The effect of attendance in the Dutch breast cancer screening program on breast tumor characteristics among migrant women

BACKGROUND

In general, migrant women have a lower breast cancer (BC) incidence rate and higher BC mortality than autochthonous women. Further, migrant women show lower participation in the national BC screening program. To further investigate those aspects, we aimed to determine differences in incidence and tumor characteristics between autochthonous and migrant BC patients in Rotterdam, the Netherlands.

METHODS

We selected women diagnosed with BC in Rotterdam during 2012-2015 from the Netherlands Cancer Registry. Incidence rates were calculated by migrant status (i.e., women with or without migration background). Multivariable analyses revealed adjusted odds ratios (OR) and 95% confidence intervals (CI) on the association between migration status and patient and tumor characteristics, additionally stratified by screening attendance (yes/no).

RESULTS

In total 1372 autochthonous and 450 migrant BC patients were included for analysis. BC incidence was lower among migrants than among autochthonous women. Overall, migrant women were younger at BC diagnosis (53 vs. 64 years, p < 0.001), and had higher risks of positive lymph nodes (OR 1.76, 95% CI 1.33-2.33) and high grade tumors (OR 1.35, 95% CI 1.04-1.75). Especially non-screened migrant women had higher risk of positive nodes (OR 2.73, 95% CI 1.43-5.21). Among the subgroup of screened women, we observed no significant differences between migrant and autochthonous patients.

CONCLUSION

Migrant women have lower BC incidence than autochthonous women, but diagnosis was more often at younger age and with unfavorable tumor characteristics. Attending the screening program strongly reduces the latter. Therefore, promotion of participation in the screening program is recommended.

Abstract P1-09-04: Association between a breast cancer polygenic risk score and contralateral breast cancer risk

Background

Breast cancer patients are at significant risk of a second contralateral, breast cancer (CBC). Identification of women at high or low CBC risk could improve patient management decisions. Previous research has shown that breast cancer-associated single nucleotide polymorphisms (SNPs) summarized in a polygenic risk score (PRS) predict the risk of a first breast cancer with an odds ratio (OR) per 1 SD of 1.55 (95% confidence interval (95%CI)=1.52-1.58) (77-SNP PRS). The aim of this study was to evaluate the association between a recently developed PRS and CBC risk.

Methods

We identified 19 studies from the Breast Cancer Association Consortium (BCAC) with follow-up information on participating patients and at least 10 patients diagnosed with CBC. This included 38,228 females of European ancestry diagnosed with first invasive breast cancer since 1990. Genotyping was done using the iCOGS array or OncoArray, with genotypes for SNPs not on the arrays estimated by imputation. We used a 313-SNP PRS, optimized for prediction of overall (first) breast cancer in the BCAC dataset. Metachronous CBC risk by PRS was quantified using univariable and multivariable Cox regression analyses stratified by country and adjusted for multiple patient, tumor, and treatment characteristics. We assessed PRS interaction with age, family history, adjuvant systemic therapy, and ER-status.

Results

Median time to develop a CBC (N=1,046) after a first breast cancer was 5.8 years (range 0.3-21.9). Higher PRS was associated with increased CBC risk: hazard ratio (HR) per 1 SD=1.31 (95%CI=1.23-1.39). Patients in the highest and lowest 5% of the PRS had 1.95 fold and 0.67 fold risks of CBC, respectively, compared with patients in the middle quintile. Adjustments for age, year of diagnosis, family history, tumor size, nodal status, ER-status, or treatment (chemotherapy, endocrine therapy, radiotherapy) did not substantially alter these results. We found an interaction with age at first breast cancer diagnosis (Pinteraction=.002); the PRS was associated with an increased CBC risk for patients aged ≥40 years (HR=1.37, 95%CI=1.28-1.47), but not for patients &lt;40 years (HR=1.06, 95%CI=0.93-1.21).

Conclusion

The PRS is predictive for the development of CBC in patients ≥40 years at first breast cancer diagnosis. For this group, the PRS could be incorporated in CBC risk prediction models to help define high and low risk patients, and hence optimize screening and treatment strategies.

