Ottawa mother Charlotte Kessler, 36, was diagnosed with a brain tumour in 2013 and endured brain surgery and two years of chemotherapy.

Kessler says she didn't want to lose the support of her oncology team after it was over, but she was given no choice.

She eventually sought new medical treatment. "I need help," she told them. "No, I don't know what I need ... but I need help."

Kessler was paired with a new oncologist, who is now her main medical contact. She has also received support through counselling.

One in two Canadians will experience cancer in their lifetimes. There are 800,000 survivors.

Studies have shown that 80 per cent of survivors report long-term side effects like fatigue and 70 per cent report psychological impacts. About one in five have symptoms of Post-Traumatic Stress Disorder.

Ahead of World Cancer Day on Sunday, Canadian survivors are highlighting the fact that while the medical system is doing better than at ever at curing cancer, it does a poor job of providing mental health care after they get the all-clear.

Jackie Manthorne, a cancer survivor and president of the Canadian Cancer Survivor Network, says that many patients "feel abandoned when treatment ends."

"There isn't one survivor who won't tell you that they don't fear recurrence," she says. "They're dealing with an illness that they know sometimes kills people."

Manthorne says cancer can also strain relationships with partners and children.

Yet in most treatment centres don't offer any follow up for survivors, Manthorne says. "They are off on their own."

Manthorne says she'd like to see cancer patients receive automatic rehabilitation options, just like when someone survives a heart attack or stroke.

Dr. Mary Gospodarowicz, medical director of the Princess Margaret Cancer Centre in Toronto, agrees there is a gap.

"The social support is very important," she says. "It is one area of cancer that hasn't been well funded or well resourced."

With a report from CTV medical specialist Avis Favaro and producer Elizabeth St. Philip