A mobile lung screening unit has been damaged by vandals who cut the cables to its generator.
Patients booked in at the NHS Targeted Lung Health Check unit at the leisure centre in Withernsea in East Yorkshire are being advised to turn up as normal.
The Humber and North Yorkshire Cancer Alliance said it was doing "everything it could" to keep appointments.
It said the incident had been reported to Humberside Police, which is investigating.
A spokesman for Humber and North Yorkshire Cancer Alliance said: "We can confirm that the generator cables have been cut and the incident has been reported to Humberside Police.
"We are doing everything we can to keep any disruption to the lung health check service to a minimum and will contact any patients whose scheduled appointments need to be rearranged."
Last year, it said about 40,000 people living in the East Riding of Yorkshire would be invited for a lung health check, as the mobile unit moves around the region.
The incident comes weeks after a mobile breast screening unit was removed from the town after power cables were stolen.
Thieves targeted the NHS service in the car park of Withernsea Hospital, on 24 November and 7 December 2023, police said.