low weight(or BMI) is a risk factor for her2+ breast cancer

[Lani]

I previously posted an article which showed no correlation between post-treatment weight-gain and recurrence.

Others added that they had been thin or lost considerable weight prior to their diagnoses.

You may find this abstract from the European breast cancer conference in Nice last week interesting--it seems to me that it just shows that her2+ breast cancer is a different "beast" than other breast cancers!--don't know if this holds up in pre-menopausal her2 breast cancer :

Weight and body mass index (BMI) affect HER2 expression in postmenopausal breast cancer



Citation: European Journal of Cancer Supplements Volume 4, No. 2, March 2006, page 68

T. Van Mieghem1, K. Leunen1, N. Pochet2, B. De Moor2, F. Amant13, I. Vanden Bempt4, R. Drijkoningen4, M.R. Christiaens35, I. Vergote1, P. Neven13

1University Hospitals Leuven, Dept. of Obstetrics and Gynaecology, Leuven, Belgium
2KULeuven, ESAT, Leuven, Belgium
3University Hospitals Leuven, Multidisciplinary Breast Center, Leuven, Belgium
4University Hospitals Leuven, Dept. of Pathology, Leuven, Belgium
5University Hospitals Leuven, Dept. of Surgery, Leuven, Belgium

Background: In our population, HER-2 is expressed in 10.9% of primary breast cancers (J Clin Path 2005;58:611–6). Postmenopausal obesity is a risk factor for hormone sensitive tumours. These tumours are more likely HER-2 negative (Breast Cancer Res Treat 2005;91:81–7). We therefore hypothesised that postmenopausal obesity is associated with fewer HER-2 positive tumours.
Patients and Methods: Between January 1st 2002 and December 31st 2004, 549 postmenopausal women with a unilateral, not previously treated, operable breast cancer were evaluated the evening prior to operation for body weight, height, abdominal and hip circumference. Waist-to-hip ratio (WHR) and BMI [Weight/(Length in meters)2] were calculated. HER-2 staining was done by immunohistochemistry (MoAbCB11) and scored between 0 and 3+. HER-2 negativity was defined as 0, 1+ or 2+; HER-2 positivity as 3+. We compared HER-2 negative patients with HER-2 positive patients for all parameters of body composition and assessed the frequency of HER-2 positivity in each quartile from the lowest (Q1) to the highest (Q4) for these same parameters.
Results: Length and WHR were not significantly different between patients with HER-2 negative and HER-2 positive tumours. Abdominal and hip circumference were lower in HER-2 positive patients. This trend however, was not statistically significant. In Table 1 mean values for weight and BMI are compared between HER-2 negative and HER-2 positive patients. Table 2 shows the proportion of HER-2 positive tumours per quartile for weight and BMI in all patients.
Table 1. Comparison of mean values for weight and BMI between HER-2 negative and HER-2 positive patients

HER-2 negative HER-2 positive P-value
N Mean±SD N Mean±SD
Weight (kg) 474 69.19±13.18 58 65.09±11.29 0.0215
BMI (kg/m2) 472 26.98±9.21 56 24.93±4.27 0.0085
SD: standard deviation.


Table 2. Proportion of HER-2 positive tumours per quartile for weight and BMI in all patients (N = 549)

HER-2 positivity (%) P-value
Q1 Q2 Q3 Q4 (Q1–Q4)
Weight 16.30 10.32 9.93 6.92 0.0214
BMI 14.50 12.21 10.69 5.19 0.0127


Conclusion: Low weight and low BMI are risk factors for HER-2 positivity in postmenopausal women with breast cancer. The linear decrease in HER-2 positivity per increasing quartile for both parameters suggests our hypothesis may be correct. Larger numbers of HER-2 positive cases may be required to confirm our findings for other parameters of body composition.

[Christine MH-UK]

I would imagine that the link would hold for pre-menopausal breast cancer.

Pre-menopausal breast cancer is generally more common in thin women than fat ones. In fact, I read an article saying the rate of pre-menopausal breast cancer has actually decreased in the U.S. in recent years and one scientist linked it to the obesity epidemic.

My only concern is that if the message gets out that obesity causes breast cancer (which is true for the most common, post-menopausal variety) will thin women not realise they are at risk for her2?

Christine 'the stringbean' (my mother's nickname for me)

[RobinP]

Lani I just wanted to add that months ago I read an article which stated that if you are thin and use birth control you are at a higher risk for premenopausal breast cancer development than if you are normal weight or heavy. Accordingly, it appears that estrogen reaches toxic levels for those who are of lower body mass.

Additionally, a 2005 San Antonio Breast webcast suggested that high serum estrogen levels in study individuals resulted in later breast cancer development some 10-15 years later. I also recall an article that noted that lack of a gene allele involved with estrogen metabolism resulted in increased rates of breast cancer. Clearly, estrogen levels have a HUGE impact on later breast caner development. However, that is not to say that other factors do not have a role in breast cancer development, ig radiation exposure, environmental estrogen like carcinogens, diet, lack of certain oncogenes to prevent oncogenesis, etc.

Breast cancer is very very complex.

The working of the body are very complex.

