Doctor Varnava used to attend BreastScreen for the purpose of examining mammograms for a couple of hours on Friday, a couple of hours on Saturday and a couple of hours on Sunday.
72 Doctor Kitchener, a specialist radiologist gave expert evidence on behalf of the plaintiff. As previously indicated, Associate Professor Osborne was the expert witness for the defendant. Each doctor provided a number of reports and gave oral evidence. Their evidence was taken concurrently.
73 The defendant submitted that more weight should be given to the opinion of Associate Professor Osborne because he had greater experience in mammographic screening given his senior position with BreastScreen Queensland. While I accept that Associate Professor Osborne had more experience with the procedures and protocols followed by the BreastScreen organisation throughout Australia, I do not find that Associate Professor Osborne's expertise in the interpretation of mammograms and ultrasounds was any greater than that of Dr Kitchener. As is clear from the curricula vitae of both doctors, each is an experienced and highly qualified radiologist with a particular interest in breast imaging.
74 The resolution of their conflict of opinion cannot be achieved by reference to any superior expertise on the part of either of them.
75 The defendant submitted that greater weight should be given to the opinion of Associate Professor Osborne because of the methodology, which he used in preparing his first report. It was submitted that Associate Professor Osborne had commenced his analysis on a prospective basis, having available only that material which would have been available to the radiologists who examined the plaintiff's 2006 mammograms. He did not know the site of the cancer and other details concerning it.
76 The defendant contrasted that approach with that which was followed by Dr Kitchener. It submitted that he in reality was carrying out a retrospective analysis using as his start point the fact that a cancer had been found in the plaintiff's left breast in January 2007. The defendant submitted that it was obvious from Dr Kitchener's reports that he was unaware of the procedures followed by BreastScreen when conducting screening mammograms.
77 I am not persuaded that the suggested difference in approach gives any greater validity to the opinions of Associate Professor Osborne than to those of Dr Kitchener. It is quite obvious from the initial letters of instruction to Associate Professor Osborne that a cancer had been discovered after a report of normality had been received from BreastScreen by the plaintiff. The purpose for which his opinion was being sought would have been well understood by Associate Professor Osborne.
78 It was the opinion of Dr Kitchener that although there was no clear indication of the presence of a cancer in the plaintiff's 2006 mammogram, the combination of signs was such that a real suspicion existed as to the presence of a malignancy which required that the plaintiff be recalled for further assessment. Associate Professor Osborne agreed that had the 2006 mammogram been the first occasion that the plaintiff had attended for mammography, he would have recalled her for further assessment. When, however, the 2006 films were compared with either the 2004 or 2002 films his opinion was that the mass depicted in the 2006 mammogram was consistent with a benign cyst and that a recall of the plaintiff was not required. Associate Professor Osborne drew a distinction between the possibility of there being a malignancy which he said always existed where masses appeared on mammography, and a positive indication of malignancy such as spiculation or distortion of the mass.
79 There was an important factual issue between Dr Kitchener and Associate Professor Osborne which requires resolution. This was the extent of the change in the size of the mass which was found in the 2006 mammogram when compared with the same mass in either the 2002 or 2004 mammograms. It was Dr Kitchener's opinion that when one measured the dimensions of the mass in the 2006 mammogram and compared its size with the dimensions of the same mass in the 2004 mammogram, it had approximately doubled in size between 2004 and 2006. Associate Professor Osborne in his report said that the mass in 2006 was approximately the same size as it had been in 2004 but that it was more dense in appearance. In his oral evidence, he essentially maintained that position but did concede, "it could be marginally bigger" (T.125.1).
80 The question of whether the mass had increased in size between 2002/4 and 2006, and if so to what extent, became a matter of fundamental importance at the trial. It is a factual issue which I must decide. In doing so, it is necessary to set out in more detail the opinions of Associate Professor Osborne and Dr Kitchener and in particular those matters upon which they agreed and those matters upon which they disagreed.
