Cancer in Zimbabwe
By Dr Brighton Chireka
On Tuesday, the 11th October 2016, I was privileged to receive the ZIMBABWE NATIONAL CANCER REGISTRY (ZNCR) 2014 ANNUAL REPORT from the ZNCR Registrar Mr E Chokunonga. I must commend the ZNCR for working so hard to provide us with a more up-to-date information on the incidence and pattern of occurrence of cancer in Zimbabwe. I am passionate about cancer as I have lost very close relatives from Cancer of the Gallbladder, Cancer of the Prostate, Kaposi sarcoma to name a few and I also have very close people that that have suffered from breast cancer as well.
Zimbabwe National Cancer Registry (ZNCR)
The registry with its limited resources is achieving a lot due to committed and determined leadership by using what it has in its hands. The ZNCR is a voting member of the International Association of Cancer Registries (IACR) and the Union for International Cancer Control (UICC). It is also one of the founding members of the East African Registry Network (EARN) which became the African Cancer Registry Network (AFCRN) in 2011. The ZNCR has provided technical support to several other African cancer registries over the last two decades. It successful hosted the 2nd Annual Review Meeting of the African Cancer Registry Network (AFCRN) in Victoria Falls in January 2014.
Cancer in Zimbabwe in 2014
In 2014 the total number of new cancer cases recorded among Zimbabweans was 7018 comprising of 4037 ( 57.5%) females and 2981 ( 42.5) males. In 2013 the total number of new cases of cancer recorded among Zimbabweans was 6548. This shows a 7% increase in cases.
The nine most frequently occurring cancers among Zimbabweans of all races in 2014 were cervix uteri (19%), prostate (9%), breast (7%), Kaposi sarcoma (7%), non-Hodgkin lymphoma (6%), non-melanoma skin cancer (6%), oesophagus (5%), liver (4%) colo- rectal (4%). Of note is that prostate cancer has risen from 7% in 2013 to 9 % in 2014 and is the second most frequently occurring cancer in Zimbabwe. The good news is that Kaposi Sarcoma has come down from 10% in 2013 to 7% in 2014.
The most common cancer in Zimbabwe is cervical cancer
The leading cause of cancer among Zimbabwe black men in 2014 was prostate (23.1%). cancer followed by Kaposi Sarcoma(11.5%). In Zimbabwean black women the most common cancer was cervical cancer followed by breast cancer.
Death caused by cancer in Zimbabwe
A total of 2 474 cancer deaths comprising 1 192 (48.2%) males and 1 282 (51.8%) females were recorded in Harare and Bulawayo in 2014. The leading causes of the deaths were cervical cancer (12%), prostate (10%), liver (8%), oesophagus (8%), breast (7%), non-Hodgkin lymphoma (6%), Kaposi sarcoma (6%) stomach (4%), lung (4%).The other cancers constituted 35% of the recorded deaths.
The most notable observation in the data for 2014 is the striking increase in the incidence of prostate cancer as mentioned above. Cancer of the prostate is now by far the leading cause of cancer among Zimbabwean males. It was also the second leading cause of cancer mortality after cervical cancer in 2014. ZNCR is now calling for epidemiological investigation about prostate cancer in view of these findings
The incidence of HIV-related Kaposi sarcoma (KS) continues to decline. The incidence of KS was half that of prostate cancer among Zimbabwean males in 2014. It is important to note that other than these two cancers (prostate and KS), the pattern of occurrence of cancer has hardly changed in recent years.
The registry gave us an analysis of cancers by stage of disease at diagnosis in 2013.The analysis showed that people were presenting very late when the cancer had spread to other parts of the body. It is now well known that the outcome is very poor when people present to their doctors too late.
The analysis by stage was also done in 2014, and the results are remarkably similar to those observed in 2013. However, most of the cases (71%) were not staged, and for those that were staged, the majority (84%) were in stage three and four. Clinicians need to make sure that they are staging the disease of the patients they manage . Information on stage is important for cancer management and is also important in determining survival.
I hope by compiling this article I am helping in raising awareness on the need to take cancer seriously and see our doctors as soon as possible. I also hope that my colleagues in the medical field in Zimbabwe will stage the disease of the patients they are managing.
What cancer staging is
According to Cancer research UK
Staging is a way of describing the size of a cancer and how far it has grown. When doctors first diagnose a cancer, they carry out tests to check how big the cancer is and whether it has spread into surrounding tissues. They also check to see whether it has spread to another part of the body.
Cancer staging systems may sometimes include grading of the cancer, which describes how similar a cancer cell is to a normal cell.
Why staging is important
Staging is important because it helps your treatment team to know which treatments you need. If a cancer is just in one place, then a local treatment such as surgery or radiotherapy could be enough to get rid of it completely. A local treatment treats only one area of the body.
