The prognosis of synchronous and metachronous bilateral breast cancer in Chinese patients

Clinical characteristics and prognostic analysis of metachronous bilateral breast carcinoma: a retrospective study based on propensity score matching

BACKGROUND

To investigate clinical characteristics, treatment, outcomes, and prognostic risk factors of metachronous bilateral breast carcinoma (MBBC) and provide a theoretical basis for clinical management of MBBC.

METHODS

This was a retrospective study. From January 1, 2010 to March 31, 2022, a total of 23,010 patients with breast cancer underwent surgical treatment at the Breast Center of the Fourth Hospital of Hebei Medical University, including 386 patients with MBBC. Propensity score matching (PSM) was performed on MBBC patients and unilateral breast cancer (UBC) patients in a 1:1 ratio, and 210 UBC patients and 210 MBBC patients were finally matched. Clinical medical records of all patients were collected, including age of onset, family history of breast cancer, tumor size, lymph node status, TNM stage, mode of surgery, menstruation, pathological type, immunohistochemical (IHC) typing, treatment, disease-free survival (DFS), and overall survival (OS).

RESULTS

The result showed that age of onset of the second primary cancer (SPC) was significantly older than that of the first primary cancer (FPC) (P = 0.024). Baseline data from MPPC patients showed that the tumor size of FPC was significantly larger than that of SPC (P = 0.043), and the proportion of PR ( +) in FPC is significantly higher than that in SPC (P = 0.045). Among MBBC patients with FPC for estrogen receptor (ER) or progesterone receptor (PR) ( +) and Her-2 (-), clinical characteristics and treatment results showed that the proportion of PR ( +) in the drug-resistant group was significantly lower than that in the non-drug-resistant group. The 2-year OS rate of SPC in the drug-resistant group was significantly shorter than those of the non-drug-resistant group (78.9% vs 100%, P < 0.05). The result of PSM-based comparison between MBBC patients and UBC patients showed significantly lower proportion of MBBC patients with SPC received chemotherapy compared to UBC patients (P = 0.026), and there was no significant difference in OS and DFS between SPC course of MBBC patients and UBC patients (P > 0.05). The univariate analysis showed that high TNM stage was a risk factor for death and disease progression in MBBC patients, with the risk of death in stage III MBBC patients being about 5 times higher than that in stage I MBBC patients (HR = 4.97, 95%CI = 1.42-17.31, P = 0.012), and the risk of disease recurrence being about 3.5 times higher than that in stage I MBBC patients (HR = 3.55, 95%CI = 1.07-11.81, P = 0.039).

CONCLUSION

In summary, this study presented clinical characteristics, treatment options, and outcomes of MBBC patients and patients with MBBC who were resistant to endocrine therapy have a worse SPC survival prognosis. The course of SPC in MBBC patients was similar to that of UBC in terms of prognosis and survival, which suggested that SPC can be treated according to UBC treatment regimen. High TNM stage was a prognostic risk factor for SPC patients.

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.

Bilateral breast cancer in China: A 10-year single-center retrospective study (2006-2016)

Bilateral breast cancer (BBC) is an uncommon subset of breast cancer (BC), and it may present as synchronous bilateral breast cancer (sBBC) or metachronous bilateral breast cancer (mBBC). Through this study, we aimed to evaluate the proportion of BBC in BC and compare the clinicopathological characteristics, treatment, and outcomes of sBBC and mBBC at an academic cancer center in China. Patients with BC consecutively treated between 2006 and 2016 were retrospectively reviewed. Patients with BBC were included. In total, 3924 patients with BC were analyzed and 127 patients with BBC (28 sBBC, 99 mBBC) with a median follow-up of 98 months were identified. The proportion of BBC was 3.2% (0.7%, sBBC; 2.5%, mBBC). The median age at the first diagnosis of mBBC was significantly younger than that at the first diagnosis of sBBC (p = 0.027). Patients diagnosed as having sBBC were more likely to have a positive family history (p = 0.047). The first tumors of mBBC were detected at a significantly earlier tumor stage compared with those of sBBC (p = 0.028). The concordance rates of histopathologic type in the first and second tumors were 60.7% and 58.0% in sBBC and mBBC, respectively. sBBC had a significantly poorer disease-free survival than mBBC did (p = 0.001). BBC is a rare disease affecting the Chinese population. sBBC is associated with a greater prevalence of a family history of breast cancer and poorer prognosis, compared with mBBC.

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.

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.

Comparative genomic analysis reveals bilateral breast cancers are genetically independent

Bilateral breast cancer (BBC) poses a major challenge for oncologists because of the cryptic relationship between the two lesions. The purpose of this study was to determine the origin of the contralateral breast cancer (either dependent or independent of the index tumor). Here, we used ultra-deep whole-exome sequencing and array comparative genomic hybridization (aCGH) to study four paired samples of BBCs with different tumor subtypes and time intervals between the developments of each tumor. We used two paired primary breast tumors and corresponding metastatic liver lesions as the control. We tested the origin independent nature of BBC in three ways: mutational concordance, mutational signature clustering, and clonality analysis using copy number profiles. We found that the paired BBC samples had near-zero concordant mutation rates, which were much lower than those of the paired primary/metastasis samples. The results of a mutational signature analysis also suggested that BBCs are independent of one another. A clonality analysis using aCGH data further revealed that paired BBC samples was clonally independent, in contrast to clonal related origin found for paired primary/metastasis samples. Our preliminary findings show that BBCs in Han Chinese women are origin independent and thus should be treated separately.

A clinicopathological study of early-stage synchronous bilateral breast cancer: a retrospective evaluation and prospective validation of potential risk factors

Background

The aim of the present study was to investigate potential risk factors for synchronous bilateral breast cancer sBBC).

Methods

A retrospective analysis was performed of patients diagnosed and treated with operable bilateral breast cancer (BBC) between June 2007 and December 2011. Risk factors for sBBC were evaluated in this cohort and further validated in a prospective observational validation analysis of patients between January 2012 and December 2012. Patients treated with operable unilateral breast cancer during the same period were used as a control group.

Results

A total of 11,247 patients with primary breast cancer underwent operations at the Fudan University Shanghai Cancer Center between June 2007 and December 2012. The incidence of sBBC was 1.6%. The age at diagnosis (HR = 2.4, 95% C.I.: 1.4–4.0, p = 0.001), presence of sclerosing adenosis (HR = 11.8, 95% C.I.: 5.3–26.3, p<0.001), lobular carcinoma component involvement (HR = 5.6, 95% C.I.: 2.6–12.1, p<0.001), and family history of first-degree relatives with breast cancer (HR = 2.0, 95% C.I.: 1.1–3.4, p<0.001) were independent risk factors for sBBC. A subsequent validation study failed to confirm the significance of family history. No significant difference on survival was found between patients with early-stage sBBC and control cases.

Conclusions

Patients with the presence of sclerosing in the affected breast, and lobular carcinoma component involvement may be at high risk for developing sBBC. This study supports the hypothesis that the host-carcinoma biological relationship, especially for the tumor microenvironment, played a critical role in the carcinogenesis of sBBC.