Feasibility of breast conservation therapy in metachronous or synchronous bilateral breast cancer

Tumor Characteristics of Bilateral Breast Cancer Compared with Unilateral Breast Cancer

BACKGROUND

Bilateral breast cancer (BC) has an incidence of 1 to 3 %. This study aimed to describe the clinicopathologic characteristics and management of bilateral BC, estimate disease-free survival (DFS), and compare DFS with unilateral BC.

METHODS

A retrospective analysis was performed for patients who had bilateral invasive BC or unilateral invasive BC and contralateral ductal carcinoma in situ (DCIS) treated at Mayo Clinic Rochester from 2008 to 2022. A 4:1 matched cohort of patients with unilateral invasive BC was used for comparison. The groups were compared using Wilcoxon rank-sum or chi-square tests. Disease-free survival was analyzed using the Kaplan-Meier method and log-rank test, with Cox proportional hazards regression used for multivariable analysis.

RESULTS

The study identified 278 cases of bilateral breast cancer (177 cases of bilateral invasive cancer and 101 cases of unilateral invasive cancer with contralateral DCIS), representing 4.1 % of invasive BCs. Biologic subtype was concordant between sides in 79.8 % of the patients. Initial surgery was bilateral mastectomy for 76.6 %, bilateral lumpectomy for 20.5 %, and unilateral mastectomy with unilateral lumpectomy for 2.9 % of the patients. Pathogenic variants in breast cancer predisposition genes were present in 21.7 % of those tested. The patients who had bilateral BC presented with a higher cT category than the patients who had unilateral BC (p = 0.02), and a higher proportion presented with ILC (17.3 % vs 10.9 %; p = 0.004), estrogen receptor-positive (ER+) disease (89.2 % vs 84.2 %; p = 0.04), multicentric/multifocal disease (37.1 % vs 24.3 %; p < 0.001), breast cancer pathogenic variant (21.7 % vs 12.4 %; p = 0.02), and palpable presentation (48.2 % vs 40.8 %; p = 0.03). The patients with bilateral BC showed DFS similar to that for the unilateral BC cohort (p = 0.71).

CONCLUSIONS

Bilateral BCs most commonly are biologically concordant between sides. Bilateral BC presented more commonly with larger tumors, lobular histology, ER+ status, multicentricity or multifocality, pathogenic variant, and palpable disease. Bilateral BC is not associated with worse DFS than unilateral BC.

Concordance of Hormone Receptor Status and BRCA1/2 Mutation Among Women With Synchronous Bilateral Breast Cancer

Goals: BRCA1/2 mutations are associated with bilateral breast cancer. The extent of concordance between synchronous bilateral breast cancer (SBBC) tumors with respect to hormone receptor expression and BRCA1/2 mutations is unknown. We investigated the distribution of BRCA1/2 mutations and bilateral estrogen receptor (ER) status in SBBC. Methods: A retrospective analysis was performed on 15,337 patients with primary breast cancer who underwent surgical treatment at the Fudan University Shanghai Cancer Center between 2007 and 2014. We included 163 patients with synchronous bilateral breast cancer who had germline BRCA1/2 mutations testing. BRCA1/2 pathogenic/likely pathogenic mutations and other clinicopathological characteristics were studied in further analyses. Results: Patients with SBBC developed breast cancer at an older age and had a higher rate of ER positivity than patients with UBC (p < 0.001, separately). In contrast, 14.1% of SBBC patients had carcinomas with a lobular component in either breast based on pathological reports (p < 0.001). Twelve patients had BRCA1 mutations, and 14 patients had BRCA2 mutations, while no patients had mutations in both genes. The BRCA1/2 mutation rate was higher in younger patients (23.4 vs. 11.1%, p = 0.036). SBBC patients with a family history of breast cancer or bilateral ER-negative disease had a higher frequency of BRCA1/2 mutations than the cohort without a history of these conditions. SBBC with a bilateral ER-discordant status had a very low frequency of BRCA1/2 mutations (5.6%). Patients with an ER-positive (concordant or discordant) status had better 3-year disease-free survival than patients with a concordant ER-negative status (HR = 0.324, 95% CI: 0.126-0.837, P = 0.020). However, the outcomes were similar during long-term follow-up. Pathological lymph node stage was the only prognostic factor for SBBC in both univariate and multivariate Cox analyses. Conclusions: Our study shows that Chinese women with SBBC have different characteristics from their UBC counterparts. SBBC patients with a younger age, family history of breast cancer, or bilateral ER-negative disease are more likely to have BRCA1/2 mutations. SBBC patients with a concordant ER-negative status had worse early outcomes. Our results suggest that there may be additional factors underlying the tumor biology and genetics of SBBC.

