Jill Anzarut says she is considering paying $40,000 to receive Herceptin treatment. (CBC)

The Ontario Ombudsman is investigating after the Ministry of Health refused to pay for a cancer drug for a Toronto woman whose tumour was deemed too small.

André Marin's announcement Friday comes after the provincial health insurance program determined a half-centimetre tumour in Jill Anzarut's breast didn't meet its standards to qualify for funding for trastuzumab (brand name Herceptin).

If Anzarut lived in B.C., Alberta or Saskatchewan, medicare would pay for the drug for a tumour that small.

Herceptin funding is limited to patients whose tumours are larger than one centimetre, because the guideline is based on clinical trials, and nearly all were conducted on women with larger tumours, according to Cancer Care Ontario.

Marin said he's reviewing the case after receiving a complaint from Anzarut on Feb. 28

"Based on our informal interviews with oncologists and officials from Cancer Care Ontario and the ministry, I’ve determined that this case raises issues serious enough to warrant a systemic investigation," he said in a statement.

His office will investigate whether the ministry's decision was "informed and reasonable."

Anzarut, a 35-year-old mother of two, learned last Thursday that her appeal to secure funding for the drug was denied.

Criteria being studied

Ontario Health Minister Deb Matthews said later that making an exception in Anzarut's case would be unfair  to people in similar circumstances who don't get their stories in the media.

Matthews said Anzarut and others with small tumours have other drug and treatment options, adding it shouldn't be up to politician to decide who gets a drug and who doesn't.

Diane McArthur, who heads Ontario's public drug program, has also said she has asked experts to look for any additional evidence that might change the province's guideline for Herceptin.

In the meantime, Anzarut says she's considering paying to have the drug administered through a private clinic — at a cost of about $40,000.

Herceptin is an antibody that blocks a protein on human skin cells — the human epidermal growth factor receptor 2 (HER2).

It is thought that excessive amounts of the protein HER2 increase the growth of breast cancer.

Advocates say early use of Herceptin can be extremely effective in battling the disease.

With files from The Canadian Press