81 In relation to the 2002 mammogram, the doctors agreed that there were two masses present; a smaller anterior mass and a larger posterior mass. They agreed that there was fine scattered calcification, but that the calcification was not "clustered", i.e. concentrated in close relationship. There was no evidence of suspicious features such as spiculated lesions or distortion. Doctor Kitchener noted two matters, which Associate Professor Osborne did not refer to. They were some lateral lobulation in the larger mass and some indistinct margins. The significance of an indistinct margin was that the "halo" sign to which Associate Professor Osborne had referred did not apply to the whole of the posterior mass in that some of the margins of that mass were indistinct, i.e. could not be observed. Doctor Kitchener agreed that the part of the mass which had the "halo", would be benign but in respect of the part that did not have the "halo" around it, i.e. the part with the indistinct margin, one could not tell.
82 In relation to the indistinct margins of the posterior mass, Associate Professor Osborne said:
"In general I agree with Dr Kitchener except that when one talks about an indistinct margin there may be a number of reasons why it is indistinct. It may be there is actually tumour that is growing out and that is, I agree totally, that is a positive sign of malignancy.
What it also might be is that the cyst or other benign structure that Dr Kitchener has described as having a halo, it very seldom arises in isolation. The breasts are almost always, some have varying degrees of breast density. Now, the cyst or benign structure may be growing out of that tissue and in that case you will not see the margin. It might be that in fact the cyst, it is a fluid filled structure, might be actually squashed down so in that respect it will be indistinct. It might be, there are other reasons why the margins may be indistinct. It is one of the problems with mammography.
There are positive signs which say yes, that is a cancer. But to say that the absence of signs or negative signs to say therefore that is something that is definitely not benign and therefore we have to investigate them. The reality is there is such a wide range of normal breast tissues that there is, best say if you look under a bell curve there is such, there is a wide range of benign tissues there is also a wide range of malignant tissues and there is a degree of overlap.
That is what we actually argue about and it is a total appearance of what is going there. So indistinct margins, it is like fine calcification. These are negative signs or negative descriptions that are a lot harder to pin down. They are not positive ones." (T.101.40-102.15)
83 Doctor Kitchener explained what he meant by lobulation as follows:
"Lobulation can occur in cysts. It occurs in solid lesions also where there has been an outgrowth. The cyst is usually a spherical structure, it is a simple lesion unless there are two or three cysts sitting adjacent to each other, then the cysts will appear lobular. But in the past it appears almost as a spherical structure and by 2006 there was a bunch, a lobule sticking out from it." (T.117.15)
84 At no time in the course of the oral evidence did Associate Professor Osborne challenge the proposition that there were some indistinct margins on the posterior mass, nor did he challenge the presence of lobulation, either in 2002 or in 2006. He did, of course, challenge their significance. It is surprising that Associate Professor Osborne did not refer to those features in his reports.
85 In relation to the 2004 mammogram, the doctors agreed that there had been no change in the size of the posterior mass since 2002. Associate Professor Osborne made no mention of there being slightly indistinct margins on parts of that mass, but in oral evidence accepted that to be the case. Doctor Kitchener referred to what he described as a "posteromedial inferior band of tissue which had increased in size". Associate Professor Osborne accepted that the band of tissue was observable on the 2004 mammogram but was not sure that there had been any increase in size. Associate Professor Osborne did not see any particular significance in the presence of such a band of tissue. He thought that it could be explained by the position of the mammogram when the film was taken or by hormonal changes which could take place in two years, particularly in a younger woman.
86 In relation to the significance of calcification, if present, the doctors were generally in agreement. Doctor Kitchener said:
"Most calcification in the breasts, as he said, are benign and the larger the calcifications the more benign they are and the smaller and finer the calcifications are the more likely they become to be malignant micro calcification. So sometimes malignant micro calcifications are perfectly obvious in that there are certain signs of them in clustering, linear branching. There are some signs that make them malignant. There are none of those signs present in 2004." (T.110.15)
87 Associate Professor Osborne said:
"Now the calcifications within the glands are these really very fine calcifications that can be clustered - sorry, can be scattered and are not clustered because the glands are quite widespread. The calcification we worry about is calcification that is actually within the ducts and the worst sort that we worry about is when the tumour is actually spreading along the duct and that's what we call ductal carcinoma in situ and the surface of the duct falls away and into the lumen of the duct and that calcification is like sort of sludge within a tube, and that's what we call casting calcification. That is the obvious calcification that Dr Kitchener talked about and I would expect a junior doctor to pick that as malignant. Then you get the harder sorts of calcification where it's not as definite and it can be just clustered in certain points. The calcification is somewhat irregular, classically sort of described as needlepoint or crushed stone appearance. Now, if you see a cluster of that you are quite worried. But then we have got an even earlier stage that is really quite hard to pick. What we then look for, and I agree with Dr Kitchener, that you look at the total pattern. Now, when I said that the calcification is essentially unchanged I was talking about this, the fact that there is calcification is fine and is scattered throughout the breast tissue. That pattern is that of the calcification within the glands themselves and that's a benign pattern. I didn't refer to the calcification in one particular area or another particular area. There is this pattern throughout and this is benign.
