Abstract 257P
Background
Relationships of parity with breast cancer risk are complex. Breast cancer expresses many molecular subtypes with different prognoses and etiology. Parity is associated with decreased risk of postmenopausal hormone receptor-positive breast tumours, however, it may increase the risk for basal-like subtype of breast cancers and early-onset tumours. Previous studies have shown that reproductive factors are differentially associated with breast cancer (BC) risk by subtypes. The aim of this study was to investigate associations between reproductive factors and BC subtypes, and whether these vary by age at diagnosis.
Methods
We have conducted a study of pregnant women with breast cancer attending the breast clinics in Tripoli, Libya from 2002 to 2017. The reproductive and surgical information was obtained from the records. Statistical analysis was done using SPSS 22.
Results
524 pregnant women was diagnosed with breast tumour in the period of 15 years. The mean age at onset was 34.9 +/-4 SD and ranged from 25 to 40 years, while the onset of menarche ranged from 10 to 16 years with mean of 11.3+/-1.48. Family history of breast cancer in 165 cases (31.5%). Only 3 cases presented with bilateral breast mass, while 266 (50.8%) had left breast mass and 254 (48.5%) in the right. Histopathology showed that 31 biopsies was grade I, 253 grade II and 209 grade III. Also, estrogen receptor was positive in 251 (47.9%) cases, progesterone positive in 228 (43.5%) and HERT-neu in 164 (31.3%). Regarding the molecular subtype, Basal-like was the most common one in 194 cases (37%), then Luminal A in 165 (31.5), Luminal B in 88 (16.8%), HER2-en positive in 74 (14.1%) respectively.
Conclusions
The cases presented with breast cancer during pregnancy have high rates of basal-like subtypes compared to previous reports. Further researches are needed to ascertain the relation between pregnancy and molecular subtype of breast cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
Tripoli University Hospital.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest..