Morphological features and criteria of prognosis for stromal component of colorectal cancer ІІА-ІІІВ stages

Abstract

Colorectal cancer (CRC) is the second leading cause of mortality among cancers after tumors of the respiratory system. One of the most significant prognostic criteria of CRC are the features of stromal component, which are not implemented in clinical practice. The aim was to study the main morphological features of the stroma of CRC T3N0-2M0 and to search for prognostic criteria of their recurrence and death. Group I included primary CRC without recurrences. Group II – primary CRC with recurrences; IIA – with recurrences that did not lead to death; ІІВ – with recurrences and fatal outcome from generalization of tumor process during 5 years from lethal outcome from the moment when the tumor was removed. The microslides of CRC were made by using the standard methods with G + E staining; immunohistochemical (IHC) reaction was performed by using monoclonal antibodies to smooth muscle actin alpha and vimentin. CRC with a stromal-parenchymal ratio (SPR)>50% were in 43.3% (26/60) of cases. SPR>50% is a prognostic criterion for recurrence (p<0.05), shorter disease free survival (p<0.001) and metastasis to regional lymph nodes (p<0.001). Immature stroma type of CRC IIA-IIIB stages is associated with the presence of tumor budding (p<0.001), G3 differentiation (p<0.01), shorter disease-free survival (p<0.001), metastatic activity (p<0.05); among recurrent CRC, the immature type of stroma is associated with the death of patients (p<0.05). A diffuse presence of tumor-activated fibroblasts is one of the criteria for immature CRC stroma (p<0.003), however, as an independent prognostic feature, it has limited prognostic value. SPR>50% and immature type of stroma are prognostic features for recurrence, metastasis and term of recurrence for CRC pT3N0-2M0; the presence of an immature type of stroma was associated with patient death.