Citation Format: Kramer I, Hooning MJ, Breast Cancer Association Consortium (BCAC), Mavaddat N, Canisius S, Keeman R, van den Broek AJ, Steyerberg E, Hauptmann M, Pharoah PD, Easton DF, Hall P, Schmidt MK. Association between a breast cancer polygenic risk score and contralateral breast cancer risk [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-04.

Abstract P4-09-07: Higher risk of metachronous contralateral breast cancer in patients with invasive lobular breast cancer

Background: Risk of metachronous contralateral breast cancer (CBC) is an important health issue in primary breast cancer (PBC) survivors. Individualized CBC risk prediction can help identify patients at high or low risk who may or may not benefit from additional surveillance and treatment. For lobular PBC, inconsistent results have been reported on an association with increased risk of CBC. We investigated CBC risk in lobular versus ductal PBC using a large nationwide dataset and taking into account age at PBC and (neo-)adjuvant systemic therapy effects.

Patients and Methods: We selected women diagnosed between 2003 and 2010 with early invasive lobular, lobular mixed with other types, or ductal PBC from the Netherlands Cancer Registry. Categorical and continuous characteristics between the 3 groups were compared using the chi-square statistics and the Kruskal-Wallis test, respectively. Competing risk analyses were applied to determine CBC incidence. Multivariable subdistribution hazard ratios (SHRs) were adjusted for primary tumor stage, age at PBC diagnosis, radiotherapy, (neo-)adjuvant chemotherapy and endocrine therapy.

Results: We selected 74,373 women aged &gt;18 years with lobular (n=8,903), lobular mixed (n=3,512), and ductal (n=62,230) PBC. Women with lobular PBC were older at diagnosis than women with lobular mixed or ductal PBC (61 vs. 58 vs. 58 years, respectively), more often had ER-positive PBC (95.7% vs. 94.1% vs. 79.6%) and were more often systemically treated with only endocrine therapy (30.7% vs. 24.9% vs. 19.7%), while less often treated with only chemotherapy (4.2% vs. 5.3% vs. 15.4%).

Ten-year cumulative CBC incidences in women with lobular, lobular mixed or ductal PBC were 3.2%, 3.6% and 2.8% when treated with systemic therapy (chemotherapy and/or endocrine therapy) and 6.6%, 7.7% and 5.6% without systemic therapy, respectively. Multivariable SHRs were 1.19 (95% CI: 1.05-1.34) for lobular and 1.39 (95% CI: 1.17-1.65) for lobular mixed versus ductal PBC; for women &lt;50 years, risk differences were larger: 1.60 (95% CI: 1.26-2.05) and 1.43 (95% CI: 1.00-2.06), respectively.

Conclusion: Lobular histology and lobular mixed histology are independent risk factors for CBC development, and should be considered as prognostic factors when refining CBC risk prediction models.

Citation Format: Akdeniz D, Kramer I, van Deurzen CH, Schaapveld M, Westenend PJ, Voogd AC, Jager A, Steyerberg EW, Sleijfer S, Schmidt MK, Hooning MJ. Higher risk of metachronous contralateral breast cancer in patients with invasive lobular breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-09-07.

Abstract P6-13-01: MRI breast cancer screening compared to mammography in women with a familial risk: A multicenter randomized controlled trial

Background: Screening guidelines for women with a family history of breast cancer without a known causative gene mutation differ per country. No randomized controlled trial has been performed to assess the optimal screening strategy for these women.

Methods: In twelve centers, 1355 women aged 30–55 years with a cumulative lifetime risk of ≥20% without a BRCA1/2 mutation were randomized into two arms. From January 2011 until December 2017, women in the MRI-arm received yearly MRI-screening, clinical breast examination (CBE), and mammography every other year; and in the Mx-arm yearly mammography and CBE. Outcomes were number and stage of detected breast cancers, sensitivity, specificity and positive predictive value, and stratified by screening round and by mammographic density.

