As defined by the World Health Organization (WHO 2019), complementary medicine (CM) is a collection of healthcare practices that fall outside the country’s conventional medicine and are not entirely incorporated into the mainstream healthcare system. The WHO states that traditional medicine (TM) refers to the knowledge, skills and practices from indigenous theories, beliefs and experiences of different cultures being used to maintain health, as well as prevent, diagnose, improve or treat physical and mental illness (WHO 2019). The WHO further merges both terms to create traditional and complementary medicine (T&CM), which includes products, practices and practitioners (WHO 2019).

Traditional and complementary medicines are being used extensively for many illnesses such as diabetes mellitus, hypertension, human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS), cancer, asthma and pain (James et al. 2018). In the African setting, specifically, it is largely made up of local herbal products or medicines and indigenous traditional healthcare practices. Several CM products and practices have also been imported, such as acupuncture and homeopathy. Sub-Saharan Africa (SSA) is one of the regions where T&CM use is popular and has become a means on which a large population rely on it to maintain health, prevent and combat diseases, as well as treat mental, physical and social disorders (James et al. 2018).

A considerable portion of South Africa’s population prefers using traditional medicine or herbal products over conventional or Western medicine as they find traditional medicine and practices more accessible, affordable and efficient while aligning with their beliefs (Monakisi 2007). According to a review done in South Africa in 2007, it was found that trade in traditional medicines in the country was worth approximately R2.9 billion per year. In South Africa alone, it is evident that the use of T&CM is vast with at least 27 million consumers (Mander, Ntuli & Diederichs 2007).

In 2010, the Allied Health Professions Council of South Africa (AHPCSA) estimated that 1% – 19% of South Africa’s population used T&CM practices, including acupuncture, aromatherapy, chiropractic, herbal medicines, homeopathy, massage therapy, naturopathy, osteopathy, therapeutic reflexology, traditional Chinese medicine and traditional Indian medicine such as Ayurveda and Unani (WHO 2019). Complementary medicine is frequently used alongside conventional treatment. Often cancer patients become depressed and have to deal with many physical and emotional aspects of the disease, leaving them open to try T&CM to aid them in their fight against cancer (Dehghan et al. 2022). This scoping review includes the following T&CM categories used in sub-Saharan Africa: acupuncture, herbal products, massage therapy, meditation, mind-body practices, prayer, reflexology, spiritual healing, supplement use (with and without dietary modifications), various traditional medicines (African, Chinese and Indian origin), vitamins/minerals and yoga.

Since 2000, the WHO has been encouraging African nations and other low- and middle-income countries to embrace the use of traditional and complementary medicines by incorporating it into their national health systems in an attempt to improve the access to affordable healthcare (WHO 2002). However, developing a national policy and legal framework dealing with T&CM is still a great challenge for several sub-Saharan African nations because of the lack of evidence regarding its effectiveness, risks and interactions.

Patients using T&CM with poor understanding or based on misleading information may present a risk to their well-being (Mwaka, Abbo & Kinengyere 2020). In the same light, healthcare providers with insufficient knowledge about the mechanism of action of T&CM, their safety profiles, side effects and possible interactions with conventional medicines would be unable to improve the health of the general population who are T&CM users (Mwaka et al. 2020).

The prevalence of cancer is increasing worldwide, especially in SSA. Additionally, most of the cancer patients from SSA are being diagnosed in advanced stages where survival rates are poor, often prompting these patients to turn to the use of T&CM (Mwaka et al. 2020). There are, however, limited data available on aspects of complementary medicine use among cancer patients in SSA, including the types of T&CM used, effectiveness and risks of such treatments and the extent to which cancer patients use or rely on T&CM (Mwaka et al. 2020).

A systematic review, conducted by James et al. (2018), found that most patients using T&CM, whether alone or in combination with mainstream medicine, do not disclose the use of T&CM to their physicians, either because their physicians do not ask about T&CM use or the patient fears retribution. When it comes to anticancer drugs, most have a very narrow therapeutic window, and the use of herbal supplements, which a cancer patient may perceive as harmless, could interact with their chemotherapy regimen reducing its efficacy or enhancing its toxic effects (Vasques et al. 2024). It is therefore of great importance that patients disclose any T&CM use to their oncologist.

This scoping review aims to collect information about the prevalence of use, reasons for use, most common types of T&CM used, level of satisfaction with T&CM and disclosure of T&CM use to physicians among cancer patients in sub-Saharan Africa. The collection and reporting of information regarding T&CM used by patients with cancer will hopefully guide other researchers on future investigations that can be done to fill knowledge gaps; encourage more research to be conducted to determine the mechanisms of action of T&CM products, their indications, effectiveness, side effects from direct use, and interactions between T&CM and conventional treatments.

