The triple-negative breast cancer (tnbc) is an aggressive subtype linked to a poor outcome of established breast cancer therapy. Increasing evidence points to the role of the tumor’s extracellular matrix (ECM) as a determinant of its aggressiveness as well as the effectiveness of chemical therapeutics. Three-dimensional imaging techniques can be used to unravel ECM architecture. Label-free contrast mechanisms such as second harmonic generation (SHG) avoid falsification and artifacts introduced by the labeling process. Here, we present the complementary use of two-photon excitation microscopy (TPEF) and Scanning Laser Optical Tomography (SLOT) for the investigation and quantification of tumor ECM. Both methods were used to capture fluorescence from antibody-labeled samples as well as the SHG signal from collagen strands in the ECM. SLOT generally allows for the investigation of larger samples of several mm up to a few cm in size. This work shows the capabiliti es of the tomographic setup compared to established TPEF, and demonstrates their combined use to maximize the information content of the acquired data. The obtained images served as a basis for ECM quantification. 3D-analysis allowed for determination of length, straightness and orientation of the collagen fibers based on fluorescence imaging as well as SHG imaging. The resulting coordinates might be used for synthetic reconstruction of a patient-specific tumor matrix, serving as a scaffold for pre-clinical therapeutic testing. Collagen imaging and quantification as presented here can therefore be employed for both basic and clinical research, paving the way for patient-specific cancer therapy.