The final report into the oncologist's off-protocol chemotherapy dosing at outreach clinics in western NSW has identified 28 bowel cancer patients who were given flat doses of carboplatin, or reduced doses of the oral chemo drug capecitabine.

The report released Tuesday also criticised the local health district's oversight, stressing the debacle should not be characterised as the isolated actions of a lone doctor.

Dr Grygiel was a fly-in, fly-out medical oncologist in Orange and Bathurst between 1989 and 2012. The inquiry investigated cases of carboplatin dosing between the end of 2010 and March 2013, noting pharmacy records prior to 2010 no longer existed.

The inquiry found no evidence of a documented rationale for the dose reductions.

During his interview for the inquiry, Dr Grygiel indicated he sought to reduce toxicity in his more frail patients, and that every patient had signed a consent form for chemotherapy. The inquiry found none of these consent forms in the medical records.

In one instance, when a pharmacist queried a dose, Dr Grygiel wrote in an email "tell them to mind their own business".

But the inquiry was also critical of the WNSWLHD.

"[T]his issue should not be characterised only as an issue about an individual's clinician's prescribing," the report read.

"It is clear to the inquiry that there are issues relevant to the LHD."

Governance issues had allowed the practice to continue, including a lack of escalation processes, the LHD's failure to engage effectively with Dr Grygiel and no evidence of systems to ensure protocols were adhered to.

The inquiry did not have access to all the oncologist's prescribing, specifically for the oral prescription chemotherapy drug capecitabine, which is available from community pharmacies.

"The problem was because Doctor Grygiel was working as a private doctor with just a room in the hospital he wasn't on the staff and his prescriptions as I understand it went to local pharmacists to be filled," said Health Minister Jillian Skinner on Tuesday.

Professor Currow said the number of patients affected could rise as more records are found. 

"We expect that that number wil rise but it will rise modestly from here. It's quite possible [it could rise by one third]," he told reporters at a press conference on Tuesday.

The findings brings the total number of affected patients to more than 130, including over 100 head and neck cancer patients at St Vincent's Hospital in Sydney.

But the investigators, lead by chief executive of the Cancer Institute NSW Professor David Currow said they could not determine how the treatment regimen affected these patient's outcomes.

"Establishing a causal link between having received a substantially reduced dose of capecitabine and subsequent outcomes (disease recurrence and death) is not possible for individual patients," the report read.

"If a patient received a lower dose, it is impossible to tell what the outcomes would have been had he or she received a dosage according to a currently available protocol," it continued noting many factors affect outcomes, and cancer can recur even with optimal treatment.

The inquiry urged Western NSW Local Health District to contact all the underdosed patients and apologise for the added uncertainty regarding the likely effect of their treatment.

In August, Professor Currow delivered scathing report into Dr Grygiel's prescribing at St Vincent's Hospital in Sydney found St Vincent's Hospital misled the public and the government over the chemotherapy dosing scandal.

A senior staff member resigned over the issue.

Ms Skinner said NSW Health would implement all 16 recommendations in the report.

"The NSW Government will allocate $6 million over three years to roll out new software in public hospitals to ensure chemotherapy prescribed in electronic prescribing systems is delivering evidence-based treatment. This will allow clinical practice to be monitored, with particular emphasis on any changes in the first doses of chemotherapy.

"In addition, $1.5 million has been allocated to enhance rural cancer services in Western NSW Local Health District," Mrs Skinner said.

The under-treatment of chemotherapy patients in NSW hospitals is the subject to a parliamentary inquiry, amid warnings that improper treatment could be found to extend to hundreds more patients.

The state government and Mrs Skinner, had resisted calls for a special commission of inquiry but the upper house agreed in August to instead initiate a select committee to inquire into the treatment of patients of Dr Grygiel and that of another Sydney oncologist, operating at Sutherland and St George Hospitals.

Greens health spokesperson Jeremy Buckingham accused the health minister of downplaying the issue.

"At every juncture, this scandal as grown, more patients are impacted and the scope of the investigation has proved to be too narrow," Mr Buckingham said.

"The report released today has found serious and alarming clinical governance issues in the NSW Health system, including a failure to keep adequate records and important clinical protocols being ignored.

"It is wrong for Minister Skinner to try to wash her hands of the actions of Dr Grygiel simply because he was a private practitioner, when the report makes it crystal clear that this is not just about one bad doctor; it is about the governance of the NSW Health system of which she is in charge," he said in a statement. 

Western NSW patients or families who have ongoing concerns about their treatment under Dr Grygiel should contact the local Cancer Inquiry Line on 6369 8808 for a confidential conversation or emailWNSWLHD-CancerInquiry@health.nsw.gov.au.

Dr Grygiel's lawyer has been contacted for comment.