab during pregnancy

5 ISSN 1758-1923 10.2217/BMT.12.51 © 2013 Future Medicine Ltd Breast Cancer Manage. (2013) 2(1), 5–7 Breast cancer is one of the most common types of cancer in women of reproductive age and, thus, also one of the most often encountered types of cancer diagnosed during pregnancy. The estimated incidence varies from one in 3000 to one in 10,000 deliveries annually, depending on the study population used. As women postpone childbearing to a later age, the chance of developing a malignancy during pregnancy rises, and increasing incidence has recently been reported in two populationbased cohort studies from Sweden and Australia [1,2]. Historically, breast cancer during pregnancy (BCP) was viewed as a particularly aggressive and incurable type of cancer. However, as research has evolved, and oncologic treatment is more commonly applied during pregnancy, prognosis of BCP has also improved and is now comparable with prognosis of the nonpregnant patient [3]. We have advocated that treatment during pregnancy should be according to the standard as much as possible [4]. Based on available cohort studies, surgery and also chemotherapy (from 12–14 weeks gestation) is possible during pregnancy without impairment of fetal safety [5]. It is unclear whether or not a higher incidence of HER2 overexpression occurs in BCP when compared with nonpregnant controls [3]. Targeted therapy (e.g., trastuzumab, lapatinib and bevacizumab) has not been thoroughly investigated during pregnancy and clinical experience is very limited. The majority of targeted agents inhibit normal growth factors or angiogenesis, which might be harmful for the growth and development of the fetus. Trastuzumab is an IgG monoclonal antibody used for treating breast cancer overexpressing the HER2 receptor (~20–30% of all breast cancers), and is a member of the human EGF receptor (EGFR) family. Its use in the adjuvant setting is associated with significant improvement of survival [6,7]. Transplacental transport of trastuzumab to the fetus is comparable with transport of other IgG antibodies. IgG antibodies require active transport across the placental barrier and most of the IgG in a fetus is of maternal origin. Fetal IgG levels are very low in the first trimester; transport increases with gestational age and typically exceeds maternal IgG concentrations at full-term pregnancy [8]. Transplacental transport of trastuzumab in a pregnant baboon model showed similar

Abstract P6-07-05: Prognosis of 368 women with primary breast cancer during pregnancy: results from an international collaborative trial

Abstract Objective: We aimed to add to the limited outcome data on breast cancer during pregnancy (BCP), and compared disease-free survival (DFS), and overall survival (OS) between patients with BCP and breast cancer not diagnosed during pregnancy, adjusted for known prognostic factors. Methods: We analyzed a pro- and retrospectively compiled multi-centric registry of BCP patients (www.cancerinpregnancy.org and GBG/BIG 0203). Outcome was compared to a control group of patients who did not have associated pregnancies. The main analysis is a Cox proportional hazards regression of disease free survival (DFS) and overall survival (OS) on exposure (pregnant or not). The analysis was weighted by propensity score matching to correct for any bias that may have been associated with differences in baseline characteristics, with the following set of covariates: age, stage, grade, hormone receptor status, HER2 status, histology, type of chemotherapy and trastuzumab. Sensitivity analysis was also performed on age only, and also on chemotherapy only. Results: From April 2003-December 2011, 447 women with BCP were registered, 368 women with BCP were eligible for this analysis. The control group consisited of 2739 women (ratio 1:7.44). Median age was 33 years (interquartile range 30–36) for the cases and 41 years (interquartile range 37–43) for the controls. Median follow-up was 57 months. There were no statistically significant differences noted for DFS and OS studied after propensity-score matching, and sensitivity analysis. Conclusion: Patients diagnosed with breast cancer during pregnancy do not have a worse prognosis compared to patients who are not pregnant after matching for prognostic factors and treatment. This information is important when BCP patients are counseled regarding prognosis and adds to the possibility of treatment during pregnancy. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-05.

The biological features and prognosis of breast cancer diagnosed during pregnancy: A case-control study

Background. Breast cancer during pregnancy (BCP) is relatively rare and is associated with controversies about its biology and prognosis. Hence, we designed a case-control study to examine tumor features and outcome in a series of BCP patients diagnosed and treated in a single institution. Material and methods. We identified 65 patients diagnosed with BCP and for each; we selected two non-pregnant breast cancer patients, who were matched for age, year of surgery, stage, and neoadjuvant chemotherapy. We then compared the differences in pathology, immunohistochemical features (ER, PR, HER2 and ki-67), disease-free (DFS) and overall survival (OS). Results. We did not find any significant differences in tumor characteristics between the two groups. However, at a median follow-up of four years, BCP patients had an inferior DFS (HR 2.3; 95% CI 1.3–4.2), after adjustment for possible confounding covariates. No difference in OS was observed. However, upon restricting the analysis to patients who did not receive neoadjuvant chemotherapy, patients with BCP had inferior OS as well (HR 2.6; 95% CI 1.0–6.5). No association between induction of abortion and prognosis was observed. Conclusions. While we did not observe any differences in tumor features, BCP patients have poorer prognosis compared to age and stage-matched control. Further studies should try to elucidate reasons for such poor outcome.

Breast cancer diagnosed during pregnancy and lactation: biological features and treatment options

Assessment of biological features and treatment of patients with breast cancer presenting during pregnancy or lactation. Immunohistochemical analysis of estrogen receptor (ER) and progesterone receptor (PgR), Ki-67, HER2/neu, prognostic markers, treatment and follow-up of 21 patients with breast cancer during pregnancy (BCdP) and 17 with breast cancer during lactation (BCdL) are presented. Median age was 36 and 33 years, median tumour size was 2.4 and 2.5 cm, axillary lymph nodes were positive in 10 of 21 pregnant patients and 11 of 17 lactating patients, respectively. Both ER and PgR were not expressed in six of 21 pregnant women and nine of 17 lactating patients. All the six women who had concurrent diagnosis of breast cancer and pregnancy (first trimester) preferred termination of pregnancy although an alternative option was discussed. Five patients received anthracycline containing chemotherapy during the second and third trimester with no complications for patient and child. Conservative surgery was performed in 15 of 21 patients during pregnancy with no local reappearance after a median follow-up of 24 months. Three pregnant women underwent lymphoscintigraphy and sentinel lymph node biopsy. Patients who had concurrent diagnosis of breast cancer and pregnancy (early first trimester) preferred termination of pregnancy to allow easier completion of treatment. Conservative surgery was safe also in women with BCdP. Sentinel node biopsy might be considered for pregnant patients with a clinically negative axilla.