Results: After on average 4.3 screening rounds per woman, in the MRI-arm (N=675) compared to the Mx-arm (N=680) more breast cancers were detected (41 versus 14, p&lt;0.001), invasive cancers were smaller (median size 8 versus 17 mm, p=0.006) and less often node positive (20% versus 71.4%, p=0.019)(Table). In the MRI-arm, sensitivity was slightly higher (95.1% versus 92.9%, p=1), and specificity significantly lower (82% versus 90.1%, p&lt;0.001), compared to the Mx-arm. After two rounds, specificity improved for both modalities (87.1% for MRI; 93.0% for Mx; p&lt;0.001) and no ≥T2 tumors or interval cancers occurred in the MRI-arm. All tumors ≥T2 were in the two highest density categories. MRI detected more small invasive tumors than Mx across all density categories.

Conclusions: In real-life practice the MRI-arm detected more, relevantly smaller, and far more often node negative tumors, and also at low density in women with a familial risk for breast cancer.

Table 1Characteristics of participating women at baseline and of the detected breast cancers, according to study armParticipantsMRI-arm n=675Mx-arm n=680MRI-arm vs. Mx-arm p-valueMean age yr ± SD44.6 ± 6.244.7 ± 6.3 Premenopausal512 (76%)505 (74%) Previous Mx ≤ 2 yr536 (79 %)542 (80%) Previous Mx &gt; 2 years ago23 ( 3%)29 ( 4%) Previous MRI ≤ 2 years ago62 ( 9%)81 (12%) Previous MRI &gt; 2 years ago91 (14%)89 (13%) BI-RADS density category*   I (entirely fat)88 (13%)92 (14%) II (scattered densities)248 (37%)229 (34%) III (heterogeneously dense)238 (35%)243 (36%) IV (extremely dense)98 (15%)102 (15%) Mean age at cancer detection49,6 ± 7.049,8 ± 4,70.74No cancer – no. (%)634 (94%)666 (98%) Invasive breast cancers – no. (%)25 (4%)7 (1%)&lt;0.001 (noBC/inv BC/DCIS)DCIS – no. (%)16 (2%)7 (1%) Median size of invasive cancers8 mm17 mm0.006T1a/b15 (60%)1 (14%) T1c7 (28%)4 (57%)0.078 (T1a-b/T1c/≥ T2)≥ T23 (12%)2 (29%) Node pos5 (20%)5 (71%)0.019 (N+/-)Node negative20 (80%)2 (29%) DCIS grade 15 (31%)2 (29%) DCIS grade 28 (50%)4 (57%)1 (dcis gr1,2,3)DCIS grade 33 (19%)1 (14%) *Determined by radiologists, according to the fourth ACR BI-RADS edition

Citation Format: Tilanus-Linthorst MM, Saadatmand S, Geuzinge AH, Rutgers EJ, Mann R, de Roy van Zuidewijn DB, Zonderland HM, Tollenaar RA, Lobbes MB, Ausems MG, van 't Riet M, Hooning MJ, Mares-Engelbert I, Luiten EJ, Heijnsdijk EA, Verhoef C, Karssemeijer N, Oosterwijk JC, Obdeijn I-M, de Koning HJ. MRI breast cancer screening compared to mammography in women with a familial risk: A multicenter randomized controlled trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-13-01.

Abstract P3-10-01: Tamoxifen and contralateral breast cancer (CBC) risk for BRCA1 and BRCA2 mutation carriers: An updated analysis of data from the Kathleen Cuningham Foundation consortium for research into familial breast cancer, the International BRCA1 and BRCA2 Carrier cohort study and the breast cancer family registry

Background: Findings from an analysis published in 2013, using combined retrospective and prospective data pooled from 3 cohort studies, were consistent with tamoxifen use after 1st breast cancer (BC) being associated with reduced CBC risk for both BRCA1 and BRCA2 mutation carriers, although the analysis of prospective data alone (based on 100 incident CBCs) gave inconclusive results. The association did not differ by estrogen receptor (ER) status of the 1st BC, suggesting that tamoxifen may be a useful secondary BC prevention agent for mutation carriers regardless of the ER status of their 1st BC. The aim of this updated analysis was to assess these associations after incorporating data from an additional 1,279 mutation carriers and with further follow-up providing 153 additional prospective CBC events. Methods: Eligible women were BRCA1 and BRCA2 mutation carriers diagnosed with unilateral BC since 1970 and with no other invasive cancer or tamoxifen use before their 1st BC. They were followed up from their 1st BC (or, for the prospective analysis, from the later of recruitment and 1st BC diagnosis) to the development of CBC or censoring (at contralateral mastectomy, death or loss to follow-up). Hazard ratios (HRs) for CBC associated with tamoxifen use were estimated using Cox regression, adjusting for year and age of diagnosis, country and bilateral oophorectomy; analyses were also stratified by ER status of the 1st BC. Results: This 2017 analysis includes 3,743 mutation carriers (BRCA1 2,343; BRCA2 1,400) with 21,436 person years of follow-up. Compared with the 2013 analysis, the strengths of the inverse associations were attenuated after including the additional data.

