Bilateral Breast Cancer After Multimodality Treatment: A Report of Clinical Outcomes in an Asian Population

Preoperative breast MRI positively impacts surgical outcomes of needle biopsy-diagnosed pure DCIS: a patient-matched analysis from the MIPA study

OBJECTIVES

To investigate the influence of preoperative breast MRI on mastectomy and reoperation rates in patients with pure ductal carcinoma in situ (DCIS).

METHODS

The MIPA observational study database (7245 patients) was searched for patients aged 18-80 years with pure unilateral DCIS diagnosed at core needle or vacuum-assisted biopsy (CNB/VAB) and planned for primary surgery. Patients who underwent preoperative MRI (MRI group) were matched (1:1) to those who did not receive MRI (noMRI group) according to 8 confounding covariates that drive referral to MRI (age; hormonal status; familial risk; posterior-to-nipple diameter; BI-RADS category; lesion diameter; lesion presentation; surgical planning at conventional imaging). Surgical outcomes were compared between the matched groups with nonparametric statistics after calculating odds ratios (ORs).

RESULTS

Of 1005 women with pure unilateral DCIS at CNB/VAB (507 MRI group, 498 noMRI group), 309 remained in each group after matching. First-line mastectomy rate in the MRI group was 20.1% (62/309 patients, OR 2.03) compared to 11.0% in the noMRI group (34/309 patients, p = 0.003). The reoperation rate was 10.0% in the MRI group (31/309, OR for reoperation 0.40) and 22.0% in the noMRI group (68/309, p < 0.001), with a 2.53 OR of avoiding reoperation in the MRI group. The overall mastectomy rate was 23.3% in the MRI group (72/309, OR 1.40) and 17.8% in the noMRI group (55/309, p = 0.111).

CONCLUSIONS

Compared to those going directly to surgery, patients with pure DCIS at CNB/VAB who underwent preoperative MRI had a higher OR for first-line mastectomy but a substantially lower OR for reoperation.

CLINICAL RELEVANCE STATEMENT

When confounding factors behind MRI referral are accounted for in the comparison of patients with CNB/VAB-diagnosed pure unilateral DCIS, preoperative MRI yields a reduction of reoperations that is more than twice as high as the increase in overall mastectomies.

KEY POINTS

• Confounding factors cause imbalance when investigating the influence of preoperative MRI on surgical outcomes of pure DCIS. • When patient matching is applied to women with pure unilateral DCIS, reoperation rates are significantly reduced in women who underwent preoperative MRI. • The reduction of reoperations brought about by preoperative MRI is more than double the increase in overall mastectomies.

Patient-derived organoid elucidates the identical clonal origin of bilateral breast cancer with diverse molecular subtypes

Bilateral breast cancer (BBC), an infrequent breast cancer subtype, has primarily been studied in terms of incidence, prognosis, and through comparative analysis of synchronous (SBBC) and metachronous (MBBC) manifestations. The advent and application of organoid technology hold profound implications for tumor research and clinical management. This study represents the pioneering use of organoid models in BBC research. We established organoid lines from two surgical tumor specimens of a BBC patient, with one line undergoing detailed pathological and genomic analysis. The BBC organoid from the right breast demonstrated a marker expression profile of ER (-), PR (-), HER-2 (0), and Ki67 index 10%, indicating that it may derived from the TNBC tissue. Whole Exome Sequencing (WES) displayed consistent set of Top10 cancer driver genes affected by missense mutations, frameshift mutation, or splice site mutations in three tumor tissues and the organoid samples. The organoids' single nucleotide polymorphisms (SNPs) were more closely aligned with the TNBC tissue than other tumor tissues. Evolutionary analysis suggested that different tumor regions might evolve from a common ancestral layer. In this case, the development of BBC organoids indicated that simultaneous lesions with diverse molecular profiles shared a high degree of consistency in key tumor-driving mutations. These findings suggest the feasibility of generating BBC organoids representing various molecular types, accurately replicating significant markers and driver mutations of the originating tumor. Consequently, organoids serve as a valuable in vitro model for exploring treatment strategies and elucidating the underlying mechanisms of BBC.

