MCT1 in Invasive Ductal Carcinoma: Monocarboxylate Metabolism and Aggressive Breast Cancer.

Introduction: Monocarboxylate transporter 1 (MCT1) is an importer of monocarboxylates such as lactate and pyruvate and a marker of mitochondrial metabolism. MCT1 is highly expressed in a subgroup of cancer cells to allow for catabolite uptake from the tumor microenvironment to support mitochondrial metabolism. We studied the protein expression of MCT1 in a broad group of breast invasive ductal carcinoma specimens to determine its association with breast cancer subtypes and outcomes. Methods: MCT1 expression was evaluated by immunohistochemistry on tissue micro-arrays (TMA) obtained through our tumor bank. Two hundred and fifty-seven cases were analyzed: 180 cases were estrogen receptor and/or progesterone receptor positive (ER+ and/or PR+), 62 cases were human epidermal growth factor receptor 2 positive (HER2+), and 56 cases were triple negative breast cancers (TNBC). MCT1 expression was quantified by digital pathology with Aperio software. The intensity of the staining was measured on a continuous scale (0-black to 255-bright white) using a co-localization algorithm. Statistical analysis was performed using a linear mixed model. Results: High MCT1 expression was more commonly found in TNBC compared to ER+ and/or PR+ and compared to HER-2+ (p \u3c 0.001). Tumors with an in-situ component were less likely to stain strongly for MCT1 (p \u3c 0.05). High nuclear grade was associated with higher MCT1 staining (p \u3c 0.01). Higher T stage tumors were noted to have a higher expression of MCT1 (p \u3c 0.05). High MCT1 staining in cancer cells was associated with shorter progression free survival, increased risk of recurrence, and larger size independent of TNBC status (p \u3c 0.05). Conclusion: MCT1 expression, which is a marker of high catabolite uptake and mitochondrial metabolism, is associated with recurrence in breast invasive ductal carcinoma. MCT1 expression as quantified with digital image analysis may be useful as a prognostic biomarker and to design clinical trials using MCT1 inhibitors

Pyoderma Gangrenosum Associated with Acute Myelogenous Leukemia

A 20-year-old man presented with a non-healing ulcer on the dorsum of the left foot that initially appeared after the patient fell and hit his left foot on the edge of a door. An ulcer had formed and grown in size over the past several weeks after repeated physical insults and despite home wound care, as seen in Figure 1. Additionally, the patient had a non-healing ulcer inferior to his left knee. He had a notable past medical history of acute myelogenous leukemia (AML) in remission after a haploidentical stem cell transplant, uncontrolled diabetes type 1, and graft-versus-host disease of the skin. Both wounds showed no signs of osteomyelitis or cellulitis on MRI