Sub-Saharan Africa consists of the 49 countries in the southern part of the African continent (Tapon 2023). Articles included in the scoping review only contained information from eight countries in sub-Saharan Africa (Ghana, Ethiopia, Nigeria, Malawi, Tanzania, Morocco, Uganda and Kenya). Conclusions were drawn based on articles analysed, thus only covering 16.3% of sub-Saharan Africa.

The use of T&CMs ranged from 14.1% to 84%. Average T&CM use is 66.7% based on the 10 articles included in the scoping review. The country with the highest T&CM use among cancer patients was Malawi (84%) and the country with the lowest T&CM use by cancer patients was Kenya (14.1%).

It is evident that the use of T&CM is common among those diagnosed with cancer in SSA, and the varying prevalence of T&CM use in different countries can be associated with each region’s accessibility to conventional medicine, sociocultural backgrounds and the importance placed on T&CM by the general population. Additionally, increased use of T&CM over the years is evidenced in two studies conducted in Enugu, Nigeria, among gynaecologic cancer patients. The study by Nwankwo et al. published in 2019 found that over a 2-year period (June 2014 to June 2016), 64.3% of gynaecologic cancer patients were T&CM users (Nwankwo et al. 2019), and the study conducted by Ajah et al. published in 2021 found 71.5% of participants made use of T&CM (Ajah et al. 2021).

The study conducted in Ethiopia by Erku (2016) found that the most common source of T&CM information was family members and friends, and the least common source used to seek information about T&CM was medical practitioners. The study done in Nigeria and Ghana reported similar findings in which most of the participants got information about T&CM from friends and family or mass media (Yarney et al. 2019). The study done in Tanzania found that more than half of respondents used herbal medicine for their current cancer disease; however, only a quarter consulted a traditional healer or herbalist (Henke, Bruchhausen & Massawe 2022). In the study done in Nigeria by Nwankwo et al. (2019), it was also revealed that most of the T&CM being used were self-administered and no professional herbalists were consulted; the products being used were mainly recommended by family and friends. A large population of T&CM users sourced products informed by friends, family or the media and do not seek help from herbalists or physicians. This presents a great challenge as herbal agents are prone to abuse among T&CM users as they are not counselled about how to use them; furthermore, it could be a potentially toxic compound when combined with anticancer treatment (Nwankwo et al. 2019).

Several cancer patients stated the reason they were using T&CM was to cure cancer. Owing to the important role traditional healers have held in the region and the large population who still have strong belief in traditional healers, it is important for healers and physicians to work together in order to deliver the best possible care to patients. Many cancer patients believe that traditional medicine has the ability to cure cancer; it is therefore crucial that physicians remind patients that traditional healing does not replace conventional anticancer treatment and all forms of T&CM need to be used with caution.

Anticancer agents are generally toxic with several side effects. Some cancer patients tend to combine herbal products with their conventional cancer treatment in an attempt to enhance well-being and manage the side effects associated with chemotherapy. However, the potential risk of interactions from herbal use may outweigh any benefit (Alnaim 2007). For example, a case report by Bilgi et al. (2010) reported that a patient taking imatinib for 7 years began displaying symptoms of hepatotoxicity upon starting to consume ginseng. Once ginseng was discontinued, the hepatotoxicity resolved. According to the study conducted by Cox et al. (2006), garlic was found to decrease the clearance of docetaxel. Despite the decrease being non-statistically significant, there is a possibility of increased adverse effects resulting from docetaxel accumulation. The pharmacokinetic study by Goey et al. (2014) concluded that St John’s wort caused a remarkable decrease in the plasma concentration of docetaxel.

In a Nigerian study, more than a third of the participants stated they used T&CM with the belief it would complement the conventional medicine and improve the outcome of treatment. A quarter of respondents also stated that they used T&CM because it was readily available and one fifth found it more affordable. This can be expected as a large portion of the African population rely on T&CM to meet their primary medical needs (Aliyu et al. 2017).

The study conducted among cancer patients in Uganda found that those patients who are dissatisfied with conventional treatment are more likely to use T&CM (Kiwanuka 2018). Respondents also stated that they turned to T&CM use in order to fulfil unmet needs by conventional therapy (Kiwanuka 2018). The growing use of traditional and herbal-based medicinal therapies may be because of the perception that they are natural and therefore do not cause any detrimental or unfavourable effects despite the lack of scientific evidence (Erku 2016).