If a cancer has spread, then local treatment alone will not be enough. You will need a treatment that circulates throughout the whole body. These are called systemic treatments. Chemotherapy, hormone therapy and biological therapies are systemic treatments because they circulate in the bloodstream.
Sometimes doctors aren’t sure if a cancer has spread to another part of the body or not. They look at the lymph nodes near to the cancer. If there are cancer cells in these nodes, it is a sign that the cancer has begun to spread. Cancer doctors call this having positive lymph nodes. The cells have broken away from the original cancer and got trapped in the lymph nodes. But it is not always possible to tell if they have gone anywhere else.
If cancer cells are found in the lymph nodes, doctors usually suggest adjuvant treatment. This means treatment alongside the treatment for the main primary tumour (chemotherapy after surgery, for example). The aim is to kill any cancer cells that have broken away from the primary tumour.
Types of staging systems
There are two main types of staging systems for cancer. These are the TNM system and the number system.
The systems mean that
* Doctors have a common language to describe the size and spread of cancers
* Treatment results can be accurately compared between research studies
* Guidelines for treatment can be standardised between different treatment hospitals and clinics
Some blood cancers or lymph system cancers have their own staging systems.
The TNM staging system
TNM stands for Tumour, Node, Metastasis. This system describes the size of the initial cancer (the primary tumour), whether the cancer has spread to the lymph nodes, and whether it has spread to a different part of the body (metastasised). The system uses numbers to describe the cancer.
* T refers to the size of the cancer and how far it has spread into nearby tissue – it can be 1, 2, 3 or 4, with 1 being small and 4 large
* N refers to whether the cancer has spread to the lymph nodes – it can be between 0 (no lymph nodes containing cancer cells) and 3 (lots of lymph nodes containing cancer cells)
* M refers to whether the cancer has spread to another part of the body – it can either be 0 (the cancer hasn’t spread) or 1 (the cancer has spread)
So for example, a small cancer that has spread to the lymph nodes but not to anywhere else in the body may be T2 N1 M0. Or a more advanced cancer that has spread may be T4 N3 M1.
Sometimes the letters a, b or c are used to further divide the categories. For example, stage M1a lung cancer (the cancer has spread to the other lung) and stage M1b lung cancer (the cancer has spread to other parts of the body).
The letter p is sometimes used before the letters TNM – for example, pT4. This stands for pathological stage. It means that the stage is based on examining cancer cells in the lab after surgery to remove a cancer.
The letter c is sometimes used before the letters TNM – for example, cT2. This stands for clinical stage. It means the stage is based on what the doctor knows about the cancer before surgery. The stage is based on clinical information from examining you and looking at your test results.
Number staging systems
Number staging systems usually use the TNM system to divide cancers into stages. Most types of cancer have 4 stages, numbered from 1 to 4. Often doctors write the stage down in Roman numerals. So you may see stage 4 written down as stage IV.
Here is a brief summary of what the stages mean for most types of cancer.
Stage 1 usually means that a cancer is relatively small and contained within the organ it started in.
Stage 2 usually means the cancer has not started to spread into surrounding tissue but the tumour is larger than in stage 1. Sometimes stage 2 means that cancer cells have spread into lymph nodes close to the tumour. This depends on the particular type of cancer.
Stage 3 usually means the cancer is larger. It may have started to spread into surrounding tissues and there are cancer cells in the lymph nodes in the area.
Stage 4 means the cancer has spread from where it started to another body organ. This is also called secondary or metastatic cancer.
Sometimes doctors use the letters A, B or C to further divide the number categories – for example, stage 3B cervical cancer.
Carcinoma in situ
Carcinoma in situ is sometimes called stage 0 cancer or ‘in situ neoplasm’. It means that there is a group of abnormal cells in an area of the body. The cells may develop into cancer at some time in the future. The changes in the cells are called dysplasia. The number of abnormal cells is too small to form a tumour.
Some doctors and researchers call these cell changes ‘precancerous changes’ or ‘non invasive cancer’. But many areas of carcinoma in situ will never develop into cancer. So some doctors feel that these terms are inaccurate and they don’t use them.
Because these areas of abnormal cells are still so small they are usually not found unless they are somewhere easy to spot, for example in the skin. A carcinoma in situ in an internal organ is usually too small to show up on a scan. But tests used in cancer screening programmes can pick up carcinomas in situ in the breast or the neck of the womb (cervix).
This article was compiled by Dr Brighton Chireka , who is a GP and a blogger based in Kent in the United Kingdom. Feel free to contact him at firstname.lastname@example.org and you can read more of his work on his blog at DR CHIREKA’S BLOG
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. Dr Chireka has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other healthcare professionals for a diagnosis and treatment of medical conditions. Views expressed here are personal and do not in any way , shape or form represent the views of organisations that Dr Chireka work for or is associated with.