Univariate analysis for overall survival revealed that age y
Univariate analysis for overall survival revealed that age (≤, >50 years), menopausal status, T-N stage, and histological tumor size were statistically significant factors for survival. Menopausal status was determined after two years of amenorrhea. In post-menopausal women, the disease-free survival rate was better histological tumor size was smaller than 20 mm, and lymph nodes were not involved with statistical significance (Table 2).
Discussion PMBC is an uncommon type of carcinoma with a prevalence of 1–7% of all breast cancers, and usually occurs in patients aged 75 years or older. In western countries the incidence of PMBC in women under 35 years is only 1%. In our series, nine (16%) patients were younger than 35 years of age and the youngest patient was 20 years old at diagnosis. The reason for this difference is unclear, but it might be due to the breast screening policy, as well as genetic and environmental factors in western countries. The size of PMBCs at the time of diagnosis is subject to wide variation. This entity is a slow-growing tumor, with an estimated growth rate of one-third compared to invasive ductal carcinoma. The mean tumor size in the present study was 5 cm. This important measure, typically revealed by mucin volume, contributes to an overestimation of tumor size. The majority of patients (37/56, 66%) presented at stage T1 or T2, supporting the (+)-MK 801 Maleate that this cancer displays indolent behavior. Previous study has shown that no correlation exists between tumor size and prognosis because the tumor size largely depends on the volume of extracellular mucin. According to the statistical analysis, clinical and histology tumor size were a significant prognostic factor in our study. Mucinous carcinomas have been reported to have imaging characteristics that may mimic benign lesions, including a well-circumscribed margin and absence of micro-calcification. However, micro-calcifications have been reported in just a few studies, with an incidence of 5%–22%. The characteristic mammographic feature of the majority of the tumors in the present study was a well-circumscribed mass with a lobulated margin, and only 9% of the tumors showed micro-calcifications. The magnetic resonance features of PMBC seemingly combine benign (homogenous intensity on T1-weighted imaging [WI] and T2-WI, persistent enhancement pattern) and malignant traits (rim or heterogeneous enhancement). Compared with other benign and malignant lesions, mucinous carcinoma display a markedly high apparent diffusion coefficient (ADC). PMBCs have more favorable clinic-pathologic characteristics than invasive ductal carcinomas. In our study, PMBC had a lower histologic grade, less lymph-vascular invasion, higher hormonal receptor expression and less HER/neu gene overexpression. Previous studies found that although PMBC tumor size can become quite large, this may potentially have little effect on survival because the tumor size primarily depends on extracellular mucin volume. In our data, the AJCC system tumor size is not a significant risk factor, but histologic tumor size was a significant prognostic factor for overall survival and disease-free survival. Axillary metastases are rare, though generally found in 12–14% in most series studies. In our study, the data showed a rate of nodal involvement in 27.4% of the cases; however, this rate may be explained by a higher clinical tumor size (>54 mm). Paramo et al. reported that axillary lymph node staging in these patients might not be necessary because PMBC appears unlikely to metastasize. The presence of lymph node metastases strongly indicates the presence of a mixed mucinous carcinoma. Anan et al. have suggested that patients with PMBC, except for those cases involving invasion of the local skin, are suitable candidates for breast-conserving therapy, probably even in the presence of large tumors up to 5 cm in diameter. In our series no patient with tumor size <4 cm had lymph node metastasis. Therefore, we can consider the sentinel-lymph node biopsy in this case.