Differences in clinicopathological features and molecular phenotype of breast carcinoma between patients younger than 40 years and those who are older: A study from Pakistan

Background The debate whether breast cancer in women under 40 years of age is distinct from breast cancer in women above 40 is still inconclusive with various published studies providing conflicting evidence. The majority of studies however suggest that breast cancer in younger women (< 40) is more aggressive with worse clinicopathological features. However, the issue is by no means settled and a number of studies are still going on. Our objective was to analyze different clinicopathological variables and determine whether statistically significant differences are present between those under 40 and those above 40 years of age. The present paper contributes to this debate by reporting our findings. Methods Descriptive cross sectional study of 482 breast cancer cases reported between January and December 31, 2016 which included 380 patients (above 40 years of age) and 102 (under 40 years of age). Variables included grade, stage, axillary lymph node metastases, lymphovascular invasion and molecular groups. p-value less than 0.05 was taken as significant. Results Over 21% patients were younger than 40 years. Differences in histologic grade, stages of T1, T2, and T4, Estrogen Receptor (ER) and Progesterone Receptor (PR) status, Her2neu status, triple negativity and molecular groups between patients younger than 40 years and those older than 40 years were statistically insignificant. Differences in stage T3, axillary metastases and lymphovascular invasion were statistically significant. Conclusion Statistically significant differences were noted in some clinicopathological variables. Majority of variables indicating more aggressive disease were seen in patients older than 40 years of age. Additional studies with larger number of patients under 40 years of age are required to resolve the issue conclusively so that young women with breast cancer are not treated too aggressively unless there is unequivocal statistical evidence that breast cancer is more aggressive in patients under 40 years of age.