pCR rates in patients with bilateral breast cancer after neoadjuvant anthracycline-taxane based-chemotherapy - A retrospective pooled analysis of individual patients data of four German neoadjuvant trials

PURPOSE

Patients with bilateral breast cancer (BBC) are usually excluded from participating in clinical trials and little is known about the response and outcome of BBC to neoadjuvant chemotherapy compared to unilateral BC (UBC).

METHODS

We prospectively captured the information on patients with BBC in our database treated within four neoadjuvant chemotherapy trials and collected retrospectively the rate of pathological complete response (pCR) defined as ypT0 ypN0, ypT0/is ypN0, ypT0 ypNX, clinical and histologic parameters. Synchronous carcinoma in the contralateral breast was considered as the non-indicator lesion. Patients with UBC only treated within the same neoadjuvant trials performed the control group.

RESULTS

From the 6727 patients treated within 4 German neoadjuvant trials 119 (1.8%) patients have been identified with the diagnosis of BBC. The pCR rate (ypT0 ypN0) was 12.6% in the non-indicator lesion group versus 10.9% the indicator lesion group versus 20.9% for patients with unilateral disease (p = 0.003). There were more advanced tumor stages and positive axillary lymph nodes in the indicator lesion than in the nonindicator lesion or in UBC. In 52.5% the molecular subtype was identical between indicator and non-indicator lesion with more triple negative and HER2 positive BC in the group of UBC. The disease free survival rate (DFS) was 25.8% for patients with UBC versus 39.6% for patients with BBC.

CONCLUSION

The selection for the indicator lesion was based on tumor size, nodal status and inclusion criteria. Patients with BBC patients had a lower pCR rate and a lower DFS.

Synchronous Bilateral Breast Cancers

BACKGROUND

Bilateral breast cancer (BBC) is not an uncommon entity in contemporary breast clinics. Improved life expectancy after breast cancer treatment and routine use of contra-lateral breast mammography has led to increased incidence of BBC. Our study objective was to define the epidemiological and tumour characteristics of BBC in India.

MATERIALS AND METHODS

A total of 1251 breast cancer patients were treated during the period January 2007 to March 2015 and 30 patients were found to have BBC who constituted the study population (60 tumour samples). Synchronous bilateral breast cancers (SBC) was defined as two tumours diagnosed within an interval of 6 months and a second cancer diagnosed after 6 months was labelled as metachronous breast cancer (MBC). Analyses of patient and tumour characteristics were done in this prospective data base of BBC patients.

RESULTS

Median patient age was 66 years (range 39-85). Majority of the patients had SBC (n=28) and in 12 patients the second tumour was clinically occult and detected only by mammography of the contra-lateral breast. The second tumour was found at lower tumour size compared to the first in 73% of cases and was negative for axillary metastasis in 80% of cases (24/30). Infiltrating ductal carcinoma was the commonest histological type (n=51) and majority of the tumours were ER/PR positive (50/60). Her2 was overexpressed in 13 tumours (21%). Over 70% (22/30) of patients had similar histology in both breasts and amongst them grade concordance was present in about 69% (15/22) of patients. Concordance rates of ER, PR and Her2 statuses were 83%, 80% and 90% respectively. Bilateral mastectomy was the commonest surgery performed in 80% of the patients followed by bilateral breast conservation in 13%. At the end of study period, 26 patients were alive and disease free. Median survival was 29 months (range 3-86 months).

CONCLUSION

In most patients with BBC, the second tumour is identified at an early stage than index tumours supporting the importance of contralateral breast cancer screening at the time of primary diagnosis and during follow-up. BBC occurs more frequently in old age group and majority of these tumours are estrogen dependent. There is good pathological concordance between the index tumour and the contralateral breast cancer.

Use of tomotherapy in treatment of synchronous bilateral breast cancer: dosimetric comparison study

OBJECTIVE

Synchronous malignancy in both breasts is a rare incidence. The present study aims at dosimetric comparison of conventional bitangential radiotherapy (RT) technique with conventional [field-in-field (FIF)] and rotational [Helical TomoTherapy(®) and TomoDirect™ (TD); Accuray Inc., Sunnyvale, CA] intensity-modulated RT for patients with synchronous bilateral breast cancer (SBBC).

