At least 27 people were recorded as having suffered harm in the first two months of this year while lingering on the Southern District Health Board's cancer treatment waiting list.
Three became so sick they became unfit for treatment while waiting.
Documents released to the Otago Daily Times yesterday through the Official Information Act show that clinicians raised the alarm about unacceptable waiting lists for cancer treatment for southerners as least as early as January, although it took until May for the SDHB to approve outsourcing cancer treatment to address a problem one board member had earlier called "shameful".
A "Medical Oncology Harm Register" was drafted for SDHB chief executive Chris Fleming, which showed in February that 27 people were considered as having suffered harm due to medical oncology waiting times.
Of those 27, 11 had had a prolonged delay to start curative treatment, two a prolonged delay to start palliative treatment, and nine had had additional tests or interventions delayed.
A further two people needed hospital admission due to their symptoms.
By March the Cancer Control Agency was taking a keen interest in the situation in the SDHB, as statistics showed it was one of the worst-performing cancer treatment locations in New Zealand.
"Cancer care in the SDHB is fragmented, prolonged due to multiple bottlenecks, and lacks key performance indicators and quality assurance,'' a March report prepared for the agency said.
"Outcomes in the SDHB are therefore poor for people with cancer."
The report said lung cancer patients in the SDHB region had the worst outcomes in New Zealand, at a 7 per cent lower survival rate than the national average.
Also, southern breast and prostate cancer patients due to receive radiation oncology treatment were waiting on average double or more the target of four weeks for a first specialist appointment.
At that time 123 patients were waiting for treatment, for an average 10-14 weeks.
The waiting list eventually climbed to 157 people: the most recent SDHB board meeting was told it was now 115, still well over the target of 70.
Surgical wait times for specific cancers such as urology, colon cancer and upper gastrointestinal cancer were excessive, and not all relevant clinicians were attending meetings to discuss treatment plans.
Cancer Society Otago and Southland division chief executive Rachael Hart said the society was concerned by any delays to treatment, but the wait times local people were enduring were an ongoing concern.
"It's heartbreaking," she said.
"We don't know what the effect of waiting has on the progress of each individual tumour, but we do know it is extremely worrying for people and not good for their own wellbeing, let alone their cancer."
The Cancer Society first raised fears southern cancer treatment times were too long two years ago and it was distressing that the situation seemed to be getting worse rather than better, Hart said.
"We keep talking to the DHB about what they are doing to meet their targets, we see it as a really high priority for people across the region."
Last month the SDHB approved outsourcing treatment of up to 130 breast and prostate cancer patients at St Georges private hospital in Christchurch.
Hart said she had heard anecdotally that all patients who had been offered treatment in Christchurch had accepted, although travelling far from family and support systems had been stressful for many.
"Some breast cancer patients have been separated from their children during school holidays ... people are choosing treatment over being stuck on the waiting list, but it doesn't necessarily mean it is good for their wellbeing."