Cancer is common in our setting and represents a real public health concern in sub-Saharan Africa. It is one of the main causes of morbidity and mortality worldwide: there were approximately 18.1 million new cases and 9.6 million cancer-related deaths in 2018 [1]. Almost one in two deaths worldwide is due to cancer [1].

At the time of the first diagnosis of cancer, the main goal of treatment is to remove the entire tumour, if possible (either as a single treatment or with a combination of surgery, radiotherapy and chemotherapy, and sometimes with newer anti-cancer treatments). Cancer treatment is one of the most complex aspects of medical care. It involves a multidisciplinary medical team (general practitioners, gynaecologists or other specialists, oncologists, radiologists, surgeons and pathologists) and many other health professionals. Oncology imaging is therefore integrated into the patient’s care pathway.

Managing patients with this condition requires a multidisciplinary medical team comprising the radiologist. One of the major challenges of slice imaging in oncology lies in the evaluation of the response to treatment. Standardized treatment response evaluation guidelines are therefore essential in daily clinical practice for therapeutic decision making and treatment monitoring. Thus, the WHO published in 1979 [2] the first standardized guidelines for evaluating response to therapy based on tumor size. These guidelines were revised in 1990 [3] and in 2009 [4] under the name RECIST version 1.1.

However, despite the rapid development of evaluation guidelines for cancer treatment in oncology, there are few studies in sub-Saharan Africa that have used these guidelines in monitoring cancer treatment. We therefore undertook this work with the aim to evaluate the response to cancer treatment using computed tomography.

Our study involved 46 patients treated for cancer, whose mean age was 54.22 years. Our results were similar to those of Kone et al. in 2018 in Mali [5], Darré et al. in 2016 in Togo [6] and Bourio et al. in 2015 in Senegal [7] which reported a mean age of 50, 50.4 and 50 years respectively. This confirms that cancer is more common in adulthood.

A female predominance was found (72%) in our study with a sex ratio of 1:2.5. This is in line with the studies by Kone et al. in 2018 in Mali [5], Goumbri et al. in 2006 in Burkina Faso [8], Ndahindwa et al. in 2004 in Rwanda [9] and Egue et al. in 2016 in Benin [10] which found a female predominance of 83.3%, 54.9%, 54.4% and 56% respectively. This could be explained by the high proportion of gynecomammary cancers in women, and the fact that 51.4% of the general population is made of women according to the fourth general census in Togo [11].

According to literature, radiotherapy is involved in the treatment of around two-thirds of cancers and half of cancers that are curable [12]. The percentage of long-term survivors after radiotherapy alone is 27% while surgery alone contributes 50%, surgery + radiotherapy 14%, chemotherapy 3% and chemotherapy + another treatment 6% [12]. The low rate of patients having received radiotherapy is due to the unavailability of a radiotherapy center in health facilities in Togo. Four patients had received radiotherapy in health facilities of neighboring countries.

The baseline CT scans revealed a predominance of target lesions in the abdomen (28.4%), specifically in the liver, pancreas, stomach, peritoneum and colon at 13.6%, 2.5%, 5.4%, 5.4% and 1.3% respectively. No primary hepatic tumor was detected during our work; all liver lesions were metastatic lesions. This corroborates the data in literature [13] [14] which suggest that the liver is considered as a filter organ in the circulatory system, hence these secondary locations. After treatment, hepatic nodules persisted on both the first and second assessment.

The prevalence of peritoneal nodules was 5.4% and they were found in four patients, two of whom had cervical cancer, one had colon cancer and the last one had an ovarian cancer. According to literature, peritoneal carcinomatosis resulting from implantation of cells, nodules and even cancerous masses on the abdominal peritoneum is a frequent complication of cancers of the digestive and genital systems, but also to a lesser extent of the urinary system [15].

Lymph node involvement was present in 24.4% of cases. According to the natural history of cancers [13], the lymphatic route is the most frequent route of dissemination of carcinomas and the most lymphophilic cancers are carcinomas. This is consistent with the results of our study which indicated carcinoma as the predominant histological type.

One target lesion was in the brain (1.3%); it was a metastatic lesion in a patient with infiltrative ductal carcinoma of the breast. According to literature [16], 5% to 15% of patients with breast cancer develop a secondary brain tumor. This does not occur until later in the course of the metastatic disease and half of such patients would remain asymptomatic. The brain lesion persisted during post-treatment assessment despite radiotherapy, although the treatment administered was the recommended one [17].

Pleurisy (45%), pulmonary micronodules (45%) and alveolar focus (5%) were the main non-target lesions of the thoracic region, representing 55.5% at the baseline assessment. The cancers mainly responsible for these lesions were breast cancer (35%), cervical cancer (25%), endometrial cancer (15%), ovarian cancer (10%), prostate cancer (5%), lung cancer (5%) and stomach cancer (5%). Our results are similar to those of Badri [18] who found as primary cancers at the origin of the various pleuropulmonary metastases: breast cancer (27.6%), gastrointestinal cancers (15.8%), genital cancers (9.2%), sarcomas (7.8%), kidney cancer (5.2%), bladder cancer (5.2%), prostate cancer (3.9%), ENT cancers (3.9%), thyroid cancers (3.9%), skin cancer (2.6%) and primary cancer of undetermined origin (14.4%). There was a significant disappearance of these lesions during the second assessment.

Bone lesions were second to thoracic lesions (27.7%). According to Debiais [19] and Bouabid [20], it is the third site of cancer metastases after the liver and the lung. Bone metastases are secondary to breast or prostate cancer in 84% of cases, to thyroid cancer in 50% of cases, to lung cancer in 44% of cases and to kidney cancer in 37% of cases [21]. In our study, breast cancer was the main source of these lesions (50%). These lesions persisted at the post-treatment evaluation.

Ascites was the only non-target lesion found in the abdominal area (16.8%). Ovarian cancer was the main source of these lesions (50%) due to the peritoneal location of the ovary. This corroborates the data in literature showing that neoplasms most often associated with malignant ascites are adenocarcinomas of the ovary, breast, colon, stomach and pancreas [22].

The new lesions primarily involved the abdominal region at the first assessment (50%), and the thorax at the second assessment (50%). This is consistent with the natural history of cancer [23] which labels the lungs as filter organs in blood circulation, hence a predominant site for secondary tumors.

In conclusion, cancers are present in Togo among the population at all ages. Breast and cervical cancers remain the most common. Computed tomography evaluation using the RECIST version 1.1 guidelines makes it possible to follow the evolution of cancerous lesions as well as their extensions, thus playing a crucial role in their management. Most patients had stable disease. Breast cancer was the one with the most significant regression disease.

The authors thank the authorities and the health professionals of campus and Sylvanus Olympio tcheatching Hospitals and surrounding health facilities for their help in data collection and all the participants.

The authors declare no conflicts of interest regarding the publication of this paper.

Amadou, A., Gbande, P., Adani-Ifè, A., Dagbe, M., Youaleu, I., Sonhaye, L., Agoda-Koussema, L.K. and Adjenou, K. (2021) Computed Tomography Evaluation of Tumor Response in Oncology in Togo. Journal of Cancer Therapy, 12, 695-707. https://doi.org/10.4236/jct.2021.1212061