 2017  2013   TotalCBCHR (95% CI) p-valueTotalCBCHR (95% CI) p-value NN NN BRCA1      Combined*      Tam 1st BC      No17615141.0012003381.00Yes5821290.77 (0.63-0.95) 0.01383350.38 (0.27-0.55) &lt;0.001Prospective      Tam 1st BC      No9841321.00481541.00Yes369400.82 (0.57-1.20) 0.31176120.58 (0.29-1.13) 0.1BRCA2      Combined*      Tam1st BC      No6361661.004271151.00Yes764990.58 (0.44-0.76) &lt;0.001454320.33 (0.22-0.50) &lt;0.001Prospective      Tam 1st BC      No389461.00191211.00Yes497350.68 (0.40-1.15) 0.15235130.48 (0.22-1.05) 0.07*Combined = retrospective and prospective, N=number, BRCA1 & BRCA2=mutation carriers, Tam 1st BC= Tamoxifen for 1st Breast Cancer

In this updated prospective analysis, the inverse association between tamoxifen use for 1st BC and CBC risk was most apparent for women with ER positive 1st BC, especially for BRCA2 mutation carriers: BRCA1 ER positive HR=0.45 (95% CI 0.17-1.22, p=0.12), BRCA1 ER negative HR= 0.87 (95% CI 0.45-1.67, p=0.67), BRCA2 ER positive HR=0.33 (95% CI 0.15-0.74, p&lt;0.007), BRCA2 ER negative HR=1.12 (95% CI 0.27-4.70, p=0.88).

Conclusions: Tamoxifen use for 1st BC might reduce CBC risk for mutation carriers, but predominantly for those with an ER positive 1st BC. These data do not support use of tamoxifen to prevent CBC for mutation carriers with ER negative BC.

Citation Format: Phillips K-A, Milne RL, Bassett JK, Hopper JL, Buys SS, Daly MB, Hooning MJ, Mooij TM, Andrieu N, Antoniou AC, Rookus MA, Easton DF, Mary-Beth T. Tamoxifen and contralateral breast cancer (CBC) risk for BRCA1 and BRCA2 mutation carriers: An updated analysis of data from the Kathleen Cuningham Foundation consortium for research into familial breast cancer, the International BRCA1 and BRCA2 Carrier cohort study and the breast cancer family registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-10-01.

Abstract P2-07-04: Risk of primary and contralateral breast cancer in BRCA1/2 mutation carriers previously affected with ovarian cancer

Introduction: BRCA1/2 mutation carriers are at increased risk of developing breast cancer (BC) and ovarian cancer (OC). However, for BRCA1/2 mutation carriers previously affected with OC, primary BC (PBC) and contralateral BC (CBC) risks might be lowered due to OC treatment, but data hereon are limited. Accurate BC risk estimates are essential for counseling and optimal decision making on BC surveillance and risk-reducing mastectomy (RRM) after diagnosis of BRCA1/2-associated OC.

Methods: From the national HEBON cohort study, we selected female BRCA1/2 mutation carriers born from 1940 and at risk of PBC (n=2019; 1194 BRCA1, 825 BRCA2) or at risk of CBC (n=1276; 839 BRCA1, 437 BRCA2). Eligibility criteria for the PBC risk analyses included no history of PBC and both breasts in situ at DNA testing. For the CBC risk analyses, CBC before DNA testing was not allowed and the contralateral breast had to be unaffected at DNA testing. To estimate the association between OC and BC risk, we used the Fine and Gray regression model, with OC as a time-dependent variable and death as competing risk event. The observation started at the age of DNA testing, age 35, or – for the CBC risk analyses – age at PBC diagnosis, whichever came last. Censoring events were RRM, study closing date (i.e. 2014-12-31), and – for the CBC risk analyses – ipsilateral BC recurrence. All analyses were performed separately for BRCA1 and BRCA2 mutation carriers.