DR KITCHENER: The only problem that I see, I basically in general am in agreement, but one does get to a point where the calcification that is malignant has to be begin somewhere and if we are looking at the very earliest stages of seeing one punctate area of calcification that when you are looking at these things over a series and you start to see one calcification and closer by a second one, although it is not typical of malignant calcification it does have to raise your level of suspicion a touch." (T.110.30-111.11)
88 Where the two doctors differed significantly was in relation to the 2006 mammogram. The most obvious point of difference was whether or not the posterior mass had significantly increased in size between 2004 and 2006. Both doctors agreed that the smaller anterior mass had entirely disappeared by February 2006 which confirmed that it had been a cyst.
89 Doctor Kitchener set out the dimensions of the mass as he saw it in 2006 at 35 by 30 by 28 millimetres. Associate Professor Osborne opined in his report, and in his oral evidence, that the posterior mass in 2006 was approximately the same size as in 2004. Later in his oral evidence he said that the 2006 mass could be marginally bigger.
90 In support of his opinion, Associate Professor Osborne pointed out that one of the disadvantages of mammography is that it is difficult to make measurements based on it. In response, Dr Kitchener said that the difference in size was so obvious that there was no need to engage in any precise measurements, even though he had done so.
91 In order to clarify the question, the 2006 films and the 2004 films were placed on an x-ray machine in court. Film number 3 of the 2006 scans was a CC view. Films 1 and 2 of the 2004 scans were CC views. Doctor Kitchener relied particularly upon a comparison of film number 1 of the 2004 series and film number 3 of the 2006 scans. (T.125.23) Associate Professor Osborne pointed out on the films those parts of the mass which he believed showed that visually there was no change in the size of the mass between the 2004 and 2006 mammograms.
92 As a lay person I found that the comparisons of the size of the mass in the films on which Dr Kitchener relied clearly demonstrated to the naked eye that the 2006 mass was significantly larger. In that regard I appreciate my limitations in that I am not experienced in interpreting mammographic films. I cannot, however, ignore my observation that on a simple visual comparison the mass on the 2006 films appeared significantly larger than that on the 2004 films.
93 Some support for the conclusion of Dr Kitchener on this issue is provided by the evidence of Dr Varnava in relation to the 2006 mammogram. At para 30 he noted that "the previously reported 2.5 cm mass seen in the midline approximately 8 cm from the nipple has increased in size to 3 cm". Even if the other dimensions had remained unchanged, this represents an increase in size of approximately 20%.
94 Further support is provided by Professor Levi, the oncologist qualified on behalf of the plaintiff. In his report of 27 November 2007 (exhibit P) at page 2 Professor Levi had this to say about the 2006 mammogram:
"The mammogram of 23rd February 2006 clearly shows an irregular, fairly well circumscribed density within the upper part of the breast centrally. The measurements taken by myself of this mass are 3 by 3.5 cm.
I essentially agree with the report of Dr Peter Kitchener in relation to the mammogram of 23 February 2006 that the mass is obvious."
95 The measurements independently taken by Professor Levi coincide with two of those recorded by Dr Kitchener but which were challenged by Associate Professor Osborne.
