A third of patients are waiting too long for urgent cancer treatment to begin in Northern Ireland, official figures show.
Targets for waiting times have again been missed and campaigners said efforts to encourage early diagnosis had been compromised.
Last September 64 per cent of patients with an urgent GP referral for suspected cancer started their first treatment within 62 days, down from 70 per cent in July.
The target is 95 per cent and all health trusts missed it for the last quarter, statistics from the Department of Health showed.
Roisin Foster, chief executive of Cancer Focus Northern Ireland, said: "Our message that early diagnosis and treatment saves lives is being compromised by these very worrying statistics."
The percentage of patients first seen within 14 days following an urgent referral for suspect breast cancer rose from 85 per cent in July to 96 per cent in September.
But Ms Foster said the continuing failure to meet targets for patients awaiting treatment was a major concern.
"We need targeted work to reduce cancer patient waiting times immediately, to lower patient anxiety and the fear that their cancer is progressing while they wait.
"We know that our health trusts are under extreme pressure.
"Waiting times have already been addressed as part of the Bengoa report and we want to see those recommendations implemented as soon as possible. For many cancer patients time is not a luxury they can afford."
The Bengoa report was commissioned by ministers seeking advice on how to improve services, cut waiting lists and care for an ageing population. It said an increased number of emergency or unplanned but urgent admissions affected hospitals' ability to deal with elective or planned care, meaning longer waiting times as priority was given to urgent care.
Alliance Assembly member Paula Bradshaw called for a cancer strategy and a waiting list plan as well as a long-term shift towards primary care which would reduce referrals.
She added: "We heard at the start of this term there would be a joined-up approach and the minister would work together for the common good. What we actually have is delay and miscommunication. This comes at a real human cost."
A statement from the Patient and Client Council said it was concerned and disappointed.
"The health service needs to ensure not only timely treatment but also accurate information is provided to patients on when they will receive that treatment."
Health minister Michelle O'Neill said overall cancer survival rates were better than ever, improving from 43% in 1993-99 to 54% in 2005-09.
She added: "This improvement in survival is, in no small part, due to earlier diagnosis as well as access to better treatment and we therefore need to build on this.
"My focus is on ensuring that the trusts improve the performance of our existing high-quality cancer services so that patients receive the best possible service during the diagnosis and treatment of their condition."
She said excessive waiting times were unacceptable.
The Health and Social Care Board is working with trusts to reduce the number of patients waiting more than 62 days and cut the length of time all patients are waiting.
"I want this work to produce similar improvement to the performance that the trusts have achieved in respect of the waiting times for the 14-day target for urgent GP referrals for suspected breast cancer."
