I'm at the American Society of Clinical Oncology (ASCO) annual meeting down in Orlando, Florida. This gathering is a forum for sharing developments in oncology. The first day's sessions were all about education, and were a bit disappointing because there wasn't much new that was presented. Here, though, are the highlights from Day 1:

Bispohosphonates:  This session focused on osteoporosis and its treatment, particularly as it overlaps with cancer. I had high hopes for the discussion, though they were quickly dashed. It was a standard talk with nothing new. I was particularly struck with the fact that we are still treating a test (bone density) and not using fractures as an end point when we discuss osteoporosis treatment with bisphosphonate.  

The data show that women who take aromatase inhibitors lose bone, but that it returns when they stop the drugs. Do we really have to give them bisphosphonates to prevent the loss if it is temporary, particularly if we don't know the long term consequences of this drug?

More intriguing is a study that was done on premenopausal women who were put into temporary menopause with goserilin and then randomized to either tamoxifen or an aromatase inhibitor followed by another randomization, to either a bisphosphonate or a placebo. Apart from the fact that this is a lot of drugs for a cancer that has a 98% survival rate, the results were interesting in what they teach us about this disease. 

First there was no difference between the aromatase inhibitor and tamoxifen, probably because the premenopausal women were already in temporary menopause. Second, and more interesting, was the fact that the disease-free survival was better in either group when a bisphosphonate was added. This changes the picture. Maybe we should be giving bisphosphonates as cancer treatment rather than to treat the bone density test. Why would we get this result? I don’t think we know. Could it be that bisphosphonates have an effect not just on osteoclasts, but also on the stroma? Interesting...

Sentinel nodes: Really not much new here other than the fact that you can still get lymphedema and/or numbness after a sentinel node biopsy. There's still much controversy about whether to do sentinel node biopsy in cases of DCIS, although it doesn’t appear to add much other than side effects. There was also little consensus on whether to do sentinel node at time of recurrence of the DCIS.

MRI:  This session, too, had little new other than the fact that it was a careful review of the data of the use of MRI in women diagnosed with cancer. Basically, MRI can be used to monitor the size of breast cancers that are treated first with chemotherapy, IF they are the right kind of cancer. MRI doesn't work on all cancers and has both false positives and negatives.

But what about MRI in women who are newly diagnosed? An excellent review of the data by Dr. Houssami concluded that MRI does not add an incremental benefit in the treatment of the disease. In large part this is because MRI finds two benign lesions for every cancer (mostly small and insignificant in someone planning to have radiation) and leads to conversion to more extensive surgery 11% of the time. In half of these cases, this is based on a false positive. 
Dr. Houssami looked at whether it improved surgical planning, decreasing the re-excision rate of a biopsy. The answer, again, is that there is no evidence that pre- operative MRI affects clinical outcome. 

Dr. Houssami reviewed whether a pre-operative MRI was beneficial in finding disease in the other breast. The use of MRI preoperatively found 9.3% of suspicious lesions in the other breast and only half of them were actually cancer. MRI detects mostly 'good' cancers and it is certainly not clear whether they are clinically significant. 

Finally there was a review of whether preoperative MRI leads to a lower local recurrence rate. In other words, does MRI make the surgery better so that the woman will not have a recurrence in her breast? The results were not surprising to those of us who were on the front end of breast conservation. We always knew there were small tumors elsewhere in the breast and that was why whole breast radiation was added. This study showed a local recurrence rate of 3-4% whether an MRI was used preoperatively. A randomized study showed no difference, as well. The point is that the local recurrence rate after breast conservation is very low and MRI does not improve it. The conclusion -- and one I agree with -- is that pre-operative MRI adds little to pre-operative planning and does not improve the outcomes of local treatment. I am sure it is not cost effective (study not yet done) and we really have to stop routinely using this expensive imaging tool.

Vitamin D: Saturday morning found me in another educational session, this one on Vitamin D.  After reviewing the data the conclusion was that this topic was complex and that it was not clear that low Vitamin D levels were related to breast cancer risk apart from physical activity and BMI. There is also data that you can have too much Vitamin D, as with everything it is a U shaped curve with problems at both ends of the spectrum. 

The session confirmed my suspicion that the hype about Vitamin D is premature.  The best thing we can do to prevent breast cancer is exercise, but maybe doing it outdoors will give double the benefits!