Colorectal Cancer Diagnosis and Therapeutic Updates

A diagnosis is an important tool in the detection and combat of colorectal cancer. Early-diagnosed cancer can be cured easily. There are many invasive as well as non-invasive methods of diagnosis for colorectal cancer. Non-invasive methods usually involve the use of various biomarkers for diagnostic purposes. Recently, enzymes from lysosomes that take part in metastases have been discovered to have importance as a diagnostic tool. 

Colorectal carcinoma is the fourth most commonly diagnosed malignancy. As it is hidden in many cases and as the onset is undetectable, it may prove to be fatal. Hence, early screening colorectal cancer is a way to prevent this disease. Screening depends upon various factors, such as familial history, history of the disease, or any condition which could lead to colorectal carcinoma. Various tests, such as fecal occult blood test, sigmoidoscopy, and CT scan, are available for screening. The screening method to be used depends upon various contributing factors. Screening can be invasive or can be non-invasive using many markers. 

 Histopathology involves the study of tissue samples using a microscope to understand the normal and abnormal contents of a given sample. Normal histology of colorectal areas, such as mucosa and muscular, is greatly altered during the development of cancer. Colorectal cancer can be divided into various grades during the histopathological examination of tissues, which shows the extent of invasion of tumour into the colon. This examination can also be used to understand the type of carcinoma in the colon. Many factors affect this histopathological study and many drawbacks can occur in grading systems that need to be improved.

Chemotherapy is one of the established first-line options for the treatment of colorectal cancer. Chemotherapy contains various molecules acting against multiple factors, contributing to the growth of cancer cells. Chemotherapeutic regimens can vary based on the stages of cancer and the components as well as the strength of medications. The recent addition of agents such as antibodies against various molecular targets involved, such as receptors and components of signaling pathways, resulted in even more precise therapy. 

Surgery is one of the primary methods for the removal of colorectal cancers. Various surgeries are performed based on the location of cancer and its spread. Due to many shortcomings of extensively invasive procedures, laparoscopy was invented to visualize cancer perfectly and later remove that tumor. However, some technical difficulties were observed, and the physiological complexity of the tumour site caused this method to fail. Later, the FDA announced the approval of a surgical system operated by a team of specialists. This system has more enhanced precision compared to conventional treatments, showing increased efficacy. 

Colorectal cancer (CRC) is a disease that is initiated by the interrelation of genetic and environmental factors. Colorectal cancer progresses through the accumulation of genetic and epigenetic changes. This review discusses, in detail, the role of lncRNAs in colorectal cancer, focusing on various signaling pathways involved in colorectal cancer pathogenesis, viz., Wnt/-catenin signaling pathway, epidermal growth factor receptor (EGFR)/insulin-like growth factor type I receptor (IGF-IR) signaling pathway (KRAS and phosphatidylinositol-3-kinase (PI3K) pathways), transforming growth factor-beta (TGF-) signaling pathway, p53 signaling pathway, and the epithelial-mesenchymal transition (EMT) program. 

Signaling pathways are important tools for regulating cellular life cycles such as growth and replication. Any external influences may cause a disturbance in signaling, causing an uncontrolled division of cells causing cancer. Many receptors such as EGFR are active in signaling for cancer, which can be targeted to show potent anticancer activity.

Radiotherapy has become an integral part of the treatment of colorectal cancer. Radiotherapy is used as adjuvant therapy in combination with chemotherapy or surgery. In the article, various types of radiotherapy are explained and also the factors involved in the selection of radiotherapy. There have been many clinical trials for investigating the efficacy of various novel radiotherapies, which may show some promising results. Radiotherapy can be adjuvant or neoadjuvant in the combination of first-line therapy to increase the overall effectiveness of the treatment.

The incidence of colorectal cancer is very high, and emphasizing the mortality rate of CRC, good screening and surveillance methods are essential for the effective treatment of cancer. Early detection of the CRC is the key for its treatment. If not detected early, it can cause serious symptoms like bleeding and difficulty in bowel movement, which are considered serious symptoms. Different screening procedures are available for the screening and detection of cancer, but the most commonly used technique is colonoscopy, and another less common technique is flexible sigmoidoscopy. People who have a screening colonoscopy have a cancer mortality rate of 68 percent to 88 percent lower. Flexible sigmoidoscopy, although used in many cases has certain limitations, and therefore, colonoscopy outplays it.

Colorectal cancer (CRC) is the common form of cancer occurring worldwide, having a high occurrence rate and also high mortality (death) rate. Chemotherapy and conventional approaches to treat CRCs are outdated and newer strategies are required to combat colorectal cancer. Neoadjuvant therapies have also shown some promise but have some major side effects, like building up intrinsic resistance and systemic toxicity problems associated with such therapies. Cancer nanomedicine, a rapidly developing interdisciplinary research field, is one of the new strategies being developed to address these issues. The use of nanoparticles and nanotechnology in cancer medicine has exploded in popularity over the last few decades. This is due to nanoparticles' suitable physical and chemical properties for in vivo applications. Cancer nanomedicine has been extensively studied in preclinical and clinical settings for targeted drug delivery and imaging. Nanomedicine, along with the theranostic approach, has been proposed as a novel way to improve CRC diagnosis and treatment.

Management of colorectal cancer is a very important part of treatment as improper procedures may cause certain complications. Many decisions regarding the treatment depend on the condition of the tumour and the patient, and also the focus is on the treatment to be perform without complications. Management is done by first preparing the patient with different procedures, like stomal therapy, bowel preparation, or nutritional intervention. Then, the tumour is further evaluated, and accordingly, the treatment option is selected. Possible treatment options could be electrocoagulation, touch radiotherapy, local excision with or without neoadjuvant/adjuvant therapy; they all are local treatment methods for rectal cancer and endoscopic treatment. The results may vary with the selection of the procedure and the prognosis.