Bilateral Breast Cancer: Clinical Profile and Management

There is paucity of literature regarding the demography, histopathology, management, and outcomes of bilateral breast cancer (BBC). We present our experience of treating 127 BBC with multimodality management. An audit of prospectively maintained computerized breast cancer database of the department of surgical oncology at a tertiary care center was performed. Demography, clinical profile, molecular sub-types, treatment patterns, and outcomes were analyzed. A total 127 patients presented with BBC between 1992 and 2019. Ninety-four had metachronous (MBBC) and 33 had synchronous breast cancer (SBBC). Most contralateral breast cancer (CBC) patients had early-stage breast cancer in comparison to the index side cancer (37% vs 32%). Ninety-four patients underwent bilateral mastectomy and only 18 patients underwent bilateral breast conservation. Seventy-one patients undergoing BCS and surgery for LABC were given postoperative radiotherapy. All patients received adjuvant chemo- and/or hormonal therapy both for index and CBC based on the stage and hormone receptor status. Thirty-three percent of patients had either locoregional or distant relapse. The 5-year overall survival (OS) and 5-year disease-free survival (DFS) of the entire cohort were 86.6% and 68.4% respectively. There was no difference in the OS and DFS between SBBC and MBBC. The incidence of BBC is expected to increase with effective diagnostic and therapeutic interventions and improving survival. Patients require individualized treatment planning in a multidisciplinary treatment setting.

Contralateral Breast Screening with Preoperative MRI: Long-Term Outcomes for Newly Diagnosed Breast Cancer

Background The diagnostic value of screening the contralateral breast with MRI in patients with newly diagnosed breast cancer is poorly understood. Purpose To assess the impact of MRI for screening the contralateral breast on long-term outcomes in patients with newly diagnosed breast cancer and to determine whether subgroups with unfavorable prognoses would benefit from MRI in terms of survival. Materials and Methods Data on consecutive patients with newly diagnosed breast cancer seen from January 2008 to December 2010 were reviewed retrospectively. Patients with neoadjuvant chemotherapy, previous breast cancer, distant metastasis, absence of contralateral mammography at diagnosis, and no planned surgical treatment were excluded. Groups that did and did not undergo preoperative MRI were compared. Survival analysis was performed using the Kaplan-Meier method for propensity score-matched groups to estimate cause-specific survival (CSS) and overall survival (OS). A marginal Cox proportional hazards model was used to evaluate association of MRI and clinicopathologic variables with OS. Results Of 1846 patients, 1199 fulfilled the inclusion criteria. Median follow-up time was 10 years (range, 0-14 years). The 2:1 matched sample comprised 705 patients (470 in the MRI group and 235 in the no-MRI group); median ages at surgery were 59 years (range, 31-87 years) and 64 years (range, 37-92 years), respectively. MRI depicted contralateral synchronous disease more frequently (27 of 470 patients [5.7%] vs five of 235 patients [2.1%]; P = .047) and was associated with a higher OS (hazard ratio [HR], 2.51; 95% CI: 1.25, 5.06; P = .01). No differences were observed between groups in metachronous disease rate (MRI group: 21 of 470 patients [4.5%]; no-MRI group: 10 of 235 patients [4.3%]; P > .99) or CSS (HR, 1.34; 95% CI: 0.56, 3.21; P = .51). MRI benefit was greater in patients with larger tumor sizes (>2 cm) (HR, 2.58; 95% CI: 1.11, 5.99; P = .03) and histologic grade III tumors (HR, 2.94; 95% CI: 1.18, 7.32; P = .02). Conclusion Routine MRI screening of the contralateral breast after first diagnosis of breast cancer improved overall survival; the most pronounced benefit was found in patients with larger primary tumor size and primary tumors of histologic grade III. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Taourel in this issue.

A Retrospective Study on the Clinicopathologic Characteristics and Outcomes of 179 Cases of Synchronous and Metachronous Bilateral Breast Cancer in China

OBJECTIVE

To investigate the clinicopathologic characteristics and outcome of bilateral breast cancer (BBC) in the Chinese population.

METHODS

A retrospective study was conducted on 7797 cases with primary breast cancer, including 7618 cases of unilateral breast cancer (UBC) and 179 cases of BBC. Among the latter, there were 108 cases of synchronous BBC (SBBC) and 71 cases of metachronous BBC (MBBC).

RESULTS

In the present study, the incidence of SBBC and MBBC are 1.39% and 0.91% among the general population, respectively. In comparison of UBC and BBC, SBBC and MBBC, there are significant differences in the common clinicopathological characteristics, such as pathologic stage, hormone receptor (HR) status and molecular type. In respect of the surgical treatment of BBC, 49.72% of the patients chose mastectomy. The 3-year disease free survival (DFS) for SBBC and MBBC are 94.4% and 96.9%, respectively. There is no difference in the overall survival (OS) and DFS between SBBC and MBBC. The histological grade and type of surgery on tumors of both sides are important influencing factors of DFS in the BBC patients.