96 In determining this issue, I have also taken into account my assessment of the respective witnesses. Both doctors strongly supported their respective points of view. I found Dr Kitchener, however, ready to make concessions where appropriate, and to approach the questions with a rather more open mind than Associate Professor Osborne. In the case of Associate Professor Osborne I felt that he was very protective of the BreastScreen procedures and that this did inevitably colour his responses. Generally speaking, although both witnesses sought to assist the Court, I found Dr Kitchener's approach to be more considered and reasonable.
97 A notable feature of the evidence of Dr Kitchener was the rather quiet and deprecatory way in which it was given. On this issue, however, Dr Kitchener became quite animated and not only was the discussion between the doctors vigorous, it was apparent that Dr Kitchener had no doubts about the correctness of his opinion.
"WITNESS KITCHENER: This is certainly a true craniocaudal view. So this is a partial view of the same. These two, number one and number two, are craniocaudal and number three and number four are mediolateral. If you just compare the size of the mass there to the size of the mass there, I don't think it requires a measurement to tell the difference.
WITNESS OSBORNE: On the contrary. I think if you take that measurement there to that measurement there which is going through one, two, three, four and that measurement there to there, it is still going through one, two, three, four. What I suggested was that they were approximately the same size. I have got no problems that it could be marginally bigger but what I am saying is that this actually appears denser, easier to see, and therefore as it is easier to see one can see the margins more clearly. But if you actually go from there to there and there to there, it is still approximately the same size, but it is denser.
HIS HONOUR: I will just continue with Dr Kitchener. You have heard what Professor Osborne says. Do you agree with that?
WITNESS KITCHENER: Not at all. If you look at this image there you can see the margins of the mass perfectly clearly. You can see the back of it and the front of it. If there is some discussion of where the top end of it and the bottom end is, you can certainly see the front and back and you can certainly see the front and back there.
HIS HONOUR: What about the MLO images it doesn't seem as clear there.
WITNESS KITCHENER: I think it is clear enough. There is an anterior margin and there is a posterior margin. You can certainly see an anterior margin down there, and posterior margin down here.
HIS HONOUR: You used that to work out your calculations?
WITNESS KITCHENER: Yes. This one in particular, there is just no doubt in my mind.
HIS HONOUR: You are comparing number one of the 2004 series with number three of the 2006 scans.
WITNESS KITCHENER: Yes." (T.124.41-125.29)
98 I cannot accept the opinion of Associate Professor Osborne that the size of the mass in 2006 was approximately the same as in 2004. There is no support for this opinion other than Associate Professor Osborne's own assertion. Leaving aside the assessments of Dr Kitchener and Professor Levi, and my own observation of the mammogram films, this opinion is clearly in conflict with that of Dr Varnava. Dr Varnava's measurement of one of the dimensions showed an increase of at least 20%. In my opinion, a difference of 20% cannot be correctly characterised as "approximately the same size".
99 On this issue I am satisfied that the opinion of Associate Professor Osborne is incorrect and I prefer the evidence of Dr Kitchener. Doctor Kitchener's evidence is substantially supported by that of Professor Levi and as to one measurement at least, by Dr Varnava. It also accords with my own observation of the mammographic scans. Once the opinion of Associate Professor Osborne is rejected, the only guidance which I have is the assessment of Dr Kitchener that the 2006 mammogram showed that the posterior mass had approximately doubled in size since the 2004 mammogram. That is the finding which I make.
100 When the trial started there was an issue between the parties as to whether the tumours in the plaintiff's lungs and brain had metastasised from her breast cancer or whether the tumours in her lungs were a primary cancer which had metastasised to her brain. Relevant to that issue was the fact that the plaintiff had been a heavy smoker until her breast cancer was diagnosed.
101 This issue went away after the report of Professor Bilous (exhibit T) was shown to Professor Tattersall, the oncologist qualified by the defendant. The defendant acknowledged that the tumours in the plaintiff's lungs and brain had metastasised from the breast cancer.
102 Professor Bilous is an expert in tissue pathology. His analysis of the tumours in the plaintiff's breast and lungs confirmed a similarity in their cell structure sufficient to establish that they were linked. The defendant's concession was properly made and was yet another example of the spirit of co-operation which was demonstrated between the parties. It is not without significance that the report from Professor Bilous was obtained by the defendant.