ABSTRACT
BACKGROUND: Colorectal carcinoma (CRC) is a major cause of morbidity and mortality worldwide. Microsatellite instability pathway is important in the pathogenesis of CRC. Immunohistochemistry expression of mismatch repair (MMR) proteins serves as surrogate marker for MMR gene mutation. AIMS: This study aimed to determine MSI status of a cohort of CRC cases using immunohistochemistry. MATERIALS AND METHOD: Surgical pathology blocks of resected colonic carcinoma (CC) between 2011 and 2015 were extracted from our departmental archives and The Specialist Laboratories in Lagos. Immunohistochemical expression profile of 4 MMR proteins was assessed in the representative blocks and this was correlated with the demographic and pathological characteristics. RESULTS: There were 19 males and 16 females with CC, mean age of 51.6 years, and 40% of them were below 50 years of age. Twenty (57.1%) out of the 35 CC cases seen were mismatch repair proficient (pMMR) while the remaining 15 (42.9%) were mismatch repair deficient (dMMR). Seven dMMR cases were seen equally on the right and left colonic tumors respectively. Five (71.4%) out of the 7 mucinous tumors in this study were dMMR, right sided with 3 of them in patients who were below 50 years of age. CONCLUSION: The frequency of mismatch repair deficiency in CC among Nigerians is high, and presence of right-sided mucinous colon cancer in patients below 50 years is highly suggestive of dMMR status. Mutation studies of larger patient samples to determine the percentage with germline mutation will further our knowledge, and influence therapeutic options for CC.
Subject(s)
Colorectal Neoplasms , DNA Mismatch Repair , Colorectal Neoplasms/genetics , DNA Mismatch Repair/genetics , Female , Humans , Immunohistochemistry , Male , Microsatellite Instability , Middle Aged , NigeriaABSTRACT
BACKGROUND: Gastrointestinal malignancies have continued to record higher incidence and therefore pose significant public health burden in terms of morbidity and mortality. AIM: To evaluate the sociodemographic, histologic and clinical distribution of patients with gastrointestinal malignancies diagnosed between July 2009 and March 2016. SETTING: Lagos University Teaching Hospital, Idi-Araba, south-west Nigeria. METHODOLOGY: Using a retrospective study design, all the patients with histologic diagnosis of gastrointestinal malignancies were recruited and their bio-data, clinical, histologic and treatment data were extracted from their hospital records. RESULTS: Of the 106 cases of gastrointestinal malignancies in this study, the age range was 30-82 years with a mean of 55.9±13 years and a peak age bracket of 50-59 years; the male/female ratio was 1.2:1. The most common sites were colorectum (79.3%), stomach (7.6%), anus (6.6%), liver (4.7%), and pancreas (0.9%). Adenocarcinoma was the most common histologic subtype (89.62%), followed by squamous cell carcinoma (2.83%) and gastrointestinal stromal tumors (1.89%). The most common complaints were abdominal pain (54.7%), constipation (38.7%), palpable abdominal swelling/masses (35.9%), bleeding (33.0%), and weight loss (17.0%). The tumors were treated with chemotherapy, surgery, and radiotherapy, either singly or in combination, in 97.2%, 83.0%, and 30.2% respectively. CONCLUSION: In this study, colorectal cancers are still the most prevalent type of gastrointestinal malignancies with a male preponderance, and individuals between 40-59 years are at greater risk. The significant involvement of individuals who constitute the bulk of the workforce and are the most productive labor in the country points at the need to develop strategies aimed at reducing the incidence of gastrointestinal malignancies.