METHODS

CT data sets of 10 patients with SBBC were selected for the present study. RT was planned for all patients on both sides to whole breast and/or chest wall using the above-mentioned techniques. Six females with breast conservation on at least one side also had a composite plan along with tumour bed (TB) boost using sequential electrons for bitangential and FIF techniques or sequential helical tomotherapy (HT) boost (for TD) or simultaneous integrated boost (SIB) for HT.

RESULTS

All techniques produced acceptable target coverage. The hotspot was significantly lower with FIF technique and HT but higher with TD. For the organs at risk doses, HT resulted in significant reduction of the higher dose volumes. Similarly, TD resulted in significant reduction of the mean dose to the heart and total lung by reducing the lower dose volumes. All techniques of delivering boost to the TB were comparable in terms of target coverage. HT-SIB markedly reduced mean doses to the total lung and heart by specifically lowering the higher dose volumes.

CONCLUSION

This study demonstrates the cardiac and pulmonary sparing ability of tomotherapy in the setting of SBBC.

ADVANCES IN KNOWLEDGE

This is the first study demonstrating feasibility of treatment of SBBC using tomotherapy.

Prognosis of synchronous bilateral breast cancer

Background

The prognosis of patients with synchronous bilateral breast cancer (SBBC) is usually based on the tumour with the worst pathological features. There is little evidence in the literature for this assumption, potentially impairing reasoned decisions on optimal adjuvant therapy.

Methods

This was a case–control study in which 68 women with SBBC were matched with 128 women with unilateral breast cancer. Both the GuysRisk prognostic model and the Nottingham Prognostic Index were used to determine the bilateral tumour with the poorer prognosis. Controls were matched for age, menopausal status, date of diagnosis, histological type and grade, and oestrogen receptor and axillary node status.

Results

Both prognostic models indicated the same side tumour with the worst prognosis. Kaplan–Meier survival curves for both disease-free and overall survival showed no significant difference in outcome between the two groups.

Conclusion

Prognosis was determined by the tumour with the worst prognosis, with no additional worsening of outcome incurred from the second tumour.

A case of metachronous bilateral breast cancer with bilateral radiation pneumonitis after breast-conserving therapy

We report a patient with metachronous bilateral breast cancer who has twice developed radiation pneumonitis after breast-conserving therapy for each breast. The patient was a 48-year-old woman, who presented with Stage I right breast cancer. After wide excision of the right breast tumor and dissection of level I axillary lymph nodes, systemic therapy with oral 5-FU and tamoxifen was started. Subsequently, tangential irradiation with a total dose of 50 Gy in 25 fractions was given. Seven months after irradiation, she developed respiratory symptoms and radiation pneumonitis was diagnosed. The symptoms resolved with oral prednisolone. Thirty months after the right breast cancer treatment, Stage I left breast cancer was diagnosed. After wide excision of the left breast tumor and partial removal of the level I axillary lymph nodes, the same oral systemic chemo-hormonal therapy was initiated. Thereafter, tangential irradiation with a total dose of 50 Gy in 25 fractions was given. Four months after irradiation, she developed respiratory symptoms. A chest X-ray showed an area of increased density in the left lung consistent with radiation pneumonitis. The symptoms were mild and they improved spontaneously without medication. Although there is insufficient evidence to justify or withhold whole breast radiation therapy from patients with a history of contralateral breast cancer and radiation pneumonitis, it is essential to discuss the adequacy of whole breast irradiation and the possibility of alternative approaches, such as breast-conserving surgery without irradiation or partial breast irradiation for this rare condition.

Reconstruction mammaire bilatérale par lambeau myocutanéograisseux de grand dorsal (31 cas consécutifs)

PURPOSE OF THE STUDY

The purpose of this study was to analyse the advantages, disadvantages and results of bilateral breast reconstruction by autologous latissimus dorsi flap.

