Introduction: Early onset breast cancer (occuring under age 40) tend to exhibit a different, aggressive phenotype, and are usually associated with hereditary BRCA1 or BRCA2 mutations. We investigated the levels of Hsp27 and HER2/Neu, as well as ER positivity, in early onset breast cancer patients.
Materials and methods: Eighteen paraffin blocks of tissues from patients diagnosed with invasive ductal carcinoma of no specific type (IDC-NST) regardless of grade or stage, age below 39 years (mean 34 years) who underwent surgery or surgical biopsy in Dr. Soetomo General Hospital, Surabaya, within the period of January 2014 - December 2014, were examined for Hsp27 expression, estrogen receptor status, and HER2/Neu amplification. The control group consisted of blocks from 112 patients diagnosed with IDC-NST aged older than 40 who underwent resection within the same period; all specimen in the control group is also stained for Hsp27 and tested for ER and HER2/Neu status.
Results: Examined blocks gained from the younger patient pool typically has higher grade, were negative for estrogen receptor status and show less Hsp27 expression. Sixteen (88.9%) of early-onset patients has grade II or III cancer, with 55.55% presenting with grade III cancer. Meanwhile, 79 (70.53%) of late onset patient has grade II or III cancer, with 26.78% presenting with grade III cancer. Seventy-seven out of 112 (68.75%) patients aged 50 or older has positive ER status, while only 8 out of 18 (45.45%) of early-onset patients have positive ER status. All patients aged 50 years and below show Hsp27 score that is less than the median score, while from all patients aged 50 or above, 64 out of 96 (66.66%) samples exceed the median score. Meanwhile, HER2/Neu scoring distribution seem to be similar across age groups.
Conclusion: Difference in estrogen receptor expression and Hsp27 levels show a significant difference between early-onset and late-onset breast cancer patients. Meanwhile, HER2/Neu amplicafication shows similarities between early-onset and late-onset patients
