483 - A 90-YEAR-OLD WOMAN WITH INVASIVE LOBULAR CARCINOMA SUCCESSFULLY TREATED WITH CHEMOTHERAPY: A CASE REPORT

Abstract

Invasive lobular carcinoma is the second most common type of invasive breast cancer. Specific information regarding
its gold standard treatment is still very sparse, especially in older patients aged 80 years or more, or in more severe cases.
Therefore, studies that show this tumor’s response to different kinds of treatment are still very necessary. A 90-year-old
female patient, G5P4A1, with a familiar history of breast cancer (mother and sister), presented in March 2019 with a suspicious nodule on the right breast, measuring 2.6×1.9 cm at the physical examination. There were no palpable lymph nodes.
Further investigation with ultrasound (US) showed an irregular solid hypoechoic nodule measuring 2.9×2.3 cm on the
right breast, BI-RADS 6. Anatomopathological examination revealed an invasive lobular carcinoma; histologic grade II
and an immunohistochemistry report indicated the expression of hormone receptors (ER+ 80%, PR+ 70%) and a cell proliferation rate (Ki-67) of 10%, whereas there was no expression of HER2. Clinical staging was T2N0MX (inoperable stage
IIa). The patient then started chemotherapy with Fulvestrant + Denosumab in April 2019, with 10 sessions of this combined regimen (in April 2019, July 2019, August 2019, September 2019, November 2019, December 2019, September 2020,
November 2020, December 2020, and January 2021), which was switched in 6 months (in April 2019, May 2019, June 2019,
January 2020, August 2020, and October 2020) to sessions of a Fulvestrant-isolated regimen. The nodule size was evaluated with US throughout the treatment, showing constant regression: 2.2×1.8 cm (June 2019), 1.84×1.05 cm (July 2019),
and 0.8×0.7 cm (September 2019 and August 2020). The chemotherapy sessions ended in January 2021, when she also had
her last medical evaluation. The newest US she brought on that occasion showed that the solid nodule referred to in the
most recent previous examination on the right breast had no current US expression (BI-RADS 1). The patient exhibited
an excellent response to the chemotherapy. Hence, this form of treatment emerges as a valid and useful tool in the therapeutic management of invasive lobular carcinoma.