A study conducted in Ghana found that approximately one-third of cancer participants used T&CM because they were willing to try anything. In the developing world (including Ghana), a large portion of cancer patients are diagnosed at a late stage, where many conventional treatments often fail to cure the individual (Yarney et al. 2019). The late diagnosis leads to reduced chances of cure; thus, many patients lose hope in the effectiveness of conventional treatment and turn to using or relying on traditional, complementary and alternative medicines (Yarney et al. 2019).

More than half of the cancer patients who participated in the study in Malawi used herbal medicines, even though the percentage of patients who consulted with herbalists was lower. The following herbs were commonly being reported: Terasi or Teras Juice, mvunguti (Kigelia africana), ginger (Zingiber officinale), moringa (Moringa oleifera), garlic (Allium sativum), aloe vera, avocado leaves (Persea americana) and soursop (Annona muricata). Herbal products are particularly important when looking into the impact T&CM has on cancer treatment (potential herb–drug interactions, patients delaying conventional therapies, toxic herbal products). Another problem is that a significant proportion of herbal product users state that they are often unaware of which herbs they are consuming. It was also found that many herbalists do not disclose the herbs that they supply in order to maintain proprietary rights to their herbal formulations and prevent patients from self-administering herbal products (Hill et al. 2022).

From the articles included, it was noticed that many participants reported adverse effects such as nausea, vomiting, frequent urination, diarrhoea, headache, upset stomach, skin rashes and itching.

The study conducted in Malawi by Hill et al. published in 2022 revealed relatively low satisfaction with herbal products and traditional healers. Several participants conveyed dissatisfaction because of the inability to formally diagnose cancer, control their symptoms or cure the cancer. It is common for patients to first go to traditional healers when they experience symptoms and only turn towards mainstream healthcare after traditional methods were unable to produce desired results. This may contribute to the dissatisfaction with traditional methods upon receiving a pathological cancer diagnosis (Hill et al. 2022).

Less than a quarter of cancer patients disclosed T&CM use with their medical doctor. The main reason why participants did not inform their physician about T&CM use was because their doctor did not ask. Some of the additional reasons why patients do not disclose T&CM use to their physicians are because cancer patients believe their physicians would not understand T&CM usage, disapprove of their use of T&CM or force them to discontinue T&CM treatment. The fact that a large portion of cancer patients would not disclose that they are using T&CM until they are asked makes it important for every oncologist to ask their patients whether they are using T&CM, what products they use, how frequently they use them, and the manner in which they use them. The large portion of cancer patients who believe their physicians will have a negative attitude towards their T&CAM use also highlights the need for T&CM use sensitivity training so the topic can be addressed in a safe and comfortable way with patients.

It is important for T&CM users to remember that some of the information they receive about T&CM are often based on opinions and personal experiences, not based on objective research studies. The use of natural products is commonly associated with being safer than conventional treatment; however, this is not essentially correct. Guidance from nurses and healthcare professionals is key to help patients distinguish between possible deceit and evidence-based natural products. Patients who solely believe traditional healers can cure their cancer often delay or stop standard treatment, resulting in the reduced chances of remission or cure. It is of vital importance for healthcare providers to familiarise themselves with the most commonly used T&CM treatments among cancer patients so they will be equipped to answer questions about T&CM and advise patients in the best manner possible, warning them about over-stated benefits and potential harms of a particular therapy (Mwaka et al. 2020).

From the review, the authors can conclude that many cancer patients in SSA use at least one form of T&CM during their cancer diagnosis. Reasons for using T&CM vary among patients but the most common reasons include to improve physical and psychological well-being, to cure cancer or treat symptoms, to boost immunity, to improve quality of life and because they believe in its benefits. It was found that many patients used various T&CM products concurrently with conventional anticancer treatment; additionally, very few patients disclosed the use of complementary medicine to their physician. This non-disclosure of T&CM use exposes cancer patients to potentially dangerous side effects from interactions between drugs and T&CM products. Healthcare providers need to start having more open discussions on T&CM use with their patients in order to prevent abuse of T&CM products and provide them with factual information on T&CM safety and efficacy.

There is a need for more scientific research to be conducted in order to understand pharmacodynamics and pharmacokinetics of T&CM products to successfully determine their therapeutic indications, safety and risk profiles. This will also assist policymakers who are working on integrating T&CM and conventional biomedical treatments. The inclusion of T&CM in the medical school curricula can improve the knowledge and attitudes of healthcare workers regarding T&CM use by their patients.