Malaga's false colon cancer positives were due to contamination with cleaning liquid

The Andalusian regional health ministry has already determined the cause that led to around 400 false colon cancer positives at the laboratory of Malaga's El Clínico hospital. According to official sources, the cause was contamination of the analyser system with cleaning fluid.

"The source was the analyser that performs the determination of occult blood in faeces. Following a maintenance procedure, the system became contaminated with cleaning fluid used by the equipment itself," the regional government (Junta) said.

Lab workers detected a potential error in the analyser's internal fluid system. Some faecal occult blood samples showed artificially elevated values, leading the team to classify samples as false positives.

The regional government stressed that the incident had not produced any false negatives or missed diagnoses, "as the problem artificially increased the number of positive results, it did not than conceal potential cases".

Once the lab workers detected the issue, they reviewed control procedures and "decided to repeat all the tests from that period to ensure the maximum reliability of the results".

Regional health minister Antonio Sanz addressed the case during the presentation of the summer plan for hospitals and health centres in the region on Thursday. Sanz stated that the "reaction was immediate" and that all the tests "are being repeated". He also confirmed that it was a "technical issue".

The high number of false positives raised alarm bells, allowing for the rapid detection of the exact problem. Furthermore, these samples do not affect the entire group, but only some of the people who have undergone the tests.

The regional ministry has informed the health districts this issue concerns and launched the review with the aim of contacting individuals and offering them a repeat faecal occult blood test.

The samples come from some health centres in the Costa del Sol and Guadalhorce health districts that depend on El Clínico.

The legal advisor for the patient advocacy association, Damián Vázquez, described the incident as "an unacceptable scandal". "We want explanations and full transparency," he stated in an interview with SUR.

The association has referred the matter to the provincial prosecution of Malaga for investigation.

Vázquez has requested criminal proceedings and has asked for the number of tests not performed, the list of affected patients 2023-2026, internal protocols and audits.

The patients' association has asked that the Andalusian health system immediately summon all patients with "uncertain negative" results to repeat the test and colonoscopy if necessary. The regional ministry responded that it had already initiated the procedure.

According to the Andalusian oncology society (Saom), more than 1,400 people in Malaga will be diagnosed with colon cancer in 2026. This is, in fact, one of the tumours with the highest number of new cases and prevalence in Andalucía and Spain.

Early detection is proving key to survival rates. Thanks to early detection techniques and the latest advances in cancer treatments, more than 60 per cent of patients will overcome it, 90 per cent if detection is in the really early stages.

The colon cancer survival rate in Spain has increased in recent years, reaching 64 per cent in women and 63 per cent in men.

Several symptoms indicate the possible presence of tumours: changes in bowel habits, such as a sudden shift from constipation to diarrhea or alternating constipation and diarrhea; blood or mucus in stool; unintentional weight loss that persists over time; significant weakness.

According to the Saom, early diagnosis and screening programmes, like the one that has been running in Andalucía for years, are significantly improving the survival rate and quality of life.

However, seven out of ten people in Malaga do not undergo screening despite being in the at-risk population group and receiving an invitation.

For more health-related news click here