No abstract

We used monoclonal antibodies to identify occult micrometastases in the bone marrow of 49 patients with operable (stage I and II) breast carcinoma. Follow-up (mean, 29 months; median, 30 months) revealed that 12 patients recurred. The presence of bone marrow micrometastases (BMM) was significantly associated with early recurrence (P less than .04). The estimated 2-year recurrence rate for patients with no BMM detected (BMM-) was 3%; in patients with BMM, the 2-year recurrence rate was 33%. When BMM and axillary lymph node (LN) status were combined, groups of patients at low risk (LN-, BMM-; 2-year recurrence rate, 0%) and high risk (LN+, BMM+; 2-year recurrence rate, 42%) for early recurrence were identified. Bone marrow tumor burden was related to early recurrence. Among patients with BMM, those who did not recur had on average fewer extrinsic cells in their marrow than those who recurred (15 v 43 cells, respectively). Multivariate analysis comparing BMM, LN+ versus LN-, and tumor size (less than or equal to 2 cm v greater than 2 cm) revealed no factor independently associated with early recurrence. Peripheral tumor burden of BMM (0 or less than 10 extrinsic cells v greater than or equal to 10 extrinsic cells) was the only independent predictor of early recurrence (P less than .003). In conjunction with conventional prognostic factors, particularly axillary LN status, evaluation for BMM might be used to stratify patients for adjuvant treatment programs. Because this pilot study involved few patients with short-term follow-up, the results should be interpreted with caution. The examination of bone marrow for micrometastases remains an experimental procedure; the clinical usefulness of the test will be established through larger studies with long-term follow-up.

The most important factor affecting the outcome of patients with invasive cancers is whether the tumor has spread, either regionally (to regional lymph nodes) or systemically. However, a proportion of patients with no evidence of systemic dissemination will develop recurrent disease after primary 'curative' therapy. Clearly, these patients had occult systemic spread of disease that was undetectable by methods routinely employed (careful pathological, clinical, biochemical and radiological evaluation). In addition, the success of adjuvant therapy is assumed to stem from its ability to eradicate occult metastases before they become clinically evident [1]. Therefore, methods for the detection of occult metastases in patients with the earliest stage of cancer, i.e., prior to detection of metastases by any other clinical or pathological analysis, have received a great deal of attention.

No abstract

Consequences of the obesity epidemic on cancer morbidity and mortality are not fully appreciated. Obesity is a risk factor for many cancers, but the mechanisms by which it contributes to cancer development and patient outcome have yet to be fully elucidated. Here, we examined the effects of coculturing human-derived adipocytes with established and primary breast cancer cells on tumorigenic potential. We found that the interaction between adipocytes and cancer cells increased the secretion of proinflammatory cytokines. Prolonged culture of cancer cells with adipocytes or cytokines increased the proportion of mammosphere-forming cells and of cells expressing stem-like markers in vitro. Furthermore, contact with immature adipocytes increased the abundance of cancer cells with tumor-forming and metastatic potential in vivo. Mechanistic investigations demonstrated that cancer cells cultured with immature adipocytes or cytokines activated Src, thus promoting Sox2, c-Myc, and Nanog upregulation. Moreover, Sox2-dependent induction of miR-302b further stimulated cMYC and SOX2 expression and potentiated the cytokine-induced cancer stem cell-like properties. Finally, we found that Src inhibitors decreased cytokine production after coculture, indicating that Src is not only activated by adipocyte or cytokine exposures, but is also required to sustain cytokine induction. These data support a model in which cancer cell invasion into local fat would establish feed-forward loops to activate Src, maintain proinflammatory cytokine production, and increase tumor-initiating cell abundance and metastatic progression. Collectively, our findings reveal new insights underlying increased breast cancer mortality in obese individuals and provide a novel preclinical rationale to test the efficacy of Src inhibitors for breast cancer treatment. Citation Format: Picon-Ruiz M, Pan C, Drewes-Elger K, Jang K, Besser A, Zaho D, Morata-Tarifa C, Kim M, Ince TA, Azzam D, Wander S, Cote RJ, Guy HA, El-Ashry D, Torne-Poyatos P, Marchal JA, Slingerland JM. Interactions between adipocytes and breast cancer cells stimulate cytokine production and drive Src/SOX2/miR-302b mediated malignant progression [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-05-01.