MATERIAL AND METHOD

Thirty-one two-stage consecutive bilateral breast reconstructions were performed by the same operator between 1993 and 2001. All the reconstructions, in immediate or delayed manner, were indicated after radical or skin sparing mastectomy for breast cancer. We used the autologous latissimus dorsi flap for all cases. The reconstruction of the second breast was always delayed of a few months to avoid back's complications. We reviewed the charts of these patients retrospectively. Preoperative data, postoperative complications, dorsal seroma occurrence, morphological results and patient's satisfaction were evaluated. Median follow-up was 22 months.

RESULTS

The results confirm the procedure's reliability. Comparative rates of postoperative complications are not significantly different between first and contralateral breast reconstruction. Functional after-effects of bilateral latissimus dorsi harvesting are moderate. The aesthetics results have been judged as very good in 84% of cases and good in 16%. The satisfaction rate of the patients is high: 90,3% are pleased, 6,5% are satisfied and 3,2% are moderately satisfied.

CONCLUSION

The autologous latissimus dorsi flap allows a two-stage bilateral breast reconstruction. This procedure is not indicated for simultaneous bilateral breast reconstruction; it is the main drawback of this technique. So we believe that this procedure is an excellent alternative in all the indications of sequential bilateral breast reconstructions.

Breast-conserving therapy in patients with bilateral breast cancer: do today's treatment choices burn bridges for tomorrow?

PURPOSE

To determine how often initial treatment choices limit treatment options for subsequent breast cancer management in patients undergoing breast-conserving therapy (BCT), in particular with treatment of internal mammary nodes.

METHODS AND MATERIALS

Between January 1985 and June 2001, 464 women with pathologic Stage 0, I, and II (T0-2, N0-1) breast cancer underwent BCT at our institution. All 464 patients had computed tomography-based treatment planning. In patients with bilateral breast cancer, the planning computed tomography scans were used to determine the impact initial radiation therapy fields had on treatment options for subsequent contralateral breast cancer.

RESULTS

There were 500 breast cancers diagnosed in 464 patients. Thirty-six patients (8%) had bilateral breast cancer with 9 (2%) synchronous and 27 (6%) metachronous primaries. In 80 patients, the ipsilateral internal mammary nodes were explicitly treated. Initial breast cancer treatment choices impacted subsequent treatment decisions for the contralateral breast in only 2 of 464 patients (0.4%) in the study: 2 of 80 patients (2.5%) whose internal mammary nodes were treated, and 2 of 27 patients (7.4%) who developed metachronous bilateral breast cancer.

CONCLUSIONS

Initial BCT, including internal mammary node irradiation, rarely compromised future contralateral breast-conserving therapy.

New trends in breast conservation therapy

Breast conservation therapy for early-stage invasive breast cancer provides survival equivalent to mastectomy. Careful patient selection and surgical technique are necessary to minimize local recurrence. Extensive studies of breast conservation therapy over the past 15 years have identified risk factors for local recurrence, and have proven that certain cases previously thought to be ineligible for lumpectomy (such as occult breast cancer, locally advanced breast cancer, macromastia, and cancer in pregnant patients), can be safely managed with modified BCT approaches. Recent trends in breast cancer management, such as expanded applications of induction chemotherapy, use of magnetic resonance imaging and ultra sound, and touch-prep cytology for intraoperative margin evaluation, can improve success rates for BCT. New developments with brachytherapy may also improve BCT availability by shortening duration of treatment. Innovations with minimally invasive tumor ablation techniques are investigational at present, but may obviate the need for surgical resections in selected patients in the future. Local recurrences that develop after breast conservation therapy should be managed aggressively, as long-term survival can frequently be achieved.

Management of breast carcinoma identified intraoperatively during reduction mammaplasty

Before reduction mammaplasty, patients should be assessed for breast cancer risk and evaluated with physical examination and mammography. Patients determined to be at increased risk should be informed of the possibility of occult breast carcinoma and the potential treatment options. Intraoperative discovery of an occult carcinoma may allow for breast conservation therapy under certain circumstances if an appropriate biopsy sample is taken from the tumor and if clear margins are obtained.

Surveillance mammography after treatment of primary breast cancer: a systematic review

As the prevalence of diagnosed breast cancer increases, it is important to define how best to provide long-term follow-up. Whereas many aspects of follow-up remain controversial, guidelines recommend surveillance mammograms as the only investigation to be performed routinely. We conducted a systematic review of the literature to elucidate the effect of routine surveillance mammograms on detecting ipsilateral recurrence (IR) and contralateral breast cancers (CBC). The systematic review yielded 15 articles. All were observational studies and ranked as level II-2 or III evidence. There were no randomized controlled trials identified. Most of the ten studies on detection of IR did not report on outcomes after detection. When reported, most studies found that the method of detection of IR did not influence overall survival or disease-free survival. Two of the nine studies on detection of CBC found that the CBC was detected at an earlier stage than the initial breast cancer, but did not report on long-term outcomes. This systematic review highlights the need for further research to help better define the optimum surveillance mammography regimen.

