Frequency of Morphologic Prognostic Factors in Surgically Treated Colorectal Cancer

Abstract

Summary Introduction. Colorectal cancer is one of the most frequent malignant tumours worldwide. In Latvia, the incidence and mortality from colorectal cancer has increased over the past five years. Surgery is the mainstay of colorectal cancer treatment. However, the prognosis of an individual patient after the operation depends on many factors. Here, we report the prognostically important morphologic factors in potentially radically operated colorectal cancer patients in order to create the “morphologic prognostic portrait” - the basic morphologic characteristics of colorectal cancer in Latvian patients. Such data could be helpful in prognostic estimates. Aim of the study was to describe the local tumour spread by pT, to evaluate the occurrence of certain morphologic prognostic factors and to assess lymph node involvement in potentially radically operated colorectal cancer patients. Material and methods. In a retrospective study, 173 consecutive patients who underwent a potentially radical operation in a single university hospital within the year 2012 were identified by archive search. The pathology reports that have been created by protocol approach and diagnostic microscopy slides were reanalysed. Tumour morphology and pTN parameters were assessed according to the World Health Organization and the American Joint Committee on Cancer classifications. Results. The study included 98 women (56.6%) and 75 men (43.4%). The mean age of patients was 68.5 years [95% confidence interval: 66.9 – 70.1]. Only 4.6% [2.4 – 8.9] of patients were younger than 50 years. The most frequent histological tumour types were colorectal adenocarcinoma in 86.7% [80.8 – 90.9] patients and mucinous carcinoma in 9.2% [5.7 – 14.5] of patients. Evaluating the pT parameter, pT3 was found in 43.2% [36.1 – 50.6] and pT4 in 39.8% [32.8 – 47.2] of cases. Lymphatic invasion was found in 35.1% [25.3 – 46.2] of pT3 and 75.4% [64.0 – 84.0] of pT4 cases; p < 0.001. Perineural cancer invasion in pT3 and pT4 tumours was found in 29.9% [20.8 – 40.9] and 69.6% [57.9 – 79.2], respectively; p < 0.001. Conclusions. Colorectal cancer affects both genders with equal frequency. The tumour is mostly diagnosed after the age of 60 years. Adenocarcinoma is the predominant colorectal cancer type in radically operated patients. Perineural and lymphatic invasion in pT4 tumours is statistically significantly more frequent than in less advanced tumours and thus may be pathogenetically linked to wide local tumour spread.