Prognostic parameters of luminal A and luminal B intrinsic breast cancer subtypes of Pakistani patients

Background

Prognosis of breast cancer and success of therapeutic interventions largely rely on the clinico-pathologic and biological characteristics of the tumor and vary due to the heterogeneous nature of breast cancers. The aim of this study was to determine the frequency and prognostic parameters of luminal breast cancers in our population to devise targeted and personalized therapeutic regimens tailored to the needs of the loco-regional population.

Methods

A retrospective cross-sectional study including 1951 cases of primary breast cancer treated at Liaquat National Hospital Karachi was conducted during the year 2011–2016. The clinico-pathologic characteristics were observed and semiquantitative immunohistochemical analysis was performed to study the luminal subtypes A and B. The cross-tabulated statistics of the observed characteristics were performed between the two subtypes. The significance level of each characteristic was estimated utilizing the chi-square test.

Results

Luminal cancers comprised 62.7% of the total number of cases diagnosed with breast cancers in the study period. Out of these 1224 cases of luminal cancers, 845 cases (69%) were luminal B, while 379 (31%) cases were of luminal A. Luminal B cancers were significantly more common in younger age groups as compared to luminal A cancers. Comparison of the two subtypes of luminal breast cancers revealed significant differences. Luminal B cancers were associated with higher grade (26% grade III in luminal B compared to 8% in luminal A), micropapillary histology, and high frequency of nodal metastasis (54 vs. 43%).

Conclusions

Luminal B comprised the most frequent subtype of breast cancer in our study and they were found more constantly in a younger age group. Moreover, they were associated with adverse clinico-histologic parameters like higher grade and nodal metastasis. Therefore, we suggest that, despite lack of widespread availability of molecular studies in our setup, IHC-based typing should be done in every case of breast cancer to individualize therapy.

The association of blunted nocturnal blood pressure dip and stroke in a multiethnic population

Nondipping has been defined as a reduction in the mean systolic and diastolic blood pressure (BP) of <10% from awake to sleep. We hypothesized that nondipping might be associated with stroke in minority populations. We monitored BP over a 24 h period with an ambulatory device in 166 cases from a multiethnic population of stroke survivors (63 blacks, 61 non-Hispanic whites, and 42 Caribbean Hispanics, aged 69.5 +/- 11 years) and 217 community control subjects (73 blacks, 107 non-Hispanic whites, and 67 Caribbean Hispanics, aged 69 +/- 9 years). Prevalence of nondipping was significantly greater among cases than among control subjects (64% v. 37%, P < .001). In a multiple logistic regression model adjusted for traditional risk factors for stroke, nondipping conferred an increased risk for stroke. Probability of stroke associated with nondipping (odds ratio (OR) 2.5, confidence interval (CI) 1.6 to 4.0) was equal to that of traditional risk factors. Nondipping increased the chance of having a stroke in both non-Hispanic whites (OR 4.2, P < .001) and blacks/Caribbean Hispanics (OR 1.9, P = .03). The strength of the contribution of nondipping to stroke risk was similar in all ethnic groups. Nondipping was associated with stroke in both men and women. Given the previous reports that nondipping contributes to stroke risk in European and Asian populations, these data suggest that nondipping may be universally associated with risk for stroke.

Clinicopathologic features of invasive metaplastic and micropapillary breast carcinoma: comparison with invasive ductal carcinoma of breast

Objectives

The aim of this study was to determine the frequency of metaplastic breast carcinoma and invasive micropapillary carcinoma in our population and also to compare the clinico-pathologic features of metaplastic breast carcinoma and invasive micropapillary carcinoma with invasive ductal carcinoma, not otherwise specified (IDC, NOS).

Results

86.9% of the cases were identified as ductal carcinoma, NOS, while 2.2% were metaplastic and 0.76% cases were micropapillary carcinoma. Metaplastic carcinomas were found to be of higher grade as compared to IDC, NOS as 81% of metaplastic carcinoma were grade III compared to 35% IDC, NOS. 79% of metaplastic carcinoma were ER negative and 86% were PR negative, respectively as compared to ductal carcinoma NOS, which were 40% ER negative and 54% were PR. Similarly, 86.7% micropapillary cancers were ER positive and 73.3% were PR positive. Moreover, 66.7% micropapillary carcinoma showed nodal metastasis and 77.8% showed lymphovascular invasion, which was significantly higher than that of IDC, NOS micropapillary and metaplastic carcinomas accounts for less than 2 and 1% of the breast cancer burden in our population and highly correlates with poor prognosis parameters therefore, require more intensive management in our population.

Clinical and prognostic profile of Her2neu positive (non-luminal) intrinsic breast cancer subtype: comparison with Her2neu positive luminal breast cancers

Objective

Her2neu receptor is proto-oncogene which can be over-expressed in both luminal and non-luminal breast cancers. In the present study, we aimed to compare the prognostic and predictive factors like tumor grade, T-stage, N-stage and ki67 index in Her2neu intrinsic breast cancer subtype with Her2neu over-expressed luminal breast cancers.

Results

801 (41%) cases were Her2neu positive; out of which, 418 cases (52.2%) showed ER positivity and thus were classified as Her2neu positive luminal cancers whereas 383 cases (47.8%) were ER and PR negative and therefore were labeled as intrinsic Her2neu subtype (non-luminal). Her2neu positive (non-luminal) cancers were significantly associated with higher grades and Ki67 proliferative index compared to Her2neu positive luminal cancers. On the other no significant association was noted in T-stage and N-stage. We found a high frequency of her2neu positivity in our studied population of breast cancer. Moreover, association of her2neu positive (non-luminal) breast cancers with higher grade and ki67 index indicates a predictive value of ER/PR positivity in her2neu positive breast cancers. On the other hand, lack of association with respect to T and N stage, signifies no prognostic benefit of ER/PR in her2neu positive breast cancers.