The long-term outcome of synchronous bilateral breast cancer is worse than metachronous or unilateral tumours

AIM

There is uncertainty in the literature as to whether bilateral breast cancer carries a worse prognosis than unilateral disease because some studies suggest that the development of a second primary does not influence survival, while others report a decreased survival in patients suffering from bilateral disease.

METHODS

A prospectively accrued and regularly validated database of 1945 patients with breast cancer treated in a district general hospital between 1963 and 1999 was analysed for clinical and pathological tumour characteristics including family history, grade, type of tumour, treatment and outcome.

RESULTS

Five per cent of patients (92) suffered from metachronous and 43 (2%) from synchronous bilateral breast cancer. A family history of breast cancer was more common in patients with metachronous bilateral breast cancer (38%), compared with the unilateral group (15%) and the synchronous bilateral breast cancer group (17%) (chi(2)=22.9, P<0.001). Patients with synchronous bilateral breast cancer had a significantly worse overall survival when compared with those with metachronous bilateral or unilateral breast cancer (log-rank test chi(2)=6.1, P=0.047).

CONCLUSION

Women with metachronous breast cancer were more likely to have positive family history, while those with synchronous bilateral breast cancer tend to have shorter survival when compared with those with unilateral breast cancer. Synchronous bilaterality is not, however, an independent risk factor on multivariate analysis.

Second cancers after conservative surgery and radiation for stages I-II breast cancer: identifying a subset of women at increased risk

PURPOSE

To assess the risk and patterns of second malignancy in a group of women treated with conservative surgery and radiation in a relatively contemporary manner for early-stage invasive breast cancer, and to identify a subgroup of these women at increased risk for a second cancer.

METHODS AND MATERIALS

From 1978 to 1994, 1,253 women with unilateral Stage I-II breast cancer underwent wide excision, axillary dissection, and radiation. The median follow-up was 8.9 years, with 446 patients followed for >or= 10 years. The median age was 55 years. Sixty-eight percent had T1 tumors and 74% were axillary-node negative. Radiation was directed to the breast only in 78%. Adjuvant therapy consisted of chemotherapy in 19%, tamoxifen in 19%, and both in 8%. Factors analyzed for their association with the cumulative incidence of all second malignancies, contralateral breast cancer, and non-breast cancer malignancy were: age, menopausal status, race, family history, obesity, smoking, tumor size, location, histology, pathologic nodal status, region(s) treated with radiation, and the use and type of adjuvant therapy.

RESULTS

One hundred seventy-six women developed a second malignancy (87 contralateral breast cancers at a median interval of 5.8 years, and 98 non-breast cancer malignancies at a median interval of 7.2 years). Nine women had both a contralateral breast cancer and non-breast cancer second malignancy. The 5- and 10-year cumulative incidences of a second malignancy were 5% and 16% for all cancers, 3% and 7% for contralateral breast cancer, 3% and 8%, for all second non-breast cancer malignancies, and 1% and 5%, respectively, for second non-breast cancer malignancies, excluding skin cancers. Patient age was a significant factor for contralateral breast cancer and non-breast cancer second malignancy. Young age was associated with an increased risk of contralateral breast cancer, while older age was associated with an increased the risk of a second non-breast cancer second malignancy. A positive family history increased the risk of contralateral breast cancer, but not non-breast cancer malignancies. The risk of a contralateral breast cancer increased as the number of affected relatives increased. Tamoxifen resulted in a nonsignificant decrease in contralateral breast cancer and an increase in non-breast cancer second malignancies. The 5-and 10-year cumulative incidences for leukemia and lung cancer were 0.08% and 0.2%, and 0.8% and 1%, respectively. There was no significant effect of chemotherapy or the regions treated with radiation on contralateral breast cancer or non-breast cancer second malignancy. The most common types of second non-breast cancer malignancies were skin cancers, followed by gynecologic malignancies (endometrial), and gastrointestinal malignancies (colorectal and pancreas).

