Appearance of untreated bone metastases from breast cancer on FDG PET/CT: importance of histologic subtype

Abstract

Purpose Determine if the histology of a breast malignancy influences the appearance of untreated osseous metastases on FDG PET/CT. Methods This retrospective study was performed under IRB waiver. Our Hospital Information System was screened for breast cancer patients who presented with osseous metastases, who underwent FDG PET/CT prior to systemic therapy or radiation from 2009–2012. Patients with invasive ductal carcinoma (IDC), invasive lobular carcinoma (ILC), or mixed ductal/lobular (MDL) histology were included. Patients with history of other malignancies were excluded. PET/CT was evaluated, blinded to histology, to classify osseous metastases on a per patient basis as sclerotic, lytic, mixed lytic/sclerotic, or occult on CT, and record SUVmax for osseous metastases on PET. Results 95 patients met inclusion criteria (74 IDC, 13 ILC, and 8 MDL). ILC osseous metastases were more commonly sclerotic and demonstrated lower SUVmax than IDC metastases. For all IDC and MDL patients with osseous metastases, at least one was FDG-avid. For ILC, all patients with lytic or mixed osseous metastases demonstrated at least one FDG-avid metastasis; however, only 3 of 7 patients with sclerotic osseous metastases were apparent on FDG PET. Conclusions The histologic subtype of breast cancer affects the appearance of untreated osseous metastases on FDG PET/CT. In particular, non-FDG-avid sclerotic osseous metastases were more common in patients with ILC, than in those with IDC. Breast cancer histology should be considered when interpreting non-FDG-avid sclerotic osseous lesions on PET/CT, which may be more suspicious for metastases (rather than benign lesions) in patients with ILC.

Initial Results of a Prospective Clinical Trial of 18F-Fluciclovine PET/CT in Newly Diagnosed Invasive Ductal and Invasive Lobular Breast Cancers

“…Invasive lobular carcinoma (ILC), a subtype of breast cancer, is difficult to visualize by all known imaging modalities (9,10), including 18 F-FDG PET (11)(12)(13)(14)(15)(16). Thus, there is a continued need for the development of better metabolic imaging agents for breast cancer, particularly for ILC.…”

Prospective Clinical Trial of 18F-Fluciclovine PET/CT for Determining the Response to Neoadjuvant Therapy in Invasive Ductal and Invasive Lobular Breast Cancers

“…In this prospective trial, we evaluated 18 F-fluciclovine as a noninvasive biomarker of the tumor response after therapy but not as an early predictor of the tumor response. ILC, a subtype of breast cancer that accounts for 10%-15% of primary breast malignancies (28), is difficult to visualize by all current imaging modalities (14,15), including 18 F-FDG PET (17,18,20,21). Therefore, the development of better metabolic imaging agents for ILC could be clinically valuable.…”

“…Patients who presented for evaluation at Memorial Sloan Kettering Cancer Center; who had biopsyproven, locally advanced, nonmetastatic invasive ductal breast cancer (IDC) or invasive lobular breast cancer (ILC); and who were referred for neoadjuvant systemic therapy between August 2013 and August 2015 were invited to participate. ILC is a subtype of breast cancer that is difficult to visualize by all known imaging modalities (14,15), including 18 F-FDG PET (16)(17)(18)(19)(20)(21). Given the continued need for better metabolic imaging agents for ILC, patients with ILC were actively sought for inclusion in the study, accounting for the higher prevalence of ILC in our cohort than in the overall breast cancer population.…”

Imaging Bone Metastases in Breast Cancer: Staging and Response Assessment

“…Metastases that are inherently more biologically aggressive may show higher 18 F-FDG uptake, with patients having a shorter overall survival than those with osteoblastic disease (17). The underlying histologic subtype may also be important; untreated invasive lobular carcinoma has been reported to show osteoblastic metastases with poor 18 F-FDG uptake more frequently than invasive ductal or mixed subtypes (56). Previous treatment history is also important, as many 18 F-FDG-negative skeletal metastases may appear sclerotic as a consequence of previous successful systemic therapy, rendering tumor cells nonviable-even though ongoing reparative osteoblastic activity, as seen with BS or 18 F-NaF PET, may persist (57).…”