Experts call for early cancer screening, opinion divided on better methods

Thursday February 16 2017

As the world marked the World Cancer Day on February 4, this time under the theme “We can, I can,” the appropriate screening methods remained contentious.

This year’s theme encouraged countries to explore how every individual can go through screening to detect cancer early enough to turn the tides against the disease.
East Africans marked the day with controversy surrounding recommended screening methods.

Take the Protein Specific Antigen (PSA) test used for prostate cancer test in men, which though commonly used has been dismissed by experts. Studies show that in most people, the test results are misleading. Since prostate cancer is associated with elevated PSA protein levels in the blood, men with higher scores are at times thought to have the disease when they actually don’t have it.

This is because some medicines and other conditions such as inflammation or enlargement of the prostate can also cause elevated PSA levels.

“With all these uncertainties, I fear taking the test as I may end up being treated for a disease that I am not suffering from,” said Michael Otieno, 45-year-old accountant in Nairobi.

Asim Shaikh, an oncologist at the Aga Khan University Hospital in Nairobi, said people should not worry about getting wrong results since PSA is just used for screening for prostate cancer but not for diagnosing the disease.


If PSA levels are high, and other possible causes for it have been ruled out, another follow-up test known as a biopsy is conducted to make the right diagnosis.

During this process, tissue samples are extracted from the prostate gland and examined to determine whether they are cancerous or not.

Tests still recommended

New technology is improving the diagnosis process. Among those with elevated PSA levels, a recent Lancet study found that MRI scans can be used to determine those likely to have the cancer, and thus in need of a biopsy, from those that do not require it.

Despite the controversies surrounding them, PSA tests are still recommended for men above 50 who are at risk of the disease. The age reduces to 45 for those with a family history of prostate cancer.

“But in each of these cases, doctors should first inform people about the benefits and disadvantages of the tests so that they go in knowing what to expect,” said Dr Shaikh.

Another bone of contention is the mammogram, which is recommended for early screening and detection of breast cancer for women above 40.

A Dutch study published in Internal Medicine found that one out of every three women with breast cancer detected by a mammogram is treated unnecessarily. This is because some of the tumours it detects are slow-growing and harmless. These are lumps that may never grow to a level of causing the disease in the lifetime of a woman.

“Imagine getting exposed to the radiation that comes with mammogram screening, undergoing surgery and suffering the side-effects of chemotherapy and radiation treatment for a tumour that may have never harmed you. It can be devastating,” said Mercy Wangui, a mother of two in Nairobi.

Accuracy of screening

Unlike prostate cancer, where early screening with PSA tests does not necessarily improve treatment and survival, early screening of breast cancer with mammograms saves lives, says Dr Shaikh.

“At the moment, the benefits of mammograms far outweigh the disadvantages. So women shouldn’t ignore them.”

He added that the accuracy of the screening technique has also increased with the development of digital mammograms with superior image quality.

Aside from mammograms, ultrasound scans are also used to screen breast cancer. Since the latter method does not use radiation, some women opt for it.

Dr Shaikh notes that one screening method cannot replace the other since each is used for a specific purpose.

He said ultrasound work better for women below 40 because as they are equipped to navigate the dense breast tissue, common among women in this age group, and identify any hidden lumps or tumours.

But for older women with less breast tissue, the mammogram is the ideal screening method.

Despite the rollout of HPV vaccines in most East African countries, Dr Shaikh noted that pap smear tests, which screen for cervical cancer, are still important for sexually active women.

“The vaccine only protects people against a few viruses that cause the cancer. So another virus that isn’t covered can still cause the disease.”

Philip Ouma, patient support manager at Faraja Cancer Support Trust in Nairobi observed that going through cancer screening is not an easy task for most people.

“People therefore need counselling and lots of support or encouragement from friends and families before undergoing any check-ups,” said Mr Ouma.