Nearly 1,500 north-east cancer patients have had to leave the area for treatment in the last three years.
Exclusive new figures have revealed 1,442 people were sent elsewhere for potentially life-saving surgery.
NHS Grampian has long battled to recruit staff, drafting in locums to tackle the waiting list and ensure those needing urgent treatment are seen.
Waiting times hit their highest level last year, with patients facing a wait of 190 days compared to 169 in 2015/16 and 168 in 2016/17.
Last night, the health board stressed there were other reasons why people may choose to have their treatment outwith Grampian.
A spokeswoman said it could be down to personal preference, a patient wanting a second opinion from a known expert in a particular field or the health board not being able to provide a certain treatment.
According to the figures, patients most frequently travelled elsewhere for specialist chemotherapy and blood transfusions.
Jamie Weir, a retired NHS Grampian board member and spokesman for the patient care group PACT claimed that the figures proved there is “insufficient” resource available for many people battling the disease in Aberdeen, Aberdeenshire and Moray.
He said: “For a number of years as shown by the data, there has been a considerable number of patients who have had to travel out Grampian for cancer treatment.
“Whilst some may have done this due to desire, absence of specialist care or other personal wishes, it would seem that for the remainder, there is insufficient local resource to adequately serve the needs of Grampian cancer patients.
“Funding for Grampian has been an issue for decades.
“We remain the lowest-funded health board in Scotland and the knock-on effect of years of underfunding are now showing to the detriment of patients and also to staff with their stress levels and working environments.
“The chronic lack of resources over many years combined with the continued underfunding when compared to other health boards does not bode well for improving the current situations for patients.”
North East Labour MSP Lewis Macdonald acknowledged that in some cases, there are limited experts in the local area.
“Some cancers are so unsual that there will only ever be on or two hospitals across Great Britain with the expertise required to help patients, so some travel is inevitable,” he said.
“Most people who are seriously ill want to be treated as close to home as possible, which is why the large number of specialities and services at Foresterhill is so valuable.”
Peter Chapman, North East Conservative MSP, believes the issue has been worsened by staff shortages.
He said: “Clearly, many patients will be willing to travel outwith the local area if it means they will be treated more quickly.
“However, people in the north-east should not have to travel to the Central Belt for treatment.
“If we had a properly funded, and fully staffed local NHS, these numbers would be dramatically reduced.
“The buck stops with the SNP on this – it is high time Nicola Sturgeon treated the north-east as a priority.”
Last night, an NHS Grampian spokeswoman said: “It has always been the case that some Grampian patients are treated outwith the region, but very few are cancer patients.
“Patients may be seen elsewhere if they are referred for specialist treatment or to a national specialist centre.
“It may also be the case that they require emergency treatment.
“Some patients can also be offered the option of treatment elsewhere in order to be treated sooner.”