Abstract:
Objectives: To compare the risk factors and clinico-pathological features of Triple
Negative Breast Cancer (TNBC) and non-TNBC in females in Southern Province of Sri
Lanka
Methods: This retrospective study included all breast cancer patients who had sought
the immunohistochemistry services at our unit from May 2006 to December 2012. The
tumours which were completely negative for ER, PR (Quick score = 0) and Her-2
expression of 0 and 1+ were considered TNBC. Tumour grading and assessment of ER,
PR and Her-2 were done by the principal investigator. The laboratory records and a pre tested, interviewer-administered questionnaire were used to collect data. The Chi-square
test was used to determine the statistical significance.
Results: This study enrolled 944 breast cancer patients (269=TNBC, 532= Non-TNBC
and 143= unknown). The patients with TNBC presented at a younger age (p=0.043) with
high grade (χ2 trend<0.001), larger tumours (χ2 trend=0.007), with higher Nottingham
prognostic index (χ2 trend=0.003) and no associated DCIS (p=0.015) compared to the
non-TNBC. There was no significant difference between TNBC and non-TNBC with
regard to the grade of DCIS, pathological stage, lymph node metastasis and presence of
LCIS, Paget’s disease and lympho-vascular invasion. There was no significant difference
between TNBC and non-TNBC with regard to any of the risk factors of breast carcinoma
assessed.
Conclusions: The poor prognosis of TNBC can be explained by its unique features
including younger age at presentation and associated unfavourable histopathological
features. There is no significant difference between the two groups with regard to the
associated risk factors.
