Insights into the transition of ductal carcinoma in situ to invasive ductal carcinoma:morphology,molecular portraits,and the tumor microenvironment

Breast cancer is posing an increasing burden and has become the cancer with the highest incidence among in women in China.The most common histological subtype of breast cancer is invasive ductal carcinoma(IDC)1,2.Ductal carcinoma in situ(DCIS)is a pre-cancerous lesion that may give rise to IDC.DCIS is a highly heterogeneous group of lesions consisting of 5 main types,which differ in clinical presentation,histologic features,biomarker profiles,genetic abnormalities,progression potential,and clinical outcomes.When cancer cells invade through the basal membrane,they acquire the ability to metastasize.This process is usually accompanied by many genetic and epigenetic changes in tumor suppressors and oncogenes.

Molecular and functional imaging in cancer-targeted therapy:current applications and future directions

Targeted anticancer drugs block cancer cell growth by interfering with specific signaling pathways vital to carcinogenesis and tumor growth rather than harming all rapidly dividing cells as in cytotoxic chemotherapy.The Response Evaluation Criteria in Solid Tumor(RECIST)system has been used to assess tumor response to therapy via changes in the size of target lesions as measured by calipers,conventional anatomically based imaging modalities such as computed tomography(CT),and magnetic resonance imaging(MRI),and other imaging methods.However,RECIST is sometimes inaccurate in assessing the efficacy of targeted therapy drugs because of the poor correlation between tumor size and treatment-induced tumor necrosis or shrinkage.This approach might also result in delayed identification of response when the therapy does confer a reduction in tumor size.Innovative molecular imaging techniques have rapidly gained importance in the dawning era of targeted therapy as they can visualize,characterize,and quantify biological processes at the cellular,subcellular,or even molecular level rather than at the anatomical level.This review summarizes different targeted cell signaling pathways,various molecular imaging techniques,and developed probes.Moreover,the application of molecular imaging for evaluating treatment response and related clinical outcome is also systematically outlined.In the future,more attention should be paid to promoting the clinical translation of molecular imaging in evaluating the sensitivity to targeted therapy with biocompatible probes.In particular,multimodal imaging technologies incorporating advanced artificial intelligence should be developed to comprehensively and accurately assess cancer-targeted therapy,in addition to RECIST-based methods.