CONCLUSION

The 10-years cumulative incidence of a second cancer in this study was 16%. Young age and family history predicted for an increased risk of contralateral breast cancer, and older age predicted for an increased risk of non-breast cancer malignancy. The majority of patients treated with conservative surgery and radiation with or without adjuvant systemic therapy will not develop a second cancer. Long-term follow-up is important to document the risk and patterns of second cancer, and knowledge of this risk and the patterns will influence surveillance and prevention strategies.

Reconstructive management of contralateral breast cancer in patients who previously underwent unilateral breast reconstruction

When a patient who has had unilateral breast reconstruction presents with a new cancer on the opposite side, the reconstructive management of the second breast can be unclear. This study was performed to determine whether reconstruction of the second breast is oncologically reasonable and to evaluate the reconstructive options available to these patients. Patients who had mastectomy with unilateral breast reconstruction between 1988 and 1994 and who had a minimal follow-up of 5 years from the initial breast cancer were reviewed. Of 469 patients reviewed, 18 patients (4 percent) were identified who developed contralateral breast cancer. Mean age at the initial breast cancer presentation was 43 years (range, 26 to 57 years), and mean age at presentation with contralateral breast cancer was 48 years (range, 36 to 67). The mean interval between the initial and contralateral breast cancer presentations was 5 years (range, 1 to 10 years). Mean follow-up from the time of contralateral breast cancer was 5 years (range, 1 to 9 years). In most cases, contralateral breast cancer presented at an early stage (13 of 18 patients; 72 percent), and a shift to an earlier stage at presentation of the contralateral cancer was evident compared with the initial breast cancer. Of the 18 patients who developed contralateral breast cancer, 16 (89 percent) had no evidence of disease, one was alive with disease, and one died. Reconstructive management after the initial mastectomy included 16 transverse rectus abdominis myocutaneous flaps (seven free and nine pedicled), one latissimus dorsi myocutaneous flap with implant, and one superior gluteal free flap. Surgical management of the second breast after contralateral breast cancer included breast conservation in two patients, mastectomy without reconstruction in four, and mastectomy with reconstruction in 12. Reconstruction of the second breast included one free transverse rectus abdominis myocutaneous flap, three extended latissimus dorsi flaps, two latissimus dorsi myocutaneous flaps with implants, three implants alone, two Rubens flaps, and one superior gluteal free flap. No major complications were noted after the reconstruction of the second breast. The best symmetry was obtained when similar methods and tissues were used on both sides. The incidence of contralateral breast cancer after mastectomy and unilateral breast reconstruction is low. In most cases, contralateral breast cancer presents at an earlier stage compared with the initial breast cancer, and the prognosis is good. In patients who develop a contralateral breast cancer after mastectomy and unilateral breast reconstruction, the reconstruction of the second breast after mastectomy is oncologically reasonable and should be offered to provide optimal breast symmetry and a better quality of life. The best result is obtained when similar methods and tissues are used on both sides.

Bilateral synchronous breast cancer: mode of detection and comparison of histologic features between the 2 breasts

BACKGROUND

Bilateral synchronous breast cancer is uncommon (accounting for 1.0%-2.6% of all patients with breast cancer), and most physicians do not accumulate a large personal experience of patients with this disease. We reviewed our experience with patients with bilateral synchronous breast cancer, focusing on the mode of detection and histologic features in the 2 breasts.

METHODS

The charts of patients who were treated at this institution for bilateral synchronous breast cancer during the 15-year period of 1984 through 1999 were reviewed. Information regarding age, mode of detection, histopathologic features, treatment, and overall survival were analyzed.

RESULTS

During the study period, 51 patients (all women) were treated at our institution for bilateral synchronous breast cancer. This comprised 2.1% of all patients (n = 2382 patients) treated for breast cancer during the same period of time. The first cancer was detected by palpation in 81% and by mammography in 14%. The corresponding figures for the contralateral cancer were 24% and 54%, respectively. The histologic type of cancer was identical in the 2 breasts in 29 patients (57%) and was different between the 2 breasts in 22 patients (43%). The overall 10-year survival rate was 63%.

CONCLUSIONS

Bilateral synchronous breast cancer is often detected by mammography and is frequently of the same histologic type as the index cancer. A better awareness of the risk for this disease may help detect bilateral breast cancer earlier.