Drug boosts survival of patients with form of non-Hodgkin's lymphoma: study

TORONTO (CP) - Adding a new drug to the standard chemotherapy cocktail can significantly boost the survival rate of patients with the most common type of non-Hodgkin's lymphoma - the fastest-rising cancer among Canadians, a study has shown.

The study by the B.C. Cancer Agency shows that the addition of the drug rituximab increased two-year survival by more than 50 per cent, compared with using only the standard mix of four chemotherapy drugs.

"What we found was that since we introduced this new treatment combination here in British Columbia, there's been a vast improvement in outcome in these patients," principal investigator Dr. Laurie Sehn said Tuesday from Vancouver.

Before the introduction of rituximab, half of patients with diffuse large B-cell lymphoma were alive two years after diagnosis; since doctors began adding the drug, more than 75 per cent of patients are alive, said Sehn, a medical oncologist at the B.C. Cancer Agency.

"So in essence, we've been able to reduce the death from this kind of cancer by more than half."

The agency, which tracks diagnosis, treatment and outcome for all B.C. cancer patients, recommended widespread use of rituximab after a 2000 European study found the drug improved survival in patients over age 60 with advanced diffuse large B-cell lymphoma.

B-cells make antibodies to fight infection by viruses and bacteria. Lymphomas are cancers of the lymphatic system, a critical part of the immune system.

The B.C. study, published in this month's issue of the Journal of Clinical Oncology, looked at 292 patients diagnosed with an advanced form of the cancer between September 1999 and August 2002, but widened its scope to patients of any age.

Using its comprehensive network of patient records, the study analysed how 152 patients treated before the introduction of rituximab fared compared to 140 treated after the drug was added to standard therapy.

"This trial, along with the original clinical trial (in Europe), has had huge implications for the treatment of patients with the most common type of non-Hodgkin's lymphoma that we see," Sehn said. "So what we're seeing is a huge improvement in outcome by the introduction of this new therapy."

Vancouver actor Richard Boyce-Sargent, 60, credits the drug with helping him beat the odds against the cancer.

A lump in his throat that altered his voice and impaired swallowing was diagnosed as diffuse large B-cell lymphoma in fall 2001. Soon after he began standard chemotherapy, his doctor said his drug regimen would be altered to include rituximab.

Today, almost four years later, Boyce-Sargent said he is feeling great and so far is cancer-free.

"After I did the chemo treatment, I started to realize that that stuff played a strong role," the father of two teenage girls said of the drug. "I'm here and I'm healthy and I'm just grateful."

Non-Hodgkin's lymphoma is the fifth most common cancer in Canada. This year, an estimated 6,400 Canadians will be diagnosed with the disease; about 3,000 will die.

It is also the fasting-rising type of cancer, although doctors don't know why, said Sehn. "We've seen a continuous increase in the incidence of this type of cancer every decade."

Patients may develop a lump, or swollen lymph node, in the neck or groin. However, some people who develop the disease arrive at their doctors' offices with no obvious lump, just vague flu-like symptoms - including fatigue, fever and feeling unwell.

Rituximab, marketed by Roche Canada under the brand name Rituxan, is a monoclonal antibody - an engineered protein that targets cancer cells and ratchets up the immune system's ability to destroy those cells.

"There isn't any other treatment in this particular type of lymphoma that's shown improved survival in the last 25 years," said Dr. Michael Crump, lymphoma site leader at Toronto's Princess Margaret Hospital. "So we regard the addition of rituximab to chemotherapy for patients with diffuse large cell lymphoma as a major advance."

The drug - which is now used by doctors across the country for these patients - also works without bumping up the side-effects of chemotherapy, which can include a low blood count and infection, said Crump. "That also makes it very unusual."

British Columbia is one of the few places in the world where such a study could have been done because it has invested in comprehensive databases to track cancer patients within its population. No other province has a comparable system, Crump said.

Sehn agreed it gives B.C. doctors a valuable tool for assessing new weapons against cancer.

"By doing a study like this, we're actually able to measure the impact of these new treatments out in the real world and it lets us monitor the real progress that's being made in cancer treatment."