Results: For the PBC analyses, we selected 236 BRCA1/2 mutation carriers with OC and 1783 BRCA1/2 mutation carriers without OC (median age at start study 53 and 41 years, respectively). During a mean follow-up (FU) of 5.2 years, 15 (6%) OC patients developed PBC after OC, while PBC was diagnosed in 262 (15%) women without OC. OC diagnosis was associated with a lower PBC risk in BRCA1 mutation carriers (HR, 0.27; 95% CI, 0.14–0.53) but not in BRCA2 mutation carriers (HR, 0.88; 95% CI, 0.34–2.27). The cumulative PBC incidence at age 70 in BRCA1 mutation carriers was 25% for OC patients and 66% for women without OC, and in BRCA2 mutation carriers 49% for OC patients and 53% for women without OC.

For the CBC analyses, we selected 99 BRCA1/2 mutation carriers affected with PBC and OC, and 1177 BRCA1/2-associated PBC patients without OC (median age at start study 54 and 46 years, respectively). During a mean FU of 3.5 years, 8 (8%) PBC/OC patients developed CBC after OC, while CBC was diagnosed in 131 (11%) PBC patients without OC. In BRCA1 mutation carriers, OC diagnosis was non-significantly associated with a lower CBC risk (HR, 0.44; 95% CI, 0.19–1.03). For BRCA2 mutation carriers the HR was 1.65 (95% CI, 0.34–8.04). The cumulative CBC incidence at age 70 in BRCA1 mutation carriers was 40% for OC patients and 68% for patients without OC; for BRCA2 mutation carriers the number of CBCs was too small to obtain meaningful estimates.

Conclusion:­ For BRCA1 mutation carriers affected with OC the risk of developing subsequent BC is lower than for BRCA1 mutation carriers without OC. Our data suggest that the current BC prevention strategies should be reconsidered for OC patients carrying a BRCA1 mutation, possibly including less intensive BC surveillance, and RRM being indicated only for a subgroup of OC patients.

Citation Format: Heemskerk-Gerritsen BAM, Hooning MJ, van Doorn HC, Collée MJ, Koppert LB, Jager A, van den Ouweland AMW, Netherlands H, Seynaeve C, Kriege M. Risk of primary and contralateral breast cancer in BRCA1/2 mutation carriers previously affected with ovarian cancer [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 P2-07-04.

Timing of risk reducing mastectomy in breast cancer patients carrying a BRCA1/2 mutation: retrospective data from the Dutch HEBON study

It is expected that rapid genetic counseling and testing (RGCT) will lead to increasing numbers of breast cancer (BC) patients knowing their BRCA1/2 carrier status before primary surgery. Considering the potential impact of knowing one’s status on uptake and timing of risk-reducing contralateral mastectomy (RRCM), we aimed to evaluate trends over time in RRCM, and differences between carriers identified either before (predictively) or after (diagnostically) diagnosis. We collected data from female BRCA1/2 mutation carriers diagnosed with BC between 1995 and 2009 from four Dutch university hospitals. We compared the timing of genetic testing and RRCM in relation to diagnosis in 1995–2000 versus 2001–2009 for all patients, and predictively and diagnostically tested patients separately. Of 287 patients, 219 (76 %) had a diagnostic BRCA1/2 test. In this cohort, the median time from diagnosis to DNA testing decreased from 28 months for those diagnosed between 1995 and 2000 to 14 months for those diagnosed between 2001 and 2009 (p < 0.001). Similarly, over time women in this cohort underwent RRCM sooner after diagnosis (median of 77 vs. 27 months, p = 0.05). Predictively tested women who subsequently developed BC underwent an immediate RRCM significantly more often than women who had a diagnostic test (21/61, 34 %, vs. 13/170, 7.6 %, p < 0.001). Knowledge of carrying a BRCA1/2 mutation when diagnosed with BC influenced decisions concerning primary surgery. Additionally, in more recent years, women who had not undergone predictive testing were more likely to undergo diagnostic DNA testing and RRCM sooner after diagnosis. This suggests the need for RGCT to guide treatment decisions.

