According to GLOBOCAN (Global Cancer Observatory) data in 2022, colorectal cancer in Indonesia is ranked 4th in new cases with the number of deaths due to cancer ranked 5th. Treatment for colorectal cancer has been very advanced, but the recurrence rate is still high even though patients with the same stage receive the same treatment. The process of colorectal cancer occurs through several stages and is influenced by genetic and epigenetic factors. Not all colorectal cancer patients respond positively to the new cancer drugs given to them, including immunotherapy. Determining the choice of drugs requires several additional parameters in addition to the examinations needed to determine the type of cancer.
One of the genetic factors that influence the occurrence of cancer and was studied in this study is the presence or absence of a protein that functions to repair DNA abnormalities (mismatch repair/MMR) that occurs. The results found that age was significantly related to this MMR status, those over 50 years of age had more of this protein than those under 50 years of age and those under 50 years of age were found to lose more of this protein than those over 50 years. No significant relationship was found between MMR status and survival.
Tumor budding is cancer cells found outside the center of the cancer, which is the beginning of the spread of cancer cells to other places. This study found that there is a significant relationship between tumor budding and the depth of cancer cells infiltrating (invading) into the intestinal wall, the spread of lymph nodes and the occurrence of metastasis. Colorectal cancer that has a high number of tumor budding has a higher risk of cancer invading deeper, there is spread of lymph nodes and metastasis. No significant relationship was found between tumor budding and survival, but the more the number of tumor budding, the greater the risk of death.
The number of immune cells that function to destroy cancer cells, including T cells, produced by the patient’s body will greatly affect the response to treatment and ultimately affect the patient’s survival. This study determines the cut-off value to be able to create a category of low and high T cell counts because the number of immune cells in Indonesians is different from other ethnic groups. If the number of T cells in a case is less than the cut-off value, it is categorized as low and if the number of T cells is higher than the cut-off value, it is categorized as high.
From the statistical analysis, it was found that there was no relationship between the number of immune cells with age, gender, differentiation, location, depth of cancer cells infiltrating the intestinal wall, lymph node spread, tumor budding, genetic status and metastasis in colorectal cancer. Analysis of survival found that T cells, especially the CDS type, can be used as a factor that can predict patient survival. Colorectal cancer with a low number of CD8 T cells has a higher risk of death compared to those with a high number. Researchers recommend that these three biomarkers be routinely checked as part of a more personalized cancer treatment for colorectal cancer in order to avoid recurrence and reduce the use of inappropriate drugs.