IDC didn't show up on PET scan?

[greenacres]

I have a question. I had a full PET scan prior to my surgery (partial mast) last December. I received a copy of the report shortly thereafter. There was no indication of any cancer in my breast (no uptake), in fact, no mention of my breasts at all. It said there was uptake here and there, but nothing of concern (in my sacroiliac joints and my nasopharynx). Why if I had/have cancer in my left breast, a 1.7 cm size tumor, it wouldn't have seen it? I'm just curious.

Of course, the biopsy did reveal IDC, 3 nodes, clean, er-/pr- and her2+++. Some DCIS along with IDC and very close the margin some lobular hyperplasia (which scares me too because it sounded like this was left in my breast and they said "Chemo would take care of that". Thanks!

[Jackie07]

Found this article from PubMed. It's dated (2001) but I think the content is still valid and that's probably why there's no new report on the subject.


Semin Roentgenol. 2001 Jul;36(3):250-60.
Current status of PET in breast cancer imaging, staging, and therapy.

Wahl RL.
Division of Nuclear Medicine, Johns Hopkins Medical Institutes, Baltimore, MD 21287, USA.

The exact roles of PET in the imaging management of patients with known or suspected breast cancer are still in evolution. For assessing primary lesions, it is sometimes possible with PET to detect cancers occult on standard methods. This could be useful in high-risk patient populations, but in dense breasts, background FDG uptake is often higher than in women with fatty breasts, making identification of lesions < 1 cm in size improbable with current technologies. Distinguishing malignant from benign primary breast disease would seem better addressed by biopsy. With a positive predictive value of FDG PET for cancer over 96%, any FDG-avid breast lesion is highly suspicious and merits biopsy. Although PET in theory should be useful for depicting multifocal disease before surgery, the limitations in detecting small lesions in the breast limit the contribution of PET at present. It is most likely that PET will have a greater role in depicting primary breast lesions as dedicated PET imaging devices for the breast evolve. For axillary and internal mammary nodal staging, results with FDG PET are variable. Small nodal metastases < or = 5 mm will be missed by PET, whereas larger ones are more likely to be detected. PET can depict internal mammary nodes, but the accuracy of the method in this setting is not known, nor is there consensus on how identifying internal mammary node metastases will change treatment. Based on the available data, for pT1 breast lesions, PET, if negative, is not an adequate replacement for sentinel node surgery or axillary dissection. Results from the multicenter trial will be of great interest. Clearly PET can stage metastatic disease well. Bone scans with 18F- are exquisitely sensitive for metastases, and FDG is also very good. However, FDG PET can miss some blastic metastases to bone so at present FDG is not capable of excluding the presence of bone metastases. PET seems very well suited to detecting recurrences in soft tissues and the brachial plexus region in particular. The utility of PET in planning the treatment of individual patients appears promising. Although results must be confirmed in larger studies, it appears safe to conclude that failure of a chemotherapy regimen to decrease FDG uptake promptly in a breast cancer portends poor response. This does not hold true for hormonal therapy. At present, labeled estrogens are not widely available and cannot be recommended for clinical use. Thus, PET has shown considerable promise in breast cancer imaging, but in the author's experience is best applied to solve difficult imaging questions in specific patients and is not recommended for routine evaluation of the breast cancer patient. However, in larger primary tumors, the ability to use PET for staging and to plan treatment response suggest it will be more widely used. Additional studies with newer PET imaging devices and FDG and other tracers will help us better determine the role of PET in routine clinical care of the patient with known or suspected breast cancer. Certainly, this represent a fertile area for translational research studies over the next several years with the potential to significantly alter the way breast cancer is imaged and managed.
PMID: 11475071 [PubMed - indexed for MEDLINE]

[Jackie07]

Cancer Imaging. 2010 Jul 6;10:144-52.

Opportunities for PET to deliver clinical benefit in cancer: breast cancer as a paradigm.

Fleming IN, Gilbert FJ, Miles KA, Cameron D.
Aberdeen Biomedical Imaging Centre, University of Aberdeen, Aberdeen, UK.
Abstract

The glucose analogue fluorodeoxyglucose (FDG) has demonstrated enhanced uptake in the majority of tumours as a result of increased uptake and fixation by phosphorylation. It is the most widely used radiotracer in positron emission tomography (PET), being used in >90% of scans, and is useful for diagnosis, staging and detection of residual/recurrent cancer. However, there are limits to the utility of FDG, particularly in certain tumour types. The development of new radiotracers to study molecular processes such as proliferation, apoptosis, angiogenesis and hypoxia will complement FDG by providing additional information on the cell biology of tumours. The aim of this paper is to consider how the availability of new tracers, or new applications for existing PET/CT technologies, could deliver clinical benefit in cancer, using breast cancer as a paradigm.

PMID: 20605761 [PubMed - in process]