Breast cancer risk after salpingo-oophorectomy in healthy BRCA1/2 mutation carriers: revisiting the evidence for risk reduction

BACKGROUND

Previous studies have reported a breast cancer (BC) risk reduction of approximately 50% after risk-reducing salpingo-oophorectomy (RRSO) in BRCA1/2 mutation carriers, but may have been subject to several types of bias. The purpose of this nationwide cohort study was to assess potential bias in the estimated BC risk reduction after RRSO.

METHODS

We selected BRCA1/2 mutation carriers from an ongoing nationwide cohort study on Hereditary Breast and Ovarian Cancer in the Netherlands (HEBON). First, we replicated the analytical methods as previously applied in four major studies on BC risk after RRSO. Cox proportional hazards models were used to calculate hazard ratios and conditional logistic regression to calculate odds ratios. Secondly, we analyzed the data in a revised design in order to further minimize bias using an extended Cox model with RRSO as a time-dependent variable to calculate the hazard ratio. The most important differences between our approach and those of previous studies were the requirement of no history of cancer at the date of DNA diagnosis and the inclusion of person-time preceding RRSO.

RESULTS

Applying the four previously described analytical methods and the data of 551 to 934 BRCA1/2 mutation carriers with a median follow-up of 2.7 to 4.6 years, the odds ratio was 0.61 (95% confidence interval [CI] = 0.35 to 1.08), and the hazard ratios were 0.36 (95% CI = 0.25 to 0.53), 0.62 (95% CI = 0.39 to 0.99), and 0.49 (95% CI = 0.33 to 0.71), being similar to earlier findings. For the revised analysis, we included 822 BRCA1/2 mutation carriers. After a median follow-up period of 3.2 years, we obtained a hazard ratio of 1.09 (95% CI = 0.67 to 1.77).

CONCLUSION

In previous studies, BC risk reduction after RRSO in BRCA1/2 mutation carriers may have been overestimated because of bias. Using a design that maximally eliminated bias, we found no evidence for a protective effect.

FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

BACKGROUND

Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium.

METHODS

Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression.

RESULTS

Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2.

CONCLUSION

Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2.

Abstract P5-05-05: Lower mitotic activity in BRCA1/2-associated primary breast cancers occurring after risk-reducing salpingo-oophorectomy

Background Bilateral salpingo-oophorectomy reduces breast cancer (BC) risk by about 50% in BRCA1/2 mutation carriers when performed premenopausally. It has been hypothesized that growth activity of BCs originating after risk-reducing salpingo-oophorectomy (RRSO) is lower. We compared tumor characteristics and growth rates of BRCA1/2-associated primary BCs (PBCs) detected after RRSO with those of tumors originating without RRSO.

Methods From a cohort of 271 female BRCA1/2-associated patients with screen detected BC, 20 BRCA1/2 mutation carriers with PBC detected ≥12 months after RRSO were selected (RRSO group). Controls were 36 BRCA1/2 mutation carriers with PBC detected without RRSO (non-RRSO group) matched for age at PBC diagnosis (± 2.5 years) and for BRCA1 or BRCA2 mutation (intended matching ratio 1:2). Tumor growth rates, expressed as tumor volume doubling times (DT), were calculated. Pathology samples were revised for histological subtype, tumor differentiation grade, estrogen receptor (ER), progesterone receptor (PR) and HER2 status. Imaging examinations (magnetic resonance imaging (MRI), mammography) before and at BC diagnosis were revised.

Results Median age at PBC diagnosis was 52 years (range 35-67). MRI detected more BC than mammography in the RRSO-group as compared to the non-RRSO group (83% vs. 39%, P = 0.02). Tumor size at diagnosis was smaller in the RRSO group (11.0 mm vs. 17.0 mm, P = 0.01). Mitotic activity indexes (MAI) in the RRSO and non-RRSO group were 12 vs. 22 mitotic counts/2 mm2 (P = 0.02). No significant differences in differentiation grade, ER and HER2 status were found. PR-status was more often positive in the RRSO group without reaching statistical significance (38% vs. 13%, P = 0.07). Median DT in the RRSO group was 124 days (range 89-193) and 93 days (range 54-253) in the non-RRSO group (P = 0.47).

