Oxygenation gain factor: a novel parameter characterizing the association between hemoglobin level and the oxygenation status of breast cancers

Tumor hypoxia has been linked to acquired treatment resistance, tumor progression, and poor prognosis. Because anemia is a major causative factor for the development of hypoxia, the association between blood hemoglobin concentration (cHb) and breast cancer oxygenation was examined in this study. In addition, a novel parameter characterizing the relationship between oxygenation status and rising cHb is introduced: the oxygenation gain factor (OGF). In breast cancer patients, median cHb over the range 8.5-14.7 g/dl correlated positively with the median pO(2) (3-15 mm Hg), yielding an average OGF of 2 mm Hg.dl/g. In contrast, in normal tissues (normal breast, subcutis, and skeletal muscle) the median pO(2) values were substantially higher (52 mm Hg, 51 mm Hg, and 37 mm Hg, respectively) and remained constant irrespective of the hemoglobin level over the range from 10 to 16 g/dl (OGF = 0 in grade I anemia and nonanemic patients). Moderately lower median pO(2) values in subcutis and skeletal muscle were only observed in grade II anemia (8 g/dl < cHb < or =10 g/dl), although this would appear to be of no biological relevance. Conversely, in breast cancers, even mild anemia (grade I anemia) is a major causative factor for the development of hypoxia or anoxia.

Hypoxia in breast cancer: pathogenesis, characterization and biological/therapeutic implications

Nearly 50% of locally advanced breast cancers exhibit hypoxic and/or anoxic tissue areas that are heterogeneously distributed within the tumour mass. Hypoxia is predominantly caused by structural and functional abnormalities of the newly formed tumour vessels arising from neovascularization, by a disturbed microcirculation, by enlarged diffusion distances, and by tumour-associated or therapy-induced anaemia. The extent of pretherapeutically measured hypoxic tissue areas is independent of clinical tumour size and stage, and histological type and grade. Anaemia can substantially worsen tumour O2 depletion. Hypoxia is known to directly or indirectly confer resistance to irradiation and some chemotherapeutic drugs leading to treatment failure. Sustained tumour hypoxia also gives rise to a more malignant phenotype (malignant progression). Due to this association between tumour hypoxia, malignant progression and treatment failure, tumour oxygenation has proven to be an independent, powerful prognostic factor for local control, overall and disease-free survival. Pretreatment assessment of tumour hypoxia is therefore needed to allow the selection of patients for more aggressive treatment within clinical trials or for individualization of therapy, and to identify patients who could benefit from hypoxiatargeting treatment measures. Due to a relatively high risk of relapse, patients with hypoxic tumours should undergo close surveillance. Anaemia in cancer patients should be prevented/corrected in order to improve radio-/chemosensitivity and thus to increase cancer cure rates.

[MR-guided preoperative localization and percutaneous core biopsy of suspected breast lesions. Possibilities and experience on the vertically open 0.5-T-system]

PURPOSE

To evaluate the feasibility of performing breast interventions in a vertically open 0.5 T MR system (SIGNA SP/i, GE Medical Systems). To develop fitted equipment and to establish preoperative wire localization and percutaneous breast core biopsy as clinical routine procedures.

PATIENTS AND METHODS

Initially, we applied a localization method with the patient placed in a sitting position in 31 cases using a single loop coil and a self-developed fixation device. Subsequently, 46 wire localizations and 28 percutaneous core biopsies were carried out in prone patient position using an open breast coil with an integrated biopsy device. The used instruments were either MR-compatible (18 G biopsy needle and localization wire, 14 G coaxial needle, prototype of a 16 G double-shoot gun) or MR-safe (double-shoot gun with 16 G needle).

RESULTS

After biopsy we found the needle tip (18 G for a wire localization and 14 G for a percutaneous core biopsy, respectively) placed either within or close to the lesions (< 10 mm distance) for all patients. Out of a total of 66 benign lesions and 39 malignant tumors we missed the lesion (12 mm mean diameter, 4-25 mm range) during open biopsy in two cases and obtained a false negative result for one percutaneous biopsy of a 5 mm lesion.

CONCLUSION

Preoperative wire localization and percutaneous core biopsy of suspicious breast lesions demonstrated by MRI can be carried out a vertically open 0.5 T MR scanner. The degree of accuracy is comparable with that of X-ray or ultrasound-guided procedures. A follow-up has to be performed in cases with a negative biopsy.

Metastasizing signet ring cell carcinoma of the stomach-mimicking bilateral inflammatory breast cancer

We describe a case of unusual metastases of a gastric carcinoma to the female breast, there likely to be an inflammatory breast cancer. A 46-year-old woman was admitted to our institution with bilateral breast tumors, not typical for a breast cancer as tumor growth was synchronically bilateral within a very short period of only 2 months. The woman underwent a palliative gastrectomy 3 months before for a poorly differentiated adenocarcinoma with signet ring appearance presenting as linitis plastica. At the time of the first operation the mammary glands were not suspicious. Breast biopsies assured metastases of the gastric cancer. In addition to this case report, a short overview of the literature concerning the very few cases of metastases of gastric cancer to the breast is given.