Estrogen expression links into may of the bodies activities and systems including fat in take and particularly fat type and balance. Estrogen links with fatty acid making and utilisation systems, with insulin, leptin, weight control.........

My question after much reading is what is really in the driving seat in all of this. Estrogen is in there but is it the foot on the pedal, the cable, the injection system, the valves or the pistons (except in BC there are many more bits thousand probably all interlinking). Whose driving? My personal very amatuer guess is omega six being out of balance with omega three primarily is the foot on the pedal - are there links to oestrogen - yes, and lots of other factors beside. You can be fat or thin and have an omega three six imbalance. Those on low fat high polyunsaturates (veg oils margerine etc) superfit low weighters BY VIRTUE OF THEIR CONSUMPTION OF HIGH SIX SOURCES (VEG OILS) COMBINED WITH FAT AVOIDANCE (other very low level omega three sources at high volume eaten by heavier people) ARE ACTUALY MORE LIKELY TO HAVE A HIGH OMEGA 3 / 6 IMBALANCE, and hence a possible apparent link between lower body weight and HER2 I suggest.

CAN FATS HAVE SO MUCH IMPACT IN THE BODY - YES THEY CAN!! They have a huge range of functions act as hormones, controllers of all sorts of functions - FATS ARE HEAP POWERFUL.

Many of the functions fats insulin leptin estrogen................ are multiply related to each other and talk directly and indirectly to each other.

At a common sense level this suggests the need for a multiple approach combining chosen treatments with dietary improvements etc.

My overall perspective is even if the omega three six balance is not the driver (and somthing has to be - this growth in BC has not appeared out of nothing and nowhere, someting has changed) all balancing the omegas threes and sixes will do is generally is improve your health. ( Always check with advisers before considering significant dietary changes.)

RB

[Bev]

Hi, In their one paragraph summaries the media has made it seem like obesity and genetics are the cause of breast cancer. It has left me scratching my head as to how I fit in to their theories. RB... I'm not ruling out fat balance, I just haven't been able to understand it well yet, but I know if I keep reading I'll pick up more. And there could be a lot of interactions going on at once. I saw in the Wa Post that they're developing omega 3 pork for it's heart benefits. Thanks for posting the studies. BB

There is a link between obesity and BC and many inflamatory related diseases, but its a bit like blaming the truck with brake failure.

Fat balance contributes to weight problems, and in a sense is an expression of imbalance and excess consumption.

You see the truck piled into the side of the house, but in terms of cause the problem was not the truck it was what caused the truck to crash.

BC is being expressed it terms of the truck the make the shape etc, rather than the cause of the crash - which is rather less glamerous profitable and does not get researchers new research work - new drugs not cures and causes are what the profit driven industry requires. (which is not a criticism of the researchers Whom I am sure care passionately but the human dynamics)

If several trucks unexpectedly crash people want to know why.

We need to do the same in BC and deal with causes rather than looking for crash barriers etc.

RB

[kat in the delta]

Oh no, I never thought that not having enough fat would have anything to do with my being HER2 +++, I am very thin and have always dieted to remain thin. Now, I see I have caused harm to my body ?? Let me know more about Omega 6, and Omega 3 fatty acids. I've heard of O-3, but WHERE do you get Omega 6?? salmon, tuna, olive oil,...is Omega 3, right???kat RSVP

[R.B.]

Hi Kat.

I am always pleased to see somebody else interested in the issue of fat intake and the omega three six balance.

It is complex, and there is no real substitute for a bit of background reading to get the inklings of why many consider it a very significant issue, and why.

From my reading it is less about quantity and more about type and balance.

Try the post on articles of interest "the importance of omega three and six to breast cancer". There is a link to an article by a Ben Best, some of it is complex but just ignore what you dont understand and you should get the gist to start.

There are lots of posts on this site if you check out the search engine above and right, click on search and enter say omega three or six. There is lots on the net as well.

As you will see on the list of oils and compositions most oils are high to medium in omega six, with the exception of virgin olive oil and flax.

Omega three is found in high levels in flax seed / oil, perillia, oily fish fish oil, some algae etc.

The sixes promote inflamation and the threes moderate it in very general terms.

Historically balances of omega threes to omega six have been in the range of 4:1 to 1:4. Today it is 1:10 in some countries and in the US up to 1:50.

In general terms to balance the threes and sixes you have to cut out all oils except a little olive oil (virgin cold pressed) and flax to balance and provide threes. Getting your fats from whole foods has to be the starting place. SO read labels, and check out any other oils you feel the need for to see what they contain in terms of threes and sixes.

Trials suggest the KEY is balancing the threes and sixes.

DHA and EPA are two key omega three derivatives that the body can make but it is suggested in trials does not do very well especially when out of balance. So to help the body out you may want to consider taking some. Saddly for fish fish oil is a good source - about 2 grams a day appears to be a level at with the body's uptake drops off.

I recommend that you do a bit of background reading as it is just to big a subject to squeeze into a small space. There are also some posts on cancer diets on the site.

Fats are powerful agents in the body and have very many more functions than is generally realised and it is always sensible to discuss diet changes with your advisors.

If you are still lost come back.


RB