Conclusion BC occurring after RRSO in BRCA mutation carriers features a lower MAI, suggesting a less aggressive biological behavior. When confirmed in larger series, this may have consequences for BC screening protocols for BRCA1/2 mutation carriers after RRSO.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-05-05.

Substantial breast cancer risk reduction and potential survival benefit after bilateral mastectomy when compared with surveillance in healthy BRCA1 and BRCA2 mutation carriers: a prospective analysis

BACKGROUND

To prospectively assess the efficacy of bilateral risk-reducing mastectomy (BRRM) when compared with surveillance on breast cancer (BC) risk and mortality in healthy BRCA1 and BRCA2 mutation carriers.

PATIENTS AND METHODS

Five hundred and seventy healthy female mutation carriers (405 BRCA1, 165 BRCA2) were selected from the institutional Family Cancer Clinic database. Eventually, 156 BRCA1 and 56 BRCA2 mutation carriers underwent BRRM. The effect of BRRM versus surveillance was estimated using Cox models.

RESULTS

During 2037 person-years of observation (PYO), 57 BC cases occurred in the surveillance group versus zero cases during 1379 PYO in the BRRM group (incidence rates, 28 and 0 per 1000 PYO, respectively). In the surveillance group, four women died of BC, while one woman in the BRRM group presented with metastatic BC 3.5 years after BRRM (no primary BC), and died afterward, yielding a HR of 0.29 (95% CI 0.02-2.61) for BC-specific mortality.

CONCLUSIONS

In healthy BRCA1/2 mutation carriers, BRRM when compared with surveillance reduces BC risk substantially, while longer follow-up is warranted to confirm survival benefits.

Chemosensitivity and outcome of BRCA1- and BRCA2-associated ovarian cancer patients after first-line chemotherapy compared with sporadic ovarian cancer patients

BACKGROUND

Because it is insufficiently clear whether BRCA-associated epithelial ovarian cancer (EOC) is more chemosensitive than sporadic EOC, we examined response to chemotherapy, progression-free survival (PFS) and overall survival (OS) in BRCA1- and BRCA2-associated versus sporadic EOC patients.

METHODS

Data about patient characteristics, response to and outcome after primary therapy, including chemotherapy, were collected from 99 BRCA1, 13 BRCA2 and 222 sporadic patients. Analyses were carried out using a chi-square test and Kaplan-Meier and Cox regression methods.

RESULTS

Complete response (CR) or no evidence of disease (NED) was observed in 87% of the BRCA1 patients, progressive disease (PD) in 2%, being 71% and 15%, respectively, in sporadic EOC patients (P = 0.002). In BRCA2 patients, 92% had CR/NED, and none PD (P = 0.27). Median PFS in BRCA1, BRCA2 and sporadic patients was 2.1 [95% confidence interval (CI) 1.9-2.5] years (P = 0.006), 5.6 (95% CI 0.0-11.5) years (P = 0.008) and 1.3 (95% CI 1.1-1.5) years, respectively. Median OS in the three groups was 5.9 (95% CI 4.7-7.0) years (P < 0.001), >10 years (P = 0.008), and 2.9 (95% CI 2.2-3.5) years, respectively. A trend for a longer PFS and OS in BRCA2 compared with BRCA1 patients was observed.

CONCLUSION

Compared with sporadic EOC patients, both BRCA1- and BRCA2-associated patients have improved outcomes after primary therapy, including chemotherapy.

Prevention of primary and contralateral breast cancer by risk reducing salpingo-oophorectomy in high risk women with a BRCA1/2 mutation or familial predisposition

