**5.5. Other cancers**

Besides skin, oral, gastric and breast cancers, Raman spectroscopy techniques are also applied to diagnose other types of neoplasia (**Table 1**), mainly *in vitro*. For instance, in 2011, there was a study that used modulated Raman spectroscopy to detect the presence of human urothelial cells and bladder cancer cells after cell lines were incubated with urine [41]. The results achieved high sensitivity and specificity and, in the future, this approach may be applied in routine urine exams to detect bladder cancer or to monitor patients under treatment for bladder cancer.

Blood samples are widely used in the context of diagnosis. In the case of colorectal cancer, Lin et al. used gold nanoparticle-based SERS in blood serum samples of 83 patients to differentiate Raman spectra of healthy and disease samples [42]. This approach allowed to achieve sensitivity and specificity of 97.4 and 100%, respectively. Besides, the authors detected spectral differences between normal and cancer samples, mainly an increase in the relative amount of nucleic acids and a decrease in the amount of proteins in colorectal cancer patients, compared to control healthy subjects [42]. Serum blood samples can also be used to monitor the efficacy of treatments. In the specific case of leukemia, Gonzalez et al. used standard Raman spectroscopy and multivariate analysis to distinguish normal samples from leukemia samples with 100% of both sensitivity and specificity [43]. The authors detect some molecular changes between both groups of samples, mainly in the regions of lipids, phospholipids and β-carotene. Therefore, this Raman-PCA technique can be easily applied as a noninvasive tool to diagnosis and progression evaluation of leukemia.

In the last decade, there was an increase in the use of Raman spectroscopy in the field of cancer diagnostic and monitoring. As it was possible to see in this section, the improvement in the algorithms to process Raman signals as well as the development of new SERS techniques and fiber optic probes allowed to produce results with high sensitivity and specificity and to apply Raman-based approaches in *in vivo*, *ex vivo* and *in vitro* clinical diagnosis of several cancer types in different biological samples.
