Negligent Delay in Diagnosing Melanoma

6 Min Read

Paul Sankey - Enable LawCases involving the negligent delay in diagnosing cancer can be very complex, so how do the courts decide whether there is a claim? One example is a case involving delay in diagnosing malignant melanoma – a form of skin cancer.

A Melanoma Case: JD v Mather

One recent case is JD v Mather. JD became aware of a growth in his right groin in mid-2005. It was growing, started to itch and bled when he scratched it. So went to see his GP on 8th March 2006. Unfortunately his GP misdiagnosed it as seborrhoeic wart, something far less concerning.

The lesion carried on growing, and on 16th October 2006 he went back to the surgery. This time he saw a different GP, also confusingly also called Dr Mather (he was the first GP’s father). By then it was large and measured 15mm by 20mm. The doctor thought it might be a malignant melanoma, so he removed it by curettage and then sent it for histological examination.

The histology suggested a malignant melanoma.

The GP referred JD urgently to a dermatologist at Stepping Hill Hospital. He was seen on 27th October 2006 and then 3 days later by a plastic surgeon. Unfortunately the GP has not removed all of the melanoma from JD’s groin, and on 14th November 2006 the rest was excised at the Christie Hospital.

JD brought a claim against the first GP, who admitted breaching her duty in failing to diagnose melanoma, but did not accept that the delay had caused any harm.

Sadly by the time the case came to trial JD had advanced Stage IV cancer which had spread to his lungs, and hs prognosis was very poor. The question was: how much had the delay contributed to the poor outcome? In other words, what would JD’s prognosis have been had he been diagnosed in March 2006?

There are many clinical negligence claims – particularly those involving cancer – where the most difficult issue is whether a delay has made a difference to the outcome. This was one.

Staging Melanoma

In melanoma cases there are several key factors to consider in working out what someone’s prognosis would have been at an earlier stage.

(a) Breslow Thickness

Breslow thickness is the vertical distance from the surface of the skin to the lowest cancer cell, but the difficult issue in this case was that the second GP had removed the melanoma but left some behind. The part he removed was 5mm, and the part removed at The Christie Hospital was 2.8mm. Unfortunately no one could know the thickness of the original lesion in March 2006. The judge accepted evidence that it was 3-4mm.

(b) Ulceration

An ulcerated tumour is one where the surface is bleeding or oozing. There is a different between ulceration from the effect of the cancer itself (which is significant) and ulceration from some other form of injury (which is less so). A melanoma can bleed or ooze because of trauma – cuts, scratching, insect bites or surgery. There is some dispute in the literature as to how easy it is to distinguish the two different types. Here the evidence as to whether or not the melanoma had malignant ulceration in March 2006 was complex. There were different indications in the descriptions given to it at different times and the experts disagreed. However the judge accepted that it was.

(c) Spread to the Lymph

Another factor is whether the cancer has reached one or more lymph nodes, and if so whether it is palpable (apparent to touch) or only visible under the microscope. Where a cancer has spread to the lymph by the time of diagnosis, it is difficult to know whether it would already have spread at some earlier stages when there was a failure to diagnose it.

However there is research evidence which, although not perfect, helps. There are studies suggesting that melanomas of a certain thickness and degree of ulceration have, say, a 30% chancer of spreading to the lymph. There are other studies indicating what the average time is from detection of the tumour to relapse. In this case the court accepted that it would be rare for a tumour which had not spread to give rise of palpable lymph nodes within 7-8 months. The judge therefore concluded that it had already reached by the lymph by March 2006 and was already palpable.

(d) Distant Spread – Metastases

Spread to other parts of the body (metastases) usually means the prognosis is poor. In this case, it was agreed that the cancer had not spread (except to the lymph) by the time of diagnosis.

The Staging of JD’s Melanoma

Given these different factors the judge found that in March 2006 the lesion was ulcerated and had spread to at least one lymph node. It had been Stage IIIB (using a staging system known as AJCC) and by October 2006 had become Stage IIIC. Research suggests that the chance of surviving a Stage IIIB cancer was under 50%. The parties agreed.

Delaying in Diagnosing Melanoma: What is the Loss?

The way the law works can seem harsh at times. The fact that the chance of survival has dropped does not give rise to damage unless the person can show that:
1. but for the negligence they would probably have survived; and
2. as a result of the negligence they will probably not.

The law regards an event as probable if the chances of it happening are more than 50%. So a person whose prospect of survival was 51% would probably have survived in the court’s eyes. Someone whose chance of survival was only 49% would probably not have survived. If a delay causes the chance of survival to reduce from 51% to 49%, it has probably caused their death. If it causes the chance of survival to drop from 49% to 1% it probably has not – even though their death is now a near certainty.

The courts will however award damages for any extra pain, suffering, financial loss and loss of life expectancy resulting from a delay.

In this case the court heard evidence as to how long on average people survive with a single melanoma Stages IIIB and IIIC. The average for Stage IIIB was 7.5 years and the average for Stage IIIC was 4 years. JD had in fact done better than average. However the judge accepted that the delay in diagnosis deprived him of 3 years. The court in this case did not decide how much his damages would be – it was only dealing with limited issues. The parties were asked to agree what the damages should be.


Cases involving the negligent delay in diagnosing melanoma can be very complex. There are often difficult issues as to how serious a tumour would have been at an earlier stage. Experts from a number of different disciplines will be involved and every case is different. The case of JD v Mather shows some of those difficulties and some of the issues the court will need to consider.