The national programme for the early detection of bowel cancer is set to restart across Croatia by the end of the year, with a new and simpler FIT test. The test is a quantitative immunochemical test for hidden blood in the stool, which is simpler to use and more sensitive than the previous guaiac test.
In the pilot project in Zagreb, which sent out test kits to 5,000 people in April, the current response rate is 66 per cent. Natasa Antolic, head of the Department of Bowel Cancer Screening at the Croatian Institute of Public Health (HZJZ), says that the current proportion of those tested is 66 per cent, and that the final response is expected to be even higher. The sample collection is still ongoing, so the final results of the pilot project are not yet known. So far, 2,951 people have had negative, and 352 positive, results.
In the previous sixth cycle, in which the old guaiac test was used, 37 per cent of those invited took part. The previous kit contained three cards on which a stool sample was applied, while the new one contains two plastic containers with a sampling stick. The samples are taken from two consecutive bowel movements and sent by post to the HZJZ. The reading will be centralised and automated, with the Institute currently having two devices that can process up to 300 samples per hour. It is calculated that around 170,000 people will be tested annually, which means processing approximately 340,000 samples a year.
According to experience from other countries, the simpler sampling and application of the FIT test could increase the screening response by around 10 per cent. The goal is for at least 45 per cent of those invited to take the test in the next phase of the sixth cycle, while a response of around 60 per cent, as seen in Slovenia, would be ideal. The test does not diagnose cancer, but detects hidden blood in the stool. Those with a positive result are referred for a colonoscopy to determine the cause of the bleeding and to potentially detect polyps, adenomas or carcinoma. Colonoscopy is both a diagnostic and therapeutic procedure, as pre-cancerous changes can be removed during the examination and sent for histopathological analysis.
According to the guidelines the programme has followed, people with a positive result should undergo a colonoscopy within six to eight weeks. Hospitals carrying out screening colonoscopies must have a specific contract with the Croatian Health Insurance Fund (HZZO), committing to provide enough appointments, staff and equipment. These are additional appointments that should not reduce the availability of diagnostics for other patients. The quality of the procedure is monitored by an HZJZ working group, and screening colonoscopies can be performed by experienced doctors with at least 200 previously performed colonoscopies. In Croatia, more than 60,000 colonoscopies are performed annually in routine practice. Given that the test is more sensitive, a higher number of positive results is expected, and thus more screening colonoscopies. Antalic notes that the early detection and removal of pre-cancerous changes could reduce the number of late-stage cancers and emergency operations in the long term.
People with a positive result will be notified by the coordinators of the county public health institutes, and their general practitioner will also be informed. The coordinator will then arrange an appointment for the screening colonoscopy and provide instructions for preparation. HZJZ expects the mass invitation of citizens to continue by the end of the year, after the necessary technical and organisational conditions are met. In the next phase of the sixth cycle, around 400,000 people born between 1952 and 1962 are to be invited. Citizens will first receive an invitation letter by post, and those who agree to participate will receive the sampling kit by post.
The stool testing, which was part of the national programme, was completely suspended in 2024, with residents able to have the test for hidden blood in the stool carried out via a referral from their general practitioner. The programme does not have a single centralised funding source. HZJZ funds the tests, printed materials, postage, education, promotional activities and quality control. The cost of the tests, materials and postage in full is estimated at around 1.5 million euros per year, while the colonoscopies and histopathological diagnosis are funded separately by the hospitals that have a contract with HZZO to carry out the screening. The first assessment of the new model could be made six months after the start of the mass invitations, while the assessment of its impact on the number of detected adenomas and carcinomas will take several years.
Bowel and rectal cancer is one of the most common malignant tumours in Croatia. According to the data from the Cancer Registry, in 2023 it was diagnosed in 3,820 people, including 2,262 men and 1,558 women. It was the third most common among men and the second among women, and when looking at both sexes combined, it was the most common cancer in Croatia. Bowel and rectal cancer was the second most common cause of death from malignant diseases in 2024. 1,933 people died from it, 1,136 men and 797 women. HZJZ notes that mortality from this disease has been falling in recent years in both sexes.
