Precursor lesions and prognosis-related clinicopathological characteristics of breast mucinous carcinoma
Purpose To analyze the precursor lesions,clinicopathological features and prognosis of mucinous carcinoma(MC).Methods A total of 303 MC cases diagnosed by surgi-cal specimens were included,including 193 pure mucinous car-cinomas(PMC)and 110 mixed mucinous carcinomas(MMC).PMC included 163 cases of type A(hypocellular type)and 30 cases of type B(hypercellular type).The histomorphological characteristics,surrounding breast tissue morphology,and im-mune markers were evaluated to analyze the clinicopathological features related to MC precursor lesions and prognosis.Results The median age at diagnosis of MC was 50 years,and the me-dian tumor size was 2.5 cm.Compared to PMC,MMC had more lymph node(LN)involvement,more grade Ⅲ-Ⅳ and Ki67>20%tumors(P<0.05).There were no significant differences in tumor size,LN involvement and clinical stage between type A and type B PMC.55 cases of MC(49 PMC and 6 MMC)with precursor lesions of mucocoele-like lesions(MLL)were all grade 1 to 2,most of them(54/55,98.2%)were T1-T2,and the proportions of MC component in all 6 MMCs were all ≥ 50%.There were 119 cases of MC whose precursor lesions were ductal carcinoma in situ(DCIS),of which 28.6%of cases(34/119)had LN involvement,and 16.8%(20/119)of cases showed high proliferative activity(Ki67>20%).The precursor lesions of MC in 16 cases were solid papillary carcinoma(SPC)in situ,inclu-ding 7 cases of type BPMC and 9 cases of MMC.The median age of these patients was 67 years and no recurrence or metastasis was observed during follow-up.The disease-free survival(DFS)and overall survival(OS)of the 303 cases of MC was 93.5%and 98.6%,respectively.PMC had a better prognosis than MMC(DFS:95.2%vs.90.6%;OS:99.5%vs.97.2%),but there was no significant difference between type A and type B PMC.The prognosis of patients with LN involvement and clinical stage Ⅲ-Ⅳ was worse(P<0.05).Conclusion MC of the breast is a kind of heterogeneous malignant tumors.Our findings support that MC with specific precursor lesions have different ev-olutionary pathways,that MC with precursor lesions of MLL and SPC have a good prognosis,and MC associated with high-grade DCIS are more aggressive.LN involvement,higher clinical grade,and younger age are associated with poor prognosis.Focu-sing on precursor lesions and high risk clinicopathological fea-tures can contribute to providing more effective treatments for these patients.
breast neoplasmmucinous carcinomaprecursor le-sionsprognosis