A global clinical trial involving nearly 13,000 patients in hospitals across the US, Europe and Asia has, in part, overturned existing standards which have recommended patients have six months of chemotherapy.
In patients with stage three colon cancer, where the disease had spread from the initial tumour to the lymph nodes, a three month regimen appeared to be just as effective for many patients.
Since 2004 standard treatment for these patients has recommended surgery followed by treatment with chemotherapy agent, oxaliplatin, to suppress the cancer’s return – so-called “adjuvant therapy”.
However oxaliplatin is toxic to nerve cells and extended treatment increases the likelihood of patients being left in with permanent pain, numbness and tingling.
This is in addition to other side-effects of chemotherapy including nausea, fatigue and diarrhoea.
“What gratifies me about this work is its impact on patients,” said Dr Anthony Shields associate center director of the Barbara Ann Karmanos Cancer Institute and a professor at Wayne State University School of Medicine.
“I’m already using the new standards in my practice for lower-risk colon cancer patients, which saves them a lot of time in treatment, and also prevents the toxic effects of six months of chemotherapy.
“There are about 400,000 patients worldwide each year who can be considered for post-surgical treatment with oxaliplatin-based therapy, so the findings will have a large impact.”
While the treatment decisions for each patient will have to be made individually, the authors say that the findings could provide a substantial improvement to the burden of treatment for patients and savings for health systems.
Colon cancer is the third most commonly diagnosed cancer in the world, and its impact is growing.
Previous studies have predicted that by 2030 the impact of the disease will have increased by 60 per cent, leading to 2.2 million cases and around 1.1 million deaths.
For this new study the researchers recruited 12,384 stage three cancer patients as part of a concerted effort investigate the benefits and limitations of treatments aimed at keeping the cancer at bay.
They were involved in six individual trials and randomly assigned to receive either a three month or six month therapy with oxaliplaitn in combination with another recommended chemotherapy drug fluoropyrimidine.
The study, published in the New England Journal of Medicinefound significant benefits from the shorter treatment in cutting negative side effects patients would endure.
But it only found marginal survival benefits, an increased survival of 0.9 per cent, on the longer treatment thought this might have been down to chance and was of “limited clinical relevance”.
Survival was better with six months of treatment for higher risk patients, whose cancer had spread to more than four lymph nodes or have grown further into the colon wall.
The authors write the findings are the “definitive body of evidence on how to treat these patients, adding: “As expected, a shorter duration of adjuvant therapy was associated with a significantly lower incidence and severity of adverse events, especially neurotoxicity, but also symptomatic side effects...These benefits have to be counterbalanced against any potential loss of efficacy [of the treatment].”
Deborah Alsina MBE, Chief Executive of Bowel Cancer UK and Beating Bowel Cancer, says: “This trial is so important because it is potentially practice changing.
“We hear every day from bowel cancer patients about the tough side effects of chemotherapy.
“If this is incorporated into standard practice it would mean that people could finish their treatment sooner, avoid those debilitating often long term side affects and therefore enjoy a better quality of life in the future. This is positive news for patients.”
The Independent
More about: chemotherapy
