Incidence, Risk Factors And Management Of Neutropenia Among Cancer Patients With Solid Tumors Receiving Chemotherapy At Kenyatta National Hospital Cancer Treatment Centre

Abstract

Background: Cancer accounts for approximately 7-10% of deaths in Kenya. It is managed through surgery, chemotherapy, radiotherapy and hormonal therapy. Each of these interventions present benefits and risks. Chemotherapeutics are known to cause a number of adverse effects. Chief among them is neutropenia. Neutropenia is considered the most serious hematologic toxicity. It is linked to serious infections, chemotherapy dose adjustments and delays that may compromise therapeutic outcomes. Few studies have been carried out to determine incidence of chemotherapy induced neutropenia (CIN) in Kenya. Objectives: The main objective of the study was to determine the incidence and risk factors, and identify the interventional strategies and gaps in management of chemotherapy-induced neutropenia. Methods: This was a retrospective observational cohort study. Participants were recruited from among adult cancer patients who received chemotherapy at the cancer treatment centre at KNH from January to March 2016. Data were abstracted from participants’ files on their bio-data, type of cancer, co-morbidities, diagnosis for neutropenia and the strategy used to manage chemotherapy-induced neutropenia. Selected files were reviewed for a period of one year. Abstracted data were recorded into a pre-tested case record form. Descriptive analysis was carried out using STATA version 13 and findings presented in form of proportions, ratios, pie-charts, histograms and tables. Logistic regression analysis was carried out using STATA version 13 to identify the combinations of risk factors most likely to have caused neutropenia. Results. Forty seven (27.17%) of the 173 participants developed neutropenia during the period under review. The most important risk factor was administration of cyclophosphamide. 45.7% of all participants treated using cyclophosphamide developed neutropenia. Neutropenic effects were found to be age dependent. Internally standardized risk ratio for participants aged 50 years and above was 4.71(2.27-9.77). In participants aged below 50 years, the neutropenic effect was minimal with a risk ratio of 0.92(0.41-2.04). Participants aged 50 years and above were almost five times at risk of developing neutropenia compared to participants aged 50 years and below. xiv Doxorubicin had a protective effect which confounded the association between cyclophosphamide and neutropenia. The odds ratio of developing neutropenia after administration of cyclophosphamide reduced from 9.23(2.6-32.80) to 2.02(0.16-25.73) after adjusting for the protective effects of doxorubicin. Although breast cancer had the highest incidence of neutropenia, this was attributed to its treatment with cyclophosphamide. The main intervention for chemotherapy-induced neutropenia was administration of a granulocyte colony stimulating factor for 29(61.7%) of participants. Conclusions and recommendations. The number of new cases of neutropenia was high at 27.2% of the participants. The risk of neutropenia varied with age. Patients aged 50 years and above may require close monitoring for neutropenic effects especially those treated using risky regimens. Cyclophosphamide was found to present a significant risk of developing neutropenia. A protocol for determining risk profiles of patients on cyclophosphamide should be developed. Such a protocol should include strategies for managing neutropenia if, and once it develops. Majority of participants developing neutropenia were managed using a granulocyte colony stimulating factor (GCSF). The rest were treated with antibiotics or had their chemotherapy deferred.