One-year survival rates are below the national average in 14 London CCGs. NHS England estimates that 1,000 people die each year due to cancer diagnosis delays.
The five-year strategy called for extra GP training to spot cancer symptoms earlier.
Londonwide LMCs medical director Dr Tony Grewal said GPs were being blamed for factors outside of their control and without clear evidence.
‘The factors that have produced poorer figures for London than the rest of the country are incredibly complex. To highlight GPs as a significant contributor to this is unfair, it’s not evidence-based and it's also extremely unhelpful.’
He said a delay of a week or two getting a GP appointment would not be ‘clinically significant’ in the diagnosis of cancer.
Dr Grewal said: ‘We are blamed for A&E pressures, for unscheduled attendances and poor rates of early cancer diagnosis, when the evidence is limited or absent and when the only result is to reduce the trust between doctor and patient, and to knock the morale of a profession that delivers excellent care a million times a day, amazingly cheaply.’
Extra training would be appropriate if NHS England presented evidence that GPs were not responding to red flags or warning combinations of symptoms, he said. ‘Give us evidence of where GPs need to improve, and we’ll do so willingly and rapidly.’