CONCLUSION

There are statistical differences in the clinicopathological characteristics and outcomes between SBBC and MBBC among the Chinese population. Therefore, the treatment of BBC patients should be individualized.

Association of molecular subtype concordance and survival outcome in synchronous and metachronous bilateral breast cancer

Background

The aim of this study was to analyze the association of molecular subtype concordance and disease outcome in patients with synchronous bilateral breast cancer (SBBC) and metachronous breast cancer (MBBC).

Patients and methods

Patients diagnosed with SBBC or MBBC in the Surveillance, Epidemiology, and End Results (SEER) database or Comprehensive Breast Health Center (CBHC) Ruijin Hospital, Shanghai were retrospectively reviewed and included. Clinicopathologic features, molecular subtype status concordance, and prognosis were compared in patients with SBBC and MBBC. Other prognostic factors for breast cancer-specific survival (BCSS) and overall survival (OS) were also identified for bilateral breast cancer patients.

Results

Totally, 3395 and 115 patients were included from the SEER and Ruijin CBHC cohorts. Molecular subtype concordance rate was higher in the SBBC group compared to MBBC in both SEER cohort (75.8% vs 57.7%, p < 0.001) and Ruijin CBHC cohort (76.2% vs 45.2%, p = 0.002). Survival analyses indicated that SBBC was related to worse BCSS than MBBC (p = 0.015). Molecular subtype discordance was related to worse BCSS (hazard ratio (HR), 1.64, 95% confidential interval (CI), 1.18–2.27, p = 0.003) and OS (HR, 1.59, 95% CI, 1.24–2.04, p < 0.001) in the SBBC group, but not for the MBBC group (p = 0.650 for BCSS, p = 0.669 for OS).

Conclusions

Molecular subtype concordance rate was higher in the SBBC group than MBBC group. Patients with discordant molecular subtype was associated with worse disease outcome in the SBBC patients, but not in MBBC, which deserves further clinical evaluation.

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SBBC was associated with higher concordance rates of ER, PR, HER2, and molecular subtype status compared to MBBC.

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SBBC had worse BCSS than MBBC.

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Molecular subtype discordance was independently related to worse prognosis in SBBC but has no impact on prognosis of MBBC.

The prognostic comparison among unilateral, bilateral, synchronous bilateral, and metachronous bilateral breast cancer: A meta-analysis of studies from recent decade (2008-2018)

Background

The incidence of bilateral breast cancer (BBC) is increasing nowadays comprising 2%‐11% of all breast cancer (BC). According to the interval time between the first and second cancer, BBC could be divided into synchronous (SBBC) and metachronous (MBBC). However, this interval time is quite different across studies. It remains controversial whether the survival of BBC, SBBC, and MBBC is similar or worse compared to that of unilateral breast cancer (UBC), and whether the survival of SBBC is similar or worse compared to MBBC. To better understand the survival of UBC, BBC, SBBC, and MBBC and how the interval time would influence the prognosis of SBBC and MBBC, we performed this meta‐analysis on studies from recent 10 years (2008‐2018).

Methods

Databases of PubMed, Embase, and Web of Science were searched for relevant studies within recent 10 years. Hazard ratio (HR) was adopted to evaluate the difference of overall survival (OS) of UBC, BBC, SBBC, and MBBC. HR of OS comparisons were performed between BBC vs UBC, SBBC vs UBC, MBBC vs UBC, and SBBC vs MBBC with 3, 6, 12 months as the interval time, respectively.

Results

There were 15 studies of 72 302 UBC and 2912 BBC included in the meta‐analysis. The summary HR of OS comparison between BBC vs UBC was 1.68 (95% CI: 1.28‐2.20), SBBC vs UBC was 2.01 (95% CI: 1.14‐3.55), MBBC vs UBC was 3.22 (95% CI: 0.75‐13.78). When 3, 6, 12 months were used as the interval time, the summary HR of the OS comparison between of SBBC vs MBBC were 0.64 (95% CI: 0.44‐0.94), 1.17 (95% CI: 0.84‐1.63) and 1.45 (95% CI: 1.10‐1.92), respectively.

Conclusion

BBC and SBBC showed worse prognosis in terms of OS compared to UBC while MBBC manifested similar or non‐superior survival as UBC. The OS comparison between SBBC and MBBC changed with different interval time used. The longer the interval time used, the worse the survival of SBBC. SBBC with interval of 3‐12 months between the two cancers had the worst prognosis. When 6 months was used to differentiate SBBC from MBBC, these two clinical entities showed similar OS.