Cancers early stage detection

Accurate biopsies are vital to prostate cancer detection and, hence, treatment. Early stage detection requires accurate imaging systems and precise needle insertion techniques to probe small potential tumors. Currently, ultrasound imaging is used to manually insert a biopsy needle to the prostate. Unfortunately, the biopsy needle often misses the tumor because ultrasound images are too low resolution to see small, early stage, tumors. Tumors smaller than 5 mm are not detected by ultrasound imaging [ 11 ]. Only about 20 % of tumors between 5 and 10 mm are detected by ultrasound. Even large tumors, of the order of 20-25 mm, are only detected 79 % of the time. 

Prostate-specific antigen (PSA) is a useful marker for detecting prostate cancer at early stages, predicting outcome for localized disease, defining disease-free status, and monitoring response to... 

Signs and symptoms of colorectal cancer can be extremely varied, subtle, and nonspecific. Patients with early-stage colorectal cancer are often asymptomatic, and lesions are usually detected by screening procedures. 

Currently, anastrozole and letrozole are efficacious in early-stage, locally advanced, and mefasfafic disease and fhus they present with the most complete data set for the different stages of breast cancer. Although it seems rather unlikely that one will be able to detect differences with respect to clinical effects at the tumour level, the indirect comparison of different AIs suggests a stronger evidence for the use of exemestane compared with other AIs for breast cancer therapy [90]. 

Cancer is a particularly important disease to treat early, before the disease invades too much tissue. Quantum dots may offer one important method of detecting the disease in its early stages. Cancerous cells often make certain proteins or other molecules that are attached to the cell s membrane and help the cell to grow and divide. These proteins are not found in healthy cells or are much rarer than in cancerous ones and, therefore, can serve as miniature markers for the diseased cells. These markers would make cancer cells easy to detect, but physicians do not usually have an effective tool with which to see them. 

Overall, it is estimated that more than one in three people will develop some form of cancer during their lifetime [1], Traditional methods of cancer diagnosis involve surveillance of at-risk populations or investigation of suspicious symptoms. Unfortunately, often by the time a patient is symptomatic it is too late to facilitate a full cure. However, most cancers need not be killers if they can be exposed to the wide range of improving treatments at an early stage. The primary requirement for the successful treatment of any malignancy is early accurate detection. 

Because 2D-PAGE and MS patterns can be used to differentiate between healthy and cancer patients, the proteins in these spectra contain tumor markers. If they could be isolated and identified, they would be useful for innumerable purposes, most notably for early detection. If a tumor marker can warn of the presence of disease at an early stage, before the cancer can be visualized using imaging studies, this would increase the chances of treating at a curative stage. 

Yu LR, Zhou M, Conrads TP, Veenstra TD. Diagnostic proteomics Serum proteomic patterns for the detection of early stage cancers. Dis Marker 2003 19(4-5) 209-218. 

Another method to increase the number of metals associated with each macromolecule is to attach them, in a chelated form, to a carrier molecule with many sites of attachment. An example of this can be found in the work of Meade [29], His group has synthesized a fi-cyclodcxtrin from which seven Gd-DOTA complexes were attached using highly efficient click chemistry. The contrast agent was observed to accumulate in primary cancers but then localize in secondary metastases over the subsequent 48 hours. This is a particularly valuable property as one of the main problems with cancer treatment is the inability to detect these small secondary tumours in their early stages. 

Other publications also confirm the potentially significant role of nucleosides in the diagnosis of urogenital tract cancer [24, 25]. The use of sensitive determination techniques (e.g., LC-MS/MS) for analysis of metabolites from biological samples of healthy subjects and cancer patients allows detection of significant differences between even small concentrations of metabolites (as can occur in the case of nucleosides) and selection of potential cancer markers that could be used to diagnose the disease at an early stage of development. 

The clinical use of PAP has been replaced by PSA. PAP is not as sensitive as PSA for screening or for detection of early cancer. The clinical use of PAP is restricted to confirmation of metastatic prostate cancer and staging of prostate cancer. It is less likely to be elevated in BPH than is PSA. Currently the method of choice for PAP is the measurement of its enzymatic activity. 

---