However, he has stopped short of promising immediate intervention.
"I’m acutely aware of issues in the Southern District Health Board," Mr Little said.
"I’m concerned about the extent of waiting times.
"It’s more likely in the SDHB than other [health boards] that diagnosis comes very late and therefore treatment is late."
SDHB waiting lists for cancer detection and treatment are at record levels and more than 150 people are waiting for radiation oncology treatment.
The board has been failing to meet both 31-day and 62-day cancer treatment targets.
Patients advocate Melissa Vining this week called for Mr Little to step in, asking how many patients had to die before anyone took action.
Ms Vining, widow of Winton farmer Blair Vining, whose petition for better cancer care led to the Government setting up Te Aho o Te Kahu, the Cancer Control Agency, said the situation in the South was outrageous.
This week, agency chief executive Prof Diana Sarfati demanded action from the SDHB.
Prof Sarfati said she was deeply concerned about the increase in waiting times and expected changes would be made quickly.
Mr Little said he was receiving regular updates.
"This is high on my attention list," he said.
A new diagnostic CT scanner for Dunedin Hospital is expected to arrive in August and SDHB chairman Pete Hodgson has pushed for more MRI scanning to be offered.
Mr Little expected the new CT scanner would relieve some of the pressure, but he signalled broader issues such as efficiency and service configuration might also need attention.
Mr Little said variations in waiting times throughout New Zealand was one reason for pursuing health reforms.
The Government plans to replace district health boards with two national agencies, one of them a Maori authority, and regional branches.
Medical specialists union Apex national secretary Deborah Powell said radiation oncologists were "incredibly frustrated and helpless" that systems and budget issues seemed to be failing their patients.
The SDHB seemed to be incapable of responding to and dealing effectively with long-running cancer treatment waiting list problems, and this had contributed to staff burnout, Dr Powell said.
It is understood at least one complaint about harm being caused to a patient due to delays in getting a scan has been lodged in recent days, as well as complaints about delays in receiving first specialist appointments for cancer treatment.
SDHB chief executive Chris Fleming has said the board was very concerned about oncology service delays and resulting distress for patients and clinicians.
— Additional reporting Mike Houlahan