Epidemiological profile of cancer at the laboratory of anatomy and pathological cytology of mungbere in the Democratic Republic of Congo

INTRODUCTION

Cancer is the second leading cause of death worldwide, causing about 10 million deaths per year, 70 % of which occur in low- and middle-income countries. In the DRC, the absence of a national cancer registry is a handicap to the definition of a strategy to combat this disease. The purpose of this study is to establish an epidemiological profile of cancer in this laboratory in order to overcome this deficit in this part of the country.

METHODOLOGY

We conducted a descriptive study of 1636 histopathological analysis reports from 2015 to 2021 at the Anatomy and Pathological Cytology Laboratory of Anualite Hospital in Mungbere.

RESULTS

A total of 502 cases of cancer have been identified; female accounted for 51.4 % of cases; all age groups are affected; The most common cancers in both sexes are Kaposi's sarcoma (17.9 %), breast cancer (15.3 %), lymphoma (13.7 %), cervical cancer (9.6 %) and squamous cell carcinoma of the skin (9 %). In women, breast cancer (27.1 %), cervical cancer (18.6 %), Kaposi's sarcoma (10.1 %), lymphoma (7.4 %) and squamous cell carcinoma of the skin (5.8 %) and in men Kaposi's sarcoma (26.2 %), lymphoma (20.5 %), liver cancer (13.1 %)) and squamous cell carcinoma of the skin (12.3 %).

CONCLUSION

Cancer affects all age groups with a slight female predominance. The most common in both sexes are Kaposi's sarcoma, breast cancer, lymphoma, cervical cancer and squamous cell carcinoma of the skin. For an effective fight against cancer, the creation of a national cancer registry is an emergency in our country.

Titanium for removable dentures. I. Laboratory procedures

To test the hypothesis that titanium (Ti) removable partial dentures (RPDs) would function for a period of at least 2 years without failure, 10 patients were selected to receive dentures made from Ti and Co-Cr. The Ti RPDs were constructed identically to conventional cobalt-chromium (Co-Cr) dentures. Five complete Ti dentures were also included and the laboratory procedures involved for making both complete and partial dentures were evaluated. The detection of internal defects by radiography made the screening of Ti castings possible and led to a rejection of specimens showing porosities of more than 0.5 mm in flexible members. Co-Cr frames on the other hand cannot be screened in this way. The success rate in the casting of Ti was 60% for both partial and complete dentures, but as casting technology has since improved, the rate is expected to be higher, particularly where complete denture palates have optimum thickness. The success rate in the casting of Co-Cr RPDs was 100% without radiographic screening. The weight difference between Ti and Co-Cr RPDs was in the range of 1.3 to 3.9 g at issue and is generally higher as the volume of denture frames increases. A large difference would be of clinical significance in maxillary complete dentures. The low density of Ti allows for the adoption of a useful pre-clinical quality-control process using commonly available dental X-ray units.

The effect of investment type on the fit of cast titanium crowns

In order to determine the best laboratory procedure for titanium crown casting, a set of thermal expansion measurements and casting experiments were carried out using a casting machine (argon arc, pressure difference type) and three different investments, two conventional SiO2 based investments and a new Al2O3/MgO based investment. The thermal expansion measurements involved a cycle of heating and cooling. The relatively low mould temperatures recommended (200 degrees C) or chosen (350 degrees C) for the conventional investments provided zero or negative mould expansion for the compensation of metal shrinkage. Crowns made from these investments exhibited heavy reaction with the mould, and the common cleaning method of sand blasting appeared to be essential. This cleaning process, however, was not adequate for the assessment of casting accuracy as the short sand blasting time (15 s) rapidly altered the fit of the crowns. The metal reacted little with the new investment and the best compensation (0.15 mm discrepancy) for the metal shrinkage, as assessed 'as cast', was achieved when the investment was heated to 950 degrees C and then cooled to the recommended mould temperature (600 degrees C).