Abstract #504

Introduction: Risk reducing salpingo-oophorectomy (RRSO) has become an important preventive option against ovarian/fallopian tube cancer, while it is also risk reducing regarding breast cancer (BC) in women with a BRCA1 or BRCA2 mutation. Recently a difference in efficacy of RRSO concerning the occurrence of BC has been suggested for BRCA1 and BRCA2 mutation carriers, while no data are available on the protective effect of RRSO in women from a hereditary breast/ovarian cancer (HBOC) family without a proven BRCA mutation. Further, it is not known whether the BC risk reduction after RRSO equally applies to primary (PBC) and contralateral BC (CBC).&#x2028; Methods: The occurrence of PBC and CBC was prospectively studied in 639 women ≥ 30 years (330 BRCA1 mutation carriers, 117 BRCA2 mutation carriers, and 192 HBOC women) who were enrolled in a breast/ovarian cancer surveillance program at the Rotterdam Family Cancer Clinic. Women with a history of BC without recurrent disease were eligible if BC treatment did not involve adjuvant systemic therapy. Demographics and follow-up (FU) information up to December 31, 2007, were extracted from the medical records. Ninety-eight BRCA1 mutation carriers, 33 BRCA2 mutation carriers and 15 HBOC women eventually underwent RRSO. Results were analyzed separately for women being at risk for PBC (n=489) and for CBC (n=164). The effect of RRSO on the incidence of BC was analyzed using a Cox proportional hazards model in which RRSO was modeled as a time-dependent covariate.&#x2028; Results: During a mean FU of 5.5 years, RRSO was associated with a reduction in BC risk of 48% (HR=0.52; 95% CI, 0.26-1.02; p=0.058) versus 81% (HR=0.19; 95% CI, 0.02-1.95; p=0.161) in BRCA1 and BRCA2 mutation carriers, respectively. In BRCA1 mutation carriers, PBC was reduced by 74% (HR=0.26; 95% CI, 0.08-0.89; p=0.032), and CBC by 29% (HR=0.71; 95% CI, 0.23-2.16; p=0.544). In BRCA2 mutation carriers no cases of PBC occurred after RRSO (HR=0,00; 95% CI, not estimable), while 1 CBC was diagnosed (HR=0.25; 95% CI, 0.01-5.62; p=0.379). In HBOC women no BC cases were observed after RRSO.&#x2028; Conclusions: RRSO is associated with a BC risk reduction in both BRCA1 and BRCA2 mutation carriers. The risk reductive effect is more pronounced regarding PBC as compared to CBC in BRCA1 mutation carriers. Although a similar trend is suggested for BRCA2 mutation carriers, larger numbers and longer FU are needed to draw firm conclusions.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 504.

Breast cancer: a study into the value of a historical group as comparative material for new methods of treatment

A large group of consecutive patients were studied who had been treated for a primary breast carcinoma by a radical mastectomy at the Netherlands Cancer Institute, during the period of 1960-1974. One of the objectives of that retrospective study was to record the results of treatment of a historical group of patients in such a way that they could presumably serve as a reference for new methods of treatment of breast cancer. To verify the validity of this presumption, the present study compares the treatment results of patients from the EORTC trial 10801, which addresses the value of breast conserving procedures, with that of matched controls from the historical group mentioned above. Matching was carried out with respect to the following prognostic factors: age, tumor size, localization, (number of) positive axillary nodes and grade of malignancy. Analysis of the results strongly suggests that the prognosis for the patients from the historical group is worse than for both groups of patients from the trial 10801. Therefore, this study again confirms that a historical group is not suitable as comparative material for new ways of treatment of breast cancer, and that prospective randomized studies are required to test new treatment schedules.

Changing indications for breast conserving therapy: proportion of patients with operable breast cancer suitable for breast conservation

The changes in indication for breast conserving therapy and the proportion of operable stage-I and stage-II breast cancers suitable for breast conserving therapy were studied in three time periods. The percentage of patients treated with breast conserving therapy gradually increased through the years: 77/199 (39%) in 1980-1981, 122/245 (50%) in 1985-1987, and 168/305 (55%) in 1987-1989. Using the actual selection criteria more patients might have been candidates for breast conserving therapy: 69, 64 and 59 per cent respectively. In the period 1987-1989 almost all patients who were considered good candidates for breast conserving therapy had a breast sparing procedure. Indications widened in relation to age limit (less than or equal to 70 years) and, over the years, more factors became relative contra-indications: very young age, presence of extensive intra-ductal component, data from mammography (multicentricity, size and aspect of the lesion). About 40 per cent of the patients were no appropriate candidates for breast conserving therapy. This percentage would be higher when operable stage-III patients would have been included.